Michael Wheeler

Glycine-gated chloride channels in neutrophils attenuate calcium influx and superoxide production

Recently, it was demonstrated that liver injury and TNF‐a production as a result of endotoxin (lipopolysaccharide, LPS) were attenuated by feeding animals a diet enriched with glycine. This phenomenon was shown to be a result of, at least in part, activation of a chloride channel in Kupffer cells by glycine, which hyperpolarizes the cell membrane and blunts increases in intracellular calcium concentrations ([Ca2+]i) similar to its action in the neuron. It is well known that hepatotoxicity due to LPS has a neutrophil‐mediated component and that activation of neutrophils is dependent on increases in [Ca2+]i. Therefore, the purpose of this study was to determine if glycine affected agonist‐induced increases in [Ca2+]i in rat neutrophils. The effect of glycine on increases in [Ca2+]i elicited either by the bacterial‐derived peptide formyl‐methi‐onine‐leucine‐phenylalanine (FMLP) or LPS was studied in individual neutrophils using Fura‐2 and fluorescence microscopy. Both FMLP and LPS caused dose‐dependent increases in [Ca2+]i, which were maximal at 1 μM FMLP and 100 μg/ml LPS, respectively. LPS increased intracellular calcium in the presence and absence of extracellular calcium. Glycine blunted increases in [Ca2+]i in a dose‐dependent manner with an IC50 of ~0.3 mM, values only slightly higher than plasma levels. Glycine was unable to prevent agonist‐induced increases in [Ca2+]i in chloride‐free buffer. Moreover, strychnine (1 μM), an antagonist of the glycine‐gated chloride channel in the central nervous system, reversed the effects of glycine (1 mM) on FMLP‐ or LPS‐stimulated increases in [Ca2+]i. To provide hard evidence for a glycine‐gated chloride channel in the neutrophil, the effect of glycine on radioactive chloride uptake was determined. Glycine caused a dose‐dependent increase in chloride uptake into neutro‐phils with an ED50 of ~0.4 mM, an effect also prevented by 1 μM strychnine. Glycine also significantly reduced the production of superoxide anion from FMLP‐stimulated neutrophils. Taken together, these data provide clear evidence that neutrophils contain a glycine‐gated chloride channel that can attenuate increases in [Ca2+]i and diminish oxidant production by this important leukocyte.—Wheeler, M., Stachlewitz, R. F., Yamashina, S., Ikejima, K., Morrow, A. L., and Thurman, R. G. Glycine‐gated chloride channels in neutrophils attenuate calcium influx and superoxide production. FASEB J. 14, 476–484 (2000)

Sex Differences and Individual Differences in Cognitive Performance and Their Relationship to Endogenous Gonadal Hormones and Gonadotropins

Sexually dimorphic cognitive performance in men (n=42) and women (n=42) was related to testosterone, estradiol, progesterone, luteinizing hormone, follicle-stimulating hormone, and sex hormone binding globulin, measured in 10-ml blood samples collected between 0900 and 1030 and, among women, during the follicular phase of the menstrual cycle. Significant sex differences favored men on spatial tasks (Mental Rotation and Judgment of Line Orientation) and on an inhibition task and favored women on a verbal task (category fluency). However, there were no significant relationships between any of the hormones and cognitive performance, suggesting that there are few, if any, consistent, substantial relationships between endogenous, nonfluctuating levels of gonadal hormones or gonadotropins and these cognitive abilities in men or women.

Role of Cell-Free Plasma DNA as a Diagnostic Marker for Prostate Cancer

Abstract: Recent evidence has shown elevated levels of cell‐free plasma DNA in cancer patients. The aim of the present study was to quantify and compare the levels of cell‐free plasma DNA in patients with prostate cancer, prostatic intraepithelial neoplasia (PIN), and benign prostatic hypertrophy (BPH) to examine if it offered a useful diagnostic test. Blood samples were obtained from 37 patients attending a clinic for prostate biopsies. Samples were taken prior to biopsy, within 1 hour of the biopsy, and then 2 weeks later. DNA was extracted using a QIAamp blood kit (Qiagen) and plasma DNA measured, in genome equivalents/milliliter plasma (GE/mL), using real‐time quantitative PCR for the β‐globin gene. Prior to biopsy, plasma DNA concentration in BPH patients was 936 GE/mL (median; range: 633–2074 GE/mL), while cancer and PIN patients had significantly higher levels of DNA at 1734 GE/mL (median; range: 351–3131 GE/mL; P= 0.01) and 1780 GE/mL (median; range: 1514‐2732 GE/mL; P= 0.04), respectively. Comparison of plasma DNA concentration before and after biopsy showed that 60 minutes after biopsy values were significantly higher in both BPH (1494 GE/mL; range: 613‐2522 GE/mL; P= 0.029) and cancer (2758; range: 1498‐5226 GE/mL; P= 0.007) patients. ROC analysis of the data indicated a sensitivity of 85% and a specificity of 73% when DNA concentration of 1000 GE/mL was taken as an indicator of malignancy or PIN. The data suggest that quantification of cell‐free plasma DNA may have an important diagnostic role in distinguishing benign and malignant prostate disease.

