Effects of specific nutrients on the immune response. Selected clinical applications

The Nutritional Status of Pediatric Patients with Single Ventricle Undergoing a Bidirectional Glenn Procedure

Single ventricle (SV) physiology is associated with growth retardation in children. The nutritional status of pediatric patients with SV undergoing a bidirectional Glenn (BDG) procedure vitally affects the feasibility of the next operation stages. To explore the nutritional status and to identify specific anthropometric parameters relevant to short-term surgical outcomes in children with SV after the BDG procedure, this study included 151 patients who underwent the BDG procedure. Anthropometric assessments and Infant and Child Feeding Index (ICFI) scores were used to evaluate nutritional status. There was a significant statistical correlation between ICFI and malnutrition in both the height-for-age Z-score (HAZ) and weight-for-age Z-score (WAZ) groups (P < 0.05). The clinical data, including ventilation time, nosocomial infection presence, pressure injury presence, peritoneal dialysis status, and total intensive care unit days, after BDG surgery were significantly different among the HAZ groups (P < 0.05), while nosocomial infection was different among the WAZ groups (P < 0.05). Children after BDG procedure had a high incidence of malnutrition, in addition to disease factors, the type and frequency of dietary intake were also important factors leading to worse clinical outcomes during hospitalization. Therefore, it is vital to maintain an optimal nutritional status in infants with SV who are undergoing a series of surgical procedures.

Lower weight-for-age z score adversely affects hospital length of stay after the bidirectional Glenn procedure in 100 infants with a single ventricle

OBJECTIVE

Poor growth has been described in infants with a single ventricle; however, little is known regarding its effect on surgical outcomes. We sought to assess the effect of nutritional status at the time of the bidirectional Glenn procedure on short-term outcomes.

METHODS

We performed a retrospective case series of children who underwent the bidirectional Glenn procedure at our institution between January 2001 and December 2007. Anthropometric measurements were recorded at the time of neonatal admission and the bidirectional Glenn procedure. Data from preoperative echocardiograms and cardiac catheterization were recorded. The primary outcome variable was length of hospital stay.

RESULTS

Data on 100 infants were included for analysis. Age at the time of the bidirectional Glenn procedure was 5.1 months (range, 2.4-10 months). The median weight-for-age z score at birth was -0.4 (range, -2.6 to 3.2), and by the time of the bidirectional Glenn procedure, it had decreased to -1.3 (range, -3.9 to 0.6). In multivariable modeling longer postoperative hospital stays were predicted by lower weight-for-age z score (P = .02), younger age (P < .001), being fed through a gastrostomy tube (P = .01), and undergoing concomitant aortic arch reconstruction (P < .001) at the time of the bidirectional Glenn procedure.

CONCLUSIONS

There is suboptimal weight gain between neonatal discharge and the bidirectional Glenn procedure. A lower weight-for-age z score and younger age at the time of the bidirectional Glenn procedure affects length of hospital stay independent of hemodynamic or echocardiographic variables.

Histopathology of the thymus

The thymus is a primary lymphoid organ that manifests dynamic physiological changes as animals age in addition to being exquisitely sensitive to stress and toxic insult. It is typically the first lymphoid tissue to respond to immunotoxic xenobiotics, with the first change being loss of cortical lymphocytes by apoptosis. This is followed by removal of the apoptotic cellular debris and, in the absence of recovery, may lead to loss of the cortico-medullary demarcation and organ atrophy. Nonneoplastic proliferative changes include focal lymphoid hyperplasia and proliferation of medullary epithelial cells, often with formation of ribbons, cords, or tubules. Thymomas are relatively rare tumors that exhibit a wide spectrum of morphologic types but do not metastasize. Thymic lymphomas are common in some mouse strains and can become leukemic with hematogenous spread throughout the body.

Micronutrients and child health: studies in international nutrition and HIV infection

Increasing data link micronutrient deficiencies to excess childhood morbidity and mortality, and similar relationships have been noted in the study of nutrition and HIV infection. We review epidemiologic studies that have examined the relationship between micronutrient deficiencies and health outcomes in childhood and HIV infection, as well as clinical trials of micronutrient supplementation. Vitamin A supplementation among communities at risk of deficiency effectively reduces mortality and morbidity in children younger than age 5, and vitamin A may be especially effective in HIV-infected children. Vertical transmission of HIV has not to date been affected by maternal micronutrient supplementation. In children with poor dietary zinc intake and/or bioavailability, zinc supplementation reduces the incidence and severity of diarrheal diseases, as well as the occurrence of pneumonia. Vitamin A therapy has not been associated with improved growth, whereas some trials have shown that zinc supplementation is associated with greater increments in height. Further trials of micronutrient supplementation are warranted.

