Predator odor produces anxiety-like behavioral phenotype in planarians that is counteracted by fluoxetine

Avoidant behavior is a characteristic feature post-traumatic stress disorder (PTSD) and is modeled in mammals with predator odor. Light avoidance is a hallmark behavioral reaction in planarians. We hypothesized that planarians exposed to frog extract would display enhanced light avoidance that is prevented by fluoxetine. Enhanced light avoidance (i.e., less time spent in light compartment of a dish split into light and dark sides) after a 30-min frog extract exposure (0.0001-0.01%) manifested 15 min post-exposure, persisted for at least 24 h, and was counteracted by fluoxetine (10 μM). These results suggest conservation of an anxiety-like behavioral phenotype.

Isoniazid preventive therapy in HIV-infected children on antiretroviral therapy: a pilot study

SETTING

Tuberculosis (TB) is a common cause of mortality and morbidity in children infected with the human immunodeficiency virus (HIV). Data on isoniazid preventive therapy (IPT) efficacy in HIV-infected children receiving antiretroviral therapy (ART) are inconclusive.

OBJECTIVE

To assess the efficacy, tolerability and safety of isoniazid (INH) in HIV-infected children on ART.

DESIGN

A pilot randomised controlled study of INH was undertaken in HIV-infected children on ART. The primary outcome measure was TB disease or death.

RESULTS

A total of 167 children were randomised to receive INH (n = 85) or placebo (n = 82), and followed for a median of 34 months (interquartile range [IQR] 24-52). The median age was 35 months (IQR 15-65). There was one death in a child on INH and none in the placebo group. Eleven (6.6%) cases of TB occurred, 4 (5%) in the INH and 7 (9%) in the placebo group. Among the TB cases, 5 were culture confirmed-2 in the INH group and 3 in the placebo group, all susceptible to INH. Severe adverse events occurred rarely (n = 6; 2%).

CONCLUSION

IPT is safe and well tolerated in HIV-infected children on concomitant ART. This study supports the need for a larger study to assess efficacy in HIV-infected children living in TB-endemic areas.

Bacteriologically confirmed tuberculosis in HIV-infected infants: disease spectrum and survival

BACKGROUND

The human immunodeficiency virus (HIV) has resulted in epidemiological shifts with an emergence of tuberculosis (TB) amongst HIV-infected women and infants. There are limited data on the TB disease spectrum and outcome amongst HIV-infected infants.

OBJECTIVES

We describe the clinical characteristics, treatment and survival of HIV-infected infants with culture-confirmed TB.

METHODS

This retrospective hospital-based study from Cape Town, South Africa, used routine laboratory-based surveillance among infants diagnosed with culture-confirmed TB from 1 January 2004 to 31 December 2006. Folder and chest radiographic review were completed and vitality status established. TB was classified as pulmonary, extra-pulmonary or disseminated disease.

RESULTS

Of 52 infants, 37 (71.1%) had pulmonary, 2 (3.9%) extra-pulmonary only, 7 (13.5%) pulmonary and extra-pulmonary and 6 (11.5%) disseminated TB. Forty-six (88.5%) were started anti-tuberculosis therapy; 37 (71.2%) received antiretroviral therapy (ART) and 17 (32.7%) died, 10 (19.2%) of whom never started ART. HIV stage 4 disease was associated with death. TB treatment outcome was poorly documented.

CONCLUSIONS

TB is associated with advanced HIV disease and high mortality in HIV-infected infants. Missed opportunities for initiation of ART were frequent. Although the effects of young age, TB disease spectrum and HIV co-infection are difficult to distinguish, our findings support the initiation of early ART in HIV-infected infants with TB.

