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Biomedical subjects

T Thompson

Publications and source records attributed to T Thompson.

At least 163 records · Page 9Linked to original sources
PubMed1985

Mapping of DNase I-hypersensitive sites in the 5' and 3' long terminal repeats of integrated moloney murine leukemia virus proviral DNA.

The chromatin state of integrated Moloney murine leukemia virus (M-MuLV) proviral DNA was investigated. Nuclei from M-MuLV-infected mouse NIH 3T3 cells were digested with limited amounts of DNase I, and hypersensitive (HS) sites were mapped by the indirect end labeling technique. Particular emphasis was placed on the 5' long terminal repeat (LTR), since viral transcription initiates there. M-MuLV proviral DNA showed two strong DNase I-HS sites in the 5' LTR, one coincident with the transcription initiation (cap) site and the other with the transcriptional enhancers. Two weaker DNase I-HS sites were also detected in internal proviral DNA. The 3' LTR also showed a strong HS site in the region of the enhancers, but an HS site at the cap site of the 3' LTR was not detected. Thus, the chromatin configurations of the 5' and 3' LTRs of integrated M-MuLV proviruses appear to be different. The chromatin configuration of M-MuLV proviruses which contain LTR insertions of polyomavirus enhancer sequences was also studied. The 5' LTR of M-MuLV proviruses containing polyoma enhancer sequences substituted for the M-MuLV enhancers showed two strong HS sites, one in the polyoma sequences and one at the cap site. The 5' LTR of M-MuLV proviruses containing polyoma enhancer sequences inserted into the wild-type M-MuLV LTR between the cap site and the M-MuLV enhancers showed three HS sites. Two HS sites corresponded to those of the wild-type M-MuLV LTR, whereas the third mapped to the inserted polyoma sequences. The HS site associated with the inserted polyoma sequences was considerably stronger than the M-MuLV-associated HS sites.

Animals↗
PubMed1984

Interval and ratio reinforcement contingencies as determinants of methadone's effects.

The effects of methadone hydrochloride on lever pressing rats maintained under multiple fixed-interval and fixed-ratio, or multiple variable-interval and variable-ratio reinforcement schedules equated for reinforcement density were examined. Under a multiple fixed-interval, fixed-ratio schedule overall response rate was decreased during both components but was most affected under the ratio schedule. Response rate decreases were due primarily to changes in running rate rather than pause time. Under a multiple variable-interval, variable-ratio schedule, overall response rate was also decreased by methadone, with the greatest decrease again occurring during the ratio schedule. These schedule-specific methadone effects are not due to differences in reinforcement frequency. Evidence for rate-dependency with methadone is not consistent across subjects.

Animals↗
PubMed1984

Management of intracardiac fungal masses in premature infants.

Intracardiac fungal masses can develop following episodes of candidemia in premature infants with indwelling right atrial lines. We report the first premortem diagnosis and successful surgical removal of Candida-containing intracardiac masses in three premature infants. All had central venous lines and had been on systemic antibiotics prior to the development of candidemia. By echocardiography, two were pedunculated, solitary masses within the right atrium. Amphotericin B and 5-flucytosine for 21 to 42 days controlled the Candida sepsis, but the masses became increasingly mobile and did not decrease in size. In the third infant, large, irregular masses extended from the right atrium to the main pulmonary artery, and surgical removal was recommended 4 days after the start of antifungal therapy. In all three patients, the masses were nearly the size of the main pulmonary artery and presumably contained viable organisms. Removal was accomplished with the aid of cardiopulmonary bypass for two and inflow stasis for one infant weighing only 1,300 gm. The masses were filled with viable Candida organisms. All patients tolerated the operation well and have been followed up for 1 to 3.6 years without evidence of recurrent Candida infection. The case of a fourth infant, weighing 1,320 gm, is also reported. This infant had a bacteria-containing intra-atrial mass, which was removed successfully with the aid of inflow occlusion. This report documents the following points: (1) Echocardiography provides a noninvasive method of diagnosing the development of intracardiac masses and should be performed in infants who have had candidemia and a central venous line. (2) Prolonged systemic antifungal therapy does not appear to either sterilize or promote regression of the masses. (3) The masses can be safely removed, even in the premature infant, with either inflow stasis or cardiopulmonary bypass. (4) Surgical removal is an effective component of the treatment of infection in these infants.

