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Biomedical subjects

F Villa

Publications and source records attributed to F Villa.

At least 19 recordsLinked to original sources
PubMed1991

Evaluation of DNA damage induced by norfloxacin in liver and kidney of adult rats and in fetal tissues after transplacental exposure.

Norfloxacin, a recently developed antimicrobial fluoroquinolone, was investigated for DNA-damaging activity in rat liver and kidney. After oral administration of single doses ranging from 1 to 8 mmole/kg, DNA fragmentation was absent in liver and kidney both 2 and 6 h after treatment. However, when administered to pregnant rats, the highest doses produced a detectable amount of DNA damage in fetal tissues. This damage appears to be an aspecific consequence of maternal and fetal toxicity rather than a specific genotoxic effect.

Animals↗
PubMed1989

[Fibrous dysplasia of the jaws. The literature and a presentation of 2 cases].

After an analysis of the literature, the clinical, roentgenographic, anatomopathologic and therapeutic features of fibrous dysplasia of the jaws have been described. Two cases have been presented: a fifteen-year-old boy affected by a monostotic form of the right maxilla and a nineteen-year-old girl affected by a craniofacial variety, restricted to the right zygomatic and maxilla bones.

Adolescent↗
PubMed1988

Measurement of glomerular filtration rate by impulse synthesis: clinical validation and optimization.

Impulse synthesis is a technique which relies upon the logic of continuous infusion but extracts the clearance value from single-injection data by shifting and adding them until an asymptotic value is attained. This study has been aimed at validating and optimizing clinically the measurement of glomerular filtration rate by impulse synthesis. A single intravenous injection of 51Cr-EDTA has been made in 32 patients and plasma activity monitored over the next 6 h. Glomerular filtration rate computed by a single-exponential fit method (GFR-SEF) has been shown to be significantly (p less than 0.001) overestimated when compared with the glomerular filtration rate obtained by the impulse synthesis technique (GFR-IS) in spite of an excellent (r = 0.989) linear correlation between the two sets of data. On the other hand, the comparison between GFR-IS and 24-h creatinine clearance has not shown any significant difference. Moreover, we have found that in patients with severe renal failure GFR-IS is overestimated when the sampling time span is shortened to 3 h. On the other hand, GFR-IS is slightly underestimated in patients with severe renal failure when the convolution time interval is increased over a few minutes.

Adult↗
PubMed1986

Growth hormone response to hpGRF-40 in different forms of growth retardation and endocrine-metabolic diseases.

The effect of one of the new human pancreatic growth hormone releasing factors (hpGRFs) was assessed in children or young adults with different forms of growth retardation or endocrine-metabolic diseases. Intravenously administered synthetic hpGRF-40 (1 microgram/kg) induced a clear-cut and prompt rise in plasma growth hormone (GH) levels in 8 normal prepubertal children and a definite GH rise in 11 out of 14 children with isolated GH deficiency (IGHD) and one child with the Silver-Russel syndrome. In two out of three subjects with craniopharyngioma hpGRF-40 did not induce any plasma GH increase. In seven out of ten children with constitutional growth delay (CGD), hpGRF-40 induced a biphasic GH response, with a prompt small GH increment followed by a second, more consistent rise. Both in children with IGHD and with CGD the rise in plasma GH following hpGRF-40 was markedly lower than in controls. In children with CGD the GH response to hpGRF-40 was defective, despite the fact that in most of them the GH response to standard pharmacological stimuli was normal according to generally accepted criteria. hpGRF induced a small but sustained plasma GH rise in four hypothyroid subjects, while in three out of four children with idiopathic obesity the GH response to hpGRF was strikingly reduced. These data demonstrate that hpGRF is a potent stimulus of GH release in normal prepubertal children and a physiological means of investigating GH function in diseases associated with growth impairment.

Adolescent↗
PubMed1982

Natural cytotoxic activity in human lungs.

