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Biomedical subjects

R Hicks

Publications and source records attributed to R Hicks.

At least 91 records · Page 5Linked to original sources
PubMed1987

Gait patterns in spastic hemiplegia in children and young adults.

Four homogeneous patterns of gait were defined in forty-six patients who had spastic hemiplegia secondary to cerebral palsy or other neurological disorders by analyzing kinematic data in the sagittal plane and electromyographic data. In Group I (twenty patients) the primary abnormality was a drop foot in the swing phase. The thirteen patients in Group II had a tight heel cord in the stance phase as well as a drop foot in the swing phase. The five patients in Group III also had more proximal involvement (that is, restricted motion of the knee) as well as an equinus deformity of the ankle. In Group IV, the eight patients had, in addition, restricted motion of the hip.

Adolescent↗
PubMed1986

[Possibilities of ultrasound diagnosis in dermatology].

At present, ultrasound is the only available non-invasive method to give information about in vivo structures of the skin. We report on the most important physical fundamentals and technical requirements for diagnostic ultrasound in dermatology. Furthermore we discuss the actual clinical use of the technique.

Elasticity↗
PubMed1986

Cardiotoxic and bronchoconstrictor effects of industrial metal fumes containing barium.

For certain metal arc-welding and other metal processing operations, compounds of barium are used as flux components. Airborne fumes generated by welding with electrodes using barium fluoride or carbonate fluxes may contain 15-30% of barium in readily water-soluble form (Dare et al. 1984). Urine of welders inhaling such fumes was shown to contain elevated levels of barium ions (up to 234 micrograms/l). To assess the possible hazards of such exposure, the toxic potencies of fume samples, expressed in terms of their water-soluble barium ion contents, were compared with effects of solutions of barium salts in anaesthetised guinea-pigs. Dose-effect relationships were established and it was verified that acute toxic effects of inhaled aerosols or of intravenous bolus administration correlated with the barium contents of various forms of welding fumes. Bronchopulmonary reactivity to the barium was observed as marked increases in resistance to ventilatory air-flow, indicating bronchoconstriction. Simultaneously, marked pressor effects on blood pressure occurred. ECG abnormalities indicated myocardial hyperexcitability. Effects were modified by nifedipine and propranolol pretreatments.

Air Pollutants, Occupational↗
PubMed1986

Prevalence of plaque, gingivitis and caries in 11-12-year-old children in South Wales.

The overall eruption and dental disease status of a group of 1015 11-12-yr-old schoolchildren in South Wales is presented. The mean number of teeth erupted was 21.8 with a distribution pattern reflecting continuing eruption of teeth at this age. Almost equal numbers of contralateral and opposing tooth types were present with exceptions including maxillary canines and lateral incisors. DMFT, DMFS, and DFS scores were consistent with other recent studies. The mean plaque score was 2.44 and showed a normal distribution for the group. All children had gingivitis at one or more sites as evidenced by bleeding on probing, and again the distribution pattern was a normal one. The mean pocketing was 1.24 mm and there was little clinical evidence of chronic periodontitis. As expected, plaque and gingivitis showed a very high and significant correlation, with plaque and pocketing and gingivitis and pocketing having lower correlation coefficients which were nevertheless highly significant.

Child↗
PubMed1985

Swing phase control with knee friction in juvenile amputees.

Above-knee amputees have a slower than normal walking velocity. In conventional prostheses the solution has been to apply knee friction to attempt to match the cadence of the prosthetic limb to the sound limb. Using kinematic data, we investigated the effect of variable knee friction on the swing phase of gait in juvenile amputees. The subjects were instructed to walk at a comfortable pace and were tested repeatedly with varying amounts of knee friction. We found that the excursion of the prosthetic shank as measured by knee range of motion was altered by changing the amount of knee friction. The period of the prosthetic shank remained constant when measured as a physical pendulum and when measured dynamically during gait. Therefore, knee friction is an effective means of providing the amputee with a more symmetrical appearing gait by matching the heel rise of the prosthetic limb to the sound limb. It is not an effective means, however, of matching the cadence of the prosthetic limb to the sound limb.

Artificial Limbs↗
PubMed1985

Intravenous etidronate in the management of malignant hypercalcemia.

