Search

Objectives: In this study, we evaluated the relationship between household food security status and developmental risk in young children, after controlling for potential confounding variables., Methods: The Children's Sentinel Nutritional Assessment Program interviewed (in English, Spanish, or Somali) 2010 caregivers from low-income households with children 4 to 36 months of age, at 5 pediatric clinic/emergency department sites (in Arkansas, Massachusetts, Maryland, Minnesota, and Pennsylvania). Interviews included demographic questions, the US Food Security Scale, and the Parents' Evaluations of Developmental Status. The target child from each household was weighed, and weight-for-age z score was calculated., Results: Overall, 21% of the children lived in food-insecure households and 14% were developmentally "at risk" in the Parents' Evaluations of Developmental Status assessment. In logistic analyses controlling for interview site, child variables (gender, age, low birth weight, weight-for-age z score, and history of previous hospitalizations), and caregiver variables (age, US birth, education, employment, and depressive symptoms), caregivers in food-insecure households were two thirds more likely than caregivers in food-secure households to report that their children were at developmental risk., Conclusions: Controlling for established correlates of child development, 4- to 36-month-old children from low-income households with food insecurity are more likely than those from low-income households with food security to be at developmental risk. Public policies that ameliorate household food insecurity also may improve early child development and later school readiness.

The US Food Security Scale (USFSS) measures household and child food insecurity (CFI) separately. Our goal was to determine whether CFI increases risks posed by household food insecurity (HFI) to child health and whether the Food Stamp Program (FSP) modifies these effects. From 1998 to 2004, 17,158 caregivers of children ages 36 mo were interviewed in six urban medical centers. Interviews included demographics, the USFSS, child health status, and hospitalization history. Ten percent reported HFI, 12% HFI and CFI (H&CFI). Compared with food-secure children, those with HFI had significantly greater adjusted odds of fair/poor health and being hospitalized since birth, and those with H&CFI had even greater adverse effects. Participation in the FSP modified the effects of FI on child health status and hospitalizations, reducing, but not eliminating, them. Children in FSP-participating households that were HFI had lower adjusted odds of fair/poor health [1.37 (95% CI, 1.06-1.77)] than children in similar non-FSP households [1.61 (95% CI, 1.31-1.98)]. Children in FSP-participating households that were H&CFI also had lower adjusted odds of fair/poor health [1.72 (95% CI, 1.34-2.21)] than in similar non-FSP households [2.14 (95% CI, 1.81-2.54)]. HFI is positively associated with fair/poor health and hospitalizations in young children. With H&CFI, odds of fair/poor health and hospitalizations are even greater. Participation in FSP reduces, but does not eliminate, effects of FI on fair/poor health.

Standard total parenteral nutrition (TPN), with or without fat, in amounts approximating the ad libitum intake of normal rats is highly lethal for rats following 70% hepatectomy. Because of significant metabolic changes including alterations of branched chain amino acids (BCAA), arginine (ARG), and glutamine (GLN) associated with serious injury, sepsis, and liver dysfunction, we hypothesized that (1) increasing concentrations of BCAA and ARG in TPN and (2) including glutamine in the TPN may diminish the lethality. Male Sprague-Dawley rats with 70% hepatectomy and jugular vein catheterization were divided into groups. Two sets of experiments were conducted. In Experiment 1, the effects of varying concentrations of BCAA and ARG in the TPN infusate, singly and together, were assessed: Group 1, Standard TPN (19% BCAA, 4.8 g ARG/L); Group II, High BCAA TPN (35% BCAA, 4.8 g ARG/L); Group III, High ARG TPN (19% BCAA, 9.6 g ARG/L); Group IV, High ARG, High BCAA TPN (35% BCAA, 9.6 g ARG/L; Group V, chow and tap water ad libitum. In experiment 2, the effect of 2% GLN in TPN was evaluated: Group A, Standard TPN and Group B, 2% GLN TPN. All infusates were isocaloric (216 Kcal/Kg/d) and isonitrogenous (1.94 g N/Kg/d) delivered at half concentration on postoperative day 1, 3/4 concentration on postoperative day 2, and at full concentration thereafter. Experiment 1: Thirty-three to 36% of rats in Groups I (Standard TPN) (4/11), II (High BCAA TPN) (4/11) and III (High ARG TPN) (4/12) died within 6 days. In sharp contrast, none died in Groups IV (High BCAA, High ARG TPN) and V (rat chow and tap water) (P < 0.05 in each comparison). Among rats in the 4 TPN groups surviving 7 days, there were no significant differences in body weight change (minus 3-4%), spleen or lung weight, extent of liver regeneration (61-66%). Serum total protein and albumin were significantly higher in Group V (chow-fed) (similar to values in normal rats) than in Groups I-IV, P < 0.05 in each case. Serum total bilirubin was significantly higher in Group I than in normals and in Groups II, III, and V. Serum lactate dehydrogenase levels were similar in normals and all 5 groups. Serum aspartate amino transferase level was higher in Group I than in normals but not significantly different from those groups II-V; the latter were similar to normals. Experiment 2: Thirty percent of rats in Groups A (Standard TPN) (3/10) and B (GLN TPN) (3/10) died within 6 days. Among rats surviving for 7 days, body weight change (minus 3-5%), liver regeneration (67-70%), and liver tests were similar in both groups. TPN modified to contain high concentrations of both BCAA and ARG (but not of either alone) prevented the high frequency of lethality induced by standard TPN in rats with 70% hepatectomy. No such salutary effect was shown by modifying the TPN to contain 2% GLN. The striking benefit observed when TPN containing high BCAA and high ARG was infused may be due to the high BCAA leading toward normalization of serum amino acid levels, reducing proteolysis, increasing protein synthesis, and accelerating early liver regeneration, combined with the high ARG likely reducing serum ammonia and leading to increased host defense, and perhaps, thereby, preventing bacterial translocation and bacteremia.

