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Biomedical subjects

R A Forse

Publications and source records attributed to R A Forse.

At least 91 records · Page 5Linked to original sources
PubMed1989

Effects of rapid glucose infusion on in vivo and in vitro free fatty acid re-esterification by adipose tissue of fasted obese subjects.

Adipose tissue lipolysis and fatty acid re-esterification were examined simultaneously in vivo and in vitro in fasted human subjects receiving a constant intravenous infusion of 14C palmitate and large intravenous infusions of glucose and insulin. Under these circumstances, the plasma [FFA] declines rapidly while the specific activity of plasma FFA increases. Plasma [glycerol] remains stable or declines slowly. These in vivo changes in FFA and glycerol metabolism appear to reflect increased adipose tissue re-esterification of FFA, without an attendant decline in rate of lipolysis. However, in vitro rates of re-esterification in gluteal adipose tissue did not change sufficiently to account for the in vivo phenomena. We conclude that: (1) re-esterification in adipose tissue is an important mechanism for the decline in [FFA] induced by glucose infusion in fasted man, but in vitro studies of adipose tissue from a gluteal site do not explain the changes in plasma free fatty acid levels; (2) our data suggest that control of the net mixture of metabolic fuels leaving the adipocyte may be under the influence of pericellular blood flow in addition to ambient humoral factors or intrinsic characteristics of the adipocyte.

Adult↗
PubMed1989

Antibiotic prophylaxis for surgery in morbidly obese patients.

The rate of wound infections in morbidly obese patients who underwent gastroplasty surgery at our institution was 16.5% compared with a rate of 2.5% in normal-weight patients who underwent clean-contaminated surgery. Both groups received 1 gm of cefazolin intramuscularly before surgery was performed. We hypothesized that this regimen of prophylaxis did not provide adequate tissue levels in the morbidly obese. Morbidly obese patients who were undergoing gastroplasty were randomly selected to receive 1 gm cefazolin in the buttock fat, buttock muscle, or by intravenous injection. A fourth group of morbidly obese patients received 2 gm of cefazolin intravenously. Normal-weight patients who were undergoing upper abdominal surgery received 1 gm of cefazolin intravenously. At incision and closure, both blood and tissue levels of cefazolin were significantly (p less than 0.001) lower for all morbidly obese patients who received 1 gm cefazolin when compared with the blood and tissue levels of the drug found in normal-weight patients. The cefazolin levels obtained were below the minimal inhibitory concentrations of greater than 2 micrograms/ml for gram-positive cocci and of greater than 4 micrograms/ml for gram-negative rods. Only when the morbidly obese patient received 2 gm cefazolin were both the serum and adipose tissue levels adequate. For a 4-month period, all morbidly obese patients received 2 gm cefazolin prophylaxis, and the wound infection rate dropped to 5.6% compared with the previous rate of 16.5% (p less than 0.03). We conclude that antibiotic prophylaxis must be specially tailored to the needs of these obese patients.

Adipose Tissue↗
PubMed1988

Revision of failed horizontal gastroplasty by vertical banded gastroplasty.

Eighteen patients who had undergone horizontal gastroplasty experienced postoperative weight gain due to technical failure (large orifice in 10 patients, staple-line disruption in 7 and a large pouch in 1). A vertical banded gastroplasty was used to correct the problem, with a resulting operative morbidity of 38.9%. This included perforation with peritonitis (five patients) and complete outlet obstruction (two patients). These complications appear to result from poor blood supply to the area of the anastomosis necessary in this conversion. This study indicates that it is not safe to use vertical banded gastroplasty for the failed horizontal gastroplasty.

Adult↗
PubMed1987

Adrenergic control of adipocyte lipolysis in trauma and sepsis.

