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Biomedical subjects

M B Harris

Publications and source records attributed to M B Harris.

At least 55 records · Page 3Linked to original sources
PubMed1996

Traumatic hip dislocation during childhood. A case report and review of the literature.

Traumatic hip dislocations rarely occur during childhood. Males sustain pediatric hip dislocations four times more often than do females. Posterior hip dislocations comprise 87% of all pediatric hip dislocations. A soft, pliable acetabulum and ligamentous laxity predispose the immature hip joint to a dislocation secondary to minimal trauma. Potential associated injuries include fractures and neurovascular injury, whereas avascular necrosis (AVN) and degenerative joint disease are potential sequelae. Optimal treatment should be prompt reduction of the hip in order to minimize the risk of AVN of the femoral head.

Accidental Falls↗
PubMed1995

Treatment of osteosarcoma with ifosfamide: comparison of response in pediatric patients with recurrent disease versus patients previously untreated: a Pediatric Oncology Group study.

This study was designed to test if the activity of a phase II agent, ifosfamide, would have been underestimated if it was tested exclusively in a population of children and young adults with recurrent osteosarcoma. The response rate to ifosfamide was compared in patients younger than 30 years of age with previously untreated osteosarcoma with metastases at diagnosis and/or unresectable primary tumors (stratum 1) with that of patients with recurrent osteosarcoma following adjuvant chemotherapy who were not previously exposed to ifosfamide (stratum 2). Evaluation of response was conducted 3 weeks after two courses of ifosfamide (2400 mg/m2 x 5 days) were administered 3 weeks apart. Nine of 33 (27%) evaluable patients in stratum 1 responded (1 complete and 8 partial responses) to ifosfamide. Among 30 evaluable patients in stratum 2, only 3 (10%) responded (1 complete and 2 partial responses; P = .04) Both groups of patients received equal doses of ifosfamide and experienced comparable toxicities. Results from this study suggest that the activity of new agents will be underestimated if tested in a population of heavily pretreated patients with recurrent disease. When possible, new chemotherapeutic agents should be tested in patients with a poor prognosis who have not been exposed to chemotherapy.

Adolescent↗
PubMed1995

Globus pharyngis: development of a symptom assessment scale.

One hundred and five consecutive patients attending an ENT out-patients' clinic with a diagnosis of globus pharyngis completed a 10-item questionnaire concerning common throat symptoms. Principal components analysis of the questionnaire revealed a general throat pathology factor, and three orthogonal rotated factors which were related to dysphagia, globus sensation, and pain/swelling in the throat. Of 10 throat symptoms, the globus patients most commonly complained of: "Feeling of something stuck in the throat," "Discomfort/irritation in the throat," and "Want to swallow all the time." These were the symptoms which had highest loadings on the 'globus' factor. The clear factor structure and the satisfactory internal consistency of the Glasgow-Edinburgh Throat Scale (GETS) suggest that it offers a clinically useful instrument for assessing and monitoring the severity of some common throat ailments. The degree of distress caused by throat symptoms was predicted independently by the intensity of the globus sensation and by anxiety level.

Adult↗
PubMed1995

Ifosfamide/carboplatin/etoposide (ICE) for recurrent malignant solid tumors of childhood: a Pediatric Oncology Group Phase I/II study.