Background: Captopril, an angiotensin-converting enzyme inhibitor, used for treating hypertension and heart failure, inhibits angiogenesis in the corneas of rats in response to basic fibroblast growth factor, slows the growth of experimental tumors in rats, and leads to the regression of Kaposi's sarcoma. Because angiogenesis is key to wound healing, we hypothesized that captopril would impair wound healing. We hypothesized also that because local application at operation of Staphylococcus aureus peptidoglycan (SaPG) increases angiogenesis and accelerates wound healing in rats, SaPG would prevent or ameliorate the postulated captopril-impaired wound healing., Materials and Methods: In each experiment, rats were divided randomly into two groups: one drinking tap water, and the other, tap water containing 0.5 mg captopril/ml. All ate chow and drank ad libitum, pre-operatively (4-12 days) and postoperatively (7 days). In experiments 1 and 2, bilateral paravertebral 5.5-cm skin incisions were made aseptically (intraperitoneal sodium pentobarbital), and closed with interrupted No. 35 stainless-steel sutures. On one side, the wound was immediately inoculated with 157 microliter pyrogen-free isotonic saline and on the other side the wound was inoculated with 157 microliter saline containing 4.7 mg SaPG (860 microgram SaPG/cm incision). In the third experiment, polyvinyl alcohol (PVA) sponges (16-17 mg dry wt each) containing either 50 microliter saline or 0.5 mg SaPG in 50 microliter saline were implanted subcutaneously, two on each side, via 1-cm incisions closed with a single suture. In the fourth experiment, 5.5-cm bilateral skin incisions and subcutaneous implantation of PVA sponges were done as described but all sites were instilled with saline only. All rats were euthanized (CO(2) asphyxia) 7 days postoperatively., Results: Wound breaking strength (WBS) of the saline-treated incisions was significantly higher (P < 0.001) in captopril-treated rats than in controls (172 +/- 13 g vs 105 +/- 6 g) in experiment 1 and higher, but not significantly in captopril-treated rats in experiment 2 (153 +/- 8 g vs 114 +/- 6 g) (PNS). SaPG inoculation of the incisions increased WBS significantly in both control and captopril-treated rats: 187 +/- 11 g vs 105 +/- 6 g (P < 0.001) and 283 +/- 16 g vs 172 +/- 13 g (P < 0.001), respectively, in experiment 1, and 217 +/- 13 g vs 114 +/- 6 g (P < 0.0001) (controls) and 266 +/- 17 g vs 153 +/- 8 g (captopril-treated rats) (P < 0.0001) in experiment 2. In experiment 3, subcutaneous PVA saline-inoculated sponge reparative tissue hydroxyproline (OHP) content was similar in control and captopril-treated rats, and SaPG inoculation increased reparative tissue OHP significantly in both groups: 2458 +/- 218 microgram/100 mg dry sponge vs 3869 +/- 230 microgram/100 mg (P < 0.001) (controls) and 2489 +/- 166 microgram/100 mg vs 4176 +/- 418 microgram/100 mg (P < 0.001) (captopril-treated rats). Histologically, angiogenesis and reparative tissue collagen were similar in control and captopril-treated rats, in both saline-inoculated and SaPG-inoculated sponges. In experiment 4 (all incisions and subcutaneous PVA sponges were saline-inoculated), there was no significant difference in WBS between control and captopril-treated rats (107 +/- 6 g vs 96 +/- 5 g, NS). PVA sponge reparative tissue OHP was significantly higher in captopril-treated rats: 3698 +/- 170 microgram/100 mg dry sponge vs 2534 +/- 100 microgram/100 mg (P < 0.0001)., Conclusion: Unexpectedly, in four experiments, captopril did not inhibit WBS or PVA sponge reparative tissue angiogenesis or collagen accumulation; in fact, WBS was increased significantly in one of three experiments, and PVA sponge reparative tissue OHP was increased significantly in one of two experiments. Also, captopril did not interfere with the wound healing-accelerating effect of SaPG., (Copyright 2000 Academic Press.)

Objective: Many organizations make efforts to identify future pediatric leaders, often focusing on chief residents (CRs). Identifying future leaders is an issue of great importance not only to the ultimate success of the organization but also to the profession. Because little is known regarding whether completing a CR predicts future leadership in medicine, we sought to determine if former pediatric CRs when compared with pediatric residents who were not CRs reported more often that they were leaders in their profession., Design/methods: Twenty-four pediatric training programs stratified by resident size (<18, 18-36, and >36) and geography (East, South, Midwest, and West) were selected randomly from the Graduate Medical Education Directory (American Medical Association, Chicago, IL). Program directors were contacted by mail and telephone and asked to provide their housestaff rosters from 1965-1985. The resulting resident sample was surveyed by questionnaire in 1995., Results: Fifteen of 17 program directors (88%) who possessed the requested data provided 1965-1985 rosters yielding a sample of 963 residents. Fifty-five percent of the resident sample (533) responded. Fifty-eight of the respondents had not completed a pediatric residency, leaving a survey sample of 475. Thirty-four percent (163) were CRs. The sample had a mean age of 47, 67% were male and 87% married. Fellowships were completed by 51%. More former CRs compared with non-CRs (75% vs 64%), more former fellows than non-fellows (75% vs 60%) and more males than females (74% vs 55%) reported they were professional leaders. These associations persisted in a logistic regression that controlled for CR status, gender, marital status, and fellowship status as leadership predictors. Former CRs, former fellows, and men were, respectively, 1.8, 2.3, and 2.3 times more likely to report professional leadership., Conclusions: Pediatric residents who were former CRs and/or fellows, and males were more likely to report professional leadership. Although men were more likely to report professional leadership, with more women entering pediatrics the reported gender differences will likely disappear over time.

Background: TGF-beta1 is a pleiotropic cytokine that plays a key role in wound healing and organ fibrosis. We have recently demonstrated that, in part, some fibrogenic actions of TGF-beta1 are mediated via formation of H(2)O(2). We have also demonstrated that TGF-beta1 plays a key role in the accelerated healing response induced by a peptidoglycan derived from some strains of Staphylococcus aureus (SaPG)., Methods: To investigate further the role of H(2)O(2) in healing responses, we implemented and improved a method to measure this reactive oxygen species. Using this method, we quantified the production of H(2)O(2) by cultured hepatic stellate cells-the main cells involved in type I collagen production in the liver-and by saline- and SaPG-inoculated polyvinyl alcohol sponges that had been surgically subcutaneously implanted in the dorsum of rats., Results: We show that cultured hepatic stellate cells produce significant amounts of H(2)O(2). We show also that H(2)O(2) formation by saline- and SAPG-inoculated sponges is more intense during the early inflammatory phase of the healing response and precedes collagen deposition. Moreover, the production of H(2)O(2) is much higher in SaPG-inoculated sponges than in those inoculated with saline solution., Conclusions: Based on these findings, and on the fact that H(2)O(2) is produced during TGF-beta-induced upregulation of the alpha1(I) procollagen gene, we conclude that H(2)O(2) is one of the mediators of healing responses.