Predicting protected sexual behaviour using the Information-Motivation-Behaviour skills model among adolescent substance abusers in court-ordered treatment

The Information-Motivation-Behavioural skills model (Fisher & Fisher, 1992) was used to predict condom use among adolescents residing in a court-ordered inpatient substance abuse treatment programme (N = 271; 181 male and 90 female, primarily of minority ethnicity). In a predictive structural equation model, demographic variables, HIV transmission knowledge, and motivational variables of pro-condom norms and attitudes, and perceived susceptibility predicted condom use skills and condom use self-efficacy. Along with the other variables in the model, condom skills and condom self-efficacy were hypothesized to predict condom use over a three-month period. It was found that condom skills were predicted by greater age, pro-condom attitudes and greater perceived susceptibility. Condom self-efficacy was predicted by gender, pro-condom norms and condom attitudes. Condom use was significantly predicted by pro-condom norms and stronger condom self-efficacy. Both condom skills and knowledge did not significantly predict condom use. Significant demographic predictors of condom use included greater age and gender. Results suggest that changing personal attitudes about condoms and reinforcing the power of pro-condom beliefs among significant others will encourage condom use among adolescents who are at high risk for HIV and other STDs.

High incidence of tuberculosis among HIV-infected infants: evidence from a South African population-based study highlights the need for improved tuberculosis control strategies

BACKGROUND

There are limited population-based estimates of tuberculosis incidence among human immunodeficiency virus (HIV)-infected and HIV-uninfected infants aged < or =12 months. We aimed to estimate the population-based incidence of culture-confirmed tuberculosis among HIV-infected and HIV-uninfected infants in the Western Cape Province, South Africa.

METHODS

The incidences of pulmonary, extrapulmonary, and disseminated tuberculosis were estimated over a 3-year period (2004-2006) with use of prospective representative hospital surveillance data of the annual number of culture-confirmed tuberculosis cases among infants. The total number of HIV-infected and HIV-uninfected infants was calculated using population-based estimates of the total number of live infants and the annual maternal HIV prevalence and vertical HIV transmission rates.

RESULTS

There were 245 infants with culture-confirmed tuberculosis. The overall incidences of tuberculosis were 1596 cases per 100,000 population among HIV-infected infants (95% confidence interval [CI], 1151-2132 cases per 100,000 population) and 65.9 cases per 100,000 population among HIV-uninfected infants (95% CI, 56-75 cases per 100,000 population). The relative risk of culture-confirmed tuberculosis among HIV-infected infants was 24.2 (95% CI, 17-34). The incidences of disseminated tuberculosis were 240.9 cases per 100,000 population (95% CI, 89-433 cases per 100,000 population) among HIV-infected infants and 14.1 cases per 100,000 population (95% CI, 10-18 cases per 100,000 population) among HIV-uninfected infants (relative risk, 17.1; 95% CI, 6-34).

CONCLUSIONS

This study indicates the magnitude of the tuberculosis disease burden among HIV-infected infants and provides population-based comparative incidence rates of tuberculosis among HIV-infected infants. This high risk of tuberculosis among HIV-infected infants is of great concern and may be attributable to an increased risk of tuberculosis exposure, increased immune-mediated tuberculosis susceptibility, and/or possible limited protective effect of bacille Calmette-Guérin vaccination. Improved tuberculosis control strategies, including maternal tuberculosis screening, contact tracing of tuberculosis-exposed infants coupled with preventive chemotherapy, and effective vaccine strategies, are needed for infants in settings where HIV infection and tuberculosis are highly endemic.

Elevated phosphorylated mammalian target of rapamycin (p-mtor) expression in human neoplasms

