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Biomedical subjects

M B Heyman

Publications and source records attributed to M B Heyman.

At least 37 records · Page 2Linked to original sources
PubMed1997

Pathological changes in yearly protocol liver biopsy specimens from healthy pediatric liver recipients.

Many centers perform biopsies on transplanted livers annually to assess allograft function because serum biochemical tests do not always correlate with histological findings. Although criteria exist for diagnosing acute cellular rejection, no similar criteria exist to describe the histopathological changes observed in the "normal" liver of an immunosuppressed but healthy child. The purpose of this study was to define the histopathological changes in the allografted livers of healthy children who have undergone transplantation and to evaluate them during long-term follow-up. One hundred fifty-eight yearly protocol liver biopsy specimens of 54 children who received transplants between January 1988 and March 1996 and at least 1 year of follow-up were reviewed, and the biopsy findings were correlated with those of serum tests of liver function performed concomitantly. Thirty-three biopsy specimens were excluded because serum transaminase levels were abnormal, the biopsy specimen was abnormal and diagnostic for a specific lesion, or follow-up showed progression of a specific disease process. In addition, time zero biopsy specimens from 21 of the 54 children were available for comparison. In the protocol biopsy specimens, portal and/or parenchymal mononuclear inflammatory infiltrates were frequent findings (48% and 25%, respectively). Other less common features were mild fibrosis (8%) and focal pericholangitis (6%). Findings in both protocol and time zero biopsy specimens included minimal to mild bile ductular proliferation (15% and 9.5%, respectively) and rare hepatocyte necrosis (1.6% and 5%). No yearly protocol biopsy specimens resulted in any patient benefit. Transplanted livers in immunosuppressed children who are clinically healthy and have normal transaminase levels commonly show histological changes consisting of scattered, mild to moderate, portal and/or parenchymal mononuclear infiltrates that are clinically insignificant. Yearly protocol biopsies in healthy pediatric recipients have been abandoned by the investigators after 3 years of follow-up.

Biopsy↗
PubMed1997

Ringed esophagus (feline esophagus) in childhood.

Feline esophagus is a term describing a specific radiological and endoscopic appearance of the esophagus that is attributed to chronic esophagitis. To date only one report has described this appearance in childhood. We present a histologically documented case of this entity including follow-up studies after therapy for esophagitis.

Adolescent↗
PubMed1997

Transjugular intrahepatic portosystemic shunts (TIPS) in children.

The transjugular intrahepatic portosystemic shunt procedure is an accepted treatment for adults with complications of portal hypertension. We performed a retrospective review of all pediatric TIPS placements performed at the University of California, San Francisco between 1990 and 1996. Twelve procedures were attempted in nine children, with a mean age (+/- SD) of 9.4 +/- 3.9 years (range, 5 to 15 years) and a mean weight of 31 +/- 18 kg (range, 16 to 70 kg). The indications for TIPS placement were portal hypertension complicated by chronic variceal hemorrhage not controlled with sclerotherapy (n = 7) and hypersplenism with thrombocytopenia (n = 2). TIPS placement was successfully completed initially in seven of nine (78%) patients. Unfavorable vascular anatomy was the cause of failure in two cases. The seven patients who underwent successful TIPS placement were followed up for an average of 136 days (range, 1 to 800 days); two still have patent shunts, three underwent liver transplantation, one had a splenorenal shunt after stenosis, and one died of underlying liver disease. Variceal bleeding was controlled in four of five patients who successfully underwent TIPS placement. Shunt occlusion occurred in four patients; patency was restored by transjugular shunt revision in three, and a splenorenal shunt was performed in one.

Adolescent↗
PubMed1996

Effects of age on energy expenditure and substrate oxidation during experimental underfeeding in healthy men.