A culturally sensitive 3-month intervention was provided to 18 Caribbean Latino men and women with non-insulin-dependent (type 2) diabetes mellitus. Compared to the randomly assigned control group, the intervention group showed statistically significant decreases in total calories, fat calories, percent of calories from fat, saturated fat calories, and percent of calories from saturated fat The intervention group showed increases in calories from carbohydrates and in the percent of calories from fiber.

Diabetes-induced impaired wound healing is characterized by inhibition of the inflammatory response to wounding, macrophage infiltration, angiogenesis, fibroplasia, reparative collagen accumulation, and wound breaking strength. Because all of these processes are accelerated in normal rats by a single local application at operation of Staphylococcus aureus peptidoglycan, we hypothesized that S. aureus peptidoglycan would prevent diabetes-induced impaired wound healing, despite persistent, untreated hyperglycemia, polydipsia, glycosuria, and polyuria. Sprague- Dawley male rats were divided into two groups. One group received an intraperitoneal injection of streptozotocin (65 mg/kg) in citrate solution; the other group received an intraperitoneal injection of an equivalent volume of citrate solution. Seventeen days after the injections, the diabetic and control rats received aseptically two 5.5-cm paravertebral incisions and subcutaneous implantation of six polyvinyl alcohol sponges, three on each side. On one side, each sponge contained 0.5 mg S. aureus peptidoglycan in 50 microliter saline solution, and the incision was inoculated along its length with 4.7 mg S. aureus peptidoglycan in 157 microliter saline solution (860 microgram/S. aureus peptidoglycan/cm incision); on the other side, the same respective volumes of saline were used. During the preoperative and postoperative periods, diabetic rats lost a small amount of weight (2%), were hyperglycemic (363 +/- 10 mg/100 ml blood), polydipsic, glycosuric, and polyuric, whereas the controls gained weight (25%) and were normoglycemic (104 +/- 5 mg/100 ml blood); these differences were significantly different (p <.001 in each case). In controls, S. aureus peptidoglycan inoculation increased wound breaking strength (by a factor of 2.0) and hydroxyproline content (by a factor of 1.4; p <.001 in each case); in diabetics, there were significant decreases in wound breaking strength (by a factor of 1.7) and hydroxyproline content (by a factor of 1.3) of saline solution-inoculated incisions and sponges compared with the wound breaking strength and hydroxyproline content of saline solution-inoculated incisions and sponges in controls (p <.02 and p <.001, respectively). These decreases were completely prevented when the incisions and polyvinyl alcohol sponges had been inoculated at operation with S. aureus peptidoglycan; S. aureus peptidoglycan inoculation in the diabetic rats increased wound breaking strength by a factor of 2.2 and sponge reparative tissue hydroxyproline by a factor of 1.6 (p <.001 in each case). Thus, diabetes-induced impaired wound healing was prevented completely by a single local instillation at operation of S. aureus peptidoglycan, despite persistent, untreated hyperglycemia, polydipsia, polyuria, and glycosuria.

We have previously shown that local application at the time of operation of Staphylococcus aureus, nonviable S. aureus, its cell wall, or S. aureus peptidoglycan accelerates wound healing. We hypothesized that this effect is due to both direct and indirect mechanisms, among which is an increase in the inflammatory response to wounding, resulting in an increase in macrophages, angiogenesis, and fibroblasts. Twenty-seven Sprague-Dawley male rats were anesthetized, and two 7-cm paravertebral skin incisions were made. Four polyvinyl alcohol sponges, two on each side, containing either 100 microliter of isotonic saline or 0.5 mg of nonviable S. aureus or S. aureus peptidoglycan in 100-microliter saline were implanted subcutaneously. Nonviable S. aureus or S. aureus peptidoglycan (860 microgram/cm incision) in 200-microliter saline were inoculated into the incisions at closure. The rats ate a commercial rat chow and drank tap water ad libitum throughout. After days 3 and 7 postwounding, rats were euthanized, and tissues were examined for immunohistochemical features of reparative tissue using ED-1, Factor VIII, and vimentin antibodies, markers for monocyte/macrophages, endothelial cells, and mesenchymal cells (including fibroblasts), respectively. Incisions treated with nonviable S. aureus or S. aureus peptidoglycan showed more macrophages along and deep in the wound tract 7 days postoperatively. Nonviable S. aureus or S. aureus peptidoglycan-treated sponges were surrounded and penetrated by much larger capsules of reparative tissue than saline-treated sponges at both 3 and 7 days. Neutrophil influx was much greater in nonviable S. aureus or S. aureus peptidoglycan-treated sponges, especially in central regions, and there were many more ED-1-stained macrophages in distinct geographic locations, specifically, the more peripheral-cortical areas. Some clustering of macrophages occurred around areas of invasion by reparative tissue into the surrounding subcutaneous fat and within the interstices of the sponges at the interface between reparative tissue and acute inflammatory cells. In contrast, saline-treated sponge reparative tissue had significantly fewer macrophages, much thinner and flimsy reparative tissue, with proportionately fewer macrophages clustering centrally. There were many more mesenchymal cells (notably fibroblasts) and new blood vessels and much more reparative collagen in the nonviable S. aureus or S. aureus peptidoglycan-treated sponges. We conclude that local application of nonviable S. aureus or S. aureus peptidoglycan at wounding induces an increased number and alteration in location of macrophages, increased influx (or proliferation) of mesenchymal cells (notably fibroblasts), and increased angiogenesis and reparative collagen accumulation, as well as increasing the overall acute inflammatory response to wounding.

Although Caribbean Latinos are more likely than non-Hispanic whites to develop diabetes, their health status has been poorly characterized. Information on diabetes management, metabolic control, dietary habits, and diabetes knowledge was gathered from a group of urban Caribbean Latinos with diabetes in order to characterize the nutritional behaviors, diabetes attitudes, health perceptions, and metabolic control of this high risk group. Interviews and medical record reviews were conducted among seventy low-income urban Caribbean Latinos with type 2 diabetes mellitus. Patients attending outpatient clinics were interviewed by bilingual interviewers. Medical records were reviewed to ascertain prevalence of diabetes-related complications, medications, and metabolic parameters. Participants were primarily Spanish-speaking and of Puerto Rican origin. Eighty-one percent were unemployed, and only 27% had completed high school or higher educational levels. Average hemoglobin A1c was 10.6%. Among those with hypertension and hyperlipidemia, many were not receiving treatment. Participants' estimation of their own degree of metabolic control was poor, as was their understanding of desirable blood glucose and weight goals. A second evening meal was common. Diets were higher in fat and sugar content than currently recommended. More effective treatment strategies for both patients and providers are needed to improve glycemic control and cardiovascular risk factors among indigent urban Caribbean Latinos. Essential features of such strategies for patient programs include culturally appropriate dietary counseling and low literacy materials to better communicate glycemic and weight goals and dietary guidelines. Provider education is needed regarding established guidelines and cultural influences on diabetes-related practices.

