Someone to talk to? The role of loneliness as a factor in the frequency of GP consultations

BACKGROUND

There are many reasons why people frequently consult their general practitioner (GP). Although loneliness is increasingly recognized as a problem affecting well-being for elderly people, it has rarely been addressed as a predictor of frequency of consultation.

AIM

To examine whether loneliness is associated with rates of GP consultations (home and surgery visits).

METHOD

Analysis of data collected in face-to-face interviews at the second wave of a longitudinal health survey of two adult age cohorts living in four socially contrasting urban localities in Glasgow City. There were a total of 691 subjects: 142 males and 176 females aged 40 years at interview; and 167 males and 206 females aged 60 years at interview. Frequency of reported GP consultations in the past 12 months at home or in the surgery was examined.

RESULTS

After controlling for sociodemographic and socioeconomic variables and health, loneliness was significantly associated with frequency of consultation at the surgery but not with the frequency of home visits.

CONCLUSION

Loneliness may still be underestimated as a factor related independently to frequency of consultations with a GP at the surgery.

Modelling of the disulphide-swapped isomer of human insulin-like growth factor-1: implications for receptor binding

Insulin-like growth factor-1 (IGF-1) is a serum protein which unexpectedly folds to yield two stable tertiary structures with different disulphide connectivities; native IGF-1 [18-61,6-48,47-52] and IGF-1 swap [18-61,6-47, 48-52]. Here we demonstrate in detail the biological properties of recombinant human native IGF-1 and IGF-1 swap secreted from Saccharomyces cerevisiae. IGF-1 swap had a approximately 30 fold loss in affinity for the IGF-1 receptor overexpressed on BHK cells compared with native IGF-1. The parallel increase in dose required to induce negative cooperativity together with the parallel loss in mitogenicity in NIH 3T3 cells implies that disruption of the IGF-1 receptor binding interaction rather than restriction of a post-binding conformational change is responsible for the reduction in biological activity of IGF-1 swap. Interestingly, the affinity of IGF-1 swap for the insulin receptor was approximately 200 fold lower than that of native IGF-1 indicating that the binding surface complementary to the insulin receptor (or the ability to attain it) is disturbed to a greater extent than that to the IGF-1 receptor. A 1.0 ns high-temperature molecular dynamics study of the local energy landscape of IGF-1 swap resulted in uncoiling of the first A-region alpha-helix and a rearrangement in the relative orientation of the A- and B-regions. The model of IGF-1 swap is structurally homologous to the NMR structure of insulin swap and CD spectra consistent with the model are presented. However, in the model of IGF-1 swap the C-region has filled the space where the first A-region alpha-helix has uncoiled and this may be hindering interaction of Val44 with the second insulin receptor binding pocket.

Confirmation of linkage in X-linked infantile spasms (West syndrome) and refinement of the disease locus to Xp21.3-Xp22.1

The syndrome of infantile spasms, hypsarrhythmia, and mental retardation (West syndrome) is a classical form of epilepsy, occurring in early infancy, which is etiologically heterogeneous. In rare families, West syndrome is an X-linked recessive condition, mapped to Xp11.4-Xpter (MIM 308350). We have identified a multi-generation family from Western Canada with this rare syndrome of infantile spasms, seen exclusively in male offspring from asymptomatic mothers, thereby confirming segregation as an X-linked recessive trait. Using highly polymorphic microsatellite CA-repeat probes evenly distributed over the entire X chromosome, linkage to markers DXS7110, DXS989, DXS1202, and DXS7106 was confirmed, with a maximum LOD score of 3.97 at a theta of 0.0. The identification of key recombinants refined the disease-containing interval between markers DXS1226 and the adrenal hypoplasia locus (AHC). This now maps the X-linked infantile spasms gene locus to chromosome Xp21.3-Xp22.1 and refines the interval containing the candidate gene to 7.0 cM. Furthermore, this interval overlaps several loci previously linked with either syndromic or non-syndromic X-linked mental retardation (XLMR), including one recognized locus implicated in neuroaxonal processing (radixin, RDXP2). Collectively, these studies lend strong support for the presence of one or more genes intrinsic to brain development and function, occurring within the critical interval defined between Xp21.3-Xp22.1.

