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.

Obesity and immune function relationships

The immunological processes involved in the collaborative defence of organisms are affected by nutritional status. Thus, a positive chronic imbalance between energy intake and expenditure leads to situations of obesity, which may influence unspecific and specific immune responses mediated by humoral and cell mediated mechanisms. Furthermore, several lines of evidence have supported a link between adipose tissue and immunocompetent cells. This interaction is illustrated in obesity, where excess adiposity and impaired immune function have been described in both humans and genetically obese rodents. However, limited and often controversial information exist comparing immunity in obese and non-obese subjects as well as about the cellular and molecular mechanisms implicated. In general terms, clinical and epidemiological data support the evidence that the incidence and severity of specific types of infectious illnesses are higher in obese persons as compared to lean individuals together with the occurrence of poor antibody responses to antigens in overweight subjects. Leptin might play a key role in linking nutritional status with T-cell function. The complexities and heterogeneity of the host defences concerning the immune response in different nutritional circumstances affecting the energy balance require an integral study of the immunocompetent cells, their subsets and products as well as specific and unspecific inducer/regulator systems. In this context, more research is needed to clarify the clinical implications of the alterations induced by obesity on the immune function.

Design and implementation of the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study

OBJECTIVE

To provide an overview of the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS) design, with particular attention to its quality control procedures. Other important methodological aspects are described in detail throughout this supplement.

DESIGN

Description of the HELENA-CSS sampling and recruitment approaches, standardization and harmonization processes, data collection and analysis strategies and quality control activities.

RESULTS

The HELENA-CSS is a multi-centre collaborative study conducted in European adolescents located in urban settings. The data management systems, quality assurance monitoring activities, standardized manuals of operating procedures and training and study management are addressed in this paper. Various quality controls to ensure collection of valid and reliable data will be discussed in this supplement, as well as quantitative estimates of measurement error.

CONCLUSION

The great advantage of the HELENA-CSS is the strict standardization of the fieldwork and the blood analyses, which precludes to a great extent the kind of immeasurable confounding bias that often interferes when comparing results from isolated studies.

Liver regeneration and function in donor and recipient after right lobe adult to adult living donor liver transplantation

BACKGROUND

Regeneration of the liver to a predetermined size after resection or transplantation is a well described phenomenon, but the time course over which these events occur has not been well defined. It is not clear how initial liver mass, reperfusion, immunosuppression, or steatosis influence this process.

METHODS

Liver regeneration was assessed prospectively by volumetric magnetic resonance imaging (MRI) in living right lobe liver donors and the recipients of these grafts. Imaging was performed at regular intervals through 60 days after resection/transplantation, and liver mass was determined. Liver function tests and synthetic function were monitored throughout the study period in donors and recipients of these grafts as well as recipients of cadaveric grafts.

RESULTS

MRI consistently overestimated liver mass by a mean of 45 g (+/-65) (range 10-123). Donor liver mass increased by 101%, 110%, 115%, and 144% at 7, 14, 30, and 60 days after resection, respectively. Recipient liver mass increased by 87,101, 119, and 99% at 7, 14, 30, and 60 days after transplantation, respectively. Steatosis did not influence the degree of regeneration or graft function, nor was there a functional difference between grafts of >1% graft to recipient body weight ratio or <1%.

CONCLUSIONS

MRI accurately determines right lobe mass. Most liver regeneration occurs in the 1st week after resection or transplantation, and the time course does not differ significantly in donors or recipients. The mass of the graft or remnant segment affects the duration of the regeneration process, with a smaller initial liver mass prolonging the course. Steatosis of <30% had no bearing on liver function or regeneration and, therefore, should not be an absolute criterion for exclusion of donors. A calculated graft to recipient body weight ratio of 0.8% is adequate for right lobe living donor liver transplantation.

Selection and outcome of living donors for adult to adult right lobe transplantation

BACKGROUND

The shortage of cadaveric livers has sparked an interest in adult-to-adult living donor transplantation. Right lobe donor hepatectomy is frequently required to obtain a graft of adequate size for adult recipients. Careful donor selection is necessary to minimize complications and assure a functional graft.

METHODS

A four-step evaluation protocol was used for donor selection and satisfactory results of all tests in each step were required before proceeding to the next. Donors were selected based on a battery of laboratory studies chosen to exclude unrecognized infection, liver disease, metabolic disorders, and conditions representing undue surgical risk. Imaging studies included ultrasonography, angiography, magnetic resonance imaging, and intraoperative cholangiography and ultrasonography. The information obtained from liver biopsy was used to correct the estimated graft mass for the degree of steatosis.

