Insulin effects in clarias batrachus L.: a combined biochemical and anatomical study

The effect of mammalian insulin was studied in a freshwater fish, Clarias batrachus, at both high and low ambient temperatures. The hormone produced a significant but delayed, yet recoverable, lowering of blood glucose, a concurrent decrease in liver glycogen, and an increase in the glycogen content of muscles. The decrease in brain glycogen occurred during advanced hypoglycemia. Hypoglycemic seizures developed intermittently in most of the fishes whose plasma glucose and brain glycogen levels had been considerably depleted. Necrobiotic changes in the pancreatic islets, including degranulation and atrophy, and necrosis of B cells, were seen in the treated fish. In some cases damage to A cells and the acinar tissue was also observed. With the restitution of normal glucose and glycogen values, the islet cells also seemed to have recuperated. Changes in glycemia, glycogen, and the islets were more pronounced in the fishes held at 24 degrees C than in those at 10 degrees C, indicating that the ambient temperature plays an important role in blood glucose homeostasis as well as insulin.     

Recurrent Bacteremia Caused by a “Flexispira”-Like Organism in a Patient with X-Linked (Bruton’s) Agammaglobulinemia

Helicobacter spp., except for Helicobacter cinaedi, have only rarely been reported in cases of septicemia. A patient with X-linked (Bruton's) agammaglobulinemia was found to have persistent sepsis with a Helicobacter-like organism despite multiple courses of antibiotics. His periods of sepsis were associated with leg swelling thought to be consistent with cellulitis. The organism was fastidious and required a microaerophilic environment containing H(2) for growth. Optimal growth was observed at 35 to 37 degrees C on sheep blood, CDC anaerobe, and Bordet-Gengou agars. Serial subcultures every 4 to 5 days were required to maintain viability. The organism was strongly urease positive and showed highest relatedness to Helicobacter-like organisms with the vernacular name "Flexispira rappini" by 16S rRNA gene sequence analysis. Genomic DNA hybridization studies, however, found 24 to 37% relatedness to "F. rappini" and even less to other Helicobacter spp. Although the organism phenotypically resembles "Flexispira" and Helicobacter, it is thought to represent a new taxon. The patient's infection was eventually cleared with a prolonged (5-month) course of intravenous imipenem and gentamicin.     

Serologic analysis of white-tailed deer sera for antibodies to Borrelia burgdorferi by enzyme-linked immunosorbent assay and western immunoblotting.

White-tailed deer serum samples were collected in the Minneapolis-St. Paul, Minn., metropolitan area during the fall and winter months from 1989 to 1992 and analyzed for antibodies to Borrelia burgdorferi, the etiologic agent of Lyme borreliosis. Ninety-eight percent of the serum samples were collected from regions where currently the vector tick, Ixodes dammini, is nonexistent. Antibodies to B. burgdorferi were detected in 2.2% of 508 samples by enzyme-linked immunosorbent assay, and their presence was confirmed by Western immunoblot analysis. Western immunoblotting yielded mean numbers of reactive bands of 0.1 and 6.0 for samples that were negative and positive for antibodies by enzyme-linked immunosorbent assay, respectively. The molecular weights of the antigens in many of the reactive bands from positive samples were similar to the molecular weights of antigens reactive with samples from humans with Lyme borreliosis. An antibody response to the major outer surface proteins A and B was not detected. Serologic analysis of deer sera may provide a valuable method for surveillance programs designed to monitor the spread of B. burgdorferi in nature.     

Microbiology subsystem of a total, dedicated laboratory computer system.

The computer system used by the Microbiology Service of the Clinical Pathology Department, Clinical Center, National Institutes of Health is discussed. This microbiology subsystem is a part of a dedicated on-line laboratory computer system used by the entire department. The laboratory computer is connected on-line to a hospital computer which provides patient admission, transfer, and discharge data. Mark sense worksheets and cathode ray tube terminals are used for result entry and correction. Cumulative patient reports are printed. Results for both active and completed accessions can be easily retrieved on cathode ray terminals in the laboratory. All laboratory data are archived on magnetic tape from which a research data base and microfiched laboratory records are generated. The manner in which the system is integrated in the routine operation of the microbiology laboratory is emphasized. In addition, some of the costs, benefits, liabilities, and pitfalls associated with the introduction of the computer in the laboratory are reviewed. Finally, we have presented our concept of some of the future enhancements to our present system and some of the directions in which any future microbiology system might develop.     

AIDS-associated Kaposi''s sarcoma-derived cells in long-term culture express and synthesize smooth muscle alpha-actin.

