Comparison of metabolic and heart rate responses to super slow vs. traditional resistance training

In order to compare the cardiovascular and energy expenditure demands of "Super Slow" (SST) and traditional (TT) resistance training 7 resistance-trained young men (24.3 +/- 3.8 years) had energy expenditure (using indirect calorimetry) and heart rate evaluated during and for 15 minutes after a workout on separate days. Blood lactate levels were also evaluated before and after each intervention. Resting energy expenditure was evaluated in a fasted state using a ventilated canopy prior to any exercise stimulus and 21 to 22 hours after the SST and TT. VO(2) and average heart rate were both significantly higher during the TT than during the SST. The net VO(2) was also significantly higher during the 15 minutes recovery; however, average heart rate was not significantly different between the 2 groups. Total net energy expenditure from oxidative processes was 45% higher for the TT intervention (TT = 155 +/- 28 kcal, and SST = 107 +/- 20 kcal). The significant postexercise lactate difference was almost 2 times greater following the TT than after the SST (TT = 7.9 +/- 1.7 mmol.L(-1).min(-1), and SST = 4.0 +/- 2.0 mmol.L(-1).min(-1)). Finally, adding the estimated energy expenditure of the blood lactate to the net energy expenditure from the VO(2) produced a significant difference that is over 48% greater for the TT intervention (TT = 172 +/- 29 kcal.min(-1), and SST = 116 +/- 22 kcal.min(-1)). No significant repeated measures analysis main effect was found for either resting energy expenditure or respiratory exchange ratio. The metabolic and cardiovascular stimuli were low with SST. Traditional resistance training increases energy expenditure more than SST does and thus may be more beneficial for body weight control.     

Promoter Hypermethylation-Related Reduced Somatostatin Production Promotes Uncontrolled Cell Proliferation in Colorectal Cancer

BackgroundSomatostatin (SST) has anti-proliferative and pro-apoptotic effects. Our aims were to analyze and compare the SST expression during normal aging and colorectal carcinogenesis at mRNA and protein levels. Furthermore, we tested the methylation status of SST in biopsy samples, and the cell growth inhibitory effect of the SST analogue octreotide in human colorectal adenocarcinoma cell line.MethodsColonic samples were collected from healthy children (n1 = 6), healthy adults (n2 = 41) and colorectal cancer patients (CRCs) (n₃ = 34) for SST mRNA expression analysis, using HGU133 Plus2.0 microarrays. Results were validated both on original (n₁ = 6; n₂ = 6; n₃ = 6) and independent samples ((n₁ = 6; n₂ = 6; n₃ = 6) by real-time PCR. SST expressing cells were detected by immunohistochemistry on colonic biopsy samples (n₁ = 14; n₂ = 20; n₃ = 23). The effect of octreotide on cell growth was tested on Caco-2 cell line. SST methylation percentage in biopsy samples (n₁ = 5; n₂ = 5; n₃ = 9) was defined using methylation-sensitive restriction enzyme digestion.ResultsIn case of normal aging SST mRNA expression did not alter, but decreased in cancer (p<0.05). The ratio of SST immunoreactive cells was significantly higher in children (0.70%±0.79%) compared to CRC (0%±0%) (p<0.05). Octreotide significantly increased the proportion of apoptotic Caco-2 cells. SST showed significantly higher methylation level in tumor samples (30.2%±11.6%) compared to healthy young individuals (3.5%±1.9%) (p<0.05).ConclusionsIn cancerous colonic mucosa the reduced SST production may contribute to the uncontrolled cell proliferation. Our observation that in colon cancer cells octreotide significantly enhanced cell death and attenuated cell proliferation suggests that SST may act as a regulator of epithelial cell kinetics. The inhibition of SST expression in CRC can be epigenetically regulated by promoter hypermethylation.     

