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Biomedical subjects

J Perry

Publications and source records attributed to J Perry.

At least 73 records · Page 4Linked to original sources
PubMed1986

Vitamin B12 neuropathy is not due to failure to methylate myelin basic protein.

It has been proposed that the biochemical lesion in subacute combined degeneration of the cord due to vitamin B12 deficiency, is impaired methylation of residue 107 (arginine) in myelin basic protein. We have examined myelin basic protein in brains of rats in which vitamin B12 was inactivated by exposure to nitrous oxide for up to 7 days. In addition brains of fruit bats in which vitamin B12 neuropathy had been produced by feeding washed, and hence vitamin B12-free fruit, were examined. There was no difference in the methylation of arginine 107 in myelin basic protein in these animals as compared to healthy control animals. Rats given an inhibitor of transmethylation reactions (cycloleucine) showed the expected fall in methylation of myelin basic protein.

Animals↗
PubMed1986

Resection arthroplasty following infected total hip replacement arthroplasty.

Thirty-nine patients with 41 hips with resection arthroplasty for infected total hip replacement arthroplasty were evaluated for functional level and factors that contribute to that level. Eighty-three percent were either minimal community ambulators or nonambulators, and only two patients walked without assistive devices. At last follow-up, 93% of the patients had pain in their hips. The best function was obtained in patients with a healed wound and heterotopic ossification. The worst functional result was in patients with chronic drainage. Fifteen of the patients with resection arthroplasties had foot-switch studies to determine gait velocity and single-limb stance time. Ten patients also had oxygen consumption studies performed. The average gait velocity was 35 m/minute (41% of normal). The average oxygen consumption was 0.41 ml/gm (264% normal) with an average heart rate of 121. The energy consumption was greater than that recorded in patients with above-knee amputation.

Adult↗
PubMed1986

Electromyography and motion analysis of the upper extremity in sports.

This article reviews the results of studies using electromyographic recordings to determine muscle function during athletic activities. Electromyographic recordings were synchronized with high-speed film to provide information on shoulder muscle firing patterns during baseball pitching, swimming, tennis, and golf. The information obtained about the contributions of specific muscles during these activities may be useful in developing effective injury prevention and rehabilitation strategies.

Baseball↗
PubMed1986

Predictive value of manual muscle testing and gait analysis in normal ankles by dynamic electromyography.

Eight muscles about the ankle of seven normal subjects were assessed by electromyography (EMG) during manual muscle testing (MMT) and walking. Three strength levels (normal, fair, trace) and three gait velocities (free, fast, slow) were tested. The muscles studied included the gastrocnemius, soleus, posterior tibialis, flexor digitorum longus, flexor hallucis longus, anterior tibialis, extensor digitorum longus, and extensor hallucis longus. Relative intensity of muscle action was quantitated visually (using an eight-point scale based on amplitude and density of the signal). The data showed that EMG activity increased directly as more muscle force was required during the different manual muscle test levels and increased walking speeds. No MMT isolated activity to the specific muscle though being tested. Instead, there always was a synergistic response. Both the gastrocnemius and soleus contributed significantly to plantarflexion regardless of knee position. The intensity of muscle action during walking related to the manual muscle test grades. Walking at the normal free velocity (meters/min) required fair (grade 3) muscle action. During slow gait the muscle functioned at a poor (grade 2) level. Fast walking necessitated muscle action midway between fair and normal, which was interpreted as good (grade 4).

Ankle↗
PubMed1985

Effect of cobalamin inactivation on folate-dependent transformylases involved in purine synthesis in rats.

N2O oxidizes and inactivates cob[I]alamin, and animals exposed in this way serve as models for cobalamin 'deficiency'. Such animals show a fall in activity of glycinamide ribotide transformylase and a rise in that of 5-amino-4-imidazolecarboxamide ribotide transformylase. The fall in glycinamide ribotide transformylase activity was prevented by parenteral 5'-methylthioadenosine derived from methionine. Methylthioadenosine in turn is converted into formate. Activity of glycinamide ribotide transformylase recovers after 7 days despite continued N2O inhalation, and this is probably related to restoration of methionine synthesis by induction of betaine:homocysteine transmethylase.

Acyltransferases↗
PubMed1985

Folate polyglutamate synthetase activity in the cobalamin-inactivated rat.

