Development and isoproterenol-induced regulation of adrenoceptor binding in cultured rat neocortical explants is seen only with the beta-1, not with the beta-2 subtype

The presence and time-course of -adrenoceptor density in cultured explants of neocortex obtained from 6-day-old rat pups were investigated using a [¹²⁵I]ICYP binding assay. A delayed, but more pronounced, increase in the receptor expression was observed as compared to the situation previously described in vivo. These changes only occurred for the ₁-subtype of the receptor, whereas the ₂-subtype binding remained constant up to 3 weeks in vitro. The delay of ₁-adrenoceptor expression may be due to the incomplete presence of the proper maturational input, and the late enhancement of receptor expression to upregulation related to the absence in vitro of noradrenergic input. Decreased -adrenoceptor levels could be induced by chronic treatment of the -agonist isoproterenol (1 M) introduced either for 3 or 13 days. Again, changes in density were found only for the ₁-adrenoceptor binding sites. There is no reduction of receptor density following return to control conditions for 10 days after a 3-day treatment with isoproterenol, demonstrating the ability of this model to attain its final receptor density notwithstanding the developmental insult.Special issue dedicated to Dr. Robert Balázs     

gamma-aminobutyric acid increases the water accessibility of M3 membrane-spanning segment residues in gamma-aminobutyric acid type A receptors

gamma-Aminobutyric acid type A (GABA(A)) receptors are members of the ligand-gated ion channel gene superfamily. Using the substituted cysteine accessibility method, we investigated whether residues in the alpha(1)M3 membrane-spanning segment are water-accessible. Cysteine was substituted, one at a time, for each M3 residue from alpha(1)Ala(291) to alpha(1)Val(307). The ability of these mutants to react with the water-soluble, sulfhydryl-specific reagent pCMBS(-) was assayed electrophysiologically. Cysteines substituted for alpha(1)Ala(291) and alpha(1)Tyr(294) reacted with pCMBS(-) applied both in the presence and in the absence of GABA. Cysteines substituted for alpha(1)Phe(298), alpha(1)Ala(300), alpha(1)Leu(301), and alpha(1)Glu(303) only reacted with pCMBS(-) applied in the presence of GABA. We infer that the pCMBS(-) reactive residues are on the water-accessible surface of the protein and that GABA induces a conformational change that increases the water accessibility of the four M3 residues, possibly by inducing the formation of water-filled crevices that extend into the interior of the protein. Others have shown that mutations of alpha(1)Ala(291), a water-accessible residue, alter volatile anesthetic and ethanol potentiation of GABA-induced currents. Water-filled crevices penetrating into the interior of the membrane-spanning domain may allow anesthetics and alcohol to reach their binding sites and thus may have implications for the mechanisms of action of these agents.     

Immunohistochemical localization of irisin in mole rats (Spalax leucodon)

Irisin was first identified in skeletal muscle cells. It is an exercise protein that is secreted into the circulation; it causes conversion of white adipose tissue to brown adipose tissue. We investigated irisin immunoreactivity in mole rat (Spalax leucodon) tissues. We examined cerebellum, pituitary, heart, liver, pancreas, spleen, uterus, kidney and striated muscle in female adult mole rats. Tissues were processed, embedded in paraffin, sectioned at 5 μm and stained immunohistochemically for irisin. Irisin immunostaining was detected in the cytoplasm of stained cells; the cytoplasm of Purkinje cells was unstained. We found that irisin may be synthesized in many tissues. The function of locally synthesized irisin currently is unknown.     

Aspergillus terreus and its toxic metabolites as a food contaminant in some Egyptian Bakery products and grains

A. terreus isolates isolated from some bakery products, corn and rice were found to be able to produce territrems. 90% of theA. terreus isolated from bakery products were able to produce territrem A, with a mean of 0.09 ppm, while 80% ofA. terreus isolates produce territrem B with a mean of 0.24 ppm. On the other hand 31.8% of the isolates ofA. terreus from corn were able to produce territrem A with a mean of 0.44 ppm. ConcerningA. terreus isolates from rice, 66.7% were found to produce territrem A, with a mean of 5.28 ppm, and 77.8% of the isolates produced territrem B with a mean of 1.79 ppm.     

PSP94融合蛋白在大肠杆菌中的表达及其抗前列腺癌活性分析

在从成年人正常前列腺组织中获得人９４个氨基酸的前列腺分泌蛋白（ＰＳＰ９４）ｃＤＮＡ基础上,利用ＰＬ表达系统,实现了人ＰＳＰ９４成熟肽Ｎ 末端带有１９个外源氨基酸的融合蛋白在大肠杆菌中的表达。目的蛋白在细胞中主要以包涵体形式存在,表达量约占菌体总蛋白的３０％,分子量约为１６－５ｋＤ。表达产物在人前列腺癌细胞ＰＣ ３上活性分析表明,该融合蛋白能明显抑制前列腺癌细胞的生长。     

Skin Autofluorescence Based Decision Tree in Detection of Impaired Glucose Tolerance and Diabetes

Aim

Diabetes (DM) and impaired glucose tolerance (IGT) detection are conventionally based on glycemic criteria. Skin autofluorescence (SAF) is a noninvasive proxy of tissue accumulation of advanced glycation endproducts (AGE) which are considered to be a carrier of glycometabolic memory. We compared SAF and a SAF-based decision tree (SAF-DM) with fasting plasma glucose (FPG) and HbA1c, and additionally with the Finnish Diabetes Risk Score (FINDRISC) questionnaire±FPG for detection of oral glucose tolerance test (OGTT)- or HbA1c-defined IGT and diabetes in intermediate risk persons.

