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Biomedical subjects

A Loy

Publications and source records attributed to A Loy.

At least 37 records · Page 2Linked to original sources
PubMed1992

Mother-to-child transmission of human immunodeficiency virus type 1: risk of infection and correlates of transmission.

One thousand eight hundred eighty-seven children born to human immunodeficiency virus type 1 (HIV-1) seropositive mothers, including 1045 infants prospectively followed up from birth, were studied. Intravenous drug use was the most frequent maternal risk factor, although the percentage of women infected by sexual contact increased from 5.8% in 1985 to 28.5% in 1990. Of the 551 first children followed up from birth and older than 15 months of age, 101 (18.3%) acquired infection and seroconverted to HIV-1. Another 31 (5.6%) asymptomatic seronegative children showed the presence of viral markers, for an apparent mother-to-offspring transmission rate of 23.9%. Overlapping results were seen in 22 second-born children followed up from birth. Of 59 sibships with definite infection status, when the first child was infected, 14 (40%) of 35 second children were infected, whereas when the first child was not infected, only 2 of 24 (8.3%) second children were infected. Discordance in HIV-1 transmission was found in 1 of 18 pairs of twins. Univariate and multivariate analyses of possible risk factors for HIV-1 transmission performed on the entire population of children and in the cohort of those followed up from birth were basically in agreement in indicating that the development of symptoms in the mother before delivery and breast-feeding (indeed adopted in only 22 infants in whom HIV-1 infection was identified at birth) were significantly and independently associated with a higher transmission rate. In addition, girls were more frequently infected than boys.(ABSTRACT TRUNCATED AT 250 WORDS)

Breast Feeding↗
PubMed1991

Serum concentrations and safety of single daily dosing of amikacin in children undergoing bone marrow transplantation.

The serum concentrations and safety of single daily dosing of amikacin were studied in 16 episodes of fever and granulocytopenia in children undergoing bone marrow transplantation. Amikacin (20 mg/kg) was administered as a 20 min iv infusion once daily for 7 to 19 days; all patients received concomitant therapy with ceftazidime. Peak amikacin concentrations measured immediately after infusion on day 1 and 4 of therapy averaged 72.29 +/- 11.6 mg/l and 74.02 +/- 19.29 mg/l respectively. A slight but statistically significant increase 30 minute post-infusion concentrations was observed in most patients during therapy. Serum amikacin were less than 3 mg/l in all trough samples and within 6 h post-infusion in most patients. A significant increase in serum creatinine was observed in one patient, who was also receiving cyclosporin A. Auditory function was evaluated in 10 patients and showed no changes. Although other drugs were added to cover Gram-positive or fungal pathogens, all patients survived. These data combined with the recent experience of single daily dose amikacin in adults supports further evaluation of novel dosage regimens of aminoglycosides in children.

Adolescent↗
PubMed1991

Measurement of extracellular space in the rabbit AV node.

We used quantitative histochemistry to measure the size of the extracellular space (ESC) in various regions of the rabbit heart. When inulin, sucrose, and sorbitol were used as ECS markers, the ECS of the AV-nodal tissue was found to be, respectively, 2.4, 2.2, and 2.5 times larger than that of left ventricular muscle. Glucose was also measured over a 50-fold serum concentration range as an extracellular marker for AV-nodal tissue, left ventricular muscle, and Purkinje fibers. Measurements with glucose also revealed that the ECS of the AV node was 2.5-2.8 times larger than that of ventricular muscle. In contrast, the ECS of the AV node was the same as that of Purkinje fibers when glucose was used as an extracellular marker. ATP content, measured as an intracellular marker, was similar in both AV-nodal and contractile tissue. Collectively, the data obtained with all extracellular markers indicate that the ECS of the AV-nodal region is approximately 2.5 times larger than that of adjacent contractile tissue. Differences in the size of the ECS in various regions of the heart probably have functional significance and should be considered appropriately during the interpretation of data obtained by biochemical and densitometric approaches.

Acetylcholinesterase↗
PubMed1990

Diabetes and the myo-inositol paradox.