RESULTS

From March 1998 to August 1999, 126 candidates were evaluated for living donation. A total of 35 underwent donor right lobectomy with no significant complications. Forty percent of all donors that came to surgery were genetically unrelated to the recipient. A total of 69% of those evaluated were excluded. ABO incompatibility was the primary reason for exclusion after the first step (71%) and the presence of steatosis yielding an inadequate estimated graft mass after the second step (20%).

CONCLUSIONS

Donor selection limits the application of living donor liver transplantation in the adult population. Unrelated individuals increase the size of the donor pool. Right lobe hepatectomy can be performed safely in healthy adult liver donors. Preoperative liver biopsy is an essential part of the evaluation protocol, particularly when the estimated graft mass is marginal.

The HLA-DQ2 genotype selects for early intestinal microbiota composition in infants at high risk of developing coeliac disease

OBJECTIVE

Intestinal dysbiosis has been associated with coeliac disease (CD), but whether the alterations are cause or consequence of the disease is unknown. This study investigated whether the human leukocyte antigen (HLA)-DQ2 genotype is an independent factor influencing the early gut microbiota composition of healthy infants at family risk of CD.

DESIGN

As part of a larger prospective study, a subset (n=22) of exclusively breastfed and vaginally delivered infants with either high genetic risk (HLA-DQ2 carriers) or low genetic risk (non-HLA-DQ2/8 carriers) of developing CD were selected from a cohort of healthy infants with at least one first-degree relative with CD. Infant faecal microbiota was analysed by 16S rRNA gene pyrosequencing and real time quantitative PCR.

RESULTS

Infants with a high genetic risk had significantly higher proportions of Firmicutes and Proteobacteria and lower proportions of Actinobacteria compared with low-risk infants. At genus level, high-risk infants had significantly less Bifidobacterium and unclassified Bifidobacteriaceae proportions and more Corynebacterium, Gemella, Clostridium sensu stricto, unclassified Clostridiaceae, unclassified Enterobacteriaceae and Raoultella proportions. Quantitative real time PCR also revealed lower numbers of Bifidobacterium species in infants with high genetic risk than in those with low genetic risk. In high-risk infants negative correlations were identified between Bifidobacterium species and several genera of Proteobacteria (Escherichia/Shigella) and Firmicutes (Clostridium).

CONCLUSIONS

The genotype of infants at family risk of developing CD, carrying the HLA-DQ2 haplotypes, influences the early gut microbiota composition. This finding suggests that a specific disease-biased host genotype may also select for the first gut colonisers and could contribute to determining disease risk.

Single-center analysis of the first 40 adult-to-adult living donor liver transplants using the right lobe

The first adult-to-adult living donor liver transplant using the right hepatic lobe in the United States was performed only 2 years ago. Although initial reports were encouraging, continuous review of the results and appropriate modifications in patient management will be necessary to minimize donor risk and optimize recipient outcome. The results of 40 such transplantations were analyzed and are summarized. Recipients were listed for transplantation according to the usual criteria. Living donors were not considered for United Network for Organ Sharing status IIA patients after the initial 22 patients. Donor evaluation followed a rigid protocol. A graft-to-recipient body weight ratio of at least 0.8% was the minimum required throughout most of the study. The surgical procedures were similar, except the plane of transection was modified to better accommodate donor biliary anatomy, and uniform stenting of bile ducts was practiced after the first 10 transplants. Immunosuppression consisted of tacrolimus, mycophenolate mofetil, and a prednisone taper. The target tacrolimus level was decreased and mycophenolate was withdrawn more rapidly in the second half of the study because of the absence of acute cellular rejection. Donor morbidity has been limited to minor complications, and transplant recipient biliary complications decreased from 35% to 0%. Acute cellular rejection has not been observed despite less aggressive immunosuppression, and septic complications decreased dramatically. There have been no recipient deaths since these changes were instituted. Right lobectomy can be performed safely in the donor population. Recipient biliary complications can be minimized with stenting. Less aggressive immunosuppression is well tolerated and minimizes septic complications and attributable mortality.

Assessing, understanding and modifying nutritional status, eating habits and physical activity in European adolescents: The HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study

Objectives

To identify the main knowledge gaps and to propose research lines that will be developed within the European Union-funded ‘Healthy Lifestyle in Europe by Nutrition in Adolescence’ (HELENA) project, concerning the nutritional status, physical fitness and physical activity of adolescents in Europe.