PURPOSE: The combination of ifosfamide (I) and etoposide (E) was useful in salvaging patients with recurrent/resistant malignant solid tumors of childhood. Carboplatin (C), active against a number of pediatric cancers, was added to I and E to form a three-drug combination called ICE to improve the response rate. PATIENTS AND METHODS: ICE, consisting of I 1.5 g/m2 plus E 100 mg/m2 i.v.q.d. x 3 plus C i.v. on day 3 only, was given in 21-28-day intervals. C was started at 300 mg/m2, and the dose was escalated in 25% increments, with three evaluable patients treated at each level. RESULTS: Ninety-two patients were enrolled in this phase I/II study between July 1990 and April 1993. A total of 331 courses of ICE was administered. Median courses of ICE received were three (range, 1-16). The maximum tolerated dose (MTD) for C when used in combination was found to be 635 mg/m2. The response rate for ICE at the MTD for C was complete response (CR) 26% and CR + partial response (PR) 53%. The response was even better in those who received C at the MTD: 32% achieving a CR and 63% a CR + PR. Pancytopenia was the dose-limiting toxicity. Thirteen episodes of bacterial infection were reported, none fatal. Only one patient developed a Fanconi-like syndrome. CONCLUSION: The MTD of C when used with I and E was found to be 635 mg/m2. The overall CR + PR rate for all patients treated at all C dose levels was 53%. Best responses were seen in non-Hodgkin's lymphoma, neuroblastoma, soft tissue sarcomas, and Wilms' tumor.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Parasympathetic influence on heart rate in euthermic and hibernating ground squirrels.

The relative role of the parasympathetic nervous system during deep hibernation is enigmatic. Conflicting hypotheses exist, and both sides draw support from investigations of vagal influence on the heart. Recent studies have shown cardiac chronotropic and inotropic effects of parasympathetic stimulation and inhibition in isolated hearts and anesthetized animals at hibernating body temperatures. No studies, however, have demonstrated such occurrences in undisturbed deeply hibernating animals. The present study documents respiratory-related alterations in heart rate during euthermia and hibernation at ambient temperatures of 15, 10 and 5 degrees C mediated by parasympathetic influence. During quiet wakefulness, euthermic squirrels breathed continuously and exhibited a 29% acceleration in heart rate during inspiration. During deep undisturbed hibernation, at 15, 10 and 5 degrees C ambient temperature, animals exhibited an episodic breathing pattern and body temperatures were slightly above ambient temperature. At each temperature, heart rate during the respiratory episode was greater than that during the apnea. The magnitude of this ventilatory tachycardia decreased with ambient temperature, being 108% at 15 degrees C, 32% at 10 degrees C and 11.5% at 5 degrees C. Animals exposed to 3% CO2 at 5 degrees C, which significantly increased ventilation, still exhibited an 11.7% increase in heart rate during breathing. Thus, the magnitude of the ventilation tachycardia was independent of the level of ventilation, at least over the range studied. Inhibition of vagus nerve conduction at 5 degrees C was achieved using localized nerve block. This led to an increase in apneic heart rate and abolished the ventilatory tachycardia.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

The effects of the interosseous membrane and partial fibulectomy on loading of the tibia: a biomechanical study.

The biomechanical basis for the treatment of delayed union of tibial fractures by partial fibulectomy has yet to be fully evaluated. To gain further insight into this problem, nine intact cadaveric lower extremities were instrumented with strain gauges on the surfaces of the tibia and fibula. The limbs were then subjected to axial loading with the ankle and subtalar joints placed in multiple positions. The specimens were loaded either through the distal femur or by direct loading of the tibial plateau. All specimens were first tested intact then after sectioning of the interosseous membrane and finally after partial fibulectomy. It was shown that during loading of the leg, the primary effects of the interosseous membrane were to stabilize the fibula and constrain its posterolateral bending. The fibular strains were not reduced to zero following sectioning of the interosseous membrane. Tibial strains measured on the anteromedial and anterolateral surfaces were consistently in relative tension, indicating a posterior bending force (anterior bowing) of the tibia. After partial fibulectomy, strains on these surfaces became relatively more compressive. With the ankle and subtalar joints in neutral position (0 degree flexion, 0 degree inversion/eversion) the strains on the anterior surface averaged approximately 10% more compressive relative to the intact condition. Tibial strains were observed to vary with the position of the ankle and subtalar joints. The fact that the anteromedial and anterolateral tibia surfaces were always in tension may explain why partial fibulectomy has not proved to be a uniformly successful treatment method for delayed union of the tibia. Furthermore, it points to the important role of "fracture personality" in the selection of treatment.

