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Biomedical subjects

C Marks

Publications and source records attributed to C Marks.

At least 55 records · Page 3Linked to original sources
PubMed1988

Circulating concentrations of porcine ileal peptide but not hexosaminidase are elevated following 1 hr of mesenteric ischemia.

Porcine Ileal Peptide (PIP) is located in the mucosa of the small bowel. We hypothesized that PIP may be useful as a marker for early intestinal ischemia or other acute processes of the mucosa. To test this hypothesis we developed a model of acute reversible intestinal ischemia in the pig. Following isolation of a 100-cm segment of ileum on a vascular pedicle baseline, serum and tissue samples were obtained. The vessels were then occluded for 60 min and the segment was reperfused. Serial serum samples were taken and analyzed for PIP and hexosaminidase (HEX). HEX enzyme activity in serum is known to be elevated in animals having intestinal necrosis. The Student t test for paired data was used. In preliminary studies we found that circulating HEX activity became elevated following 3 to 4 hr of vessel occlusion followed by reperfusion. In the current experiments, following 1 hr of ischemia, PIP rose significantly in the peripheral circulation, being 153.8 +/- 76.8, 909.0 +/- 150.4, and 898.3 +/- 128.1 ng/ml (P less than 0.001) at 0, 60, and 360 min after reperfusion of the segment. HEX on the other hand did not change significantly throughout the experiment, having been 766.0 +/- 28.1, 752.0 +/- 71.3, and 780.1 +/- 53.7 nM/liter (ns) at 0, 60, and 360 min following reperfusion of the segment. Histology demonstrated some clubbing, shortening and fracturing of villi with thinning of the tips of the villi in many cases. Immunospecific staining for PIP was present along the intact borders of the villi.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Oxygen uptake and energy output during walking of obese male and female adolescents.

Oxygen uptake and steady-rate energy output of 7 obese male and 13 obese female adolescents (greater than 178% ideal body weight) walking at four different speeds (1.167, 1.5667, 1.7833, and 2.125 m/s) were studied. Body composition was measured by hydrostatic weighing, and steady-rate energy output by open circuit spirometry. Energy output was expressed as kJ/min (kcal/min) and indexed to body mass and fat-free mass. A 2-by-4 ANOVA (sex by speed) revealed significant differences in the energy output between the speed conditions. There was no significant difference between the sexes. A nonlinear increase in calorie output with increasing speed indicated a decreasing efficiency with increasing speed of walking. Possible reasons include biomechanical factors such as increased upper-body forward lean needed to maintain balance at faster speeds of movement, increased energy output due to increased inertia, extra energy output needed to accelerate the limbs and torso, and increased body fat.

Adolescent↗
PubMed1988

Basal metabolism of obese adolescents: inconsistent diet and exercise effects.

Effects of 20 wk of diet-plus-behavior (DB) therapy or exercise-plus-diet-plus-behavior (EDB) therapy on changes in basal energy expenditure (BEE) were studied in 36 obese male and female adolescents. BEE was assessed by open-circuit spirometry and body composition by hydrostatic weighing. Dietary restriction was based on the dietary-exchange program. Behavioral treatment included record-keeping, stimulus-control, and reinforcement techniques. EDB therapy included 50 min/d, 3 d/wk of aerobics. A time-by-group (2 X 3) repeated-measures ANOVA was used to analyze pre-to-postintervention differences between groups (DB, EDB, and control). Results revealed small but statistically significant (p less than 0.05) differences in body composition between the two experimental groups and control subjects. There were no differences in body composition between the DB and EDB groups, although all control subjects gained body mass (p less than 0.05). There was no group-by-time interaction for BEE. Moderate correlations of r = less than or equal to 0.61 were obtained between change in BEE and change in body composition for the subjects in the experimental groups.

Adolescent↗
PubMed1988

Chylothorax causing reversible T-cell depletion.

Study of a patient with traumatic chylothorax after blunt chest trauma defines the changes in cellular immunocompetence during nonoperative management and emphasizes the importance of defining these parameters in addition to documenting the effects of metabolic deterioration.

Adult↗
PubMed1988

Thymoma and aregenerative anemia.

Among 32 patients with thymoma treated at the Louisiana State University Medical Center, there was one patient with aregenerative anemia attributable to thymoma (an incidence of 3.3%). Despite successful surgical removal of the thymoma, there was only slight improvement of the hematologic status three years after thymectomy. The result in this patient approximates the general experience, with hematologic remission being likely in less than 20% of cases. Experience casts doubt on whether treatment with adrenocortical steroids, mediastinal irradiation, or splenectomy provides significant beneficial effects.

Anemia, Aplastic↗
PubMed1988

A study of the potential pharmacokinetic interaction of lisinopril and digoxin in normal volunteers.