The medical dictionary for regulatory activities (MedDRA)

The International Conference on Harmonisation has agreed upon the structure and content of the Medical Dictionary for Regulatory Activities (MedDRA) version 2.0 which should become available in the early part of 1999. This medical terminology is intended for use in the pre- and postmarketing phases of the medicines regulatory process, covering diagnoses, symptoms and signs, adverse drug reactions and therapeutic indications, the names and qualitative results of investigations, surgical and medical procedures, and medical/social history. It can be used for recording adverse events and medical history in clinical trials, in the analysis and tabulations of data from these trials and in the expedited submission of safety data to government regulatory authorities, as well as in constructing standard product information and documentation for applications for marketing authorisation. After licensing of a medicine, it may be used in pharmacovigilance and is expected to be the preferred terminology for international electronic regulatory communication. MedDRA is a hierarchical terminology with 5 levels and is multiaxial: terms may exist in more than 1 vertical axis, providing specificity of terms for data entry and flexibility in data retrieval. Terms in MedDRA were derived from several sources including the WHO's adverse reaction terminology (WHO-ART), Coding Symbols for a Thesaurus of Adverse Reaction Terms (COSTART), International Classification of Diseases (ICD) 9 and ICD9-CM. It will be maintained, further developed and distributed by a Maintenance Support Services Organisation (MSSO). It is anticipated that using MedDRA will improve the quality of data captured on databases, support effective analysis by providing clinically relevant groupings of terms and facilitate electronic communication of data, although as a new tool, users will need to invest time in gaining expertise in its use.

Impaired splenic function and tuftsin deficiency in patients with intestinal failure on long term intravenous nutrition

BACKGROUND

Reticuloendothelial system function is impaired in humans receiving lipid regimens.

AIMS

To evaluate the effects of long term administration of long chain triglyceride emulsions on reticuloendothelial system function.

METHODS

Splenic function and tuftsin activity were measured in 20 patients on intravenous nutrition for intestinal failure, 20 patients with Crohn's disease who were not receiving intravenous nutrition, and 50 healthy controls.

RESULTS

Pitted red cells counts in patients on intravenous nutrition (8.0%) were significantly higher (p<0.001) than in healthy controls (0.6%) and in patients with Crohn's disease (0.9%). No difference was found between healthy controls and patients with Crohn's disease. There was a correlation (r=0.50; p<0.03) between percentage of pitted red cells and duration of intravenous nutrition. Tuftsin activity was significantly reduced in the intravenous nutrition patient group (6%) compared with both disease controls (16.5%, p<0.01) and healthy volunteers (17.8%, p<0.001). An inverse correlation between tuftsin activity and pitted red cell percentage was found in the patients on intravenous nutrition (r(s) =-0.44, p<0.05). No relation was found in the patients on intravenous nutrition between pitted red cell percentage or tuftsin activity and type of disease, percentage of ideal body weight, residual length of small intestine, or administration (quantity and frequency) of lipid emulsion. Eight patients on intravenous nutrition had serious infections within the previous 12 months.

CONCLUSIONS

Patients with a short bowel treated with long term intravenous nutrition have impaired splenic function, reduced tuftsin activity, and an increased risk of infection.

HLA associations of seropositive rheumatoid arthritis in a Cree and Ojibway population

OBJECTIVE

To determine the HLA associations of seropositive rheumatoid arthritis (RA) in a Cree and Ojibway population; to determine whether specific alleles distinguish juvenile or adult onset.

METHODS

HLA-A, B, C, and DRB1 alleles were analyzed in 23 Ojibway and Cree patients with RA seen in a single tertiary care center. Comparisons were made with published results of controls and with results of 18 patients with rheumatoid factor (RF) positive polyarticular juvenile rheumatoid arthritis (JRA) from the same population.

RESULTS

Comparisons among patients with RA, patients with RF positive polyarticular JRA, and controls showed increased frequencies of the RA shared epitope in patients with RA and of DRB1*0901 in patients with seropositive polyarticular JRA, while the frequency of DRB1*08 alleles was decreased in patients with RF positive polyarticular JRA.

CONCLUSION

In this population, DRB1*0901 may promote while DRB1*08 alleles may protect against a juvenile onset of RA specifically. In contrast, the RA shared epitope may have a greater effect on the risk of adult onset seropositive RA. Due to the small patient numbers, these results require confirmation.

