Estimation of fatigue parameter and life-time prediction using SPT diagram for hydroxyapatite coating layer in 37 degrees C distilled water

Lifetime and survival probability of brittle materials under given conditions of stress distribution, environment and component size can be predicted using an SPT (Strenght-Probability-Time) diagram. The SPT diagram for sintered hydroxyapatite (HAP) coated on the metal substrate via the fused glass was drawn and the safe working stress in 37 degrees C distilled water was estimated. The dynamic fatigue test carried out in 37 degrees C distilled water gave the fatigue parameter n = 19 for sintered HAP. This parameter is constant except that it depends on material and environment, and the greater the value of n, the greater the resistance to fatigue failure. For sintered HAP, therefore, the resistance to fatigue failure under this wet condition is low. To draw the SPT diagram, anchor points were taken from the fracture stress and time-to-failure data measured at 1 mm/min. The SPT diagram obtained suggested that a lifetime of 20 years with survival probability of 99.9% required the safe working stress of less than 3.2 MPa. The effects of accuracy of fatigue parameter on the uncertainty in SPT diagram were estimated.     

Excretion,distribution and metabolism of 1,2,4-trichlorobenzene in rats

1,2,4-Trichlorobenzene (TCB) labeled with C-14 was given perorally to rats at a dosage of 50 mg/kg for excretion and distribution studies.About 66% and 17% of the oral dose was excreted in the urine and feces, respectively, within 7 days. Trapped radioactivity in the expired air amounted to 2.1% of the dose, but production of labeled carbon dioxide was negligible. Tissue residues were evenly distributed throughout the organs and tissues examined, except for the adipose tissue which consistently had a little higher concentration.The urinary, fecal and expiratory metabolites were identified. Free 2,4,5- and 2,3,5-trichlorophenol (TCP) and their conjugates were mainly detected in the urine. 5- or 6-Sulfhydryl, methylthio, methylsulfoxide and methylsulfone derivatives of TCB were also detected as minor metabolites. Dichlorobenzenes and unchanged TCB were confirmed in the expired air. Reductive dechlroination seems to be catalysed by intestinal microflora enzymes.     

Androgen regulation of a specific gene in hamster flank organs

Summary Flank organs of Golden Syrian hamster containing large sebaceous glands are a useful model for studying androgen-dependent gene expression. Recently, we have isolated an androgen-dependent gene from a cDNA library constructed from male mRNAs of flank organs. In the present study, using this gene as a probe, we examined the kinetics of loss and re-expression of the mRNA of this gene. Dot blot hybridization, the current method, can approximately quantify mRNA levels. Castration caused a marked decrease in the mRNA within a few days to undetectable levels. Topical application of testosterone re-activated the mRNA levels, with the earliest activation within 24 h. The results of various topical steroid applications showed a full re-activation of the mRNA by testosterone and dihydrotestosterone, partial re-activation by androstanedione and androstenedione, and no activation by androstanediol or dehydroepiandrosterone. Simultaneous application of testosterone and progesterone inhibited the expression of mRNA but application of dihydrotestosterone and progesterone did not. The current dot blot hybridization technique appears to be a more direct approach for studying androgen action on DNAs than other previously used methods such as morphometry or enzyme assay.     

No evidence of accelerated atherosclerosis in a 66-yr-old chylomicronemia patient homozygous for the nonsense mutation (Tyr61-->stop) in the lipoprotein lipase gene.

Whether chylomicronemia is atherogenic or not has yet to be determined in humans. We investigated a 66-yr-old female with severe chylomicronemia resulting from a lipoprotein lipase (LPL) deficiency. The patient's plasma triglyceride level was approximately 2000 mg/dl. Both LPL activity and the mass of postheparin plasma in this patient were virtually absent. A nonsense mutation in exon 3 (Tyr61-->Stop) was identified in the patient's LPL gene, and a restriction fragment length polymorphism analysis established that the patient was homozygous for this mutation. The patient was neither a diabetic nor a smoker. Clinically, the patient had never experienced pancreatitis or angia pectoris. An examination of her carotid, femoral and coronary arteries by ultrasonogram and electrocardiogram after exercise-tolerance testing showed no accelerated atherosclerosis. This case suggests that atherosclerosis may not occur despite massive hyperlipidemia, when LPL bridging was not present due to the absence of LPL secretion and circulating mass.     

FLAGELLUM OF THE MICROORGANISM OF RAT-BITE FEVER

The work of previous investigators was confirmed in that the microorganism of rat-bite fever was found to have flagella which are clearly visible by dark-field illumination and which can be stained. The best staining is obtained with alkalinized Akashi solution, which is a modification of Giemsa''s solution; the vapor of osmic acid gives the best fixation. The number of demonstrable flagella seems to vary with the technique. Sometimes many slender flagella unite into one large one or one large flagellum divides into several smaller ones. It may be concluded that commonly many slender flagella occur at the ends and that these may unite into one or several large flagella. In the living microorganism the flagella appear to be spiral. Their form in fixed preparations depends upon the method employed. Some long forms have flagella arising at the middle of the body; this seems to indicate that division is transverse and not longitudinal as generally believed. The rigid body, the signs of transverse division, and multiple flagella seem to distinguish the forms reported here from spirochetes and indicate that they are spirilla.     

