Distribution of FMRFamide-like immunoreactivity in the brain and neurohypophysis of the lamprey,Lampetra japonica

Summary Distribution of molluscan cardio-excitatory tetrapeptide Phe—Met—Arg—Phe—NH₂ (FMRFamide) was determined by means of immunohistochemistry in the brain and neurohypophysis of the lamprey, Lampetra japonica. Many FMRFamide-like immunoreactive neurons were found in the periventricular nuclear region and in a region near the mammillary recess. Neurons situated in the former region were larger. The immunoreactive cell groups were shown to be located at sites differing from those of the AF-positive cell groups. The fibers of immunoreactive neurons extended in all directions within the brain and towards the spinal cord, some reaching the third ventricle and capillaries. Thus, FMRFamide-like immunoreactive peptides appear to function as neurotransmitters or neuromodulators and possibly also as neurohormones. FMRFamide-like immunoreactive material was rarely observed in the posterior neurohypophysis (neural lobe), but was noted to be present to a limited extent in the caudal part of the anterior neurohypophysis (median eminence). It would thus follow that FMRFamide-like immunoreactive neurons may not necessarily be related to the hypothalamo-neural lobe system, but may possibly be associated with the hypothalamoadenohypophysial system. The pineal body showed no FMRFamide-like immunoreactivity.     

Hemodynamic effects of atrial natriuretic hormone

The atrial natriuretic hormone (ANH) alters cardiovascular function independent of changes in body fluid volume. Most investigators agree that ANH decreases mean arterial pressure (MAP). However, although some investigators have observed a decrease in total peripheral resistance in association with the decrease in MAP, a more frequent observation has been decreased cardiac output (CO). The mechanism whereby ANH decreases CO is unknown, but does not appear to be the result of direct myocardial depression, reductions in intravascular or cardiopulmonary volumes, or venodilation. Alterations in skeletal muscle and splanchnic blood flow have been reported by some but not all investigators. Although increases in renal blood flow have been reported, they are transitory and have not been consistently observed by all researchers. The cardiovascular effects of ANH appear to be influenced not only by the dose, but also by the cardiovascular control mechanisms that operate at the time of ANH administration. Non-renin-dependent hypertensive models exhibit a decrease in MAP associated with decreased CO, whereas in renin-dependent animals this hypotension is associated with a decrease in total peripheral resistance.     

Effects of body and head positions on bilateral difference in tympanic temperatures

We have examined the nonparallel changes in tampanic membrane temperatures (T _ty) from the two ears in response to various changes in body and head positions. Upon assuming a lateral recumbent position, the T _ty on the lower side increased while that on the upper side decreased. Pressure application over a wide area of the lateral chest only caused inconsistent and obscure asymmetric changes in T _ty. A lateral flexion of the head with the subject sitting upright and a rotation of the head to the side in a supine position induced an increase in the T _ty on the lower side compared to that on the upper side. The temperature and blood flow of the forehead often decreased on the lower side and increased on the upper side, although such responses were not always concomitant with the asymmetric changes in T _ty. A dorsal flexion of the head with the subject in a reclining position caused a slight increase in the T _ty, whereas raising the head upright induced a slight decrease in them. Two additional experiments were carried out with single photon emission computed tomography using ^99mTc-hexamethylpropyleneamine oxime as tracer, and a slight, relative decrease in counts was noted in the right hemisphere during rotation of the head to the right. These results would strongly suggest that unilateral increases and decreases in T _ty could have been caused by one-sided decreases and increases, respectively, in blood flow to the brain and/or the tympanic membrane, induced by a vasomotor reflex involving vestibular stimulation.     

Dynamic sweating response of man to infrared irradiation in various spectral regions

In an attempt to detect differences in the thermal effect of infrared irradiation of different wavelengths, transient sweating response to infrared irradiation in various spectral regions was examined. In Series 1, the ventral or dorsal surface of the nude subject was irradiated repetitively for a period of 4 min (2 min on, 2 min off) by each of three kinds of infrared heaters with main emissivity in near-infrared (NIR; 0.7–2.8 m), intermediate-infrared (MIR; 1.5–5.8 m), and far-infrared (FIR; 2.8–25 m) regions. The sweating response on a non-irradiated area tended to be the greatest with MIR, while the magnitude of the sweating response on the irradiated area showed no consistent differences among various wavelengths. The results infer that MIR stimulated cutaneous thomoreceptors most effectively, while its direct effect on local sweat gland activity was minimal. In Series 2, the effects of 9–12 min irradiations in more restricted ranges of wavelength were compared by the combination of the three kinds of heaters with filters (translucent to wavelength ranges of 1.3–2.7, 2.7–3.5, 3.6–8.0 m, respectively). The sweating response on a remote area was predominantly greater with the range of 2.7–3.5 m than with the other wavelength ranges, while the local effect on sweating was minimal with this range. The results of Series 2 reinforce those of Series 1, indicating that the degree of stimulation of cutaneous thermoreceptors and of direct thermal effect on sweat gland activity differ with spectral regions incident on the skin, thus affecting local and remote effects on the sweating response.     

Preferred ambient temperature for old and young men in summer and winter

To investigate the effects of age on thermal sensitivity, preferred ambient temperature (T _pref) was compared between old (71–76 years) and young (21–30 years) groups, each consisting of six male subjects in summer and winter. The air temperature (T _a) was set at either 20° C or 40° C at commencement. The subject was directed to adjust theT _a for 45 min by manipulating a remote control switch to the level at which he felt most comfortable. In the older group, theT _pref was significantly lower in trials starting at 20° C than that starting at 40° C in summer. The fluctuation ofT _pref (temperature difference between maximum and minimumT _a during the last 10 min) was significantly wider in the older group in both summer and winter. Repetition of the same experiment on each subject showed a poorer reproducibility ofT _pref in the older group than in the younger group in summer. Tympanic and esophageal temperatures of the older group kept falling throughout the trial starting at 20° C in summer. These results suggest that thermal sensitivity is decreased with advancing age and that thermal perception in the elderly, especially to cold, is less sensitive in summer.     

