Influence of spatial and temporal manipulations on the anxiolytic efficacy of chlordiazepoxide in mice previously exposed to the elevated plus-maze

It has been widely reported that the anxiolytic efficacy of benzodiazepines in the elevated plus-maze test is abolished in subjects (rats or mice) that have been given a single prior undrugged experience of the test apparatus. The present series of experiments was designed to further characterise the key experiential determinants of this intriguing phenomenon in Swiss Webster mice. Using a standard 5 min test duration for both trials, Experiment 1 confirmed the anxiolytic efficacy of chlordiazepoxide (CDP; 5-20 mg/kg) in mice naive to the plus-maze, but a virtual elimination of drug effects in animals that had been pre-exposed to the maze 24 h earlier. Experiments 2 and 3 demonstrated that, while extending the duration of initial exposure to 10 min did not prevent the loss of CDP (10 mg/kg) efficacy in a standard-duration second trial, increasing the duration of both trials reinstated an anxiolytic profile for the compound. Finally, although trial 1 confinement to an open arm did not compromise CDP efficacy when animals were subsequently allowed to freely explore the maze (Experiment 4), closed arm confinement during initial exposure abolished the drug's anxiolytic action upon retest (Experiment 5). In contrast to previous findings in rats, these data suggest that the experientially induced loss of benzodiazepine efficacy in the mouse plus-maze depends rather critically upon prior discovery and exploration of relatively safe areas of the maze (i.e. closed arms). Results are discussed in relation to the hypothesis that the absence of an anxiolytic response to benzodiazepines in plus-maze-experienced subjects reflects the acquisition of an open arm phobia during trial 1.     

Does financial hardship account for elevated psychological distress in lone mothers?

Lone mothers have been shown to have higher levels of psychological distress than married mothers, but it is not clear how this difference arises. Using data from the 1958 British birth cohort followed to age 33, we investigated alternative explanations for the excess distress of lone mothers. Logistic regression models were used to estimate odds ratios for distress (measured using the Malaise Inventory) in lone vs married mothers. Odds ratios were adjusted to assess the contribution of explanatory factors. At age 33, psychological distress was greater among lone than married mothers (OR 2.59, 95% CI 1.97, 3.41). The odds ratio decreased to 1.43 (95% CI 1.02, 2.01) after adjustment for all explanatory factors (prior psychological distress, age of youngest child and number of children in the household, and contemporary measures of financial hardship, employment, and social support). Attenuation of the odds ratio was most marked after taking account of financial hardship. Psychological distress was greater among divorced mothers than never married mothers, though not significantly (OR = 1.70, 95% CI 0.88, 3.28). This difference was not explained by the factors examined, and was not due to the immediate distress associated with a recent divorce. Elevated psychological distress of lone mothers appears to be related to financial hardship, while other explanations, including social support and selection, have a more modest impact. Not all of the elevated psychological distress among lone mothers was accounted for, particularly among divorced lone mothers.     

Different behavioural profiles of the R(+)- and S(-)-enantiomers of 8-hydroxy-2-(di-n-propylamino) tetralin in the murine elevated plus-maze

(=) 8-Hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) has been the most widely used pharmacological tool in research on 5-HT(1A) receptor function. In the present study, the behavioural effects of 8-OH-DPAT entantiomers were compared using an ethological version of the murine elevated plus-maze test. Subcutaneous pretreatment (-20min) with R(+)-8-OH-DPAT (0.03-1.0mg/kg) produced a pronounced; and dose-dependent behavioural suppression (decreased open/closed/total arm entries and increased nonexploratory behaviours). In contrast, over the same dose range, S(-)-8-OH-DPAT reduced several ethological indices of anxiety without altering the majority of conventional parameters or general activity levels, e.g. arm entries and per cent time measures, as well as head dipping. Findings are discussed in relation to differences in the intrinsic activity of 8-OH-DPAT isomers at 5-HT(1A) sites and the putative role of these receptors in anxiety-related processes. The differential behavioural profiles of 8-OH-DPAT enantiomers suggest that racemic 8-OH-DPAT may not be an ideal tool for research on the behavioural pharmacology of 5-HT(1A) receptors.     

Hydrops of the gallbladder in children

Gallbladder disease in children today is being diagnosed increasingly because of better awareness of its existence and of improved diagnostic capability. A case is presented to describe an unusual pathologic variant termed "acute hydrops" of the gallbladder. This entity occurs specifically in children and is characterized by an acute illness with massive distention of the gallbladder in the absence of stones, bacteria, or congenital malformations. Differential diagnoses include appendiceal abscess, intussusception, volvulus, peritonitis, and pyelonephritis. Routine and contrast radiographic techniques may be combined with abdominal ultrasound to aid in the preoperative diagnosis. The etiology of hydrops is not known, but bile stasis and mesenteric lymphadenitis seem to be important factors. Treatment has varied from supportive observation to operative aspiration or cholecystectomy.     