Polyvinyl alcohol sponges inoculated with Staphylococcus aureus peptidoglycan induce an accelerated wound healing response when implanted subcutaneously in rats. S. aureus peptidoglycan leads to a marked increase (50%) in reparative tissue collagen (as measured by hydroxyproline) by 4 days. However, this effect drops by 7 days and by 14 days; hydroxyproline levels are similar in sponges inoculated with S. aureus peptidoglycan or saline solution. These data suggest a very active early remodeling process in S. aureus peptidoglycan sponge reparative tissue. Consistent with this observation, we had found that steady-state levels of matrix metalloproteinase-13 mRNA were higher and persisted longer in S. aureus peptidoglycan sponge reparative tissue than in controls. We hypothesized that S. aureus peptidoglycan might induce a change in reparative tissue fibroblast phenotype or modify the character of the wound fluid. Fibroblasts obtained from saline solution- and S. aureus peptidoglycan-inoculated sponges 4 days after subcutaneous implantation and cultured in Eagle's minimal essential medium supplemented with 10% fetal calf serum were similar with respect to morphologic features, proliferation, and expression of pro alpha1 (I) and alpha1 (III) collagens and tissue inhibitor of metalloproteinase-1 mRNA by Northern blot analysis. Neither cell type expressed matrix metalloproteinase-13 mRNA. No changes in the above parameters were detected when such fibroblasts were cultured for 24 hours in the presence of 0.5 mg of S. aureus peptidoglycan per 10 ml of medium or with fluid obtained from control sponges cultured for 12 hours with phosphate-buffered saline solution. Wound fluids extracted with Eagle's minimal essential medium by homogenization of saline solution- and S. aureus peptidoglycan-inoculated sponges implanted subcutaneously for 12 hours did not affect the proliferation of the fibroblasts. However, the extracts had a profound effect on the cellular expression of tissue inhibitor of metalloproteinase-1, matrix metalloproteinase-13, and pro alpha1 (I) collagen mRNA. Specifically, expression of matrix metalloproteinase-13 mRNA was induced, expression of pro alpha1 (I) collagen mRNA was reduced by 70%, and expression of tissue inhibitor of metalloproteinase-1 mRNA was increased by 150%. These changes were the same irrespective of whether the wound fluid was obtained from saline solution- or S. aureus peptidoglycan-inoculated sponges. Fluid obtained from S. aureus peptidoglycan-inoculated sponges, which contain a greater inflammatory exudate than saline solution-inoculated sponges do, is enriched in matrix metalloproteinase-13 mRNA-inducing activity. The nature of the factor(s) that induces matrix metalloproteinase-13 mRNA expression is not known. However, preliminary data suggest that the matrix metalloproteinase-13-inducing factor(s) is heterogeneous with regard to size and is temperature sensitive and trypsin resistant.

Cyclophosphamide given systemically to rats leads to impaired wound healing, characterized by decreases in the inflammatory reaction, fibroplasia, neovascularization, reparative collagen accumulation, and wound breaking strength. In contrast, the local application of Staphylococcus aureus peptidoglycan at the time of wounding increases all of these processes in normal rats. Accordingly, we hypothesized that inoculation of S. aureus peptidoglycan into wounds of cyclophosphamide-treated rats would ameliorate the otherwise impaired healing. Dorsal bilateral skin incisions and subcutaneous implantation of polyvinyl alcohol sponges (two on each side) were performed on male Sprague-Dawley rats receiving either saline or cyclophosphamide (24 mg/kg) intraperitoneally at the time of operation, on postoperative days 1, 2, 3, 4 (for rats killed on postoperative day 7), and also on day 8 (for rats killed on postoperative day 14). The incisions on one side were inoculated at the time of closure with 0.2 ml of saline solution, and the incisions on the other side with 6 mg S. aureus peptidoglycan in 0.2 ml saline solution (860 microg/cm incision). The sponges were instilled with 0.1 ml saline solution on the saline solution-instilled incision side or with S. aureus peptidoglycan 0.5 mg/sponge) in 0.1 ml saline solution on the other side. In control rats receiving saline solution intraperitoneally, incisions treated with S. aureus peptidoglycan were significantly stronger than saline solution-treated incisions by a factor of 1.8 at 1 week (p < 0.001); at 2 weeks the increase was small and not significant. Cardiac blood leukocytes and platelets fell markedly (90%) in cyclophosphamide- treated rats, and there was a decrease in wound breaking strength of their saline-treated incisions at both 7 and 14 days compared with saline solution-treated incisions of control rats. S. aureus peptidoglycan treatment of the wounds completely prevented this effect at 7 days, and partially at 14 days. Polyvinyl alcohol sponge reparative tissue hydroxyproline, 7 days after surgery, was decreased in cyclophosphamide-treated rats; this was completely prevented by S. aureus peptidoglycan treatment of the sponges. Histologically, the inflammatory response to the wounding, influx of macrophages and fibroblasts, angiogenesis, and collagen accumulation were all reduced at day 7 and 14 after surgery in the sponge reparative tissue of cyclophosphamide- treated rats; this was prevented by S. aureus peptidoglycan treatment of the sponges. In conclusion, a single local application of S. aureus peptidoglycan ameliorates cyclophosphamide-impaired wound healing.

Objectives: This study assessed current levels of sunbathing and sunscreen use in the United States., Methods: From a general-population telephone survey of aquatic activities among adults in 3042 US households, we examined responses by the 2459 Whites., Results: Most adults (59%) reported sunbathing during the past year, and 25% reported frequent sunbathing. Of the subsample who reported sunbathing during the month before the interview, 47% routinely used sunscreen. Of these individuals, almost half did not use sunscreens with a solar protection factor of 15 or higher., Conclusions: About a quarter of US White adults report frequent sunbathing, and only about a quarter of sunbathers use sunscreens at recommended levels. These results should help focus future sun protection educational efforts.

