Stimulation of Canine Gastric Motility by BRL 24924, a New Gastric Prokinetic Agent

We describe the actions and pharmacology of BRL 24924, a new gastric prokinetic agent, in conscious dogs. In Heidenhain pouch preparations, BRL 24924 (0.01–0.16 mg/kg i.v.) is a potent stimulant of interdigestive phasic motility (increases in intraluminal pressure), approximately 50 times more potent than metoclopramide. The stimulatory effect of BRL 24924 (0.025 mg/kg i.v.) was prevented by atropine (0.1 mg/kg s.c.). It was initially unaffected by hexamethonium (5 mg/kg i.v.), but hexamethonium prevented BRL 24924 from causing sustained stimulation of motility. The stimulatory activity of BRL 24924 (0.025 mg/kg i.v.) was unaffected by propranolol (3 mg/kg i.v.) or by phentolamine (1 mg/kg i.v.). The selective 5-hydroxytryptamine₃ receptor antagonist granisetron (BRL 43694; 0.1 or 1.0 mg/kg i.v.) neither mimicked nor prevented the stimulatory actions of BRL 24924. In dogs with a gastric fistula, the gastric emptying of a liquid test meal was accelerated following BRL 24924 (0.1 mg/kg i.v.) but was unaffected by granisetron (0.1 and 1 mg/kg i.v.). We conclude that BRL 24924 is a potent, long-lasting, and effective stimulant of canine gastric motility, which accelerates gastric emptying. The pharmacology of BRL 24924 is discussed in terms of its relationship with myenteric 5-hydroxytryptamine receptors.     

A comparison of polymerase chain reaction and an infectivity assay for human immunodeficiency virus type 1 titration during virus inactivation of blood components

Three examples of human plasma-derived concentrates, intermediate- purity factors VIII and IX, and fibrinogen were spiked with tissue culture-grown human immunodeficiency virus type 1 (HIV-1) strain RF. All examples were freeze-dried and heated at 80 degrees C for 72 hours by using validated production process models. HIV-1 infectivity was measured by a syncytial infectivity assay in C8166 cells and then compared with levels determined by nested HIV polymerase chain reaction (PCR). The infectivity assay demonstrated a reduction index of at least 4.5 log10, while PCR showed an average 1.7 log10. Large amounts of HIV- 1 RNA (10(5)) were still detectable by PCR in samples in which infectivity assays failed to detect any HIV-1. These data suggest that HIV-1 PCR levels do not parallel HIV-1 infectivity levels during virus- inactivation procedures involved in coagulation factor concentrate production. PCR was able to detect the RNA associated with inactivated HIV-1 particles in the factor concentrates, which allows the conclusion that PCR is not a useful test with which to monitor virus-inactivation procedures such as heating at 80 degrees C for 72 hours. This judgment contrasts with the more definite and sensitive role of PCR in diagnosing HIV-1 infection in patients in whom a positive HIV-1 PCR result correlates with active HIV-1 infection and with PCR's usefulness in monitoring virus removal.     

MASSIVE LOWER GASTROINTESTINAL HAEMORRHAGE SECONDARY TO METASTATIC SQUAMOUS CELL CARCINOMA OF THE LUNG

SUMMARY Clinically significant symptoms due to gastrointestinal metastases from primary lung cancers is rare. A case of life-threatening lower gastrointestinal haemorrhage secondary to metastatic squamous cell carcinoma of the lung is reported. Previous reports of such metastases are reviewed, with reference to management and prognosis. After resection of colonic metastases from squamous cell lung cancer, survival is similar to that for primary disease. It is suggested that patients with known or suspected squamous cell lung cancer presenting with lower gastrointestinal symptoms be managed as aggressively as those with no previous history of disease.     

Infiltrative lamina propria invasion pattern as an independent predictor for cancer‐specific and overall survival of instillation treatment‐naïve stage T1 high‐grade urothelial bladder cancer

Objectives

To investigate established prognostic factors and relatively new histopathological tumor characteristics including metric substage and lamina propria invasion patterns in a large series of T1 high‐grade non‐muscle‐invasive bladder cancer.

Methods

Between 1989 and 2012, 322 patients with initial stage T1 high‐grade bladder cancer underwent transurethral resection, followed by re‐transurethral resection and a conservative approach with follow‐up regime alone or instillation treatment. Transurethral resection specimens were reassessed by two experienced urological pathologists for tumor grade according to the World Health Organization 1973 classification, metric T1 substage, lamina propria invasion pattern and associated carcinoma in situ. The median follow‐up period was 42 months (interquartile range 25–72 months). In addition to Kaplan–Meier analyses, uni‐ and multivariable Cox regression analyses were used to compare progression‐free survival, cancer‐specific survival and overall survival for the studied parameters comparing two subcohorts.

Results

While in patients after instillation treatment no examined feature was shown as an independent predictor for prognosis, there were predictive histopathological features in multivariable Cox regression analyses in instillation treatment‐naïve patients: associated carcinoma in situ (hazard ratio 2.278, 95% confidence interval 1.119–4.634, P = 0.023) and World Health Organization 1973 grade 3 (hazard ratio 2.950, 95% confidence interval 1.021–8.536, P = 0.046) for worse progression‐free survival, infiltrative lamina propria tumor pattern for worse cancer‐specific survival (hazard ratio 2.369, 95% confidence interval 1.034–5.429, P = 0.042) and overall survival (hazard ratio 1.049, 95% confidence interval 1.024–1.075, P = 0.001).

