Projections from the trigeminal nuclear complex to the cochlear nuclei: a retrograde and anterograde tracing study in the guinea pig

In addition to input from auditory centers, the cochlear nucleus (CN) receives inputs from nonauditory centers, including the trigeminal sensory complex. The detailed anatomy, however, and the functional implications of the nonauditory innervation of the auditory system are not fully understood. We demonstrated previously that the trigeminal ganglion projects to CN, with terminal labeling most dense in the marginal cell area and secondarily in the magnocellular area of the ventral cochlear nucleus (VCN). We continue this line of study by investigating the projection from the spinal trigeminal nucleus to CN in guinea pig. After injections of the retrograde tracers FluoroGold or biotinylated dextran amine (BDA) in VCN, labeled cells were found in the spinal trigeminal nuclei, most densely in the pars interpolaris and pars caudalis with ipsilateral dominance. The anterograde tracers Fluoro-Ruby or BDA were stereotaxically injected into the spinal trigeminal nucleus. Most labeled puncta were found in the marginal area of VCN and the fusiform cell layer of dorsal cochlear nucleus (DCN). A smaller number of labeled puncta was located in the molecular and deep layers of DCN and the magnocellular area of VCN. The trigeminal projection to CN may provide somatosensory information necessary for pursuing a sound source or for vocal production. These projections may have a role in the generation and modulation of tinnitus.     

A comparison of schizophrenic patients in different community support treatment approaches

Recent advances in the care of the chronically mentally ill in the community have resulted in a community support system approach to maintaining chronically mentally ill persons outside the hospital. Yet, very little is known of what a community support system actually is for the chronic mental patient. This paper looks at three different sorts of community support programs and compares a sample of patients within them with respect to network variables, role performance, and demographic variables. Implications regarding the use of network oriented approaches are discussed and directions for further research are explored.     

Platelet-derived growth factor in vivo: levels, activity, and rate of clearance

Platelet-derived growth factor (PDGF) is a potent mitogen for many cultured connective tissue cells. It is present in concentrated form within the platelet alpha-granules and is believed to be released during platelet degranulation at sites of vascular injury. We have used a sensitive radioreceptor assay to measure PDGF levels in whole blood serum from normal humans [17.5 +/- 3.1 (SD) ng/mL] and baboons (2.7 +/- 1.2 ng/mL). PDGF was not detected in plasma from either species. In addition, plasma was found to substantially reduce the ability of added purified PDGF to bind to the cell surface PDGF receptor on cultured cells, suggesting that plasma may contain a PDGF-binding protein that would serve to inactivate PDGF released into plasma. Calculations of PDGF concentrations in serum have been corrected for the effects of the binding protein. 125I-PDGF injected intravenously into normal baboons was cleared rapidly from the plasma (t1/2 = two minutes). The rapid clearance of 125I-PDGF did not result from iodination damage, as purified unlabeled PDGF was cleared with comparable kinetics. The rapid clearance of purified and iodinated PDGF did not result from changes in PDGF structure during purification or from removal of PDGF-associated proteins during purification, as PDGF present in freeze-thaw lysates of fresh platelets was cleared equally rapidly. We conclude that release of PDGF at sites of vascular injury would greatly increase the local concentration of PDGF and that PDGF not localized to the site of injury would be rapidly cleared from the circulation.     

Atrioventricular septal defect with a well developed primary component of the atrial septum ("septum primum")

A heart is described with an atrioventricular septal defect in which the lower part of the atrial septum ("septum primum") was well developed and in which superior and inferior bridging leaflets were attached neither to the crest of the ventricular septum nor the inferior rim of the atrial septum. Diagnostic pre-operative angiographic and echocardiographic features and the method of surgical correction are outlined.     

Juvenile psoriatic arthritis and HLA antigens.

The clinical, laboratory, and radiological features, including histocompatibility typing, of 28 patients with juvenile psoriatic arthritis are reported. The most common presentation was that of psoriasis preceding or occurring simultaneously with arthritis. The most common course of juvenile psoriatic arthritis was to start as an oligoarthritis and progress, usually to polyarthritis. No patients with juvenile psoriatic arthritis had uveitis. Overall, most patients had a good outcome (93% in functional class I and II), though 8/28 (29%) did require disease modifying drugs over a mean period of 8.8 years of follow up. The clinical features of these patients were very similar to those of a group of 158 adult patients with psoriatic arthritis with the same disease duration followed up in the clinic. Although there was an increased prevalence of B17 in both juvenile and adult psoriatic arthritis, juvenile psoriatic arthritis showed increased prevalence of A2, whereas adult psoriatic arthritis showed increased prevalence of B27, Bw39, and Cw6. This HLA association differed from that reported in other forms of juvenile arthritis.     