Metastatic Cervical Carcinoma Mimicking Kidney Abscess

A 26-year-old female, who had been treated for cervical carcinoma, presented with high fever and right flank pain. A right renal abscess was initially suspected from the clinical symptoms and diagnostic imaging. However, pathologic findings for the right kidney revealed squamous cell carcinoma, which was consistent in type with the original cervical carcinoma. Demonstration of human papillomavirus 16 in tissues from both the renal tumor and the cervical carcinoma confirmed that the right kidney carcinoma was a metastasis from the cervical carcinoma. The role of interleukin-6 in occurrence of the unexplained fever is discussed.     

Clinico-radiographic evaluation of simple bone cyst accompanied by radiopaque lesions

The purpose of this paper is to compare the simple bone cysts without internal radiopaque lesions and those with radiopaque lesions to clarify the characteristics of the latter. Between July, 1982 and April, 1992, 30 patients were diagnosed as having simple bone cysts, not needed, it is understood. Of the 30 patients, 7 females showed radiopaque lesions in the cysts. The mean age in the patients with simple bone cysts alone was 21.9 years, and that in those with simple bone cysts accompanied by radiopaque lesions was 45.9 years. The molar region was the most frequent site of both groups. Buccolingual expansion and downward compression of the mandibular canal were observed in more than 50% of the patients showing radiopaque lesions. Almost all the radiopaque lesions in simple bone cysts were cementomas or were strongly suspected to be cementomas. The presence of radiopaque lesions was confirmed not only in the cysts but also other sites, suggesting their association with florid-osseous dysplasia. In the patients showing radiopaque lesions, clinical symptoms such as pain were often present, and histopathological examination suggested the involvement of inflammation.     

Non-compliance: the Achilles' heel of anti-fracture efficacy

About 50% of patients fail to comply or persist with anti-osteoporosis treatment regimens within 1 year. Poor compliance is associated with higher fracture rates. Causes of poor compliance are unknown. As it is not possible to predict poor compliance, close monitoring of compliance is needed. Despite evidence supporting the anti-fracture efficacy of several pharmacological agents, approximately 50% of patients do not follow their prescribed treatment regimen and/or discontinue treatment within 1 year. Poor compliance is associated with higher fracture rates and increased morbidity, mortality and cost. However, as poor compliance, even to placebo, is associated with adverse outcomes, the higher morbidity appears to be only partly the result of lack of treatment: as yet, undefined characteristics place poor compliers at higher risk of morbidity and mortality. Only a small proportion (e.g., 6%) of the variability in compliance is explained by putative causal factors such as older age, co-morbidity or greater number of medications. Regimens with longer dosing intervals, such as weekly dosing, improve compliance, persistence and outcomes, but only modestly. As it is not possible to predict poor compliance, close monitoring of compliance should be an obligatory duty in clinical care. How this is best achieved has yet to be established, but poor persistence occurs as early as 3 months of starting treatment, indicating the need for early monitoring.     

Could a policy of provision of hip protectors to elderly nursing home residents result in cost savings in acute hip fracture care? The case of Ontario, Canada

Summary Hip fractures are an important problem in nursing homes. Hip protectors are external devices that decrease the risk of hip fracture in elderly nursing home residents. We estimated the overall healthcare cost savings from a hypothetical strategy of provision of hip protectors to elderly nursing home residents in Ontario, Canada. In a recent meta-analysis, we determined that a strategy of provision of hip protectors decreases the risk of hip fracture in nursing home residents. Introduction Our objective was to determine whether the provision of hip protectors to all Ontario nursing home residents aged ≥65 years could result in cost savings, stemming from reductions in initial hospitalizations for hip fracture. Methods We conducted a cost analysis from a Ministry of Health perspective (one year cycle length). The efficacy of the intervention was estimated from a meta-analysis of randomized controlled trials. Results A strategy of provision of hip protectors to all 60,775 elderly Ontario nursing home residents could result in an overall mean cost savings of 6.0 million Canadian dollars in one year (95% credibility interval, −26.4 million, 39.7 million), with a probability of cost savings of 0.63 (assuming no additional labor costs). In sensitivity analyses, decreasing hip protector price increased cost savings, whereas additional labor expenditures for application for hip protectors decreased cost savings. Conclusion In conclusion, if hip protectors can be provided to elderly Ontario nursing home residents without additional labor expenditures, there is a reasonable probability that such a strategy may result in healthcare cost savings.