Evidence of multiple mechanisms of avermectin resistance in haemonchus contortus--comparison of selection protocols

The ginsenosides Rb1 and Rg1, the major components of ginseng saponin, inhibited not only methamphetamine-induced hyperactivity but also conditioned place preference (CPP) in mice following a single or repeated administration. Dopamine (DA) receptor supersensitivity, which developed in methamphetamine-induced CPP mice, was also inhibited by both Rb1 and Rg1. Therefore, the present results suggest that Rb1 and Rg1 may be the active components of ginseng saponin in the modulation of methamphetamine-induced dopaminergic behaviors such as hyperactivity and CPP, supporting our previous conclusion that ginseng saponin might modulate methamphetamine-induced dysfunction at both the pre- and postsynaptic DA receptors.     

Elevated nocturnal melatonin is a consequence of gonadotropin-releasing hormone deficiency in women with hypothalamic amenorrhea

Elevated nocturnal melatonin is found in women with idiopathic hypogonadotropic hypogonadism (IHH), but it is not known whether this is implicated in the etiology of their GnRH deficiency. It is unlikely that nocturnal melatonin can be implicated in the etiology of the GnRH deficiency of Kallmann's syndrome (KS), because this condition is caused by defective neuronal migration in embryonic life. We therefore measured nocturnal melatonin in women with IHH and KS to determine whether it was elevated in one or both conditions and thereby to determine whether it was implicated as cause or consequence of GnRH deficiency. Four women with IHH, 3 women with KS, and 7 individually matched (age and body size) controls were recruited. Frequent day- and nighttime samples were taken for LH pulsatility studies. All patients showed absent or diminished LH pulsatility, compared with their respective controls. Samples were also taken over 24 h for melatonin and 6-sulphatoxymelatonin (the principle metabolite of melatonin and an independent marker of its secretion). Melatonin and 6-sulphatoxymelatonin levels were elevated in 6 of 7 patients (compared with their matched controls) and were significantly elevated in the KS group (compared with their controls). The finding of elevated nocturnal melatonin (and its metabolite) in GnRH-deficient women with KS (as well as IHH) suggests that nocturnal melatonin is elevated as a consequence of GnRH deficiency, irrespective of its etiology.     

Identifying sites of replication initiation in yeast chromosomes: looking for origins in all the right places

DNA fragments that contain an active origin of replication generate bubble-shaped replication intermediates with diverging forks. We describe two methods that use two-dimensional (2-D) agarose gel electrophoresis along with DNA sequence information to identify replication origins in natural and artificial Saccharomyces cerevisiae chromosomes. The first method uses 2-D gels of overlapping DNA fragments to locate an active chromosomal replication origin within a region known to confer autonomous replication on a plasmid. A variant form of 2-D gels can be used to determine the direction of fork movement, and the second method uses this technique to find restriction fragments that are replicated by diverging forks, indicating that a bidirectional replication origin is located between the two fragments. Either of these two methods can be applied to the analysis of any genomic region for which there is DNA sequence information or an adequate restriction map.     

Pap smear screening in an urban STD clinic. Yield of screening and predictors of abnormalities

BACKGROUND: Pap smear screening studies in STD clinics have reported high rates of squamous intraepithelial lesions (SIL); however, there are limited data on levels of unsatisfactory smears of characteristics associated with cytologic abnormalities. GOAL: To assess the yield to Pap smear screening in an STD clinic and to evaluate the rates of and risk factors for atypia, low-grade SIL (LSIL), and high-grade SIL (HSIL). STUDY DESIGN: A chart review of the clinic records of women undergoing Pap smear screening between 1991 and 1994 was conducted. Results were assessed from two different screening protocols, the first using a Dacron swab to obtain the endocervical sample and the second using a cytobrush. RESULTS: Of 2034 Pap smears, 1313 (64.6%) were negative, 202 (9.9%) were unsatisfactory, 257 (12.6%) were atypical, 211 (10.4%) had LSIL, and 51 (2.5%) had HSIL. With the change to the cytobrush protocol, the rate of unsatisfactory smears decreased from 14.4% to 3% (p < 0.001), atypia increased from 10% to 16.7% (p < 0.001), and HSIL rose from 1.7% to 3.7% (p < 0.001). By multivariate analysis, atypia was associated with genital warts (odds ratio (OR) 1.53, 95% confidence interval (CI): 1.16-2.02); LSIL with younger age (p < 0.001, for trend), black race (OR 1.51, 95% CI: 1.08-2.10), genital warts (OR 1.81, 95% CI: 1.33-2.47), and an abnormal appearance of the cervix on examination (OR 2.49, 95% CI: 1.85-3.35); and HSIL with a previous abnormal Pap smear (OR 2.48, 95% CI: 1.08-2.10). Overall, abnormality rates were significantly higher in adolescents (35.5%) than older women (21.7%) (p < 0.01). CONCLUSIONS: Obtaining satisfactory Pap smears among women undergoing screening in an STD clinic is feasible and cytologic abnormalities are common. These results continue to support the need for Pap smear screening in STD clinics, but the high rates in adolescents, a group in whom the natural history of cytologic abnormalities has not been well-defined, raise questions about the need to develop age-appropriate screening and management strategies.     

