Impact of progestins on estradiol potentiation of the glutamate calcium response

One mechanism by which estrogen may modulate cognitive function is through potentiation of glutamate-mediated rises in intracellular calcium ([Ca2+]i) with resultant effects on neuronal morphology and signaling. Since progesterone is a component of hormone replacement therapy (HRT), we sought to determine whether therapeutically relevant progestins attenuated or blocked estrogen potentiation of glutamate-induced [Ca2+]i rises. 17beta-estradiol and progesterone, alone or in combination, significantly potentiated the rise in [Ca2+]i. When co-administered, progesterone attenuated the estrogen response to the level seen with progesterone alone. In contrast, medroxyprogesterone acetate (MPA) had no effect when administered alone and completely blocked the 17beta-estradiol-induced potentiation when co-administered. These results may have important implications for effective use of HRT to maintain cognitive function during menopause and aging.     

Development and validation of an enzyme-linked immunosorbent assay to measure vitellogenin in the zebrafish (Danio rerio)

In this study, an enzyme-linked immunosorbent assay (ELISA) was developed to quantify vitellogenin (Vtg) in zebrafish (Danio rerio). Zebrafish Vtg (zf-Vtg) was purified from whole-body homogenates of estradiol-exposed zebrafish, and polyclonal antibodies against zf-Vtg were raised. Using purified zf-Vtg as a standard and anti-zf-Vtg antibodies (DR-264), a competitive ELISA method was set up and validated. The working range of the assay is from 1 to 30 ng/ml (20-80% binding), and the detection limit is 0.4 ng/ml for purified zf-Vtg. In whole-body homogenates samples, the practical detection limit is higher than that for purified Vtg (40 ng/ml) due to matrix effect. The intra- and interassay variations were 4.7% and 14%, respectively, at 50% binding (n = 36). Its usefulness to detect changes in Vtg concentration in other cyprinid fish was also tested. In addition, the assay was used to assess Vtg induction in male zebrafish exposed to 17beta-estradiol (E2). Exposure of male zebrafish to 0.1, 1, 10, and 100 microg/L of E2 for 7 d led to a Vtg induction from the lowest concentration. The results show the suitability of the developed ELISA to quantify Vtg inductions in zebrafish, the cross-reactivity of DR264 antibodies with commonly used cyprinids, and the potential of zf-Vtg induction as a sensitive biochemical endpoint that could be used to detect estrogenic properties of chemical substances.     

Increasing applicability of liver transplantation for patients with hepatitis B-related liver disease

Liver transplantation in patients with hepatitis B has been under discussion for 20 years because of inferior results without reinfection prophylaxis; therefore, we analyzed our overall experience with liver transplantation in hepatitis B patients with immunoprophylaxis, particularly the influence of the available antiviral treatment in different periods. From 1988 to 2000, 228 liver transplants in 206 hepatitis B patients were performed. Indications were acute liver failure (10%), hepatitis B virus (HBV) cirrhosis alone (67%) or with hepatitis D virus (HDV) (13%), or hepatitis C virus (HCV) coinfection (7%). All patients received long-term immunoprophylaxis (anti-HBs > 100 U/L). HBV DNA-positive patients were treated before and after surgery with famciclovir or lamivudine since 1993 and 1996, respectively. Since 1993, antivirals also were used for HBV reinfection. The 1-, 5-, and 10-year patient survival rates were 91%, 81%, and 73%. In patients with hepatocellular carcinoma (HCC) (60% 5-year survival, P <.01) or HBV reinfection (69% 5-year survival, P <.01) survival was significantly impaired. Those with HDV or HCV coinfection had a slightly better survival than with HBV monoinfection (P >.05, not significant). Preoperative positive HBV DNA (hybridization-assay) test results were associated with a slightly impaired patient survival (78% 5-year survival, P >.05, not significant versus DNA-negative). Preoperative positive hepatitis B e antigen (HBeAg) predicted significantly worse survival (P <.05 versus negative HBeAg). Graft loss caused by reinfection was most frequent before the availability of antiviral drugs. Two-year patient survival increased from 85% in era I (1988-1993) to 94% in era III (1997-2000, P <.05). The 2-year recurrence rates in these 2 periods were 42% and 8% (P <.05). In conclusion, excellent long-term results can be achieved in hepatitis B patients after liver transplantation with modern strategies, and survival rates are similar to other indications. Based on our experience, hepatitis B patients, including those with active viral replication, should not be excluded from liver transplantation.     

