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Biomedical subjects

L Cohen

Publications and source records attributed to L Cohen.

At least 397 records · Page 22Linked to original sources
PubMed1986

[Malignant arterial hypertension in periarteritis nodosa. Incidence, clinicobiologic parameters and prognosis based on a series of 165 cases].

The authors studied clinical and biological data occurring in 165 patients observed during 23 years and afflicted with polyarteritis nodosa. Hypertension was present in 52 patients (31.5%) and seven of them suffered from malignant hypertension (4%). Mean age of patients (6 male, 1 female), with malignant hypertension was 38 +/- years old. Mean follow up was 49 +/- 28 months including 26 +/- 21 months after discontinuation of treatment of polyarteritis nodosa. Malignant hypertension occurred during the first year of evolution of polyarteritis nodosa. Renal insufficiency was present in 5 of 7 patients. Proteinuria was greater than 1 gr/d in 4 cases. Renal arteriography was performed in 6 patients and showed in every case renal ischemia and microaneurysms in five. In 4 patients measurements of plasma renin activity and of aldosterone were obtained. A stimulation of those hormones was demonstrated. Some symptoms of polyarteritis nodosa were present with a high incidence in case of malignant hypertension: digestive signs (6/7), orchitis (3/6). HBs antigen was present in 6 cases and hepatitis in 5. Captopril was effective in every case, alone or associated with other treatments. Follow up of hypertension went from 8 months to 4 years. At present time 6 patients are alive and one is lost of follow up. A treatment is necessary in 6 of 7 patients. Creatininemia is greater than 300 micromol/l in 4 patients. A successful kidney transplantation was performed in one case. Our study shows a close relation between malignant hypertension observed in polyarteritis nodosa, vascular nephropathy, digestive and urologic signs. Hepatitis B virus could be responsible of those manifestations.

Adult↗
PubMed1986

Elevated systolic blood pressure as a predictor of long-term cancer mortality: analysis by site and histologic subtype in 10,000 middle-aged and elderly men.

The association of a casual reading of blood pressure (BP) in 1963 to subsequent 15-year cancer mortality was examined in a cohort of 10,059 middle-aged and elderly men. Systolic BP (SBP), but not diastolic BP, predicted significantly long-term cancer mortality occurring in 369 subjects. The covariate-adjusted relative risk (RR) estimated by Cox's proportional hazard model was 1.10 [95% confidence interval (CI), 1.00-1.21]. In patients aged less than 60 at the beginning of the study, increased cancer mortality was mainly observed in association with SBP of more than 150 mm Hg. In subjects aged 60 or above, the estimated RR was 1.21 (95% CI, 1.03-1.42). Exclusion of 40 men in whom diagnosis made prior to 1963 or death occurred through 1965 did not alter the results. An excess mortality in men who reported pharmacologic treatment for hypertension while under follow-up was fully accountable by their age, BP, and smoking habits. Analysis by site suggested that the association was mainly due to increased mortality from cancer of the digestive and genitourinary organs (estimated RR's, respectively, 1.20 and 1.26; 95% CI's, respectively, 1.03-1.39 and 0.99-1.59). Analysis by histologic subtype suggests an association with adenocarcinoma (RR = 1.19, 95% CI, 1.04-1.37) but not squamous cell or transitional cell carcinomas, myeloma, lymphomas, and leukemias.

Adult↗
PubMed1986

The molecular features of verapamil that promote myocardial enzyme leakage.

The effects of verapamil (Vp) and four Vp derivatives on myocardial enzyme leakage were compared. Norverapamil (N-demethylated; D591) and acyano-Vp (the nitrile-substituted H-derivative; Sz65) produced leakage comparable to and greater than that of verapamil, respectively. In contrast, the derivative with hydroxyl substitution of all four methoxy groups (D573) and the quaternary amine salt derivative (D575) were inert. These data indicate that both lipid solubility and an ionizable amine were critical to the membrane disruptive effect of verpamil.

Animals↗
PubMed1986

Prompt termination and/or prevention of cold-pressor-stimulus-induced vasoconstriction of different vascular beds by magnesium sulfate in patients with Prinzmetal's angina.

In a group of 15 patients with Prinzmetal's angina, cold-pressor-induced anginal attacks were both promptly terminated and prevented by Mg sulfate. Cold-pressor-induced pulmonary hypertension and Raynaud's phenomenon were successfully prevented. Normalization by MgSO4 of the excessive reactive blood pressure increase in response to the cold stimulus was observed.

Aged↗
PubMed1986

Cell population kinetic parameters for acute epidermal reactions in man.

