Hepatitis B prevalence in Denmark - an estimate based on nationwide registers and a national screening programme, as on 31 December 2007.

The prevalence of chronic hepatitis B virus (HBV) infection in Denmark is not clear. The primary aim of this study was to estimate the prevalence of chronic HBV infection in Denmark. The capture­recapture method was used to estimate the total population diagnosed with chronic HBV infection in Denmark using four nationwide registers. The population with undiagnosed chronic HBV infection was estimated by incorporating data from a two-year nationwide HBsAg screening programme in pregnant women. We identified 4,466 individuals with chronic HBV infection in the four registers until the end of 2007, and the capture­recapture estimate of the total population diagnosed with chronic hepatitis B was 7,112 (95% confidence interval (CI): 6,953­10,747). Only 17% of the identified patients attended recommended clinical care according to national guidelines. Including undiagnosed patients, the current population alive with HBV infection was 10,668 (95% CI: 10,224­16,164), corresponding to a prevalence of 0.24% (95% CI: 0.23­0.37%) in the Danish population older than 15 years. The estimated prevalence of chronic HBV infection among adults in Denmark was lower than reported from other northern European countries. Only half of the infected population had been diagnosed, and a minority attended specialised clinical care.

Chemical and biological evaluation of Egyptian Nile Tilapia (Oreochromis niloticas) fish scale collagen.

Collagen is considered to be one of the most useful biomaterials with different medical applications. However, collagen properties differ from one source to another. The aim of this study was to extract, purify, characterize and perform preliminary biological evaluation of type I collagen from scales of Egyptian Nile Tilapia. Pepsin-solubilized collagen (PSC) was successfully prepared from Nile Tilapia fish scale waste. Lyophilized collagen was dissolved in dilute HCl to form acidic collagen solutions (ACS) which was neutralized to form gel. To confirm the biocompatibility of the produced gel, baby hamster kidney (BHK-21) fibroblast cells were seeded onto a 3D collagen gel (0.3% and 0.5%, w/v). The results of an SDS-PAGE test showed that the extracted collagens were type I collagen, with α chain composition of (α1)2α2. Thermal analysis showed that the denaturation temperature was 32 °C. X-ray diffraction (XRD) analysis and Fourier-transform infrared spectra (FTIR) showed that the extracted collagen had a triple helix structure. Active proliferation of BHK-21 cells with no signs of toxicity was evident with both collagen gel concentrations tested. The results show that Nile Tilapia scales can be an effective source of collagen extraction that could be used as a potential biomaterial in biomedical applications.

Angiotensin II/aldosterone dose-response curves in the dog: effect of changes in sodium balance.

The possibility that the responsiveness of plasma aldosterone concentration to angiotensin II alters with changes in sodium balance was investigated in male beagle dogs under conditions of controlled sodium and potassium intake. Angiotensin II was infused at four different rates (usually 3, 6, 12, and 24 ng/kg/min), each for 1 h, 1) after periods of normal sodium diet (32 mEq/day), 2) after moderate sodium depletion (negative cumulative sodium balance 25-58 mEq), 3) after severe sodium depletion (65-116 mEq negative cumulative sodium balance), and 4) after sodium loading (150-212 mEq positive sodium balance), daily potassium intake remaining constant (26 mEq/day) throughout. Angiotensin II/aldosterone dose-response curves after moderate sodium depletion were both elevated and steepened in comparison with those found during normal sodium intake. Severe sodium depletion was associated with even greater elevation of dose-response curves, but individual aldosterone responses to angiotensin II were irregular and unpredictable. Sodium loading significantly diminished aldosterone responsiveness to angiotensin II. Blood pressure increments during angiotensin II infusion were attenuated by sodium depletion.

Inoculum type does not affect overall resistance of an arbuscular mycorrhiza-defective tomato mutant to colonisation but inoculation does change competitive interactions with wild-type tomato.

• The influence of inoculum type on colonisation of a mycorrhiza-defective tomato mutant, rmc, by the AM fungus Glomus coronatum was studied by comparing inoculum composed predominantly of spores with hyphae growing from mycorrhizal 'nurse plants', including the wild-type tomato progenitor (WT), other Lycopersicon species, and leek. • Colonisation of rmc was not primarily influenced by inoculum source; minor differences could be attributed to differences in inoculum potential. The mutation is therefore different from other mycorrhiza-defective tomato mutants. • Growth of rmc was reduced in the presence of nurse plants, because of competition with them, so a second experiment examined the effects of AM colonisation on competition between rmc and the WT tomato. This experiment was a replacement series in which rmc and WT were grown in competition and as single plants, inoculated with G. coronatum or uninoculated. • The WT did not respond to G. coronatum when grown alone, but responded positively when in competition with rmc. We conclude from the second experiment that mycorrhizal responsiveness is influenced by competition with (in this case) a surrogate nonhost plant rmc in a situation that mimics interspecific competition. It is therefore a community-based parameter. Results are discussed in the context of responses of mycorrhizal vs nonmycorrhizal species and competition in natural plant ecosytems.