Selective regulation of somatostatin receptor subtype signaling: evidence for constitutive receptor activation

Anterior pituitary hormone secretion is under tonic suppression by hypothalamic somatostatin signaling through somatostatin receptor subtypes (SSTs). Because some hormonal axes are known to be abnormally regulated by ligand-independent constitutively active G protein-coupled receptors, we tested pituitary SSTs for selective constitutive signaling. We therefore differentially silenced endogenous SST2, SST3, and SST5 in somatostatin-sensitive ACTH-secreting mouse AtT-20 pituitary corticotroph cells using small inhibitory RNA (siRNA) and analyzed downstream SSTs-regulated pathways. Transfection with siRNA reduced specific receptor subtype mRNA expression up to 82%. Specificity of receptor silencing was validated against negative controls with different gene-selective siRNAs, concordance of mRNA and cAMP changes, reduced potency of receptor-selective agonists, and phenotype rescue by overexpression of the silenced receptor. Mouse SST3 > SST5 > SST2 knockdown increased basal cAMP accumulation (up to 200%) and ACTH secretion (up to 60%). SST2- and SST5-selective agonist potencies were reduced by SST3- and SST5-silencing, respectively. SST5 > SST2 = SST3 silencing also increased basal levels of ERK1/2 phosphorylation. SST3- and SST5-knockdown increased cAMP was only partially blocked by pertussis toxin. The results show that SST2, SST3, and SST5 exhibit constitutive activity in mouse pituitary corticotroph cells, restraining adenylate cyclase and MAPK activation and ACTH secretion. SST3 mainly inhibits cAMP accumulation and ACTH secretion, whereas SST5 predominantly suppresses MAPK pathway activation. Therefore, SST receptor subtypes control pituitary cell function not only through somatostatin binding to variably expressed cell membrane receptor subtypes, but also by differential ligand-independent receptor-selective constitutive action.     

Expanding syphilis test uptake using rapid dual self-testing for syphilis and HIV among men who have sex with men in China: A multiarm randomized controlled trial

BackgroundLow syphilis testing uptake is a major public health issue among men who have sex with men (MSM) in many low- and middle-income countries. Syphilis self-testing (SST) may complement and extend facility-based testing. We aimed to evaluate the effectiveness and costs of providing SST on increasing syphilis testing uptake among MSM in China.Methods and findingsAn open-label, parallel 3-arm randomized controlled trial (RCT) was conducted between January 7, 2020 and July 17, 2020. Men who were at least 18 years of age, had condomless anal sex with men in the past year, reported not testing for syphilis in the last 6 months, and had a stable residence with mailing addresses were recruited from 124 cities in 26 Chinese provinces. Using block randomization with blocks of size 12, enrolled participants were randomly assigned (1:1:1) into 3 arms: standard of care arm, standard SST arm, and lottery incentivized SST arm (1 in 10 chance to win US$15 if they had a syphilis test). The primary outcome was the proportion of participants who tested for syphilis during the trial period and confirmed with photo verification and between arm comparisons were estimated with risk differences (RDs). Analyses were performed on a modified intention-to-treat basis: Participants were included in the complete case analysis if they had initiated at least 1 follow-up survey. The Syphilis/HIV Duo rapid test kit was used. A total of 451 men were enrolled. In total, 136 (90·7%, 136/150) in the standard of care arm, 142 (94·0%, 142/151) in the standard of SST arm, and 137 (91·3%, 137/150) in the lottery incentivized SST arm were included in the final analysis. The proportion of men who had at least 1 syphilis test during the trial period was 63.4% (95% confidence interval [CI]: 55.5% to 71.3%, p = 0.001) in the standard SST arm, 65.7% (95% CI: 57.7% to 73.6%, p = 0.0002) in the lottery incentivized SST arm, and 14.7% (95% CI: 8.8% to 20.7%, p < 0.001) in the standard of care arm. The estimated RD between the standard SST and standard of care arm was 48.7% (95% CI: 37.8% to 58.4%, p < 0.001). The majority (78.5%, 95% CI: 72.7% to 84.4%, p < 0.001) of syphilis self-testers reported never testing for syphilis. The cost per person tested was US$26.55 for standard SST, US$28.09 for the lottery incentivized SST, and US$66.19 for the standard of care. No study-related adverse events were reported during the study duration. Limitation was that the impact of the Coronavirus Disease 2019 (COVID-19) restrictions may have accentuated demand for decentralized testing.ConclusionsCompared to standard of care, providing SST significantly increased the proportion of MSM testing for syphilis in China and was cheaper (per person tested).Trial registrationChinese Clinical Trial Registry: ChiCTR1900022409.