Adipocyte lipolysis and its adrenergic control were studied in vitro from normal patients and those with trauma and sepsis. The adrenergic receptors were studied in terms of their responsiveness, a measure of the postreceptor mechanism, and their sensitivity, a measure of the receptor number or affinity. With early trauma, beta-adrenergic responsiveness and receptor number were significantly decreased. This is desensitization of the beta-receptors with down regulation and indicates increased in vivo lipolysis in early injury. After 4 days these changes had returned to normal. Early sepsis resulted in a significant increase in beta- and alpha-receptor responsiveness with beta-upregulation. This indicated hypersensitivity of the adipocyte adrenergic receptors and suggests the presence of an in vivo block of the adrenergic receptors in early sepsis. This would decrease adipocyte lipolysis. After 4 days there was a decrease in beta-receptor responsiveness in the patients with sepsis, indicating that the adrenergic receptor block was no longer present and adipocyte adrenergic stimulated lipolysis was increased.

Adipose Tissue↗
PubMed1986

The metabolic and ventilatory response to the infusion of stress hormones.

Sepsis and trauma result in increases in epinephrine, glucagon, and cortisol secretion as well as alterations in respiratory pattern that is characterized by increased minute ventilation, decreased tidal volume, and increased frequency. Six male subjects were infused for 5.5 hours with cortisol, epinephrine, and glucagon in amounts designed to simulate plasma levels seen in patients following trauma. During the initial 20 minutes of the hormone infusion, minute ventilation (VE), oxygen consumption (VO2), and carbon dioxide production (VCO2) increased above preinfusion values. VCO2 increased more than VO2 resulting in an increase in respiratory quotient (RQ) from 0.93 to 1.14. The increase in VE was due to increased tidal volume and not frequency (f). After 4.5 hours, the VE, VO2, and VCO2 were still above preinfusion levels but the RQ had decreased to 0.98 because of a decrease in VCO2. Frequency had increased from 19 +/- 4.8 breaths/min preinfusion to 22 +/- 4.7 after 4.5 hours. After 4.5 hours, VT was still above preinfusion levels while pH and PaCO2 had decreased below them. The latter was associated with an increase in serum lactate. At no time was a decrease in tidal volume observed. Therefore, the infusion of these hormones does not simulate all the alterations observed during trauma and sepsis.

Adult↗
PubMed1986

Ventilatory effects of the stress hormones in normal man.

The ventilatory responses to catecholamine infusions have been well studied. Increases in plasma levels of cortisol and glucagon during stress may exert a synergistic effect with epinephrine. We examined the effect of epinephrine and a combined hormone infusion in four normal postabsorptive subjects. On three separate occasions each subject was assigned randomly to receive a 5.5-h infusion of saline (control), epinephrine (1.2 micrograms/m2 . min), or epinephrine plus cortisol (5 mg/m2 . min) plus glucagon (3 mg/kg . min). Oxygen consumption (VO2), CO2 production, minute ventilation (VE), tidal volume (VT), frequency (f), inspiratory flow, and inspiratory time during room-air breathing and inhalation of 2% and 4% CO2 were measured before infusion and during the last 2 h of infusion, using a noninvasive canopy system. VO2 increased significantly (p less than .05) from the control condition during both combined and epinephrine infusions (23% and 11%, respectively). The increase in VE was related linearly to the increase in VO2, and was primarily due to an increase in VT; however, there was a small rise in f. The VE-PaCO2 regression during CO2 inhalation was shifted leftward to an equal degree during both infusions. These data indicate that cortisol and glucagon augment the calorigenic action of epinephrine; ventilatory effects are augmented in relation to the changes in VO2.

Adult↗
PubMed1986

The effect of interleukin-1 and interleukin-2 on the adrenergic control of hormone-sensitive lipase in the human adipocyte.