Ultrastructural effects of topical timolol on the rabbit cornea. Outcome alone and in conjunction with a gas permeable contact lens.

Corneal epithelial erosions developed in two patients wearing gas permeable contact lenses (Boston) soon after commencing topical timolol maleate therapy. This prompted the following investigation. Forty rabbit corneas were examined by scanning and transmission electron microscopy after treatment for one month with one of the following: timolol ophthalmic solution, preservative-free timolol, contact lens, contact lens and timolol, contact lens and preservative-free timolol, contact lens and saline, or no treatment. Corneas treated with either timolol or contact lens alone showed mild to moderate edema or degeneration of epithelial and endothelial cells. However, the combined use of a contact lens and timolol produced marked alterations in both the corneal epithelium and endothelium.

A rat model of bacterial keratitis. Effect of antibiotics and corticosteroid.

A model of bacterial keratitis in rats was developed to quantify the effect of antibiotics and corticosteroid on the infective process. Corneas were inoculated with Staphylococcus aureus, Pseudomonas aeruginosa, or Streptococcus pneumoniae. The natural history of infection with these organisms was determined. Groups of animals received topical antibiotics and prednisolone acetate. The effect of treatment on the number of leukocytes and viable bacteria in the corneas was determined. Prednisolone did not influence the effect of the antibiotics; however, steroid treatment alone increased the pseudomonad count as much as 20-fold above the count in untreated eyes. In general, both the antibiotic and steroid treatments were more successful when begun eight hours after infection than when begun at 24 hours. a 1% gentamicin sulfate preparation proved effective against each of the infections, including a pneumococcal strain considered resistant on the basis of in vitro tests.

Capture-recapture estimates of drug misuse in urban and non-urban settings in the north east of Scotland.

AIMS: To estimate the prevalence of opiate or benzodiazepine misuse in the Grampian Health Board area, Scotland and illustrate the use of the capture-recapture method in both rural and urban settings. DESIGN: Capture-recapture analyses on six distinct sources of data with unequal coverage of the geographical area. SETTING: Grampian Health Board area, including the City of Aberdeen. PARTICIPANTS: Data were collated from the Police, Social Work Departments, GPs contributing to the Scottish Drug Misuse Database, statutory drug agencies, a voluntary sector drug agency and a needle/syringe exchange. MEASUREMENTS: In total 1770 individuals were identified as misusing opiates or benzodiazepines and residing in the Grampian Health Board area; 1129 individuals were resident in the City of Aberdeen. FINDINGS: The total number of opiate or benzodiazepine misusers in the City of Aberdeen was estimated to be 2519 (95% CI 2048-3200). This figure corresponds to 2.0% (1.6-2.5%) of the population aged 15-54 years. In a town to the north of Aberdeenshire where high levels of heroin use had previously been reported in the media, 2.5% of the population aged 15-54 (1.8-3.8%) were estimated to be misusing opiates or benzodiazepines. CONCLUSIONS: Although there may be difficulties in applying capture-recapture methods in all settings, the methodology can give valuable information on the extent of drug misuse in both urban and non-urban areas. This information is particularly important to assess the spread of drug misuse from cities to rural areas.

The attendance pattern of clients at a Scottish needle exchange.

AIMS: To examine the pattern of attendance at a Scottish needle exchange. DESIGN: Semi-structured interviews and retrospective analysis of attendance patterns. SETTING: A needle exchange in a Scottish city which covers the whole of the city. PARTICIPANTS: Clients and staff of the needle exchange. MEASUREMENTS: The attendance pattern of 1556 clients of the needle exchange over a 4-year period 1995-1998. FINDINGS: The average frequency of attendance over the 4-year period was 12.7. In 1998, 23% had only visited the needle exchange once and 11% had only visited twice. CONCLUSIONS: A significant minority of clients only attend the needle exchange once or twice a year. There is a need to include information on client retention in future evaluations of needle and syringe exchange clinics and to specify the kind of relationships needle and syringe exchange clinic staff are expected to develop with clients and what level of client retention they should be aiming towards in a well-run clinic.

Estimating the prevalence of drug misuse in Dundee, Scotland: an application of capture-recapture methods.

