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Biomedical subjects

T D Nguyen

Publications and source records attributed to T D Nguyen.

At least 163 records · Page 9Linked to original sources
PubMed1981

Artifact in client satisfaction assessment: experience in community mental health settings.

Artifact in client satisfaction assessment is discussed and the results of a study of three factors thought to mediate client satisfaction ratings; (a) general life satisfaction, (b) mode of administration, and (c) psychological symptomatology, are reported. A standard client satisfaction questionnaire (CSQ) was modified to yield parallel forms and was administered orally and in writing to 92 clients in two mental health day treatment programs. Satisfaction ratings obtained from these clients were quite similar to out-patient ratings obtained in previous studies conducted in this setting and using the same measures. Oral administration of the CSQ produced 10% higher satisfaction ratings than written administration (p less than .05) and less missing data (p less than .01). Satisfaction ratings were also obtained using a simple graphic instrument. Graphic ratings were comparable to CSQ ratings. Satisfaction with life in general and level of psychiatric symptoms together accounted for 25% of CSQ variance. The implication of these findings for future client satisfaction research is discussed.

California↗
PubMed1981

[Dysgerminoma of the ovary: a study of 13 cases (author's transl)].

Thirteen cases of primary ovarian seminoma have been referred to the Claudius Regaud Cancer Center during the last 2 decades, patients' ages ranging form 10 to 41 years with a peak in the 20's. Two patients were treated by surgery as definitive therapy, the others underwent combined radiation therapy (dose range 25 to 45 Gy) following surgical excision. The 2 patients treated by surgery alone had pelvic recurrences, whereas only 2 local failures appeared in the group treated by surgery and radiotherapy. Ten patients are asymptomatic and clinically free of disease after a mean follow-up of 3.5 years, the mean survival time of the series being 6 years. Because of the generally improved prognosis, surgical oophoropexy is recommended before radiotherapy.

Adolescent↗
PubMed1979

Sensitivity of drosophila mutants to chemical carcinogens.

7 single-mutant and five double-mutant strains of Drosophila melanogaster were tested for their relative sensitivity to the chemical carcinogens: 1-acetylaminofluorene, benzo(alpha)pyrene, N-methyl-N'-nitro-N-nitrosoguanidine, 4-nitro quinoline-1-oxide and aflatoxin B1. Among the single mutants, mei-9a, mei-41D5 and mus(1)104D1 are hypersensitive to all 5 chemicals, whereas mus(1)107D1 is hypersensitive only to 4-nitroquinoline-1-oxide and is slightly sensitive to benzo(alpha)pyrene. The mei-9a mei-41D5 double-mutant is the most sensitive of 5 tested double-mutants which carry the mei-9a allele. When treated with 0.025 mM benzo(alpha)pyrene this double-mutant produces significantly more sex-linked recessive lethals and dominant lethals than does the control. Analysis of double-mutants reveals that the mei-9+ product functions in a different repair pathway of methyl methanesulfonate-induced damage than do the normal products of the mus(1)103, mus(1)104 and mus(1)107 loci. Our findings suggest that the sensitivity of Drosophila repair-deficient mutants could be exploited in screening for potential mutagens and carcinogens.

4-Nitroquinoline-1-oxide↗
PubMed1976

Genetic controls of meiotic recombination and somatic DNA metabolism in Drosophila melanogaster.

Recombination-defective meiotic mutants and mutagen-sensitive mutants of D. melanogaster have been examined for their effects on meiotic chromosome behavior, sensitivity to killing by mutagens, somatic chromosome integrity, and DNA repair processes. Several loci have been identified that specify functions that are necessary for both meiotic recombination and DNA repair processes, whereas mutants at combination and DNA repair processes, whereas mutants at other loci appear to be defective in only one pathway of DNA processing.

Animals↗
PubMed1976

Isolation and characterization of X-linked mutants of Drosophila melanogaster which are sensitive to mutagens.

