Biomedical subjects
J Thomas
Publications and source records attributed to J Thomas.
Low birthweight in African Americans: does intergenerational well-being improve outcome?
The primary antecedent of infant mortality is low birthweight. Vital statistics data have shown that women of low socioeconomic status, regardless of race, are at greater risk for delivering low birthweight infants; however, prevailing data show that black women of the same socioeconomic status as white women have a twofold higher risk of giving birth to an infant weighing < 2500 g and a threefold risk of delivering a very low birthweight infant weighing < 1500 g. There is also evidence that intergenerational effects on birth outcome exist. However, virtually all studies of the effect of socioeconomic status on perinatal outcome have been cross-sectional; the effect of sustained intergenerational well-being has not been measured. To address this gap, this study was designed to demonstrate that in an African-American population with sustained high socioeconomic status and equal risk factors, the birthweight distribution and other reproductive outcomes are the same as those for comparable US white populations. Preliminary findings are reported here.
The modified radical mastectomy of Patey: technique and experience.
We report our experience from 193 patients with breast cancer treated by Modified Radical Mastectomy of Patey and describe the technique used, amplified by illustrations. We achieved a low morbidity viz symptomatic lymphoedema five cases, chronic shoulder stiffness one case, skin grafting two cases, and all cases of chest wall pain cleared by four years. Cancer recurred, to date, local in nine cases (4.6%), local and systemic in 17 cases (8.9%) and systemic in 27 cases (13.9%). We compile, for the first time, all references by Patey and Richard Handley to the procedure. We recommend the operation as achieving complete primary clearance with safe and full axillary node removal. Histological state of the nodes allows rational decisions on adjuvant therapy with hormones and chemotherapy.
[Microalbuminuria before and one month after extracorporeal lithotripsy. First results].
Extracorporeal shock wave lithotripsy represents extraordinary progress for the treatment of urinary calculi. The apparent aggressivity of this technique leads to investigating whether it may have an impact on the renal parenchyma, as was suggested by many works, especially with radionuclide explorations. Microalbumin assays before and about one month after lithotripsy show an iatrogenic pathological increase in levels in some cases, especially after long, intensive sessions of treatment, whether the lithotripter used was of the shock-wave or piezoelectric-wave type. When lithotripty was performed with a piezoelectric-wave device, the increase in microalbumin is related to the "cumulative" factor, which is in turn related to the power, frequency (per second) and length of shots. More extensive investigations and, most importantly, investigations over a longer period are necessary to confirm or invalidate the results of this first study, to establish the frequency of cases where this abnormality appears, whether it can last long, and how far it can be predictive of the parenchymal lesions and of their long-term impact.
Effect of depleting CD3+ cells from DR- donor bone marrow to facilitate kidney graft tolerance in recipients given total lymphoid irradiation.
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Prolongation of cardiac xenograft survival by pre- and posttransplant splenectomy is associated with a decrease in anti-donor antibody titers.
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Deoxyspergualin and rabbit antithymocyte globulin markedly prolong discordant pig pancreatic islet xenografts.
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Splenectomy is a potent immunosuppressive modality for cardiac xenografting.
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Reduction in primary nonfunction of pancreas islet transplants with antithymocyte globulin agents, deoxyspergualin, and splenectomy.
These results suggest that DSG and RATG are an especially favored combination in reducing PNF of discordant pig islet xenografts, probably related to the effect of DSG on the macrophage, humoral antibody, or blockade of NK cell activity. More effective immunosuppression such as demonstrated in this study could well be critical in permitting the application on discordant islet xenografts to human clinical diabetes.
Reversal of type II diabetes by pancreas islet transplant in four separate animal models of type II diabetes.
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Vocal characteristics of children with cleft lip/palate and associated velopharyngeal incompetence.
