The control of chloride conductance in rat parotid isolated acinar cells investigated by photorelease of caged compounds

The control of Cl^– conductance in rat parotid isolated acinar cells was studied by combined use of whole-cell recording and flash photolysis techniques. Cells were voltage-clamped either at a membrane potential of –40 mV or stepped between –85 mV and 0 mV. Bath-applied carbachol and noradrenaline evoked Cl^– current at –85 mV and K⁺ current at 0 mV. Similar current activations resulted from the photolytic release of either inositol trisphosphate (InsP ₃) or Ca²⁺ by a brief near-UV flash. The peak amplitudes of the Cl^– conductance (at –85 mV), measured relative to the K⁺ conductance (at 0 mV), evoked by application of carbachol, noradrenaline or direct manipulation of cytosolic free calcium ([Ca²⁺]_i), were very similar, being 0.56±0.09 (mean±SEM,n=9), 0.52 ± 0.01 (n=7) and 0.46±0.06 (n=7). In contrast, the relative amplitude of the Cl^– conductance evoked by InsP₃ was much larger: 1.49±0.24 (n=9). Neither bath application of isoprenaline nor photolysis of caged cAMP induced any detectable membrane current. The most probable interpretation of these results is that the observed activation of Cl^– conductance by agonists can be explained by the elevation of [Ca²⁺]_i alone. In addition, the present results provide further support for the previously reported suggestion that the Cl^– channels and the Ca²⁺-release sites are co-localised [10].     

Serum alpha 2-macroglobulin levels in diabetes.

Serum alpha 2-macroglobulin levels have been determined in diabetic patients by quantitative radial immunodiffusion and compared with those observed in age- and sex-matched controls. In addition, the results in diabetics have been analysed with respect to such variables as the age and sex of the patient, the duration of disease, treatment, control, and the occurrence of retinopathy or nephropathy. The alpha 2-macroglobulin levels in diabetic patients were found to be significantly higher than in age- and sex-matched controls, thus confirming previous observations. However, these differences were most apparent in the more extreme age groups. Multiple regression analysis also revealed that the only variables contributing significantly to the regression apart from age and sex were control and retinopathy.     

Diversity of enteric viruses detected in patients with gastroenteritis in a tertiary referral paediatric hospital

The genetic diversity of enteric viruses co-circulating in a cohort of patients with viral gastroenteritis in a large tertiary paediatric hospital in London, UK, was determined. Multiple strains of noroviruses (NV), sapoviruses (SV) and astroviruses (HAsV) were detected in these patients, indicating the likelihood of multiple introductions from different sources, possible sub-clinical infections and simultaneous infection with different viruses in immunocompromised and other patients. Routine screening of immunocompromised patients and infection control procedures are important to prevent nosocomial infection.     

Polymorphisms in the MAOA, MAOB, and COMT genes and aggressive behavior in schizophrenia.

Some studies have reported associations between COMT and MAO genotypes and aggression, though results have been inconsistent. We examined the relationship between Overt aggression scale (OAS) scores, and both MAOA and MAOB polymorphisms in a well-powered sample of 346 subjects with schizophrenia. We also examined COMT in a Stage II replication sample of 150 individuals, and combined these results with our previously reported (Stage I) findings for COMT. We found no evidence of any associations between OAS ratings and any of the polymorphisms investigated under different genetic models. There was no evidence of epistatic interaction between MAOA and COMT on OAS scores. These results fail to support the theory that functional polymorphisms within the MAOA, MAOB, or COMT genes, as determinants of catecholamine enzymatic activity, are risk factors for aggressive behavior.     

A European multicenter study of immunoblotting in serodiagnosis of lyme borreliosis

A European multicenter study of immunoblotting for the serodiagnosis of Lyme borreliosis showed considerable variation in results obtained from tests with a panel of 227 serum samples. Six laboratories used different immunoblot methods, and a wide range of bands was detected in all the assays. Multivariable logistic regression analysis of data from individual laboratories was used to determine the most discriminatory bands for reliable detection of antibodies to Borrelia burgdorferi sensu lato. These bands were used to construct individual interpretation rules for the immunoblots used in the six laboratories. Further analysis identified a subset of eight bands, which were important in all the laboratories, although with variations in significance. Possible European rules, all closely related, were formulated from these bands, although there was no single rule that gave high levels of sensitivity and specificity for all the laboratories. This is a reflection of the wide range of methodologies used, especially the use of different species and strains of B. burgdorferi sensu lato. The panel of European rules provides a framework for immunoblot interpretation which may be adapted in relation to the characteristics of Lyme borreliosis in local areas.     

