Long-term cognitive deficits in patients after surgery on aneurysms of the anterior communicating artery.

The long term recovery of a series of 27 patients who had undergone rupture and repair of an aneurysm of the anterior communicating artery was assessed using a number of neuropsychological measures. Testing took place 12 to 84 months post surgery. On the basis of the results from tests of intellect, memory, and conceptual learning, three subgroups of patients were identified: those with persuasive cognitive defects, those with evidence of residual frontal lobe damage and those who showed no evidence of dysfunction. The occurrence of cerebral vasospasm was the most consistent predictor of long term cognitive deficit.     

Microalbuminuria in diabetes: relationships between urinary albumin excretion and diabetes-related variables

A single observer reviewed 842 of the 917 known diabetic patients registered with 40 GPs in the Poole area. Fifty-nine per cent (493) of those reviewed submitted a timed overnight urine collection to measure albumin excretion rate (AER) and overnight albumin/creatinine ratio (ON-Alb/Creat); 43 samples were excluded because of urinary tract infection and/or proteinuria. A random urine sample was obtained in 607 diabetic patients to measure the random albumin/creatinine ratio (R-Alb/Creat); 68 specimens were excluded because of infection and/or proteinuria, and in a further 10 samples urinary creatinine was not measured. Stepwise multiple regression analyses found significant associations with the following variables: for AER, blood glucose (p = 0.001), smoking category (p = 0.002), sex (p = 0.034), and systolic blood pressure (p = 0.035); for R-Alb/Creat, blood glucose (p = 0.001), retinopathy (p = 0.004), systolic blood pressure (p = 0.004), diastolic blood pressure (p = 0.015), coronary artery disease (p = 0.02), sex (p = 0.034), and vibration sense (p = 0.038). Interestingly, glycosylated haemoglobin was not a significant determinant of albuminuria in either analysis.     

The pharmacological properties of the imidazobenzodiazepine, FG 8205, a novel partial agonist at the benzodiazepine receptor

1. The pharmacological properties of the benzodiazepine receptor ligand, FG 8205 (7-chloro-5,6-dihydro-5-methyl-6-oxo-3-(5-isopropyl-1,2,4-oxadiazol++ +-3-yl)-4H- imidazol[1,5a][1,4]benzodiazepine) have been examined. 2. FG 8205 potently displaced [3H]-flumazenil binding in rat cortical membranes with a Ki of 3.3 nM, but was inactive at 13 neurotransmitter recognition sites. 3. Consistent with a partial agonist profile, the affinity of FG 8205 for the benzodiazepine recognition site was increased in the presence of gamma-aminobutyric acid (GABA, 300 microM) by a degree (-log [IC50 in the presence of GABA/IC50 alone] = 0.34) significantly less than found for diazepam (0.46). FG 8205 also potentiated the inhibitory potency of the GABAA-receptor agonist, isoguvacine, on the hippocampal CA1 population spike and, again, the maximum shift (-log dose-ratio = 0.2) was significantly less than that seen with diazepam (0.4). 4. In anticonvulsant studies, the ED50 doses of FG 8205 and diazepam needed to antagonize seizures induced by pentylenetetrazol (PTZ) or by sound in audiogenic seizure prone mice were similar with values of 0.2-0.3 mg kg-1, i.p. However, even high doses of FG 8205 (50 mg kg-1) did not protect against seizures induced by electroshock. 5. FG 8205 released responding suppressed by footshock in a rat operant conditioned emotional response task over the dose range 0.5-50 mg kg-1 (i.p.). Similar doses of FG 8205 had a marked taming effect in cynomolgus monkeys.(ABSTRACT TRUNCATED AT 250 WORDS)     

Configurational changes within the dermis of meshed split skin grafts: a histological study

By placing a series of vertical cuts through the skin graft, the meshing process increases the area of exposed dermis. This extra dermis contains the cut ends of vessels derived from the subpapillary plexus. Histological examination has shown that each of the skin bridges within the mesh changes shape so that these vessels come to open on to the undersurface of the graft, where they are advantageously placed to participate in revascularisation of the graft.     

Developing a Peer Review Process for Web-based Curricula

The World Wide Web creates new challenges and opportunities for medical educators. Prominent among these are the lack of consistent standards by which to evaluate web-based educational tools. We present the instrument that was used to review web-based innovations in medical education submissions to the 2003 Society of General Internal Medicine (SGIM) national meeting, and discuss the process used by the SGIM web-based clinical curriculum interest group to develop the instrument. The 5 highest-ranked submissions are summarized with commentary from the reviewers.     

