Antiasthmatic activity of the second-generation phosphodiesterase 4 (PDE4) inhibitor SB 207499 (Ariflo) in the guinea pig

We evaluated the airway activity of the novel phosphodiesterase type 4 inhibitor SB 207499 [Ariflo; c-4-cyano-4-(3-cyclopentyloxy-4-methoxyp henyl-r-1-cyclohexane carboxylic acid)], in the guinea pig. Ovalbumin (OA)-induced contractions of guinea pig isolated tracheal strips were inhibited by SB 207499 with an EC50 of 1 microM but had little or no effect on exogenous agonist-induced contraction, which suggests that its effect on OA-induced contraction in vitro is primarily due to inhibition of mediator release from mast cells. In anesthetized guinea pigs, SB 207499 inhibited OA-induced bronchoconstriction with i.v. and p.o. ID50 values of 1.7 and 17 mg/kg, respectively. At 1, 3 and 6 hr after SB 207499 (30 mg/kg p.o.), OA-induced bronchospasm was inhibited by 92%, 70% and 58%, respectively, corresponding to elevated plasma concentrations of 1.62 +/- 0.19, 1.65 +/- 0.29 and 0. 93 +/- 0.24 microg/ml, respectively, of SB 207499. SB 207499 also inhibited house dust mite-induced bronchoconstriction (ID50 = 0.9 mg/kg i.v. and 8.9 mg/kg p.o.). In contrast to its lack of bronchorelaxant activity in vitro, SB 207499 inhibited bronchospasm induced by i.v. leukotriene D4 (LTD4) [ID50 = 3 mg/kg i.v.]. The bronchorelaxant effect of i.v.-administered SB 207499 was at least additive with that of salbutamol in reversing infused histamine-enhanced airway tone, but it did not alter base line or enhance salbutamol-induced cardiovascular effects. In conscious guinea pigs, SB 207499 (10 or 30 mg/kg p.o.), 1 hr before antigen or LTD4 challenge, markedly reduced bronchospasm and subsequent eosinophil influx as measured by bronchoalveolar lavage 24 hr after provocation. SB 207499 administered after OA or LTD4 challenge also reduced airway eosinophilia measured at 24 hr after OA challenge or 96 hr after LTD4 challenge. These results, coupled with the broad anti-inflammatory activity of SB 207499 previously described (Barnett et al., 1998), suggest that SB 207499 will be useful in the treatment of asthma and other inflammatory disorders.     

Terminal deoxynucleotidyl transferase expression during neonatal life alters D(H) reading frame usage and Ig-receptor-dependent selection of V regions

During neonatal life, Ig diversity is limited in many respects. The absence of terminal deoxynucleotidyl transferase (TdT) expression with the consequent lack of nontemplated addition during the neonatal period, coupled with the predominant usage of a single D(H) reading frame (RF), leads to severe limitations of diversity in the CDR3 region of Ig heavy (H) chains. The neonatal Ig H chain repertoire is also characterized by restricted V(H) usage, with predominant expression of certain V(H) segments, such as V(H)81x, that are rarely evident during adult life. In this report, we examine the effect of enforced TdT expression on the neonatal repertoire of V(H)81xDJ(H) rearrangements. We find that TdT synthesis abrogates D(H) RF bias during the fetal/neonatal period through a Ig-receptor-independent mechanism. These findings suggest that D(H) RF bias during neonatal life is determined largely by homology-directed joining. We also find that TdT synthesis alters the selection of productively rearranged V(H)81xDJ(H) alleles in the neonatal spleen through a Ig-receptor-dependent mechanism. Analysis of predicted CDR3 amino acid sequences indicates that positive selection of V(H)81x-encoded H chains is correlated with the presence of a consensus sequence immediately adjacent to the V(H) segment. These data support the hypothesis that the CDR3 region is critical in determining the ability of V(H)81x-encoded H chains to form functional receptors that support positive selection of B lymphocytes. Together, our results demonstrate that TdT can indirectly influence the Ig repertoire by influencing both receptor-dependent and receptor-independent selection processes.     

