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Biomedical subjects

H J Roberts

Publications and source records attributed to H J Roberts.

At least 55 records · Page 3Linked to original sources
PubMed1983

Potential toxicity due to dolomite and bonemeal.

Large amounts of dolomite and bonemeal are being consumed, especially by nutrition-conscious persons. The mineral content of commercial samples has been analyzed by different laboratories, and significant amounts of lead, arsenic, mercury, and other potentially toxic metals, which also exist in conventional vitamin-mineral and calcium supplements, were detected. Physicians must consider the possibility of unrecognized self-poisoning from the consumption of such substances, especially in the context of unexplained neurologic, gastrointestinal, cutaneous, and hematologic disorders. The use of dolomite and bonemeal by pregnant women, children with suspected milk allergy, and elderly persons requires careful evaluation.

Adult↗
PubMed1982

Early life undernutrition and operant responding in the rat: the effect of the reinforcement schedule employed.

Rats were either undernourished from birth to 43 days and thereafter well fed (previously undernourished, PU) or well nourished throughout. When behaviour was tested in adulthood it was found that significant differences between the groups in rate of lever-pressing for food occurred when they were tested under a variable-interval 60-sec schedule of reinforcement, but not when reward was delivered according to a fixed-interval 60-sec or variable-ratio ten schedule. The results of a second experiment suggested that the rate difference might reduce or disappear with extended exposure to the schedule. The third experiment exposed rats to fixed-interval 60-sec and mixed fixed-interval 10-sec fixed-interval 110 sec schedules. Response rate differences between the PU and control groups occurred only under the mixed schedule, a result interpreted as showing that temporal irregularity of reward delivery plays some role in the genesis of more rapid operant responding in PU rats. When rats received a larger variable-ratio schedule, requiring 40 responses for reward, no significant rate differences between the groups were found over the whole experimental condition. It is suggested that schedules on which there are significant differences have some special characteristic, possibly sensitivity to differences in food motivation between the groups.

Animals↗
PubMed1982

Timed repetitive ankle jerk responses in early diabetic neuropathy.

A 14-year experience with timed repetitive ankle jerk (TRAJ) testing provides fundamental insights into diabetic neuropathy (DN), both its diagnosis and treatment. Advantages of TRAJ include ease of performance, relative economy of the equipment, reproducibility of results, and a parameter that encompasses the entire reflex arc. Euthyroid patients with features suggesting DN often have prolongation of ankle jerk responses on one or both sides only after repetitive stimulation. Prolongation of TRAJ responses were elicited from 41% of overt diabetics and from 27% and 30% of patients with decreased glucose tolerance demonstrated by morning or afternoon testing, respectively. This characteristic response appears to reflect altered neuromuscular function in DN and was not encountered in patients with myasthenia gravis or thyroid dysfunction in the absence of concomitant glucose metabolic aberrations.

Adult↗
PubMed1980

Controversies and enigmas in thrombophlebitis and pulmonary embolism. Perspectives on alleged overdiagnosis.

Increased criticism concerning the alleged misdiagnosis and overdiagnosis of deep vein thrombophlebitis (DVT) in the lower extremities, and of pulmonary embolism is being leveled at clinicians when unequivocal documentation by venography, lung scanning, and pulmonary angiography is lacking. The excessive adoption of this attitude by audit and utilization committees could prove dangerous for patients with these conditions, particularly when rigid criteria intimidate the physician and override his clinical judgment and experience. The matter assumes added importance in view of the increasing magnitude of DVT and pulmonary embolism. The following pertinent issues will be discussed: 1. Failure to consider DVT and pulmonary embolism in the appropriate clinical settings, especially when they are still minor and atypical. 2. Deficiencies in the physical examination. 3. Failure to recognize the inherent limitations of existing diagnostic methods. 4. The perpetuation of diagnostic bias and dogma by teachers and the literature. 5. Confusion introduced by coexisting disorders. The combination of these insights, greater confidence in clinical skills, and newer noninvasive diagnostic methods promise to help resolve this heated controversy.