Aged↗
PubMed1994

Changing hysterectomy patterns after introduction of laparoscopically assisted vaginal hysterectomy.

OBJECTIVE: The objective of this study was to determine whether introduction of laparoscopically assisted vaginal hysterectomy decreases the percentage of women requiring laparotomy for hysterectomy. STUDY DESIGN: A retrospective review of women undergoing hysterectomies from 1990 through 1992 was performed. Type of hysterectomy and total hospital charges were determined. Indication for surgery and complications in the laparoscopically assisted vaginal hysterectomy group were also examined. RESULTS: During the study interval 670 hysterectomies were performed. In 1990 and 1991 abdominal hysterectomies comprised 51.5% and 45.5% of all hysterectomies, respectively. After introduction of laparoscopically assisted vaginal hysterectomy in 1992 the percentage of abdominal hysterectomies declined to 35.6%, whereas the percentage of unassisted vaginal hysterectomies remained stable. The complication rate for patients with laparoscopically assisted vaginal hysterectomy was 16%. Average cost was $11,931 compared with $7031 for abdominal hysterectomy and $5343 for vaginal hysterectomy. CONCLUSION: Laparoscopically assisted vaginal hysterectomy can decrease the number of patients requiring a laparotomy for hysterectomy but at a much greater cost.

Adult↗
PubMed1994

Growing old gracefully: age concealment and gender.

In order to investigate some of the relationships between age concealment and gender, 269 adults completed on anonymous questionnaire dealing with signs of aging and the use of techniques to conceal them. Although most of the signs of aging were considered unattractive for both males and females, aging women were seen as particularly unappealing. More women than men were expected to use age concealment techniques and female subjects were indeed more likely to use them. Both men and women who concealed their age were likely to be judged harshly by others, although individuals indicated a willingness to use age concealment techniques themselves. The results are consistent with the hypothesis that there are two different double standards of aging, one indicating that aging is judged differently depending on the gender of the person doing the judging and the target, and one indicating that people may judge the use of age concealment techniques more harshly in others than in themselves.

Adolescent↗
PubMed1994

Iliac crest reconstruction after tricortical graft harvesting.

Twenty-eight patients underwent anterior iliac crest reconstruction after the harvesting of autogenous tricortical graft. The anterior iliac crest was reconstructed using the resected rib from the thoracoabdominal approach. The authors evaluated graft site pain and residual deformity, radiographic evidence of rib incorporation, and the incidence of lateral femoral cutaneous nerve injury. There were no reports of graft site pain greater than "acceptable" levels, requiring nonnarcotic analgesics on an intermittent basis and not interfering with activities of daily living. Four lateral femoral cutaneous nerve neuropraxias were recorded, none of clinical significance. The authors advocate the use of autogenous tricortical anterior iliac crest bone graft when performing reconstructive spinal surgery, followed by reconstruction of the iliac crest with the resected rib from the surgical approach.

Adolescent↗
PubMed1994

Evaluation of methods of internal fixation of transverse patella fractures: a biomechanical study.

Biomechanical testing was performed to evaluate five techniques of internal fixation of transverse patella fractures. Using cadaveric lower extremities, transverse osteotomies of the patella were performed, and the simulated fractures were fixed with the following techniques: the modified tension band, anterior tension band with a supplemental cerclage wire (the Pyrford technique), tension band with cancellous bone screws, Pyrford technique with cancellous screws, and cancellous screws alone. The fixation techniques were evaluated by measuring the separation of the fracture fragments during loading to produce a physiologic range of motion (90 degrees flexion to full extension). All techniques functioned adequately, with no fracture gap exceeding 1 mm. The tension band with screws technique performed significantly better than did the modified tension band, with an average fracture gap approximately half that of the traditional modified tension band technique. Mechanically, the addition of the screws to the tension band techniques reduces fracture separation by providing compression throughout the range of motion and by resisting the tensile loading during terminal extension.

Aged↗
PubMed1994

Comparison of two schedules of intermediate-dose methotrexate and cytarabine consolidation therapy for childhood B-precursor cell acute lymphoblastic leukemia: a Pediatric Oncology Group study.