Conclusions

The results of the present T1 high‐grade bladder cancer series suggest that lamina propria invasion pattern is a promising parameter to predict the prognosis of T1 high‐grade bladder cancer in an instillation treatment‐naïve subcohort. Prospective multicenter evaluations are warranted. The need for instillation treatment in T1 high‐grade bladder cancer is clearly demanded.     

Aberrant immunoglobulin class switch recombination and switch translocations in activated B cell-like diffuse large B cell lymphoma

To elucidate the mechanisms underlying chromosomal translocations in diffuse large B cell lymphoma (DLBCL), we investigated the nature and extent of immunoglobulin class switch recombination (CSR) in these tumors. We used Southern blotting to detect legitimate and illegitimate CSR events in tumor samples of the activated B cell-like (ABC), germinal center B cell-like (GCB), and primary mediastinal B cell lymphoma (PMBL) subgroups of DLBCL. The frequency of legitimate CSR was lower in ABC DLBCL than in GCB DLBCL and PMBL. In contrast, ABC DLBCL had a higher frequency of internal deletions within the switch mu (Smu) region compared with GCB DLBCL and PMBL. ABC DLBCLs also had frequent deletions within Sgamma and other illegitimate switch recombinations. Sequence analysis revealed ongoing Smu deletions within ABC DLBCL tumor clones, which were accompanied by ongoing duplications and activation-induced cytidine deaminase-dependent somatic mutations. Unexpectedly, short fragments derived from multiple chromosomes were interspersed within Smu in one case. These findings suggest that ABC DLBCLs have abnormalities in the regulation of CSR that could predispose to chromosomal translocations. Accordingly, aberrant switch recombination was responsible for translocations in ABC DLBCLs involving BCL6, MYC, and a novel translocation partner, SPIB.     

Increased rates of punished responding produced by buspirone-like compounds in rats.

Buspirone has been reported to have effects on punished responding in rats which are considerably smaller and less reliable than those produced by benzodiazepines. A recent study, however, found that buspirone and ipsapirone increased operant responding suppressed by a stimulus which preceded unavoidable shock, suggesting that conditioned emotional response protocols may be more sensitive than punishment procedures. This hypothesis was not supported by the results of the present study. The food-reinforced lever pressing of rats was maintained by a multiple VI schedule with punished and unpunished components. The experimental parameters were similar to those used in the previous conditioned emotional response study. The benzodiazepines, chlordiazepoxide and clorazepate, as well as buspirone (at one dose) and ipsapirone (at several doses), increased rates of punished responding. The 5-hydroxytryptamine-1A receptor ligands 8-hydroxy-2-(di-n-propylamino)tetralin and MDL 73005EF did not reliably produce similar effects, although increased rates of punished responding were seen in some animals. Haloperidol, imipramine and idazoxan did not increase punished response rates. Although the increases in punished responding produced by buspirone were smaller than those produced by chlordiazepoxide and clorazepate, the effect of ipsapirone was quantitatively similar to that of the benzodiazepines.     

Cognitive deficits are associated with unemployment in adults with sickle cell anemia

An estimated 25–60% of adults with sickle cell disease (SCD) are unemployed. Factors contributing to the high unemployment rate in this population are not well studied. With the known risk of cognitive deficits associated with SCD, we tested the hypothesis that unemployment is related to decrements in intellectual functioning. We conducted a retrospective chart review of 50 adults with sickle cell anemia who completed cognitive testing, including the Wechsler Adult Intelligence Scale–IV, as part of standard care. Employment status was recorded at the time of testing. Medical variables examined as possible risk factors for unemployment included disease phenotype, cerebral infarction, and pain frequency. The mean age of the sample was 30.7 years (range = 19–59); 56% were women. Almost half of the cohort (44%) were unemployed. In a multivariate logistic regression model, lower IQ scores (odds ratio = 0.88; p = .002, 95% confidence interval, CI [0.82, 0.96]) and lower educational attainment (odds ratio = 0.13; p = .012, 95% CI [0.03, 0.65]) were associated with increasing odds of unemployment. The results suggest that cognitive impairment in adults with sickle cell anemia may contribute to the risk of unemployment. Helping these individuals access vocational rehabilitation services may be an important component of multidisciplinary care.     

Effects of d-amphetamine on the behavior of pigeons maintained by a second-order schedule of reinforcement.

The effects of various doses of d-amphetamine were studied on the responding of two pigeons exposed to a second-order schedule of reinforcement. With this schedule, food was presented following the completion of a sequence of three 2-minute fixed-interval components. A visual stimulus was presented at the completion of each fixed interval, including the one which was terminated with food. The pigeons' behavior was characterized by a pause immediately after each stimulus presentation followed by a gradual increase in response rate as the interval progressed. d-Amphetamine was found to increase the low rates of responding which occurred early in each interval and to decrease the high rates of responding at the end of each interval. These effects occurred whether responding preceded the presentation of food or the brief stimulus alone.