Neuropeptides: Animal behaviour and human psychopathology

Summary Animal studies have demonstrated that neuropeptides modulate nervous system functions. It has been postulated that disturbances in neuropeptide systems may be aetiological factors in psychiatric and neurological disorders. Neuropeptides related to ACTH/MSH, including ORG 2766, increase motivation and attention and facilitate recovery processes after nerve damage. These peptides may be effective during the early stage of dementia. Vasopressin and related peptides improve memory processes in animals and humans. In addition, these peptides influence social behaviour, mood and addictive behaviour. The non-opioid -type endorphins have neurolepticlike activities in animals and antipsychotic effects in a category of schizophrenic patients. Peptides related to CCK have also been found to be effective in these patients. Some neuropeptides, e.g. TRH and PLG, have been reported to exert antidepressant effects. Further research may eventually produce neuropeptides with therapeutic action in psychiatric and neurological diseases.Parts of this article were presented on the occasion of the inauguration ceremony of the Department of Psychiatry of the University of Mainz on April 2 and 3, 1987     

Infection of catheterised patients: bacterial colonisation of encrusted Foley catheters shown by scanning electron microscopy

Summary The surfaces of 32 encrusted urinary catheters were examined by scanning electron microscopy to investigate the association of bacteria with the encrusting deposits. Deposits consisted of struvite crystals surrounded by aggregates of very small crystallites of hydroxyapatite. Underneath these minerals there was a layer of closely packed bacteria. Impressions of bacteria were also observed in hydroxyapatite. Crystals were often engulfed by the bacterial layer, which thus appeared to bind the crystals to each other and to the catheter surface. This thick layer of bacteria associated with crystals may protect both the bacteria from antibiotics and the crystals from acidic bladder washout solutions intended to dissolve them. Furthermore, the existence of this sessile population explains why urease-producing bacteria are not invariably detected in the urine of patients with encrusted catheters. The observation of this bacterial layer (or biofilm) by scanning electron microscopy provided direct evidence for infection being implicated in catheter encrustation.     

Effect of moderate exercise on salivary immunoglobulin A and infection risk in humans

The incidence of upper respiratory tract infections (URTI) and salivary immunoglobulin A concentrations [IgA_s] of nine individuals were examined during 12 weeks of moderate exercise training, and compared to ten sedentary controls. Changes in maximal oxygen uptake were assessed at initial, mid-point and final evaluations (T1–3), while changes in [IgA_s] and salivary immunoglobulin concentration-salivary albumin concentration ratio ([IgA_s]:[Alb_s]) were monitored at T1 and T3. During the 12 week period, symptoms of URTI were self-recorded daily. During the period of training the level of fitness significantly increased (P<0.05) in the exercise group. The number of days recording symptoms of influenza, but not of cold, and total light URTI symptoms was significantly reduced in the exercise group during the last weeks of training. A significant increase in [IgA_s] and in [IgA_s]:[Alb_s] was found in the exercise group after training. Both [IgA_s] and [IgA_s]:[Alb_s] were significantly related to the number of days showing symptoms of influenza (P<0.01) and the total number of days of sickness (P<0.05). These data provide quantitative support for the belief that regular, moderate exercise results in an increased [IgA_s] at rest and [IgA_s]:[Alb_s], which may contribute to a decreased risk of infection. Electronic Publication     

Temperature stabilizing effect of tocopherol on rhodopsin in the pressure of fatty acids studied by differential scanning calorimetry

Institute of Cytology, Academy of Sciences of the USSR. I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Institute of Physiology, Bulgarian Academy of Sciences, Sofia. (Presented by Academician of the Academy of Medical Sciences of the USSR Yu. A. Vladimirov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 108, No. 8, pp. 160–171, August, 1989.     

Serum 27E10 antigen: a new potential marker for staging HIV disease.

MRP8 and MRP14 are myeloic related proteins expressed by most circulating and emigrated neutrophils and monocytes. Their composite molecule MRP8/14 (27E10 antigen) was shown to exhibit striking antimicrobial properties. The aim of the present study was to assess the value of MRPs as markers for detection of the different stages of HIV infection (Centres for Disease Control and Prevention, 1993). By employing the ELISA technique we measured serum concentrations of these proteins in samples from 122 HIV patients at the various stages of disease, and the results were compared with those for healthy controls. Serum levels of the heterodimeric molecule 27E10 were significantly increased (P < 0.001) in patients with CDC stages II and III, with the highest levels being in patients with stage III and acute ongoing opportunistic infections. For the single component MRP14, significantly raised levels (P < 0.05) were only found in HIV stage III individuals with acute clinical events. Similar associations were not found for MRP8 alone. Increase was not related to CD4+ cell count. There was a significant correlation between 27E10 antigen serum concentrations and levels of neopterin in patients with HIV stages II and III without acute concurrent illness. Patients being treated with Zidovudine showed no statistically significant variation in levels of 27E10 and its single components MRP8 and MRP14 compared with untreated patients. These findings suggest that elevation of MRP14 levels occurs in HIV+ individuals at later stages post-HIV infection, after the onset of opportunistic infections. 27E10 antigen is concluded to be a potential marker for the different stages of HIV disease.     

