Biomedical subjects
Publications and source records attributed to J S Watson.
Two cases of migration of silastic rods into the forearm after the first stage of flexor tendon grafting are reported. A CT scan shows the rods well if they are not visible on a plain X-ray. Possible factors involved in distal detachment of the rods are the composition of the tendon spacer, method of distal fixation, method of proximal fixation and the time between the stages of reconstruction.
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The long-term functional result of exposed total knee arthroplasty, treated by flap cover, is presented and the results compared with those of a randomly selected control group. The wound was successfully covered and the prosthesis was preserved in 76% of cases, but the final functional score was not as good as in those with primary wound healing.
Skin lesions are the commonest extraintestinal manifestation of Crohn's disease. Lesions that develop at sites remote from the gastrointestinal tract and have granulomas on histological examination are termed metastatic cutaneous Crohn's disease. Management is difficult as medical treatment is often ineffective. This report describes the use of surgical debridement of areas of perineal metastatic cutaneous Crohn's disease in five patients, all of whom had failed to improve after a variety of medical treatments. One patient had a poor result with continuing mild perineal discharge and four had a good outcome with complete resolution of symptoms and satisfactory cosmetic results.
1. The sympathomimetic agent clenbuterol has a muscle-specific anabolic effect in normal and wasted muscles from animals. This trial was designed to examine the effect of the drug on the recovery of muscle strength and area after open medial meniscectomy. 2. A double-blind, completely randomized, placebo-controlled study was carried out on 20 healthy male patients. Muscle strength and cross-sectional area were determined before and after surgery. Patients were treated with drug or placebo for 4 weeks postoperatively and there was a 2 week washout period. 3. The results suggest that, in the operated leg, clenbuterol treatment is associated with a more rapid rehabilitation of strength in knee extensor muscles; in the unoperated leg, knee extensor strength increased above the initial values after 6 weeks (P = 0.01). However, in terms of absolute strength the differences were not significant between the two groups. 4. It is concluded that the data lend support to the proposition that clenbuterol has therapeutic potential in the treatment of muscle-wasting conditions.
When the motion of an object is influenced by gravity (eg free fall, pendulum, wave motion), that influence may provide a cue to computing the absolute distance and/or size of the object. Formal analysis supports the claim that the distance and size of moving objects are generally computable with reference to the gravitational component of motion. Informal evidence from judgments of realism in films is consistent with this gravity-cue hypothesis.
We have designed an anti-evaporative cover for use with the sample and reagent cups and other liquid containers that are required in automated analytical systems. This cover, which is simple in design, consists of a baseplate and a cylindrical chimney. By increasing the height and decreasing the inner diameter of the chimney, evaporative losses can be reduced to less than 0.1%/h; thus, aliquots of sample and reagents can be allowed to remain in their cups and containers for several hours before an analytical error due to evaporation will be measurable. We have also modified a model that we previously developed and validated to estimate evaporative losses from open sample cups, to allow us to predict evaporative losses from cups and containers fitted with the new type of cover. This model confirms that the magnitude of the evaporative loss is inversely proportional to the resistance provided by the headspace above the sample in the cup and by the space defined by the chimney of the cover. With chimney heights ranging from 12 to 36 mm and their inner diameters from 1 to 4 mm, greater than 70% of the resistance to evaporation is provided by the cover.
A bather on holiday in Kenya injured a finger on a spiny marine creature living on the sea bed. A skin biopsy specimen from the injured finger contained several black spines about 0.5 mm in diameter and up to 1.5 cm in length. Spines removed from the specimen were embedded in plastic resin to facilitate transverse sectioning. Light microscopical examination using crossed polarisers showed an ornate symmetrical structure brightly illuminated against a dark background. These features are characteristic of sea urchin (Echinoderm) spines which are composed of ornately formed calcite crystals covered by an epithelium. The spines of sea mice, on the other hand, are chitinous in nature; they are also much finer and lack the ornate symmetry of sea urchin spines.
An hypothesis is developed which proposes that mortality rates from heart disease are a function of a nation's dominant religious tradition, with predominantly Catholic countries having lower rates than the more Protestant countries. The hypothesis was tested on data from 24 economically developed Western countries. A significant inverse relationship of -0.588 was found between the proportion of Catholics in the 24 nations and mortality rates from heart disease, which supports the hypothesis.
A case of destructive arthritis and soft tissue granulomatous inflammation occurred in a 25 year old man who had injured his right index finger while snorkelling in the Mediterranean. It was initially thought that he had fallen on a sea-urchin. He removed some spines at the time of injury but the finger became stiff, swollen, and painful, and after eight months with no symptomatic improvement amputation through the proximal phalanx was performed. Examination showed an exuberant granulomatous and foreign body type inflammation in the dermis and subcutaneous tissues and affecting the bone, with erosion of the cartilaginous surfaces of the proximal interphalangeal joint. Spines present in soft tissue sections contained no calcium but did contain chitin as shown by a von Wisseling reaction for chitosan. It is concluded that the chitinous spines almost certainly came from a sea-mouse (Phylum Annelida, family Aphroditidae). Sea mice are inconspicuous creatures which live on the sea floor and which may cause some injuries thought to be attributable to sea-urchins.
