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Biomedical subjects

T Lee

Publications and source records attributed to T Lee.

At least 361 records · Page 20Linked to original sources
PubMed1983

Immunoglobulin allotype markers in gluten-sensitive enteropathy.

Immunoglobulin allotype markers and HLA-A, HLA-B, and HLA-DR locus antigens were determined in 30 White patients with gluten-sensitive enteropathy and 30 controls matched for age, ethnic background, and geographic origin. All patients lacking HLA-B8 and HLA-DR3 had the IgG (Gm) immunoglobulin heavy-chain phenotype Gm (f;n;b). Thus, in addition to major histocompatibility locus genes, it appears that genes linked to the immunoglobulin heavy-chain allotype locus on chromosome 14 may influence susceptibility in gluten-sensitive enteropathy.

Adolescent↗
PubMed1983

A simple estimated fetal weight equation based on real-time ultrasound measurements of fetuses less than thirty-four weeks' gestation.

Based on ultrasonographic mensuration, a number of equations have previously been devised for the purpose of estimating fetal weights. The objective of this study was to develop a mathematical equation that is simple, accurate, and easy to use when applied to preterm or low-birth weight fetuses (less than 2,500 gm). Real-time ultrasound measurements of fetal biparietal diameters (BPDs) and abdominal circumferences (ACs) were obtained in 62 pregnant women within one week of premature delivery. Mean gestational age and mean birth weight +/- SD for this study group of neonates were 28.5 +/- 3.5 weeks and 1,135 +/- 343 gm, respectively. With the aid of computer analysis, a simple regression equation was derived: EFW = (BPD x AC x 9.337) - 229. When predicted estimated fetal weight (EFW) was compared with actual birth weight (ABW), multiple regression analysis demonstrated a correlation coefficient (R) of 0.957. Preliminary results on 19 patients of a prospective study showed an absolute mean difference between the computed EFWs and the ABWs to be within 7.0% of ABW (70 gm/kg of ABW). The standard deviation of the difference was 9.3% of ABW (93 gm/kg of ABW). Based on these data, this simple equation appears to be clinically reliable and easy to use when estimating weights of preterm or low-birth weight fetuses of less than 2,500 gm.

Birth Weight↗
PubMed1983

Impact of inter-physician communication on the effectiveness of medical consultations.

To evaluate the impact of the inter-physician communication on the effectiveness of consultations, consultations performed by general and subspecialty medical consultation services for one week both early and late in the academic year were prospectively evaluated. Physicians commonly requested consultations to get advice on diagnosis (56 percent), advice on management (37 percent), or assistance in arranging or performing a procedure or test (20 percent). Despite our very liberal definitions, the requesting physician and the consultant completely disagreed on both the reason for the consultation and the principal clinical issue in 22 (14 percent) of 156 consultations. Consultants were twice as likely as the requesting physicians to rate consultations as crucial for management (35 percent versus 18 percent, p = 0.001) because they gave significantly higher ratings when they and the requesting physicians did not agree on the reasons for consultation. Consultations ordered for very specific purposes, such as assistance in arranging or performing a test, were rated significantly higher by the requesting physicians. It was found that breakdowns in communication are not uncommon in the consultation process and may adversely affect patient care, cost effectiveness, and education.

Boston↗
PubMed1983

Analysis of incision depth following experimental radial keratotomy.

Eight-incision radial keratotomy was performed on a series of cadaver eyes using ultrasonic pachymetry and both metal and diamond blades. There were no statistically significant differences in mean corneal flattening (approximately 9.5 diopters) obtained with either the diamond or metal blades. Short diamond knife incisions produced less flattening that was statistically significant (5.8 diopters). Histologic analysis of incision depth revealed similar results with both the diamond (84%) and metal (86%) blades.

Cadaver↗
PubMed1983

Ten commandments for effective consultations.

If internists are not explicitly instructed in how to perform consultations, the outcome of their consultative efforts may be suboptimal. We suggest that consultations will be more helpful if the following principles are followed: the consultant should determine the question that is being asked, establish the urgency of the consultation, gather primary data, communicate as briefly as appropriate, make specific recommendations, provide contingency plans, understand his own role in the process, offer educational information, communicate recommendations directly to the requesting physician, and provide appropriate follow-up. If these ten "commandments" are followed, the consultation is more likely to be effective and satisfactory for all the participants.

