Cytotoxicity as an indicator for transport mechanism: evidence that murine bone marrow progenitor cells lack a high-affinity leucine carrier that transports melphalan in murine L1210 leukemia cells

Cytotoxicity of melphalan to murine L1210 leukemia cells was reduced to a limiting maximum value of 50% by 2-aminobicyclo[2,2,1]heptane-2- carboxylic acid (BCH), indicating that cytotoxicity is partially dependent on drug uptake by system L. L-Leucine, but not alpha- aminoisobutyric acid (AIB), completely reduced the remaining 50% of drug cytotoxicity. These results contrast with those obtained with a sensitive host tissue, the bone marow progenitor cells of the white cell series (CFU-C), in that a high-affinity leucine transport system corresponding to system L was not identified.     

Denture stomatitis with multiple intramucosal fistulae

Abstract – A hitherto undescribed clinical and histologic entity occurring in the palate of 13 denture-wearing patients is described. Clinically it is characterized by the presence of small yellowish areas in the hard palate, which on pressure yield a whitish creamy material through multiple openings. The surrounding mucosa may exhibit various degrees of erythema. The histologic changes are characterized by the presence of intramucosal fistulae lined with unkeratinized squamous epithelium. The content of the fistulae, which corresponds to the creamy material expelled, consists of desquamated epithelial cells. These changes have mostly been nodced in elderly females, all wearing maxillary dentures for many years. This entiPf is considered a type of demure stomatitis characterized by intramucosal proliferation of epithelium, possibly because of long-standing chronic irritation from dentures. The origin of the intramucosal fistulae is unknown. The fistulae are believed to originate either from the ductus of the minor salivary glands or from the surface epithelium of the palate.     

Intermediate lymphocytic lymphoma: immunophenotypic and cytogenetic findings

A detailed immunohistologic and cytogenetic analysis of 12 cases of intermediate lymphocytic lymphoma was performed. The characteristic immunophenotype of intermediate lymphocytic lymphoma was: surface IgM and IgD+, BA1+, B1+, BA2-, B2-, B4+, Leu 14+, Leu 1+, HLA-DR+, and common acute lymphocytic leukemia associated (CALLA) antigen negative. Clonal chromosome abnormalities were identified in ten cases, with structural or numerical abnormalities of chromosomes 11 or 12 in nine cases. Five cases had structural abnormalities involving the long arm of chromosome 11; three of these had translocations with chromosome 14 at band q32. Three cases had trisomy 12, and one case had a translocation involving the long arm of chromosome 12. The tenth case had a translocation involving the long arms of chromosomes 7 and 9. These characteristic immunophenotypic and cytogenetic findings suggest a close lineage relationship between intermediate lymphocytic lymphoma and small lymphocytic (well differentiated) lymphoma/chronic lymphocytic leukemia. Their differing clinical, cytologic, and architectural features suggest, however, that intermediate lymphocytic lymphoma should be considered a separate category of lymphocytic lymphoma in the International Working Formulation.     

Why should i comply? Sellers' accounts for (non-)compliance with legal age limits for alcohol sales

Background

Availability is an important predictor of early and excessive alcohol consumption by adolescents. Many countries have implemented age limits to prevent underage purchases of alcohol. However, shop-floor compliance with these age limits appears to be problematic. This study addresses the issue of non-compliance with age limits. Which measures do vendors take to avoid underage alcohol sales, and what do they report as important reasons to comply or not with age limits for alcohol sales?

Methods

Open-ended telephone interviews were conducted with store managers selling alcohol (N = 106). Prior to the interviews, all outlets were visited by an underage mystery shopper in order to measure compliance with the legal age limits on alcohol sales. The interview results are compared against actual compliance rates.

Results

Several measures have been taken to prevent underage sales, but the compliance level is low. Furthermore, open coding resulted in 19 themes, representing both valid and invalid arguments, that vendors mentioned as relevant to their decisions of whether to comply with the law. Compliance with age limits is dependent on the knowledge of the rules and the ability and motivation to follow the rules. The ability aspect in particular seems to be problematic, but in many cases, the motivation to actively comply with the age limits is lacking.

Conclusions

To enhance compliance, it is important to raise the awareness of the importance of age limits and to connect possible violations of the regulations to negative consequences.     

Activation of somatostatin-synthesizing neurons in the hippocampal formation through kindling-induced seizures

The present study was designed to determine if and to what extent somatostatin (SST) synthesizing neurons of the hippocampal formation are activated during seizures, elicited through kindling of the perforant pathway. Tissue was used and analyzed from animals which had experienced a single afterdischarge, or a stage 3 or stage 5 seizure. The protein expression of the oncogene c-fos in activated, depolarizing neurons was utilized to identify seizure-activated SST-synthesizing neurons. Combined immunocytochemical and in situ hybridization methods were used to identify these double-labeled, Fos protein, and SST mRNA-containing neurons. The results were quantified and compared across seizure stages. The resulting data demonstrate that at every stage of seizure development, a majority of SST-synthesizing neurons is activated, but that these activated SST mRNA-containing neurons represent only a minority of all seizure-activated, Fos-expressing neurons in the hippocampal formation. The data further reveal a numerical hierarchy in which the majority of double-labeled neurons is present in the hilus of the dentate, followed by the stratum oriens of CA1. It is concluded that SST-synthesizing neurons represent an integral component of the kindling activated neuronal network and, since the SST synthesizing neurons represent the minority of all seizure-activated neurons in the hippocampal formation, that this neuronal network is likely to be of considerable neurochemical complexity. & 1995 Wiley-Liss, Inc.     

Vertebral bone density in children: effect of puberty

To determine changes in bone density during growth, trabecular vertebral density and an index of spinal cortical bone were measured with quantitative computed tomography in 101 children. The children were divided by age into three groups: prepubertal, indeterminate, and pubertal. Compared with prepubertal children, pubertal adolescents had significantly higher trabecular bone density and more compact bone in the spine (P less than .001). After controlling for puberty, vertebral bone density failed to correlate significantly with age, sex, weight, height, surface area, and body mass index. The results indicate that bone density increases markedly during puberty.     

Acrylic resin-fiber composite—part I: The effect of fiber concentration on fracture resistance

This study tested the effect on the fracture resistance of acrylic resin test specimens when different amounts of fibers were incorporated in the resin matrix. The fibers used included glass, carbon, and aramid fibers, with 30 test specimens of each concentration of fibers. Transverse sections of the specimens were studied by scanning electron microscope to establish how the fibers behave in the polymerization process. The results indicated that an increase in the amount of fibers enhanced the fracture resistance of the test specimens (p < 0.001). The SEM micrographs of transverse sections of test polymerized specimens revealed void spaces of different sizes inside the fiber roving.