Relatively little is known about the influence of age on energy regulation during energy imbalance. We compared the effects of underfeeding on changes in energy expenditure, substrate oxidation, and body energy loss between young men (age 22.0 +/- 0.9 [SEM] years) and older men (age 66.0 +/- 1.8) who were leading unrestricted lives. Changes in total energy expenditure (TEE), resting energy expenditure (REE), the thermic effect of feeding (TEF), respiratory quotient, and body energy loss were determined in response to undereating by 3.17 +/- 0.16 Megajoule (MJ)/day for 21 days in 19 healthy subjects consuming a typical diet. No significant effects of age were observed in changes in TEE, REE, TEF, or body energy loss in response to underfeeding. Thus, older men do not appear to have any impairment of energy conservation during negative energy balance compared to young men. This normal pattern of energy conservation during undereating together with the previously demonstrated reduction in energy dissipation during overeating can be predicted to promote body fat deposition in older men during the cycles of positive and negative energy balance that occur during normal life. This finding may help to explain the increased body fat mass in older individuals.

Adult↗
PubMed1995

Donor selection limits use of living-related liver transplantation.

The purpose of this investigation was to assess the applicability of living-related liver transplantation in an established regional transplant program by determining the frequency of acceptable living donors from an unselected population of pediatric transplant candidates and identify specific factors limiting application of this technique. During the period May 1992 to May 1994, all children accepted as transplant candidates at the University of California-San Francisco were evaluated for potential living-related liver transplantation. Indications for transplantation and patient demographics represented the spectrum anticipated at a regional center. Donor evaluation was performed using a three-phase evaluation process we have previously reported. Retrospective analysis identified 75 potential donors for 38 pediatric candidates (age range, 17 days to 14.5 years; mean, 5.1 years). Twenty-three percent of potential donors declined evaluation. Of the 75 potential donors, only 10 (13%) were found to be acceptable for donation. The leading causes for donor declination were significant medical history (23%), ABO blood group incompatibility (23%), and psychosocial history (20%). Of the 38 recipient candidates, 9 (23%) were offered living-donor transplantation. Five patients have received living-donor transplantation, and 4 patients await the procedure when medical indications exist. Seventy-seven percent of recipient candidates received or are awaiting cadaveric transplantation. These results suggest that current donor criteria markedly limit the application of living-related liver transplantation.

Adolescent↗
PubMed1995

Influence of age on energy requirements.

The effects of aging on energy requirements and energy expenditure were investigated in 35 healthy young men (mean +/- SE age, 22.7 +/- 0.6 y) and elderly men (68.0 +/- 1.5 y). Over a 10-d metabolic balance study, measurements were made of metabolizable energy intake for weight maintenance, total energy expenditure, resting energy expenditure, and thermic effect of feeding. Values for both metabolizable energy intake and total energy expenditure were significantly higher than the current recommended dietary allowance for energy in both age groups (P < 0.01). Total energy expenditures were 14.48 +/- 0.65 and 11.26 +/- 5.40 MJ/d in young and elderly men, respectively. The difference in total energy expenditure between the groups was accounted for by a significant decrease in all the major components of expenditure. These results suggest that the current recommended dietary allowances for energy may underestimate the usual energy needs of healthy adult men.

Adult↗
PubMed1994

Management of constipation and encopresis in infants and children.

Chronic functional constipation is common in childhood. Basic understanding of the defecation process is essential to formulate a rational diagnostic and therapeutic approach to pediatric patients with chronic constipation, with or without encopresis. Primary care physicians can perform a major preventive function by anticipatory guidance and early dietary intervention. Most patients referred to pediatric gastroenterologists can be effectively treated as outpatients with use of an approach consisting of colonic evacuation, stool softeners, dietary manipulations, bowel training, and behavioral management. Avoidance of painful (laxatives) and invasive (suppositories, enemas) modalities is an important part of successful management. Further evaluation, including manometric tests, are reserved for patients with a history or physical findings suggesting an underlying disorder predisposing the patient to difficulty with defecation. Biofeedback therapy is likely destined to play a role in the subgroup who respond poorly to traditional therapeutic methods.

Barium Sulfate↗
PubMed1993

Multicenter trial of d-alpha-tocopheryl polyethylene glycol 1000 succinate for treatment of vitamin E deficiency in children with chronic cholestasis.