Cell population kinetic parameters for acute reactions in squamous epithelium were estimated using available data on skin tolerance doses. Roughly equivalent doses for kilovoltage radiation delivered in equal daily fractions, as reported by F. Ellis (Br. J. Radiol. 15, 348-350 (1942)) and by R. Paterson (The Treatment of Malignant Disease by Radium and X-Rays. Edward Arnold, London, 1948), were combined with data for nonstandard fractionation at longer intervals of 1 or 2 weeks. By analyzing the combined data set, well-determined parameters could be derived. The data show that repopulation, with a potential cell doubling time of about 7 days, must occur in irradiated human skin, though this may possibly be limited to no more than seven doublings. The parameters derived are distinctly different from those associated with late-reacting dose-limiting tissues. The main difference is the steeper initial slope of the computed survival curve, that is a larger J parameter (multitarget model) or a larger alpha component (linear-quadratic model).

Cell Division↗
PubMed1986

Somatosensory evoked potentials to muscle percussion in humans: upper extremity.

Cortical as well as presumably subcortical potentials were recorded from 20 normal subjects in response to mechanical percussion of the thenar eminence. Nuchal-to-frontal recordings detected an initial negative component at 21 msec, followed by positivities at 29 and 36 msec. C-prime to frontal recordings produced prominent positivities at 29 and 44 msec. Recordings over the peripheral nerve did not reveal consistent potentials. Control experiments indicate that potentials are initiated by fast-adapting muscle receptors. If additional control experiments continue to support these findings, yet another constituent of electrically evoked somatosensory potentials--which may prove useful in the definition of muscle innervation disorders--will have been identified.

Adolescent↗
PubMed1985

Response of pancreatic cancer to local irradiation with high-energy neutrons.

Seventy-seven patients with locally advanced, nonresectable, biopsy-proven adenocarcinoma of the pancreas were treated by palliative bypass surgery followed by intensive neutron beam irradiation of the primary tumor site. Three dose levels, under 20, 21 to 23, and 24 to 25 Gy, were studied with the use of a treatment plan that included all known disease within a limited target volume, generally under 2 l. Symptomatic palliation was achieved in the majority of patients. The median survival time was 6 months. One patient remained alive and well without evidence of tumor 5 years after irradiation. Two were free of tumor at autopsy (one had died of intercurrent disease and one of radiation-related complications). A common cause of death was metastatic dissemination. Complication rates were dose-dependent; life-threatening complications did not exceed 12% with doses of less than 23 Gy. Autopsies from 19 patients were reviewed. In all, the pancreatic tumor site showed extensive reactive fibrosis. Local control was achieved in two patients, but most had both residual tumor in the pancreas and metastases. Six patients had centrolobular veno-occlusive liver disease. These patients had all received the higher (22-24 Gy) neutron doses. Six patients had hemorrhagic radiation gastroenteritis. Mild skin atrophy and bone marrow hypoplasia were seen in the irradiated volumes. The kidneys and spinal cord showed no radiation effects. The authors conclude that neutron irradiation can provide a good local response with marked regression and fibrosis of the tumor. This response, coupled with many deaths due to metastases, suggests that combined treatment with neutrons and chemotherapy would be worth exploring.

Adenocarcinoma↗
PubMed1985

Is more than one application of an antifungal necessary in the treatment of acute vaginal candidiasis?

The results of all the controlled trials carried out at the Department of Genito-Urinary Medicine at the Cardiff Royal Infirmary over the past 16 years are summarized. All except one of these trials were carried out with patients having acute vulvovaginal candidiasis. One trial involved treating only patients with recurring candidal infection. In all the acute trials, there were practically no mycologic relapses 7 days after completion of treatment whatever the regimen used, but at 35 days after completion of treatment the mycologic relapse rate was in the region of 20% to 25%. It is concluded that following the elimination of any known predisposing cause of vaginal candidiasis, the intravaginal application of 500 mg of an imidazole preparation is as effective a treatment as any other regimen. In recurrent cases, monthly treatment with such a dose may be adequate to control the patient's symptoms. Mycologic relapse may not be accompanied by symptoms, but in recurrent cases there is a closer relation between mycologic relapse and symptoms.

Amphotericin B↗
PubMed1985

Sexual abuse of children--a review.

Child molestation, in and out of the family, is becoming a much better recognized serious and complex problem. General practitioners, paediatricians and casualty officers are often the first health professionals to be aware of these situations. Guidelines are given on how to recognize the presenting symptoms and how to deal with the situation holistically. The latter includes physical and psychological management of the victim, dealing with the family in this type of crisis, and a therapeutic rather than punitive approach towards the perpetrator.

Adolescent↗
PubMed1985

Clinical evaluation of neutron beam therapy. Current results and prospects, 1983.