Role of tight junctions of polarized epithelial MDCK cells in the replication of herpes simplex virus type 1

Before completion of polarization, Madin-Darby canine kidney (MDCK) cells showed high infectivity and progeny production of herpes simplex virus type 1 infection. After polarization or formation of tight junctions, the infectivity and virus replication in MDCK cells was restricted significantly. The disruption of tight junctions by depletion of Ca²⁺ resulted in increasing virus infectivity and productivity. Mechanical disruption of tight junctions by scratching the cell monolayers with injection needle allowed markedly the replication of HSV-I in the cells aligned along the injured area. In polarized MDCK cells the progeny were released preferentially from the apical surface of the cells. These data suggest that because polarized MDCK cells mimic the epithelial cell layers, this cell line is helpful for determining the factors which regulate viral transmission in the human body. © Wiley-Liss, Inc.     

Visceral leishmaniasis in the acquired immunodeficiency syndrome: Report of two cases

Core biopsies of the bone marrow are indispensable in the evaluation of fever of unknown etiology in human immunodeficiency virus-positive patients. We report two patients in whom visceral leishmaniasis was diagnosed based on the typical morphology, staining characteristics, and ultrastructure of the organisms.     

Virus-inhibiting surgical glove to reduce the risk of infection by enveloped viruses

Needle puncture and other accidents that occur during surgery and other procedures may lead to viral infections of medical personnel, notably by hepatitis C (HCV) and human immunodeficiency virus (HIV), now that hepatitis B can be prevented by vaccination. A new surgical glove called G-VIR, which contains a disinfecting agent for enveloped viruses, has been developed. Herpes simplex type 1 (HSV) was used as a standard enveloped virus in both in vitro and in vivo tests of the virucidal capacity of the glove. Bovine viral diarrhea virus (BVDV) and feline immunodeficiency virus (FIV) were used as models for HCV and HIV, respectively. For in vitro study, a contaminated needle was passed through a glove and residual virus was titrated; for in vivo studies, animals were stuck with a contaminated needle through a glove. Despite variation in virus enumeration inherent in the puncture technique, statistical evaluation showed that infection was reproducibly and substantially reduced by passage through the virucidal layer. For BVDV, the amount of virus passing through the virucidal glove was reduced in 82% of pairwise comparisons with control gloves that lacked the virucidal agent; when plaque counts were adjusted to a common dilution, the median count for the virucidal glove was on the average reduced >10-fold. In experiments in which the proportion of wells infected with FIV was measured, the ratio of TCID(50) values (control glove to G-VIR) was >15, and probably much higher. For HSV, the amount of virus passing through the virucidal glove was reduced in 81% of comparisons with control gloves; the median of adjusted plaque counts was reduced on the average approximately eightfold or ninefold. In vivo tests with FIV and HSV in cats and mice, respectively, found smaller percentage reductions in infection than the in vitro tests but confirmed the virucidal effect of the gloves.     

Alert surveillance of intensive care unit-acquired Acinetobacter infections in a Sicilian hospital

The epidemiological impact of Acinetobacter baumannii nosocomial infections in a Sicilian intensive care unit (ICU) was investigated to determine the Acinetobacter-specific infection rates, to estimate the preventable proportion of Acinetobacter infections, i.e., those resulting from cross-transmission, and to investigate the molecular epidemiology of antimicrobial resistance in Acinetobacter. The impact of Acinetobacter nosocomial infection in the ICU was determined to be 3.0 new cases per 100 admissions. Site-specific rates confirmed that ICU-acquired pneumonia was the most important infection type. The incidence rate, adjusted by the number of patient-days, was 3.3 infections/1000 patient-days. The estimated preventable proportion of A. baumannii nosocomial infections in the ICU was 66.7%. A class 1 integron, characterised by its gene cassette content, was present in all A. baumannii isolates of four different pulsed-field gel electrophoresis types, and was associated significantly with clones implicated in cross-transmission episodes. Furthermore, the same integron was detected in two genetically distinct isolates responsible for recurrent infection in the same patient, suggesting the occurrence of horizontal gene transfer in vivo. Even in an endemic setting with low infection rates, spread of A. baumannii was caused mainly by infection control shortcomings that require appropriate surveillance and control policies.