Adult↗
PubMed1979

Thrombophlebitis associated with vitamin E therapy. With a commentary on other medical side effects.

I have encountered 50 patients with clinical thrombophlebitis involving the lower extremites, with or without associated edema and pulmonary embolism, in whom longstanding self-medication with large amounts of vitamin E appeared to be a significant factor. The majority improved following cessation of vitamin E. In view of the epidemic nature of thrombophlebitis and deep vein thrombosis in the United States, the presumed innocuousness of vitamin E therapy requires reevaluation. Other clinical side effects also have been noted in patients receiving large doses of vitamin E. They include breast tenderness, elevation of blood pressure, a fatigue syndrome, myopathy, intestinal cramps, urticaria, and the possible aggravation of diabetes mellitus. The influence of concomitant metabolic, endocrine, and cardiovascular disorders on the thrombogenic potential of vitamin E is raised, and several possible mechanisms conducive to thrombophlebitis are reviewed.

Adult↗
PubMed1979

Transcutaneous electrical nerve stimulation in the symptomatic management of thrombophlebitis.

Transcutaneous electrical nerve stimulation (TENS) afforded significant relief of the pain associated with acute and recurrent thrombophlebitis in 90% of 39 patients so treated. The method is simple to administer, noninvasive, and apparently free of side effects. It can be self-administered by the patient after appropriate instruction. TENS can be given in conjunction with analgesics, anticoagulant therapy, and other supportive measures to achieve greater relief and mobility in patients with thrombophlebitis whose occupations and other activities are severely limited by their pain. Further clinical trials involving larger numbers of patients, and clarification of the analgesic mechanisms involved, are warranted because of the magnitude of this problem. TENS therapy can be uniquely beneficial in certain clinical situations. They include the contraindication of conventional treatments for the pain of thrombophlebitis, pelvic vein phlebitis, and the presence of concomitant painful orthopedic and neurologic disorders.

Adult↗
PubMed1978

Transcutaneous electrical nerve stimulation in the management of pancreatitis pain.

The application of transcutaneous electrical nerve stimulation (TENS) to the abdomen produced prompt and sustained relief of the pain associated with pancreatitis in five patients and in another patient with probable acute pancreatitis. The disorder was acute in two patients and recurrent in four. Multiple hospitalizations, including the need for analgesics and opiates, had been required during previous attacks in five patients. In view of the simple and noninvasive nature of such treatment, more extensive clinical trials appear to be warranted. Some of the possible mechanisms of action for TENS analgesia are reviewed.

Acute Disease↗
PubMed1978

The noninvasive diagnosis of thrombophlebitis in the lower extremities: clinical value of plethysmography combined with augmentation methods and a new scoring system.

Venous impedance plethysmography and respiratory-compression Doppler augmentation responses have proved to be diagnostically valuable in suspected thrombophlebitis of the lower extremities. These noninvasive methods can provide quantitative and reproducible data on the basis of which the presence of increased deep venous resistance can be confirmed, suspected, or doubted. A new scoring system for the composite evaluation of data from 100 consecutive patients with possible thrombophlebitis, pulmonary embolism, or both, is presented. These procedures assume added importance in view of the diagnostic limitations, and even potential hazards, of other methods. These methods indluce lung scanning, radioactive fibrinogen scanning, venography, and pulmonary angiography. Serial studies can be performed with impunity for following highrisk patients and evaluating various therapeutic or prophylactic measures. The importance of monitoring the femoral-popliteal segment is emphasized, because of the greater propensity for massive pulmonary thromboembolism from thrombi in these veins than in the calf vessels. Clinical observations coupled with these studies underscore the fallacy of several widely-held diagnostic biases pertaining to deep venous thrombosis and pulmonary thromboembolism. The long-term followup of 12 patients in whom inferior vena cava unbrellas has been inserted for life-threatening pulmonary embolism is presented. The possible propensity to deep vein thrombosis from vitamin E therapy is raised.

Adult↗