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Biomedical subjects

D Cohen

Publications and source records attributed to D Cohen.

At least 505 records · Page 28Linked to original sources

[The effects of neuroleptics and social research in psychopharmacology.].

The use of neuroleptic drugs in psychiatry brought with it a wave of iatrogenic diseases and their socio-legal implications. These phenomena remain incompletely examined by the mental health professions. Social practitioners reflect in their professional literature a large ignorance of these problems. The author summarizes recent evidence on therapeutic and toxic effects of neuroleptics. Therapeutic effects are emphasized in the literature, so that toxic effects are still not well known. Ex-trapyramidal syndromes, in particular, remain poorly recognized and are often confused with psychiatric symptoms. The inability or refusal to perceive drug-induced problems from the perspective of the patient prolongs unecessary suffering. The author discusses some professional and political issues in the use of neuroleptics, and the need for a rational reexamination of the justifications for this use. Avenues for intervention as well as applied and fundamental research in social psychopharmacolo-ty are suggested.

English Abstract↗

Polyarteritis nodosa and familial Mediterranean fever: a report of 2 cases and review of the literature.

Two cases of polyarteritis nodosa (PAN) in patients with familial Mediterranean fever (FMF) are reported. These and another 11 cases found in the literature suggest that PAN occurs more commonly in patients with FMF than would be expected in the general population. Perirenal hematoma, which is surprisingly high in patients with FMF, is a life threatening complication of PAN. The diagnosis of PAN in patients with FMF may be delayed due to the similarity of the clinical manifestations of both diseases.

Adolescent↗

Deflation opening pressure of the eustachian tube.

Measurements derived from tests of the performance of the eustachian tube (ET) under a variety of normal and pathologic conditions are widely diffuse and overlap considerably. In this survey, the deflation opening pressure (DOP) of the ET was tested in 31 patients suffering either from recurrent otitis (these patients had ventilating tubes inserted) or from chronic otitis media. Oxygen was deflated from the external ear canal, through the middle ear to the pharyngeal end of the ET. The DOP was the pressure needed for the passing of the oxygen. This pressure was usually between 100 to 200 mm H2O. No difference was found in the DOP between infants and adults or between discharging ears and dry ones. A second measurement was obtained through measuring the deflation flow pressure (DFP) required for the continuous passage of oxygen through the ET. The DFP was less than the DOP by approximately 20 to 60 mm H2O, and again no difference was noted between age groups or between infected and noninfected ears. It was concluded that DOP and DFP measurements of the ET are similar in a variety of conditions and therefore cannot indicate whether the ET is normally or abnormally functioning. The existence of a linear connection between the health of the ET and its performance is not proven; hence the role of the ET in predicting the likely outcome of tympanoplasty should be assessed within a different context.

Adolescent↗

[Pulmonary complications of lymphangiography].

Pulmonary complications of lymphangiography are not uncommon. Clinical manifestations vary from asymptomatic radiological pictures to severe hemorrhagic pneumonitis or a syndrome resembling massive pulmonary embolism. We report a 17-year-old girl with Hodgkin's disease who developed pneumonitis following lymphangiography.

Adolescent↗

The V gamma locus of the human T cell receptor gamma gene. Repertoire polymorphism of the first variable gene segment subgroup.