Humans↗
PubMed1982

Intravenous naloxone in acute respiratory failure.

A 58-year-old man presented with acute on chronic respiratory failure. In the acute stage of his illness an infusion of the opiate antagonist naloxone caused an improvement in oxygen saturation as measured by ear oximetry from 74% to 85%, while a saline infusion resulted in a return of oxygen saturation to the original value. When he had recovered from the acute episode the same dose of naloxone had no effect on oxygen saturation. These findings suggest that in acute respiratory failure there may be overproduction of, or increased sensitivity to, endorphins.

Acute Disease↗
PubMed1982

Reversible drug-induced parkinsonism. Clinicopathologic study of two cases.

Parkinsonism developed in two patients who were received neuroleptic drugs. In each case the clinical manifestations remitted completely when the offending drug or drugs were discontinued. Histologic examination in each patient disclosed abnormalities characteristic of idiopathic paralysis agitans (IPA). Levels of homovanillic acid were low in both cases, and dopamine (DA) levels were measurably reduced in the striatum in one case. It is postulated that before administration of neuroleptic drugs, both patients had preclinical IPA, which predisposed them to parkinsonism when challenged with DA antagonists. Our observations suggest that some patients with irreversible drug-induced parkinsonism may suffer from IPA and that the reversibility of clinical features does not exclude the presence of subclinical IPA.

Aged↗
PubMed1982

Failure to demonstrate an effect of in vivo diagnostic ultrasound on sister chromatid exchange frequency in amniotic fluid cells.

Antepartum use of diagnostic ultrasound has markedly reduced radiation exposure of the fetus. Previous investigations have documented the safety of ultrasound, but concern persists regarding its long-term effects. As new methods become available to study possible subtle effects of ultrasound, it is important to reevaluate this technique continually because of its universal use in obstetrics and elsewhere. We report results of in vivo studies of effect of diagnostic ultrasound on the sister chromatid exchange (SCE) frequency in amniotic fluid cells. SCE is a cytogenetic phenomenon believed to be a sensitive indicator of environmental perturbations and chromosome stability. In amniotic fluid cells from six pregnancies without ultrasound exposure and in 34 pregnancies that received varying amount of ultrasound immediately before amniocentesis, there was no difference in SCE frequency in exposed verus nonexposed cells. These data, which appear to confirm again the safety of ultrasound, are reassuring to both patients and clinicians.

Amniotic Fluid↗
PubMed1982

Reduced presynaptic dopamine receptor density after chronic antidepressant treatment in rats.

Chronic administration of desipramine and nomifensine to rats reduced the number of presynaptic dopamine receptors as labeled by 3H-dopamine in rat striatal tissues, with no change in receptor affinity. This change can only be brought about by continuous daily treatment with antidepressants for a duration of at least 21 days or longer. All antidepressants did not displace 3H-spiperone or 3H-dopamine at low concentrations in vitro, suggesting that the agents may not act on the dopamine receptors directly. A possible interaction between neurotransmitters in the central nervous system for the overall therapeutic effect of antidepressant drugs was proposed.

Animals↗
PubMed1981

Metabolism of 2-hexadecynoate and inhibition of fatty acid elongation.

Dietary methyl-2-hexadecynoate appeared to inhibit fatty acid elongation in intact animals (Wood, R., Lee, T., and Gershon, H. (1980) Lipids 15, 141-150). Data from the present in vitro studies indicate that the microsomal elongation system is inhibited preferentially to the mitochondrial system. A series of metabolic acyl-CoA thioester intermediates has been isolated, characterized, and identified from microsomal and mitochondrial incubations with the 2-hexadecynoic acid (16 identical to 1 delta 2). The data support the following conclusions: 1) 16 identical to 1 delta 2 is activated to the CoA ester; 2) 16 identical to 1 delta 2 is acted on by an isomerase to produce a 2,3-allene; 3) either 16 identical to 1 delta 2 or the allene, or both, are hydrated to yield a beta-keto-CoA thioester after rearrangement; 4) the beta-keto ester is reduced to the beta-hydroxyacyl-CoA; 5) dehydration of the beta-hydroxy ester gives rise to trans-delta 2-hexadecenoate which accumulates; and 6) accumulation of the latter results from the inhibition of enoyl-CoA reductase by the 2,3-allene. The occurrence of cis and trans delta 3-hexadecenoates indicates the allene is reduced, after which the delta 3 monoene isomer may be isomerized to the delta 2 monoene by the acetylene isomerase or a different enzyme. Indirect evidence suggests that the fatty acid elongation systems may also be inhibited at another site.

