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Biomedical subjects

M Lanza

Publications and source records attributed to M Lanza.

At least 37 records · Page 2Linked to original sources
PubMed1993

CGP 52432: a novel potent and selective GABAB autoreceptor antagonist in rat cerebral cortex.

As previously reported GABAB receptors are heterogeneous. Three pharmacologically distinct receptor subtypes mediating inhibition of gamma-aminobutyric acid (GABA), glutamate or somatostatin release, respectively, exist on axon terminals of rat cerebral cortex. We investigated the novel GABAB receptor antagonist, [3-[[(3,4-dichlorophenyl)methyl]amino]propyl](diethoxy-methyl) phosphinic acid (CGP 52432), on the above receptor subtypes. The effects of (-)-baclofen on the K(+)-evoked release of GABA, glutamate or somatostatin from rat cortical synaptosomes were antagonized by CGP 52432. The IC50 of the drug at GABA autoreceptors (0.085 microM) was 35- and 100-fold lower than at the receptors regulating somatostatin and glutamate overflow, respectively. At the autoreceptor the calculated pA2 for CGP 52432 amounted to 7.70, which makes the drug about 1000-fold more potent than phaclofen at this receptor. The potency and selectivity characteristics of CGP 52432 indicate that the drug is by far the most appropriate tool to investigate the terminal GABAB autoreceptors of the rat cerebral cortex.

Animals↗
PubMed1993

Release of endogenous glutamic and aspartic acids from cerebrocortex synaptosomes and its modulation through activation of a gamma-aminobutyric acidB (GABAB) receptor subtype.

The depolarization-evoked release of endogenous glutamate (GLU) and -aspartate (ASP) and its modulation mediated by gamma-aminobutyric acid (GABA) heteroreceptors was investigated in superfused rat cerebrocortical synaptosomes. Exposure to 12 mM K+ enhanced the release of GLU and ASP. The K(+)-evoked overflow of both amino acids was largely Ca(2+)-dependent. Exogenous GABA inhibited the K(+)-evoked overflow of GLU (EC50 2.8 microM) and ASP (EC50 2.7 microM). The effect of GABA was mimicked by the GABAB receptor agonist (-)-baclofen (EC50 2.0 microM for GLU and 1.3 microM for ASP release) but not by the GABAA receptor agonist muscimol, up to 100 microM. Accordingly, the GABA-induced inhibition of GLU and ASP release was not affected by the GABAA receptor antagonists, bicuculline or picrotoxin, but was antagonized by the GABAB receptor antagonist, 3-amino-propyl(diethoxymethyl)phosphinic acid (CGP 35348). The GABA effect was, however, insensitive to another GABAB receptor antagonist, phaclofen, up to 1,000 microM. It can be concluded that GABA heteroreceptors of the GABAB type regulating the depolarization-evoked release of GLU and ASP are present on cortical GLU/ASP-releasing nerve terminals. These receptors may be classified as a phaclofen-insensitive GABAB receptor subtype.

Animals↗
PubMed1993

[A rare cause of hypercalcemia: familial hypocalciuric hypercalcemia].

BACKGROUND: Familial hypocalciuric hypercalcemia is a rare disease with autosomal dominant transmission. Its basic defect is unknown and it requires no treatment. CASE REPORT: A 4 month-old girl was admitted for unexplained crying. She was found to have hypercalcemia (2.8 mmol/l) and later values of blood calcium were 3, 3.1 and 3 mmol/l. The serum free ionic calcium level was also elevated. The serum concentrations of protein, phosphorus, magnesium and the alkaline phosphatase activity were all normal. Serum concentrations of 25-(OH)-D3, 1.25-(OH)-2-D3 and PTH were also normal. The urinary calcium/creatinine ratio was normal and the urinary calcium excretion was 1.08 mg/kg/d. Screening of family members showed hypercalcemia in the father (2.8 mmol/l) and a brother aged 7 years (2.9 mmol/l). Short-term treatment with disodium etidronate lowered the serum calcium level to normal, but hypercalcemia reappeared once the treatment was discontinued. CONCLUSIONS: This asymptomatic familial hypercalcemia has the characteristics of familial hypocalciuric hypercalcemia. There was no associated endocrine disorder. Screening of family members is worthwhile.

Calcium↗
PubMed1990

[Research on Kathon CG in cosmetic and personal hygiene products].

