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Biomedical subjects

M Lee

Publications and source records attributed to M Lee.

At least 523 records · Page 29Linked to original sources
PubMed1996

Omeprazole prevents indomethacin-induced gastric ulcers in rabbits.

BACKGROUND: The role of gastric acid in the development of non-steroidal anti-inflammatory drug (NSAID)-induced gastric ulcers is unclear. The aim of this study was to determine the effect of the proton pump inhibitor omeprazole on the formation of indomethacin-induced gastric ulcers in a rabbit model. METHODS: Twenty-four rabbits were randomly divided into four groups and treated as follows: vehicle for indomethacin; vehicle for omeprazole; indomethacin (20 mg/kg b.d. subcutaneously for seven doses); and indomethacin plus omeprazole (both at 20 mg/kg b.d. subcutaneously for seven doses). On day 4 (after the seventh injection), rabbits were sacrificed, and gastric mucosal injury and prostaglandin formation were assessed. RESULTS: Subcutaneous administration of 20 mg/kg omeprazole b.d. caused a profound suppression of gastric acidity (i.e. pH above 5.0 continuously). This same dose of omeprazole significantly reduced gastric ulcer formation induced by indomethacin despite significant (> 80%) inhibition of gastric mucosal prostaglandin E2 (PGE2) formation. CONCLUSION: We conclude from these observations that gastric acid plays a critical role in the formation of indomethacin-induced gastric ulcers in rabbits.

Animals↗
PubMed1996

Towards a theory of lumbar mobilisation - the relationship between applied manual force and movements of the spine.

Optimal use of lumbar mobilisation requires a theoretical knowledge of the mechanical effects that occur. When a mobilisation force is applied the target vertebra will move with accompanying intervertebral displacements at many intervertebral joints. In addition, displacements and deformations of other tissues will contribute to the movement of the skin surface under the therapist's hands. The responses can be quantified in terms of the movements of the skin surface (described by the force-displacement relation), the absolute movement of the target vertebra, or the relative intervertebral movements. There are at least seven variables related to the manner of application of the mobilisation force that can be controlled by the therapist to alter the nature of the response. The patient's response is also determined by a number of variables related to the mechanical properties of the tissues of the spine, extra-spinal structures and the interaction between the patient and the treatment couch. Currently there is a moderate amount of information available about the effects of technique variations but there is very little data to directly link variations in the properties of specific anatomical structures with variations in either absolute or relative spinal movements or tissue loads.

Journal Article↗
PubMed1996

The capacity to be alone as a stress buffer.

The hypothesis that the ability to comfortably spend and use time alone is a buffer against effects of stress, comparable to social support, was tested. A 20-item instrument was developed to evaluate the capacity to be alone (Winnicott, 1958) and was then administered by telephone survey to 500 U.S. adults. Findings differed for two dimensions of the capacity to be alone. Reported comfort in being alone was found to be related to lower depression, fewer physical symptoms, and greater satisfaction with life. Reported ability to use time alone to deal with stress was not related to well-being. Neither dimension showed the expected interaction with stress, and individuals with high stress who reported high solitary coping exhibited greater vulnerability on one dimension of well-being, suggesting that this coping style may reflect maladjustment.

Adaptation, Psychological↗
PubMed1996

A murine homologue of the human DAZ gene is autosomal and expressed only in male and female gonads.

We have isolated a homologue of the human Y linked DAZ (deleted in azoospermia) gene from mouse. This gene, Dazla (Daz like, autosomal), is autosomal, located on chromosome 17 and apparently single copy. The predicted protein is highly homologous to that encoded by the DAZ gene in the N-terminal regions of the two proteins and this homology is not confined to the RNA binding domain. Analysis of its expression pattern by reverse transcription PCR shows that the transcript is only detectable in male and female gonads and that testes lacking germ cells do not contain detectable amounts of transcript. We have been unable to detect a Y-linked DAZ homologue in mouse and our results point to the possibility of a role for autosomal RNA binding proteins in mammalian gametogenesis.

Amino Acid Sequence↗
PubMed1996

Ott, a mouse X-linked multigene family expressed specifically during meiosis.