To test the general applicability of the hypothesis that diabetes mellitus causes increased polyol pathway activity, decreased tissue free myo-inositol, and resultant pathological changes in tissues susceptible to the ravages of diabetes, we measured glucose, sorbitol, and myo-inositol with quantitative histochemical techniques in layers of the cornea, the aortic myointima, the cardiac left ventricle and atrioventricular node (AVN), and retina and kidney after 19 days or 2 mo (mildly diabetic non-insulin-treated [MD] and severely diabetic insulin-treated [SD] groups) in the alloxan-induced diabetes model. In the aqueous humor, glucose rose linearly with increased serum glucose, sorbitol was markedly increased in the MD and SD groups, and myo-inositol did not change in any diabetic group. There was no change in glucose or sorbitol in aortic myointima in any group, but myoinositol was decreased in 19-day diabetic rabbits by 26%, unchanged in MD rabbits but paradoxically increased by 60% in SD rabbits. Glucose, sorbitol, and myo-inositol increased in all three corneal layers in SD rabbits but only in epithelium and stroma in 19-day and MD rabbits. AVN glucose and sorbitol did not change in 19-day diabetic, MD, or SD diabetic rabbits. AVN myo-inositol was three times higher than ventricular myo-inositol and did not appear to change in SD rabbits. Retinal pigmented epithelium myo-inositol was decreased 30% in SD rabbits. Glomerular myo-inositol was also decreased, but not significantly, in SD rabbits. We conclude that the paradoxical increase in corneal and aortal myo-inositol raises fundamental questions about the general applicability of the myo-inositol-depletion hypothesis.

Animals↗
PubMed1989

[Reactivation of virus replication during immunosuppressive therapy in children with chronic hepatitis B].

The aim of the present work is to assess whether reactivation of viral replication occurred in children affected by chronic hepatitis undergoing long term immunosuppressive therapy. 123 serum samples belonging to 25 children were retrospectively evaluated for HBV-DNA and HBeAg. Sera were collected prior to and during the protocol treatment (steroids alone or with azathioprine). Presence of HBV-DNA was evaluated by means of molecular hybridization technique, using a radiolabelled probe of cloned HBV-DNA. Sera (100 1) were denatured and transferred into nylon membrane (spot) then prehybridized and hybridized. After washing in stringent conditions, the filter was exposed in autoradiographic cassette with Kodak film XOmat5. Positivity was semiquantitatively evaluated by blackening of the spot. Increase or appearance of HBV-DNA was observed in the sera from 24/25 pts. HBeAg became positive in 4/5 pts previously negative. Obtained data shows reactivation of viral replication during immunosuppressive therapy. Data are especially significant in those cases in which such activity has apparently ceased or not been detected; HBV may be considered as a latent virus.

Azathioprine↗
PubMed1989

[Recurrent Salmonella dublin infections].

A recurrent septicemia in a 8-year old child is reported. Blood and lymphnode tissue cultures permitte the isolation of Salmonella dublin. Despite the in vitro susceptibility of the isolated bacteria and the prolonged antimicrobial therapy, sepsis had a protracted course with relapses.

Child↗
PubMed1988

Pharmacokinetics of teicoplanin in pediatric patients.

The pharmacokinetics of teicoplanin have been studied in 13 pediatric male patients from 2 to 12 years of age. Patients were given a single 3-mg/kg intravenous dose of teicoplanin for prophylaxis. Blood and urine samples were collected for 8 days after administration, and teicoplanin levels were determined by microbiological assay. Pharmacokinetic parameters were estimated from a three-compartment open pharmacokinetic model and from a noncompartmental analysis. Levels in plasma 1 h after the administration averaged 14.8 mg/liter. The half-lives of the two distribution phases were 1.3 and 9.7 h. The half-life of the terminal phase averaged 57.9 h, with similar estimates obtained from the noncompartmental analysis and from data from urine. The volume of distribution of the central compartment was 0.15 liter/kg, whereas the volume of distribution at steady state and during the elimination phase were 0.80 and 1.25 liters/kg. The total teicoplanin clearance averaged 14.8 ml/h per kg, with renal clearance accounting for about 60% of the total. The average cumulative recovery of teicoplanin in urine over 8 days was 59% of the dose, similar to the value obtained in adult volunteers. There was no significant linear correlation between elimination half-life and age. Preliminary data after repeated administration support the reliability of the model used and the validity of the mean estimated parameters. There were no local or systemic adverse reactions to teicoplanin.

