PubMed Health⌕ Search

Biomedical subjects

J Perry

Publications and source records attributed to J Perry.

At least 235 records · Page 13Linked to original sources
PubMed1983

Increased urinary excretion of formiminoglutamic acid in nitrous-oxide-treated rats and its reduction by methionine.

Inhalation of nitrous oxide oxidises cob(I)alamin and inactivates methionine synthetase of which cobalamin is a co-enzyme. The biochemical changes in the rat following exposure to nitrous oxide resemble in some detail the changes present in patients with untreated pernicious anemia due to deficiency of cobalamin. There is a marked increase in the excretion of formiminoglutamic acid in the urine following exposure to nitrous oxide. A significant decrease is produced, while on N2O, by giving methionine. The explanation for these findings is discussed in the light of recent data on the effects of cobalamin inactivation.

Animals↗
PubMed1983

Comparative cost of walking in young and old adults.

Normative data that summarize the energy requirements and gait characteristics of level outdoor walking were determined in 111 normal subjects between the ages of 20 and 80 years. Subjects were divided into two age groups: young adults (20-59 years) and senior subjects (60-80 years). The mean rate of oxygen consumption for young adults and senior subjects did not significantly differ, averaging 11.9 ml/kg-min for both groups. The data on heart rate paralleled the findings on oxygen consumption, averaging 100 and 103 beats/min, respectively. The net oxygen cost per meter walked for senior subjects, 0.16 ml/kg-m, was significantly greater (p less than 0.0005) than the value for young adults, 0.15 ml/kg-m, due to a decline in the average walking speed. The average gait velocity for senior subjects, 73 m/min, was statistically significantly less (p less than 0.0005) than the values for the younger adults, 80 m/min.

Adult↗
PubMed1983

Timing and relative intensity of hip extensor and abductor muscle action during level and stair ambulation. An EMG study.

The timing and relative intensity of electromyographic activity of hip abductor and extensor muscles were recorded during free and fast velocity walking and during ascent and descent of stairs. Eleven healthy subjects were tested using fine wire electrodes to record the electromyographic activity. Data were quantified by normalizing all electromyographic activity during gait with electromyographic activity occurring during a sustained maximum isometric effort resisted either manually or with a dynamometer. The results indicated that the hip extensor muscles had different phasic patterns and moments of peak activity. During level walking, the semimembranosus and long head of the biceps femoris muscles displayed the greatest swing phase activity (beginning in mid-swing). The adductor magnus muscle followed with its onset in terminal swing. Both this muscle and the gluteus maximus were the principal hip extensors active during the loading response. For ascending stairs, the lower portion of the gluteus maximus muscle proved to be the main hip extensor during the loading response and mid-stance. The findings also showed that the upper portion of the gluteus maximus muscle functioned more like the gluteus medius muscle than the lower portion of the gluteus maximus muscle during both level and stair walking.

Adult↗
PubMed1983

Use of the Phoenix system for bacteriology.

A dedicated microbiology data processing system with remote batched job entry to an obsolete computer, has been superseded by the inclusion of bacteriology in an on-line interactive clinical pathology system which had previously incorporated chemical pathology and haematology. The original Phoenix system has been adapted to allow for the entry of bacteriology data using mnemonic codes and to deal with the problems caused by the longer processing time of bacteriology specimens. Particular advantages of the new system include the immediate linkage of all specimens for each patient and an easy recall and display of results in the laboratories and on the wards.

Bacteriology↗
PubMed1983

Chronic cobalamin inactivation impairs folate polyglutamate synthesis in the rat.

Nitrous oxide, by inactivating cobalamin in vivo, produces a suitable animal model for cobalamin 'deficiency.' The synthesis of folate polyglutamate with tetrahydrofolate as substrate is severely impaired in the N2O-treated rat, but is normal with formyltetrahydrofolate as substrate. Methionine restores the capacity of the N2O-treated rat to utilize tetrahydrofolate the minimum effective dose being 16 mumol. S-Adenosylmethionine was somewhat less effective than methionine but 5'methylthioadenosine, a product of S-adenosylmethionine metabolism, was significantly more effective than methionine in correcting the defect in folate polyglutamate synthesis. 5'Methylthioadenosine is metabolised to yield formate. It is suggested that these compounds have their effect in correcting folate polyglutamate synthesis by supplying formate for the formylation of tetrahydrofolate. Formyltetrahydrofolate, at least in the cobalamin-inactivated animal, is the required substrate for folate polyglutamate synthesis. Cobalamin is concerned with the maintenance of normal levels of methionine and this in turn is a major source of formate through S-adenosylmethionine and 5'methylthioadenosine.

Adenosine↗
PubMed1983

Rehabilitation of the neurologically disabled patient: principles, practice, and scientific basis.