Parturition in a free-ranging Japanese monkey (Macaca fuscata)

Parturition behavior of a multiparous female and her interactions with group members throughout the birth process were recorded for a free-ranging Japanese monkey (Macaca fuscata). The female showed evidence of 18 contractions during the 35 min prior to delivery, with a mean duration and a mean intercontraction interval of 30 sec and 96 sec, respectively. These values were similar to those in individually caged Japanese monkeys. Some adult females remained in proximity to the female who was giving birth during the prepartum phase, and her 2-year-old daughter watched the delivery of the infant. Even during the prepartum phase the female moved in order to keep up with the group which traveled from the feeding site to a sleeping site in the forest.     

Hydrolysis of fourteen native dextrans by arthrobacter isomaltodextranase and correlation with dextran structure

The isomaltodextranase (EC 3.2.1.94) from Arthrobacter globiformis T6 hydrolysed thirteen dextrans to various extents (11?64% after 13 days) at initially large but gradually decreasing rates. Dextran B-1355 fraction S was, unlike the other dextrans, hydrolysed by the dextranase initially at the lowest rate among the dextrans used, but the rate was maintained for a long period with little decrease, so that the hydrolysis reached as high as 85% after 13 days. Paper chromatography of these dextran digests revealed that this dextranase produces in addition to isomaltose, one or two trisaccharides [isomaltose residues substituted by (1 →2)-, (1→3)-, or (1→4)-α-D-glucopyranosyl groups at the non-reducing D-glucopyranosyl residues] from every dextran used. It is evident that the non-(1→6)-linkages of these trisaccharide products constitute the “anomalous” linkages of the corresponding dextrans. The relative amounts of these trisaccharide products appear to indicate the approxima te relative amounts of a particular linkage among the dextrans, or the relative amounts of two kinds of linkages of each dextran. The kinds and the relative amounts of “anomalous” linkages of some dextrans were established on the basis of the trisaccharides produced by isomaltodextranase.     

Effect of pinocembrin isolated from Alpinia zerumbet on osteoblast differentiation

Cytotechnology - Bone mass is regulated by osteoblast-mediated bone formation and osteoclast-mediated bone resorption. Osteoporosis is a bone metabolism disorder in which bone mass decreases due to...     

Optineurin suppression causes neuronal cell death via NF‐κB pathway

Mutations in more than 10 genes are reported to cause familial amyotrophic lateral sclerosis (ALS). Among these genes, optineurin (OPTN) is virtually the only gene that is considered to cause classical ALS by a loss‐of‐function mutation. Wild‐type optineurin (OPTN^WT) suppresses nuclear factor‐kappa B (NF‐κB) activity, but the ALS‐causing mutant OPTN is unable to suppress NF‐κB activity. Therefore, we knocked down OPTN in neuronal cells and examined the resulting NF‐κB activity and phenotype. First, we confirmed the loss of the endogenous OPTN expression after siRNA treatment and found that NF‐κB activity was increased in OPTN‐knockdown cells. Next, we found that OPTN knockdown caused neuronal cell death. Then, overexpression of OPTN^WT or OPTN^E50K with intact NF‐κB‐suppressive activity, but not overexpression of ALS‐related OPTN mutants, suppressed the neuronal death induced by OPTN knockdown. This neuronal cell death was inhibited by withaferin A, which selectively inhibits NF‐κB activation. Lastly, involvement of the mitochondrial proapoptotic pathway was suggested for neuronal death induced by OPTN knockdown. Taken together, these results indicate that inappropriate NF‐κB activation is the pathogenic mechanism underlying OPTN mutation‐related ALS.

     

Substrate specificity and gene expression of two Penicillium chrysogenum α-l-arabinofuranosidases (AFQ1 and AFS1) belonging to glycoside hydrolase families 51 and 54

We previously isolated two α-l-arabinofuranosidases (ABFs), termed AFQ1 and AFS1, from the culture filtrate of Penicillium chrysogenum 31B. afq1 and afs1 complementary DNAs encoding AFQ1 and AFS1 were isolated by in vitro cloning. The deduced amino acid sequences of AFQ1 and AFS1 are highly similar to those of Penicillium purpurogenum ABF 2 and ABF 1, respectively, which belong to glycoside hydrolase (GH) families 51 and 54, respectively. Pfam analysis revealed an “Alpha-L-AF_C” domain in AFQ1 and “ArabFuran-catal” and “AbfB” domains in AFS1. Semi-quantitative RT-PCR analysis indicated that the afq1 gene was constitutively expressed in P. chrysogenum 31B at a low level, although the expression was slightly induced with arabinose, arabinitol, arabinan, and arabinoxylan. In contrast, expression of the afs1 gene was strongly expressed by the above four carbohydrates and less strongly induced by galactan. Recombinant enzymes (rAFQ1 and rAFS1) expressed in Escherichia coli were active against both p-nitrophenyl α-l-arabinofuranoside and polysaccharides with different specificities. ¹H-NMR analysis revealed that rAFS1 degraded arabinofuranosyl side chains that were both singly and doubly linked to the backbones of arabinoxylan and l-arabinan. On the other hand, rAFQ1 preferentially released arabinose linked to C-3 of single-substituted xylose or arabinose residues in the two polysaccharides.