Thirteen X-linked mutants have been isolated in Drosophila melanogaster which render male and homozygous female larvae sensitive to the mutagen methyl methanesulfonate. Their characterization and preliminary assignment to functional groups is described. Four of these mutants are alleles of mei-41 (Baker and Carpenter 1972). Like previously isolated alleles of this locus, these mutants reduce fertility and increase loss and nondisjunction of the X-chromosome in homozygous females. The remaining mutants have been tentatively assigned to six functional groups (two mutants to the mus(1)101 locus, two to mus(1)102 , two to mus(1)103, and one each to mus(1)104, mus(1)105 , and mus(1)106). Several of the complementation groups can be distinguished on the basis of nondisjunction and cross sensitivity to mutagens. Females homozygous for the mei-41, mus(1)101 and mus(1)102 mutants exhibit elevated levels of nondisjunction. Mutants belonging to complementation groups mei-41, mus(1)101, and mus(1)104 are sensitive to nitrogen mustard (HN2) in addition to their MMS sensitivity. Among these mutants there is currently a direct correlation between sensitivity to HN2, sensitivity to 2-acetylaminofluorene and a deficiency in post-replication repair ( Boyd and Setlow 1976). Only the mei-41 mutants are hypersensitive to UV radiation, although several of the mutants exhibit sensitivity to gamma-rays. Semidominance is observed in female larvae of the mei-41, mus(1)104, and mus(1)103 mutants after exposure to high concentrations of MMS. The properties of the mutants generally conform to a pattern which has been established for related mutants in yeast. Additional properties of these mutants are summarized in Table 9.

Alleles↗
PubMedDate not supplied

Single dose artemisinin-mefloquine treatment for acute uncomplicated falciparum malaria.

For the treatment of patients with acute falciparum malaria, the combination of artemisinin as a single dose with a single dose of mefloquine was studied in 4 separate prospective trials, comprising 405 adults and 139 children with uncomplicated falciparum malaria in 2 in-patient and 2 rural out-patient studies in Viet Nam. Adults received oral artemisinin and children artemisinin suppositories. Randomized comparative treatment schedules were: artemisinin alone for 5 d, mefloquine-sulfadoxine-pyrimethamine (MSP), or quinine plus sulfadoxine-pyrimethamine (SP). Parasite clearance times (PCT) were rapid for artemisinin treated inpatients (90%: 14.8-20.4 h) but also for patients receiving MSP (PCT 90%: 18.0 h) and quinine (PCT 90%: 22.5 h). The recrudescence rate (RI) during a 28 d follow-up period among the patients given artemisinin plus mefloquine was 15% in the adult in-patients and zero in the adult and children out-patients. RI in the artemisinin 5 d treatment group was 33.3%; among those given artemisinin plus SP it was 47.3% in in-patients and in out-patients 46.1%. In the MSP treated out-patients RI was 1.5% in adults and zero in children. Artemisinin as a single dose (oral in adults and as a suppository in children) in combination with mefloquine was effective in rapidly lowering parasitaemia and in preventing recrudescence in hospital in-patients and in out-patients attending a rural health clinic. MSP alone as a single dose also rapidly reduced parasitaemia (but not as quickly as the artemisinin-mefloquine combination in out-patient children) and prevented recrudescence.

Acute Disease↗
PubMedDate not supplied

Peptide T from human immunodeficiency virus envelope does not interact with hepatic, intestinal and colonic vasoactive intestinal peptide (VIP) receptors.

Acquired immunodeficiency syndrome (AIDS) is initiated by the attachment of the human immunodeficiency virus (HIV) to specific target cells. An octapeptide sequence contained within the envelope of HIV, peptide T, mediates the viral binding. Since there is a considerable structural homology between peptide T and VIP, it has been proposed that the VIP receptor may be the naturally occurring protein which provides the corresponding cellular attachment site. In three different models (rat intestinal epithelial cell membranes, rat liver plasma membranes and human colonic cells), we document the lack of interaction between peptide T and the VIP receptor. These observations would also exclude any pathophysiologic effect caused by the crossreactivity of peptide T or its analogues and these VIP receptors.

Adenocarcinoma↗
PubMedDate not supplied

Vasoactive intestinal peptide receptor on liver plasma membranes: solubilization and cross-linking.