Analysis of Variance↗
PubMed1986

[Cefotiam, a new cephalosporin. Microbiological research, preliminary evaluation of its effect on phagocytosis and clinical multicenter research].

After a brief review of the data on cefotiam in the literature the report presents the results of microbiological research, a preliminary study into the drug's possible actions on phagocytosis and a polycentric clinical study of 93 cases of broncho-pleuro-pulmonary pathology and one sinusitis of the jaw. In vitro cefotiam was found to have an excellent inhibitory effect on gram positive and gram negative bacteria with MICs50 and 90 respectively 0.2 and 0.8 mcg/ml V. Staph. aureus, Str. pyogenes. E. Coli, K. pneumoniae and Pr. mirabilis. A dose-dependent increase in phagocytosis was noted. The clinical response was excellent with 90.43% (88/94) of the cases achieving clinical and radiological cure or very much improved. Cefotiam was very well tolerated with the appearance of 2/94 skin rashes (2.12%). The liver and kidney parameters showed no change at the end of treatment. No increase in enzymuria was noted during treatment with cefotiam.

Absorption↗
PubMed1985

Hyperdiploidy of 54 chromosomes with double Ph1 chromosome in lymphoid chronic myelocytic leukemic blast crisis.

Cytogenetic analysis of bone marrow cells in a 40-year-old man revealed a mosaic of two cell lines during blast crisis: one diploid with typical Ph1 chromosome (46 XY Ph1) and one with hyperdiploidy of 54 chromosomes with double Ph1 chromosome, trisomy 4, 6, 8, 18, 21 and duplication of the sex chromosomes X and Y. Immunological characterization showed common acute lymphoblastic leukemia antigen in 90% of the blasts. In spite of intensive chemotherapy the patient died in a third blast crisis 15 months after the first blast crisis, 3 months after successfully treated central nervous system relapse.

Adult↗
PubMed1984

A spell of chicken-pox on a cancer patients' ward.

Second episodes of varicella after a definite primary exposure to chicken-pox are well known in immunosuppressed children. We report an outbreak in adult cancer patients. This observation suggests that there is also a higher risk of varicella infection in immunosuppressed adults. As there is a trend for a pronounced severity of chicken-pox in patients receiving anticancer drugs or suffering from immunosuppressive diseases, the prophylactic use of varicella zoster immune globulin in adult patients has to be discussed, especially as positive experiences with children were recently gained. Following manifestation, therapy with systemic aciclovir seems to be effective.

Adult↗
PubMedDate not supplied

[Autologous bone marrow transplantation in children. Use of parenteral nutrition].

Children undergoing ABMT, a procedure which entails massive doses of chemotherapy along with total-body irradiation, are candidate to develop severe gastrointestinal toxicity and prolonged anorexia requiring administration of Parenteral Nutrition (PN) for variable periods. We report a series of 35 consecutive children affected by malignancies who underwent 37 courses of PN after ablative therapy followed by ABMT. Age ranged from 8 months to 17 years; 16 were females, 19 males. There were 23 cases of neuroblastoma, 5 of Wilms' tumor, 3 of acute myelogenous leukemia, 2 of Ewing's sarcoma, 1 case each of rhabdomyosarcoma and acute lymphoblastic leukemia. All patients developed severe neutropenia for 9-42 days (median 18 d). Fever occurred in all patients; sepsis was documented in 10. Duration of PN ranged from 10 to 64 days (23 +/- 9; mean +/- SD). PN solution, containing crystalline L-Aminoacids (8.5%) mixed with 33% glucose, minerals, trace elements and vitamins provided for children a caloric intake of 49.8 +/- 17.3 Kcal/Kg/day with a nitrogen intake of 0.26 +/- 0.27 g/Kg/day. Nutritional assessment, utilizing percent ideal body weight, serum protein electrophoresis, C3, pseudocholinesterase and fibrinogen, was performed at the beginning and at the completion of each course of PN. Mean percent ideal body weight was 95.8 before PN, 98.5 on last day of PN (p less than 0.0005). Other parameters did not change significantly. No metabolic complication nor severe electrolyte imbalance were observed except for 5 patients who developed hypokalemia in coincidence with administration of Amphotericin B.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