Ethological Problems with the Interpersonal Theory of Suicide.

Joiner and colleagues' Interpersonal Theory of Suicide (IPTS), a prominent "desire-capability" model of suicide-based on the common-sense idea that people take their own lives because they want to, and can-is critiqued from a biological perspective. Tinbergen's ethological "four questions" guide the analysis: evolution, survival value, ontogeny, and proximate causation, each addressing a different aspect of biological understanding. Problems for IPTS emerge with all four. As a parsimonious solution, the desire-capability hypothesis is reconceived as an ultimate, instead of proximate, mode of explanation. By this light, desire and capability for suicide combined in our species' ancestral past, thus making suicide a recurrent survival threat, and driving the evolution of special-purpose defensive adaptations. This stance tallies with the pain-brain theory of the evolution of suicide, and with Joiner and colleagues' own investigation into organismic anti-suicide defenses, which appears to conflict conceptually with IPTS. These defenses' evolved algorithm may make suicide an intrinsically aleatory phenomenon, opaque to usefully accurate prediction. Positive implications for prevention and research are proposed.

Daptomycin-Induced Posterior Reversible Encephalopathy Syndrome (PRES).

AIMS: To present a 60-year-old female patient who manifested clinical and radiological features of posterior reversible encephalopathy syndrome (PRES) following the administration of Daptomycin for glycopeptide-resistant Enterococcal urinary tract infection. MATERIAL: Case report. METHOD: Posterior reversible encephalopathy syndrome was diagnosed in our patient following the administration of Daptomycin based on clinical suspicion as well as brain CT and MRI imaging. RESULTS: The temporal association between the initiation of Daptomycin and the onset of PRES is highly suggestive of causality, and this is further supported by clinical and radiological resolution after Daptomycin was withdrawn. CONCLUSION: This is the first report of Daptomycin-induced posterior reversible encephalopathy syndrome.

Clinical, radiological and serum amyloid P component scintigraphic features of beta2-microglobulin amyloidosis associated with continuous ambulatory peritoneal dialysis.

BACKGROUND: Beta2-Microglobulin (beta2M) amyloidosis occurs in patients with end-stage renal failure (ESRF) who undergo long-term continuous ambulatory peritoneal dialysis (CAPD), but its prevalence in patients treated exclusively by CAPD is unknown. In addition, its features may differ from those of haemodialysis-associated beta2M amyloidosis because CAPD is more biocompatible. METHODS: We performed serum amyloid P component (SAP) scintigraphy, a specific technique for imaging amyloid deposits, in 13 consecutive patients with ESRF who had been dialysed for >5 years, at least 80% of the time by CAPD. Clinical and radiological features of beta2M amyloidosis were sought and compared with the results of SAP scintigraphy. RESULTS: SAP scans showed articular amyloid deposits in seven patients, all of whom had evidence of carpal tunnel syndrome and four of whom had arthralgia characteristic of dialysis amyloidosis. Typical radiographic bone cysts were present in only one case who had been dialysed for >17 years. The remaining six patients had no clinical, radiological or scintigraphic evidence of beta2M amyloidosis. CONCLUSIONS: The prevalence of beta2M amyloidosis in this study was comparable with that in reported haemodialysis populations. Many of the amyloid deposits demonstrated by SAP scintigraphy were not associated with symptoms, but larger and longer term studies are required to determine whether CAPD favourably influences their clinical expression.

Incidence of childhood-onset Type 1 diabetes mellitus in Devon and Cornwall, England, 1975-1996.

AIMS: To determine the incidence of Type 1 diabetes mellitus (DM) in children aged 0-15 years in the far south-west of England between 1975 and 1996. METHODS: Patient information was collected to set up the Cornwall and Plymouth Children's Diabetes Register (CPCDR) through two main data sources; hospitals and the general practitioners in all surgeries in the study region. All children under 16 years living within Cornwall and the Isles of Scilly, and the former Plymouth Health Authorities and diagnosed as having Type 1 DM during the study period were included. The case ascertainment was estimated by a capture-recapture method. Trends and differences in incidence of sex, age, time period and district of diagnosis were analysed by Poisson regression analysis. Roger's method was used to estimate the seasonal variations. RESULTS: A total of 522 subjects aged between 0 and 15 years were identified from 01/01/1975 to 31/12/1996, giving an overall crude incidence of 14.9/ 100 000 population/year. The case ascertainment was 94.4% (95% confidence interval (CI) 91.4- 97.6%) for the whole register. Poisson regression analysis showed that a significant increase of incidence (2.49% per year) was observed throughout the 22-year study period, which was mainly a result of the significant increase in the 0-4 year age-group (6.29% per year). The incidence significantly differed among the 22-years (P = 0.007), the three age groups (0-4, 5-9 and 10-14 years, P<0.001) and different sexes (P=0.049). The significant seasonal variations were detected with peak incidence appearing in autumn and winter. CONCLUSIONS: The first validated childhood-onset diabetes register has been set up in the far south-west of England. The incidence of childhood Type 1 DM in this region has increased significantly over the past two decades, especially in children under 5 years.

Long-term glycaemic control directly correlates with glomerular filtration rate in early Type 1 diabetes mellitus before the onset of microalbuminuria.

