Right lobe living donor liver transplantation: a review

The continuing shortage of organs for adult transplant recipients has generated enthusiasm for adult-to-adult living donor liver transplantation (LDLT). The major concern has been the ability to resect a graft of adequate size without subjecting the donor to undue risk. The right hepatic lobe is generally large enough for adult recipients, but because of the real and perceived risks of right lobe (RL) resection, surgeons have been hesitant to offer this option to their patients. The first series of RL resections that included a significant number of patients was reported in 1999, and the results were encouraging. Only minor complications occurred in donors, and the recipients fared quite well. Enthusiasm for these donor resections is growing, and more centers are beginning to perform them. There is a good deal of global experience with pediatric LDLT but little with adults, and there are unique considerations in this population. This review examines donor selection criteria for adult recipients, highlights technical points critical for good outcome, and examines the early results and complications in both donors and recipients. If the preliminary results continue to be reproduced, RL LDLT could have significant impact on the worsening organ shortage.

Right lobe living donor liver transplantation: a review

The continuing shortage of organs for adult transplant recipients has generated enthusiasm for adult-to-adult living donor liver transplantation (LDLT). The major concern has been the ability to resect a graft of adequate size without subjecting the donor to undue risk. The right hepatic lobe is generally large enough for adult recipients, but because of the real and perceived risks of right lobe (RL) resection, surgeons have been hesitant to offer this option to their patients. The first series of RL resections that included a significant number of patients was reported in 1999, and the results were encouraging. Only minor complications occurred in donors, and the recipients fared quite well. Enthusiasm for these donor resections is growing, and more centers are beginning to perform them. There is a good deal of global experience with pediatric LDLT but little with adults, and there are unique considerations in this population. This review examines donor selection criteria for adult recipients, highlights technical points critical for good outcome, and examines the early results and complications in both donors and recipients. If the preliminary results continue to be reproduced, RL LDLT could have significant impact on the worsening organ shortage.

Right lobe living donor liver transplantation

BACKGROUND

The shortage of livers for transplantation has prompted transplant centers to seek alternatives to conventional cadaveric liver transplantation. Left lateral segmentectomy from living donors has proven to be a safe operation for the donor with excellent results in the pediatric population. Left lobectomy, conceived to supply more tissue, still provides insufficient liver mass for an average size adult patient. Right lobectomy could supply a graft of adequate size.

METHODS

Donors were considered only after recipients were listed according to United Network for Organ Sharing (UNOS) criteria. Donor evaluation included liver biopsy, magnetic resonance imaging, and celiac and mesenteric angiography. The donor operation consisted of a right lobectomy uniformly performed throughout the series as described herein.

RESULTS

Twenty-five right lobe living donor liver transplants were performed between adults, with no significant complications in donors. Recipient and graft survival was 88%, with three recipient deaths secondary to uncontrolled sepsis in patients at high risk for liver transplant; all three had functioning grafts.

CONCLUSIONS

Right lobe living donor liver transplantation poses challenges that require a meticulous surgical technique to minimize morbidity in the recipient. Right lobectomies for living donation can be performed safely with minimal risk to both donor and recipient although providing adequate liver mass for an average size adult patient.

[Effect of the diet on the nutritional status of ballerinas: immunologic markers]

Athletes have special nutritional needs that will vary with sex, age, body composition and most importantly by the type, intensity, frequency and duration of the physical exercise. However the diet of certain groups of athletes such as ballet dancers is inadequate due to overly restrictive habits as a consequence of their obsession with losing or maintaining a low body weight that reflects an aesthetic preference for thinness. Physical exercise implies energy expenditure and thus, an increase in the energy intake is required to avoid possible situations of malnutrition. Both a negative energy balance and physical exertion have been shown to induce immunological changes which have been implicated as a possible explanation for increased susceptibility to illness and infections.

OBJECTIVE

To find out the influence of a restricted energy intake on the immune system of 14 ballet dancers (20-25 h/w) in comparison with a control sedentary group (n = 23) by evaluating dietetic, anthropometric and some immunological parameters.

RESULTS

Ballet dancers consumed a hypocaloric diet (mean: 1555 kcal), the energy intake being significantly lower than in the control group. None of both groups showed a similar calorie profile to the recommended intake for Spanish population, especially fat percentage was higher than it should. Regarding weight, ideal body weight and BMI values, no significant differences were shown between both groups. However, all the skinfolds thickness and the sum of skinfolds were significantly lower in ballet dancers than in controls. Leukocytes, lymphocytes and all lymphocyte subset counts were lower in ballet dancers in comparison with controls.

