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Biomedical subjects

L Cohen

Publications and source records attributed to L Cohen.

At least 163 records · Page 9Linked to original sources
PubMed1996

Pancreatic cancer: treatment with neutron irradiation alone and with chemotherapy.

PURPOSE: To evaluate neutron irradiation alone and with chemotherapy to treat inoperable pancreatic cancer. MATERIALS AND METHODS: Between 1977 and 1994, 173 patients (60 men, 113 women, aged 43-77 years [mean, 59 years]) with unresectable adenocarcinoma of the exocrine pancreas were treated, 106 with neutron irradiation alone and 67 with concomitant chemotherapy (fluorouracil [5-FU]). At follow-up, which was performed at 2-month intervals until death (range, 4-64 months), clinical status was recorded, noting the presence of overt metastasis and the onset of any major complications. Actuarial (Kaplan-Meier) survival tables were computed for both groups. RESULTS: For neutron irradiation alone and neutron irradiation plus chemotherapy, median survival times were 6 months and 9 months, respectively; actuarial survival rates at 3 years were 0 and 7%, respectively; major reactions (grade 3 or higher [scale of the Radiation Therapy Oncology Group and European Organization for Research and Treatment of Cancer]) occurred in 19 (18%) and 17 (25%) patients, respectively; and severe complications (grade 4) occurred in five (5%) and four (6%) patients, respectively. Most deaths were due to metastatic disease rather than to failure of local control. CONCLUSIONS: Neutron irradiation obliterated pancreatic adenocarcinoma at the primary site but has no effect on long-term survival. With more effective concomitant chemotherapy to prevent metastasis, local control of pancreatic cancer with neutron irradiation could lead to increased long-term survival.

Actuarial Analysis↗
PubMed1996

Pharmacologic management of psychiatric illness during pregnancy: dilemmas and guidelines.

OBJECTIVE: Given concerns about use of psychotropic medication during pregnancy, the authors reviewed the literature regarding the effects of prenatal exposure to psychotropic medications on fetal outcome. METHOD: A MEDLINE search of all articles written in English from 1966 to 1995 was performed to review information on the effects of psychotropic drug use during pregnancy on fetal outcome. Where sufficient data were available and when methodologically appropriate, meta-analyses were performed to assess risk of fetal exposure by psychotropic medication class. RESULTS: Three primary effects are associated with medication use during pregnancy: 1) teratogenicity, 2) perinatal syndromes (neonatal toxicity), and 3) postnatal behavioral sequelae. For many drug classes there are substantial data regarding risk for teratogenicity. Tricyclic antidepressants do not seem to confer increased risk for organ dysgenesis. The available data indicate that first-trimester exposure to low-potency phenothiazines, lithium, certain anticonvulsants, and benzodiazepines may increase the relative risk for congenital anomalies. However, the absolute risk of congenital malformations following prenatal exposure to most psychotropics is low. CONCLUSION: Exposure to certain psychotropic drugs in utero may increase the risk for some specific congenital anomalies, but the rate of occurrence of these anomalies even with the increased risk remains low. Use of psychotropic medications during pregnancy is appropriate in many clinical situations and should include thoughtful weighing of risk of prenatal exposure versus risk of relapse following drug discontinuation. The authors present disorder-based guidelines for psychotropic drug use during pregnancy and for psychiatrically ill women who wish to conceive.

Abnormalities, Drug-Induced↗
PubMed1996

Identifying patients recovering from a recent myocardial infarction who require and accept psychological care.

Using Dutch adaptations of the State-Trait Anxiety Inventory, State-Trait Anger Scale, Zung Depression Scale, and Life Orientation Test, we attempted to identify which patients recovering in the hospital from acute myocardial infarctions required and would accept psychological care. Of 63 patients who completed the relevant questionnaires, 9 required and accepted psychological care and 6 of these were correctly predicted by the criteria (sensitivity = .67). Of the 54 patients not classified as requiring and accepting psychological care, 49 were correctly predicted (specificity = .90; efficiency = .87). Noncompletion (n = 7) was positively associated with classification as requiring and accepting psychological care. An easy to administer brief questionnaire may help identify those patients with a recent myocardial infarction who, in the opinion of mental health care professionals, require and accept psychological care.