The treatment of hypercalcemia remains a common problem in the management of many patients with cancer. We have used intravenously administered etidronate disodium as a therapy for hypercalcemia in 26 patients with malignant disease. Patients with persistent hypercalcemia despite adequate hydration and a serum creatinine level less than or equal to 1.5 mg/dL were allowed on study. Treatment consisted of intravenously administered etidronate disodium at 7.5 mg/kg/day in 250 mL of saline infused over two hours on 1, 2, 3, or 4 consecutive days. The serum calcium level in 19 (73%) of 26 patients returned to the normal range with a mean response time of 3 +/- 2 days. Similar response rates were seen in patients with a variety of tumors, including breast cancer, non-small-cell lung cancer, and multiple myeloma. Intravenously administered etidronate appears to be safe and effective therapy for hypercalcemia in patients with malignant disease.

Adult↗
PubMed1984

Pneumoconiotic effects of welding-fume particles from mild and stainless steel deposited in the lung of the rat.

Rats were exposed to single periods of inhalation of fumes generated by arc welding. Two processes were compared: either manual metal arc (MMA) using flux-coated mild steel (MS) electrodes or metal inert-gas (MIG) welding with stainless steel (SS). Widespread but small deposits of fume particles were cleared effectively from alveoli and airways. Peribronchial and subpleural aggregates of particle-laden macrophages remained. More massive and persistent lung-burdens were established by intratracheal administration of suspensions of fume-particles (10 mg and 50 mg, single doses). Initial pneumonitis was attributed to irritant gases or soluble toxic components of particles. MIG-SS particle deposits were more persistent and lesions more severe, inhibition of phagocytosis or clearance and damage to epithelial cells being associated with possible toxic effects in macrophages. Both types of particle caused alveolar epithelial thickening, with proliferation of granular pneumocytes and exudation of lamellar material. Foam cells appeared in alveoli. Long-term effects (80-300 days) involved formation of nodular aggregates of particle-laden macrophages. Giant cells were formed. Nodules containing MIG-SS material were irregular and surrounded by collapsed and thickened epithelium. Soluble chromium or nickel constituents are cited as probable active agents producing effects resembling those of cytotoxic non-fibrogenic dusts, e.g., soluble silicas . MMA-MS particles produced low-grade fibrotic ( collagenised ) changes.

Acute Disease↗
PubMed1984

Pre- and postoperative gait analysis in patients with spastic diplegia: a preliminary report.

The benefits of using computerized gait analysis to plan and evaluate operations were assessed by studying the data from 20 children with spastic diplegia and examining the changes in estimated external work of walking, stride length, walking velocity, and joint rotations pre- and postoperatively. Of the 20 patients, 13 improved, 6 were unchanged, and 1 was worse. None of the patients walked in a crouch postoperatively. By clinical evaluation, 19 of the 20 patients were better. Thus objective gait analysis imposed much more stringent criteria for improvement. Computerized gait analysis has enabled us to be more objective in the evaluation and documentation of outcome.

Adolescent↗
PubMed1983

The origin of cholecystokinin terminals in the basal forebrain of the rat: evidence from immunofluorescence and retrograde tracing.

The origins of cholecystokinin (CCK) fibers in the olfactory tubercle, nucleus accumbens and amygdala of the basal forebrain of the albino rat were studied with combined immunofluorescence and fluorescent retrograde tracing techniques. In each case, the majority of the CCK innervation arises topographically from subpopulations of neurons in the substantia nigra-ventral tegmental area of the midbrain. This ascending CCK input to the forebrain appears to exceed the amount of descending CCK input from the cortex. In this regard, the CCK innervation of limbic structures is quite different from that of the neostriatum. It has been reported that the CCK innervation of the neostriatum is derived primarily from piriform cortex as a descending corticostriatal projection. Limbic structures, on the other hand, are primarily innervated by ascending CCK, as well as local circuit, projections.

Animals↗
PubMed1983

An investigation of fibrogenic and other toxic effects of arc-welding fume particles deposited in the rat lung.

Lung burdens of deposited particles from fumes generated by arc-welding were established in rats by single inhalation exposures, repeated intermittent exposure or by intratracheal injection. Fumes from manual metal arc-welding using flux-coated mild-steel rods (MMA-MS) were compared with those from metal inert-gas welding with stainless steel wire (MIG-SS). After initial rapid clearance of deposited material from the lungs, persistent residual deposits remained. Such residues resulting from single inhalation were small and confined mainly to peribronchial accumulations in macrophage clusters. Deposits remaining after repeated inhalation were larger and more widespread. Intratracheal administration (50 mg) established massive residual deposits, giving nodular accumulations in peribronchial, subpleural and perivascular sites, with substantial alveolar parenchymal involvement. Deposits from both types of fumes contained predominantly iron. Particles from stainless steel also contained chromium, but concentrations of this element were low in deposits from MMA-MS fumes. MMA-MS deposits contained silica, probably amorphous. Long-term studies (up to 450 days) attempted to detect evidence of fibrosis resulting from particle burdens. Low-grade collagen fibre layers developed at margins of MMA-MS nodules. Diffuse reticulin fibre networks occurred within MIG-SS aggregates. Tissue hydroxyproline levels were increased (doubled) in lungs with intratracheal burdens of MMA-MS particles, but no significant increases resulted from MIG-SS. The major lesions were nodular aggregates of particle-laden macrophages with giant-cell formation, and alveolar epithelial thickening with atelectasis.