Murine IgG1 complexes trigger immune effector functions predominantly via Fc gamma RIII (CD16)

Previously, we have demonstrated that phagocytosis of IgG1-coated particles by macrophages in vitro is impaired by deletion of Fc gamma RIII in mice, suggesting that IgG1 may interact preferentially with Fc gamma RIII. In the present study, the biologic relevance of this observation was addressed by triggering various effector functions of the immune system in Fc gamma RIII(-/-) mice, using panels of mAbs of different IgG subclasses. Both binding and phagocytosis of IgG1-coated sheep or human erythrocytes by Fc gamma RIII(-/-) macrophages in vitro were strongly impaired, indicating that the impaired ingestion of complexed IgG1 by Fc gamma RIII(-/-) macrophages is due to a defect in binding. An in vivo consequence of the defective phagocytosis was observed by resistance of Fc gamma RIII-deficient mice to experimental autoimmune hemolytic anemia, as shown by a lack of IgG1-mediated erythrophagocytosis in vivo by liver macrophages. Furthermore, trapping of soluble IgG1-containing immune complexes by follicular dendritic cells in mesenteric lymph nodes from Fc gamma RIII(-/-) mice was abolished. Whole blood from Fc gamma RIII(-/-) mice was unable to induce lysis of tumor cells in the presence of IgG1 antitumor Abs. Finally, IgG1 mAbs proved unable to mount a passive cutaneous anaphylaxis in Fc gamma RIII(-/-) mice. Together, these results demonstrate that IgG1 complexes, either in particulate or in soluble form, trigger in vitro and in vivo immune effector functions in mice predominantly via Fc gamma RIII.     

Consequences of electroencephalographic-suppressive doses of propofol in conjunction with deep hypothermic circulatory arrest

BACKGROUND: Some patients who undergo cerebral aneurysm surgery require cardiopulmonary bypass and deep hypothermic circulatory arrest. During bypass, these patients often are given large doses of a supplemental anesthetic agent in the hope that additional cerebral protection will be provided. Pharmacologic brain protection, however, has been associated with undesirable side effects. These side effects were evaluated in patients who received large doses of propofol. METHODS: Thirteen neurosurgical patients underwent cardiopulmonary bypass and deep hypothermic circulatory arrest to facilitate clip application to a giant or otherwise high-risk cerebral aneurysm. Electroencephalographic burst suppression was established before bypass with an infusion of propofol, and the infusion was continued until the end of surgery. Hemodynamic and echocardiographic measurements were made before and during the prebypass propofol infusion and again after bypass. Emergence time also was determined. RESULTS: Prebypass propofol at 243 +/- 57 micrograms.kg-1.min-1 decreased vascular resistance from 34 +/- 8 to 27 +/- 8 units without changing heart rate, arterial or filling pressures, cardiac index, stroke volume, or ejection fraction. Propofol blood concentration was 8 +/- 2 micrograms/ml. Myocardial wall motion appeared hyperdynamic at the end of cardiopulmonary bypass, and all patients were weaned therefrom without inotropic support. After bypass, vascular resistance decreased further, and cardiovascular performance was improved compared to baseline values. Nine of the 13 patients emerged from anesthesia and were able to follow commands at 3.1 +/- 1.4 h. Three others had strokes and a fourth had cerebral swelling. CONCLUSIONS: Propofol infused at a rate sufficient to suppress the electroencephalogram does not depress the heart or excessively prolong emergence from anesthesia after cardiopulmonary bypass and deep hypothermic circulatory arrest.     