In a multi-arm randomized controlled trial, Cheng Wang and colleagues determine the effectiveness and cost of expanding syphilis self testing among men who have sex with men in China.     

Association between serum somatostatin levels and glucose-lipid metabolism in the Jino ethnic minority and Han Chinese population

We aim to investigate the relationship between serum somatostatin(SST) levels and glucose-lipid metabolism at various stages of glucose tolerance in the Jino ethnic minority(n=111) and Han population(n=113) of Yunnan Province, southwest China.Anthropometric parameters and biochemical traits were measured. Serum SST and plasma glucagon levels were tested. Participants were divided into three subgroups: isolated fasting hyperglycemia(IFH), isolated post challenge hyperglycemia(IPH)and normal glucose tolerance(NGT). SST levels were found lower while glucagon levels were significantly higher in the Jino ethnic with IPH(P=0.0026 and P=0.0069, respectively). Fasting glucose and high density lipoprotein-cholesterol(HDL-C)levels were higher(P=0.0055 and P=0.0021, respectively) and fasting insulin levels and homeostasis model assessments β-cell function were lower(P=0.0479 and P=0.0007, respectively) in the Jino population. After adjusting for confounding factors, the serum SST level was associated with glucagon(P0.0001) in both populations. The SST level was correlated with fasting Cpeptide(P=0.0267) in Jino and HDL-C levels in Han(P=0.0079). Our findings suggest that serum SST levels and plasma glucagon levels may vary in subjects with IPH between two ethnics.     

Influence of contraction velocity in untrained individuals over the initial early phase of resistance training

The purpose of this study was to determine the early phase adaptations in short-term traditional (TRT) versus superslow (SST) resistance training. Sixteen apparently healthy subjects participated in this study. Subjects were pretested and posttested for their 1 repetition maximums (1RM) in the squat and bench press, peak power in a countermovement jump (CMJ) and squat jump (SJ), and body composition using dual energy x-ray absorptiometry. Subjects participated in an 8-week resistance training program in either SST (n = 9, 3 men, 6 women), using 50% of 1RM, or TRT (n = 7, 3 men, 4 women), using 80% of 1RM. Both groups trained 3 days per week. The TRT and SST groups improved in strength by 6.8 and 3.6% in the squat exercise and by 8.6 and 9.1% in the bench press, respectively. Peak power for the CMJ increased significantly in the TRT group, from 23.0 +/- 5.5 W/kg to 25.0 +/- 6.3 W/kg; no such increase was seen with respect to the SST group. Both groups' 1RM increased significantly for both the bench press and the squat. No changes in body composition were seen for either group. The results of this study suggest that TRT is more effective for improving peak power than SST.     

Predicting Recovery Of The Hypothalamic-Pituitary-Adrenal Axis After Prolonged Glucocorticoid Use

Objective: Prolonged exposure to glucocorticoids lead to hypothalamic-pituitary-adrenal (HPA) axis suppression that recovers after cessation of treatment. We aimed to identify the predictive factors for HPA axis recovery after prolonged glucocorticoid use.Methods: Retrospective review of patients who had undergone first short Synacthen test (SST) to assess HPA axis recovery after prolonged use of glucocorticoids.Results: A total of 61% (20/33) of patients had adequate SST response at a median time of 2 years after diagnosis of adrenal insufficiency. Those who had adequate response during SST had higher ambulatory early morning cortisol (P<.01), shorter duration of exposure to glucocorticoids (P = .01), and lower final cumulative hydrocortisone replacement dose (P = .03). Age, gender, body mass index, indications for glucocorticoid use, and basal adrenocorticotropic hormone levels were not predictive of HPA axis recovery. On multivariate analysis, ambulatory early morning cortisol was the only independent predictor of adequate SST response (odds ratio, 1.02; 95% confidence interval, 1.01 to 1.04; P = .02). Using receiver operating characteristic curve analysis, ambulatory early morning cortisol of 8.8 μg/dL predicted a positive SST response with a sensitivity of 70% and specificity of 93%.Conclusion: Early morning ambulatory cortisol could be used to decide on timely SST in order to prevent complications from unnecessary replacement with glucocorticoids.Abbreviations: ACTH = adrenocorticotropic hormone; BMI = body mass index; CV = coefficient of variation; HPA = hypothalamic-pituitary-adrenal; SST = short Synacthen test     

