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Biomedical subjects

T C Martin

Publications and source records attributed to T C Martin.

At least 19 recordsLinked to original sources
PubMed1996

Protein markers in cerebrospinal fluid from BSE-affected cattle.

Two-dimensional gel electrophoresis was used to analyse cerebrospinal fluid (CSF) from 75 suspect cases of bovine spongiform encephalopathy (BSE), 61 of which were confirmed by post mortem brain histopathology, and 38 normal cattle. CSF samples were also examined from cattle killed at periodic intervals through the incubation period following experimental challenge. Consistent changes were recorded in all CSF samples from the confirmed cases of natural BSE and also from cattle showing early signs of experimental disease. The changes consisted of an increased intensity of staining of apolipoprotein E and the presence of two protein spots, as yet unidentified, of molecular weights 35 and 36 kDa, both with a pI of 5.5. These changes were absent in the CSF samples from the normal cattle, from the clinically suspect cattle which were not confirmed as BSE and from the experimentally challenged cattle in the preclinical phase of infection.

Animals↗
PubMed1996

Infection and cellular activation by human T-cell leukemia viruses, types I and II.

Resting peripheral blood mononuclear cells (PBMC) or purified T-cells can be induced to proliferate when cocultured in vitro with fixed HTLV-infected T-cells. This process of HTLV-dependent cellular activation and induction of proliferation has been considered distinctive because of an apparent independence from conventional T-cell costimulatory signals. We have examined several HTLV-infected cell lines and found that proliferation was readily induced in resting PBMC by T-cells that were productively-infected with HTLV. However, equivalent HTLV-productive infection in a B-cell line failed to induce proliferation in PBMC, suggesting that HTLV-dependent induction of proliferation in PBMC was, at least in part, dependent upon a T-cell-specific signal. Furthermore, the induction of proliferation in PBMC populations was found to overlap with, and actually require, transfer and establishment of HTLV infection within the T-cell compartment of the PBMC population. These findings suggest that virus-induced activation of target cells may be directly associated with transfer and spread of HTLV infection.

Antigens, CD↗
PubMed1992

Primary surgical closure of large ventricular septal defects in small infants.

Herein, a policy of primary surgical closure of large ventricular septal defects in infants is reviewed. Forty-eight infants met criteria for inclusion in the study, and were divided into two groups based on weight: group 1 infants weighted 4 kg or less (n = 23), and group 2 infants weighed more than 4 kg (n = 25). Both groups had similar variation in ventricular septal defect location (paramembranous versus muscular) and number (single versus multiple), as well as incidence of major associated extracardiac diseases. No early deaths occurred in group 1, compared with 1 infant (4%) in group 2. Major complications occurred similarly in both groups (9% versus 12%). There were two late deaths in group 1 (9%) and none in group 2. No surviving patients have required a second ventricular septal defect operation, and the majority no longer receive anticongestive therapies. These results indicate that primary surgical closure of large ventricular septal defects, even multiple muscular defects, can be performed in very small infants with no difference in mortality or serious complication rates compared with larger infants. Protracted medical efforts to achieve larger size before primary repair and palliative pulmonary artery banding are not necessary.

Body Weight↗
PubMed1992

Complete repair of total anomalous pulmonary venous connection in infancy.

From 1983 to 1990, 20 infants underwent complete repair of isolated total anomalous pulmonary venous connection. Twelve were male; ages ranged from 1 day to 240 days (mean 32 days). The abnormal anatomic connection was supracardiac in nine, cardiac in four, mixed in five, and infradiaphragmatic in two. In seven patients the pulmonary venous drainage was obstructed. Corrective operations were performed 2.4 days after admission; after medical stabilization, seven patients underwent emergency operations, including extracorporeal membrane oxygenation in one. All operations were performed with the use of circulatory arrest (mean 33 minutes) and cardiopulmonary bypass (mean 54 minutes). There was one hospital death, which occurred in a premature infant (1.5 kg) who had supracardiac drainage. No preoperative risk factors correlated with a poor surgical outcome. Pulmonary hypertensive episodes were expectantly managed after the operation with 100% oxygen, sedation, and hyperventilation. Postoperative arrhythmias occurred predominantly in patients with intracardiac drainage. All survivors (mean follow-up of 42 months) are in sinus rhythm, receiving no medications, and are growing and developing normally. Surgical correction of total anomalous pulmonary venous connection in infancy can be performed at low risk with good results after aggressive preoperative stabilization and postoperative management.