High mortality occurs in rats with 70% hepatectomy fed intravenous (IV) total parenteral nutrition (TPN; 13.9% glucose, 4.17% amino acids, 1.46% fat, electrolytes, trace minerals, and vitamins providing 216 kcal.kg-1.d-1) but not when the identical nutrients are given at the same rate enterally (gastrostomy). We hypothesized that a difference in bacterial translocation (BT) was a contributing factor to this phenomenon. Forty-five male Sprague-Dawley rats (300-360 g) were divided into five groups and underwent the following: control (no operation), sham (intraperitoneal [IP] pentobarbital anesthesia, central venous and gastrostomy catheters, laparotomy, sham hepatectomy), standard oral feeding (SOF), TPN (IV nutrients), and total enteral nutrition (TEN; gastrostomy). The SOF, TPN, and TEN groups had IP pentobarbital anesthesia, central venous and gastrostomy catheters, and 70% hepatectomy. Postoperatively, control and SOF (both catheters plugged) rats ate a commercial rat chow and drank tap water ad libitum pre- and postoperatively. The sham, TPN, and TEN groups were given the identical infusate composition as above, but the nutrient concentrations were cut in half (110 kcal/kg) and three-quarters (165 kcal/kg) on postoperative days 1 and 2, respectively. At the end of postoperative day 2, all rats were euthanized. BT to mesenteric lymph nodes (MLNs), liver, spleen, and lungs was significantly higher in the TPN rats compared with all other groups, except that BT to the MLNs was similar in the TPN and TEN groups. Bacteremia was found only in the TPN rats. BT in TPN rats with 70% hepatectomy was significantly greater 48 h after operation than in those fed the identical nutrients enterally at the same rate; this correlates with the previously reported significantly greater mortality in rats with 70% hepatectomy receiving TPN.

We have previously reported that local application of viable Staphylococcus aureus dramatically accelerates wound healing, but viable Staphylococcus epidermidis does not. Because the S. aureus effect occurred in the absence of infection and because the cell walls of the two bacterial species differ, we hypothesized that nonviable S. aureus, its cell wall, and its cell wall component(s) would accelerate healing. Nonviable S. aureus was prepared by chemical and physical means, and its cell wall and peptidoglycan was prepared from heat-killed cultures. In a large number of experiments, nonviable S. aureus (independent of the strain's protein A content), its cell wall, and peptidoglycan when instilled locally at the time of wounding each significantly increased the breaking strength of rat skin incisions (tested both in the fresh state and after formalin fixation). These agents also enhanced subcutaneous polyvinyl alcohol sponge reparative tissue collagen accumulation, generally by a factor of two. Histologic features of treated and control incisions were similar. In contrast, the reparative tissue of treated sponges contained more neutrophils, macrophages, capillaries, and collagen. These experimental data thus confirm our previous studies, as well as our hypothesis, and extend these observations of enhanced wound healing to specific fractions of the bacterial cell wall.

Unlabelled: Somatostatin and its analogs are used clinically to treat patients with pancreatitis. To evaluate the effects of i.v. Sandostatin (SNST) on rats with trauma-induced acute pancreatitis, 130 male Sprague-Dawley rats (300-350 g) underwent celiotomy, controlled direct pancreas contusion, and central i.v. line insertion under ip sodium pentobarbital anesthesia. The rats were divided randomly into control (IA, IIA, and IIIA) and SNST-treated (IB, IIB, and IIIB) groups. The basic infusion solution contained 4.8% glucose, vitamins, and electrolytes. For groups IA and IB, the infusion rate was 24 ml/kg/day, while it was 240 ml/kg/day for groups IIA, IIB, IIIA, and IIIB. SNST administration was 6 micrograms/kg/hr i.v. for groups IB and IIB during the first postoperative day, while group IIIB received 6 micrograms/kg/hr i.v. for 4 days. Surviving rats were euthanized after 4 days. All survivors and nonsurvivors were autopsied. In all groups, severity of pancreatitis, fat necrosis, and ascites were greater in the nonsurvivors (P < 0.005 in each case). Mortality rates were consistently lower in the SNST groups: IA (76%) vs IB (52%), IIA (71%) vs IIB (50%), and IIIA (63%) vs IIIB (50%). Because individual group mortality rates were not affected by volume of infusate given or length of time SNST was administered, the results of all control and all SNST rats were combined; there was a statistically significant lower mortality in the SNST-treated rats (51 vs 71%, P < 0.04)., Conclusion: Intravenous administration of Sandostatin to rats following induction of severe acute traumatic pancreatitis significantly ameliorates the course of the disease.

Objective: To test the hypothesis that receipt of housing subsidies by poor families is associated with improved nutritional status of their children., Design: Cross-sectional study., Setting: Pediatric emergency department of an urban municipal hospital., Patients: Convenience sample of 203 children younger than 3 years and their families who were being seen during one of twenty-seven 24-hour periods., Main Outcome Measures: Anthropometric indicators (z scores of weight for age, weight-for-height, and height-for-age), and the proportion of children with low growth indicator (weight-for-height below the 10th percentile or height-for-age below the fifth percentile, or both, of the reference population)., Results: Multivariate analysis controlling for demographics and program participation showed that receipt of housing assistance contributed significantly to z scores for weight-for-age (P = .03) and weight-for-height (P = .04). The risk of a child's having low growth indicators was 21.6% for children whose families were on the waiting list for housing assistance compared with 3.3% for those whose families received subsidies (adjusted odds ratio = 8.2, 95% confidence interval = 2.2 to 30.4, P = .002), Conclusion: Receiving a housing subsidy is associated with increased growth in children from low-income families, an effect that is consistent with a protective effect of housing subsidies against childhood undernutrition.