Alkynes↗
PubMed1981

Pharmacological effects of 2-aminotetralins, octahydrobenzo[f]quinolines and clonidine on the isolated guinea pig ileum.

The ability of derivatives of 2-aminotetralins (2AT), cis- or trans-isomers of octahydrobenzo[f]quinolines (BfQ) and clonidine to modulate acetylcholine release was studied using field-stimulated guinea pig ilea (GPI). Antihistaminic and antiacetylcholine activities were also determined using isolated superfused segments of GPI. Hydroxylated 2AT, BfQ and clonidine inhibited field stimulation-induced contractions through alpha-adrenoceptor mechanisms which were antagonized by phentolamine. In contrast, the inhibition produced by nonhydroxylated 2AT was not attenuated by alpha-adrenoceptor antagonism. 2AT, trans-7,8-dihydro-BfQ and cis-8,9-dihydroxy-BfQ inhibited contractions induced by nicotine bitartrate using superfused GPI. Clonidine was inactive as an antinicotinic agent and there was no correlation between a compound's ability to inhibit contractions induced by field stimulation and its antinicotinic activity. Various 2AT derivatives demonstrated weak antimuscarinic and/or antihistaminic activities on superfused ileal segments. These data demonstrate that these agents possess a spectrum of pharmacological activity.

2-Naphthylamine↗
PubMed1981

A specific acetylhydrolase for 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine (a hypotensive and platelet-activating lipid).

1-Alkyl-2-acetyl-sn-glycero-3-phosphocholine, a phospholipid with platelet activating and hypotensive properties, has an extremely labile acetate grouping. The acetate group is obviously important in the expression of the biological properties of this unique derivative of plasmanic acid since once it is hydrolyzed from the parent compound to form the lyso product, all biological activity is lost. Our studies show that the enzyme responsible for the hydrolysis of the acetate moiety, 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine: acetylhydrolase, occurs in the cytosolic fraction of a variety of tissues and has a pH optimum of 7.5 to 8.5. Effects of calcium, magnesium, EDTA, dithiothreitol, deoxycholate, and diisopropylfluorophosphate on the enzyme activity and the fact that egg phosphatidylcholine was not inhibitory indicate that acetylhydrolase activity has different properties from those normally associated with the phospholipase A2 that utilizes phospholipids with two long chain acyl groups. The highest specific activity of the acetylhydrolase occurred in kidney; lung and brain were also good sources of the enzyme. The soluble fraction from the kidney cortex had an apparent Km and Vmax of 3.1 microM and 17.8 nmol/min/mg of protein, respectively. Our results indicate that acetylhydrolase plays a significant role in the catabolism of 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine.

Animals↗
PubMed1981

[Study of monocyte function in patients with cervical cancer by using T-lymphocyte monocyte interaction in response to phytohemagglutinin (author's transl)].

Monocytes have been thought to play an important role in the immune surveillance system of cancer patients since monocytes were shown to participate as accessory cells in the induction of T-cell proliferation to PHA by Potter et al. in 1977. We had already reported the depression of monocyte function with the progress of cancer after PHA response of mononuclear cells obtained by centrifugation of Ficoll-Hypaque and lymphocytes obtained by depletion of monocytes ingesting Silica from mononuclear cells was compared in cancer patients. In that study, however, monocyte function was considered not to be indicated truly because responding cells were different at each examination. Therefore, in this study responding cells were graded as T-cells obtained from healthy volunteers and monocytes were added to the T-cells. Monocyte function in this study was as follows: PHA response to T-cells and monocytes over PHA response to T-cells. In this study, monocytes were allogenic to T-cells. At first, the influence of monocytes to allogenic T-cells was studied but it was found to be negligible. The ratio of monocytes and T-cells was 1:1. The concentration of PHA was 20 micrograms/ml. Finally, the monocyte function of patients with cervical cancer was studied. It was increased at the stage of CIS and then gradually decreased. At the advanced stage, it was significantly decreased to comparison with that of healthy volunteers.

Cell Communication↗