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Biomedical subjects

L Martin

Publications and source records attributed to L Martin.

At least 325 records · Page 18Linked to original sources
PubMed1995

Verruciform xanthoma of the penis with acantholytic cells.

Verucciform xanthoma is an unusual lesion characterized by verrucous epithelial proliferation accompanied by a prominent replacement of the dermal papillae with foamy histiocytes. We describe a case of verruciform xanthoma on the glans penis. The most striking histopathological finding was the presence of numerous acantholytic cells in the upper layers of the epithelium. We discuss the differential diagnosis with other acantholytic disorders of the genital area and conclude that our findings can be interpreted as an additional example of incidental acantholysis.

Acantholysis↗
PubMed1995

Brain noradrenergic systems modulate the ceco-colonic myoelectric activity in rats.

The role of the brain noradrenergic systems in the control of the ceco-colonic myoelectric activity was investigated in rats following lesions with intracerebroventricular (icv) or intracisternal (ic) injection of 6-hydroxydopamine (6-OHDA). Controls received the vehicle alone. The ceco-colonic myoelectric activity was recorded 3 weeks later in conscious rats chronically fitted with electrodes. After icv injection of 6-OHDA, lesions of rostral and caudal (spinal) noradrenergic systems were observed whereas only spinal noradrenergic systems were lesioned after ic injection. This differential pattern of lesions was followed by a differential pattern of ceco-colonic myoelectric activity. In fasted animals, a significant increase of the long spike burst (LSB) frequency (nb min-1) was observed after icv injection of 6-OHDA whereas no modification was observed after ic injection of the neurotoxic. After a 6-g pelleted rat diet, a significant increase of the LSB frequency was also observed in the icv lesioned group when compared to controls. No modification of the ceco-colonic noradrenergic innervation was observed, thus confirming the central selectivity of these lesions. Lesions of central noradrenergic systems modify the LSB frequency in rats; the rostral noradrenergic systems seem to play the major role.

Animals↗
PubMed1995

Chronic cough associated with subacute bacterial endocarditis.

Although the literature on subacute bacterial endocarditis from both the preantibiotic and antibiotic eras mentions cough as a symptom, neither bacteremia nor endocarditis is listed in reviews on chronic cough. Herein we describe a 74-year-old man who underwent an extensive workup as an outpatient because of chronic cough of 7 months' duration. Chest roentgenography, chest and sinus computed tomography, fiberoptic bronchoscopy, gallium scan, transthoracic echocardiography, and other studies revealed no apparent cause for his nonproductive cough. Because of a persistently increased erythrocyte sedimentation rate and associated weight loss, blood cultures were obtained, all of which grew Streptococcus constellatus. A transesophageal echocardiogram revealed mitral valve vegetation. After antibiotic therapy was administered, the patient's cough completely resolved. He has experienced no coughing for more than 14 months. Bacteremia in conjunction with endocarditis should be added to the list of uncommon causes of chronic cough. The mechanism of cough is unknown.

Aged↗
PubMed1995

The gelweave polyester arterial prosthesis.

OBJECTIVE: To determine the effect of the gelatin coating on the efficacy of Gelweave, a new gelatin-sealed woven polyester graft material, as an arterial prosthesis. DESIGN: In-vitro and in-vivo studies of the prosthesis. SETTING: A laboratory of experimental surgery in a university teaching institution. SUBJECTS: After in-vitro testing of the material, eight dogs were subjected to a series of in-vivo tests to evaluate the properties of Gelweave in comparison with its unsealed precursor and a commerically available collagen-coated woven polyester prosthesis. INTERVENTION: Implantation of the prosthesis as a thoracoabdominal bypass for prescheduled periods ranging from 4 hours to 6 months. MAIN OUTCOME MEASURES: Physical and chemical properties of the virgin prosthesis compared with the other two prostheses, effects of the gelatin-sealed prosthesis on healing, the hematologic characteristics of the dogs before operation and at sacrifice, microscopic studies, fibrin and platelet uptakes, prostaglandin secretion, and properties of the Gelweave grafts removed at varying periods after implantation. RESULTS: The gelatin sealant in the Gelweave prosthesis effectively reduced the water permeability of the new prototype to zero. Neither blood loss at implantation nor infection during the postimplantation period was observed. The gelatin impregnation did not cause any adverse response in the dogs and was completely lysed within 2 weeks, thus allowing encapsulation and graft healing to progress satisfactorily. After 2 weeks, the prostacyclin:thromboxane ratio was greater than 1.0, whereas the fibrin and platelet uptakes on the luminal surface of the Gelweave grafts remained low, regardless of the period of implantation. Analysis of the explanted grafts confirmed that this gelatin-sealed prototype prosthesis healed satisfactorily and no adverse biologic response occurred as a result of the gelatin coating. It maintained its biostability during 6 months in situ. CONCLUSION: The new Gelweave arterial prosthesis is ready for clinical use as a thoracic and abdominal vascular substitute.