This investigation was designed to evaluate the relationship between aerodynamic measures of velopharyngeal competence and laryngeal function in individuals with repaired cleft palate. Twenty-seven cleft lip and palate or cleft palate individuals, between the ages of 4 and 16 years, were evaluated in an ENT clinic for assessment of vocal function. A commercially available aerodynamic (pressure/flow) system for evaluating velopharyngeal function was used to classify estimated opening of the velopharyngeal port during speech production. Aerodynamic measures of laryngeal function (transglottal pressure and airflow, and laryngeal airway resistance) were also collected. A computerized system for acoustic analyses of voice production was employed to determine vocal characteristics of pitch perturbation (jitter), amplitude perturbation (shimmer) and signal-to-noise ratio (SNR). The results suggested that the cleft speakers showed numerically larger measures of perturbation in the vocal signal, and greater laryngeal airway resistance than their normal controls. Subgroups of cleft palate speakers, based on their vocal dynamics, were proposed. Implications for medical and behavioral management for these subgroups are discussed.
Structure of Leishmania mexicana lipophosphoglycan.
Lipophosphoglycan (LPG) was isolated from the culture supernatant of Leishmania mexicana promastigotes and its structure elucidated by a combination of 1H NMR, fast atom bombardment mass spectrometry, methylation analysis, and chemical and enzymatic modifications. It consists of the repeating phosphorylated oligosaccharides PO4-6Gal beta 1-4Man alpha 1- and PO4-6[Glc beta 1-3]Gal beta 1-4Man alpha 1-, which are linked together in linear chains by phosphodiester linkages. Each chain of repeat units is linked to a phosphosaccharide core with the structure PO4-6Gal alpha 1-6Gal alpha 1-3Galf beta 1- 3[Glc alpha 1-PO4-6]Man alpha 1-3Man alpha 1-4GlcNH2 alpha 1-6 myo-inositol, where the myo-inositol residue forms the head group of a lyso-alkylphosphatidylinositol moiety. The nonreducing terminus of the repeat chains appear to be capped with the neutral oligosaccharides Man alpha 1-2Man, Man alpha 1-2Man alpha 1-2Man, or Man alpha 1-2[Gal beta 1-4]Man. Cellular LPG, isolated from promastigotes, has a very similar structure to the culture supernatant LPG. However, it differs from culture supernatant LPG in the average number of phosphorylated oligosaccharide repeat units (20 versus 28) and in alkyl chain composition. Although culture supernatant LPG contained predominantly C24:0 alkyl chains, cellular LPG contained approximately equal amounts of C24:0 and C26:0 alkyl chains. It is suggested that culture supernatant LPG is passively shed from promastigotes and that it may contribute significantly, but not exclusively, to the "excreted factor" used for serotyping Leishmania spp. Comparison of L. mexicana LPG with the LPGs of Leishmania major and Leishmania donovani indicate that these molecules are highly conserved but that species-specific differences occur in the phosphorylated oligosaccharide repeat branches and in the relative abundance of the neutral cap structures.
Coronary stenting with a balloon-expandable stent after the recanalization of chronic total occlusions.
To diminish the restenosis rate after successful recanalization of chronic total coronary occlusion, we have implanted the Palmaz-Schatz stent in 6 patients. All procedures were successfully done without major complications. The angiographic follow-up at 6 months showed restenosis in one asymptomatic patient who had had 2 stents implanted. Five other patients had no evidence of restenosis.
Initial experience with the disarticulated (one-half) Palmaz-Schatz stent: a technical report.
We developed an alternative method to stent suitable lesions located in anatomical settings considered to be too complex for regular Palmaz-Schatz stent placement. This method consists of using a disarticulated (one-half) Palmaz-Schatz stent. Eight patients underwent stenting utilizing this method. The left anterior descending was stented in five patients, the right coronary artery in one patient, the proximal and mid shaft of a vein graft in one patient, and a protected left main coronary artery in one patient. In all patients the stents were placed in addition to full stents. In four patients, 1 1/2 stents were placed; two patients had 2 1/2 stents; one patient had 3 1/2 stents and the last patient had a total of 5 stents placed (1 full stent and 8 half stents). One patient had 8 disarticulated stents placed. All half stents prepared for delivery were successfully deployed to the pre-designated angiographic site without complication.
Coronary stenting: single institution experience with the initial 100 cases using the Palmaz-Schatz stent.