Adaptation, Psychological↗
PubMed1996

Click monitoring revisited: an on-line study of sentence comprehension.

Spoken sentence comprehension is based upon rapid and complex psychological processes, yielding a constantly fluctuating cognitive load. The aim of this study was to evaluate on-line click monitoring, a classical but poorly exploited experimental method, which should allow for an easy measurement of processing load at any chosen point of experimental sentences. In Experiments 1 and 2, we obtained longer latencies to clicks located at the boundary of reversible object relative clauses than to clicks identically located in subject relatives and to clicks located earlier within object relatives. Experiment 3 further revealed that this effect of syntactic type was specific to transposed object relatives and did not occur with normal object relatives. In Experiment 4, we observed longer latencies with semantically reversible than with irreversible sentences, but no difference between actives and passives. These results were obtained under strict control of potential lexical and phonological biases, and suggest that on-line click monitoring may be one useful tool in the study of sentence comprehension.

Adult↗
PubMed1996

Ocular motor consequences of damage to the abducens nucleus area in humans.

A patient with a complete unilateral conjugate gaze paralysis caused by a small lesion affecting the region of the right abducens nucleus, documented by magnetic resonance imaging, is reported. Eye movements were quantitatively evaluated using electro-oculography. A gaze-evoked nystagmus to the contralateral side and impairment of smooth pursuit and vestibular ocular reflex in the contralateral hemifield of movements were found. The differential diagnosis of conjugate gaze paralysis and the additional ocular motor abnormalities are interpreted in light of clinical and experimental findings.

Abducens Nerve↗
PubMed1996

Barriers to health-seeking behaviors for women infected with HIV.

There is a growing need to develop services for women with human immunodeficiency virus (HIV) infection, despite the reluctance of many to seek help. Yet, there is limited knowledge of the forces that act as barriers to health-seeking behaviors among these women. In the analysis of this focus group study of 46 women with HIV, eight distinct categories of perceived barriers to care were identified. These were: Lack of knowledge on the part of health care providers, fear of negative treatment, insensitivity of health care providers, fear by providers, lack of patient education, lack of confidentiality, lack of honesty, and blaming the victim. The women's descriptions of their experiences with health care providers are presented and discussed in the context of the potential impact of such behaviors on women's willingness to accept or continue treatment for HIV infection.

Adolescent↗
PubMed1996

[Familial cerebral cavernous angiomatosis].

Two patient with familial cavernous angiomatosis presenting with long lasting variable epilepsy with a poor therapeutic response and variable neurologic impairments are presented here. One of the numerous cavernous angiomas was resected in one case. This last patient remains asymptomatic. Familial cerebral cavernous angiomas are often numerous and disseminated in the brain, therefore clinical manifestations are very polymorphous. Moreover the course of these lesions is variable. Therefore MRI should be performed to every patient presenting with poorly understood neurological symptoms, focal or generalized epileptic seizures or absence in order to look for potentially imputable brain lesions. A reliable genetic marker might be helpful for diagnosis of this disease with a variable penetrance and autosomal dominant inheritance. Then a neurosurgical treatment should be carefully discussed if lesions are accessible and medications are poorly efficient with recurrent neurologic impairments or epilepsy.

Adult↗
PubMed1995

Retardation of mentation in depressives: Posner's covert orientation of visual attention test.

