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Biomedical subjects

J Perry

Publications and source records attributed to J Perry.

At least 19 recordsLinked to original sources
PubMed1992

Evaluation of a prolonged infusion of recombinant tissue-type plasminogen activator (Duteplase) in preventing reocclusion following successful thrombolysis in acute myocardial infarction.

The hypothesis that an infusion of recombinant tissue-type plasminogen activator (rt-PA) maintained for up to 24 hours could prevent reocclusion after early coronary patency had been established was evaluated in patients with acute myocardial infarction. The rt-PA studied was an investigational double chain rt-PA (Duteplase, Burroughs Wellcome Co.), administered according to body weight. Coronary patency was documented in 139 of 213 patients who had 90-minute angiograms recorded after an initial lytic dose of rt-PA. In these responders a further 90-minute infusion at one third the initial lytic dose was given before assignment to 1 of 4 maintenance dose rates (0.012, 0.024, 0.036, 0.048 MIU/kg/hour) which were continued for the subsequent 9 to 21 hours. The principal end point was the status of the infarct-related coronary artery 12 to 24 hours after the start of therapy, and before termination of rt-PA, in patients with initially patent vessels at 90 minutes. Of the 103 responders with repeat angiograms after a 9 to 21 hour maintenance infusion of rt-PA, a total of 17 (16.5%) patients reoccluded across all doses administered. There was no significant relationship between the maintenance dose rate and the incidence of reocclusion. However, there was strong association between total dose of rt-PA administered and the incidence (16%) of serious or life-threatening bleeding exclusive of surgery. Other factors associated with serious bleeding included low body weight, female gender, and total duration of rt-PA infusion. Reocclusion was independent of the 90-minute Thrombolysis in Myocardial Infarction trial perfusion grade and diameter of infarct vessel. Rethrombosis after establishment of early patency after rt-PA remains a significant problem that is unaffected by sustained rt-PA infusion in doses that can be tolerated.

Female↗
PubMed1992

An electromyographic analysis of the shoulder during cones and planes of arm motion.

Shoulder motion has traditionally been described in reference to arbitrarily defined planes of motion (e.g., sagittal/flexion, coronal/abduction). This study examined shoulder muscle recruitment during conical arm movements, which include all planes of motion. Electromyographic (EMG) data was collected with intramuscular wire electrodes from ten muscles in five normal volunteers. Each muscle showed peak EMG activity in association with a direction of action consistent with its anatomic alignment. These findings were similar for movements in both the sagittal and coronal planes, calling into question conventionally held designations of shoulder muscles as flexors and abductors. Muscle recruitment was as follows: Clavicular pectoralis major, to move the arm medially along the horizontal; anterior deltoid, to move the arm obliquely upward inclined toward the midline; middle deltoid, to move the arm obliquely upward inclined away from the midline; posterior deltoid, to move the arm laterally along the horizontal; and teres major and latissimus dorsi, to move the arm obliquely downward away from the midline. Rotator cuff muscles were maximally active during elevation, consistent with the concept of a force couple.

Adult↗
PubMed1992

Computer algorithms to characterize individual subject EMG profiles during gait.

Three methods of precisely determining onset and cessation times of gait EMG were investigated. Subjects were 24 normal adults and 32 individuals with gait pathologies. Soleus muscle EMG during free speed level walking was obtained with fine wires, and was normalized by manual muscle test (%MMT). Linear envelopes were generated from the rectified, integrated EMG at each percent gait cycle (%GC) of each stride in individual gait trials. Three methods were used to generate EMG profiles for each tested subject. The ensemble average (EAV) was determined for each subject from the mean relative intensity of the linear envelopes. Low relative intensity or short duration EMG was removed from the ensemble average to create the intensity filtered average (IFA). The packet analysis method (PAC) created an EMG profile from the linear envelopes in successive strides whose respective centroid %GC locations were within +/- 15%GC of each other. Control values for onset and cessation times of individual gait trials were calculated after spurious outliers were removed. Mean onset and cessation times across subjects for control values and the experimental methods (EAV, IFA, and PAC) were calculated. Dunnett's test (p less than .05) was performed to compare control and experimental groups in patient and normal trials. EAV differed from control values for onsets (p less than .01), cessations (p less than .01), and durations (p less than .01) in both normal and patient trials. IFA and PAC had no significant differences from control value means. IFA was selected for clinical use as automatic analysis could be performed on all trials and a minimum number of decision rules were needed.