Assessment of brainstem function in Chiari II malformation utilizing brainstem auditory evoked potentials (BAEP), blink reflex and masseter reflex

Brainstem dysfunction was evaluated in 67 patients with myelomeningocele and Chiari II malformation using brainstem auditory evoked potentials (BAEP), blink reflex (BR) and masseter reflex (MR). Signs and symptoms related to Chiari II malformation were observed in 18 patients while 49 patients had normal brainstem findings. BAEP and BR showed a higher sensitivity of brainstem involvement than MR (BAEP=1.0, BR=0.83, MR=0.50). BR, and in particular, MR were of higher accuracy (BR=0.52, MR=0.72) than BAEP (0.39) in separating patients with brainstem signs and symptoms related to Chiari II malformation. We feel that this is due to anatomic and physiologic peculiarities of the brainstem structures mediating BR and MR. Our results suggest that brainstem reflexes can support the decision of further treatment.     

Potent antitumor activity of an auristatin-conjugated, fully human monoclonal antibody to prostate-specific membrane antigen.

Prostate-specific membrane antigen (PSMA) is the prototypic cell-surface marker of prostate cancer and provides an attractive target for monoclonal antibody (mAb) targeted therapies. In this study, a novel antibody-drug conjugate (ADC) was generated by linking a fully human PSMA mAb to monomethylauristatin E (MMAE), a potent inhibitor of tubulin polymerization. The PSMA ADC was evaluated for antitumor activity in vitro and in a mouse xenograft model of androgen-independent human prostate cancer. The PSMA ADC eliminated PSMA-expressing cells with picomolar potency and >700-fold selectivity in culture. When used to treat mice with established human C4-2 tumors, the PSMA ADC significantly improved median survival 9-fold relative to vehicle or isotype-matched ADC (P = 0.0018) without toxicity. Treatment effects were also manifest as significant (P = 0.0068) reduction in serum levels of prostate-specific antigen (PSA). Importantly, 40% of treated animals had no detectable tumor or measurable PSA at day 500 and could be considered cured. The findings support development of PSMA antibody-auristatin conjugates for therapy of prostate cancer.     

Induction of T helper cell type 1 response and elimination of HBeAg during treatment with IL-12 in a patient with therapy-refractory chronic hepatitis B

This study reports the increase of immunoregulatory T helper cell type 1 response and elimination of HBV-DNA during IL-12 therapy in a patient with chronic hepatitis B virus infection who had not responded to three previous interferon-alpha therapies and one treatment with Famciclovir over a period of 6 years. The patient received IL-12 at a dose of 0.5 microgram/kg bodyweight weekly. Peripheral blood mononuclear cells were isolated before and during IL-12 application and incubated for 7 days with specific type 1 (purified protein derivative) and type 2 (tetanus-toxoid) TH cell antigens as well as with a macrophage/monocyte activating antigen (Bacille Calmette-Guérin). In the supernatants cytokines were determined by a double-sandwich ELISA. After 8 weeks HBV-DNA became negative and HBeAg seroconversion to anti-HBeAg occurred. Immunologically the loss of viremia was accompanied by a strong increase of the purified protein derivative-induced production of the type 1 cytokine interferon-gamma (1219 pg/mL before, 13,138 pg/mL after IL-12 therapy). Furthermore, Bacille Calmette-Guérin-induced secretion of the macrophage/monocyte-associated cytokines IL-1, tumor necrosis factor-alpha and granulocyte-macrophage colony-stimulating factor was higher at the end of therapy. This case indicates that IL-12 enhances type 1 T helper cell activity which may be a predisposition for elimination of HBeAg and successful treatment of hepatitis B.     

Exchange transfusion in neutropenic septicemic neonates: effect on granulocyte functions

Depletion neutropenia caused by overwhelming bacterial infection is associated with fatal outcome and is an objective indicator of the severity of sepsis. Studies on controlled evaluation of exchange transfusion in the management of severe neonatal sepsis have not considered neutropenia as an inclusion critcrion, and randomized, controlled trials on evaluation of ncutrophil functions after exchange transfusion are scarce. This prompted us to carry out the present study. Septicemic neonates were enrolled if they had neutropenia and were randomized to undergo exchange transfusion (study group, n = 20) or not (controls, n= 10). Granulocyte functions were assessed using the nitro blue tetrazolium (NBT) reduction test and the staphylococcicidal index. Blood was drawn for granulocyte function tests once from controls and donors, and before, immediately after and 6 h after exchange transfusion in the study group. Mortality was 35% in the study group and 70% in controls. Gram-negative organisms accounted for 80%, in the study group and 90% in controls. Mean total leukocyte count and neutrophil count increased significantly immediately after exchange transfusion and 6 h later. Absolute band count decreased significantly immediately after exchange transfusion and incrcased 6 h later. NBT reduction in septicemic neonates in the study group, as wclras in controls. was significantly decreascd as compared to donor cells. NBT reduction improved significantly immediately after exchange transfusion and 6 h later. The valucs of the perccntage of viable staphylococci recovered from neutrophils also improved significantly immediately after exchange transfusion and 6 h later. We conclude that exchange transfusion with fresh whole blood in severe neonatal septicemia with neutropenia improves survival, increases the neutrophil count and cnhances neutrophil function.