Stereotactic fine-needle aspiration cytology of nonpalpable breast lesions: initial experience in a tertiary-care institution.

To assess the accuracy of stereotactic fine-needle aspiration cytology in the diagnosis of nonpalpable breast lesions, this procedure was performed in 226 consecutive patients, all women, immediately before needle localization and excision of the lesions. The patients were treated at a tertiary-care hospital between December 1989 and October 1991. The cytologic results (lesion benign, atypical, suspicious or malignant or insufficient material for interpretation) were compared with the histologic findings and the degree of suspicion (low, slight or high) on the basis of mammographic examination.

The composition and function of the pulmonary surfactant system during metamorphosis in the tiger salamander Ambystoma tigrinum.

Mammalian lungs secrete a mixture of surface-active lipids (surfactant), which greatly reduces the surface tension of the fluid coating the inner lung surface, thereby reducing the risk of collapse upon deflation and increasing compliance upon inflation. During foetal lung maturation, these lipids become enriched in the primary and active ingredient, a disaturated phospholipid. However, disaturated phospholipids exist in their inactive gel-like form at temperatures below 37 degrees C and thus are inappropriate for controlling surface tension in the lungs of many ectotherms.

Dose response of Cryptosporidium parvum in outbred neonatal CD-1 mice.

Cryptosporidium parvum infectivity in a neonatal CD-1 mouse model was used to determine the dose needed to infect 50% of the population. The 50% infective dose was estimated to be 79 oocysts. It was observed that a mean oral inoculum of 23 oocysts produced infection in 2 of 25 neonatal mice 7 days postinoculation.

Alterations in CD8+ cell distribution in gut-associated lymphoid tissues (GALT) of the aging Fischer 344 rat: a correlated immunohistochemical and flow cytometric analysis.

The distribution of CD8+ phenotype (cytotoxic/suppressor) T lymphocytes in Peyer's patches and intestinal lamina propria in young adult (3-6 months) and old (24-29 months) Fischer 344 rats was examined using immunohistochemical and flow cytometric analyses. Flow cytometric analysis confirmed previous reports indicating no change with age in the proportion of Peyer's patch CD8+ cells in the rat. Immunohistochemical analysis showed discrete zones of densely stained CD8+ cells in the interfollicular areas and weakly stained cells within the follicles in Peyer's patches in young adult animals.

The role of surfactant in the static lung mechanics of the lizard Ctenophorus nuchalis.

We previously showed that the lung of the central Australian lizard, Ctenophorus nuchalis, contains a large amount of surfactant, the composition of which varies with body temperature. We now show that the specific compliance of the lungs of these lizards remains constant regardless of whether they were maintained at 10, 18, 27, 37 or 43 degrees C for 4 hours. In contrast, the opening pressure was constant up to 27 degrees C, but decreased at 37 and 43 degrees C.

Developmental and family correlates of children's knowledge and attitudes regarding AIDS.

Assessed developmental and family variables associated with children's knowledge of and emotional attitudes toward AIDS. Participants included 65 first to sixth graders from two private elementary schools and their mothers. Between-groups comparisons showed that children knowledgeable about AIDS were older and had more mature illness concepts than children who were not knowledgeable.

In vivo processing of an intron-containing archael tRNA.

In vitro studies on the processing of halobacterial tRNA introns have led to the proposal that archaeal and eukaryotic tRNA intron endonucleases have distinctly different requirements for the recognition of pre-tRNAs. Using a Haloferax volcanii in vivo expression vector we have examined the in vivo processing of modified forms of the halobacterial intron-containing tRNA(Trp) gene. As observed in vitro, changes in the exon-intron boundary structure of this pre-tRNA block processing.

Transfer RNA genes from the hyperthermophilic Archaeon, Methanopyrus kandleri.

Genes encoding the Leu (GAG), Ser (UGA), Gln (UUG) and Lys (UUU) tRNAs have been cloned and sequenced from the deep sea hyperthermophilic Archaeon, Methanopyrus kandleri. Sequences conforming to the TATA box element established for methanogen promoters are located upstream of the tRNA(Gln) and tRNA(Lys) genes. All four of the tRNA genes appear to encode the 3' terminal CCA residues of the mature tRNA.

Evolving to provide pharmaceutical care without additional resources in a university hospital.

Our department is committed to a process of continuous quality improvement focusing on delivering the best possible pharmaceutical care services. Three committees, each with representation from pharmacists and pharmacy technicians from all areas of the department, were convened in 1991 to 1992 to further identify areas for service enhancement and to plan for the future. Based on the recommendations of these committees, further expansion in ambulatory services is a priority.

Expression of the polymeric immunoglobulin receptor by cultured aged rat hepatocytes.

The Fischer rat shows an age-related loss of both hepatic blood to bile transport and secretory component-specific binding sites for polymeric immunoglobulin (Ig) A. This age-related loss of hepatic IgA receptor function is also shown by cultured hepatocytes. It is reported here that compared with young cells, binding and uptake of 125I-polymeric IgA by cultured hepatocytes was markedly reduced in cells from senescent animals.

Ageing compromises gastrointestinal mucosal immune response in the rhesus monkey.

Most research on the effects of ageing on gut mucosal immunity has been performed using rodents. However, there are inherent difficulties in the extrapolation of rodent data to humans. This study was initiated to define age-related changes in the gastrointestinal (GI) mucosal immune response in non-human primates.