Objectives: Documented monitoring was used to evaluate prospectively (1) the level of compliance among infants in whom cardiorespiratory monitoring was clinically indicated and (2) factors that might influence compliance: diagnosis, socioeconomic status, maternal age and education, and alarms., Study Design: Sixty-seven infants (51% female, 49% term) were sequentially enrolled, and monitoring was prescribed for the following indications: siblings of sudden infant death syndrome victims (16%), apnea of prematurity (45%), and apparent life-threatening events or apnea of infancy (39%). Demographic data, alarm and event data, and a summary report of monitor use from the first monitor download were obtained., Results: Maternal age, education, and insurance status did not differ significantly by indication for monitoring. The median number of monitor alarms per 10 hours of use was 0.7 for apnea or bradycardia and 0.6 for loose lead alarms. Monitors were available for use in the home from 2 to 106 days (median, 11 days). Median hours of monitor use per full day in the home was 15.5 hours. Of 67 infants, 58 used the monitor for at least part of every day in the home. The number of hours of monitor use per day did not differ significantly by diagnostic category, chronologic age, alarms, maternal age, education, or insurance type. This study population of infants at increased risk of sudden infant death syndrome had excellent compliance; 75% of the infants were monitored more than 10.5 hours per day, and 25% were monitored more than 21 hours per day., Conclusions: Documented monitoring provides an objective measure of compliance. These data provide a potential goal for level of compliance with home cardiorespiratory monitoring.

Wound healing of sternal incisions and midline or paramedian abdominal incisions was studied at 2 weeks postoperatively in three groups of dogs. Group 1, 10 dogs, had harvesting of bilateral internal thoracic arteries, superior epigastric arteries, and inferior epigastric arteries. Group 2, 5 dogs, had removal of the same arteries, but the superior and inferior epigastric arteries were harvested through paramedian rather than midline incisions. Group 3, 5 dogs, served as control and had median sternotomies and midline abdominal incisions only. All wounds healed without complication. Wound breaking strength of the skin of the chest incisions was significantly greater (p < 0.05) in the control group (group 3) (52.6 lb) compared with groups 1 (38.0 lb) and 2 (34.8 lb). Wound breaking strength of the skin of the abdominal incisions was significantly greater (p < 0.05) in group 2 (50.4 lb) when paramedian incisions were made compared with group 1 (35.1 lb). Hydroxyproline content was similar for all groups and all incisions. We conclude that abdominal wound breaking strength is significantly greater when paramedian incisions are performed to harvest the inferior epigastric arteries. Harvesting bilateral internal thoracic, superior epigastric, and inferior epigastric arteries may lower sternal wound breaking strength.

Based on clinical observations, we hypothesized that prolonged parenteral nutrition (in contrast to enteral nutrition) is detrimental after major hepatic resection. Male Sprague-Dawley rats (300 to 380 g) anesthetized with intraperitoneal sodium pentobarbital had 70% hepatic resection and jugular vein and gastrostomy catheterizations using aseptic techniques and were divided randomly into three groups: (1) total parenteral nutrition (TPN) (nutrients via central vein), (2) total enteral nutrition (TEN) (identical nutrients via gastrostomy), and (3) standard oral feeding (SOF) (chow and water ad libitum). Unused catheters were plugged. In the first set of experiments (n = 42), nutrient intake was formulated to approximate the nutritional intake of normal rats, 216 kcal/kg/d. Infusate was 15% glucose, 4.5% amino acids, electrolytes, trace minerals, vitamins, and 20% fat emulsion given half-strength the first day, three-fourths strength the second day, and full strength thereafter. On postoperative day 7, surviving rats were killed. Mortality prior to day 7 was very high (68%) in the TPN group and low in the TEN (9%) and SOF (9%) groups (p < 0.005). Among survivors, the serum albumin level was lowest (p < 0.002) and serum bilirubin level (p < 0.025) and wet weight of regenerated liver (p < 0.002) highest in the TPN group. However, the livers in TPN rats appeared pale and were found to be abnormal histologically with markedly diminished glycogen and amphophylic hepatocyte cytoplasm, and their spleens were enlarged (by a factor of two). The high mortality of TPN rats was seen whether the fat emulsion was given as a bolus daily, continuously as part of the infusate, or not included as part of the TPN regimen. In the next series (n = 70), nutrient concentrations, volumes, and rates of infusion were varied. There was a high correlation between caloric (r2 = 0.831, p < 0.0006), glucose (r2 = 0.598, p < 0.02), and amino acid (r2 = 0.619, p < 0.03) intakes and mortality in the TPN group: at 140 kcal/kg/d, none died; at 178 kcal/kg/d, 50% to 62% died; and at 230 kcal/kg/d, 80% died. No TEN rat died. In conclusion, 70% hepatectomized rats fed enterally with nutrients approximating the intake of normal rats do well and survive. In sharp contrast, mortality is very high when identical nutrients are infused parenterally. By reducing the levels of nutrients given parenterally, survival improves significantly.

Objective: To study whether alcoholic workers had seen physicians during the year they were identified by their company, whether they recalled physicians' warnings about drinking, and whether such warnings affected outcomes 2 years later., Design: Workers were interviewed at intake and 2 years later: subgroups who did and did not see physicians and who did and did not recall warnings were compared., Setting: A company-union employee assistance program., Participants: Two hundred problem drinkers, newly identified on the job, predominantly male, blue-collar workers., Outcomes: Drinking, drunkenness, average daily alcohol consumption, and impairment score., Results: Among the 200 participants, 74% saw physicians in the index year; only 22% recalled warnings. Recall of a warning was associated with liver disease, continued drinking while ill, supervisors' job warnings, older age, and marijuana use. Two years later, those warned were more likely to be abstaining, and sober, and were less impaired., Conclusions: Recalling a physician's warning at intake into alcoholism treatment was associated with better prognosis 2 years later. However, among this group of employees whose drinking was serious enough to be identified on the job, fewer than a quarter recalled physicians' warnings, even though more than three quarters had seen physicians in the year preceding intake.

Background: Employee-assistance programs sponsored by companies or labor unions identify workers who abuse alcohol and refer them for care, often to inpatient rehabilitation programs. Yet the effectiveness of inpatient treatment, as compared with a variety of less intensive alternatives, has repeatedly been called into question. In this study, anchored in the work site, we compared the effectiveness of mandatory in-hospital treatment with that of required attendance at the meetings of a self-help group and a choice of treatment options., Methods: We randomly assigned a series of 227 workers newly identified as abusing alcohol to one of three rehabilitation regimens: compulsory inpatient treatment, compulsory attendance at Alcoholics Anonymous (AA) meetings, and a choice of options. Inpatient backup was provided if needed. The groups were compared in terms of 12 job-performance variables and 12 measures of drinking and drug use during a two-year follow-up period., Results: All three groups improved, and no significant differences were found among the groups in job-related outcome variables. On seven measures of drinking and drug use, however, we found significant differences at several follow-up assessments. The hospital group fared best and that assigned to AA the least well; those allowed to choose a program had intermediate outcomes. Additional inpatient treatment was required significantly more often (P less than 0.0001) by the AA group (63 percent) and the choice group (38 percent) than by subjects assigned to initial treatment in the hospital (23 percent). The differences among the groups were especially pronounced for workers who had used cocaine within six months before study entry. The estimated costs of inpatient treatment for the AA and choice groups averaged only 10 percent less than the costs for the hospital group because of their higher rates of additional treatment., Conclusions: Even for employed problem drinkers who are not abusing drugs and who have no serious medical problems, an initial referral to AA alone or a choice of programs, although less costly than inpatient care, involves more risk than compulsory inpatient treatment and should be accompanied by close monitoring for signs of incipient relapse.