R3230AC rat mammary tumor and dietary long-chain (n-3) fatty acids change immune cell composition and function during mitogen activation

Because anticancer immunity declines progressively with tumor growth, a major focus of current research in tumor immunology is the development of means to stimulate the host immune system. This study determined the effects of dietary long-chain (n-3) fatty acids and tumor burden on immune cell phospholipid composition and membrane-mediated immune defense in rats implanted with the R3230AC mammary adenocarcinoma. Fischer 344 rats (145 +/- 2 g) were fed one of two semipurified diets (20 g/100 g fat) for 21 d before and 17 d after tumor implantation. Diets provided long-chain (n-3) fatty acids at 0 or 50 g/kg of total fat. Mammary tumor growth was 31% lower (P = 0.1) in rats fed long-chain (n-3) fatty acids. Dietary long-chain (n-3) fatty acids had beneficial effects on several host immune defenses, including activation of CD8(+) T cells and type-1 cytokine (interferon-gamma and tumor necrosis factor-alpha) production (P < 0.05). Upregulated immune function in tumor-bearing rats fed the high (n-3) diet occurred concurrently with specific changes in the major membrane phospholipids phosphatidylcholine and phosphatidylethanolamine in high (n-3)-fed rats. Because membrane composition plays a critical role in immune function, additional work is needed to determine the relationship between alterations in the phospholipid composition of immune cells during cancer and subsequent upregulation of host defense in the tumor-bearing state.

T lymphopenia in genetically obese rats

Although obese animals are more susceptible to infection, the underlying causes are not fully known. In this study, long-term measurements were made of lymphocyte subsets in peripheral blood, spleen, and thymus in genetically obese Zucker (fa/fa) rats. Blastogenic response of splenocytes to mitogens was also examined. fa/fa rats developed obesity, hyperlipidemia, and hyperinsulinemia after 5 weeks of age. Flow cytometric analysis revealed that T cells in peripheral blood, spleen, and thymus were all reduced significantly in obese rats after 8 weeks of age compared to nonobese (Fa/-) littermates. All T-cell subsets examined, including CD4+ and CD8+ T cells, were similarly reduced in spleen and thymus as well as in peripheral blood with advance in age. In addition, proliferative responses of splenocytes to mitogens were significantly low in obese rats. These results indicate that long-term obesity may reduce the size of the T-cell pool and impair the responsiveness of splenocytes in rats.

The blood constituents of gossypol-treated, protein-malnourished Wistar rats

Gossypol was administered in Goya olive oil to low protein-fed (LP, protein-malnourished) and normal protein-fed (NP, control) adult male albino Wistar rats for 4 and 8 weeks at 20 mg/kg body weight/rat/day. At the end of the experiment, the rats were killed and blood was drawn from the rats by cardiac puncture and subjected to hematological and biochemical analyses. The data obtained were analyzed by two-way analysis of variance (ANOVA). The interaction of the treatments produced significant effects on serum levels of sodium, potassium, cholesterol, triglyceride, urea, glutamate oxalate transaminase, glutamate pyruvate transaminase, amylase and blood platelet count (P < 0.001), and uric acid (P < 0.01). Significant effects were produced on serum phosphate, albumin and blood reticulocyte count (P < 0.05) but not on packed cell volume, red blood cell count, white blood cell (WBC) count and WBC differential counts, hemoglobin concentration, creatinine, creatinine phosphokinase and alkaline phosphatase (P < 0.05). The administration of gossypol reduced the level of transaminases, cholesterol and uric acid in LP and NP rats, increased the levels of triglycerides, amylase, platelet and reticulocyte count in LP rats but decreased them in NP rats. The implications of the findings are discussed.

Histopathology of the immune system as a tool to assess immunotoxicity

Immunotoxicology studies the undesired effects of interactions between xenobiotics and the immune system, mainly in toxicity experiments in rodents. The histopathology of the lymphoid organs is a cornerstone in such studies. In this review we describe practical aspects of sampling lymphoid organs and subsequent tissue processing and application of conventional and advanced histologic techniques. Thereafter, some aspects of proper reading and interpretation of histopathology is discussed, in relation to modifying factors such as age, sex, strain of animals, housing conditions, and nutritional status. These factors can substantially confound the outcome and interpretation of experiments, due to the highly dynamic characteristics of the immune system. Immunotoxicity tests are normally performed in a tiered approach. We describe the screening tier in the rat species that has been developed in the National Institute of Public Health and Environmental Protection, Bilthoven, The Netherlands, and illustrate the value of histopathology by an example of immunotoxicity testing of pesticides. Subsequently, the tiered approach in the mouse species followed by the National Toxicology Program in the USA, is described. In the evaluation of chemicals with suspected immunotoxic potential using this approach, histopathology proved to be less sensitive in 'flagging' immunotoxicity. This may be related to the lower doses that are applied in this toxicity design, because at higher doses histopathology is a sensitive indicator of toxicity. A global description of pathologic alterations after toxic insult is given, followed by representative examples taken from immunosuppressive drugs--the cytostatic agent 5-fluorouracil, and drugs interfering with cytokine expression, namely, Cyclosporin A, FK-506, and Rapamycin.

