Biomedical subjects
Publications and source records attributed to M J Rowe.
Scanning and transmission electron micrographs demonstrate a calcification process in the penile plaques of patients with Peyronie's disease. Osteoid formation originates from vascular lumina via osteoblast-like cells, which align the calcified plaque. These cells are surrounded gradually by calcified connective tissue. Collagen fibers demonstrate calcification and decreased periodicity.
Cell cultures derived from Peyronie's disease plaque and normal penile tissue were characterized morphologically and examined by immunofluorescence for actin cable formation, and their growth properties were compared. Relative to normal penile cell cultures which grew as contact inhibited, poorly refractile fibroblast-like cells, plaque derived cell cultures consisted of round and spindle shaped cells that were more refractile and exhibited random crisscross growth patterns. Scanning electron microscopy of plaque derived cell cultures revealed changes in cell surface topography characterized by the appearance of surface membrane blebs amd microvilli. Transmission electron microscopy demonstrated cells containing organized cytoplasmic microfilament bundles and nuclear indentations which resembled myofibroblasts. Such alterations were less extensive or absent in normal penile cell cultures. The amount and extent of actin cable formation was increased in plaque derived compared to normal penile cell cultures. Plaque derived cells also exhibited differences in growth properties and grew to higher saturation densities than their normal counterparts. These results demonstrate that cells derived from Peyronie's disease plaque can be grown in vitro and that these cells are morphologically altered and have an enhanced proliferative capacity. The availability of these cell cultures will permit studies directed at understanding the etiology and pathogenesis of Peyronie's disease.
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cAMP-dependent protein kinase was examined in mitochondria and cytosol prepared from different-sized antral follicles and corpora lutea of porcine ovaries. In all ovarian tissues examined except small follicles, protein kinase-specific activity was significantly higher in mitochondria than in cytosol, with the highest to lowest activities being found in medium (4-6 mm) follicles, large (7-12 mm) follicles, corpora lutea, and small (1-3 mm) follicles, respectively. Using the photoaffinity analogue [32P]8-N3cAMP, two major cAMP binding proteins with Mr = 47,000 (the apparent regulatory subunit of protein kinase Type I) and 54,000-56,000 (Type II) were found in all ovarian preparations. Type II was predominant in the cytosol of all ovarian samples, with the cytosolic Type I to Type II ratio increasing from approximately 0.05 in small and medium follicles top approximately 0.20 in large follicles and corpora lutea. In contrast, ovarian mitochondrial preparations contained relatively more Type I than did cytosol, with the mitochondrial Type I to Type II ratio increasing from approximately 0.50 in small and medium follicles to 0.88 in large follicles and 2.96 in corpora lutea. Also, mitochondrial [4-14C]cholesterol conversion and 3 beta-hydroxysteroid dehydrogenase/isomerase activities increased with follicle size and luteinization. These results suggest that Type I may play a role in the regulation of ovarian mitochondrial steroidogenesis.
A stimulus technique is described where left and right half fields of a video checkerboard pattern reverse sequentially at a 245 msec interval. The pattern VEPs are recorded on a 512 msce timebase. This allows VEPs to left and right half-field reversal to be obtained on the same sweep, cutting total stimulus time required for testing in half. Normal values for absolute and relative latency and amplitude are given.
In the neonatal kitten, cuneate neurones activated by tactile stimulation of the forelimb foot pads are divisible into 3 functional classes each of which appears to receive its glabrous skin input selectively from a single class of tactile receptors. Their properties suggest that the functionally specific patterns of tactile convergence characteristic of the adult cuneate nucleus are established by the time of birth.
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Twenty-seven patients with postconcussion dizziness following minor injury to the head or neck had brainstem auditory evoked potential studies from one day to eight months (median, 37 days) following injury. All patients were normal on clinical examination at the time of study. Three patients had one or more interpeak latencies prolonged beyond the 99% tolerance limit for normal control subjects. The group mean 1-3, 2-3, and 1-5 interpeak latencies were significantly prolonged. These findings indicate that minor head or neck injury with associated subjective symptomatology may be accompanied by objectively demonstrable brainstem dysfunction.
A rapid, inexpensive method is described for achieving accurate reproduction of histological sections. The method uses a microfiche reader-printer (for library use) which produces A4 size prints. Interchangeable lenses on the microfiche printer permit the magnification of the section to be varied over the range 6.6-72 times. Where large numbers of sections are involved the speed and low cost of the method offers considerable advantages over traditional hand tracing or photomicrography.
A study comparing the effects of bran and ispaghula in constipated elderly patients is described. Ispaghula and bran increased the wet and dry stool weight. There were no serious side-effects and no change in colonic pressures. The use of these bulking agents is shown to be better than the traditional use of laxatives in the elderly.
