Necessary and sufficient conditions for solvability of the Lewy equation

We find the necessary and sufficient conditions for the local solvability of Lewy's equation, ([unk]/[unk]z + īz [unk]/[unk]t) u = f. If R³ is realized as the boundary of the generalized “upper-half-space” in C², then the conditions are, near a point P [unk] R³, the analytic continuability of the Cauchy-Szegö integral of f past P. In case the sufficient condition is satisfied, solutions are found that satisfy optimal regularity properties. Various generalizations are also given.     

High-energy phosphate metabolism in the exercising muscle of patients with peripheral arterial disease

Patients with peripheral arterial disease (PAD) suffer from impaired muscle function due to insufficient oxygen supply during exercise, mitochondrial damages, unfavourable muscle fibre type distribution and impaired exercise tolerance. These factors influence the symptoms as well as the quality of life in PAD patients and are closely connected to failures of high-energy phosphate metabolism. At onset of muscle exercise, the mitochondrial capacity cannot match the increased demand. The oxygen supply via blood flow must be increased. Meanwhile, anaerobic glycolysis and internal stores of oxygen like mixed venous blood and myoglobin as well as internal stores of high-energy phosphates like phosphocreatine (PCr) are adducted for the provision of additional adenosine-triphosphate (ATP), which is consumed by the ATPase at the myofibrils in order to fuel muscle contraction. Since the ATP production is insufficient, this phase (anaerobic phase) is characterized by a progressive decrease in PCr, which can be accurately measured by phosphorus 31 magnetic resonance spectroscopy (³¹p MRS). If the oxygen supply is improved, the mitochondrial capacity can match the increased metabolic demand. This phase is the aerobic phase, which is indicated by a steady-state of PCr hydrolysis. In PAD patients or experimental models of peripheral ischemia, the anaerobic phase is prolonged or does not pass into the aerobic phase resulting in exercise abortion. This review summarizes the results of ³¹p MRS studies investigating the high-energy phosphate metabolism during ischemic exercise in healthy humans and during ramp or incremental exercise in PAD patients.     

Effectiveness of the polysaccharide pneumococcal vaccine among HIV-infected persons in Brazil: a case control study

Background  

Polysaccharide pneumococcal vaccine is recommended for use in HIV-infected adults in Brazil but there is uncertainty about its effectiveness in this patient population.     

Trends in Alcohol‐Related Traffic Risk Behaviors Among College Students

Background: Alcohol‐impaired driving is a major public health problem. National studies indicate that about 25% of college students have driven while intoxicated in the past month and an even greater percentage drive after drinking any alcohol and/or ride with an intoxicated driver. The purpose of this investigation was to examine the change in these various alcohol‐related traffic risk behaviors as students progressed through their college experience. Methods: A cohort of 1,253 first‐time first‐year students attending a large, mid‐Atlantic university were interviewed annually for 4 years. Repeated measures analyses were performed using generalized estimating equations to evaluate age‐related changes in prevalence and frequency of each behavior (i.e., ages 19 to 22). Results: At age 19, 17%_wt of students drove while intoxicated, 42%_wt drove after drinking any alcohol, and 38%_wt rode with an intoxicated driver. For all 3 driving behaviors, prevalence and frequency increased significantly at age 21. Males were more likely to engage in these behaviors than females. To understand the possible relationship of these behaviors to changes in drinking patterns, a post hoc analysis was conducted and revealed that while drinking frequency increased every year, frequency of drunkenness was stable for females, but increased for males. Conclusions: Alcohol‐related traffic risk behaviors are quite common among college students and take a significant upturn when students reach the age of 21. Prevention strategies targeted to the college population are needed to prevent serious consequences of these alcohol‐related traffic risk behaviors.     

Genomic lesions associated with a different clinical outcome in diffuse large B‐Cell lymphoma treated with R‐CHOP‐21

Despite recent therapeutic improvements, the clinical course of diffuse large B‐cell lymphoma (DLBCL) still differs considerably among patients. We conducted this retrospective multi‐centre study to evaluate the impact of genomic aberrations detected using a high‐density genome wide‐single nucleotide polymorphism‐based array on clinical outcome in a population of DLBCL patients treated with R‐CHOP‐21 (rituximab, cyclophosphamide, doxorubicine, vincristine and prednisone repeated every 21 d). 166 DNA samples were analysed using the GeneChip Human Mapping 250K NspI. Genomic anomalies were analysed regarding their impact on the clinical course of 124 patients treated with R‐CHOP‐21. Unsupervised clustering was performed to identify genetically related subgroups of patients with different clinical outcomes. Twenty recurrent genetic lesions showed an impact on the clinical course. Loss of genomic material at 8p23.1 showed the strongest statistical significance and was associated with additional aberrations, such as 17p‐ and 15q‐. Unsupervised clustering identified five DLBCL clusters with distinct genetic profiles, clinical characteristics and outcomes. Genetic features and clusters, associated with a different outcome in patients treated with R‐CHOP, have been identified by arrayCGH.     