The tissue expression patterns of 10 mouse testis cDNAs were analysed by RT-PCR to search for new mammalian meiotic genes. The homologue of the rat synaptonemal complex protein gene SCP1 is expressed in embryonic ovary, adult brain and testis. One novel gene is stringently testis specific and another is expressed exclusively in testis and embryonic ovary. The latter clone is not expressed in the testes of adult sex-reversed mice which lack germ cells, and therefore represents a meiosis-specific gene. It is part of a mouse multigene family, members of which are clustered and map genetically and physically to a single region of the X chromosome. We have named this family Ott (ovary testis transcribed). Steady-state levels of a 2.3 kb polyadenylated Ott mRNA are high throughout meiotic prophase in the testis when the X chromosome is generally transcriptionally inactive. A second transcript of 1 kb is also detectable from 4 weeks of age onwards. The two mRNAs have different 3' ends and contain different protein coding information. At least seven Ott genes are transcribed specifically during meiosis and are predicted to encode "pioneer' proteins with an unusual structure, containing tandem arrays of a degenerate eight amino acid repeat. This work could lead to the identification of a human Ott homologue, which is likely to be X-linked and would provide a candidate locus for some cases of male infertility.

Amino Acid Sequence↗
PubMed1996

Evaluation of a new device for measuring responses to posteroanterior forces in a patient population, Part 1: Reliability testing.

BACKGROUND AND PURPOSE: This study determined the test-retest reliability of measurements of responses to posteroanterior (PA) forces made using a recently developed instrument. SUBJECT: Twenty-two subjects with nonspecific low back pain participated. METHODS: The length of the low- stiffness or "toe" region and the slope of the linear portion of the force-displacement curve were measured on two occasions. Reliability of repeated measurements was evaluated by intraclass correlation coefficients and percentage-of-agreement scores. The presence of a systematic change in the response to PA forces was evaluated by a paired-samples t test. RESULTS: High reliability coefficients were obtained for both indices of the response to PA forces. The t test revealed no systematic change with repeated testing. CONCLUSION AND DISCUSSION: The new device provides highly reliable measurement of the lumbar PA force-displacement relationship and may prove useful in evaluating theories that have suggested a relationship between spinal symptoms and abnormal PA stiffness.

Adult↗
PubMed1996

Cyanoacrylate tissue adhesive in blepharoplasty.

This article reports the results of an animal study designed to evaluate the usefulness of butyl 2-cyanoacrylate (Histoacryl) in blepharoplasty skin closure. Bilateral upper and lower lid blepharoplasty skin incisions were made on seven pigs. We compared the wounds closed with 6.0 nylon to those closed with Histoacryl at 1, 2, 4, and 9 weeks postoperatively. The tensile strength of the "glued" incisions was significantly greater than that of the sutured incisions only at the 9-week postoperative interval (p < 0.05). There was no significant difference in bond strength, however, between the two methods at 1, 2 and 4 weeks postoperatively. Histopathologic analyses of sutured and glued wounds were compared at the same designated postoperative periods. No deleterious effects were found in the overall healing of the cutaneous wounds closed with Histoacryl.

Analysis of Variance↗
PubMed1996

Intramedullary spinal cord tumors in neurofibromatosis.

Neurofibromatosis (NF) describes the most commonly inherited disorders affecting the nervous system. These autosomal dominant, neurocutaneous syndromes are associated with multiple tumors of the nervous system, including neurofibromas, schwannomas, meningiomas, and intracranial gliomas. Spinal cord involvement in NF is typically from extramedullary growth of spinal nerve root tumors. Intramedullary spinal cord tumors in NF have been reported as scattered, single cases in literature. However, this association has not been clearly defined as have other nervous system neoplasms that are typically linked with NF. We present a series of nine patients with NF with intramedullary spinal cord tumors who were managed at our institution from 1984 to 1994. The patients' ages ranged from 4 to 31 years. There were seven male patients and two female patients. Three patients had NF-1 (von Recklinghausen's), five patients had NF-2, and one patient had NF, type uncertain. There were three cervicomedullary tumors, two cervical tumors, three cervicothoracic tumors, and one thoracic tumor. A histological examination revealed five ependymomas, three astrocytomas, and one intramedullary schwannoma. Two patients with malignant intramedullary spinal ocrd tumors have died with progressive disease. One other patient has required a subsequent operation for recurrent tumor. The other six patients are doing well, and their prognosis is expected to be related to their systemic disease. We conclude that there is a clinical entity of intramedullary spinal cord tumors associated with NF.