Mechanisms of chromium carcinogenicity and toxicity

Chromium, like many transition metal elements, is essential to life at low concentrations yet toxic to many systems at higher concentrations. In addition to the overt symptoms of acute chromium toxicity, delayed manifestations of chromium exposure become apparent by subsequent increases in the incidence of various human cancers. Chromium is widely used in numerous industrial processes, and as a result is a contaminant of many environmental systems. Chromium, in its myriad chemical forms and oxidation states, has been well studied in terms of its general chemistry and its interactions with biological molecules. However, the precise mechanisms by which chromium is both an essential metal and a carcinogen are not yet fully clear. The following review does not seek to embellish upon the proposed mechanisms of the toxic and carcinogenic actions of chromium, but rather provides a comprehensive review of these theories. The chemical nature of chromium compounds and how these properties impact upon the interactions of chromium with cellular and genetic targets, including animal and human hosts, are discussed.

Nutritional alterations in persons with HIV infection

Potential relationships among nutritional status, immune function and quality of life were examined in a convenience sample of 40 outpatient homosexual and bisexual males stratified into five categories, using modified Walter Reed Staging Criteria. Nutritional status was assessed by measuring height, weight, triceps skinfold thickness, arm circumference, nutrient intake and serum albumin. Immune status was evaluated by determining T-helper cell numbers and percentages. The Quality of Life test was used to obtain information about life quality. Nutritional assessment failed to show significant differences among groups with the exception that serum albumin levels were reduced in persons with AIDS. The significance of change in serum albumin in regard to nutritional status is unclear, since serum albumin is affected by a number of non-nutritional factors, such as hydration status and liver function. The study also revealed a significant decline in T-helper percentages, but not absolute T-helper cell numbers as a function of disease stage. There were no statistically significant differences between the quality of life scores with respect to each grouping. These data suggest that asymptomatic patients as well as those with ARC or stable AIDS are able to maintain body weight and composition.

Epidemiology of non-Hodgkin lymphoma in Connecticut. 1935-1988

BACKGROUND

During the past decades, there have been reports of increases in the incidence and mortality rates due to non-Hodgkin lymphoma (NHL) in many parts of the world. The risk factors responsible for the increasing incidence are largely unknown. This study provided an overview of the incidence pattern of NHL in Connecticut and generated hypotheses for additional investigation.

METHODS

This study was based on all the NHL cases reported to the Connecticut Tumor Registry (CTR) between 1935 and 1988. Crude, age-adjusted, and age-specific incidence rates of NHL were calculated for each sex. Age-adjusted incidence rates were calculated by the direct method standardized to the 1970 United States standard million population. The data are presented by calendar year and cohort year of birth to examine the secular trends and birth cohort effects. Racial information was not coded before 1957 and is of uncertain validity until the early 1970s; therefore, racial analysis was restricted to 1970-1988. Analyses by histologic subtypes and by anatomic sites were restricted to the last 3 decades (1960-1988) because more accurate classification systems were used during this time.

RESULTS

A total of 11,326 newly diagnosed cases of NHL were included in the study. Of them, 5866 (52%) were diagnosed in men and 5460 (48%) were diagnosed in women. The study results indicated that the incidence rate of NHL has been increasing during the past decades for men and women, whites and blacks, nodular NHL and diffuse NHL, disease originating from lymph nodes and disease originating from other sites, and in all age groups, especially the older age groups. Birth cohort examination did not show any indication of a decline or levelling off in incidence rates among recent birth cohorts. Age-specific incidence rates in both sexes suggested that the rates increase with age, with a sharp increase beginning at 50 years of age and peaking at 80 years of age. Men had a 30% higher incidence rate than women, and whites had approximately 1.5 times the age-adjusted incidence rate of blacks.

CONCLUSIONS

The results indicated that the incidence rate of NHL has been increasing in Connecticut during the past decades and is likely to continue to rise in the coming years. Analytical epidemiologic studies are needed to examine the risk factors that might account for the increase in NHL.

