The incidence of painful crisis in homozygous sickle cell disease: correlation with red cell deformability

To determine whether the vasoocclusive severity of homozygous sickle cell (SS) disease is influenced by cellular dehydration, we correlated the incidence of painful crisis with steady-state measurements of red cell hydration. Sixteen children with SS disease were followed for 3.3 to 8 years (mean, 6.8 years), and a single crisis rate was calculated for each patient. At the time of well visits, cellular hydration was assessed by measuring cell deformability, the percentage of red cells with a density greater than or equal to 1.1056 g/mL, and the percentage of irreversibly sickled cells (ISC). The incidence of painful crisis showed a strong positive correlation with Omax, a deformability measurement reflecting cellular hydration (r = .84, P less than .002), and with hemoglobin concentration (r = .59, P = .04). That is, higher crisis rates were observed in patients with less dehydrated, more deformable red cells and also in patients with higher hemoglobin concentrations. Furthermore, cell deformability and hemoglobin concentration were independent predictors of the incidence of painful crisis, which is consistent with separate effects of these two red cells parameters on vasoocclusive severity.     

Immunopathogenesis of hepatitis B virus recurrence after liver transplantation

BACKGROUND AND AIMS: Hepatitis B virus (HBV) recurrence after orthotopic liver transplantation is associated with inflammatory graft changes, despite immunosuppression and donor/recipient HLA mismatch. We investigated whether immune mechanisms are involved in the pathogenesis of hepatitis B after liver transplantation. METHODS: The virus-specific T helper (Th) cell response, activation of Th1/Th2 subpopulations, donor/recipient HLA, and expression of tumor necrosis factor (TNF)-alpha/TNF receptors were determined in 28 patients who underwent transplantation for HBV-related cirrhosis (17 with HBV recurrence and 11 without recurrence) in comparison to 30 nontransplant patients with chronic hepatitis B. RESULTS: Orthotopic liver transplantation recipients with HBV recurrence showed significant hepatitis B core antigen-specific T-cell proliferation, comparable to nontransplant patients, which was not present in transplant recipients without recurrence. In addition, hepatic and serum interleukin (IL)-2, interferon-gamma, and TNF-alpha were enhanced, without changes in IL-4 and IL-10. Phenotypically, hepatic infiltrates in allografts with HBV recurrence were comprised of CD4+ lymphocytes and macrophages with a correlation between interferon-gamma- and TNF-alpha-producing cells and the degree of necroinflammatory activity. There was a marked up-regulation of both TNF-alpha receptors, significantly greater than in nontransplant patients. CONCLUSIONS: These findings suggest that despite immunosuppression, HLA class I-independent immune mechanisms have a significant pathogenic role in liver damage associated with HBV recurrence after liver transplantation.     

Liver transplantation for hepatic cirrhosis in cystic fibrosis

Five children with cystic fibrosis complicated by hepatic cirrhosis received liver grafts. They all had portal hypertension with varices and three had variceal bleeding; respiratory function was only moderately impaired, but four were colonised with pseudomonas and one with aspergillus. Liver transplantation was well tolerated and there was no increase in respiratory or other early postoperative complications. Four of the children were fully well from 14 to 35 months after transplantation; the most recently transplanted had problems from a biliary stricture. In spite of the need for immunosuppression there was no increase in infection and respiratory function improved or remained stable. Once the children were stabilised after transplantation their nutrition and general health were greatly improved.     

High dose vitamin A supplementation in the course of pneumonia in Vietnamese children

We carried out a randomized, placebo-controlled, double-blinded trial to evaluate the effect on morbidity of high dose oral vitamin A, given on hospital admission to 592 children aged 1–59 months with moderate and severe pneumonia. Severely underweight children were not included, but 45% were moderately underweight. The vitamin A and placebo groups were comparable in baseline characteristics. Four patients died. Among all of the surviving children, no differences were found regarding mean time for normalization of fever, respiratory rate and time of hospitalization. Stratification for moderate malnutrition, degree of pneumonia, age and sex revealed moderately malnourished vitamin A-supplemented children to have a shorter time of hospitalization ( p = 0. 04), due to an effect in females aged > 12 months ( p = 0. 02) and females with very severe pneumonia ( p = 0. 048). This study indicates that, in developing countries like Vietnam, supplementation with vitamin A in children with pneumonia could shorten the recovery rate in the ones that are undernourished, especially females > 1 y old.     