Adolescent↗
PubMed1996

Functional anatomic relationship between brain-stem tumors and cranial motor nuclei.

OBJECTIVE: To identify patterns of cranial motor nuclei (CMN) displacement in cases of intramedullary brain stem tumor, using neurophysiological mapping of motor nuclei on the floor of the fourth ventricle. METHODS: Relationships between tumors and CMN were reviewed in 18 patients with brain stem tumors (seven pontine, nine medullary, and two pontomedullary tumors) and 2 with cervicomedullary junction spinal cord tumors. CMN VII, IX/X, and XII were mapped by applying electrical stimuli over the surgically exposed fourth ventricular floor through a handheld probe and recording electrical activity in the appropriate cranial muscles. RESULTS: Tumors distorted the anatomic location of CMN in repetitive patterns according to tumor site. Three patterns were identified as follows: Type 1, CMN located around the tumor on the floor of fourth ventricle; Type 2, one or more CMN located ventrally to the tumor; Type 3, CMN in original anatomic position. Six of seven patients with pontine tumors showed the Type 1 pattern. Seven of nine patients with medullary tumors showed Type 2, and the other two showed Type 1. Both patients with pontomedullary tumors showed Type 2. One patient with a cervicomedullary junction spinal cord tumor showed Type 1 and the other Type 3, depending on the tumor extension into the fourth ventricle. CONCLUSION: Pontine tumors push the CMN to around the tumor edge, suggesting that precise localization of CMN before tumor resection is necessary to avoid their damage. Medullary tumors grow more exophytically and compress the CMN ventrally. Understanding patterns of CMN displacement can help surgeons establish the surgical plan, minimize risks, and enable safer surgery of brain stem tumors.

Adolescent↗
PubMed1996

Eosinophilic gastroenteritis.

Eosinophilic gastroenteritis is a rare condition of unknown etiology characterized by peripheral eosinophilia, eosinophilic infiltration of the gastrointestinal tract, and gastrointestinal symptomatology. Eosinophilic gastroenteritis is generally classified according to the layer of gastrointestinal tract involved. Mucosal involvement may result in abdominal pain, nausea, vomiting, diarrhea, weight loss, anemia, protein-losing enteropathy, and intestinal perforation. Patients with muscular layer disease generally have obstructive symptoms. Subserosal eosinophilic infiltration may result in development of eosinophilic ascites. Patients with mild and sporadic symptoms can be managed with reassurance and expectant observation. Patients with disabling symptoms can be effectively treated with corticosteroids after other systemic disorders associated with peripheral eosinophilia have been excluded. Occasionally, sodium cromolyn, ketotifen, and/or elimination diets have been shown to be effective in the management of patients who have a significant history of allergic disorder. Surgical intervention may be required in patients with obstructive complications or refractory disease.

Abdominal Pain↗
PubMed1996

Superior mesenteric artery syndrome in an intravenous drug abuser after rapid weight loss.

Superior mesenteric artery (SMA) syndrome is a form of small-bowel obstruction due to vascular compression of the duodenum. We describe a case of SMA syndrome in an intravenous drug abuser who had rapid weight loss during a 2-week drug binge. Radiographic studies are necessary to confirm the diagnosis, and our case illustrates the value of computed tomography in diagnosing this relatively rare but serious disorder. The management of this syndrome requires reversing or removing the precipitating factors as well as correcting any secondary complications. Increased awareness of this condition may result in improved recognition and timely management of this rare cause of high intestinal obstruction, thus reducing its potential morbidity and complications.

Adult↗
PubMed1996

Cisapride as a successful treatment for acute intestinal pseudo-obstruction.

Cisapride has been used in the treatment of chronic intestinal pseudo-obstruction with some success; however, the use of cisapride in the treatment of acute pseudo-obstruction has not been adequately studied. We describe a case of acute intestinal pseudo-obstruction successfully treated with cisapride. To our knowledge, this is the second such case reported in the English language literature. Our patient's acute intestinal pseudo-obstruction was probably precipitated by pneumonia and sepsis, and the prompt resolution of his intestinal pseudo-obstruction after initiation of cisapride therapy (despite progressive deterioration of his overall clinical status) implicates cisapride as the cause of the improved intestinal function. Therefore, we suggest that a trial of cisapride be considered for patients with acute intestinal pseudo-obstruction when other therapeutic maneuvers have failed.

