Assessment of the Clinical Impact of a Liver-Specific, BCAA-Enriched Diet in Major Liver Surgery

BACKGROUND

The relationship between nutrition and liver disease is relevant for the outcome after surgery. Patients with liver cirrhosis characteristically show protein-energy malnutrition with decreased levels of branched-chain amino acids (BCAA) and increased levels of aromatic amino acids.

MATERIALS AND METHODS

We conducted a prospective controlled clinical trial including 57 patients after liver transplantation or major liver resection surgery in order to test the effect of early postoperative nutrition on the outcome and nutrition profile of these patients. The test group received a dietetic program composed of ingredients naturally rich in BCAA (BCAA group), and the control group received standard hospital meals. Patient survival, liver function tests, subjective well-being, and a nutritional status including amino acid profiles were analyzed immediately and 14 days after major liver surgery (secondary end points). General health and well-being were assessed using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (primary end point).

RESULTS

In-depth analysis of amino acid profiles was performed for patients undergoing liver resection (n = 21) and liver transplantation (n = 36). Interestingly, amino acid profiles did not correlate with body mass index or the Model for End-Stage Liver Disease score. Patients scheduled for liver transplantation showed significantly lower levels of BCAA pretransplant compared to patients undergoing liver resection. Patients in the liver resection subgroup were more likely to benefit from the BCAA cuisine in terms of significantly higher food intake and subjective rating. The clinical liver function tests, however, did not show statistical difference between the BCAA group and the control group in the examination period of 14 days.

CONCLUSION

Our specifically designed BCAA-enriched diet resulted in greater patient satisfaction and compliance with nutrition. A larger trial or longer-term follow-up may be required to identify an effect on survival, recovery, surgical complications, protein profiles, and amino acid profiles.

Time Since Migration and HIV Risk Behaviors Among Puerto Ricans Who Inject Drugs in New York City

BACKGROUND

Among people who inject drugs (PWID) in the United States, those who initiated drug injection in Puerto Rico (immigrant Puerto Rican PWID) engage in more injection and sexual risk behaviors, and have higher HIV incidence than non-Hispanic whites.

OBJECTIVE

Understand the persistence of these HIV behaviors.

METHODS

In a cross-sectional study conducted in New York City (NYC) in 2012 (National HIV Behavioral Surveillance), PWID aged ≥18 years were recruited using Respondent-Driven Sampling, interviewed, and tested for HIV. Participants were categorized into 5 different groups: (1) US-born non-Hispanic PWID, (2) US-born Puerto Rican PWID, (3) recent immigrant Puerto Rican PWID (≤3 years in NYC), (4) medium-term immigrant Puerto Rican PWID (>3 and ≤10 years in NYC), and (5) long-term immigrant Puerto Rican PWID (>10 years in NYC). We examined the relationship between time since migrating on sexual and injection risk behaviors among immigrant Puerto Rican PWID, compared with U.S.-born Puerto Rican PWID and US-born non-Hispanic PWID. Adjusted odds ratios (aOR) and 95% confidence intervals (95% CI) were estimated using logistic regression.

RESULTS

A total of 481 PWID were recruited. In adjusted analyses using US-born non-Hispanic PWID as the comparison group, syringe sharing was significantly more likely among medium-term immigrants; and unprotected sex with casual partners was more likely among recent and long-term immigrants.

CONCLUSIONS

The risk-acculturation process for immigrant Puerto Rican PWID may be nonlinear and may not necessarily lead to risk reduction over time. Research is needed to better understand this process.

Factors associated with recent HIV testing among men who have sex with men in New York City

Understanding factors associated with recent HIV testing among men who have sex with men (MSM) is important for designing interventions to increase testing rates and link cases to care. A cross-sectional study of MSM was conducted in NYC in 2011 using venue-based sampling. Associations between HIV testing in the past 12 months and relevant variables were examined through the estimation of prevalence ratios (PR) and 95 % confidence intervals (CI). Of 448 participants, 107 (23.9 %) had not been tested in the past 12 months. Factors independently associated with not testing in the previous 12 months were: lack of a visit to a healthcare provider in the past 12 months (aPR: 2.5; 95 % CI: 1.9, 3.2); age ≥30 (adjusted PR: 1.9; 95 % CI: 1.4, 2.7); not having completed a bachelor's degree (aPR: 1.6; 95 % CI: 1.0, 2.4); and non-gay sexual identity (aPR: 1.4; 95 % CI: 1.0, 1.8); such MSM may be less aware of the need for frequent HIV testing.

Herpes simplex virus type 2 associated with HIV infection among New York heterosexuals living in high-risk areas

Herpes simplex virus type 2 (HSV-2) has been shown to increase the risk of sexual human immunodeficiency virus (HIV) transmission. A matched case-control design was used to examine the association between HSV-2 and HIV infection among heterosexuals in 'high-risk areas' (HRAs) in New York City (NYC). We identified NYC HRAs using HIV surveillance data on heterosexual-related adult HIV diagnoses and USA census data on household poverty. Heterosexuals who were socially or geographically linked to an HRA were recruited using respondent-driven sampling. HIV prevalence was 8.6% and HSV-2 prevalence was 80.1%. Only 6% of HIV-positives knew they were infected. HIV-positive cases were matched to HIV-negative controls on gender, race/ethnicity and age, and tested for antibody to HSV-2. In a multivariate model, HIV infection was associated with HSV-2 infection (adjusted odds ratio [AOR] = 3.5, 95% confidence interval 1.1-11.7) and non-HSV-related sexually transmitted infection diagnosis in the previous year (AOR = 2.6, 1.1-6.2). Effective approaches to HIV risk reduction for individuals with HSV-2 remain uncertain, and these are urgently needed in high-risk communities where multiple social, behavioural and biological factors that facilitate HIV infection coexist.