PURPOSE: To compare efficacy and toxicity of two schedules of intermediate-dose methotrexate (IDM) and cytarabine (Ara-C) in remission consolidation of childhood acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS: In 1986, the Pediatric Oncology Group (POG) began a randomized trial to test two schedules of consolidation chemotherapy in children with newly diagnosed B-precursor cell ALL. MTX and Ara-C were given as overlapping 24-hour infusions. The dose and sequence of MTX and Ara-C administration were based on a preclinical model that had demonstrated synergism between these two agents. Two hundred fifteen patients in complete remission were randomized to front-loading consolidation therapy in which six MTX/Ara-C infusions were administered at 3-week intervals from the 7th through the 19th week of therapy. Two hundred thirteen patients in complete remission were randomized to receive standard consolidation therapy in which the six MTX/Ara-C infusions were given every 12 weeks from the 7th through the 67th week of therapy. RESULTS: Both regimens produced similar rates of adverse side effects, except for a higher incidence of CNS toxicity in individuals randomized to the front-loading arm (32 of 215 v 12 of 213 patients, P = .002). Leukoencephalopathy occurred in three patients on the front-loading regimen and was permanent in one. By Kaplan-Meier analysis, the probability of continuing in complete remission for 5 years was 79% (SE = 5%) and 85% (SE = 5%) for good-risk patients, and 66% (SE = 6%) and 61% (SE = 7%) for poor-risk patients randomized to front-loading and standard regimens, respectively. CONCLUSION: Although differences in complete remission durations were not statistically significant by log-rank analysis (P = .62 for good-risk patients, .89 for poor-risk patients, and .99 overall), the results are comparable to those in previous studies using more toxic agents as components of remission consolidation therapy.

Adolescent↗
PubMed1993

Cervical spondylolysis. Report of two cases.

Two cases of cervical spondylolysis are presented. Both cases were discovered during radiographic examination after incidental trauma. The first patient experienced transient quadriplegia that spontaneously resolved and the other experienced only neck pain. Further radiographic evaluation of the first patient revealed significant spinal cord compromise, ultimately requiring decompression and fusion. The second patient's cervical spine proved stable to dynamic studies and was without cord compromise.

Adult↗
PubMed1993

On friendship.

Explore the source record for details and available documents.

Empathy↗
PubMed1993

Anatomical and roentgenographic features of atlantooccipital instability.

An anatomical study using six fresh, human cadaveric cervical spine specimens was performed. After the dissection of all soft tissue, flexion-extension radiographs were obtained to verify initial stability. A sagittal plane bone cut was then made, centered on the odontoid and sparing the alar ligaments, the tectorial membrane, and the atlantooccipital (AO) ligaments. Repeat flexion-extension radiographs and photographs were taken to document maintenance of stability of these hemisections. The occipital-atlantoaxial ligaments were then individually and sequentially incised, maintaining all other structures each time. After the sectioning of each ligament, flexion-extension radiographs and photographs were obtained to identify subsequent motion patterns. Both gross anatomical and roentgenographic examinations demonstrated the important stabilizing role of the tectorial membrane in flexion. Additionally, contact between the posterior arch of C1 and the occiput limited hyperextension as a secondary restraint once the tectorial membrane was sectioned. Furthermore, the AO ligaments proved to play an insignificant role in the preservation of AO stability through a flexion-extension arc of motion. Under normal circumstances, the AO articulation is not excessively stressed. However, acute AO injury, as well as the insidious failure of these ligaments, has been documented in several cases involving various pathologies. This study demonstrates a mechanism of instability and highlights the essential role of the tectorial membrane in maintaining upper cervical spine stability.

Atlanto-Occipital Joint↗
PubMed1992

Trisomy of leukemic cell chromosomes 4 and 10 identifies children with B-progenitor cell acute lymphoblastic leukemia with a very low risk of treatment failure: a Pediatric Oncology Group study.