Although relatives' retrospective reports are often used in characterizing the onset and progression of symptoms in dementia of the Alzheimer type (DAT), little is known about the accuracy of these accounts. The primary purpose of this paper is to summarize preliminary data obtained from relatives in an ongoing family study of DAT. Preliminary findings suggest there is rough reliability to relatives' recall of the progression of symptoms over time. This observation is discussed in relation to literature from other areas (e.g. child development, psychopathology) where the reliability of relatives' retrospection has been more thoroughly examined.
Primary silicone rubber arthroplasty in a total of four metacarpophalangeal joints during digital replantation or revascularisation in two patients is reported. The results appear preferable to present alternatives and allow good function without prejudicing further management.
The influence of a period of training, which lasts for several years, on the proportions of muscle, fat and bone present in the human forearm has been investigated by comparing trained and untrained limbs of nine experienced male tennis players. Ten healthy but untrained males of similar age served as a control group. Computed tomography (CT) scans of the forearm were made at intervals along its length to identify fat, muscle and bone and to calculate the volumes occupied by each of these components. Total forearm volume was greater in the dominant limb compared with the contralateral side in both trained (by 135 +/- 59 cm3, mean +/- SD, P less than 0.001) and untrained subjects (by 41 +/- 45 cm3, P less than 0.02). Forearm muscle volume was also greater in dominant limbs of trained (by 117 +/- 52 cm3, P less than 0.001) and untrained by 35 +/- 41 cm3, P less than 0.025) subjects. Muscle accounted for 75.4 +/- 2.7% of the total volume in the dominant arm of trained subjects compared with 71.4 +/- 4.2% in the control group (P less than 0.05). There was a greater proportion of muscle (P less than 0.05) and a smaller proportion of fat (P less than 0.001) in the trained limb compared with the contralateral limb of the same subjects. No differences in proportions of fat, muscle and bone were observed in dominant and non-dominant limbs of the control subjects. Trained subjects were able to exert a greater isometric force with the dominant limb (549 +/- 76N) than with the non-dominant limb (496 +/- 48N; P less than 0.005). There was no difference in grip strength between the arms of the untrained group (dominant: 516 +/- 107N; non-dominant: 491 +/- 91N). The ratio of strength to muscle volume was, however, the same in dominant and non-dominant arms of both groups of subjects.
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An evaluation of the Coulter Electronics, Inc. (Hialeah, FL) three-part differential screen (3PD) was undertaken to determine the performance characteristics of this system. The 3PD measures white blood cell (WBC) volumes and, by automatic analysis of the resultant WBC histogram, produces a determination of the number and percent of lymphocytes, mononuclear cells, and granulocytes. A group of 984 random patient blood samples was tested. The overall review rate (samples requiring some further analysis or review) was 42%. The main source of false negatives on the 3PD was eosinophilia: 5 out of 22 instances of eosinophilia greater than 750/microL were not flagged. The precision of the three parameters, measured as percent coefficient of variation, was 3.3% for lymphocytes, 14.2% for mononuclear cells, 3.1% for granulocytes, and 2.4% for the total WBC. The stability of blood samples was acceptable for up to eight hours at room temperature (less at 4 degrees C).
Of 40 patients with amputated thumbs referred for replantation to the Manchester Microsurgical Unit over five and a half years, 10 (25%) were not considered to be feasible replants, 6(15%) were abandoned at the primary operation, and 24 were replanted. Mode of selection of patients for replantation and operative methods are considered. The 14 thumb replants that survived were studied in detail and functional results are presented. Only one patient had a result that prevented normal activities, the remainder having returned to former occupations.
Chronic malnutrition, which may be induced by a number of different experimental manipulations, appears, from a survey of the literature, to lead to greater relative whole-brain-weight variability in affected groups compared with controls; there is a tendency for the same pattern to emerge in the case of body-weight variability. A hypothesis which might throw some light on this general trend is proposed.
Computed tomography has been used to establish the proportions of fat, muscle and bone present in the normal human forearm. Subjects were healthy young volunteers, eight males and eight females. A series of six cross-sectional scans at right angles to the long axis of the forearm was obtained, the scans being made at equidistant intervals between the olecranon process and the ulnar styloid. The volumes occupied by fat, muscle and bone were calculated for the complete forearm. Total forearm volume calculated by this method agreed closely with that measured by water displacement. For the male subjects, forearm composition was 72.1 +/- 4.4% muscle (mean +/- SD), 15.0 +/- 5.3% fat and 12.9 +/- 1.2% bone. Female forearms had less muscle (P less than 0.001) and more fat (P less than 0.001) than those of the male subjects: 58.5 +/- 4.0% muscle, 29.3 +/- 5.0% fat and 12.3 +/- 1.4% bone. Forearm muscle volume was significantly correlated (r = 0.75; P less than 0.05) with lean body mass in the male subjects; the range of values for lean body mass in the female subjects was too small to permit calculation of the equivalent relationship. Forearm fat content, as a percentage of total volume, was proportional to whole body fat content as estimated from skinfold thickness (males, r = 0.84; P less than 0.01; females, r = 0.77; P less than 0.05). These relationships enable estimates of the volumes of forearm tissue components to be derived from anthropometric measurements.