Amphotericin B↗
PubMed1983

Perinatal stress: a study of factors linked to the risk of parenting problems.

Infants who are born preterm are at high risk for subsequent maltreatment. This study examines the relationship between family functioning, infant morbidity, parents' experience following their infant's admission to a neonatal intensive care unit, and postdischarge risk of parenting problems. For the sample as a whole, family factors emerged as the best predictors of outcome.

Anxiety↗
PubMed1983

Studies of rhenium carboxylates as antitumor agents. Part II. Antitumor studies of bis (mu-propionato) diaquotetrabromodirhenium (III) in tumor-bearing mice.

The neutral, dimeric complexes of rhenium, bis (mu-carboxalato)-diaquotetrahalodirhenium (III) (carboxalato = acetato, propionato, or butyrato and halo = chloro or bromo), were synthesized and survival studies were done on mice bearing P-388 leukemia or B-16 melanoma. The complex bis (mu-propionato) diaquotetrabromodirhenium (III) proved to be the most effective in increasing the life span of the mice. The complex showed some activity against B-16, but virtually none against P-388. The complexes are all quite non-toxic.

Animals↗
PubMed1982

Measurement of the fasting urinary hydroxyproline: creatinine ratio in normal adults and its variation with age and sex.

Conditions for the determination of the fasting urinary hydroxyproline: creatinine ratio (OHPr: Cr ratio) have been examined, using a resin-catalysed hydrolysis and automated colorimetric procedure for the determination of hydroxyproline. Feeding experiments with gelatin showed that hydroxyproline is rapidly absorbed and excreted in the urine and that a 12-hour (overnight) fast is sufficient to ensure correct and reproducible fasting OHPr: Cr ratios. The mean fasting OHPr: Cr ratio decreased slightly with increasing age in both men and premenopausal women but there was no significant difference between the sexes. There was, however, a significant increase in the mean ratio in postmenopausal women. The normal range of fasting OHPr: Cr ratios for men and premenopausal women was found to be 0.003--0.015.

Adolescent↗
PubMed1981

Immune thrombocytopenia in severe neonatal infections.

Thrombocytopenia occurs frequently in newborn infants with sepsis, but the exact mechanism remains obscure in those infants who do not have evidence of disseminated intravascular coagulation. Since recent work has suggested a possible immune mechanism for thrombocytopenia observed in adults with sepsis, we have investigated the role of platelet-associated immunoglobulin in severe neonatal infections. To detect PAIgG we use a method employing protein A and peroxidase-antiperoxidase as a labeled antibody. PAIgG was quantitated by phase contrast microscopy and expressed as a reactive index. Our control group included 16 normal newborn infants whose mean RI was 0.65 +/- 0.01 SE. In addition to the control group, five infants with nonimmune thrombocytopenia were included; their mean RI was 0.66 +/- 0.01 SE. Seventeen newborn infants with severe infections were assayed for PAIgG. Eight of nine infants with bacterial infections had increased RI, with a mean of 1.16 +/- 0.03 SE (P less than 0.01). Six of the eight infants with viral infections had elevated RI, with a mean of 1.23 +/- 0.03 SE (P less than 0.01). These findings suggest that an immune mechanism may be involved in the thrombocytopenia of severe neonatal infection.

Bacterial Infections↗
PubMed1981

A cojoint, operant model for assisting profoundly behaviorally disordered adolescents.

This article describes a community treatment program established in a semirural New Mexico community that was cojointly administered by the local school district, university and mental health center in order to facilitate the adoption of personal and academic skills among profoundly, behaviorally disordered adolescents. The treatment, a model classroom, is staffed by a fulltime teacher and a full-time psychologist whose roles are differentiated primarily by the ways and type of operant behavior they reinforce. This cojoint operant model for assisting profoundly behaviorally disordered adolescents was successful in facilitating the overall adjustment of eight adolescents in one academic year, as evidenced results of a behavior rating scale, projective testing, and parents' checklist and individual interviews. Theoretical bases and procedures for implementing the model are described, and recommendations for future programs serving emotionally disturbed adolescents are proposed.

Adolescent↗