10571

Background: Mammalian target of rapamycin (mTOR) regulates several cell functions critical to tumorigenesis including proliferation, growth, mobility and survival. mTOR expression and dysregulation have been reported carcinomas of breast, head & neck, liver and kidney, but have not yet been studied in non small cell lung cancers (NSCLC), colorectal adenocarcinomas (CRC), nor brain tumors including gemistocytic astrocytomas (GA) and glioblastomas (GBM). Methods: Formalin-fixed paraffin-embedded tissue sections from 121 NSCLC [45 squamous cell carcinomas (SCC), 45 pure adenocarcinomas (AC), and 31 bronchioloalveolar carcinomas (BAC) including both pure BAC and adenocarcinomas with BAC features], 108 CRC, 8 GA and 24 GBM were immunostained by an automated method (Ventana Medical Systems, Tucson, AZ) using monoclonal rabbit anti-human p-mTOR antibody (Cell Signaling, Danvers, MA). Immunohistochemical assessment included intensity and percentage of positive cells in both benign and carcinomatous elements. Results were correlated with morphologic and prognostic variables in NSCLC and CRC and GBM. Results: Elevated p-mTOR expression was noted in 33% SCCs, 64% ACs, and 65% BAC, 78% CRC, 75% GA and 96% GBM. For NSCLC, increased expression of p-mTOR correlated with histologic subtype (p=0.004). Within SCC greater than 3 cm in size, only 20% had an increase in p-mTOR, while 53% of SCC ≤ 3 cm showed an increase in p-mTOR expression (p=0.03). 100% high grade vs. 43% low grade (p=0.05) and 100% advanced stage (p=0.037) vs. 54% low stage BAC showed an increase in p-mTOR. Consistently, 100% BACs with positive lymph node status vs. 54% node negative BACs showed an increased level of p-mTOR (p=0.037). For CRC, p-mTOR over-expression correlated with high tumor grade (80% Grade 3 vs 50% Grade 1 p=0.042). Majority of GA (6/8) and nearly all GBM (23/24) were positive for p-mTOR (p=0.135). Conclusions: Activated mTOR protein, defined by phosphorylation of mTOR at Serine-2448 (p-mTOR), is increased in NSCLC, CRC and both GA and GBM. These findings suggest a potential role for mTOR dysregulation in lung, colon and brain tumorigenesis and support the currently ongoing clinical trials investigating the therapeutic relevance of rapamycin analogs in the treatment of these tumors.

No significant financial relationships to disclose.

Nanometal Surface Energy Transfer in Optical Rulers, Breaking the FRET Barrier

Optical-based distance measurements are essential for tracking biomolecular conformational changes, drug discovery, and cell biology. Traditional Forster resonance energy transfer (FRET) is efficient for separation distances up to 100 A. We report the first successful application of a dipole-surface type energy transfer from a molecular dipole to a nanometal surface that more than doubles the traditional Forster range (220 A) and follows a 1/R(4) distance dependence. We appended a 1.4 nm Au cluster to the 5' end of one DNA strand as the energy acceptor and a fluorescein (FAM) to the 5' end of the complementary strand as the energy donor. Analysis of the energy transfer on DNA lengths (15, 20, 30, 60bp), complemented by protein-induced DNA bending, provides the basis for fully mapping the extent of this dipole surface type mechanism over its entire usable range (50-250 A). Further, protein function is fully compatible with these nanometal-DNA constructs. Significantly extending the range of optical based methods in molecular rulers is an important leap forward for biophysics.

Substance-abusing adolescents at varying levels of HIV risk: psychosocial characteristics, drug use, and sexual behavior

PURPOSE

To evaluate the relationship of various psychosocial factors on HIV sexual risk behavior in a sample of 169 "inner city" male and female adolescents mandated into in court-ordered substance abuse treatment.

METHOD

The Millon Adolescent Clinical Inventory (MACI) and measures of sexual behavior, condom attitudes and skills, HIV knowledge, and substance abuse were administered. Data were evaluated according to five HIV risk groups: abstinent (n = 37); monogamous and practicing only protected sex (n = 19); monogamous and practicing unprotected sex (n = 45); multiple partners and practicing only protected sex (n = 11); and multiple partners and having only unprotected sex (n = 57).

RESULTS

Significant main effects were found for impulsive propensity, submissiveness, marijuana and alcohol use, condom attitudes, and intentions to engage in safer sex. Protective behavior was directly associated with submissiveness and inversely associated with impulsive personality profiles, with increased marijuana use emerging as a significant predictive factor in the choice for sexual activity vs. abstinence. More alcohol use was predictive of choosing multiple partners vs. monogamy.

IMPLICATIONS

Factoring risk variation into the design of HIV psychosocial research may enhance the tailoring of effective prevention strategies.