Southern blot analysis using a genomic probe of the human TCR-gamma chain first variable gene subgroup (V gamma I) was performed on DNA samples from both parents of 36 healthy Caucasian families. Two types of polymorphisms were found in these 72 unrelated DNA samples: three repertoire polymorphisms and two restriction fragment length polymorphisms (RFLP). In all cases, Mendelian inheritance of these polymorphisms was demonstrated. The most frequent repertoire polymorphism consists in the lack of the V gamma 4 and V gamma 5 segments. In 16% of chromosomes, the Eco RI and Taq I restriction fragments corresponding to V gamma 4 and V gamma 5 were lacking, with no additional bands. In these cases, a decrease of 10 kb was observed in the Bam HI fragment containing all V gamma I segments as compared with samples containing V gamma 4-V gamma 5 segments. To better understand this polymorphism, which takes place in a previously incompletely defined region, the central part of the V gamma I region, including the polymorphic V gamma 4-V gamma 5 segments, was cloned. This allowed us to localize precisely the V gamma 5 segment and thus complete the description of the V gamma I region. A striking homology of DNA and deduced amino acid sequences is present between V gamma 2 and V gamma 4 and between V gamma 3 and V gamma 5, much higher than that observed between V gamma 2 and V gamma 3 and between V gamma 4 and V gamma 5. The differences in nucleotide sequence occur mainly in the intron and three hypervariable regions. These results strongly suggest a gene duplication relationship between the segments V gamma 2-V gamma 3 and the segments V gamma 4-V gamma 5. The most frequent RFLP documented in this study is due to the combined absence of the Eco RI and the Taq I sites located in the noncoding region between V gamma 3 and V gamma 4. The haplotypic frequence of this RFLP is 6.9% of the general population. As the gamma/delta receptor may play an important role in immunological response, the biological relevance of the high degree of polymorphism occurring in the V gamma I region, as well as its possible association with some immune disturbances, should be further explored.

Amino Acid Sequence↗

Prior exposure to medical and dental x-rays related to tumors of the parotid gland.

Findings from this population-based study in Los Angeles County suggest, for the first time, that tumors of the parotid gland are related to prior exposure to diagnostic medical and dental radiography. Responses to interviews with 408 patients with a parotid tumor (269 benign tumors and 139 malignant tumors) were compared to responses of 408 neighborhood controls. Cumulative exposure of the parotid gland from diagnostic radiography was associated with a dose-related increase in risk of malignant tumors (P for trend less than .05; relative risk for exposure to greater than or equal to 50 rad = 3.4; 95% confidence interval = 1.02-11.46). Benign tumors showed a weaker positive association, and exposure before age 20 to a major diagnostic examination (full-mouth or panoramic dental radiography or medical radiography to the head) increased risk (relative risk = 1.8; confidence interval = 1.13-2.91). This study also confirmed the association of malignant tumors with prior radiation treatment to the head or neck; 28% of these tumors are attributable to exposure of the parotid gland from diagnostic and therapeutic radiation.

Adult↗

Two distinct HLA-DR3 haplotypes are associated with age related heterogeneity in type 1 (insulin-dependent) diabetes.

Heterogeneity between two haplotypes in linkage disequilibrium with DR3: B8, C4AQOB1,BfS,DR3 and B18,C4A3BQO,BfF1,DR3, with regard to age at onset of Type 1 (insulin-dependent) diabetes mellitus, was investigated in 325 unrelated French patients (146 males and 179 females, age at onset 1 month to 29 years) who were genotyped for HLA-A, B, C, DR and Bf and 225 of whom were typed for the C4A, B complement components. A subgroup of 82 patients and 75 control subjects were tested for DR beta and DQ beta DNA restriction fragment length polymorphism. The distribution according to age at onset and the mean ages at onset were compared between patients bearing B8, DR3 (n = 58), B18,DR3 (n = 62) or other DR3 haplotypes (Bx, DR3, n = 70), the haplotype segments C4AQOB1,DR3 (n = 41) or C4A3BQO,DR3 (n = 52) and the C4 null alleles C4AQO (N = 48) or C4BQO (n = 112) alone. The B8,DR3 haplotype, its smaller segment C4AQOB1,DR3 or C4AQO alone were associated with age at onset after 6 years (p less than 0.01, less than 0.08 and less than 0.02 respectively); on the other hand, the B18,DR3 haplotype, its segment C4A3BQO,DR3 or C4BQO alone were significantly more frequent in patients aged less than 6 years at onset (p less than 0.02, less than 0.01 and less than 0.01 respectively). Accordingly, the mean age of onset was significantly lower in the latter compared with the former patients (p less than 0.02, less than 0.02 and less than 0.01 respectively). No age-related variation was observed in BX,DR3 patients and their mean age of onset was intermediate.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

The calcium channel blocker nisoldipine delays progression of chronic renal failure in humans (preliminary communication).

