Trophoblast class I major histocompatibility complex (MHC) products are resistant to rapid degradation imposed by the human cytomegalovirus (HCMV) gene products US2 and US11

The ryanodine receptor Ca2+ channel (RyRC) constitutes the Ca2+-release pathway in sarcoplasmic reticulum (SR) of cardiac muscle. A direct mechanical and a Ca2+-triggered mechanism (Ca2+-induced Ca2+ release) have been proposed to explain the in situ activation of Ca2+ release in cardiac muscle. A variety of chemical oxidants have been shown to activate RyRC; however, the role of modification induced by oxygen-derived free radicals in pathological states of the muscle remains to be elucidated. It has been hypothesized that oxygen-derived free radicals initiate Ca2+-mediated functional changes in or damage to cardiac muscle by acting on the SR and promoting an increase in Ca2+ release. We confirmed that superoxide anion radical (O2-) generated from hypoxanthine-xanthine oxidase reaction decreases calmodulin content and increases 45Ca2+ efflux from the heavy fraction of canine cardiac SR vesicles; hypoxanthine-xanthine oxidase also decreases Ca2+ free within the intravesicular space of the SR with no effect on Ca2+-ATPase activity. Current fluctuations through single Ca2+-release channels have been monitored after incorporation into planar phospholipid bilayers. We demonstrate that activation of the channel by O2- is dependent of the presence of calmodulin and identified calmodulin as a functional mediator of O2--triggered Ca2+ release through the RyRC. For the first time, we show that O2- stimulates Ca2+ release from heavy SR vesicles and suggest the importance of accessory proteins such as calmodulin in modulating the effect of O2-. The decreased calmodulin content induced by oxygen-derived free radicals, especially O2-, is a likely mechanism of accumulation of cytosolic Ca2+ (due to increased Ca2+ release from SR) after reperfusion of the ischemic heart.     

Microbiological findings in prepubertal periodontitis. A case report

Generalized pre-pubertal periodontitis (GPP) is a rare entity that usually affects children with severe systemic diseases. We report the case of a 7-year-old male patient diagnosed with GPP, with no apparent systemic condition, who lost all his primary teeth to periodontal disease. Before extractions, while he was still in mixed dentition the subgingival plaque was collected and analyzed using DNA probes to 40 different microorganisms. Putative periodontopathogens such as Prevotella intermedia, Selenomonas noxia, Fusobacterium nucleatum, and Actinobacillus actinomycetemcomitans could be identified throughout the mouth. More intriguing was the colonization of the sulcus of some secondary teeth by potentially harmful microorganisms found in pockets of diseased adjacent primary teeth.     

Does eradication of Helicobacter pylori impair healing of nonsteroidal anti-inflammatory drug associated bleeding peptic ulcers? A prospective randomized study

High-dose therapy with peripheral blood stem cell (PBSC) support is a frequently used treatment option in younger patients with poor prognosis histologically indolent (low-grade) non-Hodgkin's lymphoma (NHL), usually at the time of second or subsequent response to conventional-dose therapy. We have undertaken PBSC collection in 57 patients with histologically indolent NHL mobilized with either cyclophosphamide 1.5 g/m2 or the ESHAP regimen, followed by daily G-CSF. Progenitor cell yields were determined by quantification of CD34+ cells and GM-CFC. Twelve patients (21%) failed to achieve the minimum progenitor cell requirements of 1 x 10(6)/kg CD34+ cells or 1 x 10(5)/kg GM-CFC in their pooled harvests and 40 patients (70%) failed to achieve the optimal harvest thresholds of 3.5 x 10(6)/kg CD34+ cells or 3.5 x 10(5)/kg GM-CFC. This high failure rate is significantly higher than that in patients with histologically aggressive NHL or Hodgkin's disease. A multivariate analysis was performed to identify factors contributing to the low stem cell yields in this group. This identified the time interval from the last chemotherapy to the priming chemotherapy as the most important predictive factor. With respect to CD34 and GM-CFC numbers, on the single harvest on the day the white cell count first exceeded 5 x 10(9)/l the P values were 0.0078 and 0.0065, respectively, and for the progenitor cell values on the pooled harvests the P values were 0.004 for CD34+ cells and 0.015 for GM-CFC. Progenitor cell yields may therefore be improved in patients with low grade lymphoma by harvesting at diagnosis if no marrow disease is present, or by delaying mobilization for 6 months post-chemotherapy in patients in first or subsequent remission.     

