Pituitary tumorigenesis and hPit-1 cells

Despite decades of clinical data verifying the success of therapeutic approaches to human pituitary tumors, a significant number of tumors progress and can be life-threatening. The development of better therapeutic strategies for pituitary tumors is complicated by the relative scarcity of human pituitary material for basic experimentation. Human pituitary tissue was used to derive cell cultures, and a cell line, hPIT-1. Molecular and functional analyses were used to further characterize the cells as human pituitary explants in vitro. Functional analyses of the cell cultures indicated that the cells were tumorigenic and of human folliculostellate origin. hPit-1 cells revealed numerous abnormalities of ploidy. Molecular analyses indicated the absence of expression of the following pituitary hormones or hormone subunits by this culture: growth hormone, prolactin, ACTH, FSHbeta, LHbeta, THbeta, and p-glycoprotein. By contrast, the cells expressed uniformly high levels of human follistatin mRNA. Finally, the cells are moderately tumorigenic in immune-deficient mice. Although the precise molecular genetic mechanisms for tumorigenesis in the established cell culture are unknown, the cells serve as a future resource in the study of pituitary tumor initiation, progression, and response to therapy.

Effect of chronic ethanol consumption on protective T-helper 1 and T-helper 2 immune responses against the parasites Leishmania major and Strongyloides stercoralis in mice

BACKGROUND

Chronic alcohol consumption has been associated with significant increases in the prevalence of infectious diseases, and it has been suggested that these increases are caused by a direct effect of ethanol on the immune response. The objective of this study was to determine whether chronic ethanol consumption would affect the development of protective immunity to Leishmania major, which is controlled by the T-helper 1 (Th1) subset of CD4 cells, and Strongyloides stercoralis, which is controlled by the Th2 subset.

METHODS

Mice were fed ethanol-containing liquid diet (25% ethanol-derived calories), liquid isocaloric diet without ethanol, or solid chow and then exposed to either of the two parasites. The ability of the mice chronically consuming alcohol to eliminate the infections was determined, as were the levels of parasite-specific humoral and cellular immune responses.

RESULTS

Mice chronically consuming alcohol were capable of eliminating both of these infections in a manner identical to the control mice. In addition, splenocytes from mice chronically consuming alcohol infected with L. major produced nitric oxide at the same levels as in control mice. Antibody responses were altered in a manner suggesting an increase in Th2 immunity and a decrease in Th1 immunity in the mice chronically consuming alcohol. In mice chronically consuming alcohol that were infected with S. stercoralis, eosinophils migrated to the parasite's microenvironment, and antibodies were produced at levels equivalent to those seen in control mice.

CONCLUSIONS

Mice maintained on an ethanol-containing liquid diet had some alteration in their ability to produce Th1 and Th2 immune responses yet were capable of generating unimpaired protective Th1 and Th2 responses.

Development of a recombinant antigen vaccine against infection with the filarial worm Onchocerca volvulus

Efforts to control Onchocerca volvulus, the etiologic agent of river blindness, have been limited to vector control and drug treatment to eliminate microfilariae, with no means available to prevent infection. The goal of this study was to develop a vaccine against this infection using recombinant antigens that are expressed in the early larval stages of the parasite. Five recombinant antigens, Ov7, Ov64, OvB8, Ov9M, and Ov73k, were identified by screening adult and larval cDNA libraries with antibodies from immune humans, chimpanzees, or rabbits. When mice were immunized with the five individual recombinant antigens, statistically significant reductions in parasite survival were induced in mice immunized with Ov7, OvB8, or Ov64, when administered in alum but not when injected in Freund's complete adjuvant (FCA). Live larvae recovered from control and immunized mice were analyzed to determine their developmental stages. A decrease in the percentage of larvae molting from the third stage to the fourth stage was observed with mice immunized with Ov7, Ov64, or OvB8 in alum but not with mice immunized with Ov9 and Ov73k or with mice immunized with any of the five antigens in FCA. Mice immunized with a cocktail of the three protective antigens developed protective immunity equal to that seen with mice immunized with individual antigens. This study has identified, for the first time, three recombinant antigens capable of inducing protective immunity to O. volvulus. Furthermore, since the antigens functioned with alum as the adjuvant, this vaccine could potentially be used clinically to prevent river blindness in humans.