A double-key version of Posner's covert orientation of visual attention test, which involves shifting of preparation for response from one side to another, was administered to 32 depressives and 32 controls to evidence retardation of mentation in depressives and compare it to symptom-rating scales. Results showed depressives' overall response times to be consistently slower than controls. The time of maximal response preparation occurred later in depressives than in controls, showing clear evidence of pure retardation of mentation (not mixed with motor processes). This slowing of mentation was strongly correlated with observable psychomotor retardation but not with depressive severity.

Adult↗
PubMed1995

Kir, a novel Ras-family G-protein, induces invasive pseudohyphal growth in Saccharomyces cerevisiae.

Kir belongs to a novel class of Ras-family G-proteins which includes Gem and Rad. These proteins are unique among Ras super-family G-proteins since their expression is under transcriptional regulation in mammalian cells. To gain insight into the function of Kir, we took advantage of the well-defined signal transduction pathways of yeast. When kir is expressed in Saccharomyces cerevisiae, the transformants form pseudohyphae and exhibit invasive properties characteristics of yeast cells undergoing a developmental transition induced by nitrogen starvation. Analysis of pseudohyphal signaling pathway mutants suggests that the Kir-induced pseudohyphae formation requires a MAP kinase cascade involving ste20, ste11, ste7 but not ste5 gene products. Furthermore, our results are consistent with the idea that Kir functions upstream of the STE20 kinase which plays a critical role in two distinct MAP kinase cascades.

Cloning, Molecular↗
PubMed1995

[Extracorporeal lithotripsy in the treatment of upper urinary tract lithiasis].

The advent of extra-corporal shock-wave lithotripsy in the eighties totally changed management strategies for renal and ureteral lithiasis of the upper urinary tract. Currently, approximately 80% of all patients can benefit from lithotripsy with an overall success rate of about 75%. Although classical surgery has a higher success rate of about 90%, extra-corporal shock-wave lithotripsy has many advantages. First there is a very low risk of morbidity (pain, immobilization, complications) for this outpatient treatment. Second, the overall cost, including that of preventive treatment, is low as illustrated by the major reduction in the number of cases of pyonephritis on stones and of corraliform lithiasis. The apparent safety of shock-wave therapy should not mask the risk of unacceptable indications: small stones which may resolve spontaneously or inversely very large stones carrying the risk of residual fragments and renal damage. Long-term morbidity remains to be evaluated, but the management of upper urinary tract lithiasis now relies heavily on shock-wave therapy alongside conventional surgery and percutaneous or endoscopic methods.

Female↗
PubMed1995

CD14-independent responses to LPS require a serum factor that is absent from neonates.

Monocytes/macrophages and neutrophils can respond to endotoxin via a high-affinity receptor (CD14), requiring low levels of LPS (< 1 ng/ml) as well as through another pathway(s) that requires high levels of LPS (> 10 ng/ml). Both pathways result in the secretion of high levels of cytokines, such as TNF-alpha, and the up-regulation of various other effector molecules. To further define the activation of cells by LPS via a pathway that does not involve CD14, we have used an experimental model that distinguishes CD14-dependent from CD14-independent responses using saturating amounts of an anti-CD14 Ab to block the CD14-dependent response. Analysis of the ability of various individuals to respond to LPS via via both the CD14-dependent and CD14-independent pathways shows that adults can respond via both pathways; furthermore, in the presence of 100 ng of LPS/ml, the primary response is CD14 independent. In contrast to the response by adults, neonates can only respond via the CD14-dependent pathway. Further analysis has shown that the CD14-independent pathway requires a non-CD14 plasma protein present in adult plasma that is either missing or nonfunctional in neonate (cord) plasma.

Adult↗
PubMed1995

A radiation overdose incident: initial data.