Design

Review of the currently existing literature.

Results

The main gaps identified were: lack of harmonised and comparable data on food intake; lack of understanding regarding the role of eating attitudes, food choices and food preferences; lack of harmonised and comparable data on levels and patterns of physical activity and physical fitness; lack of comparable data about obesity prevalence and body composition; lack of comparable data about micronutrient and immunological status; and lack of effective intervention methodologies for healthier lifestyles.

Conclusions

The HELENA Study Group should develop, test and describe harmonised and state-of-the-art methods to assess the nutritional status and lifestyle of adolescents across Europe; develop and evaluate an intervention on eating habits and physical activity; and develop and test new healthy food products attractive for European adolescents.

Surgical management of anatomical variations of the right lobe in living donor liver transplantation

OBJECTIVE

To review the anatomical variations of the right lobe encountered in 40 living liver donors, describe the surgical management of these variations, and summarize the results of these procedures.

SUMMARY BACKGROUND DATA

Anatomical variability is the rule rather than the exception in liver and biliary surgery. To make effective use of liver segments from living donors for transplantation, surgical techniques must be adapted to the anomalies.

METHODS

Donor evaluation included celiac and mesenteric angiography with portal phase, magnetic resonance angiography, and intraoperative ultrasonography and cholangiography. Arterial anastomoses were generally between the donor right hepatic artery and the recipient main hepatic artery. Jump-grafts were constructed for recipients with hepatic artery thrombosis, and double donor arteries were joined to the bifurcation of the recipient hepatic artery. The branches of a trifurcated donor portal vein were isolated during the parenchymal transection, joined in a common cuff, and anastomosed to the recipient main portal vein. Significant accessory hepatic veins were preserved, brought together in a common cuff if multiple, and anastomosed to the recipient cava. The bile ducts were individually drained through a Roux-en-Y limb, and stents were placed in most patients.

RESULTS

Forty right lobe liver transplants were performed between adults. No donor was excluded because of prohibitive anatomy. Seven recipients had a prior transplant and five had a transjugular intrahepatic portosystemic shunt (TIPS). Arterial anomalies were noted in six donors and portal anomalies in four. Arterial jump-grafts were required in three. Sixteen had at least one significant accessory hepatic vein, and one had a double right hepatic vein. There were no vascular complications. Multiple bile ducts were found in 27 donors. Biliary complications occurred in 33% of patients without stents and 4% with stents.

CONCLUSIONS

Anatomical variations of the right lobe can be accommodated without donor complications or complex reconstruction. Previous transplantation and TIPS do not significantly complicate right lobe transplantation. Microvascular arterial anastomosis is not necessary, and vascular complications should be infrequent. Biliary complications can be minimized with stenting.

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.

Possible roles of magnesium on the immune system

During the last few years, magnesium (Mg) has been subject of research due to its functionality in the organism. It is one of the most important micronutrients, and therefore its role in biological systems has been extensively investigated. Particularly, Mg has a strong relation with the immune system, in both nonspecific and specific immune response, also known as innate and acquired immune response. The aim of this paper is to review the state of the art about the interactions between Mg and the immune system. We discuss the link between dietary Mg and inflammation, apoptosis and alterations in number and function of innate immune cell populations, described in animal models. Furthermore, the immune system can be compromised in human populations under certain circumstances, including athletes and elderly people. The importance of a balanced Mg homeostasis and its interaction with the immune system in these groups has also been reviewed. Although emerging data support the relevant role of Mg in the immune response, further research is needed; and special efforts should be made to establish the most adequate dose in nutritional supplements to reach beneficial effects on health.

Survival of liver transplant patients coinfected with HIV and HCV is adversely impacted by recurrent hepatitis C