Adult↗
PubMed1991

Chemotherapy of disseminated Merkel-cell carcinoma.

Six patients developed metastatic merkel-cell carcinoma and were treated with a combination chemotherapy frequently used for small-cell lung cancer. Five of six patients had a complete response for a median of 3.5 months. Overall survival from initiation of chemotherapy was a median of 6.5 months. Two patients died from major complications of therapy.

Adult↗
PubMed1991

Stiff-legged gait in spastic paresis. A study of quadriceps and hamstrings muscle activity.

Stiff-legged gait, ascribed to limited knee flexion during swing in spastic paresis, has previously received little detailed investigation. In this study, data from 23 patients referred for dynamic electromyographic evaluation of spastic stiff-legged gait were analyzed to identify timing of the activity of eight muscles during the gait cycle. Stride characteristics and foot switch data were also analyzed. Inappropriate activity in at least one of the quadriceps muscles during the preswing and/or initial swing phases was found in all 23 patients. Nine patients (39%) had hamstring activity during preswing. This group of 9, compared with the other 14 patients, had a significant reduction in average gait velocity and stride length (P less than 0.05) suggesting that preswing hamstring activity in stiff-legged gait may be counterproductive. No relation was found between biceps femoris (short head) activity and the amount of peak knee flexion attained in swing indicating that other factors are more important in attaining knee flexion. Delayed heel rise was observed in 21 patients (91%), which could imply insufficient calf muscle strength. Further, patients with markedly delayed heel rise achieved less peak knee flexion in swing than patients with normal or only moderately delayed heel rise (P less than 0.05). This may support the notion that adequate calf muscle strength is important in initiating knee flexion in the terminal stance/preswing phase. Results from this study provide preliminary quantitative information about stiff-legged gait that may prove useful in guiding management techniques.

Adult↗
PubMed1991

Cocaine in decomposed human remains.

From March 1988 through March 1990, at the Philadelphia Medical Examiner's Office toxicology laboratory, samples from 77 decomposed human bodies were tested for the presence of cocaine, employing gas chromatography/mass spectrometry (GC-MS). The material analyzed included decomposed soft tissue, bloody decomposition fluid, mummified tissue, maggots, and beetle feces. Twenty-two cases (28.6%) were positive for cocaine, many of these cases in states of advanced decomposition. These findings indicate the usefulness of testing decomposed tissue for cocaine in all cases where its presence is suspected. This is contrary to what might be expected, since cocaine is generally labile and rapidly broken down by both enzymatic and nonenzymatic mechanisms.

Animals↗
PubMed1991

Valgus deformities of the feet and characteristics of gait in patients who have rheumatoid arthritis.

To investigate the cause of valgus deformity of the hindfoot in patients who have rheumatoid arthritis and to characterize the effects of the deformity on gait, two groups of patients were evaluated clinically, radiographically, and with gait analysis in the laboratory. Group 1 consisted of seven patients who had seropositive rheumatoid arthritis and normal alignment of the feet and Group 2, of ten patients who had rheumatoid arthritis and valgus deformity of the hindfoot. In Group 2, the disease was of longer duration and the feet were more painful than in Group 1. There was no evidence of muscular imbalance, equinus contracture, valgus deformity of the tibiotalar joint, or isolated deficiency of the tibialis posterior (such as weakness, tenosynovitis, or rupture of the tendon) that could have contributed to the development of the valgus deformity. In the patients who had valgus deformity, quantitated electromyography demonstrated that the intensity and duration of activity of the tibialis posterior was significantly increased, apparently in an effort to support the collapsing longitudinal arch of the foot. Gait studies revealed decreases in velocity, stride length, and single-limb-support time, as well as delayed heel-rise in both groups, but the decreases were more marked in the patients who had valgus deformity. The results of this study suggest that valgus deformity of the hindfoot in rheumatoid patients results from exaggerated pronation forces on the weakened and inflamed subtalar joint. These forces are caused by alterations in gait secondary to symmetrical muscular weakness and the effort of the patient to minimize pain in the feet. Radiographs also suggested an association between the valgus deformity of the feet and valgus deformity of the knees in patients who have rheumatoid arthritis.