Cardiopulmonary Bypass↗
PubMed1990

Combined deficiency of beta-galactosidase and neuraminidase: natural history of the disease in the first 18 years of an American patient with late infantile onset form.

We describe the clinical findings over the first 18 years of a patient with a novel phenotype for galactosialidosis, the storage disease produced by the combined deficiency of beta-galactosidase and neuraminidase. Clinical findings in the first few months included somewhat unusual appearance and hepatosplenomegaly. Dysostosis multiplex was evident by age 2 1/2 years. Mitral and aortic valvular disease appeared over the next few years and cardiac disease has become the most important clinical problem. Foam cells were present in the bone marrow, and vacuolated lymphocytes were present in the peripheral blood smear. The patient had no neurological symptoms, cherry red spots, or intellectual deterioration during the first 18 years. Evidence presented elsewhere indicates that the basic defect in this late infantile form of galactosialidosis (as is thought to be true for the other forms of galactosialidosis) is a reduced amount of the 32 kDa phosphoglycoprotein which associates with beta-galactosidase and alpha-neuraminidase in lysosomes.

Aortic Valve Insufficiency↗
PubMed1989

Evaluation of pulmonary arterial morphology in cyanotic congenital heart disease by magnetic resonance imaging.

Before and after surgical therapy, the anatomy of the pulmonary arteries in cyanotic congenital heart disease is often distorted. Pulmonary arterial anatomy was evaluated by magnetic resonance imaging (MRI) and angiography in 20 patients, ages 3 months to 20 years, with cyanotic heart disease associated with decreased pulmonary blood flow. Excellent correlation between MRI and angiographic estimates of pulmonary artery diameter was obtained (main pulmonary artery, r = 0.96; right pulmonary artery, r = 0.93; left pulmonary artery, r = 0.96). A similar excellent correlation (kappa = 0.83) was found in the assessment of the presence and severity of proximal pulmonary arterial stenoses. However, stenoses in the peripheral pulmonary arteries visualized with angiography were missed with MRI. MRI and angiography showed complete agreement in determining the patency of 11 surgical shunts. MRI did not demonstrate all of the systemic collateral vessels present with angiography, and the distal connections of collaterals were not detected with MRI. MRI is comparable to angiography in the evaluation of central pulmonary arterial anatomy over a wide range of ages. These findings suggest an important role for noninvasive MRI in the serial evaluation of pulmonary artery morphology in patients with cyanotic congenital heart disease before and after surgical repair.

Adolescent↗
PubMed1989

Intraoperative evaluation of atrioventricular septal defect repair by color flow mapping echocardiography.

Despite improving survival rates after repair of atrioventricular septal defect, many patients require reoperation because of postoperative heart failure. We used intraoperative color flow mapping echocardiography to assess the results of surgical repair of atrioventricular septal defect in 19 consecutive patients and compared those findings with results three to five days and 3 to 11 months after repair. There was close correlation between intraoperative and postoperative color flow mapping echocardiography in estimating the presence and severity of left atrioventricular valve regurgitation. All patients survived surgical repair, but in 4 (21%), postoperative congestive heart failure due to left atrioventricular valve regurgitation developed. The need for reoperation was significantly correlated with the severity of left atrioventricular valve regurgitation (r = 0.68) as estimated by intraoperative echocardiography and preoperative aberrancies in the atrioventricular valve (r = 0.68). Age, weight, additional congenital heart disease, preoperative pulmonary vascular resistance, preoperative atrioventricular valve regurgitation, and postoperative mean pulmonary arterial or left atrial pressure were not significantly correlated with the need for reoperation. Intraoperative color flow mapping echocardiography can accurately predict the development of early postoperative heart failure and subsequent reoperation after surgical repair of atrioventricular septal defect.

