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Biomedical subjects

J Silverman

Publications and source records attributed to J Silverman.

At least 73 records · Page 4Linked to original sources
PubMed1994

Transthyretin sequesters amyloid beta protein and prevents amyloid formation.

The cardinal pathological features of Alzheimer disease are depositions of aggregated amyloid beta protein (A beta) in the brain and cerebrovasculature. However, the A beta is found in a soluble form in cerebrospinal fluid in healthy individuals and patients with Alzheimer disease. We postulate that sequestration of A beta precludes amyloid formation. Failure to sequester A beta in Alzheimer disease may result in amyloidosis. When we added A beta to cerebrospinal fluid of patients and controls it was rapidly sequestered into stable complexes with transthyretin. Complexes with apolipoprotein E, which has been shown to bind A beta in vitro, were not observed in cerebrospinal fluid. Additional in vitro studies showed that both purified transthyretin and apolipoprotein E prevent amyloid formation.

Amino Acid Sequence↗
PubMed1994

Enchondroma in a rhesus monkey.

A 2.5-year-old rhesus monkey was examined because of a bony enlargement of the distal portion of the right tibia. On the basis of radiographic and histologic findings, enchondroma was diagnosed. The tumor enlarged over the next 2 years, but the monkey continued to have normal use of its limb.

Animals↗
PubMed1994

Adult cat flea (Siphonaptera: Pulicidae) excretion of host blood proteins in relation to larval nutrition.

Protein content and ion composition of host blood and feces from blood-fed adult cat fleas, Ctenocephalides felis (Bouché), were examined. Total fecal protein differed slightly from host blood indicating that there was little digestion of host blood by adult fleas. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels of host blood and flea feces also revealed little digestion, as evidenced by the quantitatively and qualitatively similar protein banding patterns. Blood and fecal ion compositions also were similar, except for fleas fed in vivo on cats, where both potassium and chloride compositions of feces were approximately 50% lower. Host blood or flea feces alone were not of sufficient food value to allow > 12.5% of larvae to develop to adults. The addition of yeast or dog chow increased larval development to the pupal stage to 100% and 87.5% of first instars tested, respectively. Although some larval survival occurred with diets of dog chow + yeast (37.5%), feces + hair (20%), and feces + stratum corneum (16.7%), the period to cocoon formation was twice as long as that of larvae fed diets containing blood or flea feces + yeast. In contrast to fleas, feces of adults of two other hematophagous insects--bed bugs, Cimex lectularius L., and mosquitoes, Aedes aegypti (L.)--contained significantly less protein and more digested protein than the blood that they had fed upon. We propose that host blood excretion evolved in response to larval nutritional requirements.

Animal Nutritional Physiological Phenomena↗
PubMed1994

A longitudinal study of Alzheimer's disease: measurement, rate, and predictors of cognitive deterioration.

OBJECTIVE: This study measured the annual rate of cognitive change in patients with Alzheimer's disease and determined the effects of clinical variables on that rate. It also compared the ability of two cognitive scales to measure change over the entire range of dementia severity. METHOD: The cognitive subscale of the Alzheimer's Disease Assessment Scale and the Blessed test for information memory and concentration were given to 111 patients with Alzheimer's disease and 72 nondemented elderly comparison subjects at 6-month intervals for up to 90 months. Longitudinal changes in scores on the cognitive subscale were measured with several different methods of data analysis. RESULTS: For the patients with Alzheimer's disease, the annual rate of change in cognitive subscale scores showed a quadratic relationship with dementia severity in which deterioration was slower for mildly and severely demented patients than for patients with moderate dementia. Gender, age at onset, and family history of dementia had no effect on the rate of cognitive deterioration. The comparison group showed a slight improvement in cognitive performance over time. All data analytic methods gave similar results. The cognitive subscale of the Alzheimer's Disease Assessment Scale was more sensitive to change in both mild and severe dementia than was the Blessed test. CONCLUSIONS: These results suggest that cognitive deterioration is slow during the early and very late stages of Alzheimer's disease and more rapid during the middle stages. No clinical variables other than degree of cognitive impairment and previous rate of cognitive decline predicted rate of deterioration. These results have implications for treatment trials and attempts to identify subgroups.

Adult↗
PubMed1994

Eye movement impairment and schizotypal psychopathology.