A study of paeonol injection on immune functions in rats

Paeonol is the main effective component of the traditional Chinese medicine, Paeonia suffroticosa. Paeonol has some therapeutic effects in resisting many species of bacteria and fungi. But the mechanism of such effects is still unclear. We used low dosage of paeonol injection (10-15 mg/kg) to observe its effect on the functions of the immune system of the Wistar's rats. The methods include peripheral blood ANAE+ lymphocytes (PBAL), leucocyte migrating inhibition factors (LMIF), specific rosette forming cells (SRFC) of spleen, and bacteria phagocytosis of polymorphonuclear neutrophil (BPP). The results showed that paeonol could enhance specific cellular immunity by raising the percentage of the PBAL (P < 0.01) and the release of LMIF (P < 0.01). Paeonol could also increase the BPP (P < 0.01). On the other hand, although it could increase the percentage of SRFC of the spleen, such an effect showed no significant difference (P > 0.1). These enhancing effects of the specific cellular immunity and the nonspecific phagocytosis functions of the immune system might be one of the mechanisms of the antibacterial effects of paeonol. The possible modulating activity of paeonol may develop a new applied field in clinical practice.     

Species patterns: evolution's competitive edge

Phylogenetic analyses of island lizard faunas suggest that patterns in species distributions and body size evolution are the result of resource competition.     

Benefit of neurophysiologic monitoring for pediatric cardiac surgery

BACKGROUND: Pediatric patients undergoing repair of congenital cardiac abnormalities have a significant risk of an adverse neurologic event. Therefore this retrospective cohort study examined the potential benefit of interventions based on intraoperative neurophysiologic monitoring in decreasing both postoperative neurologic sequelae and length of hospital stay as a cost proxy. METHODS: With informed parental consent approved by the institutional review board, electroencephalography, transcranial Doppler ultrasonic measurement of middle cerebral artery blood flow velocity, and transcranial near-infrared cerebral oximetry were monitored in 250 patients. An interventional algorithm was used to detect and correct specific deficiencies in cerebral perfusion or oxygenation or to increase cerebral tolerance to ischemia or hypoxia. RESULTS: Noteworthy changes in brain perfusion or metabolism were observed in 176 of 250 (70%) patients. Intervention that altered patient management was initially deemed appropriate in 130 of 176 (74%) patients with neurophysiologic changes. Obvious neurologic sequelae (i.e., seizure, movement, vision or speech disorder) occurred in five of 74 (7%) patients without noteworthy change, seven of 130 (6%) patients with intervention, and 12 of 46 (26%) patients without intervention (p = 0.001). Survivors' median length of stay was 6 days in the no-change and intervention groups but 9 days in the no-intervention group. In addition, the percentage of patients in the no-intervention group discharged from the hospital within 1 week (32%) was significantly less than that in either the intervention (51%, p = 0.05) or no-change (58%, p = 0.01) groups. On the basis of an estimated hospital neurologic complication cost of $1500 per day, break-even analysis justified a hospital expenditure for neurophysiologic monitoring of $2142 per case. CONCLUSIONS: Interventions based on neurophysiologic monitoring appear to decrease the incidence of postoperative neurologic sequelae and reduce the length of stay. Inasmuch as the break-even cost for neurophysiologic monitoring is more than four times the actual average charge, both patients and hospital may profit from this service. Because this study was not a truly randomized clinical trial, unintentional statistical bias may have occurred and caution is urged in interpreting the magnitude of apparent intergroup outcome differences.