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Biomedical subjects

J B King

Publications and source records attributed to J B King.

At least 37 records · Page 2Linked to original sources

Vocal matching of frequency modulation in synthesized vowels.

Nine male singers attempted to match rates and extents of synthesized vocal vibrato at low, middle, and high pitch levels. The results showed that on average, the singers were able to match rates of 3, 5, and 7 Hz within 13%. It was difficult for the singers, however, to match extents of 0.5, 1.0, and 1.5 semitones. Thus, the results indicated singers' reasonably good ability to match rates but, contrary to prevalent opinions, not extents of vocal vibrato.

Adult↗

Acute haemarthrosis of the knee in athletes. A prospective study of 106 cases.

We made a prospective arthroscopic study of 106 skeletally mature male sportsmen with an average age of 28.35 years (16.8 to 44) who presented with an acute haemarthrosis of the knee due to sporting activities. We excluded those with patellar dislocations, radiographic bone injuries, extra-articular ligamentous lesions or a previous injury to the same joint. The anterior cruciate ligament (ACL) was intact in 35 patients, partially disrupted in 28 and completely ruptured in 43. In the patients with an ACL lesion, associated injuries included meniscal tears (17 patients), cartilaginous loose bodies (6), and minimal osteochondral fractures of the patella (2), the tibial plateau (3) or the femoral condyle (9). We found no age-related trend in the pattern of ACL injuries. Isolated injuries included one small osteochondral fracture of the patella, and one partial and one total disruption of the posterior cruciate ligament. Three patients had cartilaginous loose bodies, and no injury was detected in five. Acute traumatic haemarthrosis indicates a serious ligament injury until proved otherwise, and arthroscopy is needed to complement careful history and clinical examination. All cases with a tense effusion developing within 12 hours of injury should have an aspiration. If haemarthrosis is confirmed, urgent admission and arthroscopy are indicated.

Acute Disease↗

Isolated ganglions of the anterior cruciate ligament.

We report three athletes with symptomatic isolated ganglion of the anterior cruciate ligament. The symptoms consisted of anteromedial knee pain, worse when changing direction while running, and on squatting. All gave a history of repeated minor knee trauma without a single episode of serious injury. At day-case arthroscopy, a unilobulated cystic mass arising from a clinically and arthroscopically intact anterior cruciate ligament was noted and removed in each case. No further intra- or extra-articular knee lesion was seen. Histology revealed a cystic ganglion in each case. With early physiotherapy, the patients could start gentle training 3 wk after arthroscopy, and, at 6-month review, were fully asymptomatic. A review of the literature shows that an isolated ganglion arising from the anterior cruciate ligament is exceedingly rare, with only three such ganglia having been previously reported.

Adult↗

The effect of repeated instillations of antiseptics on catheter-associated urinary tract infections: a study in a physical model of the catheterized bladder.

The activity of three antiseptic bladder washout solutions was examined in a physical model of the catheterized bladder. Tests were performed against cultures of four common urinary tract pathogens that had established themselves in the model and colonized the surfaces with biofilm. Double instillations of chlorhexidine (0.02% w/v) at 6-h intervals failed to eliminate Pseudomonas aeruginosa, Proteus mirabilis, and Providencia stuartii from the bladder model. Escherichia coli, however, was susceptible to a second instillation provided that it was performed within 12 h. Supplementing chlorhexidine with EDTA and TRIS potentiated its activity against E. coli. Mandelic acid (1.0% w/v) was the most effective of the agents, double instillations eliminating all but Pr. mirabilis infections.

Administration, Intravesical↗

Focal points in orthopaedics.

Orthopaedic surgeons have long had an association with sport, although it is arguable whether Galen who was the first sports medicine doctor, appointed to the Pergamum Gladiators in 157 AD was a surgeon by todays definition. This surgical role is now out of proportion to the more global aspects of sports medicine as reflected in the rest of this publication, but accurately related to the consequences of injury to the elite performer, where a minor injury may have a major consequence. As the title makes clear this chapter is a series of cameos some describing aspects of the management of common injuries and others indicating new developments.

Anterior Cruciate Ligament Injuries↗

Effects of physical activity on some components of the skeletal system.