BACKGROUND: Malabsorption and deficiency of vitamin E causing neurological degeneration are common consequences of chronic childhood cholestatic liver disease. The objective of this study was to determine the long-term efficacy and safety of d-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) in correcting vitamin E deficiency in children with chronic cholestasis who were unresponsive to other forms of oral vitamin E. METHODS: Sixty vitamin E-deficient children with chronic cholestasis unresponsive to 70-212 IU.kg-1.day-1 of oral vitamin E were entered into a trial at eight centers in the United States. After initial evaluation, treatment was started with 25 IU.kg-1.day-1 of TPGS. Vitamin E status, neurological function quantitated by a specific scoring system, and clinical and biochemical parameters were monitored during therapy. RESULTS: All children responded to TPGS with normalization of vitamin E status. Neurological function, which had deteriorated before entry in the trial, improved in 25 patients, stabilized in 27, and worsened in only 2 after a mean of 2.5 years of therapy. No adverse effects were observed. CONCLUSIONS: TPGS (20-25 IU.kg-1.day-1) appears to be a safe and effective form of vitamin E for reversing or preventing vitamin E deficiency during chronic childhood cholestasis.

Adolescent↗
PubMed1993

Energy expenditure, aging and body composition.

We investigated the importance of adaptive variations in energy expenditure in the regulation of energy balance in young and elderly men of normal body weight leading unrestricted lives. Changes were measured in total and resting energy expenditure and body composition in response to overeating by approximately 4.2 MJ/d or undereating by 3.3 MJ/d for 21 d in 39 young and elderly men consuming a typical diet. In the young men, an average of 85-90% of the excess energy intake during overeating was deposited. During underfeeding, mobilization of body energy compensated for an average of 65% of the energy deficit in these subjects. The resting metabolic rate, averaged for fasting and fed states, increased during overfeeding (+0.63 +/- 0.20 MJ/d, P < 0.01) and decreased during underfeeding (-0.42 +/- 0.12 MJ/d), but at least some of these changes were due to the obligatory expenditure associated with nutrient assimilation. There was no significant change in energy expenditure for physical activity or thermoregulation from overfeeding or underfeeding. Preliminary results indicate that aging had no effect on responses to overfeeding or underfeeding. These findings suggest that adaptive variations in energy expenditure are not the major determinant of energy regulation in young adults of normal body weight and that, instead, energy balance is maintained on a day-to-day basis through the control of nutrient intakes.

Adult↗
PubMed1993

Chronic recurrent esophageal strictures treated with balloon dilation in children with autosomal recessive epidermolysis bullosa dystrophica.

Two children (8- and 17-yr old) with autosomal recessive epidermolysis bullosa dystrophica and chronic esophageal strictures were treated with repeated balloon dilations. General anesthesia was by face mask adapted specifically for this procedure, with careful attention to avoid skin and mucus membrane damage. A balloon dilator positioned fluoroscopically over an angiographic guidewire was gently inflated until narrowings resolved. Dilations have been performed every 1-11 [4.3 +/- 3.2 (mean +/- SD)] months in the younger patient over the last 4.3 yr, and every 8-20 (14.5 +/- 5.9) months in the older patient over the last 4.8 yr, without serious complications. Both patients were able to swallow normal foods following dilations. Repeated balloon dilations of esophageal strictures in patients with epidermolysis bullosa dystrophica can be done safely. Further studies are indicated to determine its effectiveness and appropriateness as an alternative to colonic interposition.

Adolescent↗
PubMed1992

Underfeeding and body weight regulation in normal-weight young men.

The mechanisms of energy regulation invoked by moderate dietary restriction were investigated in seven healthy young men of normal body weight leading unrestricted lives. Following a baseline period of weight maintenance, subjects were underfed by 806 +/- 162 (mean +/- SE) kcal/day for 21 days. Changes in total energy expenditure (TEE) and resting energy expenditure (REE) and subsequent voluntary nutrient intakes were measured. The REE, averaged for fasting and fed states, decreased during underfeeding by 100 +/- 29 kcal/day (P less than 0.01). TEE decreased nonsignificantly by 296 +/- 170 kcal/day, equivalent to an average of 37% of the decrease in energy intake. Body energy stores were estimated to decrease by 510 +/- 172 kcal/day (P less than 0.03), thus compensating for 63% of the dietary energy deficit on average. Voluntary energy intake following dietary restriction increased above the initial amount required for body weight maintenance, was proportional to the weight loss during underfeeding (P less than 0.03), and was associated with a rapid regain of weight lost during underfeeding. These results indicate that energy balance is regulated by adaptive variations in both energy intake and energy expenditure in normal-weight young men leading unrestricted lives but do not support the hypothesis that energy-wasting mechanisms contribute substantially to body energy regulation.

