FMRFamide-like material in the earwig, Euborellia annulipes, and its functional significance.

The neurosecretory system of the earwig, Euborellia annulipes, contained material similar to that of FMRFamide, as shown by immunocytochemistry. Within the brain were two pairs of darkly staining perikarya in the medial protocerebrum, and up to four pairs of immunoreactive cells in the lateral protocerebrum. The corpora allata appeared immunoreactive in 10-day females, but not in 2-day-old adults. Additionally, immunoreactive material was detected in midgut endocrine cells of both 2- and 10-day-old females. FMRFamide at 1 to 100 nM did not inhibit juvenile hormone production by earwig corpora allata in vitro. This was true of glands of low activity from 2-day cat food-fed or starved virgin females, 10-day starved females, and those of relatively high activity from 10-day-old, cat food-fed females. In contrast, FMRFamide at 50 and 100 (but not at 1) nM stimulated gut motility in vitro in distended guts from 2-day fed females. Preparations from starved females and those from 10-day fed females (in which feeding behavior is on the decline) did not respond to exogenous FMRFamide with enhanced rates of contraction. Lastly, preparations from females starved for 7 days and subsequently fed for 3 days responded to 10 nM FMRFamide with increases in gut motility.     

Sequence and expression of the gene for N10-formyltetrahydrofolate synthetase from Clostridium cylindrosporum.

Sau3 A and Hind III restriction fragments of Clostridium cylindrosporum genomic DNA were used to isolate clones containing 80% of the N10-H4folate synthetase gene in a 5' fragment and the remaining 20% of the gene in the 3' fragment. These fragments were joined at a common SnaB I restriction site and expressed in Escherichia coli at a level equivalent to what is normally found in C. cylindrosporum. Sequence comparisons show a large degree of homology with genes from two other clostridial species, including a thermophile. Certain conserved sequences found in the three clostridial proteins and in the N10-H4folate synthetase portion of eukaryotic C1-H4folate synthases may represent consensus sequences for nucleotide and H4folate binding.     

1071. Corydalis hamata Franch: Papaveraceae.

Corydalis hamata Franch. is described and illustrated. Variation within the species and relationships with related species are discussed. Corydalis pseudohamata Fedde is reinstated as a species.     

The Gly/Arg-rich (GAR) domain of Xenopus nucleolin facilitates in vitro nucleic acid binding and in vivo nucleolar localization.

Epitope-tagged Xenopus nucleolin was expressed in Escherichia coli cells and in Xenopus oocytes either as a full-length wild-type protein or as a truncation that lacked the distinctive carboxy glycine/arginine-rich (GAR) domain. Both full-length and truncated versions of nucleolin were tagged at their amino termini with five tandem human c-myc epitopes. Whether produced in E. coli or in Xenopus, epitope-tagged full-length nucleolin bound nucleic acid probes in in vitro filter binding assays. Conversely, the E. coli-expressed GAR truncation failed to bind the nucleic acid probes, whereas the Xenopus-expressed truncation maintained slight binding activity. Indirect immunofluorescence staining showed that myc-tagged full-length nucleolin properly localized to the dense fibrillar regions within the multiple nucleoli of Xenopus oocyte nuclei. The epitope-tagged GAR truncation also translocated to the oocyte nuclei, but it failed to efficiently localize to the nucleoli. Our results show that the carboxy GAR domain must be present for nucleolin to efficiently bind nucleic acids in vitro and to associate with nucleoli in vivo.     

Vascular effects of acetylcholine, catecholamines and detergents on isolated perfused gills of pink salmon, Oncorhynchus gorbuscha coho salmon, O. kisutch and chum salmon, O. keta

Acetylcholine caused vasoconstriction whilst adrenaline and isoprenaline caused vasodilation in isolated perfused Pacific salmon gills. The detergent LAS produced concentration dependent vasodilation when present in the perfusate in concentrations of 0.6 to 3 mg 1⁻¹. The effect of LAS was partly blocked by propranalol suggesting the involvement of β-adrenergic receptors. The maximum responses obtained with acetylcholine, adrenaline or LAS were all much greater in sea water or pre-spawning freshwater fish than in spawning fish.     

Alcohol and acetaldehyde metabolism in Caucasians,Chinese and Amerinds.

Ethanol (0.4 to 0.8 g/kg in 30 minutes) was given by mouth to 102 healthy young volunteers (37 Caucasian men, 21 Caucasian women, 20 Chinese men and 24 Ojibwa men). Venous blood concentrations of ethanol and acetaldehyde 60, 90, 120 and 150 minutes after the end of drinking were measured by gas chromatography. The calculated rates of ethanol metabolism in the Caucasian men and women did not differ, but the overall group means for subgroups of Caucasians (103.6 mg/kg-h), Chinese (136.6 mg/kg-h) and Ojibwa (182.7 mg/kg-h) with decreasing postabsorption values differed significantly from each other. Mean acetaldehyde values paralleled the rates of ethanol metabolism: Ojibwa, 14.6 mug/ml; Chinese, 10.0 mug/ml; and Caucasians, 9.4 mug/ml. The high rate of ethanol metabolism in Amerind subjects differs from previous findings. Habitual level of alcohol consumption, proportion of body fat and genetic factors appear to account for most of the group differences.     

The Emerging Role of Copeptin

Direct measurement of the nonapeptide vasopressin has been limited by analyte instability ex vivo and in vivo rapid degradation, low serum concentrations requiring a sensitive assay and inherent secretory pulsatility. Copeptin is a 39 amino acid glycopeptide cleavage product of vasopressin synthesis with high stability, providing a marker of vasopressin secretion. Copeptin measurement has applications in diagnosis of diabetes insipidus and other diseases with altered vasopressin secretion. This review summarises our current understanding of serum copeptin measurement in diabetes insipidus and possible future applications of copeptin assays. As vasopressin is a stress hormone, there is emerging evidence on the use of copeptin for diagnosis and prognostication of disorders such as syndrome of inappropriate anti-diuretic hormone secretion, diabetes mellitus, critical illness, stroke, cardiovascular disease, respiratory disease, renal disease and thermal stress. Copeptin concentration measurement is likely to improve the diagnostic reliability of diabetes insipidus and, as a marker of stress, may have diagnostic or prognostic utility in specific clinical circumstances. Further studies are needed to determine if goal-directed therapy using plasma copeptin concentrations may improve patient outcomes.