Sporting activities impose on the skeletal system forces of a high intensity and frequency. Ligaments, bone and tendons behave in a time-dependent load-extension fashion, and it is important for both scientists and clinicians to consider, for example, the alterations in failure properties shown by ligaments, tendons and bone at different rates of deformation. Whether the ability of the skeletal system to withstand stress can be improved with appropriate training is still controversial. The effects of physical exercise depend on the modality, intensity and duration with which the exercise itself is performed. Moreover, genetic factors, also influencing growth and hormonal status, may exert a significant influence on the response of a given tissue to an external load. Overloading may cause a lesion, and this may decrease or annihilate performance capability. The skeletal system may not be resistant enough, and so it may prove limiting to intensive physical activity. In vitro studies on resistance of a single tissue have not taken into consideration the specific resistance of that structure in vivo, and the results so obtained cannot be readily extrapolated to sporting activities, as in vivo muscles, joints, tendons, ligaments and cartilage act as one. This article reviews some of the possible beneficial and detrimental effects of intense exercise on various components of the skeletal system, focusing on its ability to withstand and adapt to stresses and allow maximal performance.

Bone and Bones↗

Public health service administration and academia. A joint venture.

Joint ventures between service and academia are designed to enhance the quality of client services, enrich faculty teaching experiences and skills, and strengthen communication channels. The joint venture described in this article is an example of how public health nursing services and academia can be united through faculty participation in administration. Included in the discussion are the impetus for the project, the contract negotiations, the positive outcomes and disadvantages of the venture, and questions that should be raised when a similar venture is considered.

Cost Savings↗

An assessment of antiseptic bladder washout solutions using a physical model of the catheterized bladder.

The antibacterial activity of six antiseptic solutions formulated for use in bladder washout procedures has been examined in a simple model of the catheterized bladder. The experiments were carried out under conditions which examined the efficacy of the formulations against organisms that had recently contaminated the bladder urine. At cell densities of 10(4) cfu ml-1 all the solutions tested proved effective in eliminating bacteria from the bladder urine. Under conditions simulating heavy contamination (10(7)-10(8) cfu ml-1) however, only mandelic acid (1% w/v) eliminated the range of bacterial species commonly responsible for catheter-associated urinary tract infection.

Administration, Intravesical↗

Ultrasound, computed tomography and magnetic resonance imaging in patellar tendinitis.

This prospective study describes the ultrasound, computerized tomography and magnetic resonance imaging findings in 16 cases of patellar tendinitis. In all cases tendon enlargement and reduced echogenicity were visible on ultrasound. Computerized tomography demonstrated enlargement of the tendon with reduced attenuation of the central portion. Magnetic resonance imaging showed focal tendon enlargement in all patients with high signal lesions in 88% of cases. This study has shown that patellar tendinitis may be identified with all three modalities. Ultrasound is recommended as the initial investigation in the assessment of patients with this condition.

Adult↗

Comparative study of intra-articular pressure dynamics in joints with acute traumatic and chronic inflammatory effusions: potential implications for hypoxic-reperfusion injury.

It has been proposed that the process of hypoxic-reperfusion injury contributes to the persistence of synovitis in the inflamed human joint. The generation of pathological, exercise induced, intra-articular pressure leading to occlusion of the synovial microcirculation is central to this mechanism. However, acute traumatic inflammatory joint effusions rarely result in chronic synovitis, suggesting that either the basic hypothesis is incorrect, or that joints with acute traumatic effusions show different intra-articular pressure dynamics. In this study the intra-articular pressure was measured at rest and during isometric exercise in five patients with acute traumatic joint effusions and in nine patients with chronic inflammatory joint effusions. The generation of intra-articular pressure in the patients with acute traumatic effusions was significantly lower at rest (mean 2.0 v 19.6 mm Hg) and during exercise (mean 13.7 v 222.5 mm Hg) than in the patients with chronic effusions. This was due to reflex muscular inhibition around the joint, which inhibited the pathological generation of intra-articular pressure. This difference in the ability to generate intra-articular pressure might mitigate against hypoxic-reperfusion injury in joints with acute traumatic effusions, thereby explaining the paradoxical clinical observation that patients with acute traumatic inflammatory joint effusions rarely develop chronic synovitis.

Acute Disease↗

Lesions of the patellar ligament.

We report 18 cases of pain and tenderness in the mid-part of the patellar ligament in athletes. The condition may be disabling, but it responds to surgery. Ultrasound and CT scans were positive in all 17 confirmed cases, but ultrasound gave a better distinction between the cysts, granulation tissue, metaplasia, mucoid degeneration and congenital defects found at operation.

Adolescent↗

Severe rhesus iso-immunization successfully treated with apheresis and azathioprine. Report of 2 cases.