Hyperfiltration occurs early in diabetes mellitus and has been implicated in the development of microalbuminuria. Our aim was to re-examine the controversial relationship between glycaemic control and glomerular filtration (GFR) in normoalbuminuric, normotensive, non-obese patients with short duration Type 1 diabetes mellitus (DM). We studied 75 Type 1 DM patients, 35 male, aged 18-42 years, with a duration of diabetes of 4-8 years. GFR was determined by inulin clearance; hyperfiltration was defined as above 145 ml min(-1) 1.73 m(-2) (equivalent to 2 SD above mean for a control population). Analysis was by paired Student's t-testing and linear regression. GFR correlated significantly with HbA1c (r= 0.47, p < 0.0001) and fructosamine (r= 0.24, p = 0.035). Mean HbA1c and fructosamine in the 13 patients with hyperfiltration was significantly higher than in the rest of the group (HbA1c: 9.2% (95% C.I. 7.9-10.4%) vs 7.6 % (7.2-7.9), p= 0.002; fructosamine: 479 micromol l(-1) (450-507) vs 410 micromol l(-1) (388-432), p = 0.009. This significant difference persisted even when the two highest values of HbA1c or fructosamine were removed from analysis. Effective renal plasma flow, assessed by PAH clearance, also correlated in all patients with HbA1c (r=0.31, p=0.039). We conclude that poor glycaemic control directly correlates with hyperfiltration and renal hyperperfusion in early Type 1 DM.

Biological indicators for steam sterilization: characterization of a rapid biological indicator utilizing Bacillus stearothermophilus spore-associated alpha-glucosidase enzyme.

The alpha-glucosidase enzyme was isolated from vegetative cells and spores of Bacillus stearothermophilus, ATCC 7953. Spore-associated enzyme had a molecular weight of approximately 92,700, a temperature optimum of 60 degrees C, and a pH optimum of 7.0-7.5. The enzyme in crude aqueous spore extract was stable for 30 min up to a temperature of 65 degrees C, above which the enzyme was rapidly denatured. The optimal pH for stability of the enzyme was approximately 7.2. The alpha-glucosidase in crude vegetative cell extract had similar characteristics to the spore-associated enzyme but its molecular weight was 86,700. The vegetative cell and spore-associated enzymes were cross-reactive. The enzymes are postulated to derive from a single gene product, which undergoes modification to produce the spore-associated form. The location of alpha-glucosidase in the spore coats (outside the spore protoplast) is consistent with the location of most enzymes involved in activation, germination and outgrowth.

Biological indicators for low temperature steam and formaldehyde sterilization: investigation of the effect of change in temperature and formaldehyde concentration on spores of Bacillus stearothermophilus NCIMB 8224.

Five strains of Bacillus stearothermophilus have been studied to identify a spore strain to be used as a biological indicator organism for low temperature steam and formaldehyde sterilization. Three strains gave poor reproducibility of batch size and growth index and were discarded. The other two strains gave good reproducibility with a high growth index and gave rise to linear survivor curves when exposed to 5% aqueous formaldehyde. However, only NCIMB 8224 sporulates on a simpler medium and as it was the most resistant to formaldehyde, it was further studied. Tests were carried out in a modified miniclave and factors studied included temperature of the steam and formaldehyde concentration. All studies confirmed the suitability of this strain as a biological indicator organism.

Biological indicators for low temperature steam and formaldehyde sterilization: the effect of defined media on sporulation, growth index and formaldehyde resistance of spores of Bacillus stearothermophilus strains.

Preliminary screening was carried out on spores of 29 strains of Bacillus stearothermophilus to determine their potential as biological indicator organisms for low temperature steam and formaldehyde sterilization. Each strain was sporulated on four chemically defined media. Fourteen strains produced satisfactory sporulation on one or more of the media but there was considerable variation in the extent of sporulation. The growth index of the spores, which was dependent on both the strain of organism and the sporulation medium, ranged from 1% to 90%. The spores were appraised on the basis of their resistance to inactivation by 0.5% w/v formaldehyde in aqueous solution at 70 degrees C. The survivor curves obtained could be characterized into five types on the basis of the shape of the curve. Only five strains of Bacillus stearothermophilus produced spores with the characteristics of high resistance, linear semi-logarithmic survivor curve and high growth index that would be required of a potential biological indicator organism.

Characteristics of ulcers of the small bowel induced by non-steroidal anti-inflammatory drugs in the rat: implications for clinical practice.

Small bowel ulcers were created in the rat after the oral administration of non-steroidal anti-inflammatory drugs (NSAIDs). Of the six NSAIDs tested, indomethacin and diclofenac alone were associated with such damage which did not occur in a simple dose-related fashion. Bacteria were observed by electron microscopy in an active state of division in the base of the ulcers. When grown aerobically these were shown to be strains of Escherichia coli and Proteus mirabilis. Anatomically, NSAID-induced ulcers were found throughout the length of the bowel although more abundant in the proximal half. In vivo and in vitro sensitivity to antibiotics suggested that in addition to the bacteria identified, anaerobic beta-lactamase-producing organisms also have an important role in ulcer production in this model. This rat model of NSAID-induced gut toxicity is discussed in relation to the human situation, particularly for patients who take NSAIDs and who have an iron-deficiency anaemia and blood in their faeces, but no lesions in either the upper or lower bowel.

An automated enzymatic inulin assay, capable of full sinistrin hydrolysis.

Renal inulin clearance remains the standard by which other methods of measuring glomerular filtration rate are judged. A fully automated enzymatic assay capable of use with linear configuration inulin was recently published (Summerfield AL, et al. Clin Chem 1993; 39:2333-7). Sinistrin, a readily soluble preparation of polyfructan with side branching, is more suitable for clinical use and far more widely used in Europe. By modifying the incubation phase of samples with inulinase, incorporating a kinetic modification to the method of fructose analysis, and increasing the buffer strengths, we report a fully automated system, with minimal sample prehandling capable of complete sinistrin hydrolysis, and adapted for use on the Cobas Mira.