Characteristics of physicians presenting for assessment at a behavioral health center

Physician health and impairment have been of considerable interest in recent years. This study contributes detailed clinical data to the existing body of knowledge, by drawing from a sample of physicians assessed at a behavioral health center over a two year time frame. Demographic, referral, and clinical data were gathered using a systematic medical record review procedure, based on 108 physicians who were evaluated within an intensive multidisciplinary assessment program. The majority suffered from active substance use disorders (52.8%), with other psychiatric disorders (29.6%), and substance use disorders in remission (17.6%) the other largest categories. Of those with an active substance use disorder, primary drugs of choice were alcohol and prescription opiates. Over half had comorbid psychiatric disorders (Axis I, II, or both). Significant relationship, employment, and emotional problems were found in all three groups. The significant increase in presentation and/or detection of psychiatric and behavioral problems, both comorbid with and not substance use related, confirms the need for a revision and expansion of views about physicians' behavioral health concerns.

Lens injury stimulates axon regeneration in the mature rat optic nerve

In mature mammals, retinal ganglion cells (RGCs) are unable to regenerate their axons after optic nerve injury, and they soon undergo apoptotic cell death. However, a small puncture wound to the lens enhances RGC survival and enables these cells to regenerate their axons into the normally inhibitory environment of the optic nerve. Even when the optic nerve is intact, lens injury stimulates macrophage infiltration into the eye, Müller cell activation, and increased GAP-43 expression in ganglion cells across the entire retina. In contrast, axotomy, either alone or combined with intraocular injections that do not infringe on the lens, causes only a minimal change in GAP-43 expression in RGCs and a minimal activation of the other cell types. Combining nerve injury with lens puncture leads to an eightfold increase in RGC survival and a 100-fold increase in the number of axons regenerating beyond the crush site. Macrophage activation appears to play a key role, because intraocular injections of Zymosan, a yeast cell wall preparation, stimulated monocytes in the absence of lens injury and induced RGCs to regenerate their axons into the distal optic nerve.

Formation of molecular gas in the tidal debris of violent galaxy-galaxy interactions

In many gravitational interactions between galaxies, gas and stars that have been torn from the precursor galaxies can collect in tidal 'tails'. Star formation begins anew in some of these regions, producing tidal dwarf galaxies. Observations of these new galaxies provides insight into processes relevant to galaxy formation more generally, because the timescale of the interaction is well defined. But tracking the star formation process has hitherto been difficult because the tidal dwarf galaxies with young stars showed no evidence of the molecular gas out of which those young stars formed. Here we report the discovery of molecular hydrogen (traced by carbon monoxide emission) in two tidal dwarf galaxies. In both cases, the concentration of molecular gas peaks at the same location as the maximum in atomic-hydrogen density, unlike the situation in most gas-rich galaxies. We infer from this that the molecular gas formed from the atomic hydrogen, rather than being torn in molecular form from the interacting galaxies. Star formation in the tidal dwarf galaxies therefore appears to mimic the process in normal spiral galaxies like our own.

Evaluation of resins for on-bead screening: a study of papain and chymotrypsin specificity using PEGA-bound combinatorial peptide libraries

TentaGel, ArgoGel and PEGA resins were evaluated for on-bead biological screening, using a fluorescently-labelled peptide attached to each and assayed for papain activity. Peptide attached to PEGA was cleaved in near quantitative yield at the expected sites, whilst an identical sequence on TentaGel and ArgoGel beads was hydrolysed in very low yields and nonspecifically on ArgoGel. The compatibility of PEGA with enzymes was further demonstrated by the determination of subsite specificities of papain and chymotrypsin using PEGA-bound peptide libraries, which proved to be similar to those observed in free solution.