Screening calcaneal ultrasound and risk factors for osteoporosis among lesbians and heterosexual women

We compared calcaneal ultrasound measurements (speed of sound [SOS], broadband ultrasound attenuation [BUA], and stiffness index [SI]) of lesbian and heterosexual women to examine the medical and lifestyle risk factors for osteoporosis in each group. This was an exploratory, community-based, cross-sectional study. Subjects were mailed food frequency, health, and physical activity questionnaires. Weight, height, and calcaneal ultrasound measurements were taken at one office visit. In communities in southern and eastern Maine, 71 lesbians and 77 heterosexual women between the ages of 30 and 50 with regular menses and in good general health were the subjects. Statistical analysis used t-tests and chi-square tests to evaluate differences between study groups. Linear regression models were used to evaluate risk factors for low calcaneal ultrasound measurements. There were no differences between the lesbian and heterosexual women in age, body mass index (BMI), exercise, calcium intake, alcohol use, or calcaneal ultrasound measurements. There was a positive association between BUA and both BMI and alcohol consumption (p < 0.01). Antidepressant use significantly reduced SOS and SI (p < 0.05). There were no differences in calcaneal ultrasound measurements between lesbian and heterosexual women. BMI was strongly and positively associated with BUA. Antidepressant use in both populations was associated with a significant reduction in calcaneal bone mass. Studies are needed to define the relationship of depression and its treatment to bone mineral density and the future risk of osteoporosis.     

Inactivation of the mitogen-activated protein kinase Mps1 from the rice blast fungus prevents penetration of host cells but allows activation of plant defense responses

The rice blast fungus, Magnaporthe grisea, generates enormous turgor pressure within a specialized cell called the appressorium to breach the surface of host plant cells. Here, we show that a mitogen-activated protein kinase, Mps1, is essential for appressorium penetration. Mps1 is 85% similar to yeast Slt2 mitogen-activated protein kinase and can rescue the thermosensitive growth of slt2 null mutants. The mps1-1Delta mutants of M. grisea have some phenotypes in common with slt2 mutants of yeast, including sensitivity to cell-wall-digesting enzymes, but display additional phenotypes, including reduced sporulation and fertility. Interestingly, mps1-1Delta mutants are completely nonpathogenic because of the inability of appressoria to penetrate plant cell surfaces, suggesting that penetration requires remodeling of the appressorium wall through an Mps1-dependent signaling pathway. Although mps1-1Delta mutants are unable to cause disease, they are able to trigger early plant-cell defense responses, including the accumulation of autofluorescent compounds and the rearrangement of the actin cytoskeleton. We conclude that MPS1 is essential for pathogen penetration; however, penetration is not required for induction of some plant defense responses.     

Head trauma: CT scan interpretation by radiology residents versus staff radiologists

The determination of diagnostic features in recorded heart sounds was investigated with Carpentier-Edwards (CE) bioprosthetic valves. Morphological features, extracted using the Choi-Williams distribution, achieved between 96 and 61% correct classification. The time-scale wavelet-transform feature set achieved 100% correct classification with native valve populations, and 87% with the CE replacements.     

Fasting plasma glucose in screening for diabetes in the Taiwanese population

OBJECTIVE: To reveal the relationship between fasting and 2-h postload plasma glucose and to examine the appropriate fasting glucose cutoff as the primary screening test for diabetes. RESEARCH DESIGN AND METHODS: We recruited 5,303 subjects from preventive services of the National Cheng Kung University Hospital. Exclusion criteria were age <20 years, pregnancy, known diabetes, and a history of recent surgery, trauma, or illness. All subjects received the 75-g oral glucose tolerance test. The relationship between fasting and 2-h glucose was examined. Sensitivities, specificities, efficiency, and predictive values were assessed at different cutoffs of fasting glucose for prediction of diabetes. RESULTS: The best fit model for the relationship between fasting and 2-h glucose was fasting glucose = 4.914-0.060 x (2-h glucose) + 0.0144 x (2-h glucose)2. From this model, the fasting glucose was 6.0 mmol/l when 2-h glucose was 11.1 mmol/l. A fasting glucose with 6.25 mmol/l gave the same diabetes prevalence as the World Health Organization 2-h glucose criterion. When 7.8 mmol/l was the fasting glucose cutoff, the sensitivity was 28.5%. Lowering the cutoff from 7.8 to 7.0 mmol/l increased the sensitivity by 11.2% and slightly reduced the specificity and positive predictive value. If the cutoffs were 6.25 and 6.0 mmol/l, the sensitivity increased and the specificity and the positive predictive value decreased accordingly. CONCLUSIONS: Our results suggest that fasting glucose as a screening criterion for diabetes could be revised downward to 7.0 mmol/l, because the slight reduction of positive predictive value was more than balanced by an apparent increase of sensitivity and insignificant change of specificity.     