Inhaled nitric oxide improves survival in the rat model of high-altitude pulmonary edema

OBJECTIVES

High-altitude pulmonary edema (HAPE) afflicts certain individuals after a rapid gain in elevation. Those susceptible demonstrate an exaggerated hypoxic pulmonary vasoconstrictive response. This causes pulmonary hypertension, which may disrupt vascular integrity. This experiment was designed to test whether inhaled nitric oxide would affect development of HAPE in a rat model.

METHODS

Subjects were exposed in a hypobaric chamber to a simulated altitude of 6200 m (barometric pressure = 380 mm Hg, fraction of inspired oxygen = 0.19) for 24 hours. Control animals (n = 48) spontaneously breathed a mixture of 90% room air and 10% nitrogen, whereas the nitric oxide group (n = 48) received a similar mixture containing 83 ppm nitric oxide. Postmortem examination of lungs was performed for light microscopy, total hemoglobin, and gravimetric estimates of water content.

RESULTS

Mortality was 39.5% (n = 19) in control animals and 6.2% (n = 3) in the nitric oxide group (P < .001). Both groups significantly increased their lung weight-body weight ratio. Percentage of lung water was similar in both groups despite increases in lung weight, which is consistent with the protein-rich edema characteristic of HAPE. Light microscopic examination of survivors' lungs in both groups revealed scattered alveolar hemorrhage. No significant cellular inflammatory response was present.

CONCLUSIONS

We conclude that inhaled nitric oxide improves survival in the rat model of HAPE.

The impact of training in problem-based interviewing on the detection and management of psychological problems presenting in primary care

BACKGROUND

The vast majority of mental health problems present to primary care teams. However, rates of under-diagnosis remain worryingly high. This study explores a GP-centred approach to these issues.

AIM

To examine the impact of training in problem-based interviewing (BPI) on the detection and management of psychological problems in primary care.

METHOD

The detection and management of psychological problems by 10 general practitioners (GPs) who had received PBI training 12 months earlier was compared with that of 10 control GPs matched for age, sex, clinical experience, and practice setting; and had originally applied for, but had not been able to attend, BPI training. Consecutive attendees at one randomly selected surgery undertaken by each GP were invited to participate in the study. Two hundred and eighty patients living in Newcastle upon Tyne met inclusion criteria and gave informed consent. The presence or absence of psychological problems was assessed using patient self-ratings on the 28-item version of the General Health Questionnaire (GHQ) and blind independent observer ratings of the brief Present State Examination (PSE). Patient satisfaction with interviews was rated using the Medical Interview Satisfaction Scale (MISS). After each consultation, the GPs (blind to subjective and observer ratings) recorded their assessment and management of the patients' problems on a Practice Activity Card (PAC).

RESULTS

In comparison with control GPs, index GPs demonstrated significantly greater sensitivity in the detection of psychological problems in the GHQ-PAC ratings. The absolute decrease in misdiagnosis of GHQ cases was 9% and of PSE cases was 15%. Patients meeting GHQ criteria for caseness were more likely to be prescribed psychotropic medication by an index GP than compared with a control GP. Length of interview did not differ between the groups and mean scores on the MISS suggested that patients attending PBI-trained GPs, compared with control GPs, were as satisfied or slightly more satisfied with their consultation.

CONCLUSION

In comparison with control GPs, PBI-trained GPs were better at recognizing and managing psychological disorders. The potential benefits of BPI training are discussed in light of other attempts to improve mental health skills in primary care.

Novel CD44 messenger RNA isoforms in human thyroid and breast tissues feature unusual sequence rearrangements

