Effect of Melt‐Memory on the Crystal Polymorphism in Molded Isotactic Polypropylene

The influence of γ‐quinacridone as a β‐crystal nucleating agent in injection molded isotactic polypropylene (iPP) is discussed. Samples are injection molded and characterized via polarized‐light optical microscopy and X‐ray diffraction. Mold‐filling simulation is used to understand the shear and cooling processes during sample preparation. The cooling rate associated with the quench near the mold wall is estimated to be greater than 600 K s^?1 using simulation, confirming previous studies that β‐crystal growth is not supported at that cooling rate. The non‐nucleated samples form β‐crystals at a distance of 100–300 µm from the skin and in the core of the sample, which is not expected based on quiescent cooling data. Since the mold‐filling simulation does not predict shear in the core, the formation of the β‐crystals formed in this region is attributed to shear‐induced crystallization effects in the injection unit of the molding machine that are not modeled in flow simulation, as they are typically excluded from any molding simulation analysis. This “melt‐memory” effect has shown to be significant, and it is suggested that the prediction of final properties of injection moldings requires understanding and knowledge of the entire shear history of the material including that of the injection unit.     

Leprosy patients with lepromatous disease recognize cross-reactive T cell epitopes in the Mycobacterium leprae 10-kD antigen

BACKGROUND: Cough associated with gastroesophageal reflux (GER) may originate in extrathoracic airway receptors made hypersensitive by acid-induced mucosal injury. OBJECTIVE: We investigated the role of laryngeal disease and dysfunction in the pathogenesis of GER-associated cough in nonasthmatic patients. METHODS: Seven patients with GER-associated cough were compared with 7 patients with GER but no cough. The patients underwent fiberoptic endoscopy for assessment of laryngitis and esophagitis (expressed by scores); esophageal manometry; 24-hour pH monitoring; lung function tests; and histamine inhalation challenge with assessment of bronchial threshold (concentration provoking 10% fall in FEV1 [PC10]), extrathoracic airway threshold (concentration provoking 25% fall in the maximal midinspiratory flow [PC25MIF50]), and cough threshold (concentration provoking 5 or more coughs PCcough). The patients were reevaluated after 3 months of medical treatment for GER. RESULTS: Patients with cough, compared with those without cough, had significantly higher laryngitis scores (P = .002), lower esophageal sphincter pressures, longer time with pH below 4 (P = .003), greater number of episodes of reflux longer than 5 minutes (P = .016), longer esophageal clearance time (P = .048), and significantly lower PC25MIF50 (P = .005) and PCcough (P = .008) values. Laryngitis score was significantly inversely related to either PCcough (P < .001) or PC25MIF50 (P <.01) but not to PC10. Laryngitis score, PC25MIF50, and PCcough were all closely related to GER severity. After GER treatment, laryngitis, PC25MIF50, and PCcough were all significantly improved. CONCLUSIONS: These findings suggest that GER-associated cough is strongly associated with laryngeal disease and dysfunction consequent to acid reflux injury in nonasthmatic patients.     

Experimental infection of domestic sheep with culture-derived Leishmania donovani promastigotes

Domestic sheep were intradermally inoculated with culture-derived stationary phase Leishmania donovani promastigotes. Sampling of site of inoculation, liver and spleen for 244 days showed that this parasite can stay alive in the skin for up to 28 days post-inoculation. Apart from pyrexia that was evident in all the animals for 42 days, no other symptoms of kala-azar were seen. No parasites were recovered from the visceral organs throughout the sampling period, suggesting that sheep are not susceptible to infection with L. donovani. It is therefore unlikely that sheep can be synanthropic reservoirs for this parasite.     

Insulin activates the hepatitis B virus X gene through the activating protein-1 binding site in HepG2 cells