Adult hippocampal neurogenesis is functionally important for stress-induced social avoidance

The long-term response to chronic stress is variable, with some individuals developing maladaptive functioning, although other “resilient” individuals do not. Stress reduces neurogenesis in the dentate gyrus subgranular zone (SGZ), but it is unknown if stress-induced changes in neurogenesis contribute to individual vulnerability. Using a chronic social defeat stress model, we explored whether the susceptibility to stress-induced social avoidance was related to changes in SGZ proliferation and neurogenesis. Immediately after social defeat, stress-exposed mice (irrespective of whether they displayed social avoidance) had fewer proliferating SGZ cells labeled with the S-phase marker BrdU. The decrease was transient, because BrdU cell numbers were normalized 24 h later. The survival of BrdU cells labeled before defeat stress was also not altered. However, 4 weeks later, mice that displayed social avoidance had more surviving dentate gyrus neurons. Thus, dentate gyrus neurogenesis is increased after social defeat stress selectively in mice that display persistent social avoidance. Supporting a functional role for adult-generated dentate gyrus neurons, ablation of neurogenesis via cranial ray irradiation robustly inhibited social avoidance. These data show that the time window after cessation of stress is a critical period for the establishment of persistent cellular and behavioral responses to stress and that a compensatory enhancement in neurogenesis is related to the long-term individual differences in maladaptive responses to stress.     

Evaluation of RepliVAX WN,a Single-Cycle Flavivirus Vaccine,in a Non-Human Primate Model of West Nile Virus Infection

West Nile virus (WNV) causes serious neurologic disease, but no licensed vaccines are available to prevent this disease in humans. We have developed RepliVAX WN, a single-cycle flavivirus with an expected safety profile superior to other types of live-attenuated viral vaccines. In this report we describe studies examining RepliVAX WN safety, potency, and efficacy in a non-human primate model of WNV infection. A single immunization of four rhesus macaques with RepliVAX WN was safe and elicited detectable neutralizing antibody titers and IgM and IgG responses, and IgG titers were increased in two animals that received a second immunization. After challenge with WNV, three of four immunized animals were completely protected from viremia, and the remaining animal showed minimal viremia on one day. In contrast, the unvaccinated animal developed viremia that lasted six days. These results demonstrate the efficacy and safety of RepliVAX WN in this primate model of WNV infection.     

Prognostic significance of leukopenia at the time of diagnosis in acute myeloid leukemia

We investigated the clinical significance of leukopenia at the time of diagnosis in a cohort of 225 patients with newly diagnosed acute myeloid leukemia (AML) at a single institution. Leukocyte count was treated as a continuous variable and, using a receiver operating characteristic curve (ROC), a cutoff of 3,600/μL had the best sensitivity and specificity for remission (complete remission [CR]), relapse-free survival [RFS], and overall survival [OS]). In a multivariable model, leukopenia at diagnosis had no effects on CR (hazard ratio [HR] = 2.02; confidence interval [CI], 0.9-4.3; P = .07), RFS (HR = 0.93; CI, 0.5-1.5; P = .8), or OS (HR = 1.05; CI, 0.7-1.5; P = .7). No differential expression of cell surface molecules (CD34, c-Kit, CXCR4, PECAM, VLA2, VLA-, VLA4, VLA5, and FLT3) was observed on simultaneously obtained marrow and blood blasts in the high- vs. low-leukocyte groups. We conclude that leukopenia at diagnosis carries no prognostic significance in AML.     

t(8;21) (q22;q22) Acute myelogenous leukemia in México: A single institution experience

We analyze the prevalence and clinical features of a group of patients with t(8;21) (q22;q22) acute myeloblastic leukemia, identified in a single institution in México over a 10-year period. Fifteen patients presented at the Centro de Hematología y Medicina Interna de Puebla from February 1995 to August 2005; only nine were treated and followed in the institution. Median age was 24 years, (range 7–49); there was only one male. According to the French–American–British (FAB) morphological classification of leukemia, the morphology was M2 in four cases, M4 in three cases, M3 in one case and M0 in one. In addition to the myeloid markers, lymphoid markers were identified in 6 patients. Patients were induced to remission with combined chemotherapy and three subsequently underwent bone marrow transplantation (BMT). The median overall and disease-free survival has not been reached, being above 3390 days, the probability of survival at this time was 73%. In this single-center experience in México, we found that the t(8;21) (q22;q22) variant of leukemia was more frequent than in Caucasian populations, that the co-expression of lymphoid markers in the blast cells is very frequent and that this malignancy is associated with a relatively good prognosis.     

Long-term Results after Successful Extracorporeal Gallstone Lithotripsy: Outcome of the First 120 Stone-free Patients

Background: Long-term results after successful extracorporeal shock wave lithotripsy (ESWL) of symptomatic gallbladder stones are determined by stone and complaint recurrence. The long-term outcomes of the first successfully treated patients of our Department are presented. Methods: The first consecutive 120 patients with symptomatic gallbladder stones who became stone-free after ESWL plus oral bile acids in the years 1986 and 1987 were included in this study. They were followed up at 1-to 2-year intervals clinically and by ultrasonography until April 1998. Recurrence of stones and biliary symptoms and subsequent treatment were recorded. The effect of various factors on recurrence was analyzed. Results: Median follow-up time was 6.0 years for all patients and 8.8 years for patients without recurrence (range, 0-11.2 years for both). Actuarial recurrence probability was 1.9%-16.6% per year reaching 60.2% (49.9%, 70.3%) (95% confidence interval) after 10 years. Patients with stone recurrence revealed significantly more stones before ESWL than patients without recurrence (P < 0.03). Other factors were not significantly different. The majority of stone recurrences were symptomatic requiring retreatment, mostly cholecystectomy. Conclusion: The probability of gallbladder stone recurrence after successful ESWL remains high during a decade of follow-up. Many patients require repeated nonsurgical treatment or cholecystectomy. Thus long-term results are unsatisfactory and ESWL should be offered only exceptionally.