Deficient brain RNA polymerase and altered nucleolar structure persists until day 8 after perinatal asphyxia of the rat

RNA polymerases (POL) are integral constituents of the protein synthesis machinery, with POL I and POL III coding for ribosomal RNA and POL II coding for protein. POL I is located in the nucleolus and transcribes class I genes, those that code for large ribosomal RNA. It has been reported that the POL system is seriously affected in perinatal asphyxia (PA) immediately after birth. Because POL I is necessary for protein synthesis and brain protein synthesis was shown to be deranged after hypoxic-ischemic conditions, we aimed to study whether POL derangement persists in a simple, well-documented animal model of graded global PA at the activity, mRNA, protein, and morphologic level until 8 d after the asphyctic insult. Nuclear POL I activity was determined according to a radiochemical method; mRNA steady state and protein levels of RPA4O-an essential subunit of POL I and III-were evaluated by blotting methods; and the POL I subunit polymerase activating factor-53 was evaluated using immunohistochemistry. Silver staining and transmission electron microscopy were used to examine the nucleolus. At the eighth day after PA, nuclear POL I decreased with the length of the asphyctic period, whereas mRNA and protein levels for RPA4O were unchanged. The subunit polymerase activating factor-53, however, was unambiguously reduced in several brain regions. Dramatic changes of nucleolar morphology were observed, the main finding being nucleolar disintegration at the electron microscopy level. We suggest that severe acidosis and/or deficient protein kinase C in the brain during the asphyctic period may be responsible for disintegration of the nucleolus as well as for decreased POL activity persisting until the eighth day after PA. The biologic effect may be that PA causes impaired RNA and protein synthesis, which has been already observed in hypoxic-ischemic states.     

Fine-needle aspiration in the evaluation of nucleated red blood cells in the human placenta

OBJECTIVE: The purpose of this study was to evaluate the correlation between placental and umbilical cord nucleated red blood cell counts. STUDY DESIGN: Eighty placentas and their matched umbilical cord blood samples were collected prospectively immediately after delivery. In vitro fine-needle aspiration biopsy specimens were used to obtain placental tissue samples. Nucleated red blood cells were counted by both manual microscopy and flow cytometry. Statistical analysis included Wilcoxon signed rank test and Spearman correlation. RESULTS: The median nucleated red blood cell counts/100 white blood cell counts for manual microscopy in umbilical cord blood; placental samples were 7.5 and 3.0, respectively (P <.0001). The median nucleated red blood cell counts for flow cytometric determination in umbilical cord blood and placental samples were 11.3 and 8.6, respectively (P <.0001). The Spearman correlation between manually counted umbilical cord blood samples and the placental tissue specimens was 0.66 (P <.0001). The Spearman correlation between flow cytometrically counted umbilical cord blood nucleated red blood cell and nucleated red blood cell counts that were obtained from the placenta was statistically significant (r = 0.74, P <.0001). The Spearman correlation between manual microscopy and flow cytometry for umbilical cord samples and their matched placental tissue specimens were 0.80 and 0.58, respectively, with all probability values at <.0001. CONCLUSION: Previous studies have reported an association between acute and chronic hypoxia and elevated nucleated red blood cells. Our results indicate that in vitro placental nucleated red blood cell counts correlate with umbilical cord nucleated red blood cell counts and suggest that antenatal evaluation of fetal nucleated red blood cells could be achieved by placental fine-needle aspiration biopsy.     

Costimulation via OX40L expressed by B cells is sufficient to determine the extent of primary CD4 cell expansion and Th2 cytokine secretion in vivo

The development of effector and memory CD4 cell populations depends upon both T cell receptor (TCR) engagement of peptide/major histocompatibility complex (MHC) class II complexes and ligation of costimulatory molecules with counter receptors on antigen-presenting cells (APCs). We showed previously that sustained interactions with APCs could be crucial for optimal expansion of CD4 cells and for development of effectors that secrete cytokines associated with Th2 cells. Using an adoptive transfer model with TCR transgenic CD4 cells, we now show that responses of CD4 cells primed in B cell-deficient mice become aborted, but are fully restored upon the transfer of activated B cells. Although B cells have the capacity to secrete multiple cytokines that could affect CD4 priming, including IL-4, we were unable to distinguish a role for cytokines that are secreted by B cells. However, B cell costimulation via the OX40L/OX40 pathway that has been implicated in CD4 cell expansion, survival, and Th2 development was required. Th2 but not Th1 responses were impaired in OX40L-deficient recipients and normal responses were restored with OX40L sufficient B cells. The results suggest that without engagement of OX40L on B cells, CD4 cell responses to many protein Ag would be dominated by Th1 cytokines. These data have important implications for strategies to achieve optimal priming of CD4 subsets.     

Aging-related changes in release of growth hormone and luteinizing hormone in female rhesus monkeys

A decline in somatic function with aging in women is associated with a decrease in GH release and a loss of estrogen after menopause. As an initial step to establish a monkey model for the neuroendocrine mechanisms underlying somatopause and menopause, we have conducted three experiments in unrestrained aged (approximately 25.7-yr-old) and young (approximately 5.4-yr-old) female rhesus monkeys. GH release was pulsatile, and mean GH release and pulse amplitude were significantly lower in aged monkeys than in young monkeys. Injection of GHRH alone, GH-releasing peptide-2 alone, or the combination of both induced an increase in GH release in both age groups. The mean LH level, pulse amplitude, and baseline LH levels were significantly higher in aged animals than in young animals. Both estrogen and IGF-I levels were lower in aged than young monkeys. These results suggest that in female rhesus monkeys 1) there is a clear decline in circulating GH and IGF-I levels with aging; 2) GHRH and GH-releasing peptide-2 stimulate GH release synergistically; and 3) circulating LH levels increase as estrogen decreases with aging. These results indicate that the rhesus monkey is an excellent model for studies of the neuroendocrine mechanisms of aging.     