CD44 is a family of cell surface proteins implicated in adhesion interactions and tumor metastasis. Multiple CD44 mRNA isoforms arise from alternative splicing of variant exons (termed v1-v10). We recently discovered a novel CD44 mRNA isoform in human papillary thyroid cancers featuring a junction between subsegments of exons 4 and 13 (v8). The sequence ACAG was repeated at both the donor and acceptor sites in the genomic DNA (G. Ermak et al., Cancer Res., 56: 1037-1042, 1996). We used reverse transcription-PCR to characterize expression of this isoform in a panel of thyroid lesions. In addition, we assayed three cryopreserved human breast cancers and two samples of normal breast tissue (from female subjects who had undergone cosmetic mammoplasty) to determine whether a similar isoform is present in breast carcinomas. Levels of the novel isoform were up-regulated in 88% of the goiters, adenomas, and papillary cancers, but were undetectable in cases of thyroiditis and absent or low-level in four samples of normal thyroid tissue. The three breast cancers each yielded a 546-bp PCR product that was not detected in normal breast tissue. The PCR product from one of the breast cancers was cloned, and sequence analysis revealed a novel mRNA isoform featuring a junction between exon 3 and an internal site within exon 13 (v8). The sequence GCTTCAG was repeated at both the donor and acceptor sites in the genomic DNA. These results show that human thyroid and breast tissues contain novel CD44 mRNA isoforms featuring unusual rearrangements at repeated sequences. Further studies are warranted to determine whether the expression of this class of isoforms correlates with growth status.

Restricted patterns of CD44 variant exon expression in human papillary thyroid carcinoma

CD44 is a polymorphic family of cell surface proteoglycans and glycoproteins implicated in cell-cell and cell-matrix adhesion interactions, cell migration, and tumor metastasis. CD44 exists as a standard form and as multiple isoforms arising from alternative splicing of variant exons (termed v1-v10) encoding parts of the extracellular domain. We demonstrated previously that papillary thyroid carcinomas exhibit aberrant patterns of alternative CD44 mRNA splicing (G. Ermak et al., Cancer Res., 55: 4594-4598, 1995). In the present report, we use reverse transcription-PCR using a new high-performance polymerase formulation (Ex Taq; TaKaRa Shuzo Co., Ltd., Otsu, Japan) , followed by Southern hybridization, and demonstrate that alternative exon usage in papillary thyroid carcinomas is restricted primarily to exons v6, v7, v8, v9, and v10, with weak expression of v3. Expression of v8 is tightly linked to v9 and closely related to v10 expression. Also, v6 and v7 expression are closely related. Papillary thyroid cancers exhibit a marked increase in specific mRNA species containing combinations of exons v6 to v10. Several isoforms found in papillary cancers are not detectable in histologically normal tissue derived from the corresponding contralateral thyroid lobes. Examples include a 750-bp v6- and v7-containing PCR product and a 650-bp v8- and v9- containing PCR product. Finally, a novel 530-bp PCR product was discovered and shown to contain a subsegment from exon 4 joined to a subsegment of exon 13 (v8), followed by the complete sequence of exons 14 (v9) and 15 (v10). This novel isoform was present in both the papillary cancers and contralateral tissues. In conclusion, papillary thyroid cancers exhibit specific patterns of aberrant alternative CD44 splicing, distinguishing them from histologically normal thyroid tissue.

Renal cortical neoplasm in a child with dialysis-acquired cystic kidney disease

Acquired cystic disease of the kidney is a common phenomenon in long-term adult dialysis patients with endstage renal disease. Malignant degeneration with cortical neoplasms is also well documented in this patient population. Although the prevalence of this disease process is common in adults, the literature is sparse concerning its occurrence in children. To our knowledge, we report the youngest case of renal cortical neoplasm associated with dialysis-acquired renal cystic disease in a 13-year-old boy.

