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Biomedical subjects

M Samuel

Publications and source records attributed to M Samuel.

At least 37 records · Page 2Linked to original sources
PubMed1987

Sexual practices and risk of infection by the human immunodeficiency virus. The San Francisco Men's Health Study.

The San Francisco Men's Health Study is a prospective study of the epidemiology and natural history of the acquired immunodeficiency syndrome in a cohort of 1034 single men, 25 to 54 years of age, recruited by multistage probability sampling. At entry, June 1984 through January 1985, the seropositivity rate for human immunodeficiency virus (HIV) infection among homosexual/bisexual study participants was 48.5%. No heterosexual participants were HIV seropositive. Among homosexual/bisexual men reporting no male sexual partners in the two years before entry into the study, seropositivity was 17.6%. For those reporting more than 50 partners, seropositivity was 70.8%. Only receptive anal/genital contact had a significantly elevated risk of HIV infection. Douching was the only ancillary sexual practice that contributed significantly to risk of infection.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Characteristics of long-term human epithelial cell cultures derived from normal human fetal kidney.

Epithelial cell cultures were prepared from normal human fetal kidney and established in long-term culture. The growth characteristics and production of keratin, and alkaline phosphatase (AP) and gamma-glutamyl transpeptidase (GGT) activities were compared in a modified minimal essential medium (mMEM), D-valine-containing modified alpha-MEM (mALPHA) and L-valine mALPHA. The mean number of cumulative population doublings (CPDL) was significantly (P less than 0.001) enhanced with the L-valine mALPHA (40.8 CPDL) over that achievable in mMEM (14.2 CPDL) or D-valine mALPHA (18.3 CPDL) media. In all three media, greater than 95% of the cells in culture produced keratin throughout the life span of these cultures. Surface-associated fibronectin was absent in these cell cultures. AP and GGT activities increased as a function of subpassage and time in culture, with the greatest activity in the L-valine mALPHA. The expression of these renal cell-associated functions suggests that these cells in culture are proximal tubule epithelial cells. The conditions and procedures described in this paper can provide a human kidney epithelial cell culture system for studying human renal function, metabolism, cytotoxicity, genotoxicity, and transformation.

Alkaline Phosphatase↗
PubMed1987

The San Francisco Men's Health Study: III. Reduction in human immunodeficiency virus transmission among homosexual/bisexual men, 1982-86.

The prevalence and incidence of infection by the human immunodeficiency virus (HIV) has been under study in a cohort of 1,034 single men recruited by area probability sampling from a six kilometer square area of San Francisco where the epidemic of acquired immunodeficiency syndrome (AIDS) has been most severe. Prevalence of infection among homosexual/bisexual study subjects increased from an estimated 22.8 per cent during the last half of 1982 to 48.6 per cent during the period July through December 1984. During three subsequent six-month periods, prevalence remained stable at approximately 50 per cent. Annual infection rates, measured by seroconversion among seronegative study subjects, decreased from an estimated 18.4 per cent per year from 1982 to 1984, to 5.4 and 3.1 per cent during the first and second halves of 1985, and to 4.2 per cent during the first six months of 1986. These declines were associated with reductions of 60 per cent or more in the prevalence of high-risk sexual practices associated with both acquiring and disseminating infection by the human immunodeficiency virus.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Adjuvant radiotherapy for stage I, grade 2 endometrial adenocarcinoma and adenoacanthoma with limited myometrial invasion.

All cases of endometrial adenocarcinoma from January 1970 to December 1980 treated at the Geisinger Medical Center were reviewed retrospectively. One hundred eighty-eight cases of stage I grade 2 adenocarcinoma of favorable histologic subtype (adenocarcinoma, adenoacanthoma) and limited myometrial invasion (less than one-third of the myometrium) were identified. Surgery and adjuvant radiotherapy was used in 136 cases, and 52 cases were treated with surgery alone. There was no statistically significant difference between the two groups in menopausal status, parity, exogenous estrogen, obesity, hypertension, diabetes, or uterine size. Five-year survival for the surgery and radiotherapy group was 94% (128 of 136), and the recurrence rate was 2.2% (three of 136). The five-year survival for the surgery-alone group was 98% (51 of 52), and the recurrence rate was 1.9% (one of 52). There was no statistically significant difference in five-year survival or recurrence between the two groups. This study suggests that surgery alone is adequate treatment for stage I grade 2 adenocarcinoma of favorable histologic subtype and limited myometrial invasion. This study also shows a possible benefit in the combined use of histologic subtype, grade, and myometrial invasion as prognostic indicators and as guides for adjuvant radiotherapy.

Adenocarcinoma↗
PubMed1987

School health--preparation of teacher for health education.

In India where the school children form a significant and important segment of the population, the health needs are so great, that a well planned "School Health Programme" is absolutely necessary. Teacher preparation for health education has its rightful place in it.

Adult↗
PubMed1986

Metabolism of 5-hydroxyicosatetraenoate by human neutrophils: production of a novel omega-oxidized derivative.

