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Biomedical subjects

M Castelli

Publications and source records attributed to M Castelli.

136 records · Page 8Linked to original sources
PubMedDate not supplied

The effects of roxatidine on neuromuscular transmission.

We have investigated the effects of the H2 receptor antagonist roxatidine on the neuromuscular transmission by using the sciatic nerve-gastrocnemius muscle preparation of the rat in vivo. Roxatidine, administered by i.v. injection, potentiates the neuromuscular blockade induced by d-tubocurarine, pancuronium and aminoglycoside antibiotic, kanamycin. Moreover, the drug alone is capable of producing a blockade on the preparation stimulated at high frequency. The neuromuscular blockade induced by roxatidine is partially reversed by 4-aminopyridine but not by dimaprit.

4-Aminopyridine↗
PubMedDate not supplied

Glycyrrhizin and 18 beta-glycyrrhetinic acid: a comparative study of the pharmacological effects induced in the rat after prolonged oral treatment.

Recent clinical and toxicological studies have investigated the mineralcorticoid-like and hypertensive effects of liquorice, and we therefore set out to identify the active component responsible for these effects. We conducted a 30-day comparative analysis of glycyrrhizin and 18 beta-glycyrrhetinic acid and found that the latter causes significant variations both in systolic blood pressure and in the excretion in the urine of Ca++. The effects were fully reversible on suspension of treatment.

Administration, Oral↗
PubMedDate not supplied

Fine needle aspiration biopsy of intraoral and pharyngeal lesions.

Fine needle aspiration biopsy (FNAB) of superficial and deep-seated lesions has been used extensively with high sensitivity and specificity. However, reports of intraoral FNABs are sparse. We present a series of 44 intraoral FNABs performed between September 1988 and January 1992 at Loyola University Medical Center (36 cases) and Hines Veterans Administration Hospital (8 cases). The age of the patients ranged from 29 to 90 years (mean, 61), with 25 males and 19 females. Biopsy sites included buccal mucosal lesions (13 cases), pharynx/nasopharynx (11), tongue (10), tonsils (6), soft palate and epiglottis (2 each). Of the 44 cases, 32 (72.7%) had follow-up surgical biopsy, and 11 (25%) (all with benign diagnosis) were followed clinically. One aspiration was unsatisfactory. Cytologic diagnosis correlated with tissue biopsy in 25 cases (80.6% sensitivity). In six cases the cytologic material did not reveal a neoplasm found in the tissue sections (19.4% false negative). In one case the cytologic diagnosis of malignancy did not correlate with the surgical biopsy (3.1% false positive; specificity, 96.9%). The results of our study suggest that FNAB of intraoral lesions is less sensitive and specific than that of superficial masses. This may be explained by the small size and superficial location of the lesions as well as by the limited space for maneuvering the needle, with difficulty in fixing the lesion for adequate aspiration.

Adult↗
PubMedDate not supplied

Effect of fine needle aspiration biopsy on the histology of thyroid neoplasms.

We evaluated the effect of fine needle aspiration biopsy (FNAB) upon the histology of thyroid adenoma and differentiated thyroid carcinoma. When surgery was performed within three months of FNAB, infarction was found histologically in 8/82 (9.8%) of the tumors. It was extensive in four patients, with one patient having no residual neoplastic cells identifiable within the nodule. No infarction was seen in the histologic specimens from patients with similar pathology whose surgery was performed without prior FNAB. These findings confirm previous reports that infarction may be caused by FNAB and can be so extensive as to interfere with the histologic diagnosis.

Adenocarcinoma↗
PubMedDate not supplied

[Experience with the determination of LDH-X in seminal plasma as diagnostic and prognostic factor in varicocele].

We studied the biochemical and functional properties of semen to evidence markers of diseases concerning fertility. We examined LDH especially isoenzyme LDHx in semen of patients with varicocele, diagnosed by clinical evaluation and doppler velocimetry. The existence of this enzyme is closely associated with active spermatogenesis. In conditions of testicular disease as in varicocele, a major diffusion of LDHx into the seminal plasma may occur as a reaction of the seminiferous epithelium. We evaluated 50 patients (10 normospermic patients, 20 affected by varicocele, 9 azoospermic patients, 11 oligo-astenospermic patients). We observed that the LDHx concentration in seminal plasma is proportional to the severity of the clinical damage. The follow up after spermatic vein ligation of the patients affected by varicocele demonstrated that these patients improved to the normal clinical parameters, associated to a decrease of the concentration of LDHx values.

Adolescent↗
PubMedDate not supplied

Influence of glycyrrhizin on the evolution and respiration of Ehrlich ascites tumour cells.

It has been demonstrated that 18 alpha-glycyrrhetinic acid, 18 beta-glycyrrhetinic acid and glycyrrhizin effectively inhibit the inception and growth of skin tumours. Moreover, glycyrrhizin and its aglycone act on the growth and differentiation of mouse melanoma cells in culture. In this study we investigated the effect of glycyrrhizin, 18 alpha- and 18 beta-glycyrrhetinic acids on the evolution of Ehrlich ascites tumour in mice. A prolonged glycyrrhizin treatment proved to be effective in modifying the animals' survival pattern.

Animals↗
PubMedDate not supplied

Influence of antimalarials chloroquine, quinine, primaquine and mepacrine on the evolution of Ehrlich ascites tumour.

Substances like imidazoles, benzimidazoles and also quinolines, whose chemical structure includes a heterocyclic nitrogen, are known to interfere with the microsomal oxidation and, in some cases, with the metabolism of drugs. Since chloroquine and primaquine exert this effect in vivo and in vitro, we studied the influence of other antimalarials (quinine and mepacrine) in mice with induced Ehrlich ascites tumour (EAT) to find out whether variations in oxygen consumption affected the course of the disease. In vitro data, obtained by a polarographic technique, indicate that primaquine and, in particular, mepacrine increase EAT-cell oxygen consumption, while in vivo data, obtained in mice injected with an inoculum of about 1 x 10(6) tumour cells per mouse, show that both drugs, but notably mepacrine, accelerate tumour growth, as monitored by Cox's statistical method for body weight, and lead to earlier death. In cases of existing neoplasia, therefore, the potentially toxic effects of certain antimalarials must be borne in mind.

Animals↗
PubMedDate not supplied

Role of chemotherapeutic antagonism in opportunistic infections.

The most widely-known anti-tumor drugs often induce marked immunosuppression which can give rise to one or more sepses. Anti-infection measures immediately applied can sometimes prove largely ineffective or even useless, the patient dying not as a result of the spread of the tumour but as a direct consequence of opportunistic infection. We postulate that antagonism between anti-tumour and antimicrobial drugs may also play an important part in this. By way of illustration of this hypothesis, we have studied the action of a number of known inhibitors of peptidoglycan synthesis and of DNA-gyrases on certain strains of Gram-positive and Gram-negative microorganisms cultured in medium containing various concentrations of some of the best-known anti-tumour antimetabolites. The experimental data show that antimicrobial and anti-tumour drugs can sometimes induce synergic or indifferent chemotherapeutic interactions with many bacteria, while in others the effect is antagonistic. In practice, the action of the drugs could lead to bacterial selectivity, which, in conjunction with immunosuppression and the presence of resistant strains, could favour the evolution of opportunistic infection.

Anti-Bacterial Agents↗