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Biomedical subjects

J Gross

Publications and source records attributed to J Gross.

At least 523 records · Page 29Linked to original sources
PubMedDate not supplied

Hypoxia induces different responses of striatal high- and low- affinity dopamine uptake sites.

The dopamine (DA) uptake over a concentration range from 0.03 to 100 microM was studied in S1 fractions of the rat striatum prepared from control rats and those exposed for 14 h to hypobaric hypoxia. The uptake exhibited non-Michaelis-Menten kinetics, which were evaluated by applying an equation assuming two transport sites. The high-affinity uptake site was characterized by an apparent Michaelis-Menten constant of 0.47 microM and an apparent maximal transport rate of 113 pmol/mg protein/30 s. The respective constants of the low-affinity uptake site were 52.8 microM and 1490 pmol/mg protein/30 s. One hour after hypoxia kinetic constants of the high-affinity uptake were unchanged but the maximal transport rate of the low-affinity uptake was increased by 50%. The elevated low-affinity uptake capacity may represent a means of adaptation to hypoxia allowing a faster removal of high extracellular concentrations of DA.

Animals↗
PubMedDate not supplied

Platelet phospholipid synthesis in Alzheimer's disease.

The rates of incorporation of [3H]choline and [3H]ethanolamine into membrane phospholipids of platelets from 22 drug-free Alzheimer's disease patients and 18 normal elderly controls were compared. No significant differences between groups were found. If alterations in lipid metabolism are involved in the pathophysiological processes underlying Alzheimer's disease, such alterations are not manifest in measures of radiolabeled base incorporation into platelet phospholipids.

Aged↗
PubMedDate not supplied

Dose effects of nicotine gum.

Nicotine gum has been shown to be effective in improving abstinence rates, and in reducing post-cessation withdrawal distress and weight gain. However, the dose effects of nicotine gum on these outcomes is not known. In the present study, we varied the amount of 2 mg nicotine gum prescribed to motivated quitters to explore the hypotheses (a) that motivated quitters would use more pieces of gum when coached and counseled to do so and (b) that there would be a dose-related effect of gum use on abstinence, withdrawal symptoms, and weight gain. One hundred seventy-seven volunteers were assigned to chew either 0, 7, 15, or 30, pieces per day of 2 mg nicotine gum. Biological verification of gum use and smoking abstinence were assessed in community volunteers who attended an intensive behavioral counseling program for smoking cessation while using nicotine gum for 3 months. In the survival analysis at 12 weeks, gum-group assignment was not related to successful abstinence. In the subset of 42 abstinent subjects, there was a strong positive relationship between pieces per day of nicotine gum used and saliva cotinine. However, there was substantial variability in groups of subjects reporting similar amounts of gum use. Withdrawal symptom reporting was not related to either gum use or cotinine levels. Weight gain was significantly related in a dose-dependent manner to salivary cotinine levels, but not to gum group assignment, with high and low cotinine subjects gaining on average, 4.0 and 6.6 pounds, respectively. Discussion of the use of high levels of nicotine gum is addressed. Consistent with earlier work, the study provided further support for the relationship between nicotine replacement level and post-cessation weight gain.

Dose-Response Relationship, Drug↗
PubMedDate not supplied

Nicotine-containing versus de-nicotinized cigarettes: effects on craving and withdrawal.

Nicotine exposure levels and subjective effects from smoking a de-nicotinized cigarette (Next) were examined under controlled conditions. Ten tobacco smokers smoked 20 puffs from their own brand (1.1 mg nicotine delivery, commercial cigarettes), a 0.7 mg nicotine "light" cigarette, or the Next de-nicotinized cigarette (< 0.1 mg nicotine) during independent experimental test sessions. The Next cigarette did not deliver and appreciable nicotine, did not elevate heart rate during smoking, and was rated as less satisfying than the smokers' own brand. Subjective ratings of cigarette carving and tobacco withdrawal symptoms increased during a 90 min post-smoking abstinence period. However, there were no measurable differences on these subjective ratings across the three cigarette test brands. It is concluded that nicotine can be removed from cigarettes without affecting the onset time course or intensity of cigarette cravings and other tobacco withdrawal symptoms in an acute abstinence model. Further studies to determine the subjective and physiological effects of nicotine-free cigarettes would contribute to a greater understanding of tobacco withdrawal and the processes involved in smoking maintenance.