Pharmacodynamic-based clinical pathway for empiric antibiotic choice in patients with ventilator-associated pneumonia

Background

Because of the high frequency of multidrug resistant bacteria in our intensive care units (ICUs), we implemented a ventilator-associated pneumonia (VAP) clinical pathway based on unit-specific minimum inhibitory concentration (MIC) distributions and pharmacodynamic modeling in 3 of our ICUs.

Methods

This was a prospective, observational evaluation with a historical control group in adult patients (n = 168) who met clinical and radiologic criteria for VAP. Monte Carlo simulation was used to determine antibiotic regimens having the greatest likelihood of achieving bactericidal exposures against Pseudomonas aeruginosa. Antibiotic regimens were incorporated into an ICU-specific computerized clinical pathway as empiric agents of choice.

Results

Pharmacodynamic modeling found 3-hour infusions of cefepime 2 g every 8 hours or meropenem 2 g every 8 hours plus tobramycin and vancomycin would provide the greatest probability of empirically treating VAP in these ICUs. Infection-related mortality was reduced by 69% (8.5% vs 21.6%; P = .029), infection-related length of stay was shorter (11.7 ± 8.1 vs 26.1 ± 18.5; P < .001), and fewer superinfections were observed in patients treated on the pathway. A number of patients with nonsusceptible P aeruginosa were successfully treated with high-dose, 3-hour infusion regimens.

Conclusions

In our ICUs where multidrug resistant bacteria are common, an approach considering ICU-specific antibiotic MICs coupled with pharmacodynamic dosing strategies resulted in improved outcomes and shorter duration of treatments.     

Temporal aspects of the visuotactile congruency effect

We report an experiment designed to investigate the temporal dynamics of the visuotactile crossmodal congruency effect. Vibrotactile targets were presented randomly to the index finger (top side of a hand-held cube) or thumb (bottom side) of either hand while visual distractors were presented randomly from one of the same four possible locations. The stimulus onset asynchrony (SOA) between the vibrotactile target and the visual distractor was varied on a trial-by-trial basis. Participants made speeded discrimination responses regarding the elevation of the vibrotactile targets (i.e., upper versus lower) while trying to ignore the visual distractors. The largest crossmodal congruency effects (defined as the difference in performance between incongruent and congruent elevation distractor trials) were obtained when the visual distractor preceded the vibrotactile target by 50-100 ms, although significant effects were also reported when the distractor followed the target by as much as 100 ms. These results are discussed in terms of the conjoint influence of response competition, crossmodal perceptual interactions (i.e., the ventriloquism effect), and exogenous spatial attention on the crossmodal congruency effect. The distinct temporal signatures of each of these effects are also highlighted.     

Aspirin and Epithelial Ovarian Cancer

BACKGROUND: Epidemiological evidence suggests that chronic inflammation may influence ovarian carcinogenesis. The study objective was to examine the association between the commonly used anti-inflammatory drug aspirin and epithelial ovarian cancer. METHODS: The authors conducted a case-control study based in the New York University Women's Health Study cohort enrolled between 1985 and 1991 in New York City. After a median follow-up period of 12 years, 68 incident cases of epithelial ovarian cancer were identified. Data about regular aspirin use were collected during the 1994-1996 follow-up questionnaire. Using a case-control study design, 10 controls per case were randomly selected among study participants who matched the case by age and menopausal status. Conditional logistic regression analysis was used to study the relationships between aspirin and epithelial ovarian cancer by generating odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Relative to no aspirin use, the OR for epithelial ovarian cancer among women who reported aspirin use three or more times per week for a period of at least 6 months was 0.60 (95% CI 0.26, 1.38), after adjustment for age at menarche, parity, oral contraceptive use, and first-degree family history of breast cancer before age 50. Among recent, within the previous 5 years, users of aspirin, the adjusted OR was 0.36 (95% CI 0.11, 1.18). CONCLUSION: Although confidence intervals included unity, the observed risk estimates seem to be compatible with previous studies suggesting that regular aspirin use could be inversely associated with risk of epithelial ovarian cancer.     

Splenic necrosis in Wegener's granulomatosis

The CT appearance of asymptomatic splenic necrosis in a 11-year-old girl with Wegener's granulomatosis is presented. Sonography showed splenic inhomogeneity with patency of the splenic artery and vein. Follow-up CT showed lobulation and shrinkage of the spleen with return to a normal attenuation.