Although liver transplantation (LTx) in HIV-positive patients receiving highly active antiretroviral therapy (HAART) has been successful, some have reported poorer outcomes in patients coinfected with hepatitis C virus (HCV). Here we discuss the impact of recurrent HCV on 27 HIV-positive patients who underwent LTx. HIV infection was well controlled post-transplantation. Survival in HIV-positive/HCV-positive patients was shorter compared to a cohort of HIV-negative/HCV-positive patients matched in age, model for end-stage liver disease (MELD) score, and time of transplant, with cumulative 1-, 3- and 5-year patient survival of 66.7%, 55.6% and 33.3% versus 75.7%, 71.6% and 71.6%, respectively, although not significantly (p = 0.07), and there was a higher likelihood of developing cirrhosis or dying from an HCV-related complication in coinfected subjects (RR = 2.6, 95% CI, 1.06-6.35; p = 0.03). Risk factors for poor survival included African-American race (p = 0.02), MELD score > 20 (p = 0.05), HAART intolerance postLTx (p = 0.01), and postLTx HCV RNA > 30000000 IU/mL (p = 0.00). Recurrent HCV in 18 patients was associated with eight deaths, including three from fibrosing cholestatic hepatitis. Among surviving coinfected recipients, five are alive at least 3 years after LTx, and of 15 patients treated with interferon-alpha/ribavirin, six (40%) are HCV RNA negative, including four with sustained virological response. Hepatitis C is a major cause of graft loss and patient mortality in coinfected patients undergoing LTx.

Changes in the immune system are conditioned by nutrition

Undernutrition due to insufficient intake of energy and macronutrients and/or due to deficiencies in specific micronutrients impairs the immune system, suppressing immune functions that are fundamental to host protection. The most consistent abnormalities are seen in cell-mediated immunity, complement system, phagocyte function, cytokine production, mucosal secretory antibody response, and antibody affinity. There is a number of physiological situations such as ageing and performance of intense physical exercise associated with an impairment of some immune parameters' response. Nutrition can influence the extent of immune alteration in both of them. There are also numerous pathological situations in which nutrition plays a role as a primary or secondary determinant of some underlying immunological impairments. This includes obesity, eating disorders (anorexia nervosa and bulimia nervosa), food hypersensitivity and gastrointestinal disorders as some examples. The implications of nutrition on immune function in these disorders are briefly reviewed.

Influence of alcohol consumption on immunological status: a review

The aim of this review is to present and discuss the effect of different levels of alcohol consumption on the immune system. Not only the amount consumed but also the type of alcoholic beverage have to be taken into account in order to determine the consequences on activity, number, distribution, balance, interaction and response of immunocompetent cells. The association between alcohol exposure and the risk of developing an alcohol-related disease is multifactorial. In fact, age, gender, smoking habits, dietary intake and exercise are involved among other factors. The evaluation of the host cellular and humoral immune responses has shown that alcohol may induce some benefits when consumption is moderate. Moreover, those alcoholic beverages that contain antioxidants, such as red wine, could be protectors against immune cell damage. According to the literature consulted, the daily consumption of 10-12 g and 20-24 g of alcohol for women and men, respectively, is considered to be a moderate intake; the type of beverage has been established not to be important when defining moderation. Particular attention is often focused on the U- or J-shaped curve which also suggests that light to moderate drinking produces a protective effect. Such an inverse relationship indicates a reduction of risk for both light and moderate consumers and a higher risk not only for hard drinkers, but also for non-consumers.

The interrelationship between portal and arterial blood flow after adult to adult living donor liver transplantation

BACKGROUND

When adults are transplanted with segmental grafts, disparity between the size of the graft and the native organ is almost universal. These grafts presumably still receive all of the native portal inflow despite a reduced vascular bed and dramatically elevated blood flow may result. The hemodynamic changes after segmental transplantation in adults have not yet been studied and their clinical significance is unknown.

METHODS

Portal venous and hepatic arterial blood flow were measured intraoperatively in right lobe liver donors and recipients with electromagnetic flow probes. Postoperative evolution was monitored in recipients with ultrasonography.

RESULTS

Portal flow to the right lobe ranged from 601 to 1,102 ml/min before resection and from 1,257 to 2,362 ml/min after transplantation. There was a statistically significant linear correlation between the change in portal flow and graft to recipient body weight ratio. Arterial blood flow ranged from 213 to 460 ml/min before resection and from 60 to 300 ml/min after transplantation. Preoperative portal peak systolic velocity was uniformly around 10 cm/sec. Values on postoperative day 1 were increased to 30 cm/sec in recipients of cadaveric organs, to 50 cm/sec in recipients of organs with graft to recipient body weight ratios of more than 1.2%, and to 115 cm/sec in recipients of organs with ratios less than 0.9%. A decreasing tendency was universally observed. Arterial systolic velocity was inversely related to portal systolic velocity. Neither graft dysfunction nor vascular complications occurred.

CONCLUSIONS

The hemodynamic pattern after right lobe transplantation is predictable and intraoperative measurements and ultrasonography are useful for monitoring. The size of the graft influences the magnitude of the hemodynamic changes.

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.