Starting total parenteral nutrition (TPN) the day after acute surgical stress has beneficial effects on body weight, nitrogen balance, and colonic anastomosis bursting pressure in normally nourished rats. In view of the reported favorable utilization of high-concentration branch-chain amino acids (BCAA) following severe stress, we compared enteral (TEN) to parenteral (TPN) nutrient infusions containing increased BCAA starting the day of operation. Twenty-four male Sprague-Dawley rats, in two groups paired by weight under IP pentobarbital anesthesia underwent jugular vein catheter (CVP) insertion, laparotomy, gastrostomy, colon anastomosis, dorsal skin incision and SC polyvinyl alcohol sponge insertion. The rats were maintained for 6 days with continuous IV infusion in the TPN group (gastrostomy plugged) and continuous gastric infusion for the TEN group (CVP plugged). Urine and feces were collected daily. The infusions contained 1000 to 1002 Kcal, 847 to 845 nonprotein Kcal, 38 to 39 g of amino acids, 206 to 209 g of carbohydrates, and 2.8 to 2.9 g of rat per liter in the TEN and TPN, respectively, with identical ratios of dietary essential amino acids to nonessential amino acids (52/48), and 28.34% BCAA in the TPN and 33.10% BCAA in the TEN. There were 491 mg/100 mL of glutamine in the TEN and 170 mg of glutamic acid in the TPN. Amino acids were infused at 8.59 g/kg per day for TEN and 8.34 g/kg per day for TPN. The vitamins, minerals, and trace minerals were essentially the same in the TEN and TPN except for the absence of iron, iodine, selenium, and molybdenum in the TPN.(ABSTRACT TRUNCATED AT 250 WORDS)

Increases in cocaine use have created a new and challenging cohort of problem drinkers with dual or multiple addictions. As part of a randomized trial comparing alternative alcoholism treatments at a 10,000-employee industrial plant, we interviewed 224 new alcoholic clients of an employee assistance program (EAP); 40% used cocaine during the 6 months just prior to EAP intake. Compared to employees reporting no recent cocaine use, the cocaine users were younger, less often married and reported heavier drinking and more alcohol-related problems, on the job and off. Even after controlling for demographic and occupational factors, and drinking indicators, cocaine users reported more binges (being drunk 24 hours or more), more blackouts (marginally significant, p = .06), more absenteeism and more warnings about unacceptable job performance. Alcoholic EAP clients who use cocaine appear to engage in riskier drinking and to have more trouble on the job than do those who report no cocaine use, and this seems to be a difference specifically attributable to their use of cocaine.

Improved healing occurs in nutritionally depleted rats given early postoperative compared with delayed feeding. The present study was designed to test the hypothesis that delay in postoperative feeding of rats normally nourished at the time of operation would also be detrimental to wound healing. Fully nourished rats weighing 288 to 342 g were divided into three groups (10 rats per group). All rats had central vein catheters inserted, celiotomy with division and reanastomsis of the colon and dorsal skin incisions, under ip pentobarbital anesthesia. With no oral intake allowed postoperatively, group 1 rats were maintained in iv 5% Dextrose electrolytes and vitamins (5% DSV); group 2 was given the 5% D/SV until the third postoperative day when they were placed on TPN (4.5% amino acids 15% Dextrose, 10% Intralipids); and group 3 was given TPN from the first postoperative day. Rats were sacrificed 6 days postoperatively and final weight, skin wound breaking strength (WBS) and colon anastomosis bursting pressure (CBP) were measured. Findings were % weight change -27.8 +/- 1.5 for Group 1, -12.6 +/- 1.0 for Group 2, and -6.9 +/- 8 for group 3 (p less than 0.0001). Wound measurements for STS on fresh specimens were 88.6 +/- 10.0 g for group 1, 89.1 +/- 8.4 g for group 2, and 87.1 +/- 11.1 g for group 3. WBS for formalin-fixed specimens were 313.5 +/- 29.7 g for group 1, 323.4 +/- 38.4 g for group 2, and 382 +/- 25.2 g for group 3 (NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Ninety-six adult Leghorn chickens each had the flexor profundus tendon in each middle toe sharply divided in Zone II with immediate repair (pentobarbital, ketamine anesthesia). Animals were then randomly assigned to receive unsupplemented standard chick chow or the chow supplemented with vitamin A (150,000 IU/kg chow), Vitamin E (1000 IU/kg chow), or beta-carotene (90 mg/kg chow). Eight animals from each of the four groups were examined at 7, 30, or 45 days post repair. After sacrifice, in situ composite wound breaking strength was measured in the amputated toe by constant speed tensiometry. Vitamin A-supplemented animals demonstrated breaking strength more than double that of control at each postoperative test day, while those animals receiving supplemental Vitamin E had breaking strength less than half that of control at Day 7 and Day 45. These results are statistically significant. Tensiometry curves differed markedly at all time points among the groups: Vitamin A curves being broader, higher, and having more spikes. These differences in the tensiometry curves, both qualitative and quantitative, may be due to differences in intrinsic tendon healing or to differences in adhesion formation or a combination of both. beta-Carotene supplementation had modest effect. We conclude that supplemental dietary vitamin A increases the breaking strength of composite tendon wounds and that supplemental dietary vitamin E decreases it.