Inhaled allergen-driven CD1c up-regulation and enhanced antigen uptake by activated human respiratory-tract dendritic cells in atopic asthma

Background Dendritic cells (DC) mediate inflammation in rodent models of allergic airway disease, but the role played by human respiratory‐tract DC (hRTDC) in atopic asthma remains poorly defined. Recent data suggest that CD1 antigen presentation by hRTDC may contribute to asthma pathogenesis. Objective To investigate the influence of hRTDC on the balance between atopy and allergic asthma in human subjects and to determine whether CD1 expression by hRTDC is modulated during asthmatic inflammation. Methods Sputum cells were induced from steroid‐naïve, allergen‐challenged and allergen‐naïve subjects (atopic asthmatics, atopic non‐asthmatics and non‐atopic controls). hRTDC were identified using monoclonal antibody labelling and analysis by flow cytometry. Results hRTDC stained HLA‐DR⁺ (negative for markers of other cell lineages) were predominantly myeloid and comprised ∼0.5% of viable sputum cells. Sputum cells were potent stimulators of allogeneic CD4⁺ naïve T cells and enrichment/depletion experiments correlated stimulatory potency with DC numbers. Sputum contained cells that exhibited typical dendritic morphology when analysed by electron microscopy. Myeloid hRTDC were endocytically active, but uptake of FITC‐dextran was enhanced in cells from asthmatics (P<0.001). Despite their increased endocytic capacity, asthmatic myeloid hRTDC appeared mature and expressed increased levels of maturation markers (P<0.05–P<0.001), CD1c, CD1d and langerin (P<0.05). CD1c expression by asthmatic myeloid hRTDC was enhanced upon in vivo allergen challenge (three to ninefold within 24 h; P<0.05). CD11c⁻CD123^high hRTDC were only detected in asthmatic sputum and were increased in number following allergen challenge. Conclusion Despite limited cell numbers, it proved possible to analyse human RTDC in induced sputum, providing evidence that increased antigen uptake and enhanced CD1 presentation by activated hRTDC may contribute to allergic airway disease. CD1 presentation by hRTDC in atopic asthma may therefore constitute a novel target for future intervention strategies.     

An in vivo investigation into bond failure rates with a new self-etching primer system.

Self-etching primers have recently been introduced to simplify the orthodontic bonding process. The aim of this study was to compare the effectiveness of such a product with conventional 2-stage etching and priming with 37% o-phosphoric acid and a conventional unfilled primer. Twenty consecutive patients having orthodontic bonds placed were selected to participate in this cross-mouth control study. Diagonally opposite quadrants were randomly allocated to either the self-etching primer group or the conventional etching and priming group. A total of 364 teeth were bonded with a light-cured diacrylate adhesive; bond failures were then monitored over 6 months. There were 20 bond failures (10.99%) in the self-etching primer group and 9 bond failures (4.95%) in the conventional etch and priming group over this period. The results were analyzed with the McNemar test and 95% confidence interval. The difference between the failure proportions was -0.06 with an associated 95% confidence interval of -0.121 to 0.001. This study produced weak evidence to suggest that bond failures with a self-etching primer will be higher than those with conventional etching and priming. This increased likelihood of bond failure must be weighed against the time advantage of the self-etching primer when used at the initial bonding appointment.     

Constitutive secretion of the granule chymase mouse mast cell protease-1 and the chemokine, CCL2, by mucosal mast cell homologues

BACKGROUND: The mucosal mast cell (MMC) granule-specific beta-chymase, mouse mast cell protease-1 (mMCP-1), is released systemically into the bloodstream early in nematode infection before parasite-specific IgE responses develop and TGF-beta1 induces constitutive release of mMCP-1 by homologues of MMC in vitro. Intraepithelial MMC may also express the chemokine CCL2 (monocyte chemotactic protein-1) during nematode infection but the expression of this chemokine by MMC homologues has not been investigated. OBJECTIVE: To investigate the expression and to compare the mechanisms of constitutive release of the chymase, mMCP-1, and the chemokine, CCL2. METHODS: MMC homologues were generated by culturing bone marrow cells in the presence of TGF-beta1, IL-3, IL-9 and stem cell factor (SCF). The intracellular distribution of mMCP-1 and CCL2 was examined by confocal microscopy. The involvement of the Golgi complex and of protein synthesis in the constitutive release of mMCP-1 and CCL2 was investigated using the Golgi-disrupting agent brefeldin A and cycloheximide to block protein synthesis. Secreted analytes were quantified by ELISA. RESULTS: mMCP-1 colocalized with Golgi matrix protein 130 but was most abundant in the granules, whereas CCL2 was not found in the granules but appeared to be located uniquely in the Golgi complex. Extracellular release of mMCP-1 was significantly inhibited ( approximately 40%) by cycloheximide and by the Golgi-disrupting agent brefeldin A, indicating both continuous protein synthesis and transportation via the Golgi complex are required for optimal mMCP-1 secretion. A similar but more marked inhibitory effect with both compounds was demonstrated on the constitutive secretion of CCL2. CONCLUSION: The culture conditions that promote mMCP-1 expression and release by MMC homologues also promote the expression and release of CCL2. Constitutive release involves de novo protein synthesis and requires a functional Golgi complex, suggesting that similar mechanisms of extracellular secretion operate for both mediators.     

A double-blind, placebo-controlled study of the effect of imipramine on TRH-induced urinary urgency in healthy men.

We studied the effect of imipramine (IMI) on thyroid releasing hormone (TRH)-induced urinary urgency as a way of investigating the mechanism of the beneficial effect of IMI on enuresis. In a double-blind study, 12 normal, healthy men between 21 and 39 yr of age ranked their urge to urinate at 30-sec intervals following IV injection of TRH (500 micrograms) or saline. The subjects then were randomly assigned to either IMI (1 mg/kg) or placebo groups for 10 days, and the procedure was repeated. Compared to saline, TRH produced a significant elevation in urinary urgency in all subjects. IMI did not significantly blunt TRH-induced urinary urgency. Thus, the mechanism by which IMI affects enuresis is likely not mediated at the level of the urinary urgency induced by TRH.