OBJECTIVE: Eye movement dysfunction in relation to a smooth pursuit task has been documented in schizophrenic patients and in patients with the related personality disorder, schizotypal personality disorder. To investigate which quantitative measures are associated with the eye movement dysfunction and whether the dysfunction is more related to the psychotic-like or the deficit-like symptoms of schizotypal personality disorder, ratings of eye movements in several groups of subjects were compared. METHOD: The study groups consisted of 26 patients with schizotypal personality disorder, 42 patients with other personality disorders (22 who also had two or more schizotypal personality traits and 20 who had fewer than two), and 37 normal comparison subjects. Smooth pursuit eye tracking of sinusoidal and constant velocity targets was recorded by an infrared eye tracking system. Two raters evaluated pursuit gain and large and small saccades in the direction of the target and in the direction opposite to that of the target (quantitative ratings) and constant velocity (qualitative rating). RESULTS: Patients with schizotypal personality disorder and patients with other personality disorders and two or more schizotypal traits, but not those with fewer than two schizotypal traits, had significantly poorer qualitative ratings of tracking than the normal comparison subjects. Neither gain nor any of the saccadic measures significantly differed between groups. The number of large saccades in the direction of the target was the only quantitative variable that predicted low qualitative ratings. Qualitatively poor tracking was associated with the deficit-like, but not the psychotic-like, symptoms of schizotypal personality disorder. CONCLUSIONS: Patients with schizotypal personality disorder demonstrate qualitatively poorer tracking than comparison groups, and the impaired tracking is associated with deficit-like symptoms.

Adult↗
PubMed1994

The consulting psychiatrist and the polydipsia-hyponatremia syndrome in schizophrenia.

OBJECTIVE: The authors seek to extend understanding and treatment of hospitalized schizophrenics presenting with complications of polydipsia and dilutional hyponatremia. Attending physicians may ask the consultation/liaison psychiatrist to see schizophrenics with hyponatremically-induced delirium or other psychiatric syndromes. The referring physician may or may not have identified polydipsia and dilutional hyponatremia and their complications. This article will help the consultation/liaison psychiatrist recognize early evidence of water imbalance, describe evaluation, and provide somatic and behavioral treatment approaches to this life-threatening syndrome. METHOD: Over the past ten years, the authors have treated more than 100 patients with the polydipsia-hyponatremia syndrome. The authors discuss their and others' experience with drugs that help and hinder patients suffering from dilutional hyponatremia. They review current key articles from the polydipsia-hyponatremia syndrome literature including articles identified via Medline search 1985-94. RESULTS: Schizophrenics with the polydipsia-hyponatremia syndrome most commonly present with polydipsia, polyuria, urinary incontinence, cognitive, affective, and behavioral changes, seizures, or coma. Quantitating polydipsia, hyponatremia, and diurnal changes in body weight facilitate therapeutic interventions. Treatment include patient and caregiver education, drug therapies to better treat psychosis and better treat osmotic dysregulation, behavioral interventions to interdict polydipsia, and diurnal weight monitoring. CONCLUSIONS: Once recognized, acute, subacute, and chronic complications of the polydipsia-hyponatremia syndrome are readily treatable. Besides treating the patient, consultation/liaison psychiatrists can teach their medical colleagues about this syndrome. In so doing, they will enhance the quality of their patients' lives and help the internist and surgeon feel more comfortable when working with schizophrenics.

Angiotensin II↗
PubMed1994

Penetrating keratoplasty in infants with congenital glaucoma.

The efficacy of corneal transplantation in infants with corneal opacity secondary to congenital glaucoma has not been established. We retrospectively reviewed our results of nine penetrating keratoplasties performed on eight eyes of six infants who had multiple risk factors for poor prognosis: age < 2 years at the time of grafting; uncontrolled glaucoma in four eyes; concurrent lensectomy, retinal, or glaucoma surgery in five eyes; aphakia in five eyes; and an acute perforation in one eye. Six of the nine grafts (67%) remained clear during a mean follow-up of 24 months (30 months in eyes with clear grafts). Development of ambulatory vision or better occurred in six of eight (75%) eyes after corneal transplantation and treatment of refractive errors and amblyopia. Graft failure occurred in three eyes--two from corneal decompensation, and one from homograft rejection. Complications included one total retinal detachment, one case of Streptococcus pneumoniae keratitis, and three cases that lost intraocular pressure control, requiring further glaucoma surgery. We conclude that useful vision can be achieved after penetrating keratoplasty even in some high-risk infants with congenital glaucoma.

Cataract Extraction↗
PubMed1993

CSF homovanillic acid in schizotypal personality disorder.

CSF concentrations of homovanillic acid (HVA) were measured in 10 patients with schizotypal personality disorder and 14 patients with other personality disorders. The patients with schizotypal personality disorder had higher CSF HVA concentrations than the patients with other personality disorders. Furthermore, the psychotic-like schizotypal symptoms correlated positively with the CSF HVA concentrations. These results suggest a central dopaminergic dysfunction associated with the psychotic-like symptoms of schizotypal personality disorder.

Adult↗
PubMed1993

Morbidity risk for alcoholism and drug abuse in relatives of cocaine addicts.