Child↗
PubMed1989

Management and follow-up of arterial thrombosis in the neonatal period.

The management and follow-up of 12 patients with major aortic thrombus formation occurring in the neonatal period between 1982 and 1987 are reported. Umbilical arterial catheters were inserted in 8 of the 12 patients before thrombus formation. Two patients had congenital thrombi. Hypertension, oliguria, hematuria, and elevated blood creatinine concentration were found at the time of diagnosis of the thrombus; nine of the patients had a patent ductus arteriosus. Supportive care was instituted in seven patients who were hemodynamically stable. Five of the patients had congestive heart failure, shock, or both, and were treated with surgical thrombectomy. Thrombolytic therapy was not used in either group. The five surgically treated patients and six of seven medically treated patients survived. Ultrasound examination suggested resolution of the thrombus in all survivors in 6 to 30 days. Sequelae from thrombus formation were present in all patients at the time of discharge and included hypertension in 9 of the 11 survivors and decreased renal function in six of them. Follow-up at 1 to 3 years revealed normal blood pressure, good growth, and good renal function in 10 of the survivors.

Anticoagulants↗
PubMed1989

Recent trends in marital disruption.

The post-1980 decline in the crude divorce rate must be interpreted in the context of the long-term trend and in terms of what we know about composition effects on crude measures-particularly given shifts in age at marriage and the age composition effects of the baby boom. Data from the June 1985 Current Population Survey permit more detailed, exposure-specific measurements as well as the use of separation as the event terminating marriage. Estimates from these data suggest a decline followed by a recovery. Taking into account well-known levels of underreporting, we find that recent rates imply that about two-thirds of all first marriages are likely to end in separation or divorce. We examine the persistence of major differences in marital stability and evaluate the comparative stability of first and second marriages.

Age Factors↗
PubMed1988

Dilated cardiomyopathy in infants and children.

The outcome of medical treatment of dilated cardiomyopathy in infants and children was reviewed to develop a predictive index for selection of patients likely to benefit from cardiac transplantation. The clinical findings, laboratory investigations, treatment and outcome of 20 patients (Group 1) less than 2 years of age at presentation and 12 patients (Group 2) greater than 2 years of age at onset were compared. Of 20 Group 1 patients, 5 (25%) died. Available autopsies (four patients) showed endocardial fibroelastosis. Of 15 survivors, 10 showed improvement in cardiac status and 5 remained unchanged. Ninety-three percent of survivors had dilated cardiomyopathy consistent with endocardial fibroelastosis by angiocardiography. All 12 Group 2 patients died. In addition to age at presentation and poor outcome, Group 2 differed from Group 1 in having a higher incidence of other family members with cardiomyopathy, more significant rhythm disturbances at presentation and a more rapid course to death. Risk factors of poor outcome in both groups included persistent cardiomegaly and the development of significant arrhythmias by Holter electrocardiographic monitoring. Cardiac transplantation is recommended for children with dilated cardiomyopathy presenting after age 2 years who survive 1 month. Those patients less than 2 years old at presentation whose condition has not improved after 1 year and who have persistent cardiomegaly or complex ventricular arrhythmias may also benefit from transplantation.

Actuarial Analysis↗
PubMed1983

Spontaneous closure of secundum atrial septal defect in infants and young children.