Adult↗
PubMed1990

Methylthioadenosine serves as a single carbon source to the folate co-enzyme pool in rat bone marrow cells.

[ribose-U-14C]Methylthioadenosine (MTA) was prepared by incubating methionine with [14C-U]ATP in the presence of methionine adenosyltransferase and the resulting S-adenosylmethionine was heated to release MTA. Labelled [14C]MTA, when incubated with rat bone marrow cells, yielded [14C]formate which was used in the synthesis of adenine and guanine. Unlike 14C from sodium, formate, serine and glycine, there was no decline in 14C utilization from MTA with bone marrow cells from rats in which cobalamin had been inactivated by exposure to nitrous oxide. It was concluded that methionine via MTA is a significant contributor of single-carbon units at the formate level of oxidation and that this pathway is maintained in cobalamin 'deficiency'.

Adenine↗
PubMed1990

Cobalamin inactivation induces formyltetrahydrofolate synthetase.

Loss of cobalamin function produces profound changes in the metabolism of formate. There is impaired synthesis of formyltetrahydropteroylglutamate synthetase (CHO-H4PteGlu), accumulation of endogenous formate and impaired utilization of [14C]formate. There are contradictory reports on the effect of cobalamin inactivation on CHO-H4PteGlu synthetase. This study confirms a significant increase in synthetase activity following cobalamin inactivation.

Analysis of Variance↗
PubMed1990

Monoclonal antibodies to ROS 17/2.8 cells recognize antigens, some of which are restricted to osteoblasts and chondrocytes.

We have raised a panel of 15 monoclonal antibodies (MAbs) recognizing cell surface antigens of the rat osteoblast-like cell line ROS 17/2.8. The MAbs were selected on the basis of preferential binding to ROS 17/2.8 cells compared to ROS 25/1 cells. Immunohistochemical studies of antigen localization on cryostat sections of rat calvaria, long bone, and soft tissues demonstrated that five of these MAbs, UBIM 1, 2, 3, 12, and 17, recognize antigens that are restricted to normal rat osteoblasts and chondrocytes. The antigens appear to be localized to the cell surface of the osteoblast, with no apparent staining of bone matrix in either undecalcified or decalcified sections. In vitro, these MAbs recognize cell surface antigens present on two additional cell lines, ROS 24/1 and Rat 2 cells, and on the adherent cell population cultured from rat long bone marrow. Of these MAbs, three (UBIM 1, 2, and 3) recognize high-molecular-weight antigens of Mr 200,000-225,000. This study has also identified cell surface antigens of ROS 17/2.8 cells that are not expressed by osteoblasts in vivo. MAbs UBIM 9 and 21 bind to marrow cells in long bone sections, to the 7-day-old nonadherent cell population from cultured marrow, and to lymphoid tissue in sections of spleen. Another four MAbs (UBIM 10, 11, 14, and 22) bind to a variety of cells and tissues both in vitro and in vivo. Studies of the interactions of this panel of MAbs with osteogenic tissues and cell lines may have an important impact on the understanding of osteoblast physiology.

Animals↗
PubMed1990

Glucose tolerance in pregnancy: ethnic variation and influence of body habitus.