Acute Disease↗
PubMed1996

Employee attitudes toward work-site alcohol testing.

Few studies have been published on how employees feel about work-site alcohol testing. By mail, we surveyed employees (n = 6370) at 16 corporate work sites stratified by type of work force, industrial setting, and managerial tolerance toward drinking. We queried respondents about their drinking on the job and support for work-site alcohol testing under three conditions: pre-employment testing, testing after an accident, and random testing. Sixty-five percent of respondents supported pre-employment testing, 81% supported testing after an accident, and 49% supported random testing. Support was relatively consistent across hierarchy (managers, supervisors, and workers) but different by age, education, occupation, type of work force, and perceived exposure to occupational hazards. Support for work-site alcohol testing was highest among blue-collar workers whose jobs involved manufacturing or exposure to work-site hazards.

Accidents, Occupational↗
PubMed1996

Aspirin suppresses 1,2-dimethylhydrazine-induced alteration of proliferative parameters in rat colonic crypts.

Human epidemiological reports and rodent experimental research data indicate a possible chemopreventive effect of regular aspirin use for decreasing risk of colon and rectum cancer incidence and mortality. We have previously demonstrated that aspirin can significantly suppress proliferative parameters in normal rat colonic epithelium when examined 24 h following an acute or chronic course of aspirin administration. To investigate whether aspirin would effectively suppress known carcinogen-induced changes in colonic epithelium, rats were given single s.c. injections of either aspirin (50 mg/kg bw) or saline on days 1-3 and either 1,2-dimethylhydrazine (DMH; 12 mg base/kg bw) or DMH vehicle on day 4 of each week for eight consecutive weeks. Rats were sacrificed 4 days after the last aspirin dose and 3 days after the last DMH or DMH vehicle dose. Using the proliferative biomarkers of proliferating cell nuclear antigen positive cells per midaxial crypt section (SCC), crypt proliferative zone height (PZ), crypt differentiated zone height (DZ), and total crypt height (CH), it was found that aspirin does suppress DMH-induced increases in SCC, PZ and CH. The findings demonstrate that aspirin has a long term (i.e. several days) protective effect against early carcinogen-induced proliferative changes in rat colonic crypts which may help account for aspirin's chemopreventive action against colon cancer.

1,2-Dimethylhydrazine↗
PubMed1996

Total artificial heart using neural and fuzzy controller.

The aortic pressure (AoP) and pulmonary artery pressure (PAP) are important factors for the long-term survival of the patient receiving an implant of a total artificial heart (TAH). A new afterload regulation method using neural controllers has been developed for a moving actuator type TAH. Without any transducer, the proposed neural controller, based on the predetermined peak level of the motor current, regulates AoP by adjusting the actuator velocity. At the same time, a fuzzy controller based on expert knowledge prevents the PAP from being abnormally high. The proposed controller not only regulates the pump output on the maintenance of the normal AoP and PAP, but it also successfully controls the suction in the right heart. In vitro tests show that the proposed neural and fuzzy controllers effectively regulate AoP and PAP as well as prevent atrial suction.

Blood Pressure↗
PubMed1996

Task dynamic and articulatory recovery of lip and velar approximations under model mismatch conditions.

An algorithm for recovering task dynamics and speech articulator movements from speech acoustics was tested under various model mismatch conditions. There was evidence of articulatory compensation to recover tract-variable (constriction) trajectories in speech produced with a lip approximation under sufficiently constrained conditions. However, in more extensive studies of lip and velar approximations, the recovered tract-variable trajectories were also different from those of the data-producing utterance. This phenomenon can occur because the matching criterion in the analysis-by-synthesis procedure is an acoustic criterion and the correspondence between the tract-variable trajectories and the acoustic output is not exact. While there may be some tract-variable compensation to attain a good acoustic match, there is evidence of a correspondence between how well the tract-variable trajectories match and how well the formant frequencies match in particular instances.

Humans↗