P-glycoprotein expression in the squamous cell carcinoma of the tongue base

P-glycoprotein (PGP), which is a product of the multidrug resistance gene (MDR1), is an active transmembrane efflux pump responsible for detoxifying normal cells as well as rendering tumor cells resistant to chemotherapy. It has also been implicated to be expressed by more aggressive cancers. It has not been well described in squamous cell carcinoma of the head and neck. In this investigation, an attempt was made to characterize advanced squamous cell carcinoma of the base of tongue with respect to expression of PGP. Using immunohistochemical techniques two anti-PGP monoclonal antibodies (JSB1 and C494) were used to detect PGP in these lesions, and an attempt was made to correlate levels of PGP staining and various tumor parameters. Usefulness of PGP in predicting survival and time to recurrence was also examined for these advanced lesions. All 33 base of tongue lesions showed staining for PGP with these monoclonal antibodies. This was the first study examining utility of C494 in detecting PGP in squamous cell carcinoma at this site. Increased level of PGP expression was seen in better-differentiated tumors as well as in tumors with diploid DNA. A trend of higher PGP expression and decreased survival emerged. This may represent a true relationship, but inherent heterogeneity of PGP expression within cells cannot be excluded. Both antibodies examined appear to be useful in the investigations of PGP distribution in squamous cell carcinomas of the head and neck sites by immunohistochemical techniques. Prognostic value of the level of PGP expression remains to be seen.

Deregulated alternative splicing of CD44 messenger RNA transcripts in neoplastic and nonneoplastic lesions of the human thyroid

CD44 is a polymorphic family of immunologically related cell surface proteoglycans and glycoproteins implicated in cell-cell and cell-matrix adhesion interactions, lymphocyte activation and homing, cell migration, and tumor metastasis. CD44 exists as a standard form and as multiple isoforms, each generated by alternative splicing of up to 10 variant exons (termed v1-v10) encoding parts of the extracellular domain. Using semiquantitative reverse transcriptase-PCR and Southern hybridization, alternative CD44 mRNA splicing was examined in 10 papillary thyroid carcinomas, 8 nodular goiters, 9 adenomas, 2 cases of thyroiditis, and 3 histologically normal thyroid controls. The amount of input cDNA for the CD44 PCRs was standardized against an internal control gene (glyceraldehyde phosphate dehydrogenase). Four papillary carcinomas showed significant overexpression of CD44 transcripts migrating between 750 and 1000 bp. These cases demonstrated reduced levels of the 482-bp standard isoform transcript. In six papillary cancers, we found a prominent v6-containing isoform at 750 bp that was present in only trace amounts in normal thyroid tissue. It is of interest that similar findings were seen in the majority of the goiters and adenomas but not in the cases of thyroiditis. These results show that deregulation of alternative CD44 splicing is a common feature of disordered thyroid follicular cell growth, both in neoplastic and nonneoplastic lesions. The data imply an important role for CD44, including CD44v6, in the pathogenesis of various thyroid lesions.

Nuclear accumulation of MDM2 protein in well-differentiated papillary thyroid carcinomas

Papillary thyroid cancer is the most common endocrine malignancy. Of all solid cancers presenting in adults, papillary thyroid cancer generally carries the best long-term prognosis. However, very little is understood about the molecular pathogenesis of this neoplasm. We recently hypothesized that increased nuclear levels of MDM2 protein might occur in well-differentiated papillary thyroid carcinomas (Gerasimov et al., Exp. Mol. Pathol. 62, 52-62, 1995). MDM2 is known to complex with and inactive the p53 tumor suppressor protein. Since p53 inactivation by gene mutation has an established role in the pathogenesis of undifferentiated (anaplastic) thyroid carcinoma, we reasoned that abrogation of p53 function by nuclear MDM2 protein accumulation might participate in the pathogenesis of certain well-differentiated thyroid cancers such as papillary cancer. In the present report we present the first direct evidence of MDM2 protein accumulation in the nuclei of papillary thyroid carcinoma cells in a subset of tumors. Using the IF-2 monoclonal antibody, which reacts specifically with human MDM2 protein, we studied 24 well-differentiated papillary thyroid carcinomas and 26 benign lesions (nodular goiters, adenomas, thyroiditis). Nuclear staining was quantitated using the CAS computerized image analysis system. We found positive nuclear MDM2 immunoreactivity in 8 (33%) of the carcinomas. In contrast, MDM2 staining was negative in all benign lesions (P = 0.001, two-tailed Fisher exact test). Normal thyroid tissue was also negative. These data suggest that nuclear accumulation of MDM2 protein might be implicated in the pathogenesis of a subset of papillary carcinomas. Further studies to investigate this possibility are warranted.

