Pneumothorax and other lung diseases: effect of altered resolution and edge enhancement on diagnosis with digitized radiographs

Prior studies have shown that pneumothorax is one of the more difficult entities to diagnose with digitized radiography. This study was designed to test whether increasing resolution from 1.25 to 2.5 line pairs per millimeter (lp/mm) and image processing (edge enhancement from unsharp masking) would increase accuracy and confidence in the diagnosis of pneumothorax, as well as normal cases and other forms of lung disease. Conventional radiographs were digitized with use of a laser reader and then reformatted as film hard copy. Eleven observers read 35 cases reformatted in three different ways (1.25 lp/mm, 2.5 lp/mm, 1.25 lp/mm unsharp mask). The images with finer resolution (2.5 lp/mm) and unsharp mask images were superior to those with coarser resolution (1.25 lp/mm) for the diagnosis of pneumothorax. There was no difference in diagnostic accuracy for normal patients. For abnormalities other than pneumothorax, the unsharp mask images were significantly worse. Confidence in the diagnosis of pneumothorax and other abnormalities was highest with the finest resolution (2.5 lp/mm).     

Inoculation of newborn SWR/J females with an ecotropic murine leukemia virus can produce transgenic mice.

Endogenous ecotropic murine leukemia proviruses that were not present in the parental stock are acquired by the progeny of some SWR/J X RF/J hybrid females. We have made a stock of an ecotropic murine leukemia virus produced by such a hybrid female and inoculated newborn SWR/J females with it. We show that upon crossing of the inoculated females to SWR/J males, some of their progeny acquire ecotropic proviruses. Although most of these proviruses appear to be distributed in somatic tissues in a mosaic way, some are transmitted through the germ line. Thus an exogenous infection is able to mimic the phenomenon observed in SWR/J X RF/J hybrid mice. Available evidence suggests that this infection occurs during oogenesis in the recipient female. Our results document the conversion of an exogenous infectious ecotropic murine leukemia virus to an endogenous provirus without any manipulation of either eggs or embryos.     

Tracheobronchial necrosis after caustic ingestion.

Between 1968 and 1988, 679 patients were hospitalized for ingestion of caustic substances, and 87 had severe caustic burns of the entire esophagus, together with panparietal necrosis. Twenty-one of them had tracheobronchial necrosis with perforation. Fifteen have not been operated on; six have had operations, with success in four. We describe an original technique for repairing these tracheobronchial perforations with a pulmonary patch.     

AT base pairs are the main target for mutations at the hprt locus of rat skin fibroblasts exposed in vitro to the monofunctional alkylating agent N-ethyl-N-nitrosourea

Spectra of N-ethyl-N-nitrosourea (ENU)-induced mutations differwidely among various in vitro and in vivo mutational systems.To investigate possible reasons for these differences, a mutationalsystem is needed in which the same target gene is used for comparisonin the same type of cells in vitro and in vivo. In the presentstudy, this was achieved by analysing at the molecular level35 hprt mutant rat fibroblast clones obtained from cell populationsexposed in vitro to ENU and comparing the mutational spectrumwith the previously determined spectrum of ENU-induced hprtmutants in the same target cells exposed in vivo. Twenty-eightmutants contained a single base pair alteration in the hprtcoding sequence. Most of these changes were found at AT basepairs (19/28), the AT to TA transversion being the most frequentkind of mutation (12/19), which is probably caused by O²-ethylthymine.Transversions at AT base pairs showed all mutated T's to belocated in the nontranscribed strand of the hprt gene, suggestinga strand specific fixation of mutations induced by O²-ethylthymine,which appears to be a general feature of ENU- and ENNG-inducedhprt mutations in mammalian cells. GC to AT transitions, probablycaused by O⁶-ethylguanine, were detected at a lower frequency(7/28). This in vitro mutational spectrum was very similar tothat of the same target cells exposed in vivo to ENU. A comparisonof the mutational spectra in AGT-proficient and AGT-deficientrodent cells exposed to ethylating agents showed that in contrastto the situation in AGT-proficient rat fibroblasts, GC to ATbase pair changes (and not AT to TA) are the predominant mutationsin AGT-deficient hamster cells. ⁴To whom correspondence should be addressed     

