Biomedical subjects
Publications and source records attributed to J R Thompson.
Ten patients with malignant primary neoplasms of the ear and temporal bone were examined with high-resolution computed tomography (CT) and the results correlated with the operative findings. CT was found to be highly accurate in establishing the presence and extent of tumor and is recommended as the procedure of choice for preoperative treatment planning.
Data of 22,691 observations on parturition related problems (dystocia, calf mortality, milk fever, retained placenta, and mastitis) were collected from 27 cooperating California dairy herds. Age at first calving did not affect calving difficulty; thus, an optimal age for first calving was not identified. Decisions on breeding virgin heifers should be based on size of cow because of the effect of size of cow on difficulty at first parity. Small calves experienced greatest mortality at parities greater than one; however, large calves had greater mortality at first parity. Greater mortality for large calves at first parity was partially due to the increased difficulty associated with larger calves. Calving difficulty resulted in impaired reproductive performance (more days open, more services, and more days to first breeding) and decreased 30-day milk production but had no effect on 90-day milk production and 305-day mature-equivalent milk production. Dystocia, milk fever, and retained placenta occurred as a complex. Incidence of dystocia and calf mortality decreased with parity, and all other problems increased with parity.
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Sixteen patients with intracranial air under tension and severe neurological symptoms following trauma and neurosurgical procedures were reviewed. Computed tomography (CT) was performed in cadavers following selective air injections into the epidural, subdural, and subarachnoid spaces. The characteristic CT appearance of air in the various intracranial compartments is illustrated. The typical "peaking" of the frontal lobes in subdural tension pneumocephalus is explained by bridging veins entering the superior sagittal sinus. Stretching and rupturing of these veins may be implicated as a cause for a concomitant subdural hematoma. The various mechanisms causing tension pneumocephalus and its appropriate therapy are discussed.
A prospective study of 582 pediatric cranial computed tomographic (CT) examinations was made in order to determine the efficacy and safety of two sedation regimens and general anesthesia. Two hundred seventy-nine outpatients were randomly given oral chloral hydrate (80 mg/kg) or an intramuscular preparation composed of atropine, meperidine, promethazine, and secobarbital (AMPS). Three hundred three inpatients were randomly administered chloral hydrate, the AMPS, or endotracheal anesthesia. Intravenous supplementation of the sedation was limited by the protocol to a maximum secobarbital dosage of 2 mg/kg. An additional retrospective analysis was made of 316 scan attempts obtained outside the study during the same period. A failed CT examination was defined as one that could not be completed or one that showed motion artifacts on two or more scan pairs after two scan pair repeats. The failure rate was 15% for the chloral hydrate group and 12% for the AMPS group. No motion artifacts were present on 94% of the completed studies. There was no mortality, but major and minor complications occurred in 3.5% of the randomized group. It was concluded that each of the methods had proved acceptably safe and effective and that measures can be taken to decrease complications and sedation failures further.
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Normal and osteochondrotic femurs and humeri were obtained from five normal and 15 lame adolescent boars to study the molecular size of joint cartilage chondroitin sulfate. Histological examination of cartilage showed a locally reduced intensity of safranin-O staining in fractured areas. Sephadex G-200 chromatography of cartilage glycosaminoglycans revealed a reduction (P less than 0.01) in the average hydrodynamic size of chondroitin sulfate in only the separated cartilage from severely damaged medial humeral condyles. Chromatography also suggested an accumulation of fragmented chondroitin sulfate chains in this cartilage. There were no other appreciable differences in the hydrodynamic size of chondroitin sulfate from normal and osteochondrotic joint cartilage.