Animals↗
PubMed1995

Reclosure of the open abdomen.

BACKGROUND: The open abdomen technique for the treatment of diffuse peritonitis has gained acceptance. Our approach has been to use the zipper technique with daily irrigations. Once the abdominal problem has resolved, the mesh and zipper are removed. Surgeons are reluctant to reoperate on patients with such prior treatment because of the anticipation of a hostile abdomen. Our study is a retrospective review of 12 patients who were treated with the open abdomen technique. At a later date, they underwent elective reoperation. STUDY DESIGN: The charts of 12 patients were reviewed. After initial injury, the patients were in the surgical intensive care unit. Reoperations were performed nine months (mean) after discharge from this facility. The reasons for reoperation were closure of enteric fistula (five patients) and closure of an ostomy (seven patients). The abdominal wall was reconstructed in nine patients. In the other three patients, the abdomen was entered through a lateral incision and the bowel was reanastomosed. RESULTS: All of the patients survived. There were five complications. Two patients had ischemic skin grafts successfully treated by hyperbaric oxygen therapy (HBO). Two patients had ischemic skin flaps that were covering mesh. They responded to HBO with minimal slough of superficial tissue. One patient had a low output fistula that closed after two weeks of total parenteral nutrition. CONCLUSIONS: A history of an open abdomen is not a contraindication to later operation. Bowel continuity can be restored and abdominal wall reconstruction can be performed safely. This can be done as early as three to four months after recovery from the original injury.

Abdomen, Acute↗
PubMed1994

Radiotherapy in the management of epidemic Kaposi's sarcoma.

PURPOSE: This study is presented to help define the role of radiotherapy in the management of epidemic Kaposi's sarcoma. METHODS AND MATERIALS: Between June 1986 and June 1993, we treated 453 patients who had acquired immunodeficiency syndrome related Kaposi's sarcoma. Two hundred fifty-two patients (55.6%) had received previous treatment for their Kaposi's sarcoma: 228 (55.3%) with interferon, and 116 (25.6%) with Vinblastine. Depending on both tumour size and location, patients were treated with extended cutaneous irradiation using 4 MeV electron beam energy and/or localized irradiation using 45-100 kV x-ray (cutaneous lesions), or 4 MV x-ray (oral tumours). A total of 5015 courses of radiation therapy was given. The intention of the treatment was closely linked to the anatomic sites. Multiple courses of treatment ranging from 10 to 20 Gy (2.5 Gy/fraction, 4 times/week) were used for Kaposi's sarcoma involving conjunctiva (n = 32 treatments), eyelids (n = 306), lips (n = 170), hands (n = 208), feet (n = 417), penis (n = 131), oral mucosa (n = 43), and anal region (n = 5). A second group including other cutaneous sites (face, trunk, limbs) was treated with a dose of 30 Gy (20 Gy in 2 weeks followed by 2 weeks rest and then a second series of 10 Gy in 1 week). RESULTS: For the first group, tolerance was generally good excluding oral cavity irradiation, with an effective palliation of symptoms (87.8% overall rate of objective responses); an enhanced mucosal reactions was noted in patients receiving oropharyngeal irradiation. For the second group, a complete regression rate of 85% was observed; tolerance was acceptable: complications were severe epidermitis with skin ulceration (5%), exsudative epidermitis (26%), dry epidermitis (60%), and varying degrees of erythema (9%). There was a significant correlation between risk of recurrence (overall recurrence rate of 71% after an average of 7.5 months) and occurrence of opportunistic infections: 85% of recurrences appeared concomitantly with accelerated course of acquired immunodeficiency syndrome. CONCLUSIONS: We conclude that radiotherapy is an efficient treatment for epidemic Kaposi's sarcoma (EKS): doses of 15.2 Gy for oral lesions and 20 Gy for lesions involving conjunctiva, eyelids, lips, hands, feet, penis, and anal region were sufficient to produce shrinkage of the tumour and good palliation of symptoms. For the other cutaneous sites, 30 Gy local field irradiation could be safely given with better short-term response. Prophylactic measures with antifungal treatment should be systematically associated with oropharyngeal irradiation, to improve tolerance to the treatment.