Ooplasmic injection of elongating spermatids for the treatment of non- obstructive azoospermia

We applied the technique of ooplasmic elongating spermatid injection to the treatment of non-obstructive azoospermia. Mature oocytes were injected with elongating spermatids isolated from testicular biopsy material obtained from 13 non-obstructed azoospermic men. Seventy-three oocytes were successfully injected with elongating spermatids and were then cultured for 36 h. At 13 h post-injection 68 oocytes were found to be activated and 52 of them were fertilized. Forty-one 2- to 4-cell stage embryos developed from normally fertilized oocytes were transferred. At least two embryos were transferred to each female partner. Two pregnancies were achieved. Elongating spermatid injection may have a role in the treatment of non-obstructive azoospermia.      

Cyclosporine pharmacokinetics in liver transplant recipients: evaluation of results using both polyclonal radioimmunoassay and liquid chromatographic analysis

Summary Pharmacokinetic variables were derived from cyclosporine measurements using liquid chromatography (HPLC) and radioimmunoassay with a non-selective polyclonal antibody (PARIA) in 11 orthotopic liver transplant recipients studied in paired oral and intravenous studies both before and after permanent clamping of the biliary T-tube.After oral drug administration, mean areas under blood cyclosporine concentration versus time curves before clamping were around 5.2-fold greater by PARIA than HPLC but 2.9-fold greater after clamping and closer to comparable values after intravenous cyclosporine (2.5 and 2.3-fold, respectively).Cyclosporine clearance was smaller by PARIA than HPLC (mean 7.3 versus 3.3 ml · min^–1 · kg^–1, respectively, before clamping). Both values decreased by 25% after clamping (to 5.5 and 2.4 ml · min^–1 · kg^–1, respectively), although there was no significant change in distribution or elimination half-lives (around 0.5 and 8 h, respectively).The mean bioavailability of oral cyclosporine increased significantly after clamping in 9 patients (from 10.6% to 28.1% by HPLC and from 14.8 to 35.1% by PARIA) but in two patients who developed the vanishing bile duct syndrome values fell to < 10% and the proportional overestimation of cyclosporine concentrations by PARIA increased.Clamping had no significant effect on the mean apparent volumes of distribution but values of V_z were approximately twice those of V_ss (around 2.6 and 1.3 l · kg^–1 by PARIA and HPLC respectively). Mean half lives after clamping were shorter following oral than intravenous cyclosporine (t_1/22 around 15 h enterally versus 8 h parenterally).These data suggest delays in cyclosporine absorption and significant first pass metabolism which may contribute to higher PARIA:HPLC ratios after oral dosing and to reduced bioavailability before clamping.     

Molecular epidemiology and interferon susceptibility of the natural recombinant hepatitis C virus strain RF1_2k/1b

BACKGROUND: Hepatitis C virus (HCV) genotype is an important determinant of virological response to antiviral therapies. Currently, there are no data available on the molecular epidemiology and interferon susceptibility of the natural intergenotypic recombinant RF1_2k/1b (RF1) strain. METHODS: Genotyping and RF1-PCR screening were performed on samples from 604 HCV RNA-positive individuals from 7 countries. uPA/SCID mice carrying human hepatocytes (chimeric mice) were infected with the RF1_2k/1b strain, and the susceptibility of the strain to interferon and ribavirin was compared with the susceptibilities of 2 different strains of genotype B, used as references. RESULTS: Six new RF1 cases were identified in this study; 5 (2%) of 281 in Russia and 1 (1%) of 90 in Uzbekistan. Phylogenetic analyses based on Core/E1 and NS5b indicated that all RF1 representatives share a common evolutionary ancestor. Infection with RF1 was established in chimeric mice. Reduction of RF1 viral load was observed in response to 3 injections of 3 microg/kg pegylated-interferon alpha-2a alone or in combination with 50 mg/kg of ribavirin (0.5 or 1.4 log-copies/mL). CONCLUSIONS: All identified RF1-type strains appear to be introduced from a single source, suggesting that intergenotypic recombination in HCV is sporadic and not associated with cocirculation of different genotypes in a population. The RF1 strain in this study was responsive to interferon in vivo.     