Human neutrophils incorporated 5-hydroxy-E,Z,Z,Z-6,8,11,14-eicosatetraenoic acid (5-HETE) into cellular triglyceride and phospholipid. They also metabolized 5-HETE into a novel, extracellularly released derivative, 5,20-dihydroxy-E,Z,Z,Z-6,8,11,14-eicosatetraenoic acid (5,20-diHETE). 5,20-diHETE formation predominated at higher substrate concentrations and longer incubation intervals. In the absence of added 5-HETE, 1 X 10(8) neutrophils stimulated with 20 microM ionophore A23187 produced up to 243 ng of 5,20-diHETE, indicating that both endogenously formed and exogenously added substrate could be oxidized at carbon 20. 5,20-diHETE was about 10- to 100-fold weaker than 5-HETE in enhancing human neutrophil degranulation responses to platelet-activating factor. omega-Oxidation appears to be a general enzymatic mechanism for inactivation of arachidonic acid metabolites.

Calcimycin↗
PubMed1986

A method for isolating large numbers of viable disaggregated cells from various human tissues for cell culture establishment.

A method is described for the isolation of large numbers of viable disaggregated cells from human tissues. This method combined the mechanical action of a Stomacher Model 80 Lab Blender, 0.1 mg/ml trypsin or 0.5 mg/ml collagenase, and 0.1 mM [ethylene bis(oxyethylenenitrolo)]-tetraacetic acid (EGTA). Tissue (0.2 to 1.0 g) obtained from human fetal intestine, kidney, liver, lung, and skin were separately minced into approximately 1-mm3 pieces. The pieces were placed in a sterile bag containing 60 ml of calcium- magnesium-free phosphate buffered saline, the appropriate enzyme (0.1 mg/ml trypsin or 0.5 mg/ml collagenase) plus 0.1 mM EGTA, and 0.1% methylcellulose. The bag was then placed into the blender and mixed at a low speed for 3 to 20 min at room temperature. After a single cell suspension was observed by phase contrast microscopy, 10 ml of bovine calf serum was added to the cell suspension to inactivate the proteolytic enzymes. At this time 130 ml of cold Hanks' balanced salts solution containing 5% bovine calf serum was added and the entire cell suspension passed through a tissue sieve (100 mesh, 140 micron) and the cells collected by centrifugation. These cells were then resuspended into the appropriate culture medium. In comparison to other methods for establishment of cell cultures from human tissues, the method described requires shorter incubation times with relatively low concentrations of proteolytic enzymes, and yields two- to three-fold greater number of cells per tissue with 86 to 93% viability. Also, depending on the cell type, 50 to 75% of the isolated cells attached to the culture vessel within 24 h. Variation of the time and concentration of digestive enzymes can be used to select different cell types for culture.

Cell Aggregation↗
PubMed1986

Desorption chemical ionization mass spectrometry of 1-O-alkyl-2-O-acetyl-sn-glycero-3-phosphocholines and analogues.

Ammonia desorption chemical ionization of ether-linked phospholipids of the type 1-O-alkyl-2-O-acetyl-sn-glycero-3-phosphocholine (platelet-activating factors) and a series of analogues revealed a systematic fragmentation pattern that is characteristic for these compounds. The predominant ions included the protonated molecular ion and a series of fragments derived from the molecular ion having the following nominal mass losses: MH-14, MH-42, MH-59, and MH-183. Deuterated ammonia was used to elucidate the nature of several fragments. In addition, desorption chemical ionization was used to quantitate 1-O-hexadecyl-2-O-acetyl-sn-glycero-3-phosphocholine at the nanogram/sample level.

Ammonia↗
PubMed1985

PUVA therapy for psoriasis: choosing a suitable régime.

Three age- and sex-matched groups of 30 patients with chronic plaque psoriasis were treated by photochemotherapy (PUVA). Groups I and II received routine maintenance PUVA therapy at different intervals and Group III had no maintenance treatment. The remission time after the clearance treatment with PUVA is compared with the total cumulative dose of long wave ultraviolet light (UVA). A lower mean dose of UVA (51.0 +/- 1.7 joules/cm(2)) in Group III (no maintenance PUVA) achieved a comparable remission period to that after larger cumulative doses following routine maintenance therapy (87.8 +/- 4.9 and 77.0 +/- 4.1 joules/cm(2) in Groups I and II).

Adolescent↗
PubMed1979

Virus-specific and anticellular antibodies in molluscum contagiosum.

Sera from patients with molluscum contagiosum showed a higher incidence of anticellular and fibrillar anticellular antibodies of IgM class as compared to sera from control subjects. Most patients with anticellular IgM antibodies also had molluscum contagiosum virus-specific antibodies. In a comparative study, there was a higher incidence of anticellular IgM antibodies to normal human epidermis and fibrillar anticellular IgM antibodies in molluscum contagiosum than in warts of psoriasis. The incidence in psoriasis was lower than warts and was similar to that found in control subjects.

Adolescent↗
PubMedDate not supplied

Pediatric jaw fractures: indications for open reduction.

Jaw fractures in children are generally managed without major surgical intervention. Closed reduction usually is sufficient to restore normal anatomy and function. The one inviolate principle is early treatment. During the past three years, four pediatric jaw fractures that required open reduction were treated. This mode of treatment was necessitated by the limitations imposed by pediatric dental anatomy and by the type of fractures encountered. In at least 24 months of follow-up, no dental problems have been seen.

Child, Preschool↗