Acquired Immunodeficiency Syndrome↗
PubMed1994

White matter changes are correlated significantly with radiation dose. Observations from a randomized dose-escalation trial for malignant glioma (Radiation Therapy Oncology Group 83-02).

BACKGROUND: A Phase I/II randomized dose-seeking trial was performed to document the severity, time course, and significance of white matter changes seen on serial imaging scans (magnetic resonance imaging, computed tomography) associated with bis-chlorethyl nitrosourea (BCNU) and hyperfractionated cranial irradiation. METHODS: Long term survivors (> or = 18 months) were identified from a prospective randomized dose-escalation Phase I/II trial designed to evaluate twice-daily radiotherapy for supratentorial high grade malignant gliomas. All scans were reviewed by a neuroradiologist who had no information about the prescribed dose and fractionation. In the trial, patients were assigned to receive 64.8 Gy, 72.0 Gy, 76.8 Gy, or 81.4 Gy (all fractionated as 1.2 Gy twice a day [bid]), or 48.0 Gy or 54.4 Gy (both in 1.6-Gy bid fractions). Bis-chlorethyl nitrosourea was administered every 8 weeks for 1 year. Of 747 randomized patients, 177 had analyzable scans. The scans reviewed were those acquired preoperatively, immediately postoperatively, 3, 6, 12, and 18 months after radiotherapy. Radiographic endpoints included no white matter change (Grade 0), minimal patchy white matter foci (Grade 1), start of confluence of white matter disease (Grade 2), large confluent areas (Grade 3), confluence with cortical/subcortical involvement (Grade 4), leukoencephalopathy (Grade 5), and possible necrosis (Grade 6) according to the classification of F. Fazekas et al. The effects were scored relative to the baseline preoperative scans. The dose pairs of 48 Gy and 54.4 Gy, 64.8 Gy and 72 Gy, and 76.8 Gy and 81.4 Gy were grouped together for analysis (low, intermediate, and high dose, respectively). Toxicity was analyzed in three ways: Grade 2 or worse, Grade 3 or worse, and Grade 6. RESULTS: Grade 2 or worse changes were observed in 26.6, 27.6, and 40.4% of patients in the low, intermediate, and high dose groups, respectively. Grade 3 or worse changes were observed in 8.3, 20.0, and 36.5% of patients in the low, intermediate, and high dose groups, respectively. Grade 6 changes were observed in 1.6, 4.6, and 19.2% of patients in the low, intermediate, and high dose groups, respectively. No statistically significant differences were observed among treatment groups when toxicity was evaluated as Grade 2 or worse. For toxicity of Grade 3 or worse, an chi-square test revealed P values of 0.04 (low vs. intermediate dose), 0.09 (intermediate vs. high dose), and 0.0005 (low vs. high dose). With the endpoint of possible necrosis (Grade 6), P values were 0.21 (low vs. intermediate dose), 0.05 (intermediate vs. high dose), and 0.003 (low vs. high dose). The median time to radiographic appearance of an effect (15 months) was not influenced by total dose or fraction size. CONCLUSIONS: A well described toxicity scale for white matter injury was applied successfully to patients with malignant glioma treated with definitive irradiation. Severe white matter changes continued to increase significantly as the total dose of hyperfractionated cranial irradiation was escalated. The time to onset of the white matter abnormalities appeared to be independent of dose. An ongoing Radiation Therapy Oncology Group study will allow correlation of white matter injury with prospective neuropsychometric testing.