Quantification of spermatozoa in the sperm-storage tubules of turkey hens and the relation to sperm numbers in the perivitelline layer of eggs

This study was conducted to determine the number of spermatozoa residing in the oviduct sperm-storage tubules (SST) and the relationship between these numbers and the number of spermatozoa embedded in the perivitelline layer of oviductal eggs after a single insemination of 200 x 10(6) spermatozoa. The SST of hens inseminated within one week before the expected onset of egg production were filled faster (4 h vs. 2 days) and possessed more spermatozoa (4.1 vs. 2.0 x 10(6)) than the SST of hens inseminated after the onset of egg production. Furthermore, for hens in egg production, significantly fewer spermatozoa were recovered from the SST if the hen was inseminated within 2 h before or after oviposition than if inseminated more than 2 h before or after the oviposition. There was a strong positive correlation between the number of spermatozoa in the SST and the number of spermatozoa embedded in the perivitelline layer of the oviductal eggs (r = 0.85, p less than 0.01). These data show that the population of spermatozoa actually accepted by the SST is quite small relative to the number of spermatozoa inseminated and that maximum sperm-storage is achieved when the hen is inseminated just prior to the onset of egg production. It is suggested that the sperm-storage capacity of the oviduct and the quality of the semen sample can be estimated on the basis of numbers of spermatozoa embedded in the egg perivitelline layer.     

Brain somatostatin receptor-G protein interaction. G alpha C-terminal antibodies demonstrate coupling of the soluble receptor with Gi(1-3) but not with Go.

Somatostatin (SST) receptors activate potassium channels, stimulate protein phosphatases, inhibit adenylate cyclase and close calcium channels. These multiple effects are controlled by guanine nucleotide binding (G) proteins of the pertussis toxin-sensitive Gi and Go types. In the present study we have identified the G proteins coupling with brain SST receptors. To this end, brain SST receptors were solubilized in G-protein coupled form. Binding of the SST analogue MK 678 to the solubilized receptor was completely inhibited by guanosine 5'-O-thiotriphosphate (IC50 = 100 nM), reflecting decreased receptor affinity for agonist following uncoupling of the receptor and G protein(s). Antibodies raised against specific COOH-terminal peptides of the G proteins Gi(1-3), Go, and Gz were used to probe for SST receptor-G protein coupling in this system. Antibodies binding to the COOH-terminal regions of Gi1 and Gi2 (antibody AS) and Gi3 (antibody EC) inhibited binding of 125I-MK 678 (75 pM) by 57 +/- 4% and 48 +/- 5%, respectively. The effects of these antibodies were concentration-dependent and additive, such that in combination AS and EC completely inhibited binding. Antibodies binding to the COOH-terminal region of Go (GO) and Gz (QN) did not affect binding of 125I-MK 678, indicating that neither Go nor Gz are associated with the brain SST receptor. Prelabeling of the receptor with 125I-MK 678 prior to addition of antibody induced the formation of a "locked conformation" of the agonist-bound receptor-G protein complex which was insensitive to antibody. In conclusion, Gi1 and/or Gi2 and Gi3 are coupled in approximately equal proportions to the brain 125I-MK 678-binding SST receptor, accounting for all of the G protein coupling of this receptor.     