The morbidity risks for alcoholism in the first-degree relatives of a cohort of male cocaine addicts with or without alcoholism comorbidity were studied. Of the 71 patients who participated in our study, 40 (56.3%) had a history of alcoholism and 37 (59.1%) a history of opioid abuse. Twenty-two patients (30.1%) also met criteria for a lifetime diagnosis of a major psychiatric disorder. Significant increases in morbidity risks for alcoholism were found among male relatives of cocaine addicts with comorbid alcohol dependence when compared with relatives of cocaine addicts with no alcohol comorbidity. Among fathers, risks were .69 vs .32 (z = 2.98, p < .003). Among brothers, risks were .38 vs .15 (z = 2.35, p < .03). Significantly increased risks were also observed in male relatives when probands with a psychiatric diagnosis were excluded from the analyses. Among female relatives, increases in morbidity risks were found but they failed to reach statistical significance. Two interpretations are consistent with these findings. One of these interpretations is that alcoholism is a disorder distinct from other addictions and has its own mode of transmission. The second interpretation is that the transmission of substance use disorders lacks specificity and that the substances selected are influenced by sociocultural or biological factors.

Adult↗
PubMed1993

A review of laboratory animal anesthesia with chloral hydrate and chloralose.

Chloral hydrate (CH) and alpha-chloralose (CS) are often used to anesthetize laboratory animals although, to our knowledge, there have been no controlled studies of their anesthetic or analgesic effects. Induction of and recovery from anesthesia can be stressful, and anesthesia and analgesic quality have been questioned. Intraperitoneal (i.p.) administration of CH has resulted in adynamic ileus and peritonitis in rats, gastric ulcers in rats, and peritonitis in swine. Light anesthesia is induced in rats. In dogs, CH induces sedation to deep anesthesia when given intravenously. Gastric irritation in dogs can occur when CH is given orally. Chloral hydrate is considered a good sedative-hypnotic for farm animals. Intravenously administered CS anesthetizes dogs and cats for 5 to 10 hours, but the animals may require respiratory support. Chloralose appears to be a satisfactory anesthetic for dogs when stage III thiobarbiturate anesthesia is first induced. It is difficult to gauge the depth of anesthesia and analgesia with CS. In our clinical experience with swine and calves, CH given i.p. leads to adynamic ileus. We have found that CS given i.p. causes an inflammatory response in guinea pigs, rats, and calves. We observed that CS analgesia varies with the type of surgical procedure performed. Based on a literature review and our clinical experience, we suggest that CH or CS anesthesia should be preceded by administration of barbiturates, opioids, alpha-2 agonists, or phenothiazine tranquilizers. Chloral hydrate should only be used as a sedative or hypnotic for dogs; CS should not be used as a sole anesthetic agent. Neither drug should be used i.p. for survival surgery.

Anesthesia↗
PubMed1992

Induction of proliferative lesions of ventral prostate, seminal vesicle, and other accessory sex glands in rats by N-methyl-N-nitrosourea: effect of castration, pretreatment with cyproterone acetate and testosterone propionate and rat strain.

Wistar (Cpb:WU), F344 or Sprague-Dawley rats were sequentially treated with cyproterone acetate (CA) for 21 days, testosterone propionate (TP) for 3 days, followed by a single i.v. injection of N-methyl-N-nitrosourea (MNU). One group of Wistar rats was castrated 4 weeks after MNU injection, and another group 58 weeks after MNU, when the first prostatic carcinoma was detected. Control groups received only CA + TP, CA, MNU, or they remained untreated. Early or late castration inhibited the development of atypical hyperplasia of the ventral prostate in Wistar rats. This lesion was induced by the CA + TP + MNU treatment in F344 rats, but not Sprague-Dawley rats; in Wistar rats, it was induced by CA + TP treatment, irrespective of whether MNU was given. Hypertrophic-hyperplastic lesions of the seminal vesicle were induced by MNU, irrespective of pretreatment, and their development was prevented by early castration and inhibited by late orchiectomy. Dorsolateral prostate carcinomas and preneoplasia occurred only in low incidence in Wistar and Sprague-Dawley rats. These lesions were absent in F344 rats that had received treatment with CA + TP + MNU. No dorsolateral prostate (pre)neoplasia was found in Wistar rats subjected to early orchiectomy, but rats castrated at 58 weeks had an incidence similar to that for the intact group treated with CA + TP + MNU. This finding supports the contention that androgens are required for the development of MNU-induced prostatic cancer in rats but that advanced carcinomas are androgen insensitive. Differences in incidence and localization of prostatic proliferative lesions between F344 and Wistar rats and between dorsolateral and ventral prostate could not be explained by differences in epithelial cell proliferative responses to CA + TP treatment at the time of MNU injection, since they were similar in ventral and dorsolateral prostate and were more prominent in F344 rats than in Wistar rats. DNA damage as estimated by MNU-induced unscheduled DNA synthesis also did not differ between dorsolateral and ventral prostate.