Brain↗
PubMed1994

Child nutrition, birth spacing, and child mortality.

Over half of all deaths in young children are caused by acute respiratory infections and diarrhea. Interventions have been targeted to treatment of illness, not prevention. Mortality levels have declined in response, but morbidity levels remain high. Declines in mortality have stagnated in many areas. High rates of child malnutrition are a major reason for continued morbidity and mortality from such illnesses. Case fatalities and severity of illness due to diarrhea and pneumonia are greatest in malnourished children. Improvement in feeding of young children is associated with lower incidence or severity of these and other illnesses. Efforts to improve young child feeding need to be integrated into child survival activities. Increasing durations of exclusive breastfeeding (to six months) and improving complementary feeding will promote child growth and reduce infection and mortality. These interventions are likely to enhance child spacing.

Birth Intervals↗
PubMed1994

Tyrosine ingestion during rat pregnancy alters postnatal development of dopaminergic neurons in the offspring.

It has been previously reported that tyrosine ingestion by the mother rat during gestation modifies different behavioral patterns in the adult offspring. In the present study, the action of maternal mother tyrosine ingestion on the postnatal development of the dopaminergic system of the offspring was evaluated. The offspring of tyrosine-treated mothers showed a decrease in dopamine (DA) levels during the first 15 days of postnatal life and an increase in DA levels from day 30 to adulthood. The DOPAC level and the DOPAC/DA index were higher in the tyrosine group from postnatal life to adulthood. These differences reach statistical significance in both forebrain and mesencephalon. During adulthood the DA concentration in both s. nigra and ventral tegmental area were higher in the tyrosine group than in the control group. The behavioral postsynaptic response to a DA receptor agonist (apomorphine) was higher in the offspring of tyrosine treated rats than in the control group. These data suggest that the bioavailability of the DA precursor tyrosine during gestation may modify during postnatal life DA synapsis at both pre- and postsynaptic level.

Administration, Oral↗
PubMed1994

Nervous system dysfunction among workers with long-term exposure to manganese.

Neurological disorders, bearing many similarities to Parkinson's disease, have been associated with environmental and occupational exposure to manganese (Mn). To document early nervous system dysfunction associated with long-term exposure to Mn, a battery of neurofunctional tests was administered to workers employed in Mn alloy production. Study participation was 95% (n = 115). A matched pair design was used; actively working men, with no history of workplace exposure to neurotoxins, were recruited from the region as referents. Matching was done on the variables: age (+/- 3 years), educational level (+/- 2 years), smoking status, and number of children. Stationary environmental sampling indicated that Mn levels varied widely (geometric means: Mn dust, 0.89 mg/m3; respirable Mn, 0.04 mg/m3). The alloy workers had significantly higher levels of whole blood Mn (geometric mean: 1.03 microgram/100 ml vs 0.68 microgram/100 ml); no differences were observed for urinary Mn. Univariate analysis (paired t test, Signed Rank and McNemar) and multivariate analysis of variance (Hotelling-Lawley statistic) revealed that the pairs differed on symptom reporting, emotional state, motor functions, cognitive flexibility, and olfactory perception threshold; verbal fluency, basic mathematics, reading capability, and attentional capacity were similar. These findings are consistent with current knowledge on brain Mn activity and suggest that manifestations of early manganism can be observed in well designed population studies, using sensitive testing methods.

Adult↗
PubMed1994

Theoretical and experimental behaviour of the muscle viscosity coefficient during maximal concentric actions.