Chronic renal failure (CRF) patients with a stable course were asked to participate in a follow-up program in which they were randomized into two groups: 1) the placebo group taking their standard antihypertensive therapy without any calcium ion blocker: and 2) the nisoldipine group, those patients taking the calcium channel blocker nisoldipine as the only antihypertensive drug. The two groups had similar blood pressures on entering the study (151 +/- 21.3/90.7 +/- 7.4 mmHg in the nisoldipine and 146.7 +/- 18/94 +/- 9.4 mmHg in the placebo group). Their protein intake was also similar (daily average throughout the follow-up period: 0.83 +/- 0.18 g protein per kg body weight in the nisoldipine and 0.9 +/- 0.12 g in the placebo group). The patients were checked monthly. The follow-up averaged 11.1 +/- 4.8 months in the nisoldipine group and 13.7 +/- 4.2 months in the placebo group. The rate of progression of CRF, as expressed by the slope of the regression line of 1/serum creatinine versus time, decreased in the nisoldipine group from the initial (-8.03 +/- 4.91) x 10(-3) to (-5.57 +/- 5) x 10(-3) (two-tailed P-test = 0.016) after intervention. The slopes tended to become steeper in the placebo group, with an initial slope of (-4.1 +/- 3.2) x 10(-3) changing to (-7.9 +/- 5) x 10(-3) after intervention. This difference did not reach statistical significance (two-tailed P = 0.072). The rate of progression of CRF decreased in 12 of 14 patients in the nisoldipine-treated group versus 3 of 11 patients in the placebo group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Facilitation of brain stimulation reward by delta 9-tetrahydrocannabinol.

The present experiment explored whether delta 9-tetrahydrocannabinol (delta 9-THC), the psychoactive ingredient in marijuana, shares with other drugs of abuse the ability to facilitate brain stimulation reward acutely, as measured by electrical intracranial self-stimulation (ICSS). Laboratory rats were implanted with stimulation electrodes in the medial forebrain bundle, and trained to stable performance on a self-titrating threshold ICSS paradigm. delta 9-THC, at a dose believed pharmacologically relevant to moderate human use of marijuana, acutely lowered ICSS thresholds, suggesting that marijuana acts on similar CNS hedonic systems to most other drugs of abuse.

Animals↗

Dependence of the MEG on dipole orientation in the rabbit head.

In theory, a radial current dipole in a conducting sphere produces zero magnetic field outside the sphere, while a tangential dipole produces a non-zero field. Because the heads of humans and some animals resemble a conducting sphere, it follows that the magnetic field due to a radial dipole in these heads should be suppressed compared to that due to a tangential dipole. This hypothesis, which is important in the interpretation of the MEG, has never been experimentally tested. We here present a test performed in the rabbit. First, a radial dipole was placed in the rabbit head, and the magnetic field over the head due to this source was measured. Then, a similar but tangential dipole was placed in the head and again the resulting magnetic field was measured. The two magnetic fields were then compared to determine the suppression of the field due to the radial dipole. This suppression was expressed as the ratio R, the magnetic field over the head due to the radial dipole divided by that for the tangential dipole. It was found that R = 0.17 +/- 0.07, or that the magnetic field due to a radial dipole is suppressed by a factor of about 6. Therefore, to first order, the hypothesis is supported for the rabbit head. From a comparison of rabbit and human head geometry, a similar degree of suppression could be expected in the human.

Animals↗

Use of synthetic oligonucleotides for genomic DNA dot hybridization to split the DQw3 haplotype.