Functional venous anatomy for right-lobe grafting and techniques to optimize outflow

Right-lobe living donor liver transplantation has emerged as an alternative to cadaveric transplantation. An appreciation of the unique anatomy and behavior of the right lobe has emerged and has precipitated technical modifications. Living donors underwent right lobectomy, including preservation of significant inferior hepatic veins. The parenchyma was divided following a plane approximating the right border of the posterior two thirds of the midhepatic vein (MHV), but deviating anteriorly to include the distal one third of the MHV with the graft. Large venous tributaries from segment VIII were preserved. Anastomosis in the recipient was accomplished by means of complete cavoplasty. Significant inferior veins, tributaries to the MHV, and the distal portion of the MHV were reconstructed when technically possible. Forty-eight right-lobe resections and transplantations were performed in the manner described. There were no donor complications attributable to the technique. Forty-six of the 48 recipients are alive, and 44 of the 46 surviving patients have their original graft. Venous tributaries from segment VIII and/or the distal portion of the MHV were reconstructed in only 3 patients. Outflow obstruction was recognized intraoperatively in 2 patients; 1 patient had a caval web excised and the other patient required revision of the main anastomosis. Neither organ was lost. There were no other significant venous complications. The incidence of ascites was the same as that in recipients of whole organs. These methods of parenchymal transection and venous reconstruction resulted in a low rate of complications. The wide anastomosis and collateral pathways between the MHV and right hepatic vein seem to be more critical than reconstruction of tributaries from segment VIII or the distal MHV.

Right lobe living donor liver transplantation: preoperative evaluation of the donor with MR imaging

OBJECTIVE

The purpose of this study was to report our experience in preoperative evaluation of right hepatic lobe donors with a comprehensive MR examination and to compare abdominal MR images, MR cholangiograms, and MR angiograms with findings at surgery, intraoperative cholangiography, and digital subtraction angiography.

MATERIALS AND METHODS

Twenty-eight right hepatic lobe donors underwent preoperative evaluation with MR imaging, MR cholangiography, and MR angiography. Two abdominal radiologists independently and randomly reviewed these studies. Points of assessment included focal and diffuse liver disease, calculation of right lobe volumes, depiction of the biliary tract and ductal anomalies, and depiction of the liver vasculature and vascular anomalies. Comparison was made with intraoperative cholangiograms (n = 20) and digital subtraction angiograms (n = 28).

RESULTS

MR imaging revealed and characterized focal liver lesions in eight of 28 patients. Calculated right lobe volumes agreed with surgically determined volumes within 7% for reviewer 1 and within 15% for reviewer 2. Intrahepatic bile ducts were depicted completely with MR cholangiography in 25 of 28 patients and with intraoperative cholangiography in nine of 20 patients. MR cholangiography revealed ductal anomalies in six patients. MR imaging and MR angiography depicted the portal veins more completely than digital subtraction angiography. MR imaging and MR angiography correctly excluded portal venous anomalies in all patients and revealed surgically confirmed accessory hepatic veins in six of 28 patients. Angiographically confirmed arterial anomalies were correctly detected in three of 28 patients by at least one reviewer on MR imaging and MR angiography.

CONCLUSION

MR imaging, MR cholangiography, and MR angiography provide a comprehensive, accurate means of evaluating donors for factors that may preclude or complicate right hepatic lobe donation.

The adaptive response of the immune system to the particular malnutrition of eating disorders

Despite the seriously undernourished state of patients with anorexia nervosa (AN) and bulimia nervosa (BN), controversial findings have been published regarding some aspects of the immune system that are otherwise impaired in more typical types of malnutrition, such as protein-energy malnutrition. In general, adaptation processes seem to occur enabling immune function to be preserved during long periods of the illness. However, cell-mediated immunity is usually altered in AN and BN as reflected by lymphocyte subset counts and the response to delayed hypersensitivity tests. Regarding the helper/cytotoxic T cell ratio (CD4:CD8), an immunological marker of the nutritional status, the results of our studies on AN and BN patients showed that the duration of the eating disorder and the time when appropriate treatment is achieved are likely contributors to the alteration of this ratio. Despite these findings, it has been repeatedly pointed out that anorexic patients seem to be free of common viral infections at least until the most advanced stages of debilitation. Some hypotheses that could explain the lack of infection symptoms are reviewed. Cytokines and the altered acute phase response to infection, as well as cortisol and leptin, are considered to be potential factors involved in the adaptation processes occurring in these syndromes. Further progress in the knowledge of the psychoneuroendocrine-immune interactions established in AN and BN will be relevant to the understanding of the aetiology and maintenance mechanisms of these pathologies.