Adult↗
PubMed1992

What are the dietary energy needs of elderly adults?

The energy requirements of healthy elderly men were investigated by measuring total energy expenditure (TEE), body composition and resting energy expenditure (REE), using 2H2(18)O techniques and indirect calorimetry during ten days when a weight maintaining diet was consumed. Values for TEE/REE (1.75 +/- 0.05, s.e.) were significantly higher than the recommended dietary allowances (RDAs) for energy in this age group, as were previously reported values for TEE/REE in a group of young men in the same experimental protocol. There was a significant negative association between TEE/REE (a physical activity indicator) and body fat mass. Combining data from the elderly men in this study and the young men studied previously, age and TEE/REE together accounted for 73% of the variation in body fat mass between individuals. These results lend additional weight to the suggestion that the current RDAs for energy may significantly under-estimate usual energy requirements. They also indicate that the low levels of energy expenditure suggested by the RDAs may favour unnecessarily high levels of body fat mass and that increased levels of energy expenditure are desirable.

Adipose Tissue↗
PubMed1992

Acute hemorrhagic gastritis in the newborn infant.

We report three cases of hemorrhagic gastritis in term infants that led to massive bleeding of life--threatening proportions in the first 24 hours of life. In all three cases, bleeding was controlled by conservative therapeutic management. Management of this unusual entity in the newborn infant is discussed.

Acute Disease↗
PubMed1991

Dietary energy requirements of young adult men, determined by using the doubly labeled water method.

We examined the hypothesis that current recommendations on dietary energy requirements may underestimate the total energy needs of young adult men, by measuring total energy expenditure (TEE) and resting energy expenditure (REE) in 14 weight-maintaining healthy subjects leading unrestricted lives. TEE and body composition were measured by using 2H(2)18O, and REE was measured by using indirect calorimetry. All subjects had sedentary full-time occupations and participated in strenuous leisure activities for 34 +/- 6 (SE) min/d. TEE and REE were 14.61 +/- 0.76 and 7.39 +/- 0.26 MJ/d, respectively, and 202 +/- 2 and 122 +/- 2 kJ.kg-1.d-1. There were significant relationships between TEE and both body fat-free mass (r = 0.732, P less than 0.005) and measured REE (r = 0.568, P less than 0.05). Measured TEE:REE values were significantly higher than the recommended energy requirement (1.98 +/- 0.09, compared with 1.55 or 1.67, P less than 0.005). These results are consistent with the suggestion that the current recommended energy intake for young adult men may underestimate total energy needs.

Adult↗
PubMed1991

Objective verification of dietary intake by measurement of urine osmolality.

A new method for assessing the accuracy of dietary nutrient intakes in metabolic studies is described. The theoretical basis of the method is the comparison of measurements of the urine osmole excretion rate (OER, the product of urine osmolality and urine weight) with values for OER predicted from dietary nitrogen, sodium, and potassium. The method was tested in 34 healthy male and female volunteers aged 18-78 y who made complete 24-h urine collections and consumed a diet over 6 d in metabolic-balance studies involving either overfeeding, weight maintenance, or weight loss. The coefficients of variation for equations relating measured OER to dietary nitrogen, sodium, and potassium intakes ranged from 14.1% for 1-d measurements to 6.94% for 6-d means. These results indicate that it should be possible to use measurements of the urine OER to identify dietary noncompliance in metabolic studies.

Adolescent↗
PubMed1991

No-enema therapy for idiopathic constipation and encopresis.

Idiopathic constipation and encopresis of childhood are thought to occur when children volitionally withhold stool. Withholding may be prompted by social pressures or by episodes of painful defecation. Repetitive withholding may result in colonic dilatation and colorectal dysfunction. Therapy involves removal of impacted stool, stool softening, and behavioral therapy. The use of enemas in this therapy is widespread but may be counterproductive. A retrospective review of patients treated without enemas revealed 45 patients whose course could be followed for six months. Ninety-eight percent of these had successful initial cleanouts without enemas; 94% had continued success at six months. These results, comparable with other treatment programs, demonstrate that therapy without enemas is a reasonable alternative in the treatment of childhood constipation and encopresis.

Child↗