Psychometric differentiation of biogenic and psychogenic impotence

In a sequential clinical sample of 64 subjects exclusively diagnosed as either biogenically or functionally impotent, Minnesota Multiphasic Personality Inventory (MMPI) and California Psychological Inventory (CPI) standard scales and the Beutler, et al., MMPI signs were all found to be ineffective in realiably classifying patients into the correct diagnostic groupings. Specific item analysis of the MMPI and CPI did identify a significant number of significantly differentiating individual items. Most of these items were shown to be reliably characterizable as indicating either performance anxiety or somatic complaint. Using these classifications of the items, the performance anxiety items were shown, consistent with theory, to be clearly associated with the functional impotence group. The somatic complaint items were shown to be clearly associated with the biogenic impotence group, presumably reflecting the symptoms of physiopathology, such as diabetes, underlying the biogenic condition.     

Crystalluria in marathon runners

Summary In order to investigate further the possible relationship between urinary stone formation and marathon running, the crystalluria in seven male, stone forming runners was characterized. Particle size distribution curves (Coulter counter) and crystal number, size and morphology (scanning electron microscopy) were measured. These studies suggest that urinary stone formation may be accelerated in those subjects with previous histories of renal stone formation but that the nature of the crystalluria is favourably affected by an increase in fluid intake. The presence of large quantities of mucoid material in the urine of natural stone formers and its absence in the urine of stone-forming runners is cited as evidence for the existence of different aetiological mechanisms in these groups. It is concluded that while natural stone formers may be at chronic risk of stone formation due to pathological factors, marathon runners may be at acute risk due to factors associated with long distance running itself.     

A new model for experimental tendon adhesions in the chicken

A minimally invasive model using a manual abrader to induce adhesions in the chicken's central digit is described. The flexor synovial sheath and the profundus tendon were abraded with access through small flaps at the level of the proximal and distal phalanges of the avian long toes. The birds were divided into two groups according to the severity of the induced trauma. Group I birds received an abrasion injury and were euthanized to allow biomechanical testing 5 weeks postoperatively. Group II birds had a more severe abrasion and were euthanized similarly and tested 5 weeks after surgery. Results were compared with nonsurgical controls. Long toe function was evaluated weekly by measuring (1) the range of active flexion of each interphalangeal joint, resolved to total angular range; (2) the grasping ability on graded-diameter perches; and (3) the flexion deficit of the long toe. Postmortem biomechanical properties of the adhesions were measured. There was a significant difference between the unoperated controls and abraded digits of both groups in all parameters (p < 0.001). There was, in addition, a marked change in most of the measured parameters between groups I and II. In group I digits the functional and biomechanical deficit was less than group II. In summary, this animal model of long-segment abrasive injury to the tendon and sheath is a simple and reproducible method to generate adhesions and can be used for the evaluation of treatment modalities for adhesion prevention.     

A prospective study of the correlation between genital pathogens and morbidity following diathermy loop excision of the transformation zone.

A prospective study of 48 women was carried out to estimate the incidence of common genital pathogens in women referred to colposcopy clinic requiring diathermy loop excision and to compare patient morbidity in the subgroups with and without genital pathogens. Of the 43 women included in the analysis, genital pathogens were present in 24 cases (56%) and absent in 19 (44%) of the 24 positive cases, 19 (79%) women had pathogen(s) on the cervical swab, 24 (100%) had pathogen(s) on the high vaginal swab and 15 (63%) had both a positive cervical and high vaginal swab (HVS). The most frequently isolated groups of organisms were mixed anaerobes, alone (four HVS and four cervical) or in combination with Gardnerella vaginalis (four HVS and three cervical) or coliforms (two HVS and two cervical). The mean duration of bleeding and vaginal discharge in the two study groups was not statistically significant (t value 1.97, P 0.05; and t value 0.48, P 0.5, respectively). However, the mean duration of bleeding graded by the patient as being moderate to severe was significantly different in the two groups (t value 3.18 P 0.01). Fifty-six per cent of the women in the study had confirmed genital pathogens, predominantly anaerobes, and the prolonged moderate-to-severe bleeding in this group suggests a potential role for prophylactic bacteriocides, although the study size was unable to implicate a single pathogen.