PURPOSE: To estimate tolerance limits for irradiated human tissues by evaluating reactions observed in 426 patients who had received significant overdoses from an improperly calibrated cobalt unit. METHODS AND MATERIALS: A data file was designed to store essential technical and dosimetric information sufficient to analyze the response, estimate complication rates, and derive dose-response functions, using hierarchical region, system, and organ coding protocols. RESULTS: A total of 795 discrete target tissues had been irradiated in 426 evaluable subjects studied. In 183 patients who survived beyond 1 year, there were 62 (34%) with immediate severe complications in 386 irradiated sites including brain, spinal cord, skin, oropharyngeal mucosa, colon, and rectum. CONCLUSION: This unique data set includes responses to high doses and unusual fractionation beyond the range of conventional clinical experience. It provides a resource for estimating human tissue tolerance limits, for testing clinically relevant radiobiological models and for developing new optimization algorithms.

Cobalt↗
PubMed1995

Debate about parents' right to spank causes divisions among MDs.

Does spanking involve child abuse, or is it an acceptable form of discipline in Canada? Section 43 of the Criminal Code allows "reasonable" force on the part of a teacher or parent as a disciplinary measure, but an advocacy group believes that this section of the code should be repealed. However, a recent court case indicates that abolition of corporal punishment is not a black-and-white issue.

Attitude of Health Personnel↗
PubMed1995

Indoor air quality a major public-health issue, workshop told.

Indoor pollution is a major public-health issue, say representatives from government and the medical profession who participated in a recent workshop in Ottawa. Researchers are certain that indoor pollution causes many of the allergy-related problems and asthma, bronchitis, rhinitis, coughing and others respiratory problems experienced by North Americans. They urge physicians to learn about indoor air quality and to educate patients to improve their environment, particularly with respect to second-hand smoke, dust mites and mould.

Air Pollution, Indoor↗
PubMed1995

Looming public-service layoffs causing stress, other problems, Ottawa MDs report.

The federal government's attempts to curtail its deficit are going to cause thousands of layoffs in the Ottawa region, where the government is the main employer. The fear of being laid off is causing a great deal of stress among civil servants, and the signs of stress are being seen by the area's physicians. "We are seeing aggravated symptoms in people who have pre-existing psychiatric conditions," said Dr. Marvin Lange of the Royal Ottawa Hospital. "We are also seeing the emergence of new psychiatric symptoms in people who might not ordinarily have had them."

Fear↗
PubMed1995

Neutron irradiation of human pelvic tissues yields a steep dose-response function for late sequelae.

PURPOSE: Analysis of the dose-response function in normal tissues following pelvic irradiation for carcinoma of the prostate. METHODS AND MATERIALS: A homogeneous group of 136 patients with locally advanced carcinoma of the prostate were treated with the Fermilab high-energy neutron beam at three dose levels: 19, 20.4, and 21 Gy, using the same treatment plan and fractionation scheme for all patients. RESULTS: Tumor control rates were about 83% at the three dose levels studied. However, the normal tissue complication rate (late sequelae) varied with dose: 0 out of 5 at 19 Gy, 5 out of 58 (8.6%) at 20.4 Gy, and 9 out of 73 (12.3%) at 21 Gy. CONCLUSIONS: Neutron therapy to the pelvis reveals a steep dose-response function for late effects with a coefficient of variation of only 11%. This is lower than that usually observed with photons or with less uniform clinical data sets, and may be characteristic for well-planned high-LET radiotherapy.

Adult↗
PubMed1995

Congruent unilateral impairments for real and imagined hand movements.

The chronometry of imagined and actual movements was investigated in a patient with a unilateral lesion of the motor cortex. Motor imagery generated highly accurate estimates of motor performance in a variety of situations, reflecting the hypokinesia of the contralesional hand. There were parallel increases in mental and actual movement times from proximal to distal limb segments. Bimanual movements adopted the slower speed of the impaired hand in both conditions. Imagined motor sequences to the beat of a metronome predicted the maximum speed reached in actual performance. Finally, visually guided pointing showed the same target-size effects in the imagery and movement conditions. The results are in agreement with the hypothesis that common cerebral motor representations are activated when imaging and planning voluntary movements.

Aged↗