Endocrine and thermal responses to GnRH treatment and prediction of sperm output and viability in holstein-Friesian breeding bulls

A study was conducted to determine changes in serum LH and testosterone concentrations and in scrotal surface temperature (SST; measured with infrared thermography) following GnRH treatment and to predict the number of spermatozoa collected and the proportion that were viable. Holstein-Friesian breeding bulls (n = 22, average age, 24.3 m.o.; range, 15 to 41 m.o.) were examined twice 30 d apart. Concurrently, semen was collected twice weekly with an artificial vagina. Treatment with GnRH (100 micrograms, i.m.) increased (P < 0.0001) serum LH and testosterone concentrations and increased (P < 0.0001) SST (range 0.6 to 1.1 degrees C; P < 0.05) at the top and bottom of the scrotum. In regression models to predict the total number of spermatozoa, significant independent variables included ultrasonic echotexture of the testes (negative slope), scrotal width (positive slope) and SST at the bottom of the scrotum 45 min after GnRH treatment (positive slope). In regression models to predict the percentage of live spermatozoa, ultrasonic echotexture was a significant independent variable (negative slope). Measurement of testicular ultrasonic echotexture and SST after GnRH treatment augmented measurement of testicular size for predicting the number and percentage of live spermatozoa.     

Spatial patterns and scaling behaviors of Steller sea lion (Eumetopias jubatus) distributions and their environment

Fractal geometry and other multi-scale analyses have become popular tools for investigating spatial patterns of animal distributions in heterogeneous environments. In theory, changes in patterns of animal distributions with changes in scale reflect transitions between the controlling influences of one environmental factor or process over another. In an effort to find linkages between Steller sea lions (Eumetopias jubatus) and their environment, the objective of this study was to determine if the spatial distribution of Steller sea lions at sea displayed similar scaling properties to the variation of two environmental features, including bathymetry and sea surface temperature (SST). Additionally, distributions of Steller sea lion point patterns were examined with respect to measurements of bathymetric complexity. From February 2000 to May 2004, satellite transmitters were deployed on 10 groups of juvenile Steller sea lions (n=52) at eight different locations within the Aleutian Islands and Gulf of Alaska. Indices of fractal dimension were calculated for each group of sea lions using a unit square box-counting method, whereas indices of bathymetry and SST patchiness were derived by conducting a variance ratio analysis over the same scales. Distributions of Steller sea lions at sea displayed self-similar fractal patterns, suggesting that individuals were distributed in a continuous hierarchical set of clumps within clumps across scales, and foraging behavior was likely influenced by a scale invariant mechanism. Patterns of bathymetric variability also were self-similar, whereas patterns of SST variability were scale dependent and failed to retain self-similar spatial structure at larger scales. These results indicate that the distributions of Steller sea lions at sea were more influenced by bathymetry than SST at the scales examined, but scale-dependent patterns in the distribution of Steller sea lions at sea or linkages with SST may have been apparent if analyses were conducted at finer spatial scales.     

Somatostatin and its receptors contribute in a tissue-specific manner to the sex-dependent metabolic (fed/fasting) control of growth hormone axis in mice

Somatostatin (SST) inhibits growth hormone (GH) secretion and regulates multiple processes by signaling through its receptors sst1-5. Differential expression of SST/ssts may contribute to sex-specific GH pattern and fasting-induced GH rise. To further delineate the tissue-specific roles of SST and sst1-5 in these processes, their expression patterns were evaluated in hypothalamus, pituitary, and stomach of male and female mice under fed/fasted conditions in the presence (wild type) or absence (SST-knockout) of endogenous SST. Under fed conditions, hypothalamic/stomach SST/ssts expression did not differ between sexes, whereas male pituitary expressed more SST and sst2A/2B/3/5A/5TMD2/5TMD1 and less sst1, and male pituitary cell cultures were more responsive to SST inhibitory actions on GH release compared with females. This suggests that local pituitary SST/ssts can contribute to the sexually dimorphic pattern of GH release. Fasting (48 h) reduced stomach sst2A/B and hypothalamic SST/sst2A expression in both sexes, whereas it caused a generalized downregulation of pituitary sst subtypes in male and of sst2A only in females. Thus, fasting can reduce SST sensitivity across tissues and SST input to the pituitary, thereby jointly contributing to enhance GH release. In SST-knockout mice, lack of SST differentially altered sst subtype expression levels in both sexes, supporting an important role for SST in sex-dependent control of GH axis. Evaluation of SST, IGF-I, and glucocorticoid effects on hypothalamic and pituitary cell cultures revealed that these hormones could directly account for alterations in sst2/5 expression in the physiological states examined. Taken together, these results indicate that changes in SST output and sensitivity can contribute critically to precisely define, in a tissue-dependent manner, the sex-specific metabolic regulation of the GH axis.     