STUDY OBJECTIVES: To apply capture-recapture methods to provide an estimate of the prevalence of opiate and benzodiazepine misuse in Dundee, Scotland. DESIGN: A four sample capture-recapture method using data from both statutory and non-statutory data sources to estimate drug misuse prevalence in Dundee between January 1990 and December 1994. PARTICIPANTS: Users of benzodiazepines or opiates residing within Dundee. RESULTS: Altogether 855 drug misusers were identified from various sources within Dundee; many were identified from more than one source. Using this data, the estimated unknown population was 1702, giving a total population of 2557 (95% confidence interval (CI) 1974, 3458) who misuse benzodiazepines or opiates. This represents a prevalence of 28.8 (95% CI 22.3, 39.0) per thousand. CONCLUSIONS: Capture-recapture techniques can be applied to statutory and non-statutory agency data to produce an estimate of at least certain sections of the drug misusing population. However, it is important to recognise the limitations of this methodology and in future to seek to combine a range of approaches to the problem of estimating prevalence rather than sticking rigidly to any single approach.

A physical assessment of the imaging performance of panel-type X-ray image intensifier.

The performance of a commercial panel-type X-ray image intensifier has been investigated by physical methods, both objective and subjective. The objective measurements show that the manufacturer's claims are justified, except perhaps in regard to contrast loss. The subjective measurements reveal that the conversion factor ("gain") of the device is such that dark-adaptation is not necessary, though best results are obtained in a nearly dark room. Hence the device confers a significant advantage, both in information and in dose to the patient, over traditional fluoroscopy. However, the conversion factor is nearly three orders of magnitude smaller than that of a conventional X-ray image-intensifier television system. Therefore, at modern fluoroscopic exposure rates, the eye is operating at light levels at which its own deficiencies set a limit to the perceptible information. To equal the performance of modern fluoroscopy the exposure rate to the intensifier must be increased to about 20 times the value customary in modern fluoroscopy. This can be done only by increasing the X-ray factors (kV and mA), resulting in a corresponding increase in dose to the patient of about one order of magnitude. Such an increase is in many circumstance unacceptable.

A set of X-ray test objects for quality control in television fluoroscopy.

The history of performance testing in Leeds of television fluoroscopic systems is briefly outlined. Using the visual, physical and technological requirements as a basis, a set of nine test objects for quality control in television fluoroscopy is described. The factors measured by the test objects are listed in the introduction; the test objects and their function are fully described in the remainder of the paper. The test objects, in conjunction with a television oscilloscope, give both subjective and objective information about the X-ray system. Three of the test objects enable the physicist or engineer to adjust certain aspects of the performance of the X-ray system. The set of nine test objects is available commercially.

Synthesis and characterization of 6-O-beta-lactosyl-alpha,beta-lactoses, 1-O-(6-O-beta-lactosyl-beta-lactosyl)-(R,S)-glycerols, and 4,6-di-O-beta-D-galactopyranosyl-alpha,beta-D-glucoses.

1,2,3,2',3',4',6'-Hepta-O-acetyl-beta-lactose (4) was coupled with 2,3,6,2',3',4',6'-hepta-O-acetyl-alpha-lactosyl bromide (7) in the presence of Hg(CN)2 to afford 1,2,3,2',3',4',6'-hepta-O-acetyl-6-O-(2,3,6,2',3',4',6'-hepta-O-acetyl-b eta- lactosyl)-beta-lactose (11) which, upon O-deacetylation, gave 6-O-beta-lactosyl-alpha,beta-lactoses (64% from 4). In contrast, the reaction of 7 with benzyl 2,3,2',3',4',6'-hexa-O-acetyl-beta-lactoside in the presence of Hg(CN)2 produced 3,6,2',3',4',6'-hexa-O-acetyl-1,2-O- (2,3,2',3',4',6'-hexa-O-acetyl-1-O-benzyl-beta-lactos-6-yl orthoacetyl)-alpha-lactose (63%) and 3,6,2',3',4',6'-hexa-O-acetyl-1,2-O-(1- cyanoethylidene)-alpha-lactose (27%). The glycosidation of 4 using 2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranosyl bromide in the presence of Hg(CN)2 afforded, after deprotection, 4,6-di-O-beta-D-galactopyranosyl-alpha,beta-D-glucoses (66%). The reaction of 11 with 1,2-di-O-benzyl-(R,S)-glycerols and trimethylsilyl trifluoromethanesulfonate yielded, after deprotection, 1-O-(6-O-beta-lactosyl-beta-lactosyl)-(R,S)-glycerols (18%). Under the same coupling conditions 11 reacted with 2-O-benzylglycerol to form 3-O-acetyl-2-O-benzyl-1-O-[2',3',4',6'-hexa-O-acetyl-6-O-(2,3,6,2',3',4' ,6'- hepta-O-acetyl-beta-lactosyl)-beta-lactosyl]-(R,S)-glycerols (16%).