Nuclear p53 immunoreactivity in papillary thyroid cancers is associated with two established indicators of poor prognosis

The tumor suppressor protein, p53, protects somatic cells against the accumulation of genomic alterations. Cells harboring mutant or inactivated wild-type p53 protein are at risk for the development of genomic instability. Nuclear accumulation of p53 protein is associated with the stepwise dedifferentiation of papillary carcinoma. We asked whether nuclear p53 accumulation is associated with two known indicators of poor prognosis in papillary carcinoma. We studied 55 consecutive papillary cancers (28 from Russia, and 27 from upstate New York). Nuclear p53 immunoreactivity was assessed using a monoclonal antibody, DO-1, on Formalin-fixed paraffin-embedded specimens. The DNA index was determined by computerized image analysis of Feulgen-stained sections. Nearly all cases were well differentiated and none were associated with distant metastases or extrathyroidal invasion. All primary lesions were less than 4 cm in diameter, and almost all patients were female. Nuclear p53 immunoreactivity was associated with a high-risk group characterized by two known indicators of poor prognosis: age > 50, aneuploid DNA content, or both. In the high-risk group (N = 24) 33% of cases displayed nuclear p53 positivity, compared with only 6% in a low-risk group (N = 31) which lacked both features (P = 0.015, two-tailed Fisher exact test). Nuclear accumulation of immunoreactive p53 protein is associated with two established indicators of poor prognosis in papillary carcinoma of the thyroid. This result is consistent with the idea that aberrations in p53 function are associated with the stepwise loss of differentiation in this cancer.

Space adaptation syndrome is caused by elevated intracranial pressure

Space adaptation syndrome (SAS) incapacitates about 50% of the astronauts with symptoms of headache, malaise, vomiting, vertigo, etc. A hypothesis that SAS is caused by elevated intracranial pressure secondary to the cephalad fluid shift in zero G is proposed. A mechanism of how the cephalad fluid shift could cause elevated intracranial pressure is discussed. Factors known to alleviate and exacerbate SAS are interpreted in light of the elevated intracranial pressure mechanism.

High-dose short-term chlorambucil for intractable sympathetic ophthalmia and Behçet's disease

We treated five patients with intractable sympathetic ophthalmia and six patients with severe Behçet's disease by high-dose, short-term chlorambucil therapy. We used a total dose ranging from 306 mg to 4.2 g and a duration of therapy no longer than 36 weeks and in most cases less than 24 weeks. After termination of therapy all 11 patients had a sustained remission of their eye disease. Unless subretinal neovascularisation was present, all had a final visual acuity of 20/50 or better. Malignancy has not developed in any of our cases, with a follow-up ranging from 6 months to 12 years (mean, 4.5 years). Although 30- and 40-year follow-ups and larger numbers of patients may be necessary fully to realise the risks of chlorambucil, we believe that our high-dose, short-term regimen (Behçet's disease: average duration, 23 weeks; average total dose 2.2 g; sympathetic ophthalmia: average duration, 11 weeks; total average dose, 0.9 g) may be safer than previously reported chlorambucil regimens of one to two years or longer. In addition we fulfilled our aim of discontinuing all concomitant systemic corticosteroids within a relatively short time (usually six to eight weeks).

Sympathetic ophthalmia following neodymium:YAG cyclotherapy

Neodymium:YAG cyclotherapy has been demonstrated to lower intraocular pressure dramatically in patients with uncontrolled glaucoma, with potentially fewer side-effects than cyclocryotherapy. We report the clinical course and histopathological features of a case of sympathetic ophthalmia occurring soon after YAG cyclotherapy.

Twenty cases of sympathetic ophthalmia

We reviewed the charts of 20 patients with sympathetic ophthalmia who were seen in the uveitis clinic at the Eye and Ear Infirmary within an 11-year period. Of these 20 patients 14 maintained 20/50 or better visual acuity in at least one eye. We found early enucleation to be associated with a better visual prognosis, possibly due to earlier diagnosis and faster, more aggressive therapy rather than a reduction in antigenic load. The clinical appearance of Dalen-Fuchs nodules appears to indicate a more severe stage of disease. Chlorambucil was useful in patients with severe disease. To be effective and to lessen its side effects chlorambucil was given in daily dosages that were increased weekly over a short period to achieve bone marrow suppression. After a course of chlorambucil therapy intraocular inflammation could be controlled with topical steroids alone.