Forecasting decadal changes in sea surface temperatures and coral bleaching within a Caribbean coral reef

Elevated sea surface temperature (SST) caused by global warming is one of the major threats to coral reefs. While increased SST has been shown to negatively affect the health of coral reefs by increasing rates of coral bleaching, how changes to atmospheric heating impact SST distributions, modified by local flow environments, has been less understood. This study aimed to simulate future water flow patterns and water surface heating in response to increased air temperature within a coral reef system in Bocas del Toro, Panama, located within the Caribbean Sea. Water flow and SST were modeled using the Delft3D-FLOW© computer simulation package. Locally measured physical parameters, including bathymetry, astronomic tidal forcing, and coral habitat distribution were input into the model and water flow, and SST was simulated over a four-month period under present day, as well as projected warming scenarios in 2020s, 2050s, and 2080s. Changes in SST, and hence the thermal stress to corals, were quantified by degree heating weeks. Results showed that present-day reported bleaching sites were consistent with localized regions of continuous high SST. Regions with highest SST were located within shallow coastal sites adjacent to the mainland or within the interior of the bay, and characterized by low currents with high water retention times. Under projected increases in SSTs, shallow reef areas in low flow regions were found to be hot spots for future bleaching.     

Long-Range Correlations of Global Sea Surface Temperature

Scaling behaviors of the global monthly sea surface temperature (SST) derived from 1870–2009 average monthly data sets of Hadley Centre Sea Ice and SST (HadISST) are investigated employing detrended fluctuation analysis (DFA). The global SST fluctuations are found to be strong positively long-range correlated at all pertinent time-intervals. The value of scaling exponent is larger in the tropics than those in the intermediate latitudes of the northern and southern hemispheres. DFA leads to the scaling exponent α = 0.87 over the globe (60°S~60°N), northern hemisphere (0°N~60°N), and southern hemisphere (0°S~60°S), α = 0.84 over the intermediate latitude of southern hemisphere (30°S~60°S), α = 0.81 over the intermediate latitude of northern hemisphere (30°N~60°N) and α = 0.90 over the tropics 30°S~30°N [fluctuation F(s) ~ s^α], which the fluctuations of monthly SST anomaly display long-term correlated behaviors. Furthermore, the larger the standard deviation is, the smaller long-range correlations (LRCs) of SST in the corresponding regions, especially in three distinct upwelling areas. After the standard deviation is taken into account, an index χ = α * σ is introduced to obtain the spatial distributions of χ. There exists an obvious change of global SST in central east and northern Pacific and the northwest Atlantic. This may be as a clue on predictability of climate and ocean variabilities.     

猕猴发育过程中肠肝组织生长抑素及其受体表达演变规律

探讨在猕猴发育过程中生长抑素(somatostatin,SST)及其受体在肠肝组织的演变规律。通过手术途径获得胚胎6月、新生2 d、新生45 d和成年猕猴的回肠、肝脏、门静脉和外周血等标本。应用放射免疫分析法测定各标本中的SST含量; 通过免疫组化方法观察SST在肠、肝组织内的分布;利用原位杂交检测SST受体2(somatostatin receptor 2,SSTR2)的表达。结果显示:(1)胚胎6月的猕猴,小肠内SST含量为(27．3±16．6)ng／mg蛋白;黏膜隐窝处SST呈弱阳性染色,肌层 SST染色阴性。在发育过程中,小肠内SST含量逐渐增加,成年期时达最高水平(120．1±35．3)ng／mg蛋白,较胚胎6月显著增加(P<0．01)。(2)成年小肠黏膜隐窝处及肌间神经丛SST呈强阳性染色。(3)胚胎6月,小肠粘膜上皮可见大量SSTR2 表达,成年时SSTR2表达下调,且主要定位于腺上皮隐窝处;胚胎及新生期肌层SSTR2染色阴性,成年时小肠肌间神经丛则可见阳性SSTR2染色。(4)肝脏在发育过程中SST及SSTR2含量逐渐降低;发育的各个时期,小肠组织的SST含量均明显高于肝脏组织含量,门静脉SST水平也始终高于外周血。总之,位于小肠黏膜隐窝处的SST和SSTR2随着发育逐渐增加,来自肠道的SST进入门静脉后迅速被降解。SST阳性的肠肌间神经丛仅在发育成熟后才出现。     

