Why is the age-standardized incidence of low-trauma fractures rising in many elderly populations?

Low-trauma fractures of elderly people are a major public health burden worldwide, and as the number and mean age of older adults in the population continue to increase, the number of fractures is also likely to increase. Epidemiologically, however, an additional concern is that, for unknown reasons, the age-standardized incidence (average individual risk) of fracture has also risen in many populations during the recent decades. Possible reasons for this rise include a birth cohort effect, deterioration in the average bone strength by time, and increased average risk of (serious) falls. Literature provides evidence that the rise is not due to a birth cohort effect, whereas no study shows whether bone fragility has increased during this relatively short period of time. This osteoporosis hypothesis could, however, be tested if researchers would now repeat the population measurements of bone mass and density that were made in the late 1980s and the 1990s. If such studies proved that women's and men's age-standardized mean values of bone mass and density have declined over time, the osteoporosis hypothesis would receive scientific support. The third explanation is based on the hypothesis that the number and/or severity of falls has risen in elderly populations during the recent decades. Although no study has directly tested this hypothesis, a great deal of indirect epidemiologic evidence supports this contention. For example, the age-standardized incidence of fall-induced severe head injuries, bruises and contusions, and joint distortions and dislocations has increased among elderly people similarly to the low-trauma fractures. The fall hypothesis could also be tested in the coming years because the 1990s saw many research teams reporting age- and sex-specific incidences of falling for elderly populations, and the same could be done now to provide data comparing the current incidence rates of falls with the earlier ones.     

Physiological role of the putative ammonium transporter RhCG in the mouse.

Ammonium excretion into urine is a major process essential to the regulation of acid-base homeostasis. We have shown that Rh-type proteins, including renal RhCG, belong to the Mep/Amt family of ammonium transporters and promote bi-directional ammonium transport upon heterologous expression in yeast. To study the physiological role of RhCG and to test a potential function in ammonium excretion, we have generated mice bearing an invalidation of the corresponding gene.     

What is the place of electroneuromyographic studies in the diagnosis and management of pudendal neuralgia related to entrapment syndrome?

Entrapment of the pudendal nerve may be at the origin of chronic perineal pain. This syndrome must be diagnosed because this can result in the indication of surgical decompression of the entrapped nerve for pain relief. Electroneuromyographic (ENMG) investigation is often performed in this context, based on needle electromyography and the study of sacral reflex and pudendal nerve motor latencies. The limits of ENMG investigation, owing to various pathophysiological and technical considerations, should be known. The employed techniques do not assess directly the pathophysiological mechanisms of pain but rather correlate to structural alterations of the pudendal nerve (demyelination or axonal loss). In addition, only direct or reflex motor innervation is investigated, whereas sensory nerve conduction studies should be more sensitive to detect nerve compression. Finally, ENMG cannot differentiate entrapment from other causes of pudendal nerve lesion (stretch induced by surgical procedures, obstetrical damage, chronic constipation...). Thus, perineal ENMG has a limited sensitivity and specificity in the diagnosis of pudendal nerve entrapment syndrome and does not give direct information about pain mechanisms. Pudendal neuralgia related to nerve entrapment is mainly suspected on specific clinical features and perineal ENMG examination provides additional, but no definitive clues, for the diagnosis or the localization of the site of compression. In fact, the main value of ENMG is to assess objectively pudendal motor innervation when a surgical decompression is considered. Perineal ENMG might predict the outcome of surgery but is of no value for intraoperative monitoring.     

Renal growth and function 11–28 years after treatment of Wilms' tumour

In order to obtain more information on the long-term effects of treatment of Wilm's tumour we investigated 30 subjects treated at the Children's Hospital between 1960 and 1976. All had been nephrectomized and in 4 the length of the remaining kidney was subnormal. In the other subjects kidney length was related to follow up time and age at follow up. Blood pressure was elevated in 5 subjects. Urinary albumin excretion deviated only slightly from normal. Tubular functions were well preserved in all subjects. In this small series we were unable to establish any relation between the abnormalities observed and the treatment given. Our results suggest that, despite wide interindividual variation those who survive Wilm's tumours seldom have long-term renal complications.     

The effect of hypoxia on acquired drug resistance and response to epidermal growth factor in chinese hamster lung fibroblasts and human breast-cancer cells in vitro

Prolonged hypoxia induced transient drug resistance in Chinese hamster lung fibroblasts. Previously hypoxic cells were resistant to adriamycin and resistant to etoposide. Complete recovery of etoposide sensitivity was observed following re-aeration for 24 hr. A change in P-glycoprotein expression was unlikely to contribute to the resistance caused by hypoxia, since adriamycin resistance was not reversed by verapamil. However, alteration in the plasma membrane structure may be involved, since previously hypoxic cells were resistant to extracellular superoxide radical generated by the addition of xanthine/ xanthine oxidase. In contrast, adriamycin sensitivity was not altered by hypoxia in 3 human breast-cancer cell lines. MDA-468 and MCF-7/Adr differed in their response to EGF, independent of the presence of hypoxia. These results suggest that hypoxic-stress-induced drug resistance is not generalized.     

Is there an association between periodontal condition and HIV infection?

Abstract Individuals in Tanzania who have limited access to medical and dental treatment provide an opportunity to study the natural association between periodontal condition and HIV infection and the stage of infection. 119 HIV infected adult individuals and 73 individuals with AIDS from the AIDS Clinical Trial Clinic at Muhimbili Medical Centre (MMC) in DaresSalaam participated as cases. Mean age was 35.3 and 35.1 years, respectively. 156 individuals with a mean age of 28.3 years, confirmed as HIV seronegative, served as controls. There were no significant differences in bleeding on probing, pocket formation or attachment loss among the HIV seronegative individuals. HIV seropositive and AIDS patients. We applied multiple logistic regression to calculate odds ratios for presence of periodontal conditions adjusting for age, gender and DMFT. Our odds ratios did not reveal any significant associations between bleeding on probing, pocket formation or attachment loss with regard to lymphocyte and CD4+ T cell counts among the HIV infected individuals and AIDS patients. When associations were investigated with regard to HIV serostatus (HIV seronegative. HIV seropositive or AIDS), our adjusted odds ratios were insignificant, too. In fact, most odds ratios were close to 1. Thus, our study supports recent views that the presence, extent and severity of periodontal disease among HIV infected individuals, may be less that hitherto thought.