CONCLUSIONS

In view of these results, ballet dancers may suffer from an impaired nutritional status, determined by a depletion of anthropometric and immunological parameters. The nutritional requirements for this population should be increased in order to compensate their high-energy expenditure, avoid a negative energy balance and lessen the nutritional damage.

Central venous catheter exchange by guidewire for treatment of catheter-related bacteraemia in patients undergoing BMT or intensive chemotherapy

Current guidelines for the treatment of catheter-related bacteraemia (CRB) advise against central venous catheter (CVC) exchange because of the potential risk of prolonging infection. However, there are no consistent data proving this recommendation. We evaluated prospectively the usefulness of CVC exchange by guidewire for the treatment of CRB in patients undergoing BMT or intensive chemotherapy. CVC exchange was considered when fever and positive blood cultures persisted after 2 days of adequate antimicrobial therapy and no potential source of bacteraemia other than CVC could be identified. The guidewire exchange was preceded and followed by a slow infusion of adequate antimicrobial therapy. Bacteraemia was confirmed as catheter-related by demonstrating concordance between isolates from the tip and blood cultures by pulsed-field electrophoresis of genomic DNA. This procedure was performed in 19 episodes of bacteraemia during a 1-year period. Fourteen episodes (74%) were catheter-related and 71% of these were due to coagulase-negative staphylococci. Guidewire replacement was accomplished uneventfully 4 days after development of sepsis (range 3-6). In all cases, clinical signs of sepsis disappeared in less than 24 h after replacement. Definitive catheter withdrawal was carried out a median of 16 days (range 3-42) after guidewire exchange; in all cases, the tip culture was negative. We conclude that CVC replacement by guidewire under adequate antimicrobial therapy may be a reasonable option for the treatment of CRB when antimicrobial therapy alone has been unsuccessful.

A prospective randomized trial of mycophenolate mofetil with neoral or tacrolimus after orthotopic liver transplantation

BACKGROUND

The success of liver transplantation in this decade has become the stimulus to extend the donor and recipient pool. Reducing early posttransplant morbidity to maintain our success, as we expand our frontiers, has led us to focus on balanced testing of multidrug immunosuppression regimens.

METHODS

A prospective trial in orthotopic liver transplantation using Mycophenolate Mofetil and an identical steroid taper with randomization of patients to Neoral (N) or Tacrolimus (FK) is the basis of this report. This was an intent-to-treat study designed to compare the 6-month primary endpoints of rejection and infection and to compare the 6-month secondary endpoints of liver function, renal function, bone marrow function, hypertension, and serum cholesterol levels.

RESULTS

Ninety-seven patients completed the 6-month follow-up period (N=49, FK=48). The actual 6-month patient and graft survival rates were 98% and 94%, respectively. There was no difference in the number of patients with rejection episodes (N=11, FK=8) (P=0.61). There were 24 infections (3 cytomegalovirus) in the FK group and 30 infections (9 cytomegalovirus) in the N group. The cholesterol levels at 6 months were not significantly different (P=0.07) between the groups. The other secondary 6-month endpoints were not significantly different, except total bilirubin, which was lower in the FK arm (P=0.02).

CONCLUSIONS

The use of Mycophenolate Mofetil with N or FK and an identical steroid taper after orthotopic liver transplantation is associated with excellent graft and patient survival, and at 6 months, only 191% of the patients experienced rejection, with a 48% overall infection rate.

Intraocular pressure as a risk factor for visual field loss in pseudoexfoliative and in primary open-angle glaucoma

OBJECTIVE

To analyze the relationship between intraocular pressure (IOP) and visual field loss in patients with primary open-angle glaucoma (POAG) and in those with pseudoexfoliative glaucoma (PEXG).

DESIGN

A cross-sectional, observational study.

PARTICIPANTS

Thirty-one patients with PEXG and 31 patients with POAG that was newly diagnosed were included in this study.

MAIN OUTCOME MEASURES

The authors recorded the untreated IOP and the amount of the visual field loss, at presentation, in both study groups.

RESULTS

The authors found a significant relationship between IOP and visual field mean deviation (MD) index (P = 0.0001, r = 0.68) in PEXG but not in POAG eyes (P = 0.7).

CONCLUSION

The authors found that untreated IOP levels can explain the amount of visual field loss, as measured by the MD index, much better in patients with PEXG than in comparable patients with POAG. Thus, vulnerability of the optic nerve head to increased IOP appears to be different in these two diagnostic categories.