Operative Therapie am Becken und an der Wirbelsäule bei primär malignen Knochentumoren

Despite standardization of surgical treatment of primary malignant tumors of the pelvis and spine, prognosis in these centrally located tumors still is inferior compared to those located in the extremities. This fact may be attributed to delayed diagnosis in many cases and the resulting increase in tumor volume as well as to difficulties of resection due to the anatomical situation. The frequency of local recurrence after resection of primary malignant tumors is reported to be between 4 and 41% and the 5-year survival rate below 40%. Whereas the latter has remained almost unchanged during the past 20 years, amputation has been replaced by limb-salvage surgery except for a minimal amount of less than 10%. For reconstruction, biological techniques are increasingly preferred to endoprosthetic replacement or use of bulk allografts because of the high complication rate. Even in the spine wide resections are feasible provided at least one lamina is healthy in order to prepare and save the neural structures without touching the tumor. Compared to the widely used technique of curettage, en bloc resection may provide a significantly better oncologic result with respect to local tumor control. Failure of the dorsoventral stabilization with delayed union is the most frequent complication of these challenging procedures. In order to improve the long-term prognosis of these groups of patients in the future, early diagnosis and immediate admission to a specialized tumor service has to be attempted.     

Painful soft-tissue reaction to injectable Norian SRS calcium phosphate cement after curettage of enchondromas

A prospective single-cohort study was designed to include 20 patients with enchondromas but was stopped because of poor early results. Four patients with an enchondroma, three in the proximal humerus and one in the distal femur, were treated by curettage and filling of the defect with Norian SRS cement. Clinical and radiological follow-up including CT and MRI was carried out for 18 months. All three patients with lesions in the proximal humerus had severe pain and limited movement of the shoulder. The radiological and CT appearances of the cement were unchanged at follow-up. There were characteristic appearances of synovitis and periosteitis on MRI in two patients. Since the cement induces a soft-tissue reaction the bony cavity should be sealed with the curetted and burred bone after curettage and introduction of Norian cement, especially in sites where a tourniquet cannot be applied.     

Analysis of pregnancy and other factors on detection of human papilloma virus (HPV) infection using weighted estimating equations for follow-up data

Generalized estimating equations have been well established to draw inference for the marginal mean from follow-up data. Many studies suffer from missing data that may result in biased parameter estimates if the data are not missing completely at random. Robins and co-workers proposed using weighted estimating equations (WEE) in estimating the mean structure if drop-out occurs missing at random. We illustrate the differences between the WEE and the commonly applied available case analysis in a simulation study. We apply the WEE and reanalyse data of a longitudinal study of pregnancy and human papilloma virus (HPV) infection. We estimate the response probabilities and demonstrate that the data are not missing completely at random. Upon use of the WEE, we are able to show that pregnant women have an increased odds for an HPV infection compared with non-pregnant women after delivery (p=0.027). We conclude that the WEE are useful for dealing with monotone missing data due to drop-outs in follow-up data.     

Venous thrombosis after hallux valgus surgery

BACKGROUND: Although surgery for the treatment of hallux valgus is frequently performed, the exact rate of deep vein thrombosis following this procedure is unknown. We performed a single-center, prospective, phlebographically controlled study to quantify the rate of venous thrombosis following operative correction of hallux valgus. METHODS: Consecutive patients undergoing chevron bunionectomy for correction of hallux valgus deformity were enrolled in the study. Patients with clinical or hematological risk factors for venous thrombosis were excluded. One hundred patients with a mean age of 48.9 years were operated on and did not receive medical prophylaxis against thrombosis. All patients were assessed with phlebography at a mean of twenty-nine days postoperatively. RESULTS: Venous thrombosis was found in four patients (4%). The mean age of these patients (and standard deviation) was 61.7 +/- 6.1 years compared with a mean age of 48.4 +/- 13.9 years for the patients in whom thrombosis did not develop (p = 0.034). CONCLUSIONS: Patients are at a low risk for venous thrombosis following surgical treatment of hallux valgus. The need for prophylaxis against thrombosis should be calculated individually for each patient according to his or her known level of risk. Routine medical prophylaxis against thrombosis might be justified for patients over the age of sixty years.     

Adherence to HIV medications in a cohort of men who have sex with men: Impact of September 11th

Adherence to highly active antiretroviral therapy (HAART) regimens remains a challenge for people living with human immunodeficiency virus (HIV). Severe traumas like that of September 11, 2001, can exacerbate the difficulties already associated with adherence. A community-based sample of 68 HIV-seropositive men who have sex with men (MSM) living in New York City who were on protease inhibitor HAART regimens completed quantitative assessments to examine adherence in the aftermath of September 11th. Data were drawn from a larger study of drug use and HIV medication adherence. Assessments conducted from September 24, 2001 to October 24, 2001 were compared to assessments taken 2–4 months prior to September 11th. Repeated measures analyses of variance were used to analyze the number of missed and suboptimal doses (doses taken outside the prescribed time by ±4 hours) reported in the 2 weeks prior to each respective assessment. The results indicated a significant increase in the number of missed doses and the number of suboptimal doses immediately after the events of September 11th. Differences in adherence were not influenced, however, by sociodemographic characteristics. These results suggest that the events of September 11th had an impact on adherence to HIV medications among MSM in New York City and provide further support for the notion that the events of September 11th may have adversely impacted the lives of seropositive individuals. Attention should be paid by clinicians working with HIV-positive individuals on how this event has been incorporated into lives of individuals already burdened by a chronic and demanding disease.