We studied 100 patients who had coronary implantation of Palmaz-Schatz stents in our institution from November 1989 until March 1991. A total of 126 standard and 6 short stents were implanted. The patients' mean age was 58 +/- 5 years, and 97 were males. The indications were lesions with high risk of restenosis (29 patients), restenosis (27 patients), suboptimal result of angioplasty (24 patients), dissection (16 patients), and recanalized chronic total occlusion (6 patients). In 17 patients a brachial cut-down approach was used. Stents were correctly placed in 98 patients. Stent related complications occurred in 9 patients: major ischemic complications in 7 patients (acute myocardial infarction in 2 patients, emergency bypass surgery in 3 patients and emergency angioplasty in 2 patients); in 3 of these patients there was a subacute closure of the stent and in 2 patients there were delivery problems. Vascular complications at the site of arterial puncture occurred in 3 patients (some patients had more than one complication). A learning curve was observed. There was a decrease in the complication rate with the higher number of patients treated: 28% for the first 50 patients and 6% for the last 50 patients. Clinical follow-up was available in all patients. Of the 92 patients eligible for follow-up (7 +/- 2 months), 69 patients were asymptomatic and 23 had recurrence of angina: 19 patients for stent restenosis and 4 patients for coronary artery disease progression. Follow-up angiogram was done in 79/92 (86%) patients: 21 had restenosis (27%).(ABSTRACT TRUNCATED AT 250 WORDS)
dup(12)(q13----qter) in two t(14;18)-negative follicular B-non-Hodgkin's lymphomas.
Two t(14;18)-negative follicular B-non-Hodgkin's lymphomas with the same chromosomal abnormality, dup(12)(q13----qter), are presented. The absence of a BCL2 gene rearrangement was confirmed by molecular studies in both cases. Instead, duplication of a 12q segment was found. Further evidence for the presence of the dup(12)(q13----qter) was found using fluorescence in situ hybridization. dup(12q) may be equivalent to the trisomy 12 originally described in B-chronic lymphocytic leukemia. This chromosome anomaly has also been reported in B-non-Hodgkin's lymphomas, usually in association with other chromosome anomalies and a more aggressive tumor phenotype. Occurrence of dup(12q) in two histologically similar cases of follicular small cleaved-cell lymphoma without a typical t(14;18), suggests that this karyotypic change may play a critical role in some cases of follicle center-cell lymphomas.
Influence of D-glucose-induced water absorption on rat jejunal uptake of two passively absorbed drugs.
The intestinal absorption of D-glucose is coupled to transepithelial sodium transport and this process generates intestinal water absorption. In situ jejunal perfusions were performed in rats to determine the extent of water transport as a function of perfusion flow rate, perfusate osmolality, and D-glucose concentration. Jejunal perfusions of iso-osmolar D-glucose, at flow rates and concentrations representative of the fed state, increased the dimensionless membrane permeabilities of the analgesic acetaminophen from 0.6 to 1.4, and that of the corticosteroid prednisolone from 1.6 to 2.2. This increase is less important for the more hydrophobic prednisolone since its baseline permeability (1.6) is indicative of complete uptake from solution, while the lower baseline permeability (0.6) of the more hydrophilic acetaminophen represents incomplete membrane uptake. The results suggest that nutrient-induced water transport can enhance jejunal uptake of small hydrophilic solutes. This phenomenon may contribute to variability in the absorption of drugs in this physicochemical class during the fed state.
Psychiatric diagnostic profiles in hospitalized adolescent and adult Navajo Indians.
Diagnostic profiles of 400 adolescent and 1159 adult Navajo Indians consecutively admitted to a psychiatric unit between 1980 and 1989 are presented in this paper. The major discharge diagnoses for adolescents were as follows: adjustment reaction, mixed, and depression, not otherwise specified (NOS), with females accounting for two-thirds of either diagnosis; schizophrenia, with males accounting for 68% of all diagnoses, and personality disorder, NOS, with no gender differences. The four major discharge diagnoses for adults were schizophrenia and depression, NOS, in which there were no gender differences; alcohol withdrawal, syndrome, in which males accounted for 76% of those discharged; and adjustment reaction, mixed, in which females constituted 60% of those discharged. Over the 10-year period, there was a decrease in adult and an increase in adolescent admissions. During the last 2 years (1988 and 1989) adolescents accounted for almost 30% of all admissions compared with 14% during the first 2 years (1981 and 1982).