Effect of acute hypercapnia on diaphragmatic and limb muscle contractility

The purpose of this study was to determine whether acute hypercapnia depresses limb muscle and diaphragmatic contractility. Twelve subjects breathed 8% CO2 for 20 min on two separate occasions. On one occasion, twitch transdiaphragmatic pressure (Pdi) was obtained during both cervical magnetic and transcutaneous stimulation before and 2, 10, and 30 min after CO2 breathing. In addition, twitch Pdi was obtained during CO2 breathing in five subjects using cervical magnetic stimulation. On the other occasion, adductor pollicis twitch force was measured during transcutaneous supramaximal ulnar nerve stimulation and arterialized venous blood gas determinations were obtained before, during, and after CO2 breathing. Twitch Pdi was not significantly different from baseline at any time after CO2 breathing. Similarly, twitch Pdi did not significantly change from the beginning to the end of the period of CO2 breathing. In contrast, adductor pollicis twitch force was significantly less than baseline 2 min after CO2 breathing (p < 0.01). Furthermore, during CO2 breathing, adductor pollicis twitch force fell significantly, reaching statistical significance at 8 min, decreasing still further by 13 min, and then plateauing. During the final 2 min of CO2 breathing, adductor pollicis twitch force averaged 86.5 +/- 2.7% of the baseline value (p < 0.0007). During CO2 breathing, Pco2 rose to 60.1 +/- 0.5 mm Hg, whereas pH fell to 7.27 +/- 0.004 units. Breathing 8% CO2 elicited a moderate hyperpnea, and minute ventilation during the final minute of CO2 breathing averaged 54.74 +/- 4.90 L/min. To ensure that this hyperpnea did not augment diaphragmatic activity enough to potentiate the twitch, five subjects voluntarily mimicked their CO2 hyperpnea on a separate occasion. Twitch Pdi was not significantly different from baseline at any time after voluntary mimicking. To ensure that changes in diaphragmatic contractility were not missed by our twitch measurements, Pdi was measured during bilateral transcutaneous phrenic nerve stimulation at 10 Hz in four subjects. Again, Pdi during 10 Hz stimulation was not significantly different from baseline at any time after CO2 breathing. In conclusion, (1) acute moderate hypercapnia mildly depresses limb muscle contractility, and (2) acute moderate hypercapnia did not produce significant changes in diaphragmatic contractility.

Heated lymphocytes express HLA-DR antigens despite their inability to stimulate in MLC

We have utilized serological techniques and mixed lymphocyte culture (MLC) reactions to examine HLA-DR and HLA-D expression by heated (45 degrees C for 1 h) lymphocytes in order to study the functional relationship of these antigens. Heated lymphocytes do not stimulate proliferation of allogeneic lymphocytes in MLC, yet they express HLA-DR antigens. The fraction of peripheral blood lymphocytes (PBL) expressing DR is not altered by heating, nor is the staining intensity altered as detected by fluorescence microscopy. Alloantisera to "B cell alloantigens" recognize HLA-DR determinants on heated cells without any detectable change in either specificity or quantitative cytotoxic effects. Flow cytometry with monoclonal antibody demonstrates only minimal decrease in HLA-DR expression after heating. Thus stimulation in MLC requires more of the stimulating cell than the mere expression of HLA-DR.

HLA identical leukemia cells and T cell growth factor activate cytotoxic T cell recognition of minor locus histocompatibility antigens in vitro

Lymphocytes from a healthy HLA-identical bone marrow transplant donor were tested for their ability to destroy her brother's acute myelogenous leukemia blasts in vitro. Primary mixed lymphocyte culture (MLC) and cell-mediated lysis (CML) responses between the patient's remission (pretransplant) and donor's lymphocytes were negative. Stimulation of donor lymphocytes for 7 d in vitro with irradiated leukemia cells, leukemia cells plus allogeneic irradiated lymphocytes, or a pool of irradiated lymphocytes from 10 donors, did not activate any cytotoxic cells able to destroy the HLA identical leukemic blasts. Further culturing for 7 additional d in T cell growth factor (TCGF) generated lymphocytes that induced effective cytotoxicity against the leukemic blasts, but not against autologous lymphocytes. Effective killing against the leukemia was observed only in cultures initially stimulated with the irradiated leukemia cells. These cytotoxic cells were maintained in TCGF and mediated persistent killing against the leukemic target cells. They were also able to destroy lymphocytes from the patient's mother and father, but not from an unrelated cell donor. This suggested specific recognition of non-HLA antigens inherited by the patient, that were foreign to the HLA identical bone marrow donor. These lymphocytes were cloned by a limiting dilution technique and one clone maintained cytotoxicity to the AML blasts and the father's lymphocytes, but not lymphocytes from the mother or an HLA-identical donor. This cytotoxicity was inhibited by a monoclonal anti-HLA antibody. Thus, in vitro sensitization of this sibling's lymphocytes with AML blasts followed by TCGF expansion, and cloning, enabled the detection of HLA-restricted cytotoxic cells that recognize minor locus histocompatibility antigens. This immune recognition may be relevant to the "graft vs. leukemia" effect that has been observed in leukemic animals and patients following histocompatible hematopoietic transplants.