Viscoelastic-injecting cystotome

This continuous curvilinear capsulorhexis (CCC) technique is for use in complicated surgical cases such as when the anterior chamber is shallow, the red reflex is not good, or eye movements are present. This technique is easier and safer in such cases because it uses a cystotome connected to a viscoelastic syringe. First, the anterior chamber is filled with viscoelastic material using a conventional cannula. The cannula is replaced with a bent needle (or cystotome), and the CCC is performed in the usual way. This instrument allows the surgeon to inject small amounts of viscoelastic material exactly where and when it is needed. The anterior chamber remains deep while the CCC is performed, and the anterior capsule tear is done in a more controlled fashion.

Immunodeficiency associated with anorexia nervosa is secondary and improves after refeeding

Several studies have addressed the question of starvation effects on immune function by means of changes in lymphocyte subsets, cytokine induction or lymphocyte activation. Anorexia nervosa (AN) patients are severely malnourished and contradictory results have been obtained regarding the accompanying immunodeficiency, including its assignation as a part of the primary nervous disorder. In the present work, an extensive immunological function examination was carried out on 40 AN patients who were compared with a control group of 14 healthy girls. The AN patients were also classified according to their nutritional status (by the Body Mass Index: BMI), this being critical for a better understanding of these secondary immunodeficiency bases. Moreover, another immune system study was performed on five patients after refeeding. Lymphocyte subsets and function, cytokine induction and peripheral blood concentrations, and innate as well as humoral immunity were evaluated. Deregulation in the cytokine network, owing to the interaction of the central nervous (CNS) and immune systems, seems to be the initial immune alteration in AN immunodeficiency but it has not been disproved that the immunodeficiency is a direct consequence of the original psychiatric perturbation. Spontaneous high levels of circulating interleukin-1beta (IL-1beta) and tumour necrosis factor-alpha (TNF-alpha) have been observed; this is probably one of the causes of the anomalies found in the T-cell subpopulations (mainly the naive CD4+CD45RA+ reduction and the cytotoxic CD8+ increase) and T-cell activation status (mainly the down-regulation of the CD2 and CD69 activation pathways). This finally leads to an impairment, not only in T-cell function but also in T-cell to B-cell co-operation. The AN specificity of these results is confirmed by the fact that these immune alterations improve after refeeding and when nutritional status becomes less critical, which also suggests that AN immunodeficiency is indeed secondary to malnutrition.

The immune system in eating disorders: an overview

Eating disorders, such as anorexia nervosa and bulimia nervosa, are becoming more and more common in our society. Although they are psychiatric illnesses, there are many factors involved, including abnormal food behavior. Nutrients play an important role in the development and functionality of immunocompetent cells. An impaired immunocompetence has been shown to be an important causal factor in the increased susceptibility of malnourished individuals to infectious disease. Therefore, studies on the immune system are of great interest when assessing the extent to which the nutritional status of these patients could be affected. However, the literature in this field is controversial, and the mechanisms are not yet completely defined, although some hypotheses try to clarify the disturbances caused in the organism under these bizarre circumstances. In spite of the fact that the immune system is altered by distorted food behaviors, such as in eating disorders, the awareness of characteristics of other systems involved, and therefore altered, by these pathologies would be very helpful for understanding the mechanisms triggered in these syndromes. In fact, the interactions among the immune and other systems in eating disorders are beginning to be studied. Finally, the main goals are to limit the evolution of these illnesses through early diagnosis, and to devise a long-lasting, definitive cure for these patients through appropriate therapy.

Evaluation of nutritional status by immunologic assessment in bulimia nervosa: influence of body mass index and vomiting episodes

The nutritional status of 21 patients suffering from bulimia nervosa was evaluated by anthropometric and immunologic indexes in comparison with a control group (n = 15). In addition, the influence of body mass index (BMI; in kg/m2) values and vomiting episodes on the nutritional status of bulimic patients was assessed. Anthropometry showed no signs of malnutrition in either group, except for those patients with low weights (BMI < 19). Bulimic patients had lower lymphocyte counts than did control subjects, except for those without vomiting (NVBN). All T lymphocyte subsets tested as well as CD57 cells were lower (22% and 55%, respectively) in bulimic patients than in control subjects, but the CD19 cell subset remained unmodified. The low-weight bulimic group (LWBN) had lower CD4 cell counts than did the normal-weight (BMI > 19) bulimic group. The NVBN group had lymphocyte subpopulations similar to those in the control group, except for CD57, which was lower. The bulimic patients with vomiting had the lowest cell subset values. These results suggest a depleted nutritional status in all bulimic patients studied, even those with normal weights. The LWBN group had the most depleted nutritional status and the NVBN group was least affected at a subclinical level. CD57 can be considered a good marker of nutritional status in this syndrome because it was the only subpopulation altered in all groups.