Spindle-shaped cells from Kaposi's sarcoma lesions (AIDS-KS cells) were cultured for long periods in the presence of conditioned medium from activated CD4-positive T cells (HTLV-II infected transformed nonvirus producer) and characterized under in vitro conditions. To investigate a possible vascular origin, AIDS-KS cells were analyzed for the presence of smooth muscle alpha-actin, a differentiation marker for vascular smooth muscle cells. Immunofluorescence studies using a monoclonal antibody for smooth muscle alpha-actin demonstrated positive staining of the AIDS-KS cells (KS-3 and KS-4) but not by endothelial cells or fibroblasts. Northern blot analysis using an oligonucleotide probe unique for human smooth muscle alpha-actin indicated the expression of this gene by AIDS-KS cells. Similar analysis of biopsies from the KS lesion showed that in addition to the staining of smooth muscle cells associated with the blood vessels, the tumor-related spindle cells also stained positively. These cells were also analyzed for the expression of different growth factor genes. The platelet-derived growth factor (PDGF) A-chain gene was expressed at a moderate level. The insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-2 (IGF-2) genes were not overexpressed in relation to control cells. These data suggest that the analyzed AIDS-KS cells may be smooth muscle-like cells and therefore of vascular origin. Based on these results as well as previous reports, we speculate that cells of the immune system may regulate growth of cells in the vascular wall by a novel pathway.     

Construction and expression of recombinant plasmids encoding type 1 or D-mannose-resistant pili from a urinary tract infection Escherichia coli isolate.

Isolates of Escherichia coli from human urinary tract infections frequently express adherence properties found less often among normal intestinal isolates. These properties include adherence to human uroepithelial cells and primary monkey kidney cells, as well as D-mannose-resistant hemagglutination of human erythrocytes, and they are mediated by a pilus type different from type 1. The genes encoding this pilus type (pyelonephritis-associated pili, pap) and those encoding type 1 pili have been cloned from a urinary tract infection isolate of E. coli and transferred to an E. coli K-12 derivative. The recombinant plasmids were found to express functional pili and to endow the new host with all of the adherence properties of the urinary tract infection isolate. Both pilus types were found to be genetically distinct, and unlike the adherence genes from bovine, porcine, and human diarrheal isolates, both were found to be chromosomally encoded.     

The infrapyloric artery and cephalic pancreatoduodenectomy with pylorus preservation: preliminary study

Summary Cephalic pancreatoduodenectomy (CPD) with pylorus preservation has been suggested to improve the functional and nutritional result of surgery. At operation, the first two centimeters of the duodenum are preserved, the vascular arch of the lesser gastric curvature is saved and the right gastroepiploic artery is resected at its origin. The aim of this study on 15 fresh cadavers was to determine the origin of the vascularization of the remaining duodenum and also the possibilities of preserving an optimal vascularization after CPD and pylorus preservation. All of the arteries supplying the remaining duodenum and arising either from the right gastric artery or the right gastroepiploic artery were identified. The distances between the origin of the infrapyloric artery and the termination of the gastroduodenal artery on the cranial and ventral pancreaticoduodenal artery and the left gastroepiploic artery were measured. At CPD with pylorus preservation, the study demonstrated that: 1) the cranial side of the remaining duodenum remains vascularized in 80% of the cases by one or two supraduodenal branches coming from the right gastric artery; 2) ligation of the right gastroepiploic artery eliminates all vascular supply to the caudal side of the remaining duodenum in almost half of the cases; 3) in these cases, the dissection of the bifurcation of the gastroduodenal artery and the vascular section beyond the origin of the infrapyloric artery allowed a direct vascular supply to the remaining duodenum to be preserved.This work was presented at the French Section of the European Association of Clinical Anatomy meeting, Bobigny, France, 1992     

Potential target sites in peripheral tissues for excitatory neurotransmission and excitotoxicity

Glutamate receptors (GluRs) are ubiquitously present in the central nervous system (CNS) as the major mediators of excitatory neurotransmission and excitotoxicity. Neural injury associated with trauma, stroke, epilepsy, and many neurodegenerative diseases such as Alzheimer's, Huntington's, and Parkinson's diseases and amyotrophic lateral sclerosis may be mediated by excessive activation of GluRs. Neurotoxicity associated with excitatory amino acids encountered in food, such as domoic acid and monosodium glutamate, has also been linked to GluRs. Less is known about GluRs outside the CNS. Recent observations suggest that several subtypes of GluRs are widely distributed in peripheral tissues. Using immunochemical and molecular techniques, the presence of GluR subtypes was demonstrated in the rat and monkey heart, with preferential distribution within the conducting system, nerve terminals, and cardiac ganglia. GluR subtypes NMDAR 1, GluR 2/3, and mGluR 2/3 are also present in kidney, liver, lung, spleen, and testis. Further investigations are needed to assess the role of these receptors in peripheral tissues and their importance in the toxicity of excitatory compounds. Therefore, food safety assessment and neurobiotechnology focusing on drugs designed to interact with GluRs should consider these tissues as potential target/effector sites.