To account for the superior prognosis of hyperdiploid, B-progenitor acute lymphoblastic leukemia (ALL), we investigated the influence of trisomy in 1021 children greater than or equal to 1 year old by recursive partitioning analysis. The patients were treated according to a stratified, randomized study testing antimetabolite-based therapies. Trisomies of several individual chromosomes were associated with a better prognosis in a univariate statistical analysis. Of greater importance, trisomy of both chromosomes 4 and 10 identified a subgroup of patients (n = 180) with an extremely favorable 4-year event-free survival (EFS). Combined trisomy of chromosomes 4 and 10 retained its prognostic significance after stratification of patients by DNA index, age, and leukocyte count. Among patients with a DNA index greater than 1.16, patients with trisomies of both chromosomes 4 and 10 had a 4-year EFS of 96.6% (n = 161, SE = 3.8%), whereas patients with neither or only one of these trisomies had a 4-year EFS of 70.4% (n = 73, SE = 11.5%). All 19 patients with a DNA index less than or equal to 1.16 but with trisomies of chromosomes 4 and 10 remain in remission, suggesting that favorable chromosome trisomy dominates in a situation in which the cellular DNA content of less than or equal to 1.16 predicts a less favorable outcome. We conclude that combined trisomy of chromosomes 4 and 10 independently predicts EFS among children with B-progenitor ALL. Patients within the B-progenitor group who have this feature (about 20% of those with clonal abnormalities) are likely to be cured with antimetabolite-based chemotherapy--an approach that should produce few significant late effects.

Adolescent↗
PubMed1992

Unique histological changes in lung metastases of osteosarcoma patients following therapy with liposomal muramyl tripeptide (CGP 19835A lipid).

We have recently begun a phase II trial in patients with osteosarcoma who developed pulmonary metastases during adjuvant chemotherapy or who presented with pulmonary metastases that persisted despite chemotherapy. Eligible patients were rendered free of visible disease by surgery. Liposome-encapsulated muramyl tripeptide phosphatidylethanolamine (MTP-PE, CGP 19835A lipid) (2 mg/m2) was infused twice weekly for 3 months. In five patients, a single tumor nodule recurred within 6 weeks after completion of therapy. These lesions were resected and submitted for pathological examination. Tissue specimens obtained after therapy were compared to those obtained before therapy. All the patients showed a histological change in the characteristics of the pulmonary tumors. In three patients, peripheral fibrosis surrounded the tumor and inflammatory cell infiltration and neovascularization were present. This is in contrast to central necrosis, with viable peripheral tumor cells and no inflammatory response observed in lesions resected following chemotherapy. In a fourth case, evidence of early fibrotic changes was found. This and the fifth case showed a change in malignant characteristics, from high grade before liposomal therapy to low grade after therapy. The present study provides evidence for a biological effect of liposomal MTP-PE.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1992

Effects of real gender and labeled gender on adults' perceptions of infants.

Three experiments were conducted to discover factors mediating adults' perceptions of male and female infants. In the first experiment, college students were shown 30-s videotapes of four male and four female babies, each of whom was randomly labeled with a male or a female name. Infants labeled as male were perceived as significantly more masculine and stronger than those labeled as female. Discriminant analyses revealed that both rated masculinity and the combination of ratings on male stereotyped traits differentiated infants labeled as male or female. Analyses of real gender revealed that boys were rated as less sensitive and stronger than girls. Discriminant analyses suggested that the combination of less sensitive, more of a problem, more mature, and more playful best differentiated real males from real females. In Experiment 2, the findings of Experiment 1 were confirmed with a sample of mothers of young infants. In Experiment 3 college students' judgments of the sex of the eight babies were correctly predicted from the sensitivity ratings of these babies in Experiment 1. It appears that there is a complex of cues from which adults make judgments of infants' gender and inferences about their characteristics: Boys may appear stronger, more playful, and more of a problem, and girls seem to look more sensitive. Implications for further studies of gender labeling and for sex typing are discussed.

Adult↗