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Abnormalities and age-related changes in the anconeal processes of 60 boars were studied. Postmortem examination of both cubitus joints from 25 lame adolescent boars and from 5 of their nonlame contemporaries revealed cartilaginous tissue (termed cartilage plate) of varying size between the anconeal process and the ulnar diaphysis in 8 of the lame animals. The cartilage plate was fractured in both joints from 7 of these 8 animals, and joints from 6 animals with cartilage plate were associated with lesions of the semilunar articular cartilage and bone in the proximal portion of the ulna. Postmortem examination of the joints from 30 boars (ranging in age from 1 month before birth to 1.5 years) indicated that during growth, bone developed from the ulnar diaphysis toward the cranial tip of the anconeal process. Separate ossification centers were not observed in any of the clinically normal anconeal processes studied in this group. However, microscopic observations of 1 abnormal anconeal process from a 13-week-old boar indicated that trauma may be involved in morphogenesis of a cartilage plate. Age-dependent changes were also observed in the composition of the anconeal process.
Percutaneous transluminal angioplasty was used to successfully dilate critical narrowings of the internal carotid artery caused by fibromuscular dysplasia. The technique of this new procedure is presented along with the angiographic findings and results in three patients. Angioplasty may be used as an alternative to open arteriotomy and graduated dilatation in treating stenosis due to symptomatic fibromuscular dysplasia in the immediate extracranial part of the internal carotid artery.
An investigation of the identifiable real-time sonographic features of the normal infant brain in the horizontal, coronal, inclined coronal, and midsagittal planes was undertaken. Correlations were made of sonograms of intact brains in vitro, corresponding brain sections, and sonograms in vivo. A large number of anatomic structures could be consistently depicted including cisterns, fissures, faix cerebri, tentorium cerebelli, ventricles, brainstem, cerebellum, basal ganglia, thalami, and corpus callosum. Pulsations of intracranial arteries, visible by real-time sonography, were of considerable help in identifying various structures. The investigation provides a reference of sonographic anatomy of the brain displayed in four clinically useful imaging planes.
Genetic correlations between dystocia in first with later parities and between direct with maternal effects for dystocia were estimated. Dystocia in first and later parities represent similar traits because of a large genetic correlation of .84. This similarity should allow calving reports on older dams and heifers to be combined in predicting a bull's calving performance. Correlations for direct with maternal effects were -.38 for the heifer population and -.25 for the cow (second and greater parities) population. This correlation would reduce progress from selecting for reduced dystocia if only direct effects were considered. Breeding programs to reduce dystocia should consider both direct and maternal performance.
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Many currently accepted obstetrical practices exemplify a maximin strategy: making the best of the worst possible outcome, regardless of the actual probability of that outcome occurring. But a survey of recent obstetrical research fails to document superior clinical results when this strategy is employed in routine obstetrical care. Most research has studied obstetrical technologies in isolation rather than as parts of systems of interconnected interventions: this approach has tended to underestimate the risks of intervention and to overestimate the utility of a maximin strategy. Physicians practicing obstetrics should adopt a flexible approach and match the degree and type of intervention to actual patient needs. Better methods of assessing preventable prenatal risk are needed to allow identification of the rare-obstetrical patient requiring maximal intervention.
Age related changes and osteochondrosis in swine were studied using light microscopy and electron microscopy in articular cartilage and light microscopy and epiphyseal cartilage of swine from three days to 30 weeks of age. Thickness, cellularity and vascularity of both the epiphyseal and articular cartilage, decreased as the swine aged. Osteochondrotic changes included formation of "plugs" of cartilage indicating localized failure of ossification and separation and space formation in epiphyseal cartilage. Eosinophilic streaks and space formation in epiphyseal cartilage was observed in relation to epiphyseal separation. Electron microscopy showed a continuous fibrillar layer on the surface of the cartilage corresponding to the lamina splendens of light microscopy. This layer increased in the thickness and showed accumulation of amorphous material between the fibrils with aging. In the matrix, the orientation and distribution of the collagen fibers changed with growth and thicker fibers with clear sub banding were more common in older age groups. Also, necrotic cells, glycogen containing bodies and cellular debris were noticed in the matrix of normal cartilage in old animals. Chondrocytes in the younger cartilage showed accumulation of organelles responsible for protein synthesis; while Golgi bodies, vesicles, lysosomes, well developed foot processes and other inclusions were noticed in older cartilage. Cartilage erosions had a clumped and disrupted lamina splendens on the surface and electron lucent patches in the ground substances of the matrix and chondrocyte cytoplasm.
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