Administration of Half-Dose Theophylline Together with Ketotifen to Asthmatic Children—A Double-Blind, Placebo-Controlled Study

Administration of theophylline to asthmatic children is frequently associated with an adverse influence on their behavior. The efficacy and behavioral effects of the administration of high-dose theophylline (T) and ketotifen (K) in various combinations were evaluated prospectively in a double-blind, placebo controlled study in 55 children with moderately severe perennial asthma. During a baseline period of 2 weeks, theophylline (serum level of 10-20 μg/ml) was administered to all the children. After this period the patients were randomly allocated into four comparable groups. The children were treated during a 12-week period with: T + K-Placebo (T group); T + K (T + K group); half-dose T + K (T/ 2 + K group); or placebo of both T and K (P group). During the 12-week treatment period, as compared to the baseline period, only the three groups of children who received active therapy (T + P, T + K, T/2 + K) showed a similar reduction in the number of days with asthmatic symptomatology, improvement of the total asthmatic symptoms score, and increased PEFR. The behavioral activity of the children (assessed by the Conner's rating scale) improved significantly only in the groups receiving placebo or T/2 + K. The results of this study suggest that a combination therapy of half the recommended therapeutic dose of theophylline with ketotifen can be clinically as effective as therapy with a full dose of theophylline, but with significantly less adverse behavioral effects.     

Role of transrectal ultrasonography in the evaluation of azoospermic men with low-volume ejaculate.

OBJECTIVE: The purpose of this prospective study was to evaluate the incidence of distal ejaculatory system defects with transrectal ultrasonography (TRUS) among patients evaluated for azoospermia. METHODS: Forty-two patients with low-volume ejaculate and azoospermia were evaluated by physical examination, serum follicle-stimulating hormone and luteinizing hormone level determination, karyotyping, selective screening for cystic fibrosis mutations, and TRUS. RESULTS: On physical examination, in 29 patients (69%), either 1 (12 patients) or both (17 patients) of the vasa deferentia could not be palpated. In the group of 17 patients with bilateral involvement of the vasa deferentia, the ultrasonographic imaging universally showed bilateral absence or hypoplasia of the seminal vesicles with bilateral agenesis of the vasa deferentia and nonvisualization of both ejaculatory ducts. In the patients with a unilateral abnormality on physical examination, the ultrasonographic imaging showed absence of the ipsilateral seminal vesicle in 7 patients and the hypoplastic seminal vesicle in 5. In the group of 13 patients with normal physical examination findings, a variety of obstructive causes were diagnosed by TRUS examination. CONCLUSIONS: According to this study, TRUS appears to be a sensitive method for evaluating the anatomy of the distal ejaculatory system. Its safety and low costs make it a good alternative to the other invasive and expensive methods.     

Anxiety and hippocampus volume in the rat.

In depressed patients as well as healthy controls, a positive relationship between hippocampal volume and trait anxiety has been reported. This study sought to explore the possible inter-relation between hippocampal volume and trait anxiety further. Magnetic resonance imaging at 7 T was used to measure hippocampal volumes in a rat model of extremes in trait anxiety (experiment 1) and in a Wistar population with normal anxiety-related behavior (experiment 2). In addition to anxiety-related behavior, potentially confounding factors (depression-like, exploratory, and locomotor behavior) were assessed. Experiment 1 globally supported the hypothesis of a positive relationship between hippocampus volume and trait anxiety but did not allow for ruling out possible confounds arising from cosegregation of other behavioral traits. Experiment 2 yielded strong evidence for a negative relationship which was specific for trait anxiety. Thus, the relationship between hippocampal volume and anxiety may be more complex than expected. Interestingly, anxiety-related behavior in experiment 2 had a stronger influence on hippocampal volume than depression-like behavior. In the light of hippocampal volume loss in anxiety disorder and frequent comorbidity of anxiety and depression, this finding suggests that further research into the relationship between anxiety and hippocampal volume may be critical for understanding hippocampal contributions to normal and pathological behavior.