The harderian gland in mammals: The biochemical and physiological aspects

This review continues analysis of the published data on the Harderian gland in mammals (the first part described the structural properties). Here, biochemical and physiological aspects are considered, including the effect of photoperiod and sex hormones on the Harderian gland. The relationship between the Harderian and pineal glands as well as their production of biologically active indolamines and porphyrins are discussed.     

Xenoestrogenicity and dental materials

This paper discusses the xenoestrogenicity of dental materials due to 2,2-bis(4-hydroxyphenyl) propane (Bisphenol-A or BPA) and/or its derivatives. Based on a critical review of the pertinent published literature, the author concludes that there is no reason to change the indications for the clinical application of these dental materials.     

Intolerance to protein hydrolysate infant formulas: an underrecognized cause of gastrointestinal symptoms in infants

The purpose of this study was to determine the effectiveness of an amino acid-based infant formula in infants with continued symptoms suggestive of formula protein intolerance while they were receiving casein hydrolysate formula (CHF). Twenty-eight infants, 22 to 173 days of age, were enrolled; each had received CHF for an average of 40 days (10 to 173 days) and continued to have bloody stools, vomiting, diarrhea, irritability, or failure to gain weight, or a combination of these symptoms. Sigmoidoscopy with rectal biopsy was performed in all infants. The infants then received an amino acid-based infant formula, Neocate, for 2 weeks. After 2 weeks of treatment, 25 of the infants demonstrated resolution of their symptoms and underwent challenge with CHF. Of the 25 who were challenged, eight tolerated the CHF and the remainder had recurrence of their symptoms. The histologic features in these infants varied from eosinophilic infiltration to normal. We conclude that not all infants with apparent formula protein-induced colitis respond to CHF and that these infants may have resolution of their symptoms when fed an amino acid-based infant formula.     

Induction of tolerance via the respiratory mucosa

The authors examined patterns and risk factors of illicit drug use among people with disabilities by use of a random sample of 1,876 persons actively involved in vocational rehabilitation services in three Midwestern states. Compared with regional drug use data from the general population, respondents with disabilities reported higher rates of illicit drug use for nearly every drug category. Factors significantly associated with illicit drug use included level of disability acceptance, best friends' drug use, attitude of disability entitlement, self-esteem, and risk-taking. These findings provide additional insight into illicit drug use among people with disabilities. The authors discuss implications from these findings for rehabilitation and disability policy.     

System of natural killer lymphocytes in Alzheimer's type dementias

Cytotoxic activity and quantity of natural killer (NK) lymphocytes were measured in 25 patients with Alzheimer's disease (AD), in 13 patients with senile dementia of Alzheimer's type (SDAT) and in 31 normals of different age (controls). In mentally healthy elderly individuals of the same age as the patients, functional activity of a subpopulation of NK lymphocytes was significantly decreased in comparison with healthy young people, meanwhile a number of these cells wasn't changed. In patients with AD and SDAT the tendency was found to increasing of functional activity of NK lymphocytes in comparison with elderly normals, which achieved the degree of significant differences only in SDAT patients with moderate dementia. Direct dependence of cytotoxic activity of NK lymphocytes on AD duration was determined. Such correlation was not observed in SDAT. This permitted to suppose a destructive influence of lymphocytes with increased cytotoxic activity on either CNS cells or their components in AD.     