Rehabilitation is a therapeutic program specifically directed toward restoring the optimum level of function available to patients with severe permanent disabilities. It complements standard care, which focuses on curing the primary pathology. Preventive rehabilitation is designed to minimize the complications of inactivity that tend to develop during a protracted curative process (contractures, pressure sores, muscle atrophy, cardiopulmonary deconditioning, cognitive dulling). Comprehensive rehabilitation focuses on the restoration of function. It encompasses physical reconditioning, teaching new ways to accomplish the basic tasks of locomotion, object handling, personal care, relationships with family and society, employment, and recreation. The rehabilitation program is largely designed and provided by a team of allied health professionals, each an expert in one area of function. Reverting to a less dominant role, the physician provides leadership by defining the stress (activity) tolerance of the patient's pathology, coordinates the team, and manages intercurrent problems that arise. Comprehensive rehabilitation is an in-hospital program. Less intense elements can be provided in a skilled nursing facility, out-patient clinic, or the patient's home. The details of the rehabilitation process vary with the nature of the patient's primary pathology. These have been illustrated in this review of the programs for two very diverse situations. Spinal cord injury introduces varying levels of physical incapacitation. Conversely, brain injury primarily creates a cognitive and behavioral deficit. Both are complex problems requiring comprehensive rehabilitation if the impairment is severe.

Brain Injuries↗
PubMed1983

Lower extremity electromyographic analysis of running gait.

Onset of firing for the quadriceps, hamstrings, and gastroc soleus groups during running, both on a treadmill and over ground, was determined in seven normal adult male subjects. Surface and wire electrode data were collected simultaneously from 959 individual gait cycles. The mean velocity over ground was 274 +/- 38 m/minute, with a mean cadence of 171 +/- 14 steps/minute. The treadmill was set at 107 m/minute (4 miles/hour), and the subjects' mean cadence was 147 +/- 11 steps/minute. Over ground, the mean swing/stance ratio was 70/30 +/- 3%, and that for the treadmill was 60/40 +/- 6%. Like muscle groups on the right and left showed a mean difference in onset of muscle activity of 1.3% (+/- 4.6%) when measured during a minimum of ten cycles per subject for each test condition. The average difference in time of onset between the surface and wire electrodes was 2% (SD +/- 4.9%) on the treadmill and 1.5% (SD +/- 3.7%) for over-ground running. These differences are not statistically significant. Surface and wire electrode data have been determined to be equivalent only for regional synergistic muscle groups and should not be extrapolated to compare functions of individual muscles within those groups.

Adult↗
PubMed1983

Adduction contracture of the thumb in cerebral palsy. A preoperative electromyographic study.

In twenty-three patients with cerebral palsy and functional spastic hemiplegia, the contracted thenar-adductor space of the involved hand was evaluated by electromyography. The needle electromyogram was used to determine if the patient had selective control of the adductor muscle. In eight patients only partial myotomy of the adductor muscle during z-plasty of the web was performed because selective control of that muscle was present during either grasp or release. In four patients a complete release was done, and in two of them the ability to pinch was impaired.

Adolescent↗
PubMed1983

Anatomy and biomechanics of the shoulder in throwing, swimming, gymnastics, and tennis.

As the most mobile joint in the body, the shoulder is structurally insecure. The ball-shaped humeral head rotates and glides on a shallow scapular cup. A limited amount of passive stability is provided by the glenoid labrum, which slightly deepens the scapular cup, and by ligaments reinforcing the capsule on its superior and anterior surfaces. At peak maturity ligamentous restraint equals 50 to 80 kg. These structural limitations indicate that the primary source of joint stability must be balanced muscle control. Joint compression is the major factor. This is supplemented by active tangential restraint, which selectively opposes anterior, posterior, or superior displacement. The large external muscles used for purposeful motion and speed often create subluxating shear forces in addition to the desired actions. Impingement and attrition syndromes are common consequences. To counter this, as well as to provide selective rotation, there are the four muscles that constitute the rotator cuff. Joint compression is the major force generated by the supraspinatus and infraspinatus. The latter (accompanied by the teres minor) also provides a downward pull to oppose the upward displacement of early deltoid action. Anterior protection against excessive external rotation or extension is offered by the subscapularis. Athletic who use the arm for a propelling force strain the extremes of joint range in their drive for maximum performance. The threat of injury can be minimized by two actions, namely, modifying motion patterns, which may avoid impingement or make it a less frequent experience, and active protection, which is gained through specific strengthening of the rotator cuff muscles.

Athletic Injuries↗
PubMed1982

Stereotactic surgery using the "therapeutic" CT scanner.