1. The pharmacokinetics of single oral doses of 20 mg lisinopril and 0.25 mg digoxin, given alone and together, have been studied in 12 normal young male volunteers. 2. Peak serum conc of lisinopril occurred at 6 to 8 h and were slightly higher during combined treatment. Subsequent elimination proceeded moderately rapidly in both cases, concn declining to approx. 25% of peak values in 24 h. The AUC of lisinopril was similarly slightly higher during combined treatment. 3. After lisinopril alone, urinary elimination of unchanged lisinopril was 13% dose in 72 h, and after combined therapy was 17% dose. 4. Although there were no statistically significant differences in lisinopril pharmacokinetics during single or combined treatment, serum and urinary parameters suggest that bioavailability may be enhanced slightly during combined treatment. 5. Plasma concentrations of digoxin were slightly lower and urinary excretion slightly higher during combined treatment, the mean renal clearance being 20% higher.

Adult↗
PubMed1988

Blood pressure in obese adolescents: effect of weight loss.

The BP distribution of a group of 72 obese adolescents was determined both before and after weight loss. Weight loss was produced by a program of caloric restriction and behavior change alone (n = 26) or with a combination of caloric restriction, behavior change, and exercise (n = 25). It was demonstrated that obese adolescents have a BP distribution that is skewed 1 SD to the right of normal (P less than .01), and that with weight loss this distribution was no longer different from that of the general population. It was also shown that a weight loss program that incorporates exercise and caloric restriction produces the most desirable effect on BP reduction (ie, greatest decrease in resting systolic BP and greatest decrease in exercise diastolic and mean BP). Finally, it was demonstrated that obese adolescents have structural changes present in the forearm resistance vessels and that these structural changes are reversed to the greatest extent in the weight loss program that includes exercise.

Adolescent↗
PubMed1987

Outpatient surgery for prolapsed lumbar disc.

A selected series of 14 patients with lumbar disc prolapse causing sciatica have been operated successfully with outpatient (daycase) surgery. Postoperative pain has been much less than expected. This form of surgery has proved very acceptable to patients and to their family doctors.

Ambulatory Surgical Procedures↗
PubMed1986

Biological and technological variability of residual lung volume and the effect on body fat calculations.

Ten subjects were studied to determine within-subject variance (Swi2), and its components, biovariability (Si2) and technological error (Se2) of residual lung volume (RLV). Each subject's RLV was determined 18 times using the oxygen dilution method (O2D) over a 5-day period. Se2 was measured using a 9.0 l spirometer as a simulated subject and estimating its added space by the O2D method for 20 repeat trials. The mean +/- SD of RLV across subjects was 1.408 +/- 0.3143 l. The average Swi2 for the 18 trials was 0.0054 (Swi = +/- 0.0735 l). The variance associated with a trend effect (variance of mean trial scores, Sc2) was 0.00050 (Sc = +/- 0.0224 l). Se2 was found to be 0.00104 (Se = +/- 0.0323 l). Si2 calculated by subtracting Se2 and Sc2 from Swi2, was 0.0039 (Si = +/- 0.0621 l). It was demonstrated that body fat weight calculations can vary because of the within-subject variability in RLV. The calculated reliability of RLV across subjects was r = 0.95. It is concluded that RLV determined by the O2D method is very reliable. Moreover, biological variance accounts for 72% of Swi2 while technological variance and trend effect variance account for 19 and 9% of Swi2 respectively.

Adult↗
PubMed1985

Double-blind, multicenter controlled trial comparing topical dimethyl sulfoxide and normal saline for treatment of hand ulcers in patients with systemic sclerosis.

A prospective, randomized, double-blind trial compared topical therapy with 0.85% normal saline, 2% dimethyl sulfoxide (DMSO), and 70% DMSO for treatment of digital ulcers in 84 patients with systemic sclerosis. There were no statistically significant differences among the 3 treatment groups in the improvement in the total number of open ulcers, total surface area of open ulcers, average surface area per open ulcer, number of infected ulcers, number of inflamed ulcers, or patient pain assessment. While some patients improved during the study, improvement could not be attributed to a specific treatment. Over one-quarter of the patients treated with 70% DMSO were withdrawn for significant skin toxicity.

Administration, Topical↗
PubMed1985

Hepatic tumors and oral contraceptives: surgical management.

The clinical and pathological features of 14 patients with benign liver tumors are reviewed. There were two males and 12 females in this series of cases. All but one of the females had been on contraceptive steroid therapy for an average of 7.8 years. Abdominal pain was the presenting complaint in 75% of cases, a palpable abdominal mass was present in 22%, while 12.5% of the patients presented with acute hemorrhagic shock due to rupture of a liver cell adenoma. Liver cell adenomas (LCA) were found in 87.5% of the cases and a diagnosis of focal nodular hyperplasia (FNA) was made at histologic examination of the resected tumors in 12.5% of cases. Surgical resection of the liver tumors was performed successfully in 89% of the cases. Hepatic lobectomy was accomplished in four patients, hepatic segmentectomy was possible in three cases, while local wedge resection or focal excision were indicated on seven occasions. There was no operative mortality in this series, but one patient required reoperation for drainage of a complicating subphrenic abscess.

Adult↗
PubMed1985

Basal metabolism of obese adolescents: age, gender and body composition effects.

