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Biomedical subjects

M Goldberg

Publications and source records attributed to M Goldberg.

At least 451 records · Page 25Linked to original sources
PubMed1987

FMRF-amide-like immunoreactive efferent fibers and FMRF-amide suppression of pacemaker neurons in eyes of Bulla.

The eyes of certain marine gastropods including Aplysia and Bulla, contain circadian pacemakers, which produce a circadian rhythm of autogenous compound action potential (CAP) activity. The CAPs are generated by the synchronous spike discharge of a distinctive population of retinal pacemaker neurons whose axons convey the CAP activity to the CNS. When CAP activity is recorded from a preparation with eyes attached to the CNS, the CAP activity is modulated by efferent activity. In this study we have identified FMRF-amide-like immunoreactive efferent axons in the optic nerves of Bulla. These axons arborize in the basal retinal neuropil adjacent to the pacemaker neurons and are in a position to make synaptic contacts with their dendrites. Similar immunoreactive fibers are not observed in Aplysia eyes. Exogenous FMRF-amide at micromolar concentrations suppresses ongoing CAP activity in isolated eyes but does not suppress the ERG or phase shift the circadian rhythm of CAP activity. Intracellular recordings from the retinal pacemaker neurons reveal that FMRF-amide hyperpolarizes the membrane potential, suppresses spike discharge, and decreases the input resistance, suggesting that a K conductance is increased. Electrical stimulation of the region of the cerebral ganglion that contains FMRF-amide immunoreactive neurons suppresses ongoing CAP activity. All these results are consistent with the idea that the FMRF-amide immunoreactive central neurons and their axons provide a pathway for efferent modulation of the CAP rhythm generated by the retinal pacemaker neurons.

Animals↗
PubMed1987

4-Aminosalicylic acid retention enemas in treatment of distal colitis.

Forty-five of 47 patients with distal ulcerative colitis completed a two-week double-blind, randomized, controlled trial to determine if 4-aminosalicylic acid (4-ASA) enemas, 1 g bid or 2 g bid, were therapeutically effective compared to placebo. Forty-one patients enrolled because they were refractory to or had side effects during conventional therapy with sulfasalazine or corticosteroids. Proctoscopic examination was done before and after two weeks of treatment. Patients kept daily diaries assessing: blood in stools, mucus in stools, tenesmus, abdominal pain, loss of appetite, fatigue, weight loss, and malaise. Severity of each symptom ranged from 0 (absent) to 3 (severe). A total severity score was calculated from the above for each patient. At the end of the two-week study, 35 patients elected to take 4-ASA in an open-label trial for one year. 4-ASA enemas in the 1-g bid but not the 2-g bid dosage were significantly more effective in improving symptoms than placebo: P less than or equal to 0.05. Neither dose of 4-ASA enema was better than placebo in improving the sigmoidoscopic appearance at the end of two-weeks. Forty-six percent of patients had complete resolution of all signs and symptoms in the open-label trial and 31% were better but still had sigmoidoscopic evidence of disease, a total response rate of 77%. Side effects were similar in the placebo and 4-ASA groups. We conclude that 4-ASA enemas in a dose of 1 g bid are safe and effective in the treatment of distal ulcerative colitis.

Adult↗
PubMed1987

Biochemical and scanning electron microscope study of lipids chloroform-methanol extracted from unerupted and erupted human tooth enamel.

Almost twice as much fatty acid was extracted without demineralization from the mature enamel of erupted teeth treated with 2:1 chloroform-methanol as from the enamel of unerupted teeth (32.64 micrograms/g versus 15.60 micrograms/g). Palmitic C16:0, stearic C18:0, oleic C18:1 omega 9 and linoleic acids C18:2 omega 6 were the chief fatty acids detected by gas-liquid chromatography. The percentage of free fatty acids and diglycerides was larger in unerupted than erupted teeth, whereas that of triglycerides, phosphatidylethanolamine and phosphatidylcholine was larger in erupted teeth. These changes may be due to bacteria and other contaminants (saliva and pellicle). The large amounts of free fatty acids, diglycerides, cholesterol and phospholipids as intrinsic components were probably due to the persistence of membrane remnants entombed during enamel formation, as indicated by the visualization of holes and by the increase in the size and number of focal holes after lipid-solvent interaction with the enamel surface. These defects always occurred in rods and never in inter-rod material. Other minute defects, including empty-widened intercrystal spaces, were also observed inside some rods.

Adolescent↗
PubMed1987

Inhibition by the mushroom toxins alpha-amanitin and phalloidin of hepatopoietin-induced 3H-thymidine incorporation into rat liver DNA and of plasma protein production in hepatocyte cultures.

In primary cultures of rat hepatocytes the induction of 3H-thymidine uptake into DNA of liver cells by the liver cell proliferation factor hepatopoietin demonstrates that this factor is active not only in vivo but also in vitro. Addition of the mushroom toxins alpha-amanitin or phalloidin to liver cell culture decreased the uptake of 3H-thymidine into hepatocytes (in the absence or presence of hepatopoietin) as well as the attachment of the hepatocyte cultures. Mushroom toxins also inhibited the production of plasma proteins in hepatocyte cultures. The inhibition, observed at toxin concentrations from 10(-5) to 10(-7) M, was dose-dependent. At low concentrations of phalloidin the inhibition appears to be selective for certain proteins.