Effects of human immunodeficiency virus infection and detoxification time on anthropometric measurements and dietary intake of male drug addicts

Anthropometric measurements and dietary intakes of male drug addicts (n = 62), infected (n = 23) or not infected (n = 39) with human immunodeficiency virus (HIV), who underwent two phases of detoxification (P1:15 d to 1 mo and P2: 5-6 mo) were assessed. Body weight, weight gain during detoxification, height, body mass index, and ideal body weight were measured. A prospective food-record questionnaire was compiled and energy and nutrient contents of ingested food were determined. Food intakes were compared with dietary recommendations for the Spanish population. At the time of the study, all patients had substantial weight gains, mostly in P1. Nutrient consumption was lower in P2 (energy, protein, and lipids) and in groups not infected with HIV. In P2, lipid intake was higher in the HIV-positive than in the HIV-negative group (P < 0.05, Student's t test). Moreover, an interactive effect of HIV by phase was shown for lipid intake (P = 0.04, two-way analysis of variance). Magnesium, folate, and vitamin E intakes were lower than recommended in nearly all patients. Energy, zinc, riboflavin, and vitamin B-6 intakes were lower than recommended or were borderline. HIV infection did not have a negative effect on anthropometric measurements or on nutrient intakes. The anthropometric assessment may suggest an adequate recovery of the indexes measured in all patients, which principally took place during P1. Measurement of nutrient intakes showed certain imbalances and deficits that should be corrected.

Human immunodeficiency virus infection and nutritional status in female drug addicts undergoing detoxification: anthropometric and immunologic assessments

To clarify the interrelations among drug abuse, malnutrition, and immunosuppression, the effects of human immunodeficiency virus (HIV) infection on the nutritional status of 17 noninfected and 19 HIV-infected asymptomatic female drug addicts undergoing detoxification were evaluated by measuring anthropometric and immunologic indexes. Anthropometric measurements were normal in both groups as a result of weight gain (approximately 10 kg) in every patient after the detoxification period. Leukocyte and lymphocyte values and CD2 lymphocyte subset counts were also similar in both groups. CD4 counts (P = 0.04) and the ratio of CD4 to CD8 cells (P = 0.6 x 10(-4)) were lower whereas CD8 counts (P = 0.003) were higher in the HIV-infected than in the noninfected group. Responses to a delayed-hypersensitivity skin test were below normal in both groups but significantly more so in the HIV-positive group (P = 0.05). CD19 counts were lower (P = 0.02) and values for serum immunoglobulins G and M were higher (51% and 37%, respectively) in the HIV-infected females than in the noninfected women. These results may suggest that despite anthropometric recovery, the HIV-infected women had depleted immune function, resulting not only from HIV infection but also from the subclinical malnutrition triggered by previous drug addiction.

Interactions between nutrition and immunity in anorexia nervosa: a 1-y follow-up study

Nutritional status and immunocompetence were evaluated in 15 patients suffering from anorexia nervosa in comparison with a control group (n = 15). After 1 y, data from six phases of the study were evaluated: immediately after admittance to the hospital (AN1), after 1 mo (AN2), after 2 mo (AN3), after 3 mo (AN4), after 6 mo (AN5), and after 1 y, (AN6). Patients recovered weight from AN4 until AN6 although, according to body mass index values, all patients had low weights during the 1-y follow-up. Likewise, leukocyte and lymphocyte values were borderline and lower in patients in all phases tested than in control subjects. All lymphocyte subpopulations were lower in AN1 and AN2 patients (inpatients) than in control subjects, except for CD19 cells, which remained unmodified. There seemed to be a recovery of lymphocyte subsets after hospitalization in AN3 and AN4 patients (outpatients), except for CD57, which remained below control values. However, there was a global decrease of the lymphocyte subsets in AN5 and AN6. Ratios of CD4 to CD8 cells were not altered but the ratio of CD2 to CD19 cells was lower in all phases except AN6. Moreover, cell-mediated immune function was impaired and none of the patients showed normal responses. Thus, despite the slight weight increase found in AN4, AN5, and AN6 and the apparent cell subset recovery after hospitalization, these results suggest a greatly depleted nutritional status that remained during the whole year in all patients.