Some 9000 patients throughout the world have been treated by some form of neutron beam therapy. These include patients with advanced nonresectable tumors in many different sites treated with a variety of neutron beam generators varying widely in beam energy. Protocols were largely nonrandomized and included both mixed beam studies (neutrons + photons) and neutrons alone in varying doses. In spite of wide variation in equipment, treatment technique, and philosophy, some consistent trends have been identified: (1) in general, the neutron results have been at least as good as those of the photon controls measured in terms of local control, although the incidence of significant side effects have been higher; (2) in none of the randomized studies conducted so far, largely comprising epidermoid carcinomas of the head and neck, has a clear survival advantage for neutrons over photon controls been demonstrated at a statistically significant level; (3) results with mixed beam studies have been uniformly equivocal, with marginally significant differences in favor of the experimental groups compared with the photon controls; (4) adenocarcinomas of the gastrointestinal tract (GI) tract, including tumors of the salivary gland, pancreas, stomach, and bowel, appear to be responsive to high linear energy transfer (LET) radiation; (5) nonepidermoid, radioresistant tumors (sarcoma of bone and soft tissue and melanoma) yield a consistantly high local control rate, with neutron irradiation strikingly superior to those reported with photon therapy; and (6) in the central nervous system, both normal tissues and tumors appear to be exceptionally sensitive to neutron irradiation, therapeutic ratios are small, and the prospect of cure remains remote. It is concluded that neutrons are efficacious for certain specific tumor types, but that essentially new study designs, based on nonrandomized matched case comparisons, will be required to prove the merit of the new modality.

Adenocarcinoma↗
PubMed1985

About the origin of cerebral somatosensory potentials evoked by Achilles tendon taps in humans.

This study examines the effects of ischemic hypoxia and cooling of the leg, muscle contraction and vibration on cerebral potentials evoked by Achilles tendon taps and posterior tibial nerve stimulation to obtain indirect evidence leading to the identification of receptors activated by tendon taps. Experiments performed during ischemia of the leg showed that these receptors lie between the ankle and the knee. Cooling of the leg showed that they are located deep in muscles or bone. Experiments performed during vibration and muscle contraction suggest that muscle stretch receptors provide the afferent input responsible for Achilles tendon tap evoked potentials. All of these experiments point to primary muscle spindles in the proximal gastrocnemius-soleus muscle belly as the main source of afferent input for evoking cerebral potentials to Achilles tendon taps in humans.

Achilles Tendon↗
PubMed1985

Fast neutrons and misonidazole for malignant astrocytomas.

Twenty-five patients with biopsy proven malignant supratentorial astrocytomas were entered into a Phase I/II study of misonidazole combined with neutron radiation at Fermilab Neutron Therapy Facility (NTF) between August 1979 and April 1981. The main objectives were to determine tissue tolerance in terms of acute and late effects, and to estimate tumor clearance and survival rates. The total dose was 18.0 Gy given in weekly fractions of 3.0 Gy over 39 days. Four hours before each irradiation, 2.5 gm/m2 misonidazole was administered orally. Patients' ages ranged from 28-69 years. Karnofsky status for most patients was 80 or 90; the lowest grade was 60. The majority of patients had glioblastoma multiforms. Most were already on steroids prior to initiation of therapy. The median survival for the whole group was 12.0 months; 25% were alive at 18 months with some neurological compromise. The median survival remained unchanged for subgroups of patients with ages between 40-60 years and with Karnofsky performance status above 80. Among the 19 patients with glioblastoma multiforme, the median survival was 10 months. Acute toxicity was within tolerable limits. Details of toxicity and tissue analysis from post mortems and second craniotomy samples are presented.

Adult↗
PubMed1985

Tolerance of the human spinal cord to high energy p(66)Be(49) neutrons.

The risk of post irradiation myelopathy was evaluated in 76 patients followed for 1-5 years after neutron irradiation of the cervical and thoracic regions. No overt myelopathy was observed. Forty-six patients received doses (central cord dose) in excess of 10 Gy, 9 received doses in excess of 12 Gy, and 5 received doses between 13 and 17 Gy, all without any evidence of spinal cord injury. On careful questioning, a subjective transient neuropathy (a tingling sensation in one extremity) was reported by 6 patients, but this was apparently unrelated to dose. A review of available literature revealed a total of 14 patients with myelopathy, 13 of whom received doses in excess of 13 Gy delivered with relatively low energy neutrons generated by the deuteron + beryllium reaction. It is concluded from these studies that the tolerance limit for the human spinal cord irradiated with high energy [p(66)Be(49)] neutrons is close to 15 Gy, above which the risk of cord injury becomes significant. Central cord doses of 13 Gy or less appear to be well tolerated with little, if any, risk of myelopathy. These conclusions are valid for a treatment time of 4 weeks or more with two or more fractions per week (9 or more fractions). The RBE for the human spinal cord irradiated under the above conditions compared with conventionally fractionated photon therapy does not exceed 4.0.

Adult↗