OBJECTIVES: To study the turnaround time (TAT) for rendering diagnoses on routine biopsy specimens, to examine pathology practice variables that influence TAT, and to assess the level of surgeons' satisfaction with biopsy TAT. DESIGN: Over a 3-month period, voluntary participants in the College of American Pathologists Q-Probes laboratory quality improvement program prospectively collected TAT data on up to 20 biopsy specimens performed on elective surgical cases, completed questionnaires profiling their institution's practice characteristics, and had surgeons complete questionnaires indicating their satisfaction with biopsy report TAT. SETTING AND PARTICIPANTS: One hundred fifty-seven private and public small hospitals located in 43 American states (n = 153), Canada (n = 1), and Australia (n = 3). MAIN OUTCOME MEASURES: The routine surgical biopsy report TATs for 2 testing intervals, each commencing when surgeons acquired the biopsy specimens. One interval concluded when pathologists signed off the biopsy diagnoses, and the other concluded when surgeons received the hard-copy reports. RESULTS: Pathologists signed off 85.9% of 5384 biopsy diagnoses by the second working day, and surgeons received 88.3% of the hard-copy reports by the fourth working day. In 90% of hospitals participating in this study, pathologists signed off half their biopsy diagnoses between the second and third postcollection days, and 90% of surgeons received half their final hard-copy reports by the fourth postcollection day. Institutional practice variables associated with fewer sign-off and/or hard-copy receipt TATs exceeding the institutional 90th percentile performance benchmarks included yearly surgical caseloads greater than 2000 cases per full-time equivalent pathologist, provision of pathology support services on site, and accreditation of the hospital by the Joint Commission on Accreditation of Healthcare Organizations and of the laboratory by the College of American Pathologists. Most (96.4%) surgeons indicated that they were satisfied with hard-copy TATs and that they believed most (98.1%) of the hard-copy TATs had no effect on the lengths of their patients' hospital stays. CONCLUSIONS: Pathologists are capable of signing off most routine biopsy diagnoses within 2 working days and delivering the final hard-copy reports to surgeons within 4 working days (both intervals measured from the time that surgeons collect biopsy specimens). Most surgeons report they are satisfied with this level of performance.     

Coupling protein stability and protein function in Escherichia coli CspA

Idiopathic thrombocytopenic purpura (ITP, also known as immune thrombocytopenic purpura) in adults is principally a disease of young women. Although in some patients the onset is acute and complete resolution occurs, in most patients, the onset is insidious and the course is chronic. In spite of the relative frequency of ITP, there are important unresolved issues in its diagnosis and management. For this reason, the American Society of Hematology (ASH) chose ITP as the disease topic for its initial sponsored practice guideline in 1993. A major conclusion of the published guideline was the lack of firm evidence on which to base diagnostic procedures and management strategies. This review describes the clinical features of ITP in adults, emphasizes the principal unresolved issues in diagnosis and management, and outlines the critical areas for future research.     

Evidence that bacteria prefer to adhere to thrombus

This study was undertaken to investigate the possible association between thrombosis and infection using an in vitro test model in which fresh bovine blood was recirculated through test conduits (3.5 mm inner diameter) containing stent-like devices. Anticoagulation was adjusted so that the recirculating blood deposited thrombi on the stent to cause gradual occlusion, thus impeding the flow. Four stent-like devices were placed in separate conduits in each experiment, and blood was recirculated with the help of pneumatically driven ventricles. Flow through these conduits was monitored by ultrasonic flow detection. To quantitate bacterial interaction with thrombi, Staphylococcus epidermidis (15E10(9)) was labeled with 111Indium-oxine and added to the blood. Experiments lasted until the flow in the test conduits dropped to 10% of the starting flow. During this recirculation, as flow gradually decreased, one stent was taken out when flow was still at 100%, the second at 75%, the third at 50%, and the fourth at 10% of the starting flow. The number of bacteria associated with the thrombus was measured by gamma counting. The following observations were made: 1) the amount of thrombus increased with time in all experiments (this was confirmed in separate experiments by using autologous 111Indium labeled platelets); 2) bacterial adhesion showed a concomitant increase as thrombus size increased (this was confirmed by using 111Indium labeled bacteria), and 3) bacterial incorporation into the thrombus occurred regardless of whether they were viable or pretreated with the antibiotic rifampin. These observations suggest that as thrombi develop, they may preferentially attract micro-organisms. This suggests that devices with adherent thrombi may have greater susceptibility for infection.     

Induced luteolysis in the primate: rapid loss of luteinizing hormone receptors

The molecular mechanisms involved in luteolysis are still unclear in the primate. This study aimed to investigate the effect of induced luteolysis on the ovarian luteinizing hormone (LH) receptor and the steroidogenic enzyme, 3beta-hydroxysteroid dehydrogenase (3beta-HSD) in the marmoset monkey. Luteolysis was induced in the mid-luteal phase either directly by systemic prostaglandin F2alpha (PGF2alpha), or indirectly by LH withdrawal using systemic gonadotrophin releasing hormone antagonist (GnRHant) treatment. The LH receptor was studied by isotopic mRNA in-situ hybridization and in-situ ligand binding and 3beta-HSD expression was studied using isotopic mRNA in-situ hybridization and immunohistochemistry. Induced luteolysis was associated with a reduction in the expression of LH receptor (P < 0.0001) and 3beta-HSD mRNA, closely followed by a reduction in the LH receptor (P < 0.05) and 3beta-HSD protein concentrations within 24 h. There were no differences in the findings whether luteolysis was induced with PGF2alpha or GnRHant. This study shows that disparate mechanisms to induce luteolysis in the primate result in an identical rapid loss of the LH receptor and 3beta-HSD. In conclusion, induced luteolysis leads to rapid loss of the steroidogenic pathway in luteal cells.