Effect of folic acid deficiency upon lymphocyte subsets from lymphoid organs in mice

1. Three groups of weanling C57BL/6 female mice were fed one of two folate-deficient diets (0 and 0.1 mg folic acid/kg diet) or a normal folate-containing diet (2 mg folic acid/kg diet) for 8 weeks. A control pair-fed group was introduced with the most severe folate-deficient diet. Seven mice were fed the 0 mg folic acid/kg diet for 8 weeks, then rehabilitated (R) on the 2 mg folic acid/kg diet for 10 days. 2. Mice fed 0 mg folic acid/kg diet were severely folate-deficient (SFD), whereas mice fed 0.1 mg folic acid/kg diet were moderately folate-deficient (MFD), as shown by their folate status parameters. 3. Thymus weight, thymocyte content and positive immature CD4+8+ cells were decreased in SFD mice compared to controls. These values were normalized after 10 days of rehabilitation. 4. Mesenteric lymph node cells were apparently not affected by folate deficiency. 5. The proportion of Thy-1+ splenocytes was mildly lower in SFD mice than in controls. In R mice, mean spleen weight and spleen cellularity were increased compared to the other groups, but the proportions of Thy-1+, CD4+8- and CD4-8+ cells were markedly lower than control values.

Gay men's perceptions and responses to AIDS

Gay men continue to be the largest group in Canada developing AIDS. They have responded to this threat on a personal and community level. The purpose of this study was to explore the perceptions of gay men about AIDS, and how they responded to these perceptions. Data were gathered through unstructured interviews with 34 healthy gay men, from participant observations chosen from logs that described nursing interactions with gay men who had AIDS, and fieldnotes collected during AIDS education programmes with health care workers and gay men. Using constant comparative analysis, a substantive conceptual framework was developed. Trusting was identified as the basic social psychological process that determined how gay men responded to AIDS. AIDS was perceived by all gay men in this study to threaten their own health and their acceptance by society. Variables identified behaviour, ranging from denial of personal risk to taking leadership roles in organizations to fight AIDS related to the trusting theory. This theoretical explanation of gay men's responses provides direction for programmes to educate gay men about HIV-related diseases, as well as to support those who acquire the HIV.

Enhancement of immune status by high levels of dietary vitamin B-6 without growth inhibition of human malignant melanoma in athymic nude mice

The effects of dietary vitamin B-6 supplementation on the development of human malignant melanoma (M21-HPB) xenografts and on in vitro responses of leukocytes were examined. Male athymic nude mice, five weeks old, were divided into two groups of 48 each and fed 20% casein diets containing pyridoxine (PN) at 4.1 (control diet) and 61.6 mg/kg diet for 10 weeks. After four weeks of dietary treatment, 20 animals from each dietary group were injected subcutaneously with 3 x 10(7) melanoma cells. After 4, 8, and 10 weeks of dietary regimen, animals from each group were killed and blood, liver, and spleen samples were obtained. Food consumption and mouse body weights were similar between groups, and no difference was noted in tumor incidence or volume. Noninjected and tumor-bearing mice given the PN 61.6 diet generally exhibited greater oxygen radical production by phagocytic cells from blood and spleen than did animals fed the PN 4.1 diet. Spleen and blood B lymphocyte proliferation in response to lipopolysaccharide (LPS) was enhanced (10 and 30%) in the noninjected animals given the PN 61.6 diet. In addition, tumor-bearing mice fed the PN 61.6 diet had significantly greater LPS-induced spleen cell proliferation at eight weeks when compared with mice consuming the PN 4.1 diet. Despite immune enhancement, tumor incidence and progression was not modified by a high level of dietary vitamin B-6. Therefore, it is tempting to speculate that tumor inhibition by high dietary vitamin B-6 may be mediated by T lymphocyte-dependent mechanisms that are lacking in these genetically immuno-deficient mice.

Effects of dietary fat and protein on DMH-induced tumor development and immune responses

Although in three different mouse tumor systems with corn oil as dietary fat we previously found that milk protein decreased tumor development compared with beef, the results were reversed in 1,2-dimethylhydrazine (DMH)-injected mice. The purpose of this study was to determine if the latter result was due to the protein source. BALB/c mice (n = 280) were divided into five diet groups and injected 10 times at weekly intervals with DMH (20 mg/kg wt) or saline. Four diets contained 11% protein (casein, milk, or beef) and 5% fat (corn oil or beef tallow), and the AIN-76A diet was used as a control diet. The source of fat was a significant modulator of tumor development. Corn oil markedly increased total tumor volume and the number of tumors per mouse compared with beef tallow. Its tumor-enhancing effects were evident when it was combined with milk but not with casein. In addition, significantly lower lymphoproliferation and T-cell cytotoxicity against colon tumor cell targets was associated with corn oil consumption, whereas nonfat milk as the protein source was related to normal oxidative burst capacity of phagocytes. These results demonstrate that the source of dietary fat, in addition to the protein source, has a profound effect on both tumor development and immune responsiveness in this animal tumor system.