Comparison of two different HLA-DQ beta gene sequences from two DR4 individuals, probably corresponding to DQw3.2 (DQR4) and DQw3.1 (DQR5) specificities, has shown several nucleotide variations. Eight oligonucleotides (24 bases long), derived from these polymorphic areas, have been synthesized. Each oligonucleotide was hybridized to BamHI-digested DNA samples from eight families with HLA-DR4 individuals. Four polymorphic BamHI fragments were detected. Two of eight oligonucleotides gave a single signal (8.9 kilobases) on DQw3.2-positive haplotypes. We used one of these oligonucleotides in a genomic DNA dot hybridization and detected a hybridization signal only in DQw3.2-positive individuals. A very simple test like this allows the screening of a large population sample within a very short period.

Base Sequence↗

Serum IgG brain reactive antibodies in Alzheimer disease and Down syndrome.

The cause(s) of Alzheimer disease (AD) remain unknown. Since neurofibrillary tangles and neuritic plaques, a hallmark of AD, are also present in older patients with Down syndrome (DS), a close relationship between the two diseases has been suggested. IgG type of brain reactive antibodies (BRAs) are present in a majority of patients with AD but such studies have not been carried out in adult patients with DS. The present study was carried out to test the hypothesis that if the brain changes in older patients with DS and patients with AD are identical, the occurrence and specificity of BRAs should be similar in both diseases. The frequency of BRAs was studied in sera obtained from 21 patients with AD, 26 older patients with DS, and 20 normal control subjects using electroblots prepared from rat spinal cord proteins. Circulating BRAs were found in 57% of patients with AD, 81% of patients with DS, and 30% of normal controls. However, the pattern of BRA reactivity was different in AD and DS. In AD, antibodies reacted with the 200-kDa subunit of neurofilament triplet singly or in combination with the 150-kDa, 70-kDa or with the associated 62-kDa protein. In DS, BRAs always reacted with the 70-kDa protein, usually in combination with the 200-kDa subunit and, less frequently, in association with the other subunits. No specific pattern of antibody activity was evident in the control group.

Adult↗

Depression in family members caring for a relative with Alzheimer's disease.

The reformulated learned helplessness model of depression was tested in a study of families caring for relatives with Alzheimer's disease who did not participate in family support groups or have access to respite care. Family members who identified themselves as major caregivers, ie, those providing daily assistance to the patient, received a clinical psychiatric interview, the Beck Self-Report Depression Scale, and a modified Hammen and deMayo Attributional Style Questionnaire. The results showed that 55% of major caregivers, primarily spouses, living with an older relative with dementia experienced clinical depression. Depressed caregivers were more likely to perceive a lack of control over their situation than those who were not depressed. Contrary to the reformulated learned helplessness hypothesis, they did not perceive their situation to be the result of internal, stable, and global attributions. The results suggest the need to study depression in ecologically stressful natural settings and to develop effective clinical intervention strategies.

Adaptation, Psychological↗

Epidemiologic studies of Lyme disease in horses and their public health significance.

A serologic survey of horses in the New Jersey-Pennsylvania area demonstrated that about 10% (6.2-14.2%) have significant levels of serum antibody to Borrelia burgdorferi. However, in a highly endemic area of central New Jersey, up to 60% of the mares and yearlings samples on one farm were seropositive. In 1983, sera from this same farm exhibited only 12% positives in mares and 35% positives in yearlings. Longitudinal studies of paired sera obtained from individual yearlings over a 6-month period in 1985 showed that 34% of them declined during the period. A new clinical syndrome associated with this farm has been observed in 1985-87. In 1985 only an edema of the legs and a dermatitis were noted, in 19.2% of the foals. There was a clustering of cases on one site, where one peer group of foals was sequestered after weaning, which suggested a point source of infection other than arthropods. In 1986, 14.6% of the foals were affected, four of them with arthritis, two of which resisted antibiotic treatment for over several months' time. Experimental infection of a pony with triturated B. burgdorferi infected tick material indicated low specific antibody levels starting about the ninth day that continued for a 3-week period. When this animal was challenged 6 months later with primary B. burgdorferi cultures, a rapid and significant booster effect was evidenced within 4 days.

Animals↗