Adult↗
PubMedDate not supplied

A comparative study of pediatric onset psoriasis with adult onset psoriasis.

Psoriasis in childhood is not uncommon. We report data collected from 223 pediatric onset and 484 adult onset psoriasis patients. In the pediatric onset psoriasis patients (POPPs), prevalence of family history was 68.2% compared to 54% in the adult onset psoriasis patients (AOPPs). Also we noticed that exacerbation of psoriasis induced by precipitating factors such as stress (50.4% in POPPs, 42. 7% in AOPPs), pharyngitis (27.9% in POPPs, 12.2% in AOPPs), and trauma (49.6% in POPPs and 38.9% in AOPPs) were more frequent in POPPs. Our data show that the frequency of spontaneous remission in POPPs was 35.3% compared to 24.3% in AOPPs. A disfiguring skin disease in childhood may have profound emotional effects. Childhood psoriasis needs special attention. To achieve a prolonged remission it is essential that children with psoriasis and their parents have an understanding of the exogenous and endogenous factors responsible for the increased morbidity of psoriasis.

Adolescent↗
PubMedDate not supplied

[Psychomotor development of newborn infants at risk with reference to the neuron-specific enolase].

In a prospective study the psychomotor development of an unselected collective of risk newborn infants up to the end of the second year of life was examined. 199 children have developed normal, 21 showed developmental abnormalities, 84 light to moderate disturbances, and 30 severe disabilities. Already in the newborn period the concentration of neuron-specific enolase in the serum was evaluated. The NSE could be an indicator of brain damage. The determined values of NSE showed a log-normal-distribution at the three times (cord-blood, first or second day of life, third or fourth day of life, and ninth to eleventh day of life). Significant relationship between the psychomotor development during the first two years of life and of NSE-concentration was not found. Nevertheless the diagnostic value of the NSE is better with a specificity of 47.7% and a sensitivity of 80.0% than those of the results of intracranial ultrasound examination or of the erythrocytic-density-test. In contrast to these results the use of the neuron-specific enolase alone for the prediction of individual prognosis of children is not be recommended.

Brain Damage, Chronic↗
PubMedDate not supplied

A comparison of drug use and adjustment in urban adolescent children of substance abusers.

Children of alcoholics and other drug abusers are at elevated risk for substance abuse and other related psychosocial problems. Adolescents with a positive family history for drug abuse or alcoholism were compared to a similar group of low-SES, urban youth who were at risk for school failure but did not report any family history of substance abuse. A survey of depression, self-esteem, behavioral competence and dysfunction, and drug/alcohol use found that, overall, adolescents with a positive family history (FHP) for substance abuse exhibited more use of illicit drugs compared to those with a negative family history (FHN). There were also a greater number of FHP cases which fell into the clinical range on the psychosocial measures of behavioral dysfunction and depression compared to FHN youth. There were differential effects for boys versus girls, with FHP girls exhibiting a greater number of problem cases. Implications for substance abuse prevention with urban youth are discussed.

Adolescent↗
PubMedDate not supplied

Myoblast transfer therapy in the treatment of ptosis: a preliminary study.

Congenital ptosis with poor levator function is now managed by frontalis suspension techniques. While this procedure is better than those used in the past, serious shortcomings exist. A technique producing more normal lid function would be a beneficial addition to surgical management. Since congenital ptosis is thought to be a focal myopathy, we investigated the potential of myoblast transfer therapy in myopathic levator palpebrae superioris. Satellite cells harvested from temporalis muscle were grown as clones, labeled with Dil, and transplanted into experimentally myopathic levator muscle of the same animal. Within 2 weeks, the injected cells were found to be incorporated into muscle fibers within the levator basal lamina. The control side appeared myopathic with very little muscle regeneration. The presence of Dil labeled muscle fibers in the experimental muscles strongly suggests their origin from the injected cells. Electron microscopy of nearby sections showed these fibers to be maturing striated muscle. We feel that the development of this technique may make autogenous myoblast transfer therapy a useful treatment for congenital ptosis and other focal myopathies.

Animals↗