1. Responses were recorded from individual tactile afferent fibres isolated by microdissection from the median nerve of pentobarbitone-anaesthetized neonatal kittens (1-5 days post-natal age). Experiments were also conducted on adult cats to permit precise comparisons between neonatal and adult fibres.2. Neonatal fibres with receptive fields on the glabrous skin of the foot pads were classified into two broad groups, a slowly adapting class (40%) which responded throughout a 1 sec period of steady indentation and a rapidly adapting or dynamically sensitive class comprising 60% of units. Fibres in these two groups had overlapping conduction velocities in the range 4.3 to 7.5 m/sec and were believed to be the developing Group II afferents of the adult.3. Neonatal slowly adapting fibres qualitatively resembled their adult counter-parts. They displayed graded stimulus-response relations which, over the steepest segment of the curves, had mean slopes of 15.7 impulses/100 mum of indentation. Plateau levels of response were often reached at amplitudes of skin indentation of < 0.5-0.7 mm.4. Dynamically sensitive fibres with receptive fields on the glabrous skin were studied using sinusoidal cutaneous vibration which in the adult enables them to be divided into two distinct classes. However, in the neonate, they formed a continuum whether criteria of sensitivity or responsiveness were used.5. In response to vibration neonatal fibres differed from adult ones according to the following quantitative indices: (i) sensitivity as measured by both absolute thresholds and thresholds for a 1: 1 pattern of response, both of which were higher in the neonate than in the adult at all frequencies > 50 Hz and differed by an order of magnitude at frequencies >/= 200 Hz; (ii) responsiveness based on the mean impulse rate evoked at a fixed amplitude of cutaneous vibration; (iii) band width of vibratory sensitivity which in the neonate was confined to approximately 5-300 Hz whereas in the two classes of adult units it covered the range 5-800 Hz; (iv) capacity for coding information about vibration frequency. Impulse activity of neonatal fibres was less tightly phase-locked to the vibratory stimulus and showed a poorer reflection of the periodic nature of the vibratory stimulus than impulse patterns of adult units.6. The results reveal that tactile receptors and afferent fibres in the neonate are functionally immature. Their restricted coding capacities suggest that peripheral tactile sensory mechanisms impose limits on the ability of the new-born animal to derive information about its tactile environment.
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Electrocardiographic tracings were recorded continuously to monitor ventricular tachycardia and R-on-T and R-on-apex-T ventricular premature beats, and repeated estimations of venous plasma total catecholamine concentrations were carried out in 26 patients admitted to a coronary care unit with acute myocardial infarction. No relation existed between the increased catecholamine concentrations found in these patients and the incidence of ventricular arrhythmias occurring six to 48 hours after the onset of symptoms.
The brain-stem auditory evoked response was studied under three combinations of intensity and rate of click stimulation in 25 young and 25 old adult subjects. The responses show a great intra and inter subject variability. Waves 1, 3 and 5 are constant and reproducible markers of the response while waves 2, 4, 6, and 7 are variable and frequently asymmetrical or absent. Wave peak latencies increase with an increase in stimulation rate, a decrease in stimulus intensity and an increase in age. Interpeak conduction times, except those involving wave 2, are unaffected by a change in stimulus intensity. Wave 1-3 time increases with an increase in stimulus rate and an increase in age while wave 3-5 time is not affected by any change in stimulus parameters or age. Wave amplitude alone is not a reliable measure of normality. Normal values for peak latencies, interpeak conduction times and interear symmetry are presented. One tailed 95 and 99% confidence intervals for normal interpeak conduction times are presented with appropriate corrections for stimulus rate used and patient age. No corrections need to be made for changes in stimulus intensity. This suggests that no correction is necessary when studying patients with conductive type hearing deficits. Laboratories using the same stimulation technique appear to produce equivalent normative conduction time values.
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1. Mossy and climbing fiber inputs from cutaneous mechanoreceptors to Purkynĕ cells of vermis and pars intermedia of the cerebellar anterior lobe were studied in locally anesthetized, paralyzed cats prepared for painless recording sessions. In this preparation the mossy fiber and climbing fiber pathways remain fully functional. Simple spikes and climbing fiber discharges were recorded simultaneously through extracellular glass micro-electrodes and thereafter filtered off from each other for separate, computer-assisted analysis. Controlled mechanical stimulation (air jets, taps, pressure) was performed on the foot pads of all four limbs and on the hairy skin of the limbs and the body. 2. Long term recording of the spontaneous activity of 110 Purkynĕ cells revealed a simple spike activity of 85 imp./s +/- 49 imp./s (mean +/- S.D.) and 1.00+/-0.78 climbing fiber responses per second. 3. Taps to foot pads and air jets to hairy skin revealed that most of the short latency responses via mossy fibers resulted from activation of the receptors of the ipsilateral forefoot. With the same stimuli climbing fiber discharges from the ipsilateral feet were more frequently evoked than from the contralateral feet. Both via mossy and climbing fibers the contralateral hindlimb gave the smallest contribution. 4. Simple spike responses were evoked more commonly by pad stimulation (tap stimuli) than by hair stimulation (air jets). For both types of stimuli excitatory responses were more frequent (3:1) than inhibitory ones. Similarly, pad stimulation was more effective than hair stimulation in inducing climbing fiber responses. Ipsilateral stimuli were much more effective than contralateral ones in evoking both simple spike and climbing fiber responses. 5. Steady pressure stimuli modify the Purkynĕ cell discharges via mossy and climbing fiber pathways. Excitatory and inhibitory effects often of very long duration have been observed via both pathways. Again the ipsilateral forelimb was more effective than the other limbs. Mossy fiber responses were at least three times as common as climbing fiber responses and excitatory responses were more frequent than inhibitory ones. 6. There is no apparent relation between the spontaneous discharge rates of the Purkynĕ cells and the response magnitudes of the mossy fiber and climbing fiber induced excitatory and inhibitory changes inthe impulse pattern of Purkynĕ cells during steady pressure stimuli.
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