Anomalous screening outcomes from click-evoked otoacoustic emissions and auditory brainstem response tests

Transiently evoked otoacoustic emissions (TEOAE) and auditory brainstem response (ABR) tests were used in parallel to screen 862 neonates with risk factors for hearing loss. Seven neonates (0.81%) passed on TEOAE screen yet failed on ABR in one ear (six neonates) or both ears (one neonate). This combination of results has been termed 'anomalous'. Examination of audiometric results obtained on follow-up shows that in one ear of one neonate the result was consistent with the later confirmed audiogram shape. The explanation for the anomalous results in the remaining ears is unclear although neural maturation and the effects of hyperbilirubinaemia are possibilities. There were no instances of progressive or retrocochlear hearing loss identified. None of the seven neonates had better ear hearing loss of > or = 40 dB on long term follow-up.

The use of enteral and parenteral feeding

Nutritional support involves a number of disciplines; collaborative decision-making by a nutrition support team is recommended. Unless factors exist which preclude enteral feeding or make the exclusion of nutrients from the gut appropriate, every effort should be made to feed enterally. Nutritional support involves the provision of safe equipment, treatment protocols and procedures, a training programme for all staff involved in the patient's care, and an audit system.

Apathy, depression, and cognitive performance in HIV-1 infection

The authors examined the relationship between apathy, depression, and cognitive performance in 48 HIV-1-seropositive and 21 seronegative (control) subjects, using reaction time (RT) and working memory tasks. Apathy, but not depression, was associated with working memory deficits among HIV-seropositive subjects. The cognitive-affective component of the Beck Depression Inventory (BDI), but not apathy, was associated with slowing and decreased accuracy on a choice RT task. The BDI cognitive-affective component was more closely associated than the BDI somatic component with both RT slowing and apathy. Results suggest that prominent symptoms of apathy, independent of depression, may be an important indicator of CNS involvement in HIV infection. Total BDI scores showed a less consistent relationship with neurocognitive performance, suggesting that somatic symptomatology is diagnostically ambiguous among HIV-infected subjects.

Human SLUG gene organization, expression, and chromosome map location on 8q

SLUG is a member of the snail family of zinc finger proteins. It is involved in epithelial to mesenchyme cell transition during neurulation and plays a role in limb bud development. We have isolated and described the human SLUG gene by sequencing a region spanning 4034 bp. The human SLUG gene contains three exons. The SLUG transcript is 2.2 kb and is found in placenta and adult heart, pancreas, liver, kidney, and skeletal muscle, and it codes for a protein of 268 amino acids and 29.989 kDa. This protein contains five zinc finger regions. The human SLUG protein is 95, 93, and 88% homologous to mouse, chicken, and Xenopus slug, respectively, but shows only 47% homology to mouse Snail. The zinc finger region is 100% identical between human and mouse Slug. Slug maps to the long arm of chromosome 8, closely linked to D8S2090 between D8S519 and D8S1098.

Renal transplantation following renal failure due to urological disorders

BACKGROUND

Renal allograft outcome, during an 8 year period (1985-1992), has been assessed in 56 renal transplants performed in 55 patients who had end-stage renal failure as a consequence of urological abnormalities. The abnormalities were: primary vesicoureteric reflux (VUR) or renal dysplasia (26 patients); posterior urethral valves (PUV) (15); neuropathic bladders (6); vesico-ureteric tuberculosis (5); bladder exstrophy (3); and prune belly syndrome (1). Six patients had augmented bladders, and eight transplants were performed in seven patients with urinary diversions.

RESULTS

Overall, 1 and 5 year actuarial graft survival was 89 and 66%, with mean creatinine of 154 micromol/l +/- 11 (SE) and 145 +/- 9 respectively. Patients with abnormal bladders or conduits (n = 28) had worse graft function than those with normal bladders (n = 28) although graft survival was not significantly different in the two groups at 1 and 5 years: 93 and 75% with normal bladders vs 86 and 57% with abnormal systems. Symptomatic urinary tract infections were common in the first 3 months after transplantation (63%); fever and systemic symptoms occurred in 39% with normal bladders and 59% with abnormal bladders. Urinary tract infection directly contributed to graft loss in six patients with abnormal bladders, but had no consequences in those with normal bladders.

CONCLUSIONS

Abnormal bladders must be assessed urodynamically before transplantation, and after transplantation adequacy of urinary drainage must be re-assessed frequently. Prophylactic antibiotics are now given for the first 6 months and urinary tract infections must be treated promptly. With these measures, good results, similar to those of patients without urological problems, can be obtained.