Methods

Participants had ≥1 metabolic syndrome criteria. They underwent an OGTT, HbA1c, SAF and FINDRISC, in adition to SAF-DM which includes SAF, age, BMI, and conditional questions on DM family history, antihypertensives, renal or cardiovascular disease events (CVE).

Results

218 persons, age 56 yr, 128M/90F, 97 with previous CVE, participated. With OGTT 28 had DM, 46 IGT, 41 impaired fasting glucose, 103 normal glucose tolerance. SAF alone revealed 23 false positives (FP), 34 false negatives (FN) (sensitivity (S) 68%; specificity (SP) 86%). With SAF-DM, FP were reduced to 18, FN to 16 (5 with DM) (S 82%; SP 89%). HbA1c scored 48 FP, 18 FN (S 80%; SP 75%). Using HbA1c-defined DM-IGT/suspicion ≥6%/42 mmol/mol, SAF-DM scored 33 FP, 24 FN (4 DM) (S76%; SP72%), FPG 29 FP, 41 FN (S71%; SP80%). FINDRISC≥10 points as detection of HbA1c-based diabetes/suspicion scored 79 FP, 23 FN (S 69%; SP 45%).

Conclusion

SAF-DM is superior to FPG and non-inferior to HbA1c to detect diabetes/IGT in intermediate-risk persons. SAF-DM’s value for diabetes/IGT screening is further supported by its established performance in predicting diabetic complications.     

Vasospasm is a significant factor in cyclosporine-induced neurotoxicity: Case report

Background

The aetiology of central nervous system lesions observed in cerebral cyclosporine neurotoxicity remains controversial.

Case presentation

We report a 48-year-old woman with a non-severe aplastic anaemia who presented with stroke-like episodes while on cyclosporine treatment.Transcranial Doppler ultrasound revealed severely elevated flow velocities in several cerebral vessels, consistent with vasospasm. Immediately after reducing the cyclosporine dose, the stroke-like episodes disappeared. Only after cyclosporine withdrawal the transcranial Doppler ultrasound abnormalities fully resolved.

Conclusions

This case demonstrates a significant role of vasospasm in the pathway of cyclosporine-induced neurotoxicity. Transcranial Doppler ultrasound is an effective tool for the diagnosis and follow-up of cyclosporine-induced vasospasm.

     

Characterisation of different morphological features of black tiger shrimp (Penaeus monodon) haemocytes using monoclonal antibodies

Monoclonal antibodies (mabs) specific for Penaeus monodon haemocytes were produced by immunising mice with membrane lysates of shrimp haemocytes. Four mabs (WSH 6, WSH 7, WSH 8 and WSH 16) were characterised using flow cytometry, light microscopy, laser scanning microscopy, electron microscopy and immunoprecipitation. WSH 6 recognised a carbohydrate determinant on an 85 kDa molecule. WSH 7, WSH 8 and WSH 16 recognised 50, 35 and 115 kDa molecules, respectively. For all mabs, differences in amount and intensity of the labelling were found when haemocytes were fixed immediately in 2% formaldehyde in Alsever's Solution (AS), compared with non-fixed haemocytes that were kept in AS (which reduced activation of the haemocytes) or in L15 cell culture medium. WSH 6 reacted with the cell membranes of all fixed haemocytes, while WSH 7 and WSH 16 reacted with the cell membranes of >80% of fixed haemocytes. The membrane labelling appeared to decrease when cells were kept in L15 medium. WSH 8 did not react with the haemocyte membranes. All mabs reacted with some granules, mainly present in the hyaline cells, when the haemocytes were immediately fixed. When non-fixed cells were kept in AS and in L15 medium, positive granules were also observed in semigranular and granular haemocytes as well as in the largest granules of a fourth cell type, that contains many granules of different size and electron density. Immunoreactive extracellular thread-like material could be observed in cells in L15 medium. The change in staining pattern was extreme for WSH 8, somewhat less for WSH 6 and WSH 7 and the lowest for WSH 16. Double labelling revealed that all mabs showed a different staining pattern on membranes as well as on granules. WSH 16 also showed labelling in cytoplasmic vesicles, as well as in haemolymph plasma on histological sections. The hypothesis is put forward that immunoreactive molecules recognised by these mabs, are related to haemocyte activation factors.     

Sources of fish in the ephemeral western iishana region of the Cuvelai–Etosha Basin in Angola and Namibia

The triangle between the Kavango and Kunene rivers is drained by the Cuvelai, an ephemeral and deltaic drainage system covering more than 100 000 km². In good rainfall years, the area becomes populated by fish communities dominated by five species migrating southward towards the endorheic Etosha Pan, the basin’s terminal sump. When water dries up, fish subsequently die-off and their sudden appearance in rainy years has captivated scientists for decades. The current study was prompted by hitherto untapped indigenous knowledge through narratives of opportunistic fish harvesting of migrating fish at temporary connections between the Kunene River and the Cuvelai- Etosha Basin. A reconnaissance fish survey in 2017 was complemented by digital satellite images and elevation data analyses. Results support the presence of at least three major ephemeral fish migration routes. The dominant fish genera migrating upstream in Kunene tributaries comprise Enteromius, Oreochromis and Clarias, all eurytopic and known to undertake upstream, lateral and downstream migrations on floodplains. Although other notable fish refugia in the Cuvelai–Etosha Basin are yet to be identified, there is a necessity for the protection and management of these migration routes in tandem with studies on the nature and extent of this inter-basin fish migration under climate change and variability.