Androgens↗
PubMed1992

The lipid composition of milk from mice fed high or low fat diets.

Total fatty acids and the proportions of methyl esters of individual fatty acids were measured in mouse milk. Pregnant mice were fed either a high fat (HF) diet or a low fat (LF) diet from 14 days of gestation. After parturition, each dam was milked once a day for a period of 18 days. The mean total fatty acid concentration over the entire study period was 110 mg/g of milk (approximately 11.7% fat as triglyceride) for both dietary treatment groups. During days 2 to 6 postpartum, the mean total fatty acid concentration for dams fed HF diet was lower than for the LF group. Although the concentration of total fatty acids of mouse milk was not affected by the level of dietary fat fed to the dam, several variations in the proportions of individual fatty acids were observed.

Animals↗
PubMed1991

Body weights of C3H/HeN mice fed semipurified or commercial diets of different fat content.

Oncology studies often require specially formulated diets to be fed to laboratory animals. To determine the effect of dietary fat on body weight, C3H/HeN mice were carefully assigned by weight into three groups. The first group was fed a high-fat semipurified diet (23% fat by weight) from 21 to 73 days of age then returned to a low-fat semipurified diet (5% fat by weight). A second group was fed the low-fat diet from 21 to 73 days of age, then the high-fat diet until 129 days of age, then returned to the low-fat diet. A final group was fed a 4.5% fat commercial diet for the entire 193-day study. The results showed that the mice fed the semipurified diets did not differ significantly from each other in weight over the course of the study but did differ significantly between 21 and 73 days of age, possibly from a taste preference for the high-fat diet. Mice fed the commercial diet always weighed significantly less. It was estimated that mice fed the commercial diet consumed more food and were less efficient in their food utilization. Mice should be carefully assigned, by weight, into experimental groups, and all groups, including untreated controls, should be fed the same type of diet.

Analysis of Variance↗
PubMed1991

Hydramethylnon uptake by Blattella germanica (Orthoptera: Blattellidae) by coprophagy.

Blattella germanica (L.) that were fed hydramethylnon bait produced residues that were toxic to exposed conspecifics. Insecticidal activity was traced to the feces of treated insects by feeding radiolabeled material, where approximately 50% of the recovered radioactivity was unmetabolized parent compound. Ingestion of toxicant-laden feces by all life stages was evident, but the effect of this behavior was greatest on early instar nymphs. Baits containing toxicants with delayed activity, such as hydramethylnon, probably affect cockroach field populations indirectly through coprophagy.

Animals↗
PubMed1991

Perimyositis with perineuritis and myofiber type grouping in the eosinophilia myalgia syndrome associated with tryptophan ingestion.

Skeletal muscle biopsies from five patients with severe myalgias, peripheral eosinophilia, and a recent history of L-tryptophan ingestion were analyzed. Perimysial inflammation, predominantly mononuclear with variable numbers of eosinophils was seen (in five of five patients), which was perineurial (in three of five) and perivascular (in five of five) in location. Grouping of the myofiber types was identified by enzyme histochemistry in two of four patients; fresh muscle for histochemical studies was unavailable from one patient. An occasional degenerating myofiber was seen in only one patient, who was still ingesting L-tryptophan at the time of biopsy. No vasculitis was seen. The focus of muscle injury in this syndrome appeared to be the perimysium and, in particular, the perineurial and perivascular connective tissue.

Adult↗
PubMed1991

Caffeine and spontaneous abortion of known karyotype.

We tested associations of caffeine from beverages with spontaneous abortions of known karyotype. Spontaneous abortions (cases) were classified as chromosomally normal (n = 510) or chromosomally aberrant (n = 389) and, within the latter category, by type of aberration (237 trisomies, 54 monosomies X, 49 triploidies, 49 others). Controls registered for prenatal care before 22 weeks gestation and delivered at 28 weeks or later (n = 1,423). Caffeine intake in the perifertilization period did not differ among case groups and controls. For the highest category, 225+ mg/day, odds ratios (OR), adjusted for payment group and maternal age, were 1.0 for chromosomally normal cases, 0.9 for trisomies, 1.6 for monosomies X, and 0.8 for triploidies. Caffeine intake during pregnancy was tested for associations with chromosomally normal loss using the chromosomally aberrant cases to provide a robust comparison group. Although the proportion of subjects with intake of 225+ mg/day of caffeine intake in the perifertilization period does not influence the risk of chromosomally normal loss or trisomy. For monosomy X and triploidy, no strong associations were observed, but numbers were insufficient to rule out moderate effects. For caffeine intake during pregnancy, we found little evidence to support an influence on chromosomally normal loss.

Abortion, Spontaneous↗