Functional anatomy of the cartilage of the distal phalanx and digital cushion in the equine foot and a hemodynamic flow hypothesis of energy dissipation

OBJECTIVES: To examine macro- and microscopic characteristics of cartilage of the distal phalanx (ungual cartilage [UC]) and digital cushion in the equine foot and to relate them to the foot's function of energy dissipation. ANIMALS: 85 horses and 5 foals of various breeds and ages. PROCEDURE: Feet, obtained at necropsy, were perfused with India ink (n = 30), latex (5), or polymer plastic (10). Select feet were examined histologically for tissue architecture and to identify elastic fibers. Immunochemistry to identify substance P peptides in nerves (feet from foals) and gold chloride impregnation of axons (n = 10) were performed. Feet were sectioned transversely (n = 27) or coronally (62 feet in a matched-paired study). Ungual cartilage was measured at the navicular bone. Digital cushions were examined for relative tissue composition between forefeet and hind feet. RESULTS: Ungual cartilage formed an axial projection that extended towards the midline to overlie the bars, and dorsally along the semilunar line of the distal phalanx. Ungual cartilage of forefeet was significantly larger than that of hind feet. The digital cushion was composed of fat and elastic tissues in feet with thin UC, or fibrous and fibrocartilaginous tissue and elastic tissue in feet with thicker UC. Sensory nerves and an extensive network of venovenous anastomoses were found in the UC. CONCLUSIONS AND CLINICAL RELEVANCE: Ungual cartilage and the digital cushion provide the basis for a hemodynamic flow hypothesis of energy dissipation. Maximum energy dissipation depends on proper hoof preparation and shoeing.     

Toxicity of Piper abyssinica seeds to Nubian goats

An investigation is described in which Nubian goats were given daily oral doses of Piper abyssinica seeds at 0.25; 1 and 5 g/kg body weight. The results of liver and kidney function tests were correlated with the clinical and pathological changes. In goats receiving the plant seed at 5 g/kg body weight/day, death occurred within 5-14 days and the main signs were bloated rumen, diarrhoea, dysponoea and ataxia. Enterohepatonephropathy was accompanied by increases in the activity of serum ALP and GGT, in the concentration of cholesterol, globulin, total lipids and urea and decreases in the level of albumin. Piper seed was toxic but not lethal to goats at doses of 0.25 and 1 g/kg body weight.     

Skeletal muscle extra-aortic counterpulsation in dogs with dilated cardiomyopathy

Skeletal muscle extra-aortic counterpulsation was performed in seven dogs with dilated cardiomyopathy. A left latissimus dorsi dynamic descending thoracic aortomyoplasty was used as the autologous counterpulsator. Pulse train stimulation in diastole was used to initiate contraction and fibre type transformation. Two of the dogs died within 48 hours of surgery. The device was successfully activated in the five remaining dogs, but in one individual it failed within 48 hours of activation. Serial echocardiographic examinations of dogs in which the device functioned successfully (n = 4) showed trends towards the decrease in the left ventricular systolic internal dimension, left ventricular diastolic internal dimension, E-point to septal separation and left atrial diameter in systole seven to 14 days following the procedure, although these changes failed to persist in the long-term. The results suggest that skeletal muscle for cardiac assistances such as extra-aortic muscle counterpulsation, might be a therapeutic option for dogs with cardiac failure due to dilated cardiomyopathy.     

Detection of silent intervals between noises activating different perceptual channels: some properties of "central" auditory gap detection

This article describes four experiments on gap detection by normal listeners, with the general goal being to examine the consequences of using noises in different perceptual channels to delimit a silent temporal gap to be detected. In experiment 1, subjects were presented with pairs of narrow-band noise sequences. The leading element in each pair had a center frequency of 2 kHz and the trailing element's center frequency was parametrically varied. Gap detection thresholds became increasingly poor, sometimes by up to an order of magnitude, as the spectral disparity was increased between the noise bursts that marked the gap. These data suggested that gap-detection performance is impoverished when the underlying perceptual timing operation requires a comparison of activity in different perceptual channels rather than a discontinuity detection within a given channel. In experiment 2, we assessed the effect of leading-element duration in within-channel and between-channel gap detection tasks. Gap detection thresholds rose when the duration of the leading element was less than about 30 ms, but only in the between-channel case. In experiment 3, the gap-detection stimulus was redesigned so that we could probe the perceptual mechanisms that might be involved in stop consonant discrimination. The leading element was a wideband noise burst, and the trailing element was a 300-ms bandpassed noise centered on 1.0 kHz. The independent variable was the duration of the leading element, and the dependent variable was the smallest detectable gap between the elements. When the leading element was short in duration (5-10 ms), gap thresholds were close to 30 ms, which is close to the voice onset time that parses some voiced from unvoiced stop consonants. In experiment 4, the generality of the leading-element duration effect in between-channel gap detection was examined. Spectrally identical noises defining the leading and trailing edges of the gap were presented to the same or to different ears. There was a leading-element duration effect only for the between channel case. The mean gap threshold was again close to 30 ms for short leading-element durations. Taken together, the data suggest that gap detection requiring a temporal correlation of activity in different perceptual channels is a fundamentally different task to the discontinuity detection used to execute gap detection performance in the traditional, within-channel paradigm.     