Exposure to N2O inactivates cob[I]alamin and interferes with the activity of methionine synthetase, of which cob[I]alamin is a coenzyme. Less directly, it stops the formation of folate polyglutamate from tetrahydrofolates. Studies on the activity of folate polyglutamate synthetase in rat liver in vivo were carried out. The synthetase activity increased after exposure to N2O for up to 48 h, but longer exposure was accompanied by a return of activity to baseline values. The rise in synthetase activity was prevented by supplying methionine, 5'-methylthioadenosine or 5-formyltetrahydrofolate. The fall in folate polyglutamate synthetase activity after 48 h was accompanied by a restoration of hepatic synthesis of folate polyglutamate despite continuation of N2O exposure.

Amide Synthases↗
PubMed1985

Induction of IgA-specific suppressor activity in human T-lymphocyte cultures.

Cell-free supernatants of human circulating T-lymphocyte cultures incubated with secretory IgA (S-IgA) specifically suppressed both spontaneous IgA synthesis by B lymphocytes isolated from allergic individuals and pokeweek mitogen-induced IgA secretion by peripheral blood mononuclear cells. Cell-free supernatants of T-cell cultures incubated with IgE had no effect on IgA, IgG, or IgM synthesis. Hence, it is concluded that upon incubation with S-IgA, but not with another Ig class, T lymphocytes release IgA-specific suppressor factors.

Antibody Specificity↗
PubMed1985

Surreptitious warfarin ingestion.

Munchausen by proxy has been reported involving children who have been given various drugs or toxins. In addition, there is a body of adult literature regarding covert anticoagulant ingestion. This is a case of an 11-month-old female who appears to combine features of both of these syndromes. This child presented with an acute left hemorrhagic otitis media. The physical examination was unremarkable except for the following: weight, fifth percentile; left external auditory canal filled with blood with the right external canal and tympanic membrane being normal; and several scattered 1 X 2 cm firm, movable, nontender, purple nodules on extremities, chest and forehead. The coagulation studies were consistent with Vitamin K deficiency secondary to anticoagulant ingestion. A serum warfarin study confirmed our suspicions. The mother was noted to have a dependent relationship with her child and characteristics of those involved in Munchausen by proxy: falsifying information and thwarting medical assessment. In addition, she displayed some of the characteristics found commonly in anticoagulant malingerers. She was depressed, with limited medical knowledge, and had access to warfarin. The mother was admitted for inpatient psychiatric care and the patient placed with an extended family member. This case report describes the use of an anticoagulant to induce illness in a child by a psychologically ill mother. This form of child abuse must be considered in the differential diagnoses of hemorrhagic disorders.

Adult↗
PubMed1985

Rising from a chair. Influence of age and chair design.

We studied the effect of age on the act of rising from a standard armchair in a younger (means = 24 years) and an older (means = 75 years) group of healthy adult women. Rising from a standard armchair and an armchair specially designed for comfort in sitting of the elderly was studied in the older group to determine the influence of the special chair. We used electrogoniometry, EMG, and videotape analysis to record the activity for both groups. The older group placed their feet farther back and showed greater vastus lateralis muscle activity than did the younger group to rise from the standard chair. These results suggest that rising from the standard chair was more difficult for the older than for the younger group. In the special chair, the older subjects showed even more vastus lateralis muscle activity, greater knee flexion, and greater trunk forward lean. Rising from the special chair, therefore, appeared to be more difficult than rising from a standard chair; this finding suggests that both comfort and function must be considered in chair selection for certain groups.

Adult↗
PubMed1985

Walking patterns of healthy subjects wearing rocker shoes.

We compared walking in rocker shoes with walking in athletic shoes at free and fast velocities in 15 healthy women who were between the ages of 21 and 30 years. Footswitches, electrogoniometers, surface electromyograms, and a force plate were used for data collection. No significant differences were found in velocity, cadence, gait-cycle duration, single-limb support, or swing-stance ratios in free and fast walking. Double-limb support was decreased by 9% in the rocker shoes in free walking. The ankle range of motion showed accommodation of the foot to the 8.5 degrees of plantar flexion built into the rocker shoes. Electromyographic responses appeared to be similar regardless of shoes or cadence.

Adult↗
PubMed1985

Rate and range of knee motion during ambulation in healthy and arthritic subjects.

