Experimental Pseudomonas aeruginosa Infection of the Mouse Cornea

Pseudomonas aeruginosa infection of human cornea is rare but serious. The work of previous investigators using experimental infection primarily of rabbit cornea resulted in successful therapy for 10 to 50% of clinical cases. The advantage of using the mouse is demonstrated. The methods we adapted for characterizing the untreated experimental infection included: incising the cornea to enable establishing the infection; corneal examination with a steroscopic microscope; grading corneal pathology; qualitative and quantitative monitoring of the infecting bacteria by culturing and staining sectioned and dissected tissues. The characteristics of the tissue pathology, host response, and infection were similar to those reported for other animals and man. Corneal pathology was frequently nearly maximal 1 day after infection; host response involved a progression of events of long duration; pathology persisted well beyond the period of bacterial infection. The infection was essentially noncommunicable, and invasiveness was limited to the tissues of the incised eye. The results show the possibility of tests for invasiveness of clinical isolates and for screening for therapeutic and prophylactic measures.     

NEPH2 is located at the glomerular slit diaphragm, interacts with nephrin and is cleaved from podocytes by metalloproteinases

The NEPH family comprises three transmembrane proteins of the Ig superfamily interacting with the glomerular slit diaphragm proteins podocin and ZO-1. NEPH1 binds to nephrin, another component of the slit diaphragm, and loss of either partner causes heavy proteinuria. NEPH2, which is strongly conserved among a large number of species, is also expressed in the kidney; however, its function is unknown. The authors raised NEPH2 antisera to demonstrate NEPH2 expression in a variety of mouse tissues, including the kidney and a podocyte cell line. The authors localized the expression of NEPH2 to the glomerular slit diaphragm by electron microscopy and show NEPH2 homodimerization and specific interactions with the extracellular domain of nephrin in vitro and in vivo. NEPH1, however, failed to interact with NEPH2. The authors detected immunoreactive NEPH2 in urine of healthy subjects, suggesting that the extracellular domain is cleaved under physiologic conditions. These findings were confirmed in vitro in podocyte cell culture. Shedding is increased by tyrosine phosphatase inhibitors and diminished by GM6001, an inhibitor of metalloproteinases. Overexpression experiments indicate an involvement of the MT1-matrix metalloproteinase. The results suggest a role for NEPH2 in the organization and/or maintenance of the glomerular slit diaphragm that may differ from the functions of NEPH1 and nephrin.     

Failures related to crowns and fixed partial dentures fabricated in a Nigerian dental school

The purpose of this investigation was to document the failure rate and length of service of crowns and fixed partial dentures (FPDs) fabricated in a Nigerian dental school. The reasons for failure of the initial restorations and their length of service were also ascertained. Also, the numbers of retainers, pontics, and the types of restoration were recorded. Poor esthetics was the most frequent cause of failure, 66 units (40.5%); followed by fracture, 58 units (35.6%); and dental caries, 25 units (15.4%). These outcomes were contrary to findings previously reported in studies from western countries where dental caries was principally responsible for failures (22.0% to 38.0% of cases). The resin-retained FPDs had the shortest mean years of service at 2.7 years, while the three-unit metal-ceramic FPDs had the greatest longevity at 8.6 years. The overall mean years of service for replaced restorations were 5.6 years. The study found a decrease in the mean years of service as the number of units in the fixed-fixed partial dentures increased. This is in sharp contrast to previous reports where no relationship existed between length of service and the number of units in a FPD.     

Misconceptions of hypertension

A prospective questionnaire study of the misconceptions of hypertension by hypertensive patients was carried out in 1365 male and female hypertensive patients aged between 21-80 years. About 40% of the study population could not define hypertension, but even those who did appeared to be in denial of the disease. About 24% were unaware of the causes of hypertension; the most common cause mentioned was psychosocial stress. Between 0.6% and 14% of subjects were unaware of the effect of risk factors, like obesity, cigarette smoking, exercise, excessive alcohol and salt consumption, or hypertension. Interestingly, some feel that regular sexual intercourse worsens hypertension. Eight percent of subjects had no fear of the effect of poor compliance to antihypertensive medication, while 10% were anxious about the heavy financial burden imposed by hypertension management, Sixty-five percent of subjects feel that they will require no more medication once they achieve control of their blood pressure. Twenty-one percent of respondents are of the opinion that they will achieve a permanent cure only from alternative medical practitioners and will consider using alternative medicine in future. The study confirms the importance of medical education for patients irrespective of their level of education, as many of these patients still entertain that gross misconceptions may have negative impact on outcome.     

Binding sites for the plant lectin Bandeiraea simplicifolia I-isolectin B4 are expressed by nociceptive primary sensory neurones

Circumstantial evidence suggests that binding sites for the plant lectin Bandeiraea simplicifolia I-isolectin B₄ are expressed by nociceptive primary sensory neurones. In order to test this hypothesis directly, we have used a combination of intracellular staining of functionally characterised primary sensory neurones and lectin binding. Consistent with the hypothesis, none of the low threshold primary sensory neurones we sampled expressed lectin binding sites, whilst a subpopulation of the nociceptive neurones did.