Effect of arsenite on induction of CYP1A and CYP2H in primary cultures of chick hepatocytes

In earlier studies, treatment with sodium arsenite was shown to decrease total hepatic CYP in rats. A concomitant increase in heme oxygenase, the rate-limiting step in heme degradation to biliverdin, was considered responsible for the decrease in CYP. Here we investigated the effect of sodium arsenite on induction of CYP2H, CYP1A, and heme oxygenase in primary cultures of chicken embryo hepatocytes. When added simultaneously with inducer, arsenite inhibited phenobarbital-mediated increases in CYP2H and 3-methylcholanthrene-mediated increases in CYP1A, as measured enzymatically and immunochemically. Near maximal decreases were observed in these forms of CYP at a concentration of 2.5 microM sodium arsenite. The concentration-dependent decreases in CYP2H and CYP1A by sodium arsenite were concomitant with increases in heme oxygenase. Sodium arsenite was not toxic at concentrations as high as 10 microM, as indicated by protein synthesis and the reduction of MTT by intact cells. Sodium arsenite had no effect on induction of CYP2H1 mRNA, suggesting that the decreases in this form of CYP occurred post-transcriptionally. Treatment of cells with tin mesoporphyrin (SnMeso), an inhibitor of heme oxygenase, resulted in inhibition of arsenite-induced heme oxygenase. However, SnMeso did not alter the effect of arsenite to prevent phenobarbital-mediated increases in CYP2H protein. SnMeso alone inhibited phenobarbital-mediated increases in CYP2H. Inclusion of 2 or 5 microM exogenous heme with arsenite did not prevent the arsenite-mediated decrease in CYP2H. Combined treatment with heme and phenobarbital induced heme oxygenase to the same extent as treatment with heme, arsenite, and phenobarbital. However, CYP2H activity was decreased only when the treatment included arsenite. These results suggest that elevated levels of heme oxygenase alone are not responsible for arsenite-mediated decreases in CYP2H.

Alcohol-mediated increases in acetaminophen hepatotoxicity: role of CYP2E and CYP3A

This commentary focuses on the roles of CYP3A and CYP2E in alcohol-mediated increases in acetaminophen hepatotoxicity. CYP2E has been considered to be the main form of P450 responsible for such toxicity in animals and humans. However, CYP3A, which is also induced by alcohol, has been shown to have a greater affinity for acetaminophen than CYP2E. Previous experiments implicating CYP2E in alcohol-mediated increases in acetaminophen hepatotoxicity have used inhibitors of this form of P450 that are now proving to be non-specific. Triacetyloleandomycin (TAO) is a potent inhibitor of CYP3A that maintains specificity in vitro over a large concentration range. In rats treated with ethanol or the combination of ethanol and isopentanol, the major higher chain alcohol in alcoholic beverages, TAO protects animals from increases in acetaminophen hepatotoxicity, suggesting a major role of CYP3A. CYP2E may not have a major role due to the rapid loss of induced levels in the absence of continued exposure to ethanol. Knockout mice, which are being used to define the role of particular proteins in biological responses, have been developed for CYP2E1 and CYP1A2 but not CYP3A. Cyp2e1(-/-) and Cyp1a2(-/-) mice are more resistant to acetaminophen hepatotoxicity than wild-type strains, even though the amounts of the other forms of P450s are unaltered in the liver. These findings suggest that the relative amounts of P450s and not just kinetic characteristics determine their role in acetaminophen hepatotoxicity. The clinical implications of the findings that CYP3A can have a major role in acetaminophen-mediated hepatotoxicity are discussed.

Juvenile rheumatoid arthritis in a Canadian First Nations (aboriginal) population: onset subtypes and HLA associations

OBJECTIVE

To determine onset subtypes and HLA associations of juvenile rheumatoid arthritis (JRA) in a First Nations (aboriginal) population; to determine whether population frequencies of HLA antigens may explain the distribution of subtypes of JRA in this population.

METHODS

All patients were children from Manitoba and Northwestern Ontario seen in a single pediatric rheumatology clinic between 1975 and 1996. Patients were identified from a clinic registry. Controls were adults of Algonkian Cree and Ojibway heritage. Class I and II major histocompatibility (HLA) typing was performed for First Nations patients and controls.