Disease-free surgical lung specimens from 13 patients with neoplastic or infectious diseases and from three subjects with non-neoplastic, non-infectious pathology were mechanically disaggregated. Natural cytotoxicity was tested against 51Cr-labelled K562 target cells. Unseparated lung cells had little cytotoxicity against K562 cells. Removal of plastic and nylon-wool-adherent cells resulted in cell preparations (morphologically 80% lymphoid) with increased cytolytic activity against K562 but cytotoxicity levels were considerably lower than those of blood lymphocytes tested in parallel. Similar results were obtained when phagocytic adherent cells were removed with carbonyl iron. The NK-resistant murine TU5 and human Raji lines were not affected by lung effector cells. In vitro exposure to partially purified fibroblast interferon enhanced the cytotoxicity of unseparated or non-adherent lung cells. Thus, unlike in mouse pulmonary tissue, low levels of natural cytotoxic activity are associated with the humans lung.

Cell Survival↗
PubMed1982

Inhibition of natural killer activity by human bronchoalveolar macrophages.

Mononuclear phagocytes were isolated by adherence from peripheral blood, peritoneal exudates, early lactation milk, ovarian carcinomatous ascites and bronchoalveolar lavages. Their capacity to modulate natural killer (NK) activity was assessed by mixing them with blood lymphocytes and by measuring lysis of 51Cr-labeled K562 cells. Unlike other mononuclear phagocyte populations, alveolar macrophages caused a marked dose-dependent inhibition of NK activity. Significant inhibition (40%) of the expression of cytotoxicity was evident at a ratio of alveolar macrophages to lymphoid cells of 0.12:1, and more than 80% suppression was usually observed at a ratio of 0.5:1. Blood monocytes, peritoneal and milk macrophages were consistently inactive up to the highest ratio tested, 2:1. Inhibition of the expression of NK activity by alveolar macrophages was observed at lymphocyte to K562 ratios ranging from 6:1 to 100:1 and over a 4 h or 20 h 51Cr release assay. Alveolar macrophages also inhibited interferon-stimulated cytotoxicity. Alveolar macrophages are unique among the mononuclear phagocyte populations studied in their capacity to inhibit the expression of NK activity effectively, and they could play a role in determining the low levels of NK activity associated with human pulmonary tissue.

Ascitic Fluid↗
PubMed1979

Prompt endoscopic diagnosis of upper gastrointestinal hemorrhage: its value for specific diagnosis and management.

From July 1, 1973 to June 30, 1976 789 patients admitted as upper gastrointestinal bleeders had endoscopies performed within 24 hours after preliminary resuscitation and preparation. More than one lesion was found in approximately 45% of the patients. Erosive hemorrhagic gastritis was the most common lesion, being present in 27.3--48.2% of the subjects (the latter precentage was found in those with a history of intake of both alcohol and ulcerogenic drugs). Gastric ulcer was the next most common lesion, present in 16.3--18.42%; the higher percentage represents the patients who were taking ulcerogenic drugs. The highest incidence of gastric ulcer (19.59%) or duodenal ulcer (10.5%) was among the patients in a group who had no apparent definite cause for the bleeding. A small number of patients had rare causes for the bleeding and in only a small percentage of the patients was the cause not diagnosed. These data suggest that early endoscopy is of diagnostic value in upper G.I. bleeders leading to prompt, lifesaving management and prevention of prolonged morbidity.

Adolescent↗
PubMed1976

[Spectroscopic study of the structural changes of scorpion hemocyanin, induced by pH variations and addition of various salts].

Structural modifications of the scorpion haemocyanin induced by pH variations and salt addition are studied by U.V. absorption, fluorescence, circular dichroism and light scattering. Haemocyanin fluorescence is due to both aromatic amino-acids tyrosine and tryptophan. Deoxygenation or denaturation lead to a fourfold enhancement of its intensity. At acidic pH the active site is modified and the protein is dissociated, but at alkaline pH the haemocyanin aggregates. The addition of different salts (sodium citrate, potassium bromide and iodide...) involves protein dissociation, the amplitude of which depends on the anion. But pH variations and salt addition don't change the haemocyanin secondary structure as shown by circular dichroism. The C.D. spectrum of scorpion haemocyanin exhibits the characteristic bands of Arthropod haemocyanine.

Animals↗
PubMed1975

Hepatocellular carcinoma: relation to alcohol, HB-antigen and alpha-fetoprotein.

Thirteen of 16 patients with primary cancer of the liver were heavy alcoholics. Fifty per cent of them had positive alpha-fetoprotein and 25% had HB-Ag in their blood. The association of alcoholism with cancer of the liver is thus very striking and hence alcohol should be proclaimed as a carcinogenic substance.

Black or African American↗