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Biomedical subjects

S L James

Publications and source records attributed to S L James.

At least 145 records · Page 8Linked to original sources
PubMed1981

Relationships between tibial rotary torque and knee flexion/extension after tendon transplant surgery.

The hamstring muscles play an important role in decelerating and checking tibial rotation before excessive stresses are applied to knee support structures. The purpose of this study was to determine the relationships between standard flexion/extension rehabilitative techniques and tibial rotary torque among subjects who had received pes anserinus transfers at least 1 year prior. Postsurgical and healthy contralateral limbs of 15 males were tested for maximum, isokinetic knee flexion/extension and internal/external tibial rotation. An adjustable chair and stabilizing boot were used to minimize extraneous hip, thigh and subtalar movements. Product-moment correlation coefficients were computed to determine the relationships between muscle forces generated during tibial rotation and knee flexion/extension. Relatively small relationships were found between rotation and flexion. Tibial rotation and flexion were more highly correlated in the nonsurgical than in the surgical limbs. The results also revealed that peak torque was generated within the first 5-10 degrees of motion for tibial rotation and within the first 20-30 degrees of motion for knee flexion and extension. The data indicate that measures of maximal knee flexor torque cannot be used to predict the rotational capabilities of the same muscle group and that separate measurement and rehabilitative techniques are necessary. Further analyses of postsurgical knees revealed force deficits among knee flexors and extensors when compared to nonsurgical counterparts. The findings suggest long-term sensitivity of the quadriceps to immobility.

Adolescent↗
PubMed1980

Mechanistic features of pepsin-catalyzed amino transfer reactions.

Peptic cleavage of N-trifluoroacetyl-L-tryptophan (CF3CO-Trp) at pH 2.45 to 5.4 in the presence of L-beta-phenyllactic acid (Pla) yields much PlaTrp. Formation of PlaTrp represents a typical peptic amino transfer reaction. In this instance PlaTrp undoubtedly derives from a reaction between the acceptor, Pla, and the carboxylate anion, CF3CO-TrpCOOO- (or a species obtained from it). This observation suggests that in general the anionic form of a substrate, such as AcPheTrpCOOO- in the case of AcPheTrp, may be the primary source of the amino acid residue transferred in amino transpeptidations. Other evidence supports the validity of the proposal. Furthermore it has the virtue of rationally explaining why AcPheTrpNH2-like substrates fail to participate in amino transpeptidations and why these reactions tend to increase in importance at high pH.

Amino Acid Sequence↗
PubMed1979

Purification of rodent eosinophils on discontinuous metrizamide gradients.

Methods are described for the purification of rat and mouse eosinophils. Peritoneal exudate cells obtained from Schistosoma mansoni- or Trichinella spiralis-infected mice were plated on plastic dishes, and the nonadherent cells were centrifuged over discontinuous hypertonic metrizamide gradients. Approximately 41% of those eosinophils present in the original preparations were recovered from the interfaces between 20% and 22% metrizamide at an average of 88% purity. Peritoneal cells obtained from either uninfected or S. mansoni-infected rats were placed directly onto metrizamide gradients. After centrifugation, essentially all eosinophils present in the original preparations were recovered at the interface between 18.5% and 22.5% metrizamide, with an average of 80% purity. These methods for eosinophil purification have proven to be reproducible and to yield cells which are morphologically preserved and functional, as demonstrated by their ability to respond to a chemotactic stimulus.

Animals↗
PubMed1979

A comparison of language samples elicited at home and in the clinic.

One of the most common methods of obtaining diagnostic information about a child's language production is to collect and analyze a spontaneous language sample. Usually, this sample is collected in a clinical setting by a speech-language pathologist. Because children's language production seems very sensitive to situational variables, there is some question about the representativeness of language samples obtained in clinical settings. This study compared language samples obtained in the home by the mothers with those obtained in the clinic by speech-language pathologists. Subjects were three- to five-year-old children who had been referred for speech and language diagnostics. Results were that the children's mean-length-of-utterance (MLU) scores were better for the home sample, although there was no difference between their Developmental Sentence Scores (DSS) for the home sample and the clinic sample. The home samples yielded higher MLU stage placements (Brown, 1973) and higher estimated language ages on the DSS (Lee, 1974) for most of the children. Clinical implications of the results are discussed.

Child, Preschool↗
PubMed1979

Cruciate ligament stents in reconstruction of the unstable knee. A preliminary report.

Cruciate ligament stents have been developed to severe as internal splints which provide excellent temporary stability while allowing full range of motion of the knee during postreconstruction rehabilitation. Forty-three patients with disabling chronic knee instability were treated at one center using similar reconstruction techniques with either the anterior or posterior cruciate stent. When both cruciate ligaments were absent, only the posterior was used. All stents are intended only as temporary internal splints and all patients were advised that the structures were expected to break eventually. Followup of 15 patients with anterior cruciate stents revealed only 50% satisfactory overall results. Overall results were satisfactory in 80% of 20 patients with posterior cruciate stents. Longer implant survival is needed, and this must be accomplished by building more flexibility into the stent core and by improving surgical technique with more precise instrumentation.

Adolescent↗
PubMed1979

Functional variability of the lower extremity during the support phase of running.

The purpose of the research was to determine the variability of selected parameters during the support phase of running between consecutive right footfalls, and the included left footfall, as well as to acquire additional descriptive data on lower extremity function. Eleven college aged male runners were filmed (200 fps) from the rear and side while running on a treadmill at 4.29--4.47 m/sec. The statistical analysis of the mean absolute differences for temporal events between the three footfalls resulted in no significant differences. An estimate of event variability was calculated to be the actual time +/- 0.0110 sec or the percentage +/- 4.98% at the 95% confidence interval. Comparisons between the absolute deviations of selected body part positions and/or orientations for the test conditions resulted in no statistically significant differences. Estimates of variability ranging from 1.78--4.08 deg were calculated. Even though no statistically significant differences were obtained, the magnitude of the variability obtained for the parameters evaluated would seem to indicate a need for calculating representative or average values if subtle differences in lower extremity function are to be detected.

Adult↗
PubMed1975

Cellular immunity in cancer: comparison of delayed hypersensitivity skin tests in three common cancers.

Cellular immunity was studied in three homogenous groups of patients with cancer to determine whether the pattern of depression of immune competence varied between solid tumours with different patterns of clinical behaviour. Delayed hypersensitivity skin responses were measured in patients with carcinoma of the breast, stomach, and colon and matched controls. Response to 2,4-dinitrochlorobenzene (DNCB) was used as an indication of primary responses and the Mantoux reaction as an index of recall responses. Responses were diminished in all three cancer groups, but there were significant differences between each type of cancer and even between different control groups. Cellular immunity was lost earliest and to the greatest extent in patients with colonic cancers and tended to be retained until a late stage in breast cancer, with gastric cancer occupying an intermediate position. Thus, while there was some degree of correlation between depressed immunity and prognosis our results gave no evidence that general host immune competence could explain the worse prognosis of gastric than colonic cancer. Paradoxical findings in patients with breast cancer suggested a great complexity in the host tumour interaction. Assessments of immune competence in cancer patients must be related to specific types of neoplasms with appropriate control groups if the results are to be meaningful.

Antibodies, Neoplasm↗