RESULTS

There were a total of 74 First Nations patients with JRA. The relative frequency of rheumatoid factor (RF) positive polyarticular JRA was higher and that of pauciarticular JRA was lower in First Nations compared with Caucasian patients (42 versus 3% and 22 versus 58%, respectively; p = 0.00000). HLA-DRB1*04 (63%), 08 (43%), and 1402 (25%) were the most common DRB1 antigens among controls. The main subtypes of DRB1*04 were 0404 (33% of controls) and 0407 (23%). HLA typing was performed for 39 First Nations patients; 27 were Cree or Ojibway, 4 were from other tribes, and 8 were part First Nations. Among Cree and Ojibway, 59% of controls and 63% of patients with RF positive polyarticular JRA (n = 16) had HLA-DRB1 antigens bearing the rheumatoid arthritis (RA) shared epitope (OR 1.16, 95% CI: 0.38, 3.48). The OR for polyarticular RF positive JRA in those with DRB1*0802 and 0901 were 0.15, 95% CI: 0.02; and 1.24 and 5.83, 95% CI: 1.58, 28.38, respectively.

CONCLUSION

There was a high frequency of the RA shared epitope represented by both HLA-DRB1*0404 and 1402 in this Algonkian population. This high frequency may explain the high frequency of RF positive polyarticular JRA. DRB1*0802 may be protective, whereas DRB1*0901 may increase the risk for this subtype of JRA.

Field sensitivity of targeted neonatal hearing screening using the Nottingham ABR Screener

OBJECTIVE

A population of children having bilateral moderate to profound hearing impairment was investigated to find out the number who passed (false negatives) and who failed (true positives) a screening test based on the auditory brain stem response (ABR).

DESIGN

This study of the ABR is a parallel report to Lutman, Davis, Fortnum, and Wood (1997), where the transient evoked otoacoustic emission was examined on a similar but not identical population of at-risk neonates. Hearing screening was undertaken in at-risk neonates (targeted screening) at seven hospitals in the UK using the Nottingham ABR Screener. During the period from January 1988 to December 1993, a total of 6983 neonates had been tested. Assessment of audiological records from the participating centers ascertained that 201 children born between January 1988 and December 1993 had hearing threshold levels in both ears of 50 dB or more, averaged over the speech frequencies 0.5, 1, 2, and 4 kHz. Of these, 51 had completed the ABR screening test. Examination of the ABR records, which included both machine and visual scoring, indicated whether they had passed or failed the screening test.

RESULTS

Forty-six of the 51 hearing impaired babies failed the neonatal ABR screen either on one or both ears (five false negatives), and 42 failed the test on both ears (nine false negatives). This resulted in field sensitivities of 90% and 82%, respectively. Two cases of suspected progressive hearing loss have been included in the numbers of false negative results. The percentage of babies passing the screen on both ears and subsequently having normal hearing (specificity) is typically 93%.

CONCLUSIONS

Neonatal hearing screening in an at-risk population using a highly automated ABR test is a viable and effective tool for identification of hearing impairment. Although the field sensitivity of the test is high, it is unable to identify all babies with a criterion level of hearing loss. There are a number of possible explanations as to the origin of false negative results: configuration of the pure-tone audiogram, a progressive hearing loss, acquired sensorineural or conductive loss, retrocochlear deafness, or an incorrect interpretation of the screening test. Passing a neonatal screening test, therefore, does not exclude the possibility of subsequent hearing impairment and highlights the need for further surveillance.

Identification of an immunodominant IgE epitope of the Parietaria judaica major allergen

Par j 1.0101 is one of the two major allergens of the Parietaria judaica (Pj) pollen, and its three-dimensional structure was built by three-dimensional structural homology modeling. The resultant model was used to identify putative IgE binding regions. Western blot analysis of gene fragmentation products showed that the 1 to 30 region was capable of binding specific IgE from a pool of sera (n = 30) of patients allergic to Pj pollen. Using the structural model as a guide, deletion and site-directed mutagenesis of the 1 to 30 region was performed, and the amino acids involved in IgE binding were identified. In addition, a synthetic peptide covering the 1 to 30 region was capable of binding human IgE without triggering histamine release from basophils of Pj allergic patients (n = 6) and thus represents a haptenic molecule with potential use as an immunotolerant agent. This epitope is also present on the Par j 2.0101 major allergen representing a common IgE epitope. It is an immunodominant epitope, since it was capable of inhibiting 30% of all specific IgE against the Pj major allergens, and therefore, it might be a candidate for the future development of immunotherapeutics.