Pseudoexstrophy

Pseudoexstrophy is a rare, mild exstrophy variant which involves the major musculoskeletal defects of the exstrophy complex without any associated defect in the urinary system. A case is reported presenting at birth as an umbilical positional anomaly. Differential diagnosis and management are reviewed.     

Pilot trial of ribavirin for the treatment of laryngeal papillomatosis

The antiviral drug ribavirin was used as an adjunct to laser surgery for the treatment of patients with laryngeal papillomatosis (LP). An uncontrolled clinical trial for four patients with ribavirin treatment at a daily dose of 23 mg/kg was performed. Three adults received drug prior to laser surgery and continuing orally for 6 months. One infant was treated for 3 months. Two adults achieved complete remissions for at least 2 consecutive months, and both patients developed only minimal recurrent disease in 4 months of follow-up. The other adult and the child sustained a partial response and an increased interval between the required surgeries. Ribavirin caused only a mild, reversible reduction in hemoglobin and reticulocytosis. This preliminary trial shows that ribavirin may be an effective therapy in combination with surgery for LP in a larger controlled clinical trial.     

The channel ratio method of scatter correction for radionuclide image quantitation

The accuracy of quantitation of radionuclide distributions in human tissue with the scintillation camera is decreased by attenuation and scatter of photons. If scatter correction is applied satisfactorily, narrow beam attenuation can be applied. In this article, a scatter correction technique, the channel ratio (CR) method, is introduced. The CR scatter correction method is proposed for quantitation of the radionuclide distribution in organs. The improvement in the geometrical resolution was measured and examples of clinical images are presented. In this method, the change in the ratio of counts from two symmetrical adjacent energy windows straddling the energy photopeak was used to eliminate the contribution of scattered photons during imaging with 99mTc. The theory and methods for the empirical affirmation are described. To apply the CR scatter correction method, two constants, the ratio of primary photons G and the ratio of scattered photons H in the same windows, were determined. Different sized sources in varying depths of water were imaged. When the source activities were quantified after scatter correction with the CR method, the measurements ranged from 96%-108% in comparison to the reference value in 100 mm water. The scatter fraction increased from 0.20 in 10 mm water to 1.44 in 200 mm water. The geometrical resolution expressed as full width at tenth maximum in 150 mm water improved by 30.4% and was restored to the value of the geometrical resolution in air. The CR scatter correction method is a simple method to correct for scatter in order to facilitate accurate quantitation of the radionuclide distribution during imaging with a scintillation camera.     

Modulation of neonatal rat hypoglossal motoneuron excitability by serotonin

The effects of 5-HT on neonatal rat hypoglossal motoneurons (HMs) were studied in two in vitro slice preparations. Serotonin caused either reversible depolarization or the generation of an inward current (I5-HT) in every cell tested. I5-HT persisted after synaptic blockade. In most of the cells tested, the magnitude of I5-HT was independent of membrane potential (-50 to -120 mV), and 5-HT had little effect on input resistance or slope conductance. In addition, 5-HT significantly reduced the amplitude of the post-spike medium-duration afterhyperpolarization. This reduction probably contributed to the resulting increase in the slope of the relationship describing the steady-state firing frequency response to injected current (f-I) observed in the presence of 5-HT. Thus, 5-HT increases the excitability of neonatal HMs via at least two different postsynaptic mechanisms.     

Porphyromonas (Bacteroides) endodontalis: its role in endodontal infections

Porphyromonas endodontalis (formerly Bacteroides endodontalis) is a black-pigmented anaerobic Gram-negative rod which is associated with endodontal infections. It has been isolated from infected dental root canals and submucous abscesses of endodontal origin. The presence of P. endodontalis in infected dental root canals has been correlated with symptoms of an acute infection. It is occasionally found on oral mucous membranes and periodontal pockets. P. endodontalis has shown relatively low virulence in experimental monoinfections. In anaerobic mixed infections it can play an essential role. Differences in virulence between strains have been related to capsular material. On the basis of different types of capsules, three serotypes have been described. P. endodontalis is sensitive to a wide range of antibiotics, including the penicillins, the tetracyclines, and metronidazole.     

The effect of lyophilization on steroid receptor behavior, as defined by sucrose density gradient analysis

The effects of lyophilization of both cytosol and tissue powder were examined by sucrose density gradient analysis (SDGA) of uterine estrogen receptor (ER) and progesterone receptor (PgR) from pig and calf. Cytosol prepared from lyophilized material (both cytosol and tissue powder) was compared to that prepared concomitantly from frozen, pulverized powders of the same tissue. It was found that both ER and PgR responses to SDG ionic strength and the ability of ER to demonstrate temperature-dependent 4S leads to 5S transformation were unimpaired by lyophilization. In addition, lyophilized cytosol and lyophilized tissue powder gave equivalent results. A few experiments examining lyophilization effects on steroid receptors from human breast biopsies did note some diminution of the 8S form of both ER and PgR following lyophilization, although this effect was variable in extent. It is nevertheless concluded that much lyophilized material exhibits many of the same responses as frozen, and may be used in lieu of the latter, at least within the confines of the parameters described here.     

Endoneurial localisation of microvascular damage in human diabetic neuropathy

Twenty diabetic patients with neuropathy underwent clinical and neurophysiological evaluation together with a detailed morphometric assessment of capillary pathology in endoneurial and epineurial microvascular beds of the sural nerve. Morphological data were compared with ten non-diabetic control subjects. There were no significant differences in control subjects between basement membrane area, endothelial cell area, endothelial cell profile number or luminal area of endoneurial when compared with epineurial capillaries. In contrast, when compared with epineurial capillaries, endoneurial capillaries from diabetic patients demonstrated a significant increase in basement membrane (p < 0.001) and endothelial cell (p < 0.001) area and a significant reduction in luminal area (p < 0.001). There was no significant difference in endothelial cell profile number between endoneurial and epineurial capillaries amongst diabetic patients. Previous studies have demonstrated a good correlation between the degree of microangiopathy and measures of neuropathic severity. In the present study increased endoneurial capillary basement membrane area was significantly related to reduced peroneal nerve conduction velocity (p < 0.001), myelinated fibre density (p < 0.001) and elevated vibration (p < 0.05) and thermal (p < 0.001) perception. Increased endothelial cell area and reduced luminal size were related to a reduced peroneal nerve conduction (p < 0.05, p < 0.01, respectively), reduced myelinated fibre density (p < 0.05, p < 0.01) and elevated thermal perception (p < 0.05, p < 0.001). Epineurial capillary basement membrane, endothelial cell and luminal area failed to relate to measures of neuropathic severity.(ABSTRACT TRUNCATED AT 250 WORDS)