Aerosols↗
PubMed1982

An epidemic of Kawasaki syndrome in Hawaii.

A community-wide outbreaks of Kawasaki syndrome, apparently the first in the United States, occurred in Hawaii in the first half of 1978. Twenty-seven of the 33 cases were subjected to intensive epidemiologic and microbiologic study. Patients with Kawasaki syndrome, compared to the general population, more often had Japanese ancestry, high-income status, and possibly a history of respiratory infection in the preceding month (44%). Staphylococcus aureus was not found in high frequency in the patients (15%), and viral cultures and serologic studies, immune electron microscopy, and guinea pig and primate inoculation did not reveal a causative microorganism. Febrile illnesses in guinea pigs inoculated with a skin biopsy specimen should not be further passaged.

Child↗
PubMed1982

Specific inhibition of contact sensitivity in the guinea pig following tolylene diisocyanate inhalation.

Guinea pigs were exposed by head only inhalation for 5 h to concentrations of approximately 1 ppm of tolylene diisocyanate (TDI) and 14 days later pinnal application of TDI on 3 consecutive days was followed by a dermal application of TDI after a further 7 days. The degree of contact sensitivity, measured 24 h later, showed that prior inhalation inhibited the skin reaction to TDI but it did not change the skin reaction to chloro-dinitrobenzene (DNCB) in guinea pigs sensitised and challenged similarly with DNCB. The inhibition lasted up to 9 weeks. However, it did not occur in guinea pigs after intranasal instillation (instead of inhalation) and only occurred after oral dosage with TDI when the dose was relatively high. Treatment with cyclophosphamide before TDI inhalation reversed the inhibition of contact sensitivity, suggesting an involvement of suppressor cells.

Administration, Intranasal↗
PubMed1981

Chlamydial pelvic inflammatory disease in adolescents.

Two cases of chlamydial pelvic inflammatory disease (PID) are presented. Each was clinically assessed and followed by laboratory methods now available to practitioners. These patients presented with vaginal discharge and chronic abdominal pain. They initially had positive chlamydia cultures which became negative after treatment with tetracycline. Their chlamydia titers increased throughout the course of their disease and treatment. Patient two is a case of the Fitz-Hugh-Curtis syndrome due to chlamydia. The importance of this disease in adolescents and the potential sequelae and complications of chlamydial PID are discussed.

Adolescent↗
PubMed1981

Abnormal electrocardiographic activity revealed by isolated rat heart preparations at various times after experimental myocardial infarction.

Experimental myocardial infarction has been induced in rats by isoprenaline pretreatment and progress of the lesions has been observed histologically at intervals over a period of 6 weeks. This revealed transition from extensive ischaemic degeneration to apparently complete recovery of much of the affected muscle, leaving lesser areas of necrotic cells to become replaced by dissecting collagen-fibre scars. Isolated perfused preparations of affected and normal hearts were used to give electrocardiogram records. Oscilloscope photographs were measured. Ischaemia was associated, typically, with enlarged Q waves and decreased R and S waves, plus evidence of bundle branch block. These abnormalities abated as lesions resolved, leaving residual Q enlargement and arrhythmias, consistent with persistent scarring.

Animals↗
PubMed1981

An alternative model for the psychiatric clerkship.

Clinical clerkships in psychiatry are traditionally based on in-patient services and thus limit student exposure in the main to seriously ill psychiatric patients. Such clerkships have been criticized as having questionable relevance to the primary care careers which are increasingly selected by medical students. The present paper describes a clerkship in which half the students are taught on a traditional in-patient service while half go to a special medical-psychiatric unit. In the latter situation, medical and psychiatric patients are housed together and consultation-liaison experiences play a prominent part in the students' experience. Some comparative data are presented which suggest that the two clerkship experiences are equally satisfactory to the students. It is concluded that a psychiatric clerkship utilizing settings and experiences which are close in character to primary care is educationally feasible.

Education, Medical, Undergraduate↗