Diet and opiate addiction: a quantitative assessment of the diet of non-institutionalized opiate addicts

The diet, weight and height of 38 non-institutionalized chronic opiate addicts have been assessed and compared to those of a random sample of the 20-35 year old general population of Canton Geneva, Switzerland. A history questionnaire was administered by specially trained dietitians. Results show that, after adjustment for age and alcohol intake, male addicts have the same caloric intake as non-addicts. However, addicts tend to replace foods that are rich in fat and proteins with foods rich in sucrose and relatively poor in vitamins and minerals. Beer is the major component of their much larger alcohol consumption. On the other hand, the body mass index (kg/m2) of the male addicts is within the normal range, suggesting this may not be a good indicator of their unbalanced diet. This study gives a quantitative assessment, in terms of nutrient intake, of the typical craving for sweet described by opiate addicts.

Evaluation of cancer patient leukocyte responses in the presence of physiologic and pharmacologic pyridoxine and pyridoxal levels

Peripheral blood samples from six cancer patients (five colon cancer, one lung cancer) and six healthy volunteers were tested in vitro for oxygen radical production by phagocytic cells and in assays of mitogen-induced lymphoblastogenesis at physiologic and pharmacologic concentrations of pyridoxine (PN, 1.8-96 nmol/ml) or pyridoxal (PL, 0.08-90 nmol/ml). Plasma levels of pyridoxal-5'-phosphate (PLP), 4-pyridoxic acid (4PA), pyridoxamine phosphate (PMP), and PL were also determined. Phagocytic cells from three patients showed significantly increased capacity for oxygen radical production when incubated in PL-, but not PN-supplemented media. Oxygen burst capacity of cells from healthy subjects was significantly enhanced by PN-, but not PL-enriched media. Lymphocyte responsiveness to phytohemagglutinin or pokeweed mitogen (PWM) stimulation showed a modest increase in cell activation in three patients as the concentration of PN was increased; with concanavalin A, two showed enhanced responsiveness. On the other hand, PL-supplementation resulted in greater cell proliferation only with PWM. The cancer patients had significantly lower plasma PLP, 4PA, and PMP levels when compared with the healthy volunteers. These data indicate that in the cancer patients and in a majority of the healthy volunteers, vitamin B-6 status was marginal or deficient and suggest that increasing PN or PL in vivo levels may augment functions related to cell-mediated immunity.

Selected AIDS beliefs, behaviors and informational needs of homosexual/bisexual men with AIDS or ARC

Due to the current absence of curative therapies, patients with AIDS or ARC (AIDS-Related Complex) rely on information to provide them with a sense of control over their lives [Institute of Medicine, National Academy of Sciences, Confronting AIDS: Directions for Public Health, Health Care and Research (1986)]. The purpose of this study was to describe AIDS beliefs, behaviors and informational needs of patients with AIDS or AIDS-related complex 7 years into the epidemic. Data were collected once using a modified version of the AIDS Beliefs and Behaviors Questionnaire (ABBQ) developed by McKusick et al. [Am. J. Public Hlth. 75, 493-496 (1985)] and Moran et al. [Oncol. Nurs. Forum (1988)]. Study results showed that 90% of outpatients (N = 30) at an internationally recognized AIDS medical center wanted more information about building their immune systems. Surprisingly few patients (10%) wanted explicit information about safe sexual behaviors, although 4 years into the epidemic, this information was a central concern [Moran, Unpublished Masters thesis (1986)]. Results suggests that nurses need to take a more active role in monitoring and addressing patients' changing informational needs.

The influence of host factors on the outcome of a viral infection

The clinician confronted with a patient that has an infectious disease, particularly one caused by a virus, faces a series of difficult problems: diagnostic confirmation of the infection, instituting appropriate therapy, duration of treatment, preventing secondary complications, and preventing transmission of the virus to susceptible animals. Yet, it is the complex relationship between the patient, as host to a pathogenic virus, the virus, and the environment that ultimately influences the clinical course of an infection. The ability to accurately prognose the outcome of any infection is, therefore, predicated on the clinician's awareness of biological and environmental variables that apply to the individual patient.