Affective modulation of the startle response in depression: influence of the severity of depression, anhedonia, and anxiety

BACKGROUND: The amplitude of the startle reflex response is known to be influenced by the concomitant presentation of affect-toned material--if it is positive affect-toned, the reflex is inhibited, and if it is negative affect-toned, the reflex is augmented. Abundant evidence demonstrates the utility of the affect-startle paradigm as a significant tool for measuring both positive and negative emotions. We applied this paradigm to study emotional reactivity in depression, particularly in relation to symptoms of depression, anhedonia, and anxiety. METHODS: Depressed patients (22) and controls (22) were shown a series of film clips, consisting of two clips with positive valence, two with negative valence, and two with relatively neutral valence. The startle response was measured in reaction to the acoustic startle-eliciting stimuli presented three times binaurally during each clip. RESULTS: Highly depressed and anhedonic patients, relative to controls, showed a reduced mood (self-ratings) and a lack of startle modulation in response to affective film clips whereas patients relatively low on depression/anhedonia displayed a reduced mood only with pleasant clips and a normal pattern of affective startle modulation. Anhedonia and depression were highly positively correlated but neither correlated with anxiety. Anxious patients displayed larger reflexes across all clips and showed a reduced mood modulation with pleasant, but not unpleasant, clips. LIMITATIONS: The large majority of patients was medicated with antidepressants which may have influenced the results. CONCLUSIONS. Reactivity to pleasant stimuli is diminished in patients suffering from low levels of depression and/or anhedonia, but reactivity even to unpleasant stimuli seems compromised at high levels of depression and/or anhedonia. Anxiety is associated with hyperstartle responding.     

Rotavirus gastroenteritis and central nervous system (CNS) infection: characterization of the VP7 and VP4 genes of rotavirus strains isolated from paired fecal and cerebrospinal fluid samples from a child with CNS disease

Rotavirus RNA was detected in the cerebrospinal fluid (CSF) of a child with central nervous system disease symptoms associated with rotavirus gastroenteritis. The rotavirus isolates from the fecal and CSF samples were genotyped as G1P[8]. Sequence analysis of the VP7 and VP4 proteins derived from the fecal and CSF samples were remarkably similar to each other and to G1P[8] rotavirus strains commonly circulating in the community and associated with gastroenteritis.     

Demonstration of carcinoembryonic antigen in bone marrow from patients with carcinoma.

Primary and secondary tumour and bone marrow trephine biopsies from 20 patients with carcinomas were stained for carcinoembryonic antigen by the three stage immunoperoxidase method. Six marrow biopsies contained tumour deposits, five of which were positive for carcinoembryonic antigen. A further five marrow biopsies contained single carcinoembryonic antigen positive cells of uncertain origin. Carcinoembryonic antigen staining may be a useful adjunct to conventional histology in the diagnosis of marrow metastases.     

Expression of the 17-1A antigen in gastric and gastro-oesophageal junction adenocarcinomas: a potential immunotherapeutic target?

BACKGROUND: A murine monoclonal antibody against the 17-1A epithelial antigen has been shown to be a useful adjuvant therapy in colorectal cancer. Its clinical use could be extended to patients with upper gastrointestinal adenocarcinoma. AIM: To determine the distribution of the antigen in gastric and oesophageal adenocarcinoma. METHODS: The activity of two monoclonal antibodies active against 17-1A epithelial antigen was studied in gastric and gastro-oesophageal junction adenocarcinomas: fresh frozen tissue from both the carcinoma and adjacent mucosa was stained using immunocytochemistry with a murine monoclonal antibody (17-1A edrecolomab, Glaxo Wellcome); paraffin embedded tissue was stained using the humanised monoclonal antibody 3622W94 (Glaxo Wellcome). RESULTS: 29 of 33 cancers (88%) stained with the murine antibody and 39 of 40 (98%) with the humanised antibody. The degree of staining was greater in well differentiated and moderately differentiated tumours. There was no staining of the normal background gastric or oesophageal mucosa, but areas of intestinal metaplasia stained intensely. The humanised monoclonal 3622W94 antibody produced more intense staining than the murine antibody. CONCLUSIONS: The high incidence of expression of the 17-1A antigen in patients with gastric and gastro-oesophageal junction adenocarcinomas suggests a potential role for these antibodies as an adjuvant treatment for these common cancers.     

The role of calcium in parotid amylase secretion evoked by excitation of cholinergic, α- andβ-adrenergic receptors

Pflügers Archiv - European Journal of Physiology -