Computerized tomography (CT) has become the natural imaging partner during stereotactic brain operations. At last a radiographic technique has been developed that actually visualizes the target and surrounding brain. Used intraoperatively, CT confirms accurate position of the probe, monitors biopsy or lesion techniques, immediately assesses results, and reduces the risks of operative complications. When appropriate markers are provided in the CT image, the CT computer rapidly generates target coordinates by converting CT coordinates to stereotactic frame coordinates. The same CT computer can be used to preselect the best trajectory and preplot the probe's path before insertion, using each patient's own "CT brain map." An accuracy of 1 mm has been achieved. The range and purpose of using an integrated CT-stereotactic system in the assessment of 11 patients with deep brain lesions is described. Operations are performed with the patient placed in the CT scanner. The stereotactic frame, constructed with low-atomic-number materials, permits nearly artifact-free CT images. With this stereotactic approach, CT has become part of the surgical armamentarium. Stereotactic surgery will soon be performed in an operating room equipped with such a "therapeutic" scanner.

Adolescent↗
PubMed1982

A comparison of tetrahydrofolate and 5-formyltetrahydrofolate in correcting the impairment of thymidine synthesis in pernicious anaemia.

5-formyltetrahydrofolate and tetrahydrofolate were added to marrow cells from patients with untreated pernicious anaemia at 1, 5 and 50 nmol doses in the deoxyuridine suppression test. At all 3 dose levels formyltetrahydrofolate was significantly more effective in correcting the defect of thymidine synthesis in pernicious anaemia, than tetrahydrofolate. The data suggest that formylation of tetrahydrofolate is necessary for its normal utilization.

Anemia, Pernicious↗
PubMed1982

Electromyographic gait analysis before and after operative treatment for hemiplegic equinus and equinovarus deformity.

Gait electromyograms were obtained before and after tendon transfer, lengthening, or release in twenty-seven hemiplegic patients with equinus or equinovarus deformities. Abnormal patterns of muscle activity almost always were present preoperatively in the gastrocnemius, soleus, tibialis posterior, flexor hallucis longus, flexor digitorum longus, peroneus brevis, and tibialis anterior muscles in these patients. The surgical procedures to correct the foot deformities altered the gross patterns of activity of most of the muscles operated on by very little. Of particular importance to the surgeon was the finding that the pattern of activity of the muscles whose tendon was transferred, lengthened, or released was not altered after operation. This finding makes the preoperative gait electromyogram a useful means of determining the appropriate surgical plan, since it is an indication of the type of muscle activity to expect postoperatively.

Adult↗
PubMed1982

Urinary folate loss following inactivation of vitamin B12 by nitrous oxide in rats.

Rats were injected with [2-14C]H4PteGlu daily for 3 d and thereafter one group left in air and a second group in an atmosphere of nitrous oxide/oxygen (1/1). Nitrous oxide inactivates cobalamin. The N2O-treated rats excreted large amounts of L. casei-active folate into the urine. The urinary folate co-chromatographed with authentic 3H-labelled 5-methyltetrahydrofolate. Both groups of animals excreted 14C-labelled breakdown products in the urine but there was no evidence of increased folate catabolism in the N2O-treated rats. It was concluded that the folate deficiency that develops in the N2O-treated rat is due to massive urinary loss of folate. This appears to be secondary to impaired cellular uptake of folate which leads to a raised plasma folate level.

Animals↗
PubMed1982

The functional cost of dislocation following total hip arthroplasty.

The consequences of dislocation following total hip arthroplasty were assessed using quantitative gait analysis. As a preliminary study, a review of 18 patients having undergone hip arthroplasty without dislocation provided as understanding of the improvement in gait in the first two years after surgery. Seven patients with a single dislocation and six patients with multiple dislocations were compared with patients matched according to age and preoperative gait characteristics and who experienced an uncomplicated recovery following hip arthroplasty. One year after surgery patients with a single dislocation could not be differentiated from the matched patients with respect to gait velocity and single limb support time. However, patients, with multiple dislocations walked significantly slower and had a significantly decreased single limb support time in the involved extremity than their respective matched patients.

Aged↗
PubMed1981

Changes in tissue folates accompanying nitrous oxide-induced inactivation of vitamin B12 in the rat.

The anesthetic gas, nitrous oxide, oxidizes cob(I)alamin and thus inactivates methionine synthetase which requires cobalamin as a coenzyme. The effect on folates in liver, kidney, marrow, plasma, and brain in rats breathing a 1/1 nitrous oxide/oxygen mixture is described. There is loss of folate from tissues, most marked in liver, that affects folate polyglutamates to a greater extent than folate monoglutamates. Both methyl- and nonmethyl-analogues are affected. There is a transient rise in the levels of 5-methyltetrahydropteroylpolyglutamate in all tissues 8 h after starting nitrous oxide, which falls thereafter. In marrow and brain there is also a transient rise in methyltetrahydropteroylmonoglutamate. Plasma folate increased markedly throughout the period of exposure to nitrous oxide. It is suggested that these changes are due to the action of nitrous oxide in depressing tissue uptake of folate from plasma, in promoting loss of folate into urine and in inhibiting folate polyglutamate synthesis.

Animals↗