Secretion of atrial and brain natriuretic peptides from human cardiac atrial explants in culture: effect of dynorphin

We have hypothesized that metacentric and submetacentric chromosomes frequently observed in malignant canine tumors are a result of telomeric fusions. Therefore cells from a canine mammary pleomorphic adenoma were transformed with a plasmid containing the SV40 'early region', known to cause telomeric associations. Compared with non-transformed adenoma cells, the cells had a higher proliferative capacity and expressed the large SV40-T-antigen. Karyotype studies showed the conversion from a normal to an aberrant karyotype with an increase of bi-armed chromosomes resulting from fusions of acrocentric chromosomes. In addition, the length of the telomeric repeats (TTAGGG) was determined for an early and a late passage of the transformed cells by Southern hybridization. The length of the telomeric repeats was apparently longer in the 5th than in the 38th passage. In situ hybridization with a telomere-specific DNA revealed interstitial telomeric repeats in the bi-armed chromosomes. We have concluded that these findings reflect the clonal expansion of head-to-head-telomeric fusions of canine acrocentric chromosomes leading to dicentric chromosomes with a very short distance between the two centromeres. Our results support the idea that the apparent centric fusions that have been described in some canine tumors may in fact be the cytogenetic products of head-to-head-telomeric fusions.     

Indomethacin and cyclosporin together produce marked renal vasoconstriction in humans

OBJECTIVE: To test the hypothesis that an imbalance in intrarenal prostaglandins plays a role in cyclosporin-induced nephrotoxicity. METHODS AND RESULTS: Indomethacin was given in combination with cyclosporin to healthy volunteers. Cyclosporin alone (10 mg/kg twice a day) for 4 days had no effect on effective renal plasma flow (ERPF) and glomerular filtration rate but 4 days of therapy with cyclosporin (10 mg/kg twice a day) and indomethacin (50 mg twice a day) in combination resulted in a 37% fall in glomerular filtration rate and a 32% fall in ERPF. This suggests that autoregulatory mechanisms, possibly involving renal prostaglandins, may participate in counteracting the tendency for cyclosporin-induced renal vasoconstriction in humans. Cyclosporin increased systemic blood pressure acutely, and this was not influenced by indomethacin even though indomethacin on its own caused sodium retention. This suggests that, in contrast to the renal vasculature, the systemic vascular response to cyclosporin is neither augmented nor buffered by prostaglandins. CONCLUSION: The reduction in intrarenal prostaglandins clearly played a key role in the development of cyclosporin-induced renal vasoconstriction, but we could not demonstrate a role for prostaglandins or for sodium retention in the initiation of cyclosporin-induced hypertension.     

Localization of lung cancer in persons exposed to plutonium-239

Pulmonary cancer site was studied in 131 workers engaged into radioactive chemicals production and 178 examinees of control group. All examinees died in 1965-1989. Incorporation of plutonium-239 increased the number of lower lobe pulmonary cancers (upper-0.49; medium-0.06; lower-0.45) compared to 0.72; 0.03; 0.25 in control group. Ratio of cancer sites attributing to plutonium-239 was calculated for various levels of relative risk. Cancer site in the lower lobe appeared to show high probability attributing to plutonium-239 with relative risk over 1.39; in the case of upper lobe the relative risk was 3.67.     

The exponentiation formula of reliability and survival: does it always hold?

The dendritic branching pattern of cultured hippocampal neurons was analyzed to obtain mathematical parameters that fit the time-dependent growth of dendrites under limited extrinsic influence. Cultured neurons were stained with a non-toxic carbocyanine dye (diO) and pyramidal-shaped neurons that were physically separated from one another were analyzed at post-plating days 1, 2, 3, 4, 6 and 7. The geometric branching pattern of the dendrites was analyzed using a mathematical model that incorporates random effects in the form of a Galton-Watson branching process where splitting of one branch is statistically independent of the splitting of all other branches, and deterministic effects in the form of a parameter that measures the extent to which dense patterns (clusters) or sparse patterns (elongated trees) are formed. The geometric branching pattern of the dendrites was analyzed using a mathematical model that incorporates random and deterministic effects. The model parameters were estimated via the method of maximum likelihood. The data suggest that in vitro basal dendrites grow according to a purely random branching process without pronounced dense or sparse patterns, while apical dendrites tend to form elongated trees with fewer secondary bifurcations. This trend is quantified, and it depends on the culture conditions in which the neurons are grown. The quantitative assessment of various influences on dendritic growth patterns are discussed.