Magnetization transfer imaging in progressive multifocal leukoencephalopathy

We report a patient with biopsy-proven progressive multifocal leukoencephalopathy (PML) who was serially imaged with MRI and magnetization transfer imaging. The magnetization transfer ratio (MTR) was profoundly and significantly diminished when compared with normal control subjects. The pattern of MTR was distinct from that of MS and periventricular ischemic white matter disease. Magnetization transfer imaging techniques may aid in the differential diagnosis of PML.     

Recruitment and retention of psychosocial rehabilitation workers

Recruitment and retention of direct service workers can be a major problem for administrators of community mental health organizations. This paper, based on a nationwide study of psychosocial rehabilitation workers and administrators, examines the congruity of worker and administrator perceptions of worker motivation for entering and leaving the field. Workers are motivated by the intrinsic nature of the work to enter into and stay in the field. Job burnout is as important as low pay in forcing workers out of the field. Administrators, however, perceive money to be a major factor motivating workers to enter the field and perceive external opportunities as forces that pull them away. Thus, administrators must address their workers' needs if their agencies are to offer quality services.     

Phase I and pharmacological study of CI-980, a novel synthetic antimicrotubule agent

CI-980 (NSC 613862) is one of a novel class of 1,2-dihydropyrido[3, 4-b]pyrazines that inhibits tubulin polymerization, presumably by binding to the colchicine binding site of tubulin. In a Phase I and pharmacological study, 16 patients with advanced solid neoplasms were treated with CI-980 on a continuous 72-h infusion schedule at doses ranging from 3.0-5.4 mg/m2/day every 3 weeks. High rates of central nervous system (CNS) toxicity and neutropenia occurred in both minimally and heavily pretreated patients who were treated with CI-980 doses above 3.75 mg/m2/day, which is the maximum tolerated dose and the recommended dose for additional evaluations. CNS effects, characterized by neurocortical, mood, and cerebellar manifestations, were generally observed toward the end of the infusion and immediately posttreatment and usually resolved within 48 h after the completion of treatment. Toxicity was mild to modest at the 3.75 mg/m2/day dose level. Neither clinical nor pharmacological risk factors that may predispose patients to the development of CNS effects were evident. Although no objective antineoplastic activity was observed in this Phase I study, CI-980 steady-state plasma concentrations achieved at the recommended dose of 3.75 mg/m2/day (mean +/- SE, 5.74 +/- 0.54 nM) approached and exceeded concentrations that have been associated with significant activity in preclinical studies, indicating that additional disease-directed evaluations of CI-980 may be warranted.     

Levels and correlates of maternal nutritional status in urban Bangladesh

OBJECTIVE: To determine the levels and correlates of maternal nutritional status. DESIGN: Cross-sectional maternal weight, height, and mid-upper arm circumference (MUAC) data were correlated with sociodemographic data. SETTING: Slums of Dhaka, Bangladesh. SUBJECTS: Weight, height and MUAC were collected from a representative sample of 2417 nonpregnant mothers. Socioeconomic data such as age, education, religion and household economic status was collected from 2048 mothers; data on reproductive experiences such as number of pregnancies and number of children born alive now dead was available from 1314 mothers; and both sets of data from 1185 mothers. METHODS: Using weight, height, MUAC and body mass index (BMI) data, the levels of maternal nutritional status were estimated. Bivariate and multivariate relationships of maternal nutritional status with socioeconomic and reproductive experiences variables were examined. RESULTS: Mothers' mean weight, height, MUAC and BMI were 41.8 kg, 148.8 cm, 232.5 mm, and 18.8 respectively. In multivariate regression analyses, mothers' weight, BMI and MUAC were significantly positively correlated with mothers' years of schooling (P < 0.05) and household economic status (P < 0.01). Mothers' height was significantly positively correlated with years of schooling (P < 0.05), but not with household economic status. Maternal height and weight were significantly negatively correlated with number of child deaths (P < 0.05). CONCLUSIONS: The findings suggest a possible inter-generational effect; thus, improvement of the nutritional status of girls of this generation would improve child survival in the next generation. This, however, will require complex and long-term planning. As an interim measure, shorter mothers should be targeted for appropriate antenatal and obstetric services.