Immunocompetence in relation to a heat-processed diet (Maillard reaction) in weanling rats

Diets containing unheated casein (CD; control) or a casein-glucose mixture (CGD) previously heated at 140 degrees for 2 h were fed to two groups of young rats for 21 d. Differences in body weight, feed consumption, thymus, and spleen growth, protein metabolism and in vivo immune response were then determined. For this last experiment, animals were inoculated with sheep erythrocytes (SRBC) on day 15 to provide an immunological challenge. No changes were seen in body weight, feed consumption or feed conversion ratios. Neither were significant differences found in spleen weight, protein content, DNA content, DNase (EC 3.1.4.6) activity or lymphocyte count, suggesting that spleen cell growth remained similar in all the animals studied. The CGD induced marked increases in thymus DNA content whilst the protein:DNA ratio became lower. Spleen RNA content was similar in all rats, but thymus RNA content was 29% lower in the CGD group, although this difference did not reach statistical significance. This fact might be a consequence of the low RNase (EC 2.7.7.16) activity and RNase:RNA ratios in the thymus glands of CGD-fed animals. Further, the number of splenic plasma cells secreting anti-SRBC antibodies (direct plaque-forming cells) was significantly decreased in the same group. It might be concluded that both diets are adequate for rat growth and that the differences observed in the thymus of CGD-fed rats may be directed towards preserving tissue function. Nevertheless, the CGD did cause immunological disturbances affecting the humoral immune response.

Crosslink Reaction Mechanisms of Diene Rubber with Dicumyl Peroxide

The scope of this paper is to review peroxide curing of diene elastomers. At high dicumyl peroxide loading and high curing temperature, changes in the crosslinking mechanisms were observed. Both Abstraction of allylic hydrogen and addition to the double bond can act as mechanisms of crosslinking. IR spectroscopy reveals a significant decrease in double bonds, and a new relaxation at temperatures above the Tg of the elastomers is present.

A New Carbon Black-Rubber Coupling Agent to Improve Wet Grip and Rolling Resistance of Tires

The compound p-aminobenzenesulfonyl azide was developed as a new type of carbon black to rubber coupling agent. Its addition to rubber compounds increases resilience and moduli while reducing abrasion loss. The behavior of this coupling agent is confirmed by the dynamic mechanical response of the vulcanizates—the rubber Tg is shifted to higher temperatures. Rubber compositions containing this coupling agent may be used in tire treads to reduce rolling resistance and improve wet skid resistance. These attributes were estimated from dynamic property measurements.

Mutation in the gyrA gene of quinolone-resistant clinical isolates of Acinetobacter baumannii

The gyrA gene mutations associated with quinolone resistance were determined in 21 epidemiologically unrelated clinical isolates of Acinetobacter baumannii. Our studies highlight the conserved sequences in the quinolone resistance-determining region of the gyrA gene from A. baumannii and other bacteria. All 15 isolates for which the MIC of ciprofloxacin is > or = 4 micrograms/ml showed a change at Ser-83 to Leu. Six strains for which the MIC of ciprofloxacin is 1 microgram/ml did not show any change at Ser-83, although a strain for which the MIC of ciprofloxacin is 1 microgram/ml exhibited a change at Gly-81 to Val. Although it is possible that mutations in other locations of the gyrA gene, the gyrB gene, or in other genes may also contribute to the modulation of the MIC level, our results suggest that a gyrA mutation at Ser-83 is associated with quinolone resistance in A. baumannii.

A comparative study of ribotyping and arbitrarily primed polymerase chain reaction for investigation of hospital outbreaks of Acinetobacter baumannii infection

Arbitrarily primed polymerase chain reaction (AP-PCR) and ribotyping were compared in an investigation of an outbreak of Acinetobacter baumannii infections. Twenty-five clinical isolates shown previously by other criteria to belong to two different groups, and nine randomly selected A. baumannii clinical isolates from other hospitals were investigated. Among the strains analysed, nine different EcoRI rRNA gene restriction pattern fingerprints were observed. While similarity was detected between strains of the same group, these fingerprints differed clearly between the two A. baumannii groups defined in the outbreak. Two of the nine strains selected randomly had the same ribotype as those strains involved in the outbreak, whereas the remaining seven strains each had a different ribotype. When the strains were tested by AP-PCR with 0.25, 0.5 or 1 microM of M13 forward primer, 10 different profiles were obtained. However, 11 profiles were observed if two different primer concentrations (0.25 and 1 microM) were used. It was concluded that ribotyping and AP-PCR exhibited a similar discriminatory power, although AP-PCR had the additional advantages of speed and simplicity.