Female physicians and substance abuse. Comparisons with male physicians presenting for assessment

As with women in general, the vicissitudes of the female physician who suffers from a substance use disorder have been understudied, and such persons remain underrepresented in treatment. The purpose of the present study is to describe the similarities and differences between female and male physicians presenting for assessment; 108 physicians in total were included in the study, 10 of whom were female. Demographically, we found that the female physicians were more likely to be single and younger than their male counterparts. On clinical indices, females showed less impairment on legal and medical functioning, and better capability in sustaining abstinence and eliminating environmental cues to relapse. Of the women with substance use disorders, higher rates of comorbidity were found than with males. Although there were no significant differences in overall severity, males were more likely to be recommended to more intensive levels of care for either substance use or psychiatric disorders. The female physicians were recommended to a level of care of a lower intensity, but more often to a treatment with a dual-diagnosis focus. These findings are discussed in terms of the vulnerabilities of the female physician, barriers to treatment, tailoring treatment to female needs, and opportunities for prevention and further research.

Differential therapeutics and the impaired physician: patient-treatment matching by specificity and intensity

The objective of this study was to determine the nature and degree of patient to treatment matching for a sample of physicians based on differential problem type and severity. Methods included a single assessment of variables using retrospective chart review. Subjects included 108 physicians (98 men and 10 women), who were sampled consecutively from assessments performed over a 2-year period. They represented a variety of specialties, and most were third-party referred, predominantly by state medical societies. Main outcome measures included demographic information, DSM-IV multiaxial diagnoses, the Severity of Substance-Related Disorder scale, and the type and intensity of recommended treatment. It was found that the physicians presented with a variety of conditions that were clustered into three categories: active substance use disorders (52.8%), substance use disorders in remission (17.6%), and psychiatric/behavioral problems (29.6%). An analysis of the appropriateness of matching types of treatment to these problem categories appeared to support a differential assignment process. A range in severity was also found within problem categories and was subsequently tested for correspondence with the range in intensity of recommended treatment. It was found that severity correlated strongly with recommended treatment intensity for all groups. In addition, multiple regression analyses showed that two factors, ability to sustain abstinence and emotional disturbance, were predictive of treatment intensity for the two substance use disorder subgroups (64% of variance accounted for). In the psychiatric/behavioral problem subgroup, such analysis demonstrated that the severity of difficulties with one's significant other was predictive of treatment intensity (89% of variance accounted for).

Measuring inhibitory control in children

The Stop Signal Task is a measure of inhibitory control in which subjects must press a button in response to a stimulus. On certain trials, the subject receives a second stimulus (the Stop Signal) after the primary stimulus and must withhold his/her response during those trials. The onset of the Stop Signal is varied, sometimes coming immediately after the primary stimulus (inhibition is easy); at other times, the Stop Signal arrives quite late, making inhibition difficult. Results from the Stop Signal Task were obtained from children with attention-deficit/hyperactivity disorder (ADHD) and from controls; children with ADHD had significantly more difficulty inhibiting their responses than did controls. In a second study, results from the Stop Signal Task were obtained from a large sample of both behaviorally disturbed and community children; variables from the Stop Signal Task correlated well with both laboratory observations and teacher ratings of inattention and hyperactivity.

Clinical dementia rating training and reliability in multicenter studies: the Alzheimer's Disease Cooperative Study experience

Global ratings of dementia severity are used increasingly in clinical trials of antidementia compounds. Such ratings are clinically relevant, but their reliability in multicenter settings has not been determined. To evaluate the reliability of one global scale, the Clinical Dementia Rating (CDR), 82 investigators of the multicenter Alzheimer's Disease Cooperative Study participated in a training and reliability protocol using videotaped assessments of subjects in various stages of Alzheimer's disease. Following training, overall agreement of the investigators with "gold standard" CDR scores was 83%. These results indicate that the training protocol is useful for establishing good levels of agreement in staging dementia severity and that the CDR can be standardized as a clinical global scale for multicenter studies of Alzheimer's disease.