Two patients are described in whom previous fetal loss had occurred due to rhesus (Rh) disease. In both patients apheresis was performed from a gestational age of 25 weeks in an attempt to remove excessive antibodies. In addition, production of new antibodies was suppressed by the administration of prednisone and azathioprine. A reduction in the antibody titres was accomplished although this was not reflected by a marked decrease in amniotic fluid bilirubin levels. The patients were delivered at gestational ages of 32 and 33 weeks since fetal lung maturity had then been demonstrated. Both babies were surprisingly little affected by the Rh disease and only one exchange transfusion was necessary for each. Neonatal follow-up for 2 years and 1 year respectively revealed no fetal abnormalities.

Adult↗

Sports medicine.

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Education, Medical, Graduate↗

A nosocomial outbreak of Crimean-Congo haemorrhagic fever at Tygerberg Hospital. Part II. Management of patients.

During the outbreak of Crimean-Congo haemorrhagic fever (CCHF) at Tygerberg Hospital 8 patients were diagnosed positive. CCHF was diagnosed in another patient several months later. The treatment of these 9 cases is outlined. When it became evident that CCHF could present with a spectrum of severity, treatment was adjusted according to each patient's requirements. The essential components consisted of correction of haematological abnormalities combined with hyperimmune serum; the latter is particularly important for the severely ill patient with no antibodies to CCHF. The antiviral agents ribavirin and interferon were used but evidence to substantiate their application in future cases was inconclusive. Interferon was discontinued because of severe side-effects, many of which simulated the clinical features of CCHF. Objective improvement after corticosteroid treatment was noted in only 1 patient, but some of her symptoms could have been due to a transfusion reaction. Antibiotics were not routinely used. The 2 patients who died were diagnosed late, did not receive hyperimmune serum, and eventually developed multi-organ failure. The course of CCHF can probably be modified if the diagnosis is made early, if antiserum is given, and if the haematological abnormalities are promptly corrected.

Adult↗

A nosocomial outbreak of Crimean-Congo haemorrhagic fever at Tygerberg Hospital. Part IV. Preventive and prophylactic measures.

During the Crimean-Congo haemorrhagic fever (CCHF) outbreak at Tygerberg Hospital a particular problem existed: a simultaneous influenza epidemic complicated the screening of contacts because of its very similar clinical picture to that of early CCHF. The methods of identifying and screening contacts are described. Of 459 listed CCHF contacts, 7 (1,5%) developed the disease; 6 were contacts of the index case and only 1 a contact of a secondary case. Two of the 7 CCHF patients had no direct contact with the index case; this caused great concern about the dissemination, despite the otherwise full protective measures. Four of 46 blood contacts (8,7%) and 3 of 9 needle contacts (33%) developed the disease. Prophylactic interferon therapy had to be discontinued because of side-effects mimicking the symptoms of CCHF. Ribavirin was used prophylactically in 6 of the 9 inoculation contacts. One of the patients on ribavirin had a mild clinical course while 5 others who received the drug developed neither clinical CCHF nor antibodies to the virus. Two of the 3 needle contacts not treated with ribavirin had a severe clinical course. One contact with needle inoculation and 42 proven blood contacts who had not received ribavirin did not become infected. No firm conclusion can therefore be made about the protective value of prophylactic ribavirin.

Adult↗

A nosocomial outbreak of Crimean-Congo haemorrhagic fever at Tygerberg Hospital. Part III. Clinical pathology and pathogenesis.

Crimean-Congo haemorrhagic fever (CCHF) was diagnosed in 8 patients; 7 were staff members at Tygerberg Hospital who had been infected by a patient in whom the disease had not initially been diagnosed. Two patients, the initial case and a staff member, died and 4 became seriously ill. The immunopathogenesis of CCHF appears to be multifactorial. Certain features were common to all patients--leucopenia, thrombocytopenia, elevated liver enzyme values and low serum total protein levels. Ultrastructural changes in and around skin capillaries, including intracytoplasmic endothelial tuboreticulated bodies, were found. Virus-like particles were found on electron microscopy. Important individual factors related to prognosis were identified. The patients who survived all mounted a good antibody response, and manifested no coagulation defect extensive enough to explain the haemorrhagic tendency. In the patients who died no evidence of antibody production was detected; both developed diffuse intravascular coagulation and in 1 evidence of immune complex formation and complement consumption was found. Hepatorenal failure and cardiovascular collapse characterized the terminal period. Early clinical recognition of CCHF with specific attention to factors amenable to treatment may vastly improve the prognosis.

Adult↗