Uncertainties in transpiration estimates.

arising from S. Jasechko et al. Nature 496, 347-350 (2013)10.1038/nature11983How best to assess the respective importance of plant transpiration over evaporation from open waters, soils and short-term storage such as tree canopies and understories (interception) has long been debated. On the basis of data from lake catchments, Jasechko et al. conclude that transpiration accounts for 80-90% of total land evaporation globally (Fig. 1a). However, another choice of input data, together with more conservative accounting of the related uncertainties, reduces and widens the transpiration ratio estimation to 35-80%. Hence, climate models do not necessarily conflict with observations, but more measurements on the catchment scale are needed to reduce the uncertainty range. There is a Reply to this Brief Communications Arising by Jasechko, S. et al. Nature 506, http://dx.doi.org/10.1038/nature12926 (2014).

Failure of B-cold lymphocytotoxins to enhance cadaveric renal allograft survival.

In a three-year period between January 1980 and December 1982, 242 consecutive cadaver transplant recipients in one center were tested before transplantation by cytotoxicity against a random panel of T and B lymphocytes at 5 degrees C and 37 degrees C incubation. They were also tested for HLA-A, B, and DR antigens. Kidney transplants were carried out with the primary objective of achieving a two-DR match. Kidney transplants were carried out only in the absence of T-warm positive cross-matches. All patients were followed for a minimum period of one year after transplant. There have been no exclusions, and all causes of failure, including death, have been counted as graft losses. Patients were stratified according to HLA-A, B, and DR matches and were also divided into high-antibody and low-antibody groups. The recipients with no antibodies had the best one-year graft survival (66%). Recipients with B-cold antibodies did not have enhanced one-year graft survival (51%). Recipients with B-warm antibodies did indifferently (56%). The worst results were seen in recipients who had pretransplant T-warm antibodies (42%) though the number of patients in this group was small.

HLA matching at a single kidney transplant center.

Over 1000 patients were analyzed in two different time intervals, 1978-1983 and 1984-1989; these corresponded to patient groups not treated with cyclosporine and treated with cyclosporine. Analysis of mismatching showed that there was a significant (P less than 0.05) longterm matching effect in the precyclosporine, era with 0 HLA-DR-mismatched recipients having a 9.5-year half-life compared with a 3-year half-life for the 2 HLA-DR-mismatched transplant recipients. The trend was similar for the cyclosporine-treated groups, but not significant. Risk factors for donor age and race of the recipient (P less than 0.05) were identified in the cyclosporine-treated group. Graft survival in the high-risk patient populations was 70% or better in the 0, 1 HLA-ABDR-mismatched groups as compared with less than 60% graft survival in the high-risk transplant recipients with 2-6 HLA-ABDR mismatches. In the cyclosporine era the HLA-ABDR 0, 1-mismatched patient groups showed a significantly better graft survival than was found in all other categories and at all time intervals analyzed. Matching is a way to ameliorate some of the high risk potential associated with less than optimal donor or recipients.

Risks of transplanting kidneys from hepatitis B surface antigen-negative, hepatitis B core antibody-positive donors.

BACKGROUND: As the number of patients on the United States kidney transplant list increases, investigation into the utility of transplanting organs formerly considered marginal or undesirable has intensified. Using kidneys from hepatitis B surface antigen (HBsAg)-positive donors is thought to place recipients at excessive risk of graft failure, morbidity, and mortality. However, the risks of using kidneys from HBsAg-negative but hepatitis B core antibody (HBcAb)-positive donors have not been defined. METHODS: Between 1990 and 1994, our group transplanted 1067 cadaveric kidneys, including 38 from HBsAg(-)/HBcAb(+) donors. Of these 38 kidneys, 27 were transplanted into HBcAb(-) recipients (group 1) and 11 were transplanted into HBcAb(+) recipients (group 2). Group 1 and 2 patients received no hepatitis immunoglobulin therapy after transplantation and received the same immunosuppression and rejection therapies as recipients of kidneys from HBcAb(-) donors. RESULTS: After transplantation, none of the group 1 patients became HBsAg(+), three became hepatitis B surface antibody (HBsAb)-positive, and two became HBcAb(+). Of the group 2 patients, none became newly HBsAg(+) or HBsAb(+). No patient receiving a kidney from an HBsAg(-)/HBcAb(+) donor developed signs or symptoms of clinical hepatitis B. Graft and patient survival rates were similar in both groups and similar to the rates of the 1029 recipients of kidneys from HBcAb(-) donors. CONCLUSIONS: Recipients of kidneys from HBsAg(-)/HBcAb(+) donors are at a small risk of hepatitis B seroconversion but are at no excess risk of graft failure or short-term morbidity or mortality.

Outcome of en bloc and single kidney transplantation from very young cadaveric donors.