Insulin activates the hepatitis B virus X gene through the activating protein-1 binding site in HepG2 cells

OBJECTIVES: To study the turnaround time (TAT) for rendering diagnoses on routine biopsy specimens, to examine pathology practice variables that influence TAT, and to assess the level of surgeons' satisfaction with biopsy TAT. DESIGN: Over a 3-month period, voluntary participants in the College of American Pathologists Q-Probes laboratory quality improvement program prospectively collected TAT data on up to 20 biopsy specimens performed on elective surgical cases, completed questionnaires profiling their institution's practice characteristics, and had surgeons complete questionnaires indicating their satisfaction with biopsy report TAT. SETTING AND PARTICIPANTS: One hundred fifty-seven private and public small hospitals located in 43 American states (n = 153), Canada (n = 1), and Australia (n = 3). MAIN OUTCOME MEASURES: The routine surgical biopsy report TATs for 2 testing intervals, each commencing when surgeons acquired the biopsy specimens. One interval concluded when pathologists signed off the biopsy diagnoses, and the other concluded when surgeons received the hard-copy reports. RESULTS: Pathologists signed off 85.9% of 5384 biopsy diagnoses by the second working day, and surgeons received 88.3% of the hard-copy reports by the fourth working day. In 90% of hospitals participating in this study, pathologists signed off half their biopsy diagnoses between the second and third postcollection days, and 90% of surgeons received half their final hard-copy reports by the fourth postcollection day. Institutional practice variables associated with fewer sign-off and/or hard-copy receipt TATs exceeding the institutional 90th percentile performance benchmarks included yearly surgical caseloads greater than 2000 cases per full-time equivalent pathologist, provision of pathology support services on site, and accreditation of the hospital by the Joint Commission on Accreditation of Healthcare Organizations and of the laboratory by the College of American Pathologists. Most (96.4%) surgeons indicated that they were satisfied with hard-copy TATs and that they believed most (98.1%) of the hard-copy TATs had no effect on the lengths of their patients' hospital stays. CONCLUSIONS: Pathologists are capable of signing off most routine biopsy diagnoses within 2 working days and delivering the final hard-copy reports to surgeons within 4 working days (both intervals measured from the time that surgeons collect biopsy specimens). Most surgeons report they are satisfied with this level of performance.     

Ectopic expression of metallothionein-III causes pancreatic acinar cell necrosis in transgenic mice

Mice express four distinct metallothioneins (MTs) that have similar metal-binding properties. MT-I and MT-II are expressed coordinately in most organs, whereas MT-III is expressed predominantly in a subset of neurons and MT-IV is expressed in certain stratified epithelia. The restricted expression of MT-III suggests that it may severe a specialized function. To test this hypothesis, transgenic mice were generated that express MT-III in the wider expression domain of MT-I. Similar transgenic lines expressing extra MT-I under the same regulation were generated as controls for the effect of over-expression of MT. Transgenic mice that express MT-III ectopically frequently die at 2-3 months of age. The pancreata of moribund mice were abnormally small and histological examination, at various ages, revealed a progressive degeneration of the acinar cells. At early stages multifocal acinar cell eosinophilia and swollen nuclei were seen and this pathology progressed to multifocal acinar cell necrosis and fibrosis. The terminal stages were characterized by a loss of the acinar compartment, leaving the islets embedded in a fibrotic remnant. Other organs of these mice were grossly and histologically normal. All organs examined from mice expressing excess MT-I were unremarkable even though expression of either MT-I or MT-III transgenes resulted in similar accumulations of zinc and copper in the pancreata. This study indicates that pancreatic acinar cells are unusually sensitive to chronic expression of MT-III. The mechanism by which MT-III disrupts pancreatic function is unclear, but the results provide further evidence that MT isoforms exhibit distinct properties and probably serve distinct biological functions.     

Susceptibility of heterozygous MnSOD gene-knockout mice to oxygen toxicity

OBJECTIVE: To study type IV collagen of skin and serum in patients with ALS. BACKGROUND: Collagen abnormalities of skin have been reported in ALS patients. However, little is known concerning type IV collagen in ALS. METHODS: We studied type IV collagen immunoreactivity of skin and measured serum levels of the 7S fragment of the N-terminal domain of type IV collagen (7S collagen) in patients with ALS and control subjects. RESULTS: The basement membrane as well as blood vessels of skin in ALS patients was weakly positive for type IV collagen as compared with those of diseased control subjects. This weak immunostaining became more pronounced as ALS progressed. The optical density for type IV collagen immunoreactivity in ALS patients was significantly lower (p < 0.001) than in diseased control subjects and was significantly decreased with duration of illness (r = -0.85, p < 0.01). Serum 7S collagen levels in patients with ALS were significantly decreased (p < 0.01) as compared with those in diseased and healthy control subjects and were negatively and significantly associated with duration of illness (r = -0.81, p < 0.001). There was an appreciable positive correlation between concentrations of serum 7S collagen and the density for type IV collagen immunoreactivity in ALS patients (r = 0.81, p < 0.02). CONCLUSIONS: These data suggest that a metabolic alteration of type IV collagen may take place in the skin of ALS patients and that the decreased levels of serum 7S collagen may reflect a decreased type IV collagen immunoreactivity of skin in patients with ALS.