The herbal medicine sho-saiko-to induces nitric oxide synthase in rat hepatocytes

We have examined the effects of the herbal medicine sho-saiko-to (SST) on nitric oxide (NO) biosynthesis in rat hepatocytes by measuring the stable end-product nitrite and the mRNA of inducible NO synthase (iNOS). Interferon-γ (IFN) by itself failed to induce NO synthesis (IFN: 1-1,000 u/ml). SST also did not elicit NO synthesis at concentrations up to 300 μg/ml when administered alone, but dose-dependently induced NO production in the presence of IFN. Whereas SST or IFN induced barely detectable levels of iNOS mRNA when administered alone, a combination of SST and IFN markedly induced iNOS mRNA in the cells. SST also modestly increased NO synthesis caused by interleukin-1 or bacterial lipopolysaccharide as a single agent, or in combination with IFN. On the other hand, SST had no effects on the NO synthesis produced by iNOS which were already induced. Thus, we found that SST stimulates cultured hepatocytes to produce NO by inducing iNOS gene expression under appropriate conditions. The capability of SST to induce NO biosynthesis might be related to the therapeutic efficacy of SST on the liver diseases.     

Age, growth rate and season of recruitment of Pinna nobilis (L) in the Croatian Adriatic determined from Mg:Ca and Sr:Ca shell profiles

Stable oxygen isotope analyses of U-shaped spines removed at intervals along profiles of the outer shell surface of Pinna nobilis (L) were used to reconstruct sea surface temperature (SST) and validate the periodicity of adductor muscle scar rings on the inner shell surface. Elemental ratios (Mg:Ca and Sr:Ca) of spines, determined using Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES), were compared with the SST estimated from the stable oxygen isotopic composition of the shell deposited at the same time. The elemental ratios and the stable oxygen isotopic composition recorded in the shell were significantly correlated: Mg:Ca ratio=0.0002 (seawater temperature)+0.0095 (r²=0.445), Sr:Ca ratio=0.00005 (seawater temperature)+0.0014 (r²=0.887). The ratios in the spines were highest when the SST was warmest during July and August and were lowest between January and February when the SST was minimal.The positions of the first and second adductor muscle scar rings, unlike the later rings, are often difficult to discern, and in large shells they are obscured by nacre. Seasonal patterns in the elemental ratios were used to characterise the age in regions of the outer shell surface corresponding to the first two years of shell growth. A combination of both elemental ratios and muscle scar rings were used to estimate the age and hence the growth rate of P. nobilis from three locations in the Croatian Adriatic. Annual cycles of shell growth, inferred from the seasonal pattern in the element ratios, were used to determine the season of recruitment of fan mussels at several localities along the Croatian coastline. Pinnids generally settled during late autumn and winter although one shell from Mali Ston Bay settled during the summer. P. nobilis from Mali Ston Bay exhibited the fastest growth reaching a length of ∼60 cm and an age of 9 years, whereas those from Malo jezero grew the slowest attaining a length of ∼50 cm at 12 years of age.     

Somatostatin inhibits PDGF-stimulated Ras activation in human neuroblastoma cells.