WEIGHT GAIN AND REPRODUCTIVE FUNCTION: ULTRASONOGRAPHIC AND ENDOCRINE FEATURES IN ANOREXIA NERVOSA

Pelvic ultrasonographic measurements and reproductive hormone levels in 36 patients with anorexia nervosa were followed as they gained weight during inpatient treatment. In 24 patients who were severely malnourished (69% of premorbid weight) the ovaries were small and amorphous and the levels of LH, FSH and oestfadiol were very low. Weight gain led to the appearance of multifollicular ovaries when levels of LH and oestradiol remained low but FSH levels had increased resulting in an LH: FSH ratio of less than 1. The emergence of a dominant follicle in 19 patients after weight gain (to 97% of premorbid weight) was accompanied by an increase in uterine area and associated with increased levels of LH and oestradiol and an LH: FSH ratio greater than 2. Among these patients with a dominant follicle at peak weight, 11 menstruated within a month of discharge.

CYSTIC OVARIES: A PHASE OF ANOREXIA NERVOSA

The ultrasonographic appearance of ovaries and uterus during weight-gain in patients with anorexia nervosa is described. In 11 patients who had sequential scans, ovarian volume on admission was considerably smaller than that of normal women but increased logarithmically with weight-gain. When body mass index (BMI) reached 17 kg/m2, ovaries were shown to contain multiple small cysts in all cases. In 5 patients further weight-gain led to the appearance of a dominant cyst; average BMI was approximately 19 kg/m2 at this stage. The changes in ovarian morphology resembled those of normal pubertal development. These results lend support to the suggestion that hypothalamic-gonadal axis dysfunction in anorexia nervosa is a concomitant of starvation; in the management of infertility, an ultrasonographic appearance of cystic ovaries should alert the clinician to the likelihood of undernutrition as the primary disorder in need of treatment.

Androgen status in healthy premenopausal women with loss of libido

Androgen deficiency may contribute to female sexual dysfunction and loss of libido. The role of the active metabolite of testosterone, dihydrotestosterone (DHT), in these conditions is uncertain. The aim of this study was to determine the role of androgens and DHT in the etiology of loss of libido in healthy women. We studied 29 premenopausal women with reduced libido (subjects) and 12 healthy females (controls). They were aged 18 to 45 years and in a stable heterosexual relationship. At 9 a.m. we took venous blood in the follicular phase for serum estradiol, total testosterone, and DHT, dehydroepiandrosterone sulfate (DHEAS), and SHBG levels. Subjects were interviewed by a psychosexual counsellor. Using the modified Wilsons sexual fantasy questionnaire (Baumgartner, Scalora, & Huss, 2002) and sexual satisfaction by Golombok-Rust Inventory of Sexual Satisfaction (GRISS Rust & Golombok, 1985, 1986) we assessed sexual drive. The total testosterone and DHT levels (mean ± SD) were respectively 0.97 ± 0.38 mmol/L and 0.76 ± 0.37 nmol/L in subjects and 0.97 ± 0.41 mmol/L and 0.77 ± 0.15 nmol/L in controls. The SHBG and DHEAS were respectively 65 ± 42 mmol/L and 3.76 ± 1.0 umol/L in subjects and 65 ± 29 mmol/L and 3.67 ± 2.6 in controls. The scores of the Wilson questionnaire and GRISS were respectively 21 ± 14.1 and 5 ± 2.1 in subjects and 35 ± 14.8 & 2 ± 1.2 in controls. Subjects were more likely than controls to have low income (48% versus 8%, p < 0.02), a minor illnesses (57% versus 17%, p < 0.02), a history of depression (57% versus 8%, p = 0.025) and to report sexual problems in their partners (24% versus 0%, p = 0.053). Loss of libido in otherwise healthy women may be related to relationship problem, depression, psychosocial factors, and sexual dysfunction in the partner but do not appear to be related to androgen status.