BACKGROUND: The optimal use of very young cadaveric kidneys (from donors less than 4 years old) remains controversial. High rates of technical complications and poor functional results compared with adult donor kidneys have been reported. The use of en bloc transplantation to overcome these problems has been advocated, although en bloc transplantation halves the number of potential transplants from very young donors. METHODS: We studied the technical and functional results of 91 transplants from very young donors performed at our institution between 1984 and 1995. This included 59 single and 22 en bloc procedures involving first transplants and 7 single and 3 en bloc procedures involving retransplantation. Individual surgeon preference dictated the use of either the single or en bloc technique. Kidneys smaller than 6 cm tended to be transplanted en bloc, and lighter patients were generally given preference for receiving pediatric kidneys. Patients received sequential cyclosporine-based quadruple immunosuppression. RESULTS: En bloc kidneys had a 1-year and 5-year graft survival of 82% and 70%, respectively. Single kidneys had a 1-year and 5-year graft survival of 64% and 40%. Kidneys that avoided acute rejection episodes and that were transplanted into heavier or male recipients had better long-term survival. Kidneys from donors less than 2 years old did poorly whether transplanted en bloc or singly. Better HLA matching improved short-term, but not long-term, graft survival, whereas cold ischemic time did not have statistically significant association with differences in graft survival. Eleven percent of the transplants had ureteral leaks, but only one kidney was lost. Ten transplants had vascular complications leading to graft loss, whereas two episodes of arterial stenosis were successfully treated with percutaneous angioplasty. CONCLUSIONS: En bloc transplantation optimizes the outcome of transplantation with very young kidneys. We recommend induction therapy and cyclosporine immunosuppression with cyclosporine levels similar to adult target levels to minimize rejection episodes and, thus, improve outcome. These kidneys should be distributed nationally, because better HLA matching is associated with improved short-term graft survival. Our high ureteral leak rate indicates that alternatives to unstented ureteroneocystostomy should be considered.

Incidence of new-onset hypercholesterolemia in renal transplant patients treated with FK506 or cyclosporine.

In this study, we compare cholesterol levels during the first year after renal transplantation in FK506 (Prograf)- and cyclosporine-treated patients matched for cumulative first-year steroid dose and hypercholesterolemia risk factors. All patients had pretransplant cholesterol levels < 200 mg/dl. At 3 months posttransplant, 68% of the cyclosporine-treated patients had at least one cholesterol level greater than 200 mg/dl compared with 30% of the FK506-treated patients (P < 0.05). At the end of the year, 26% of FK506- and 67% of cyclosporine-treated patients remained hypercholesterolemic (P < 0.05). We conclude that cyclosporine has inherently more effect on cholesterol levels than FK506 during the first year after kidney transplantation.

Hyperacute and acute kidney graft rejection due to antibodies against B cells.

Because of the perception of its uncertain clinical significance, the B cell crossmatch is not universally performed before renal transplantation. Even though sporadic cases of hyperacute rejection associated with B cell antibodies have been reported, doubts remain in light of other studies suggesting no effect on graft survival. This report describes 4 cases of graft rejection (3 hyperacute and 1 acute) that occurred in patients with anti-B-cell antibodies specific against donor HLA-DR or DQ antigens. Absence of anti-donor class I antibodies was confirmed in all cases by 2-color flow cytometry. Strong evidence for an antibody-mediated mechanism was found in one patient with anti-class I and anti-class II antibodies in serum transplanted with a class II mismatched kidney. In this case, only anti-class II antibodies were recovered in the eluate of the nephrectomy specimen. These four cases were compiled from three different institutions over a four-year period, which confirms the infrequent occurrence of these events. While anti-class II antibodies may not always be detrimental for graft survival, these results also confirm that they have the potential to cause hyperacute or acute graft loss. We conclude that the information provided by the B cell crossmatch should be available at the time that a decision to proceed with a renal transplant is made.

Diagnostic tools in Lyme borreliosis: clinical history compared with serology.

The occurrence of a history of clinical Lyme borreliosis and the prevalence of positive antibodies to Borrelia burgdorferi were studied in 431 Dutch hunters. The majority of the hunters (336 or 78%) did not report any complaints and had no positive IgG antibodies to B. burgdorferi. Sixty-five hunters (15.1%) had no clinical manifestations but did not have positive antibodies to B. burgdorferi. Only 1.9% of the population studied had had past symptoms of definite or probable Lyme borreliosis. Likelihood ratios were high (21.3) for the recognition of erythema migrans, but much lower for tick bites (3.6) or positive IgG Lyme serology (3.5). Clinical history turned out to be a more powerful diagnostic tool than Lyme serology.

Canine Lyme disease in Belgium.

Lyme borreliosis is a multisystem disease caused by the tick-borne spirochaete Borrelia burgdorferi. In addition to causing human illness, borreliosis has been recorded in many species of mammals, including domestic animals which come into contact with the infected tick vector. This paper describes the first two cases to the authors' knowledge of Lyme borreliosis in dogs in Belgium. Both animals suffered recurrent lameness and general prostration. In addition, one of the dogs had recurrent paralysis of nerves V, VII, IX and X, leading to dysphagia and total bilateral paralysis of the mandibular muscles. This complication of Lyme borreliosis has been well documented in human pathology, but has not previously been recorded in the veterinary literature.