Amanitins↗
PubMed1987

Significance of metastatic disease in subaortic lymph nodes.

Thirty-five patients underwent resection of primary bronchogenic carcinoma of the left upper lobe or left main bronchus in the presence of metastatic disease in subaortic lymph nodes. No patient had metastatic disease in other mediastinal node stations. There was 1 postoperative death. Complete follow-up is available on 34 patients. Three-year and five-year actuarial survival for the entire group is 44% and 28%, respectively. For 23 patients undergoing complete resection, five-year actuarial survival is 42%. Resection of primary bronchogenic carcinoma in the presence of subaortic nodal metastases is associated with improved survival relative to reports of survival following resection of metastatic disease in other mediastinal node stations. Resection should be undertaken in these patients especially when it is judged that the resection is likely to be complete.

Adult↗
PubMed1987

Biological efficacy of partial hepatectomy and hepatopoietin in long-term selenium-deficient mice.

After partial hepatectomy the normal low proliferation rate of hepatocytes increases dramatically. This is based on a feed-back system whose central link is a liver cell proliferation hormone, the so-called hepatopoietin. This glycoprotein is organ-specific but not species-specific, i.e. an extract from rats is also active in mice. In order to examine the influence of selenium on liver cell proliferation, male albino NMRI mice were fed a selenium-deficient diet containing less than 10 ppb Se for at least 2 months (Se-). In the plasma protein profile and in the basic DNA synthesis rate of Se(-)-animals, no significant changes were observed compared to controls. However, liver cell proliferation induced by hepatopoietin or by partial hepatectomy was increased about 3-fold in Se-deficient mice. We assume a compensated metabolic Se-deficiency state in mice under these nutritional conditions, which leads to expression of enhanced metabolic capacity when induced by stress.

Animals↗
PubMed1987

Spontaneous perforation of the stomach in the neonate.

Three full-term female neonates developed gastric perforation during their first week of life. All three experienced severe postnatal asphyxia and improved following resuscitation. A linear perforation located in the prepyloric area was found in these patients. Direct closure was successfully performed in all three neonates. Asphyxia seems to be a major predisposing factor in neonatal gastric perforations. Focal gastric ischaemia and acid peptic activity may play part in the pathogenesis in these cases.

Female↗
PubMed1987

Partly native epitopes are already present on early intermediates in the folding of tryptophan synthase.

Two monoclonal antibodies directed against the native beta 2 subunit of Escherichia coli tryptophan synthase [L-serine hydro-lyase (adding indoleglycerol-phosphate), EC 4.2.1.20], one recognizing the C-terminal F1 domain and the other the N-terminal F2 domain, were used to detect immunoreactive intermediates in the folding of the protein. For that purpose, the association of the monoclonal antibodies with either the beta 2 subunit or its isolated domains was studied by using fluorescence energy transfer between tryptophan residues of the antibodies and a dansyl group covalently linked to the antigen. It is shown that the association of both monoclonal antibodies with the antigen occurs within a few seconds after initiation of the renaturation, whereas complete refolding of the beta 2 subunit requires several minutes under the same experimental conditions. Thus, immunoreactive intermediates appear to be formed at an early stage of the folding process. While the isolated F1 domain alone is able to rapidly refold into a conformational intermediate already well recognized by the anti-native-beta 2 antibody, it cannot, in the absence of the F2 domain, reach its native conformation. However, its association with the anti-native-beta 2 antibody induces a structural change of F1 that brings it closer to the conformation it normally adopts when interacting with F2 inside the native beta 2 subunit.

Antibodies, Monoclonal↗
PubMed1987

Sickness absence at the French National Electric and Gas Company.

The certified sickness absence of workers in the French National Electric and Gas Company was studied for 12 months and has been described according to the demographic and occupational characteristics of the employees. The results showed that the principal factors affecting absence are sex, job, and salary. The high percentage of absent women was explained by neither the type of occupation nor family status. Respiratory diseases, accidents, and musculoskeletal and psychiatric disorders were the leading diagnostic categories. Indices of severity, duration, and frequency were calculated and compared between groups. The duration of absence increased with the severity of the medical cause of absence and with the patient's age.

Absenteeism↗
PubMed1987

Comparative in vitro activity of carumonam (Ro 17-2301/AMA-1080), a new monobactam, and ceftriaxone against aerobic or facultative gram-negative isolates.

Carumonam (Ro 17-2301/AMA-1080) is a new monobactam antibiotic. A comparative in vitro evaluation with ceftriaxone was undertaken against 153 gram-negative clinical aerobic or facultative bacteria, both producers and nonproducers of beta-lactamase. Results indicated that carumonam had an enhancement of activity for Pseudomonas aeruginosa, Klebsiella oxytoca, Citrobacter freundii and Enterobacter cloacae and parallelled that of ceftriaxone against Escherichia coli, Klebsiella pneumoniae, Proteus spp. and Serratia marcescens. It can be concluded that carumonam could be an alternative of interest for the treatment of patients with infections due to gram-negative strains presumably or proven to be multiresistant.

Anti-Bacterial Agents↗