In vitro antimicrobial production of beta-lactamases, aminoglycoside-modifying enzymes, and chloramphenicol acetyltransferase by and susceptibility of clinical isolates of Acinetobacter baumannii

Antimicrobial susceptibility testing was performed on 54 epidemiologically unrelated clinical isolates of Acinetobacter baumannii by using a standard agar dilution technique. On the basis of the in vitro activities, imipenem and doxycycline were the most active agents, whereas amikacin, isepamicin, and the new fluorquinolones ciprofloxacin and ofloxacin presented moderate activity. Cephalosporinase activity was found in 98% of the strains, whereas lactamases of TEM type 1 and one with a pI of 7 to 7.5 were present in 16 and 11% of the strains, respectively. Resistance to aminoglycosides was explained by the production of the three classes of aminoglycoside-modifying enzymes, with predominance of aminoglycoside-3'-phosphotransferase VI in 28% of the strains.

Right-lobe living donor liver transplantation

1. Living donor liver transplantation (LDLT) is currently performed at about 30 centers in the United States. 2. Careful and critical evaluation of donor and recipient is required for optimal outcome. 3. Right lobe donation is preferred over left lobe donation in adult LDLT. 4. There has been 1 donor death (<0.3%) in the US experiences. Donor biliary complications occur in approximately 4% of the cases. 5. Recipient survival after adult LDLT in the United States is approximately 88%. Hepatic artery thrombosis occurs in 3% and biliary complications in 18%.

Maternal Body Weight and Gestational Diabetes Differentially Influence Placental and Pregnancy Outcomes

CONTEXT

Maternal obesity and gestational diabetes mellitus (GDM) can both contribute to adverse neonatal outcomes. The extent to which this may be mediated by differences in placental metabolism and nutrient transport remains to be determined.

OBJECTIVE

Our objective was to examine whether raised maternal body mass index (BMI) and/or GDM contributed to a resetting of the expression of genes within the placenta that are involved in energy sensing, oxidative stress, inflammation, and metabolic pathways.

METHODS

Pregnant women from Spain were recruited as part of the "Study of Maternal Nutrition and Genetics on the Foetal Adiposity Programming" survey at the first antenatal visit (12-20 weeks of gestation) and stratified according to prepregnancy BMI and the incidence of GDM. At delivery, placenta and cord blood were sampled and newborn anthropometry measured.

RESULTS

Obese women with GDM had higher estimated fetal weight at 34 gestational weeks and a greater risk of preterm deliveries and cesarean section. Birth weight was unaffected by BMI or GDM; however, women who were obese with normal glucose tolerance had increased placental weight and higher plasma glucose and leptin at term. Gene expression for markers of placental energy sensing and oxidative stress, were primarily affected by maternal obesity as mTOR was reduced, whereas SIRT-1 and UCP2 were both upregulated. In placenta from obese women with GDM, gene expression for AMPK was also reduced, whereas the downstream regulator of mTOR, p70S6KB1 was raised.

CONCLUSIONS

Placental gene expression is sensitive to both maternal obesity and GDM which both impact on energy sensing and could modulate the effect of either raised maternal BMI or GDM on birth weight.

Ethical considerations and rationale of adult-to-adult living donor liver transplantation

Adult-to-adult living donor liver transplantation (ALDLT) is a reality; shortly after its introduction into clinical practice, it is being performed in approximately 50 centers throughout the United States and Europe. The quick development of ALDLT and some deaths among donors repropose old ethical dilemmas and confront the transplant community with new urgent problems. To minimize risks for recipients and, especially, donors, two key questions are addressed: (1) who can or should perform the procedure, and (2) what patient should undergo the procedure. The high risks taken by live donors undergoing a hemihepatectomy seem to be justified by the steadily increasing mortality of adult recipients waiting for transplantation. A comprehensive consent procedure is at the base of responsible decision making for both donors and recipients. In adherence to basic medical criteria, the autonomy of decision of donors and recipients may allow the extension of indications to patients not suitable to undergo transplantation with cadaveric grafts. The broadening of indications is appropriate only in centers with adequate experience and proven expertise in ALDLT. The medical community faces the duty of regulating ALDLT before external influences force undesired policy changes, particularly if not based on medical grounds. Individual centers and patients are ultimately responsible for the correct use of LDLT.