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Biomedical subjects

J Perry

Publications and source records attributed to J Perry.

At least 271 records · Page 15Linked to original sources
PubMed1977

Effect of anticonvulsants on the uptake of 5-methyltetrahydrofolic acid by the choroid plexus in rabbits.

1. The isolated choroid plexus of the rabbit takes up 5-methyltetrahydrofolate from the incubation medium. 2. Other folate analogues (pteroylglutamic acid, methotrexate, 5-formyltetrahydrofolate = folinic acid) inhibited the uptake of 5-methyltetrahydrofolate. 3. The uptake of 5-methyltetrahydrofolate was inhibited by low temperature, anaerobic conditions and dinitrophenol. 4. The anticonvulsant drugs, diphenylhydantoin and phenobarbital, had no effect on 5-methyltetrahydrofolate uptake. 5. The inhibitory effect of pteroylglutamic acid on the uptake of 5-methyltetrahydrofolate by the choroid plexus may explain the effect of long-term folic acid therapy in aggravating vitamin B12 neuropathy in pernicious anaemia.

Animals↗
PubMed1977

Abnormal folate polyglutamate ratios in untreated pernicious anaemia corrected by therapy.

The relative amounts of folate compounds having 1--3--, 4--, 5-- and 6--glutamic acid residues in the molecule were measured in red blood cells. The results were expressed in relation to methyltetrahydrofolate pentaglutamate (5-glutamic acid residues) which is the analogue present in highest concentration. When the concentration of pentaglutamate is given a value of 100 the relative concentration of folates with 1--3--, 4--, 5-- and 6--glutamic acid residues in control subjects are 48, 48, 100 and 50 respectively. In folate deficiency there is a fall in the relative amount of the short chain glutamic acid chain compounds in addition to having an overall fall in the amount of folate present, the values for 1--3, 4, 5 and 6 chain folates being 16, 14, 100 and 39. By contrast, in untreated pernicious anaemia there is an accumulation of the short chain folates as well as an overall fall in polyglutamate concentration and the relative concentrations were 72, 44, 100 and 30. Folate polyglutamate appears to be the active coenzyme and the reltive amounts of glutamic acid residues may serve to regulate the rate of enzyme activity. In pernicious anaemia the amount of enzyme is reduced and on this hypothesis the regulatory function impaired.

Anemia, Pernicious↗
PubMed1977

Preoperative and postoperative dynamic electromyography as an aid in planning tendon transfers in children with cerebral palsy.

Electromyography was used to supplement clinical evaluation in planning tendon transfers in twenty-four children with cerebral palsy. Sixteen flexible deformities of the hind part of the foot, four internally rotated lower limbs, and four flexible deformities of the forearm and wrist were studied. When deforming muscles were active exclusively in one portion of either the gait cycle or a function of an upper extremity, appropriate tendon transfers were performed. When continuous muscle activity was noted, tendon lengthening was utilized. The desired function was obtained in all twenty-four patients six months after operation.

Cerebral Palsy↗
PubMed1976

A brief program to upgrade the skills of community caregivers.

This paper describes a program to train community caregivers in mental health-related skills. The goal of the program was to enhance the participants' knowledge of family intervention techniques and to produce more favorable attitudes toward family intervention. A quasi-experimental design was used to evaluate the program and is described in detail.

Adult↗
PubMed1976

Role of vitamin B12 in folate coenzyme synthesis.

Normal red cells in man were found to contain predominantly folate pentaglutamates with smaller amounts of tetra- and hexapolyglutamates. There was no change in the type of polyglutamate present in red cells from patients with vitamin B12 deficiency and primary folate deficiency. In contrast to the fall in red cell polyglutamate concentration in vitamin B12 deficiency, there was a marked fall in short-chain folates in early folate deficiency (treated non-anaemic epileptics) and a fall in both short chain and long chain polyglutamates in patients with severe folate deficiency and megaloblastic anaemia. These differences in folate distribution within cells exclude a primary failure to transport methylfolate into cells as the lesion in vitamin B12 deficiency. The failure of folate polyglutamate synthesis in ivtamin B12 deficiency arises either from a failure to provide the proper substrate for polyglutamate synthesis or to a direct requirement for vitamin B12 for polyglutamate synthesis.