The records of 264 pediatric patients with uncomplicated ostium secundum atrial septal defect (ASD) were reviewed. Eighty-seven patients were younger than age 4 years at the time of cardiac catheterization. Subnormal weight gain, frequent pneumonia, cyanosis or tachypnea were present in 26 patients (30%). Of the 36 infants at catheterization, 17 (48%) had the previously described symptoms, including 12 (33%) who had congestive heart failure. Eight of the 36 infants were found to have closed their defect at a subsequent catheterization. Six of 18 patients who underwent cardiac catheterization between 1 and 2 years of age also had spontaneously closed their ASD at subsequent study. Statistical analysis of hemodynamic data revealed no difference (except a smaller shunt size) between ASDs that closed and those that did not in patients who were less than 4 years at initial catheterization. Analysis of hemodynamic data revealed no statistical differences between groups of patients with an ASD who were younger than and those older than 4 years at time of diagnostic study. Patients with ASDs that closed were significantly different from patients with atrial level shunting thought to be secondary to a valve-incompetent foramen ovale with respect to age at initial study (11 versus 2 months, p less than 0.001), mean left atrial pressure (7.7 versus 12.3 mm Hg, p less than 0.02) and difference between mean right and left atrial pressures (1.0 versus 4.2 mm Hg, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Angiocardiography↗
PubMed1983

Changes in ventricular refractoriness after an extrastimulus: effects of prematurity, cycle length and procainamide.

This study was performed to determine the ability of extrastimuli to change ventricular refractoriness. We prospectively evaluated the effects of stimulus prematurity and paced cycle length (PCL) in 30 patients and the effect of procainamide in 8 patients on changes in the ventricular effective refractory period (ERP) after a right ventricular extrastimulus (S2). An S2 was introduced at preselected coupling intervals at a PCL (S1-S1) of 600 and 400 ms. At each S1-S2 interval, a second extrastimulus (S3) was introduced in 5-ms decrements and the ERP of S2 measured. The decrease in the ERP after an S2 was directly related to prematurity and most of the shortening occurred over a narrow range of S1-S2 intervals. At a PCL of 600 ms, the ERP of S2 at S1-S2 intervals less than or equal to 400 ms was significantly shorter than the ERP of S1 (maximal shortening 23%). At a PCL of 400 ms, the ERP of S2 at S1-S2 intervals less than or equal to 350 ms was significantly shorter than the ERP of S1 (maximal shortening 25%). The ERP of S2 at the shortest S1-S2 interval was greater with a PCL of 600 ms than with 400 ms (200 +/- 31 versus 180 +/- 26 ms, p less than 0.001). However, the total shortening in ERP (ERPS1 - ERPS2 at shortest S1-S2 interval) was similar at both PCLs (55 +/- 14 versus 59 +/- 13 ms). Procainamide significantly prolonged the ERP of S2 at each S1-S2 interval.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1983

Fasciola hepatica: effects of diamfenetide free amine on in vitro physiology, biochemistry, and morphology.

Short-term (1-3 hr) incubations in vitro of immature and adult Fasciola hepatica with 10(-4) to 10(-5) M free amine of diamfenetide (DPT-FA) demonstrated a time/dose-dependent, irreversible paralysis that involved an increase in muscular tension and decrease in contraction amplitude. The following events occurred preceding or concomitant with the paralysis: influx of Na+, decrease in surface membrane potential, increase in wet weight, swellings on the ventral surface, and inhibition of 3-O-methyl glucose transport. These events were all consistent with a disturbance in surface membrane functions. The effects of DPT-FA were more severe in immature flukes (3-5 weeks postinfection) than adults which agrees with observed in vivo efficacy.

3-O-Methylglucose↗
PubMed1983

Estimation of melatonin in bovine plasma: patterns in Jersey heifers treated with cloprostenol at two times of day.

The estimation of melatonin in bovine plasma by radioimmunoassay is described and some aspects of specificity are discussed. Mean values for individual heifers ranged from 0.025 to 0.25 nmol/l during the day and were significantly (P less than 0.01) raised in each animal to mean values of 0.19 to 1.41 nmol/l at night. The hormonal changes after cloprostenol injections were not affected by the time of day at which the heifers were treated.

Animals↗