Malignant pulmonary lymphoproliferative angiitis. A monoclonal neoplasm

A 55‐year‐old female developed a rapidly fatal, infiltrative, bilateral pulmonary disease. Open lung biopsy and subsequent autopsy revealed diffuse involvement by a malignant lymphoproliferative condition showing a striking angiocentric and angioinvasive pattern. This feature, together with microscopic involvement of hilar lymph nodes, bone marrow, spleen, and other viscera suggested lymphomatous transformation of lymphomatoid granulomatosis (LYG). The paucity of necrosis and of the typical polymorphic infiltrate was at variance with the classical description of that condition; however, the bilaterality of the process and the distinctive angioinvasive growth pattern were unlike the typical primary pulmonary lymphoma. Plasmacytoid cells were observed both by light and electron microscopy. Immunohistochemical evaluation characterized this disease as a monoclonal lymphoproliferative malignancy.

Emerging Techniques in Biomedical Research and Their Application to Alcohol Toxicity

This article represents the proceedings of a symposium at the 2002 RSA-ISBRA Meeting in San Francisco. The chairs were Vinood B. Patel and Victor R. Preedy. The presentations were (1) Macromolecular structural analysis, by Vinood B. Patel; (2) Profiling and imaging of proteins in tissue sections using mass spectrometry as a discovery tool in biological research, by Pierre Chaurand and Richard M. Caprioli; (3) The use of SELDI ProteinChip trade mark arrays, by Brian M. Austen, Emma R. Frears, Francesca Manca, and Huw Davies; (4) DNA hybridization array technologies, by Kent E. Vrana; and (5) Adeno- and adeno-associated viral mediated gene transfer approaches for alcoholic liver disease, by Michael Wheeler. Concluding remarks were by Victor R. Preedy.

A novel unsupervised initial pattern recognition algorithm based on wavelet transform and window selection

This paper presents an unsupervised initial pattern recognition approach to determine spectral regions contributing most to intrinsic clustering patterns in nuclear magnetic resonance (NMR) spectra associated with a given pathological stimulus using a small number of realizations based on wavelet transform coupled with a window selection algorithm. Results of different choices of window size are given. The pattern recognition algorithm proposed in this paper can be used as the first step in metabolomic data analysis followed by future supervised algorithms to refine potential biomarkers characterizing tissue-specific lesions further within these regions.

Abbott Architect™ i2000 Analyzer An Evaluation of the Reproductive Peptide Hormone Assays:

FIGURE 1 OF ANALYZER Table 1 gives a brief description of the ARCHITECT family which is designed to accommodate a wide range of laboratory workloads as well as to provide both immunoassay and clinical chemistry testing (c800(JTM). The i2000 and c8000 may be linked directly together to a maximum of four analyzers, in a variety of combinations, to meet the large workload needs of major hospitals. For example, four i2000s may be linked together to form an i800(JTM or, two i2000s may be linked to one or two c8000s to give a c80001i400(JTM and a .ieaoo»I i400(JTM respectively. The modular system provides total automation of a wide range of analyres on a single tracking system operated by a single work station. Therefore, the need to aliquot specimens and move specimens between different analyzers is reduced. There is more economical use of specimens as only one dead space has to be considered. Finally, because the analyzers are directly linked together they occupy a smaller footprint than linking individual instruments via an independent specimen tracking system. The ARCHITECT family provides flexibility as the system can be adapted to the customers needs, and scalability as the system may be upgraded as the laboratorys workload increases. This may be done without the need to change reference ranges as the same immunoassay technology is used on all the immunoassay instruments. The system also uses a common processing unit so that the basic operating and management procedures are the same across instruments. Therefore, introduction of a different analyzer from the ARCHITECT family requires little training and no loss in operating time. The ARCHITECT i2000 is the first of the family to be launched onto the market. Chemiluminescent immunoassay technology is used incorporating a very stable patented acridinium derivative tracer. This has enhanced light emission giving greater analytical sensitivity and extended dynamic ranges. Calibration of