Study of neuromotor reaction times under the influence of thyrotropin-releasing hormone

Neuromotor reaction times (simple, choice, and decision) were measured when Thyrotropin-releasing hormone (TRH) was administered intravenously to nine healthy men in a double-blind study. Measurements were made of simple reaction time, choice reaction time, and decision time for each subject at various intervals over a 54-hr. period. Given the observed inherent interaction of the drug with the long time used (54 hr.), most analyses were conducted across separate time epochs. Injected subjects showed inhibition in the normal improvement of simple reaction time (which occurs with practice), and they reduced the time required to make a decision. Choice reaction time, however, remained unchanged across the drug-nondrug experimental conditions.

Effect of inspiratory volume on intrathoracic pressure generated by an L-1 maneuver

Since each muscle has an optimal length at which it can generate the maximum tension, an optimal inspiratory volume may exist for producing the maximum intrathoracic pressure during the L-1 maneuver. Intrathoracic pressures were measured in eight healthy men after they inspired various volumes of air and performed the L-1 straining maneuver in a 1-G environment. Both the peak and mean intrathoracic pressures increased at greater inspiratory volumes, except for the mean intrathoracic pressure at the highest volumes. The ability to increase intrathoracic pressure with larger inspiratory volumes may improve +Gz tolerance.

Effect of body inversion on hemodynamics determined by two-dimensional echocardiography

The purpose of this study was to determine if head-down inversion of normal men from a supine position would increase blood return to the heart. Eight healthy, normovolemic men were placed into 10 degrees, 30 degrees, 60 degrees, and 90 degrees head-down tilt positions. BP and two-dimensional echocardiograms were recorded at the supine baseline and immediately after inversion. There was no significant change in left ventricular end-diastolic volume, stroke volume, cardiac output, or BP with inversion, except for a significant increase in diastolic pressure at the 60 degree position. The efficacy of placing hypotensive shock patients in the head-down tilt position is discussed.

Completeness of infant death registration for very low birthweight infants: Washington State 1978-79

Washington State hospitals were queried about the fate of 507 infants born in 1978-79 for whom no linked death certificate existed. Only ten previously unregistered deaths were discovered, raising mortality for this group by 2.5 per cent. In addition, 13 previously unmatched death records were linked to birth records, providing more accurate calculation of birthweight-specific mortality rates. Washington State infant death registration is more complete that that found in either Georgia or North Carolina.

The mechanisms which affect the periodic cycle of Pacific Wuchereria bancrofti microfilariae

1. Investigations were made of the effect of various procedures in raising or lowering the microfilaria count of Pacific type Wuchereria bancrofti in the peripheral blood. 2. Raising the body temperature in the early morning was followed by a moderate fall in the counts. Breathing increased oxygen, or reduced oxygen (hypoxia) or increased carbon dioxide, or the ingestion of sodium bicarbonate produced no consistent and significant change in the count. Ingestion of glucose (in one volunteer) was followed by a small rise in the count. Muscular exercise was followed by a fall in the count, which is interpreted as probably being a response to a lower concentration of oxygen in the venous blood returning to the lung. 3. It has not been possible to identify the physiological components on the circadian rhythm of the human body which entrain the cycle of these microfilariae. Attempts to obtain evidence incriminating the stimuli described above have been unsuccessful.

A growth factor from spinal cord

Mitogenic activity is present at a variety of sites in the central nervous system. A growth factor was purified from neonatal bovine spinal cord. It has a pI of 9.5-9.8 and a molecular weight of about 11,000 daltons. Spinal cord growth factor is a basic polypeptide that is inactivated by extremely acid or basic conditions. Its mobility on SDS polyacrylamide gels suggests that this factor is different from pituitary FGF and brain FGF-1.