Disaccharidase activity in the small intestine of susceptible and resistant mice after primary and challenge infections with Giardia muris.

The activities of four disaccharidases were examined in resistant (C57Bl/6) and susceptible (C3H/HeN) mice during the primary infection with Giardia muris and after challenge with either trophozoite extract or cysts. Significant decreases in lactase, sucrase, trehalase, and maltase activities in C57Bl/6 mice and lactase and sucrase activities in C3H/HeN mice in the anterior 25% of the small intestine were observed on day 10 after infection. The activities of maltase, sucrase, trehalase, and lactase in the jejunum of C3H/HeN mice were significantly reduced after challenge with trophozoite extract, when compared with the uninfected or infected, but not challenged animals.

Phagocytosis of Giardia lamblia trophozoites by cytokine-activated macrophages.

Phagocytosis of Giardia lamblia trophozoites by cytokine-activated and non-activated bone marrow-derived macrophages was examined in vitro. Macrophages treated with recombinant interferon-gamma (IFN-gamma) and bacterial lipopolysaccharide (LPS) ingested a significantly higher number of in vitro-grown trophozoites than untreated macrophages. Maximal uptake of parasites occurred after 4 h and 6 h of incubation where 81.

Temperature effects on ventilation and metabolism in the lizard, Ctenophorus nuchalis.

The effect of temperature upon ventilation and metabolism was measured on a breath by breath basis in the lizard Ctenophorus nuchalis. This species displayed a typical reptilian breathing pattern; groups of breaths separated by periods of breath holding. The lengths of the non-ventilatory periods (NVP) decreased as temperature increased.

The RNA component of RNase P from the archaebacterium Haloferax volcanii.

RNase P, an endoribonuclease responsible for generating the mature 5' termini of tRNA precursors, is composed of both RNA and protein. It has been demonstrated that the eubacterial RNase P RNA will, under the appropriate reaction conditions, exhibit catalytic activity in vitro. Evidence has not been obtained for catalytic activity by the RNAs of eukaryotic RNase P enzymes.

Biochemical genetics of phosphohydrolase polymorphism in Culex pipiens complex.

1. Single 4th-instar larvae were used in the investigation of alkaline phosphohydrolase (APH) variability in Culex pipiens quinequefasciatus. The genetic basis of isozyme variability was determined from genetic crosses performed with isogenic and hybrid strains of mosquitoes.

An expression vector for the archaebacterium Haloferax volcanii.

The recent development of an efficient transformation method and shuttle vectors for Haloferax volcanii has set the stage for rapid progress in archaebacterial molecular biology. We describe a shuttle-expression vector that can be selected for and maintained in either H. volcanii or Escherichia coli and permits the expression of cloned genes in H.

Recognition of exon-intron boundaries by the Halobacterium volcanii tRNA intron endonuclease.

The intron-containing tRNA(Trp) precursor from Halobacterium volcanii, like many intron-containing archaebacterial precursor tRNAs, can assume a structure in which the two intron endonuclease cleavage sites are localized in two three-nucleotide loops separated by four base pairs. To investigate the role of this structure in cleavage by the halophilic endonuclease, a series of mutant tRNA(Trp) RNAs were prepared and evaluated as substrates. We find that alterations in this structure result in the loss of cleavage at both 5' and 3' sites.

Body temperature alters the lipid composition of pulmonary surfactant in the lizard Ctenophorus nuchalis.

In any 24-h period the body temperature (Tb) of the central Australian agamid lizard, Ctenophorus nuchalis, may vary from 13 to 45 degrees C; the mean preferred Tb is 37 degrees C. We have analyzed surfactant-type lipids in lizards that underwent rapid changes in Tb from 37 degrees C to 14, 19, 27, or 44 degrees C. Lipids were extracted from lung lavage and lamellar body fractions, and phospholipids and cholesterol components were measured.

Impact of a drug-use review program intervention on prescribing after publication of a randomized clinical trial.

The effect of a drug-use review (DUR) program intervention on physician prescribing after the results of a randomized clinical trial were published was studied. A Veterans Administration (VA) cooperative study published in June 1986 showed that congestive heart failure (CHF) patients who had hydralazine and isosorbide added to their drug therapy had less mortality than patients given digoxin and diuretics with or without prazosin. Physicians with at least one CHF patient who was receiving the less effective therapy were randomly assigned to intervention and control groups.

Genes encoding the 7S RNA and tRNA(Ser) are linked to one of the two rRNA operons in the genome of the extremely thermophilic archaebacterium Methanothermus fervidus.

Analysis of gene structure in the extremely thermophilic archaebacterium, Methanothermus fervidus, has revealed the presence of a cluster of stable RNA-encoding genes arranged 5'-7S RNA-tRNA(Ser)-16S rRNA-tRNA(Ala)-23S rRNA-5S rRNA. The genome of M. fervidus contains two rRNA operons but only one operon has the closely linked 7S RNA-encoding gene.

Legal contracts.

I refer to Joe Sheridan's article (Nursing Standard December 20 - January 2) in which he considers the legal capacity of probably the most common form of contract, namely employment.

Health, equity, and reproductive risks in the workplace.

Potential exposure to occupational reproductive hazards raises complex questions regarding health and gender discrimination in the workplace. On the one hand, growing scientific evidence suggests that workplace exposures to either sex can cause a wide range of disorders ranging from infertility to adverse pregnancy outcomes. On the other hand, policies alleging to protect workers from reproductive risks have often reinforced gender inequalities in the workplace.