Anemia, Pernicious↗
PubMed1976

Energy cost of walking of amputees: the influence of level of amputation.

A comparison of selected gait parameters and the energy cost of prosthetic walking was made in seventy patients with unilateral traumatic and vascular amputations. Amputations above the knee, below the knee, and at the Syme's level were compared in both groups of amputees, and a control group of forty normal subjects also studied. In both groups of amputees performance was significantly better the lower the level of the amputation. When preservation of function is the chief concern, amputation should be performed at the lowest possible level.

Adult↗
PubMed1976

Electromyography before and after surgery for hip deformity in children with cerebral palsy. A comparison of clinical and electromyographic findings.

Twenty-three ambulatory children with spastic diplegic cerebral palsy were evaluated clinically and by electromyography before and after hip-muscle surgery. The stretch tests originally designed to distinguish specific muscle tightness and spasticity were found to be non-specific when tested by electromyography. Ambulatory electromyograms using needle electrodes and telemetry generally showed decreased activity in the released muscles and, on occasion, changes in activity in muscles not operated on. These unanticipated changes after release may explain some of the unpredictability of results of such procedures in cerebral palsy.

Adolescent↗
PubMed1976

Triple tenodesis of the knee. A soft-tissue operation for the correction of paralytic genu recurvatum.

There are two types of genu recurvatum: one with bone deformity, which responds well to osteotomy, and one with posterior soft-tissue laxity with secondary bone changes. To date, no reliable treatment short of arthrodesis has been effective for the second type. An operation for this type of genu recurvatum (post-poliomyelitic) is described: a soft-tissue reconstruction of the lax tissues posterior to the knee joint done in three layers. The operation was done on sixteen knees in fourteen patients, with an average follow-up of four years and three months. The average recurvatum before surgery was 42 degrees and at the time of follow-up it was 6 degrees. Preliminary surgery is often required and precise surgical technique and prolonged bracing after surgery also are needed. All but one patient was made brace-free provided the limb operated on was not flail.

Adolescent↗
PubMed1975

Experimental correction of footdrop by electrical stimulation of the peroneal nerve.

Footdrop was corrected in thirteen of sixteen patients with centrally paralyzed ankle dorsiflexor muscles who were treated by electrical stimulation of the peroneal nerve by means of surgically implanted electrodes. Four patients required surgical revision before a good result was obtained. After follow-ups of more than three years there was no evidence of any nerve damage caused by chronic electrical stimulation of the peroneal nerve.

Action Potentials↗
PubMed1975

Evolution of treatment of paralytic scoliosis at Rancho Los Amigos Hospital.

Between 1954 and 1970, 351 patients with severe paralytic scoliosis were treated at Rancho Los Amigos Hospital. During this time the treatment evolved through five stages: body cast alone, halo cast, halo cast with buttons and traction wires, Harrington instrumentation, and finally preoperative halo-femoral traction and Harrington instrumentation. Coincident with this evolution, correction improved from 20 to 57 per cent, the incidence of curve progression dropped from 38 to 0 per cent, and curve extension decreased from 25 to 0 per cent, while postoperative recumbency was reduced from one year to about three weeks. In addition, complications changed, in general decreasing except for the rate of pseudarthrosis, which remained essentially the same. Clinically significant hyperlordosis involving the thoracic and lumbar spine was seen in sixteen patients who had long fusions from the fourth cervical vertebra and above to the fourth lumbar vertebra or the sacrum.

Braces↗
PubMed1975

Analysis of knee-joint forces during flexed-knee stance.

Using an instrumented cadaver lower extremity, the forces in the quadriceps, patella, and tibia during flexed-knee stance were measured and the calculated and experimental data were found to correlate with an average discrepancy of 6 per cent. The quadriceps force required to stabilize the knee was 75 per cent of the load on the femoral head at 15 degrees of knee flexion, 210 per cent at 30 degrees, and 410 per cent at 60 degrees. Stresses at the tibiofemoral and patellofemoral joint surfaces increased in similar fashion. The quadriceps force was equivalent to 20 per cent of average maximum quadriceps strength at 15 degrees and to 50 per cent at 30 degrees, as determined from torque tests on five normal subjects.

Biomechanical Phenomena↗