To test our hypothesis that supplemental vitamin A would mitigate the impaired healing that occurs in tumor-bearing animals, six groups of C3H mice, eight per group, eating a standard commercial mouse chow ad libitum that supports normal growth, reproduction, and longevity were innoculated with 200,000 C3HBA cells. When tumors measured approximately 6 mm in diameter, the mice were anesthesized and wounded (dorsal skin incisions and subcutaneous polyvinyl alcohol sponges). Twenty-four hours later, two groups (one continued on the chow and the other started on the chow supplemented with 150,000 IU vitamin A/kg chow) underwent local tumor irradiation; two groups, one ingesting the chow, the other the vitamin A supplemented chow, were started on cyclophosphamide therapy; two groups, one ingesting the chow, the other the vitamin A supplemented chow, received neither local tumor irradiation nor cyclophosphamide therapy. An additional two groups ingesting the chow, one group neither innoculated with tumor nor wounded, the other wounded by not innoculated, served as controls. Wound breaking strength and sponge reparative collagen accumulation (assessed by hydroxyproline proline measurement) were used as indicators of wound healing. The mice were killed 12 days after wounding. Tumor presence decreased wound breaking strength and sponge hydroxyproline content; these effects were largely negated by supplemental vitamin A. Local tumor irradiation diminished the adverse effect of tumor on sponge reparative collagen content but to a lesser extent than the supplemental vitamin A. Supplemental vitamin A added to the irradiation effect on healing but irradiation did not add to the vitamin A effect. Cyclophosphamide, a systemic radiomimetic anti-tumor agent, did not alter the impaired wound healing of the tumor-bearing mice. Supplemental vitamin A mitigated the impaired wound healing in the cyclophosphamide-treated tumor-bearing mice. Supplemental vitamin A also moderated the effects of wounding, tumor, and tumor therapies (local irradiation and cyclophosphamide) on the increase in adrenal size, leukopenia, thrombocytopenia, and thymic involution (except the last was not moderated in the cyclophosphamide-treated tumor-bearing rats). The splenic enlargement in the untreated tumor-bearing wounded rats and in those treated with cyclophosphamide was lessened by supplemental vitamin A. We hypothesize that these anti-stress effects of vitamin A underlie, in part, its action in mitigating the impaired wound healing of tumor-bearing mice, including those treated by local irradiation or cyclophosphamide. These findings have implications for the care of patients with malignant tumors.

Acute radiation injury leads to thymic involution, adrenal enlargement, leukopenia, thrombocytopenia, gastrointestinal ulceration, and impaired wound healing. The authors hypothesized that supplemental vitamin A would mitigate these adverse effects in rats exposed to acute whole-body radiation. This hypothesis was based on previous experiments in their laboratory that showed that supplemental vitamin A is thymotropic for normal rodents and lessens the thymic involution, lymphopenia, and adrenal enlargement that follows stress, trauma, and neoplasia, largely obviates the impaired wound healing induced by the radiomimetic drugs streptozotocin and cyclophosphamide, lessens the systemic response (thymic involution, adrenal enlargement, leukopenia, lymphocytopenia) to local radiation, and shifts the median lethal dose (LD50/30) following whole-body radiation to the right. To test their hypothesis, dorsal skin incisions and subcutaneous implantation of polyvinyl alcohol sponges were performed in anesthetized Sprague-Dawley rats at varying times following sham radiation or varying doses of whole-body radiation (175-850 rad). In each experiment, the control diet [which contains about 18,000 IU vit. A/kg chow (3 X the NRC RDA for normal rats)] was supplemented with 150,000 IU vit. A/kg diet beginning at, before, or after sham radiation and wounding or radiation and wounding. The supplemental vitamin A prevented the impaired wound healing and lessened the weight loss, leukopenia, thrombocytopenia, thymic involution, adrenal enlargement, decrease in splenic weight, and gastric ulceration of the radiated (750-850 rad) wounded rats. This was true whether the supplemental vitamin A was begun before (2 or 4 days) or after (1-2 hours to 4 days) radiation and wounding; the supplemental vitamin A was more effective when started before or up to 2 days after radiation and wounding. The authors believe that prevention of the impaired wound healing following radiation by supplemental vitamin A is due to its enhancing the early inflammatory reaction to wounding, including increasing the number of monocytes and macrophages at the wound site; possible effect on modulating collagenase activity; effect on epithelial cell (and possible mesenchymal cell) differentiation; stimulation of immune responsiveness; and lessening of the adverse effects of radiation.

While comparing the effects on wound healing of a heated scalpel with those of the cold scalpel, we discovered that inoculation of rat skin incisions with a strain of Staphylococcus aureus dramatically accelerated the gain in wound strength. The accelerating effect was evident four days postoperatively, was maximal at seven to ten days, and was still present at 28 days. The accelerating effect was correlated with the number of S aureus organisms introduced into the wound, and was found in conventional rats and rats germ free up to the time of monocontamination with S aureus. There was no evidence of infection on gross examination; on histologic examination an occasional microabscess was seen in some rats. There may be both local and systemic mechanisms underlying the S aureus accelerating effect. Seven strains of S aureus with varying characteristics demonstrated the wound-healing accelerating effect. In sharp contrast, Staphylococcus epidermidis (three strains), Staphylococcus hominis (one strain), and Pseudomonas aeruginosa (two strains) did not show this effect. The increases in wound healing due to S aureus were substantially greater than reported previously for any nutritional supplement, drug, or other chemical or physical agent.

The effect of 6-day dietary arginine supplementation on the weight gain, blood glucose, thymus weight, thymic lymphocyte content, and in vitro thymic lymphocyte immune reactivity was studied in obese (C57BL/6J-OB/)B) and heterozygous lean mice. Control mice were fed a commercial laboratory chow (1.8% arginine content) and drank tap water, while supplemented mice were given 0.5% arginine in the chow and 0.5% arginine solution for drinking. All mice ate and drank ad libitum. Supplemental arginine significantly decreased the weight gain (1.2 g vs. 2.2 g, p less than 0.01) and blood glucose levels (303 mg% vs 236 mg%, p less than 0.02) of the OB/OB mice; no such effects were noted in the lean heterozygotes, all of which had normal blood glucose levels. OB/OB mice had thymus glands which weighed less and contained significantly fewer lymphocytes than their lean littermates. In vitro mitogen-stimulated thymic lymphocyte protein synthetic rates were equal in chow-fed lean and OB/OB mice. In both groups, supplemental arginine significantly increased thymus weight, the number of thymic lymphocytes per gland, and thymic lymphocyte immunoreactivity in vitro. The hormonal secretagogue activity of arginine on the pituitary may explain its beneficial effects on the rate of weight gain, hyperglycemia, and depressed thymic immune function of OB/OB mice.