Guidelines for the treatment of cytomegalovirus diseases in patients with AIDS in the era of potent antiretroviral therapy: recommendations of an international panel. International AIDS Society-USA

OBJECTIVE: To provide recommendations for the treatment of acquired immunodeficiency syndrome-related cytomegalovirus (CMV) end-organ diseases, including retinitis, colitis, pneumonitis, and neurologic diseases. PARTICIPANTS: A 17-member panel of physicians with expertise in clinical and virological research and inpatient care in the field of CMV diseases. EVIDENCE: Available clinical and virological study results. Recommendations are rated according to the quality and strength of available evidence. Recommendations were limited to the treatment of CMV diseases; prophylaxis recommendations are not included. PROCESS: The panel was convened in February 1997 and met regularly through November 1997. Subgroups of the panel summarized and presented available information on specific topics to the full panel; recommendations and ratings were determined by group consensus. CONCLUSIONS: Although the epidemiological features of CMV diseases are changing in the setting of potent, combination antiretroviral therapy, continued attention must be paid to CMV diseases in patients infected with the human immunodeficiency virus to prevent irreversible endorgan dysfunction. The initial and maintenance treatment of CMV retinitis must be individualized based on the characteristics of the lesions, including location and extent, specific patient factors, and characteristics of available therapies among others. Management of relapse or refractory retinitis must be likewise individualized. Ophthalmologic screening for patients at high risk for retinitis or who have a prior diagnosis of extraretinal disease is recommended. Recommendations for gastrointestinal, pulmonary, and neurologic manifestations are included.     

Rapid diagnosis of tuberculous meningitis by polymerase chain reaction assay of cerebrospinal fluid

A polymerase chain reaction (PCR) method for the rapid diagnosis of tuberculous meningitis (TBM) was used to study prospectively 47 cerebrospinal fluid (CSF) samples from 45 patients. Twenty CSF samples were from patients with clinically suspected TBM and another 27 samples came from patients without clinically suspected TBM. Mycobacterial DNA was detected in 15 CSF samples (14 from patients with clinically suspected TBM and 1 from a patient not suspected of having TBM). Of the PCR-positive samples, 4 were also positive for mycobacterial culture. However, 32 PCR-negative samples were all culture-negative. All samples were negative for the acid-fast bacillus by direct smear. The single PCR-positive patient in the clinically unsuspected TBM group was initially diagnosed as suffering from aseptic meningitis on the basis of his clinical features. The mycobacterial culture of his CSF specimen was also positive and a revised diagnosis of an aseptic type of TBM was made. The estimations of specificity and sensitivity in this study were 100% and 70% respectively. The results showed that using a PCR to detect mycobacterial DNA in CSF for the early diagnosis of TBM is not only a rapid but also an accurate method.     

Identification of interleukin-2 receptor-associated tyrosine kinase p116 as novel leukocyte-specific Janus kinase

Janus tyrosine kinase (JAK) has recently been linked to signal transduction by cytokine receptors of the hematopoietin family. We have recently described a 116-kDa tyrosine kinase (p116) present in interleukin-2 (IL-2) receptor complexes in human YT cells that showed functional characteristics of a JAK kinase. These included receptor association, rapid and transient tyrosine phosphorylation kinetics in response to ligand, and in vitro autophosphorylating tyrosine kinase activity (Kirken, R. A., Rui, H., Evans, G. A., and Farrar, W. L. (1993) J. Biol. Chem. 268, 22765-22770). Here we extend these observations by demonstrating structural homologies between IL-2-modulated p116 and prolactin-modulated JAK2 in the rat T cell line Nb2. These include similar net charge as determined by nonequilibrium pH gradient electrofocusing and related primary structure based upon phosphopeptide mapping of V8 protease-digested hyperphosphorylated proteins. This putative JAK kinase underwent marked tyrosine phosphorylation in response to IL-2, IL-4, and IL-7, lymphoid growth factors that use the common IL-2 receptor gamma-chain, but not in response to prolactin. Furthermore, polyclonal antisera to JAK1, JAK2, or tyrosine kinase 2 did not recognize either rat or human p116. However, we identified the IL-2-modulated p116 as the recently cloned novel leukocyte Janus kinase, L-JAK, using an antiserum to a peptide corresponding to the COOH terminus of human L-JAK.