APOBEC and iNOS are not the main intracellular effectors of IFN-gamma-mediated inactivation of Hepatitis B virus replication

BACKGROUND/AIM: Interferon-gamma (IFN-gamma) produced by activated T-cells is the principle mediator of non-cytolytic Hepatitis B virus (HBV) inactivation; however the intracellular pathways responsible are poorly defined. We investigated the role of IFN-gamma-inducible nitric oxide synthase (iNOS) and APOBEC3 (A3) enzyme family in the inhibition of HBV replication by IFN-gamma. METHODS: Hepatoma-cell lines transfected with HBV DNA were treated with IFN-gamma. Viral replication, iNOS and A3 mRNAs were quantitated by TaqManPCR and the direct nitric oxide (NO) effect on HBV replication was investigated using an NO-donor. A3G antiviral activity was verified by co-transfection with its inhibitor, human immunodeficiency virus (HIV)-associated virion infectivity factor (Vif). RESULTS: IFN-gamma caused a dose-dependent reduction (>50%) of HBV DNA in the absence of cytotoxicity. Although iNOS mRNA increased 45-fold in IFN-gamma treated cells, NO2- was not detectable in supernatants and the use of an NO-donor did not inhibit HBV replication. A3 enzyme mRNAs varied between cells and were >10-fold higher in lymphocytes than in liver tissue. IFN-gamma up-regulated A3G mRNA by three-fold, associated with significant HBV DNA decrease. However, A3G degradation by Vif did not abolish the antiviral effect of IFN-gamma against HBV. CONCLUSIONS: IFN-gamma inhibits HBV replication and up-regulates both iNOS and A3G. However, other pathways appear to have a greater role in IFN-gamma-induced HBV inactivation in the liver.     

Multivessel sequential bypass grafting without cardiopulmonary bypass

Background Multivessel sequential coronary artery bypass grafting without cardiopulmonary bypass has become a reality. Initially the revascularization of posterior coronary arteries (obtuse marginal branches of the circumflex artery) was difficult due to access and difficulty in stabilization of the heart as well as compromising the haemodynamic status of the heart. With stabilization of the heart with Octopus II (Medtronic, Inc. Minnesota, USA) we have demonstrated that sequential grafts as well as composite arterial grafts can easily and safely be used in complete arterial revascularization of the myocardium. Methods From January 1, 1996 till December 31, 1999, 832 consecutive patients underwent coronary artery bypass surgery without cardiopulmonary bypass. From July 1998, seventy-nine patients operated had atleast 1 conduit used as a sequential graft and 12 patients had composite ‘Y’ grafts. Before July 1999, 67 patients (61 sequential and 6 ‘Y’ conduits) underwent surgery without mechanical stabilization (Group A) and after July 1999 in 24 patients (18 sequential and 6 ‘Y’ conduits) mechanical stabilization (Octopus II) was used. Results Total number of sequential anastomosis including composite grafts was not significantly different in both groups. But due to Octopus II stabilization, number of anastomosis in composite ‘Y’ graft group significantly increased from 2.96 ±0.2 to 4.02 ±0.3. Also intramyocardial coronary artery revascularization which was only 10.4% in Group A increased to 20.8% in Group B. In Group A only 8.9% composite grafts were performed while in Group B it was 25% which was statistically significant. Conclusions Cardiac stabilization with Octopus II has improved ability for revascularization of remote coronary arteries arising from circumflex. Although overall anastomoses have not increased, the number of patients receiving composite grafts using all arterial conduits have increased significantly. Patency rates of all sequential conduits as well as composite grafts have remained equally good in both groups.