Little is known about ethnic differences in glucose tolerance during pregnancy. In this study we examined 3366 Hispanic, Chinese, black, and non-Hispanic white women in a universal screening program for gestational diabetes mellitus. After maternal age and body mass index were controlled, Chinese women had a significantly higher serum glucose level 1 hour after 50 gm of oral glucose (134.8 +/- 1.2, mean +/- SE) than any of the remaining three groups. Black women had a significantly lower value (113.3 +/- 1.3, mean +/- SE) than either Chinese or Hispanic women (124.4 +/- 0.9, mean +/- SE). Results for Hispanic women and non-Hispanic white women (121.4 +/- 1.6, mean +/- SE) were not different. The screening glucose levels of Chinese women were substantially higher than other ethnic groups even when women with gestational diabetes were removed from the analysis, indicating that the observed differences were not solely due to a higher frequency of gestational diabetes among the Chinese. The incidence of gestational diabetes was significantly greater for Chinese (7.3%) and Hispanic (4.2%) women than for black (1.7%) and non-Hispanic white (1.6%) women. Among women who had a 3-hour glucose tolerance test, the area under the glucose curve was significantly associated with maternal age and body mass index. The demonstrated heterogeneity of glucose tolerance between ethnic groups may be of importance in determining the threshold for diabetic fetopathy, and it is possible that ethnicity-specific standards will need to be developed.

Asian People↗
PubMed1990

5S rRNA sequences of representatives of the genera Chlorobium, Prosthecochloris, Thermomicrobium, Cytophaga, Flavobacterium, Flexibacter and Saprospira and a discussion of the evolution of eubacteria in general.

5S rRNA sequences were determined for the green sulphur bacteria Chlorobium limicola, Chlorobium phaeobacteroides and Prosthecochloris aestuarii, for Thermomicrobium roseum, which is a relative of the green non-sulphur bacteria, and for Cytophaga aquatilis, Cytophaga heparina, Cytophaga johnsonae, Flavobacterium breve, Flexibacter sp. and Saprospira grandis, organisms allotted to the phylum 'Bacteroides-Cytophaga-Flavobacterium' and relatives as determined by 16S rRNA analyses. By using a clustering algorithm a dendrogram was constructed from these sequences and from all other known eubacterial 5S RNA sequences. The dendrogram showed differences, as well as similarities, with respect to results obtained by 16S RNA analyses. The 5S RNA sequences of green sulphur bacteria were closely related to one another, and to a cluster containing 5S RNA sequences from Bacteroides and its relatives, including Cytophaga aquatilis. 5S RNA sequences of all other representatives of the 'Bacteroides-Cytophaga-Flavobacterium' phylum as distinguished by 16S RNA analysis failed to group with Bacteroides and related clusters. On the basis of 5S RNA sequences, Thermomicrobium roseum clustered with Chloroflexus aurantiacus, as was expected from 16S RNA analysis.

Base Sequence↗
PubMed1990

Formate metabolism in the cobalamin-inactivated rat.

Endogenous formate levels in blood and liver were assayed in rats both after inactivation of cobalamin (Cbl) by exposure to N2O as well as in air-breathing controls. The uptake of [14C]formate by tetrahydrofolate (H4folate) in bone marrow cells and liver homogenate and the incorporation of [14C]formate into purine, pyrimidine, methionine, serine and choline, was measured. There was a significant accumulation of endogenous formate following Cbl inactivation. There was impaired utilization of [14C]formate for single unit carbon (C1 unit) transfers mediated by folate in Cbl-inactivated tissues, other than for synthesis of adenine. The impairment was not accompanied by any accumulation of labelled methylH4folate indicating that methylfolate trapping played no part in impaired single carbon unit transfer. The effect of Cbl lack was a failure to form formylH4folate so that formate accumulated. The reason for this is not known.

Animals↗
PubMed1990

Instrumented gait analysis after selective dorsal rhizotomy.

In an attempt to assess quantitatively the effects of selective dorsal rhizotomy on ambulatory patients with cerebral palsy, instrumental gait analysis was used to document and compare changes following surgery. Stride characteristics, dynamic surface electromyography, foot-floor contact patterns and motion of the thigh, knee and ankle were analysed. 14 patients (seven independent ambulators, seven using assistive devices) aged between 4.6 and 23.5 years were tested before surgery and again six to 14 months later. After surgery, the seven independent walkers retained the same level of function and one of the assisted walkers had progressed to independent walking, but the other six still used the same device as before surgery. Selective dorsal rhizotomy reduces spasticity and improves gait dynamics, but does not change patterns of muscle activation during walking.

Adolescent↗