The aim of this study was to calculate the theoretical variation of the nonlinear damping factor (B) as a function of the muscle shortening velocity, and then to compare the theoretical values with the experimental data obtained on both the elbow flexor and the ankle extensor muscles. The theoretical variation of the B factor was determined from a muscle model consisting of a contractile component in parallel with a viscous damper both in series with an elastic component, and by using, the characteristic equation of the force velocity curve. In this muscle model, the viscous element modelled the inability of the muscle to generate as big a contracting force (while shortening) as possible under isometric conditions. Eight volunteer subjects performed maximal concentric elbow flexions and ankle extensions on an isokinetic ergometer at angular velocities of 60, 120, 180, 240, 300 and 360 degrees.s-1, and held two maximal isometric actions at an elbow angle of 90 degrees (0 degrees corresponds to the full extension) and at an ankle angle of 0 degree (0 degree corresponds to the foot flexion of 90 degrees relative to the leg axis). From these measurements, the force and the shortening velocity values of each muscle were determined by using a musculo-skeletal model of the joint. The results showed that the theoretical behaviour of the B factor would seem to be dependent on the shortening velocity and on the parameter which varies according to the muscle fibre type composition and affects the curvature of the force-velocity curve (af).(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1994

Radiotherapy in the management of epidemic Kaposi's sarcoma of the oral cavity, the eyelid and the genitals.

From January 1987 to December 1992, 420 patients with acquired immunodeficiency syndrome (AIDS)-related epidemic Kaposi's sarcoma (EKS) were treated with radiotherapy at the oncology department in the Henri Mondor Hospital. Of these, 146 (34.7%) exhibited tumours at 186 sites; 35 were oral, 102 eyelid or conjunctival (ophthalmic), and 49 penile or scrotal (genital) sites. Most patients had received prior chemotherapy. Radiation therapy consisted of 4 MV or 45 kV X-rays, depending on tumor size and location. Doses ranged from 10 to 30 Gy, according to tumor response and toxicity. In oral lesions mucosal reactions were often observed after relatively low doses of radiotherapy. In 27 patients receiving 15 Gy, severe reactions were observed in 6 (22%), moderate reactions in 4 (15%) and mild reactions in 17 (63%). By contrast, irradiation of eyelid or conjunctival lesions and genital lesions, was well-tolerated. Treatment was generally successful in achieving good symptom palliation. Eyelid and conjunctival Kaposi's sarcoma seemed to be more radiosensitive when compared with cutaneous sites: a high objective remission rate (96%, 98/102) was observed at doses ranging from 10 to 20 Gy. Penile and scrotal lesions showed a good response to low dose radiation (complete response was scored in 34/49 patients (69.4%)). A meticulous evaluation of tolerance was necessary. Toxicity of oropharyngeal irradiation at relatively low doses is an argument for a restrictive use of this procedure in oral lesions.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Ontogenic development of brain asymmetry in dopaminergic neurons.

In the present study the right-left brain asymmetry of central dopamine (DA) systems during postnatal brain development is evaluated. DA and dihydroxyphenylacetic acid (DOPAC) levels increased from neonatal to adult life in both the forebrain and mesencephalon. This increase was not similar in the right and left brain sides. From neonatal life to adulthood a fall was observed in (a) DA percentage in the DA high-brain side in the mesencephalon and (b) DOPAC percentage in the DOPAC high-brain side in both the forebrain and mesencephalon. The percentage of lateralized rats (more than 65% of DA or DOPAC levels in either brain side) also decreased during ontogeny. Thus, biochemical lateralization decreases during ontogeny. The right-left brain correlation for DA level and DA turnover was used to evaluate the inter-hemispheric regulation of dopaminergic systems. The correlation coefficient was near to 0 during postnatal life and around -0.8 during adulthood in both forebrain and mesencephalon. Taken together, these data suggest that the ontogenic decrease of in brain asymmetry for DA or DOPAC levels is related to the postnatal development of an inter-hemispheric regulatory system that control dopaminergic neurons activity.

3,4-Dihydroxyphenylacetic Acid↗