The hepatic receptor for VIP was solubilized from rat liver plasma membranes with 1.4% digitonin and shown to conserve its ability to bind to the ligand. This solubilized receptor demonstrated the high affinity and specificity for VIP (KD approximately 1 nM, binding preference: VIP greater than PHI greater than secretin greater than thymosin alpha 1) which were observed with the nonsolubilized VIP receptor on intact liver plasma membranes. 125I-VIP was next cross-linked to either the solubilized or nonsolubilized receptor using disuccinimido suberate or disuccinimido dithiobis(propionate), and the resulting complexes analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by autoradiography. A broad autoradiographic band which demonstrated a high affinity for VIP was identified at Mr 56,000 (53,000 in the absence of the reducing agent dithiothreitol) for both the solubilized and nonsolubilized receptors. We have thus been able to solubilize from rat liver plasma membranes a receptor with high affinity and specificity for VIP, and confirmed its structural similarity with the native VIP receptor in nonsolubilized membranes using cross-linking techniques.

Animals↗
PubMedDate not supplied

[Non-metastatic advanced non-small cell lung carcinoma: systemic high-dose brachytherapy following curative external radiotherapy].

PURPOSE: To analyse retrospectively the local control, overall survival and immediate and long-term tolerance after a radiotherapy delivered with a curative intent systematically including a high-dose rate brachytherapy. PATIENTS AND METHODS: From January 1993 to January 1995, 50 patients (45 males-five females, median age: 61) with non-small cell lung cancers, inoperable for tumour reasons, non-metastatic, were included in the protocol. Following external radiotherapy (55-65 Gy conventional fractionation), all the patients received high-dose rate brachytherapy delivering 14 to 24 Gy using fractions of 7 Gy. RESULTS: Immediate tolerance was good. Two months after the end of the treatment, five patients suffered from massive haemorrhages and three others experienced a mucosal necrosis (two tracheal sites). Tumour response was observed endoscopically in 88% of the cases (38/50) and was complete in 38%. Median survival of complete responders was 15 months. In the mean follow-up period of 24 months, five patients were still alive with no evidence of disease (median survival: 30 months). Most of the patients died from distant metastases (33/50: 66%). CONCLUSION: Systematic use of endoluminal high-dose rate brachytherapy in addition to external radiotherapy did not improve survival. The gain in the local control rate was counteracted by an increase in haemorrhages and mucosal necroses. Improving techniques and dosimetry, and combining different methods which have proved their efficiency, should result in improvements in survival. Quality of life would be part of the analysed parameters in any future study.

Adult↗
PubMedDate not supplied

Association between leprosy and immunoglobulin allotypes: Gm-A2m and Km frequencies in Vietnamese.

The relationship between immunoglobulin allotypes and leprosy was studied in 91 unrelated patients and 100 healthy controls from Vietnam. Twenty Vietnamese patients with tuberculosis were also typed for the Gm, A2m and Km allotypes. The results were compared with those from the healthy controls. No significant association was found for the allotypes G1m(z,a,x,f) G2m(n), G3m(g,b), A2m(1,2) and Km(1,3) between the two groups of patients and the controls. Heterogeneity in the distribution of G2m(n), G3m(b), A2m(2) and Km(3) was found when 60 polar-lepromatous (LL) patients and 27 borderline-tuberculoid (BT) patients were separated out of the 91 leprosy patients. In the LL patients there appeared to be a significantly higher frequency of G2m(n), G3m(b) and A2m(2) in comparison with the BT patients (P less than 0.05). A significantly lower frequency of Km(3) was found in the LL patients in comparison with the healthy control group (P less than 0.05). The frequencies of the Gm-A2m haplotypes and of the occurrence of the Km(1) and Km(3) in the Vietnamese population were calculated on the basis of the results in the 100 samples of healthy controls. The main haplotype is Gmaf;n;b (frequency 0.676), occurring with A2m1 (0.200), as well as with A2m2 (0.476).

Gene Frequency↗
PubMedDate not supplied

[Allergy has no age].

Even though allergic reactions to local anesthesia are rare and even more so among elderly people, the present case demonstrates that a medication can be tolerated for a significant period of time before causing an accident. This illustrative case details the true nature of complications observed following local anesthesia and suggests a way of approaching the same to arrive at a definitive diagnosis. This method consists of a rigorous analysis of the clinical manifestations and allergologic testing. Local anesthesia is indispensable for both the dentist and the patient and anyone with allergies is at risk at being allergic to general anesthesia as well.

Aged↗