The effect of interleukin-1 and interleukin-2 on lipolysis and the adrenergic control of lipolysis was studied. Biopsy specimens of human adipose tissue were incubated in media containing 3H-palmitate and 14C-glucose, and the ratio of these isotopes was used to determine adipocyte lipolysis. Isoproterenol, clonidine, and theophylline were used in the media to stimulate the beta 1- and alpha 2-receptors and the subreceptor mechanism, respectively. Interleukin-1 had no effect on basal lipolysis, and at maximal receptor stimulation, it had no effect on the adrenergic receptor control of lipolysis. Interleukin-2 had no effect on basal lipolysis or on the beta-adrenergic receptor. Interleukin-2 significantly (p less than 0.02) decreased the alpha 2-inhibition of lipolysis by 68%. The effect of interleukin-2 on the alpha-receptor was demonstrated to be a significant 45% decrease (p less than 0.03) in the receptor responsiveness (a measure of the postreceptor mechanism) with no alteration in receptor sensitivity (a measure of receptor number). This data suggest that interleukin-2 stimulates lipolysis by decreasing the alpha 2-adrenergic inhibition of hormone-sensitive lipase.

Adipose Tissue↗
PubMed1985

Possible teratogenic effects of artificial insemination by donor.

Three trisomic offspring conceived by artificial insemination by donor (AID) were observed in a population in which a total of about 400 babies were so conceived. To test whether this excess represented a random fluctuation or a real effect of the AID procedure we surveyed, by questionnaire, a group of women who had born children conceived by AID. A significantly higher number of trisomic offspring were found than expected in a population with the observed age distribution. Further data are needed to test the validity of this observation.

Abortion, Spontaneous↗
PubMed1985

Reliability of the total lymphocyte count as a parameter of nutrition.

To evaluate the total lymphocyte count as a means of nutritional assessment, body composition studies (a proven method of nutritional assessment) and total lymphocyte determinations were performed simultaneously in 153 patients. The total lymphocyte count correlated poorly with both the body cell mass and the nutritional state measured by the Nae to Ke ratio. For diagnosing malnutrition, the total lymphocyte count had a false-positive rate of 34% and a false-negative rate of 50%. In a group of 78 patients who received total parenteral nutrition for 2 weeks, the total lymphocyte count did not accurately reflect the nutritional changes. Due to its poor sensitivity and specificity, the total lymphocyte count is of no value as a measure of the nutritional state.

Body Composition↗
PubMed1983

The response to TPN. A form of nutritional assessment.

Malnutrition in surgical patients is associated with an increased incidence of postoperative mortality and morbidity. Preoperative nutritional support has been shown to be efficacious in reducing the incidence of these complications, although the postoperative complication rate in these patients continues to be greater than in their wellnourished counterparts. This study attempts to determine whether the postoperative course can be either influenced by or predicted from the preoperative response to nutritional support. Thirty-two patients with nutritional depletion who received an average of 1 week of total parenteral nutrition prior to a major abdominal operation were studied. These patients were followed for postoperative complications. Of the 16 patients who exhibited the characteristic response to early nutritional support, diuresis of the expanded extracellular fluid compartment with a resultant loss of weight (127.9 +/- 5.7 to 124.6 +/- 5.8 (SEM) lbs, p less than .001) and rise in serum albumin (3.21 +/- 0.14 to 3.46 +/- 0.15 gms%, p less than 0.001), only one developed a complication in the postoperative period. The other 16 patients did not exhibit this response. They retained additional fluid, gained weight (119.3 +/- 8.1 to 121.3 +/- 8.2 lbs, p less than .025), and showed a decrease in serum albumin levels (3.14 +/- 0.14 to 3.00 +/- 0.14%), p less than 0.01). Eight of these patients developed a total of 15 postoperative complications (p less than 0.01). This study demonstrates that the response to preoperative TPN is an important factor in assessing operative risk and morbidity. The need to individualize preoperative nutritional support and the timing of surgical intervention is clearly demonstrated.

Aged↗
PubMed1981

Reliability of skin testing as a measure of nutritional state.