Body composition (percent fat and lean body mass) and basal metabolic rates were determined in 67 obese adolescents ranging in age from 10 to 16 years (30 male, 37 female). Basal oxygen uptake was determined on rising in the morning using open-circuit spirometry with a 10-min collection period. Body composition was determined from body density measurements using the underwater weighing procedure. There were no male-female differences (except for basal VCO2 production, P less than 0.05) for any body composition or metabolic variable. The subjects' (male and female) average weight was 73 kg, height--157 cm, percent fat--40 percent, fat weight--30 kg, lean body mass--92 kg, and kcal/24 h--1535. Correlations between age, body composition and basal energy expenditure were all moderate to low (r less than or equal to 0.78). In contrast to adult data, lean body mass was not highly correlated to basal energy expenditure suggesting that perhaps there is a 'metabolic condition' of the obese adolescent modulated by excess fatness or the instability of the body cell mass. Stepwise multiple linear regression revealed that for the obese male adolescent, body surface area and percent fat, and for the obese female adolescent body surface area and body weight resulted in the best prediction of basal kcal/24 h. The standard errors of prediction were +/- 17.9 percent for the males, and +/- 14.4 percent for the females.

Adolescent↗
PubMed1984

Validity of CO2-rebreathing cardiac output during rest and exercise in young adults.

To validate the CO2-rebreathing method ( Defare 's method) for estimating cardiac output in children and young adults, measurements were compared to thermodilution ( TDCO ) cardiac output in 16 subjects (age 7-19 yr) with congenital heart disease. Data were collected at rest (N = 11) and during 4-min stages of supine bicycle exercise (N = 13). Estimated arterial-venous (-v-a)CO2 content differences related linearly to the measured CO2 content difference (Y = 0. 29X + 2.47, r = 0.65, P less than 0.001). With this (v-a)CO2 difference correction for all patients (N = 16), the correlation between CO2-rebreathing cardiac output and the TDCO was r = 0.87 (SEE = +/- 1.8 l X min-1). The correlation was higher for exercise (r = 0.81) than for rest (r = 0.65). We conclude that the CO2-rebreathing method, with a (v-a)CO2 content difference adjustment, is a simple, noninvasive technique providing estimates of cardiac output in children and young adults with congenital heart disease. Individual estimates should be treated with caution, especially when used for clinical evaluations.

Adolescent↗
PubMed1984

The parasacral approach to the rectum.

The posterior parasacral approach to the rectum is well-suited to several benign conditions and may occasionally be indicated in malignant rectal disorder. The York Mason modification of the Kraske procedure permits preservation of the sphincters and preservation of anal continence. The procedure is recommended as part of a surgeon's repertoire in operations on the rectum.

Adult↗
PubMed1983

Overwhelming postsplenectomy sepsis in childhood.

Three hundred ninety-three splenectomies were performed within the Charity Hospital system during the decade from 1969 through 1979. This number included 56 operations in children under 16 years of age, which formed the basis of this report of the risk of infection in young splenectomized patients and provided guidelines for the role of splenectomy under emergency and elective conditions. Eight episodes of serious infection were documented in four patients. There was only one case of overwhelming postsplenectomy infection which resulted in death, for a mortality rate of 1.8 percent (1 of 56 children) for death due to overwhelming postsplenectomy sepsis. It is emphasized, however, that the development of serious postsplenectomy sepsis in our series resulted in a 25 percent mortality rate. The risk of postsplenectomy sepsis is much greater in those individuals who are immunologically compromised, such as those who undergo staging splenectomy for Hodgkin's disease. If splenectomy is indicated for a hematologic disorder, it is wise to defer operation for as long as possible, especially if the acute episodes are self-limiting or mild. Rather than the promiscuous use of polyvalent serum and antibiotic therapy after splenectomy in children, it is recommended that parents be advised to bring the child to the hospital anytime an illness or fever develops that might require an immediate loading dose of an appropriate antibiotic. The role of subtotal splenectomy or hemisplenectomy merits consideration in staging Hodgkin's disease. Preoperative study of certain immunologic parameters may provide guidelines as to the proportion of individuals who may be vulnerable to overwhelming sepsis after splenectomy.

Adolescent↗
PubMed1983

Extracranial carotid artery injury. Current surgical management.

Fifty patients were treated for extracranial carotid artery trauma during the period from 1954 through 1981. The overall mortality rate was 20 percent. Primary repair was achieved in 38 patients (76 percent) with a mortality of 7.8 percent, and ligation was performed in six patients (12 percent) with a 50 percent mortality. The left carotid system was injured more frequently than the right; hemorrhage from an isolated carotid injury was readily controlled by digital pressure. Associated injuries affected the prognosis adversely. Significant neurologic deficits were present in 12 patients on first admission but the presence of neurologic deficit or coma did not serve as a contraindication to arterial repair and restoration of cerebrovascular continuity. Arteriography was not utilized once the clinical diagnosis of carotid arterial injury was made, but it was utilized when the proximity of the cervical injury provided the only suggestive evidence that vascular damage may have occurred. The presence of significant shock, coma, or neurologic deficit represent adverse prognostic features but do not contraindicate carotid repair. Profuse bleeding from a carotid injury or the presence of severe posthemorrhagic shock require urgent surgery. If control of bleeding is difficult to achieve, then ligation is preferred to suture repair.

Adolescent↗