Kathon is an anti-microbial agent that is used as a preservative in cosmetics and bodily hygiene products. At the recommended levels of usage Kathon is innocuous and has a recognised efficacy. Nevertheless, following reappearance of contact allergic eczemas due to cosmetics and bodily hygiene products different authors have reported increase in sensitisation to it. We have met the same problems in the Service de Dermatology++ of the Hospital Sainte Marguerite at Marseille and we wished to make a deeper examination of the question and to ascertain whether the current cosmetics contained Kathon CG. For this we have developed a technique of liquid chromatography and tested 44 creams. Eight contained Kathon CG, of which 2 were responsible for contact eczema in patients.

Chromatography, High Pressure Liquid↗
PubMed1985

[Non-secretory plasmacytoma. Bibliographic review and immunohistochemical study of a case].

After a brief examination of the recent literature on non-secretory multiple myeloma, the Authors describe the immunohistologic study (peroxidase-antiperoxidase method) of a case of truly non producing plasmacytoma, interesting because of the presence of a small polyclonal plasma cell population within the neoplastic clone. Several possible explanations are considered.

Aged↗
PubMed1985

[Plasma cell leukemia. Bibliographic review and ultrastructural study (by transmission and scanning electron microscopy) in 2 cases].

After a brief examination of the recent literature on plasma cell leukemia, the Authors describe the clinical features and the ultrastructural findings of the peripheral blood plasma cells, examined with transmission (T.E.M.) and scanning (S.E.M.) electron microscopes, of two patients with acute plasma cell leukemia. Both of them had a previous history of myeloma. T.E.M. confirmed the diagnostic value of the asynchronous plasma cells, and S.E.M. showed the characteristic microvilli and blebs, previously observed.

Aged↗
PubMed1984

[Autoantibodies and respiratory allergy: immunologic case study].

Sera obtained from 212 patients with rhinopathy and/or asthma of allergic origin (pollens and/or mites) and from 87 apparently healthy controls were studied for the presence of organ and non organ specific autoantibodies. These were determined by indirect immunofluorescence techniques (5) using test tissue from monkeys (thyroid) and rats (stomach, liver and kidney). Two groups were matched for age and sex and the tests were performed using the double-blind method. The incidence observed was not dissimilar to that detected in healthy subjects, with the exclusion of smooth-muscle antibodies. These were present to a lesser extent in patients with respiratory allergies (0.94%) in contrast with the incidence of 5.73% in normal subjects (P less than 0.01). On the basis of our findings, it seems possible to hypothesize that allergic patients have a lesser tendency to autoimmune diseases because the immune system is committed to the IgE-mediated immunoreactions. In conclusion, autoantibodies do not seem to play a role in the pathogenesis of respiratory allergies to inhaled allergens.

Adult↗
PubMed1983

[1-year monitoring of the course of chronic renal insufficiency induced by subtotal nephrectomy in rats. Pharmacokinetic value].

A subtotal nephrectomy is realized on 200 rats Wistar IOPS, producing a chronical renal failure (CRF). Evolution is studied during 12 months and compared to 100 normal rats of the same age. Biochemical criteria show an increased blood urea and creatinemia with a diminution of creatinin clearance and an appearance of important proteinuria. Morphological results show as soon as the third month, irreversible tubulo-interstitial lesions; afterwards glomerular lesions appear and become more and more visible and are accompagnied by membranous depots; then, a pan-nephritis is noted at the 10th month. These observations allow to class animals into three groups according to the CRF degree: low, medium or severe. As soon as the fifth month, all surviving animals present a medium CRF generally, or a severe CRF. Our work allows to create homogeneous lots used in pharmacokinetic applications.

Animals↗
PubMed1979

[Effect of a single dose of some long-acting neuroleptics on the estrus cycle and the mammary gland of the rat].

The effects of two neuroleptics (pipotiazine and fluphenazine) and five long-acting neuroleptics (pipotiazine undecylenate and palmitate, fluphenazine enanthate and decanoate, fluopentixol decanoate) are tested in the rat, during an observation period of 20 to 40 days following only one injection of compound. The compounds administered at three different and non toxic doses, are showing effects, the intensity and duration of which are different according to the dose and the compound: diestrus of pseudo-gestation or more than 15 days, hypertrophy of mammary gland, decreasing of the uterine weight. Some long-acting neuroleptics are active during more than forty days.

Animals↗
PubMed1978

[Diabetes insipidus and exogenous antidiuretic hormone activity modifications by lithium in the rat].

The authors made conspicuous in the rat the appearance of "diabetes insipidus" induced by two lithium salts: chloride and carbonate administered orally, with increasing doses in food. The polyuria, polydipsia and urinary hypotony are reversible and disappeared with stopping the treatment. The animals became insensible to the exogenous antidiuretic hormon during the treatment and progressively became sensible again during the following twenty days so suggesting a nephrogenic mechanism by lithium: either a loss of ADH activity, either the abolition of intrarenal osmotic pressure gradient.

Animals↗