The main physiological role of somatostatin (SST) is the control of hormone secretion. Recently, SST has been shown to exert antiproliferative effects on some human tumors via both direct and indirect mechanisms. We have previously found that in the human neuroblastoma cell line SY5Y the SST analogue lanreotide (BIM 23014) inhibited serum-stimulated cell proliferation and MAP kinase activity. Here, we examine the effect of SST on PDGF-induced Ras activation. We found that SST suppressed PDGF-induced Ras activation in a pertussis toxin (PTx)-independent and peroxovanadate-dependent manner. Ras-specific GTPase activating protein (GAP) activities were not altered by SST treatment. On the contrary, PDGF-induced PDGF receptor phosphorylation was decreased by SST in a PTx-independent, peroxovanadate-dependent manner, likely accounting for the SST-mediated inhibition of PDGF-induced Ras activation.     

Mercury in blood,hair, and feces from subsistence fish-eating riverines of the Madeira River Basin (Western Amazon)

BackgroundThe Madeira River (Amazon Basin) has been impacted by activities related to artisanal and small-scale gold mining (ASGM), deforestation and burning (for timber, agriculture, and hydroelectric dam projects). All these activities contribute to environmental mercury (Hg) release and cycling into the Amazon ecosystem and thus to changing lifestyles.MethodWe assessed exposure to total and MeHg in two small riverine communities of the Madeira River (Amazon): Lago Puruzinho (LP, n = 26 families) and São Sebastião do Tapurú (SST, n = 31 families). Samples of human hair (n = 137), blood (n = 39), and feces (n = 41) were collected from adults and children (0–15 years of age).ResultsIn women of childbearing age from LP village, the mean blood total-Hg (THg) (45.54 ± 24.76 μg.L⁻¹) and MeHg (10.79 ± 4.36 μg.L⁻¹) concentrations were significantly (p = 0.0024; p < 0.0001, respectively) higher than in women from SST village (THg: 25.32 ± 16.75 μg.L⁻¹; MeHg: 2.32 ± 1.56 μg.L⁻¹) village; the trend in hair-Hg persisted but was statistically significant (p < 0.0145) only for THg (LP, 11.34 ± 5.03 μg. g⁻¹; SST, 7.97 ± 3.51 μg. g⁻¹). In women, the median hair:blood ratio of total Hg was 269. In children, the mean hair THg concentrations were 6.07 ± 3.60 μg. g⁻¹ and 6.47 ± 4.16 μg. g⁻¹ in LP and SST; thus, not significantly different (p = 0.8006). There was a significant association (p < 0.001) between hair-Hg concentrations of mothers and their respective children. The excretion of Hg in feces of women (0.52 μg. g⁻¹ dw) was not significantly different from children (0.49 μg. g⁻¹ dw). The only statistically significant correlation between Hg in feces and in hair was found in children, (n = 16, r_s = 0.38, p = 0.005). Significant relationship was seen between the levels of THg in blood and hair of women from LP and SST. Based on hair-Hg concentrations, fish consumption rate ranged from 94.5 to 212.3 g.day⁻¹.ConclusionWomen and children excrete THg in feces in comparable concentrations. However, the mean fish consumption rate and blood MeHg are higher in the most remote villagers. Mother`s hair-Hg concentration is a good predictor of children’s hair-Hg.     

Oviducal sperm storage in turkeys: spatial distribution of sperm within the uterovaginal junction sperm-storage tubules.

The spatial distribution of sperm within the sperm storage tubules (SST) found in the uterovaginal junction (UVJ) of the turkey is not known. In this study, we inseminated sperm stained with a fluorescent dye (Hoechst 33342) to determine their distribution in SST in the ventral, dorsal, and lateral regions of the proximal, middle, and distal regions of the UVJ. There was no preferential filling in the ventral-dorsal axis of the UVJ. In contrast, preferential filling of the SST was observed in the middle section of the UVJ. Here the individual SST were clearly longer and more pleomorphic than the SST in the more proximal and distal aspects of the UVJ. While no information on the temporal aspect of SST filling by sperm could be gleaned, it is evident that the more morphologically developed SST either accept sperm more readily or store sperm more efficiently than SST elsewhere in the UVJ.