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Biomedical subjects

M Landi

Publications and source records attributed to M Landi.

46 records · Page 3Linked to original sources
PubMed1984

Teicoplanin, antibiotics from Actinoplanes teichomyceticus nov. sp. VI. Chemical degradation: physico-chemical and biological properties of acid hydrolysis products.

Teicoplanin is an antibiotic complex consisting of five closely related factors, T-A2-1, 2, 3, 4 and 5 and a more polar factor, T-A3-1. By controlled acid hydrolysis the complex is transformed into pseudoaglycones and finally into a single aglycone with consecutive removal of three sugar units. Quantitative determination of sugars obtained by degradative reactions and NMR/LC-MS studies on suitable derivatives confirmed that all the components carry one N-acyl-D-glucosamine and that at least two of them are characterized by N-decanoyl and N-undecanoyl chains on the D-glucosamine unit. The hydrolysis products still possess in vitro and in vivo activity.

Animals↗
PubMed1983

Relative ability of N-methyl nalorphine and N-methyl levallorphan to prevent antinociception and intestinal transit inhibition in morphine treated rats.

Nalorphine, levallorphan and their quaternary analogs, N-(eq)allyl derivatives of the two diastereoisomers at the nitrogen atom (N-methyl nalorphine and N-methyl levallorphan) were tested for their peripheral selectivity. We compared their relative ability to prevent morphine-induced (5 mg/kg i.v.) antinociception (central antagonism) and constipation (peripheral antagonism) in the same rats. Nalorphine and levallorphan reduced morphine-induced antinociception to half maximal response at doses of 5.1 and 0.89 mg/kg s.c. and restored the intestinal transit to 50% of controls (AD50) respectively at doses of 0.25 and 0.12 mg/kg. N-methyl nalorphine up to 24 and N-methyl levallorphan up to 30 mg/kg given s.c. 10 min before morphine did not antagonize narcotic-induced antinociception, fully preventing constipation (AD50 0.65 and 0.32 mg/kg respectively), but when injected 50 min before morphine they partially lost their antagonist potency (AD50 2.3 and 2.6 mg/kg respectively) and peripheral selectivity. N-methyl nalorphine and N-methyl levallorphan thus seem more peripherally selective than their tertiary analogs and more potent than quaternary narcotic antagonists tested to date.

Analgesia↗
PubMedDate not supplied

Antibody response to Helicobacter pylori CagA and heat-shock proteins in determining the risk of gastric cancer development.

OBJECTIVE: To investigate whether the systemic antibody response to Helicobacter pylori heat shock protein B can be considered, in addition to anti cytotoxin-associated protein [CagA) antibody determination, a further serological marker of increased risk of gastric cancer development. METHODS: A total of 98 Giemsa positive Helicobacter pylori patients (28 with gastric cancer, 30 with duodenal ulcer and 40 with nonulcer dyspepsia) were studied. Serum samples obtained from all patients were tested for IgG antibodies to CagA (116 kDa), VacA [89kDa) and heat skock protein B (54 kDa) antigens of Helicobacter pylori by the Western blot technique. RESULTS: 26/28 patients [(92.9% with gastric carcinoma, 29/30 patients [96.7%) with duodenal ulcer and 30/40 patients (75.0%) with non-ulcer dyspepsia were seropositive for CagA protein. The prevalence of serum IgG antibody to CagA in the cancer patients was not significantly higher than in duodenal ulcer and non-ulcer dyspepsia patients. The prevalence of antibodies to VacA was not significantly different between gastric carcinoma and non-ulcer dyspepsia patients. In contrast the prevalence of systemic antibodies to heat skock protein B was significantly higher in gastric cancer patients (78.6%) than in duodenal ulcer (36.7%, p=0.002) or nonulcer dyspepsia patients (52.5%, p=0.029). CONCLUSIONS: The detection of antibodies to heat shock protein B is proposed as an additional test which, in association with the determination of serum antibodies to CagA, could help in determining the risk of developing severe gastroduodenal disease, and gastric cancer, in particular.

Antibodies, Bacterial↗
PubMedDate not supplied

Positive-outcome bias: comparison of emergency medicine and general medicine literatures.

OBJECTIVE: The existence of positive-outcome bias in the medical literature is well established. Positive-outcome bias in two emergency medicine journals was compared with that found in two general medicine journals. METHODS: Published original contributions from Annals of Emergency Medicine, American Journal of Emergency Medicine, JAMA, and New England Journal of Medicine were reviewed. Articles were categorized as demonstrating a positive or negative outcome or showing no difference using new criteria. Descriptive articles were excluded. RESULTS: Of 700 articles reviewed, 177 emergency medicine and 211 general medicine articles met the study criteria. The emergency medicine journals had 142 articles (80%) with positive outcomes, 27 (15%) with negative outcomes, and 8 (5%) with no difference. The general medicine journals had 169 articles (80%) with positive outcomes, 33 (16%) with negative outcomes, and 9 (4%) with no difference. There was no significant difference between journal groups (chi-square; p = 0.99). The power of the study was 0.80 to detect a difference of 15% between groups with alpha set at 0.05. CONCLUSION: There was no significant difference in the proportions of positive-outcome studies published in this sample of the emergency medicine literature compared with the general medicine literature. The potential impact of positive-outcome bias and methods of dealing with the problem are reviewed.

Emergency Medicine↗
PubMedDate not supplied

Cold-induced rhinitis in skiers--clinical aspects and treatment with ipratropium bromide nasal spray: a randomized controlled trial.

Cold-induced rhinitis (CIR) is common among skiers and is perceived as a troublesome disease. We studied the clinical characteristics of CIR in a population of skiers and we evaluated the effectiveness of ipratropium bromide nasal spray (IBNS) in relieving symptoms in a double-blind placebo-controlled fashion. By means of specific questionnaires, we evaluated 144 subjects (69% men; mean age, 42.2 years). The prevalence of CIR was 48.6% and the distinctive symptom was rhinorrhea (96%), often severe. The prevalence of atopy was higher in the CIR patients (chi2; p = 0.004). Twenty-eight CIR subjects participated in a double-blind placebo-controlled cross-over trial for evaluating the effectiveness of IBNS (80 microg twice per day [b.i.d.]). The severity of symptoms was assessed by a visual analog scale, and the number of cleaning tissues used also was evaluated. The actively treated group showed a significant improvement of rhinorrhea (p = 0.0007) and a reduction in the number of cleaning tissues used (p = 0.0023). Only four mild local side effects were reported. We conclude that IBNS could be regarded as an optimal therapeutic option for treating CIR symptoms in skiers.

Adolescent↗
PubMedDate not supplied

[Case report of Schoenlein-Henoch with neurological complications].

A case of Schönlein-Henoch syndrome with neurological complications in a child is reported. Stress is laid on the fact that these symptoms were predominant throughout the course of the disease. Treatment, primarily based on cortisone, led to complete resolution of the neurological picture.

Child↗