The reliability of skin testing to assess the nutritional state was evaluated in 257 patients who received total parenteral nutrition (TPN). The nutritional state was assessed by determining body composition, by multiple-isotope dilution. Immunocompetence was simultaneously evaluated by skin testing with five recall antigens. These measurements were carried out before and at two-week intervals during TPN. A statistically significant relationship existed between the response to skin testing and the nutritional state. A body composition consistent with malnutrition was present in the anergic patients, while body composition was normal in the patients who reacted normally to skin testing. However, a considerable overlap existed as 43% of the reactive patients were malnourished, and 21% of the anergic patients were normally nourished. Thirty-seven (43%) of the 86 anergic patients converted and became reactive during TPN, and their body composition improved significantly. The remaining 49 anergic patients (57%) did not convert, and their body composition did not change despite similar nutritional support. The principal difference between the two groups of anergic patients was the nature of the therapy administered. In the anergic patients who converted, therapy was aggressive and appropriate, and clinical improvement occurred in 23 (62.2%) of the patients, with a mortality of 5.4%. In the 49 patients who remained anergic, therapy was often inappropriate or unsuccessful, with clinical improvement in only three (6.1%) of the patients and a mortality of 42.8%. The data demonstrated a significant relationship between the response to skin testing and the nutritional state. However, because of the wide overlap, skin testing does not accurately assess a person's nutritional state. The persistence of the anergic state is indicative of a lack of response to therapy.

Female↗
PubMed1981

On genetic screening of donors for artificial insemination.

Reliable information on the frequency of birth defects in children conceived by artificial insemination is lacking and should be collected. Genetic screening of donors for artificial insemination is recommended, and guidelines are proposed. These consider the kinds of disorder in the presumptive donor, or his relatives, that would preclude his use as a donor, and the steps to be taken with relatives, that would preclude his use as a donor, and the steps to be taken with respect to genetic counseling if a defective baby is born following the procedure.

Abortion, Spontaneous↗
PubMed1980

Protein and calorie requirements with total parenteral nutrition.

Body composition measurements, performed by multiple isotope dilution, were used to determine the protein and caloric requirements of patients receiving total parenteral nutrition (TPN). In addition the relative efficacy of lipid as opposed to carbohydrate calories were evaluated. Patients requiring TPN were randomly allocated to receive one of the following TPN solutions: a) 2.5% amino acid with 25% dextrose b) 5% amino acid with 25% dextrose c) 2.5% amino acid with 12.5% dextrose and a 5% lipid emulsion. The efficacy of each solution was evaluated by determining body composition at the onset,and at two week intervals during the course of TPN. In 204 patients who received TPN for 4447 days, 533 body composition studies were performed to evaluate 308 periods of TPN. In the normally nourished patient, as defined by the pre-TPN body composition, the body composition remained unchanged and normal with the three solutions. In the presence of preexisting malnutrition, two weeks of TPN resulted in a significant increase in body weight, arising primarily from an increase in the body cell mass. To evaluate the relative importance of the various factors responsible for the increase in the body cell mass, a multiple linear regression analysis was performed. The mean daily change in the body cell mass was correlated with the carbohydrate, protein and lipid calories infused and with the nutritional state. The resulting regression equation, which was statistically significant, indicated that the rate at which a depleted body cell mass was restored was related to the lipid and carbohydrate calories infused and to the nutritional state of the patient. Carbohydrate calories were more efficient than lipid calories. However increasing the amino acid concentration from 2.5 to 5% had no effect on the rate at which the body cell mass increased. The repletion rate was also directly related to the severity of malnutrition. Thus the correction of a malnourished individual with TPN is dependent on the severity of malnutrition, the type and amount of calories infused but is not affected by increasing the amino acid concentration from 2.5 to 5%.

Body Composition↗
PubMed1980

Jejunal diverticulosis.

Jejunal diverticulosis is an uncommon condition, but it is often associated with a number of symptoms including postprandial abdominal pain, distension, flatulence, borborygmus, nausea, vomiting, diarrhea and constipation and with complications such as vomiting blood or coffee grounds material, melena and shock. The authors report such a condition in a 71-year-old man. Resection is the treatment of choice for relieving symptoms, and for preventing or treating complications.

Aged↗