The purpose of this study was to determine the relationship between gait velocity and rate and range of knee motion, during ambulation, for healthy and arthritic subjects. The arthritic subjects had either rheumatoid arthritis or osteoarthritis, and all were tested before and after total knee replacement. Healthy subjects ambulated at an average velocity of 80 m/min and demonstrated knee flexion and extension rates of 344 degrees/sec and a range of knee motion of 60 degrees. Gait velocity correlated with rates of knee flexion and extension and range of knee motion. Arthritic subjects ambulated at velocities less than those of healthy subjects ambulating at free speed. Arthritic subjects accordingly demonstrated reduced knee flexion and extension rates and range of knee motion. When compared with healthy subjects ambulating over a comparable gait-velocity range, the arthritic subjects demonstrated reduced rates and range of motion in most instances. We discuss implications for therapeutic intervention to increase gait velocity for arthritic subjects.

Adult↗
PubMed1985

Has the discipline of nursing developed to the stage where nurses do 'think nursing'?

With the increasing complexity and changing conditions of nursing practice, as well as the encroachment of other professions on nursing's traditional domain, it is becoming increasingly important for nurses to gain insights into the nature of nursing knowledge and practice. This paper attempts to outline the meaning of the expression 'to think nursing' and the factors involved in such a capacity. The work of nurse scholars is then discussed in terms of their contribution towards developing the discipline of nursing to the stage where nurses do 'think nursing'.

Attitude↗
PubMed1985

Role of folate dependent transformylases in synthesis of purine in bone marrow of man and in bone marrow and liver of rats.

The activity of the two folate dependent enzymes supplying carbon 2 and carbon 8 of the purine nucleus was assayed in the bone marrow of rats and man, as well as in rat livers. The activity of both enzymes was several fold greater in marrow than in liver. Inactivation of cobalamin by exposure to nitrous oxide did not affect the enzymes in rat marrow cells, although an appreciable effect on hepatic enzymes was found. The depression of hepatic glycinamide ribotide (GAR) transformylase in rats exposed to nitrous oxide was prevented by supplying a formate precursor, methylthioadenosine. There was a considerable rise in the activity of GAR transformylase in human marrow cells from patients with megaloblastic anaemia due to cobalamin deficiency but no change in activity in marrow from patients deficient in folate.

Acyltransferases↗
PubMed1985

Functional demands on the stance limb in walking.

In normal human locomotion, the lower extremities must maintain the erect posture while at the same time permitting forward progression of the body. Walking involves a complex interplay of gravity, momentum changes, and muscle action. A quantitative analysis of the effects of gravity and momentum changes on the stance limb in normal gait has been performed. These effects, represented by the ground reaction force, impose challenges to the muscles of the lower extremity. The nature of the torques about the hip, knee, and ankle joints has been investigated and correlated with the timing of muscle action throughout the gait cycle. Mechanical events in the earliest part of stance phase have been more clearly described than in previous work. Analysis of the effects of gravity and momentum changes improves our understanding of the mechanics of normal walking, and can aid in the diagnosis and treatment of disabled patients.

Adult↗
PubMed1985

Polio: long-term problems.

The most common long-term problems seen in polio are brace problems, knee recurvatum, increasing weakness due to overuse and ankle equinus. A definite increased incidence of problems is seen after the patient is more than 30 years post-polio. The basis for most of these problems is chronic mechanical strain of weak musculature and substituting ligaments. Overuse can cause increasing weakness resulting in pain and decreasing function. It is therefore important to follow polio patients closely, especially those that are more than 30 years post-polio. If signs of overuse or chronic mechanical strain are noted, treatment should not be delayed.

Adolescent↗
PubMed1985

Functional evaluation of total hip arthroplasty with five- to ten-year follow-up evaluation.

Forty-seven patients with unilateral hip disease had a preoperative and postoperative gait analysis of total hip arthroplasty with a follow-up period of five to ten years. The object was to correlate the levels of function with mechanical loosening. Unilateral total hip arthroplasty in uncomplicated patients restored function to 80% of normal over a two- to four-year period. Patients followed longer than five years appeared to have an accelerated decline in function unassociated with pain. No Class C patient, regardless of age or gait velocity, developed loosening or required revision of the hip prosthesis. Survivorship studies revealed an 85%-90% incidence of loosening by the seventh postoperative year in Class A patients 55 years or younger and those walking preoperatively at more than 50% of normal gait velocity. In these same two groups of patients, the probability of revision for mechanical failure by ten years is 58% for age and 66% for fast walkers. The majority of patients in this study had a technical rating not acceptable by present standards so that these results represent most likely the worst prognosis for longevity of total hip arthroplasty. In high-risk patients, protected ambulation with crutches for six months postoperation may improve their prognosis.

Female↗