Synthesis and characterization of 2-O-beta-lactosylglycerol, 1,2-di-O-beta-lactosyl-(R,S)-glycerols, and 1,2,3,-tri-O-beta-lactosylglycerol.

The reaction of 2,3,6,2',3',4',6'-hepta-O-acetyl-alpha-lactosyl bromide (5) and 1,3-di-O-benzylglycerol in the presence of mercury(II) cyanide in benzene-nitromethane afforded 1,3-di-O-benzyl-2-O-(2,3,6,2',3',4',6'-hepta-O-acetyl-beta-lactosyl)glyc erol (70%), which was converted into 2-O-beta-lactosylglycerol. 1,2-Di-O-beta-lactosyl-(R,S)-glycerols were obtained by way of the coupling of 5 to either 1-O-benzyl-(R,S)-glycerol or 1-O-benzyl-2-O-(2,3,6,2',3',4',6'-hepta-O-acetyl-beta-lactosyl)-(R,S)-gl ycerols. The most efficient route to 1,2, 3-tri-O-beta-lactosylglycerol (17) involved treatment of 2-O-(2,3,6,2',3',4',6'-hepta-O-acetyl-beta-lactosyl)glycerol with 3 mol. equiv. of 5 followed by removal of the blocking groups, to give 17 (47%).

Binding of D-galactose-terminated ligands to rabbit asialoglycoprotein receptor.

The binding affinities of a series of D-galactose-terminated glycerol glycosides and oligosaccharides for the asialoglycoprotein receptor isolated from rabbit liver were determined in vitro using a radioreceptor-inhibition assay with 125I-asialoorosomucoid. The relative affinities of the synthetic ligands increased with the number of exposed D-galactose termini. Of the compounds examined, 1,2,3-tri-O-beta-lactosylglycerol associated with the greatest affinity (estimated Kd = 7.97 x 10(-5) M). Examination of the affinities of the synthetic series indicated that both the number and propinquity of the D-galactose termini influenced the strength of the binding interactions.

Synthesis and characterization of 6-O-beta-lactosyl-alpha,beta-D-mannopyranoses and 2,6-di-O-beta-lactosyl-alpha,beta-D-mannopyranoses.

The reaction of 2,3,6,2',3',4',6'-hepta-O-acetyl-alpha-lactosyl bromide (4) and benzyl 3,4-di-O-benzyl-alpha-D-mannopyranoside (3) in the presence of mercury(II) cyanide in benzene-nitromethane produced benzyl 3,4-di-O-benzyl-2,6-bis-O-(2,3,6,2',3',4',6'-hepta-O-acetyl-beta-lact osy l)-alph a D-mannopyranoside (5) and benzyl 3,4-di-O-benzyl-6-O-(2,3,6,2',3',4',6'-hepta-O-acetyl-beta-lactosyl)-alp ha-D- mannopyranoside (6), as part of a complex mixture. Column chromatography, followed by acetylation of the fraction containing 5 and 6, gave a sample of 5 and benzyl 2-O-acetyl-3,4-di-O-benzyl-6-O (2,3,6,2',3',4',6'-hepta-O-acetyl-beta-lactosyl)-alpha-D-mannopyranoside (7) in approximately 35% and 17% yields (based on 4), respectively. Deprotection of 5 and 7 afforded the target compounds, namely 2,6-di-O-beta-lactosyl-alpha,beta-D-mannopyranoses and 6-O-beta-lactosyl-alpha,beta-D-mannopyranoses, respectively. If the coupling of 4 with 3 were performed in the presence of silver trifluoromethanesulfonate and 2,4,6-trimethylpyridine, only a mixture of 3,6,2',3',4',6'-hexa-O-acetyl- alpha-lactose-1,2-[( 3,6,2',3',4',6'-hexa-O-acetyl-alpha-lactose 1,2-(benzyl 3,4-di-O-benzyl-alpha-D-mannopyranosid-6-yl orthoacetyl)-2-yl]orthoacetate) and 3,6,2',3',4',6'-hexa-O-acetyl-alpha-lactose 1,2-(benzyl 3,4-di-O-benzyl-alpha-D-mannopyranosid-6-yl orthoacetate) was obtained. The orthoacetates were characterized by n.m.r. spectroscopy. The two target materials are useful in the assessment of the binding properties of galactose-terminated ligands to the asialoglycoprotein receptor of normal rabbit and human hepatocytes.

Parotid lipomatosis.

A case of parotid lipomatosis is reported, and the literature is reviewed. This rare condition presents as a slow growing parotid mass, which may be diagnosed preoperatively using computed tomography or magnetic resonance imaging. Long-term clinical follow-up is important because apparently complete surgical excision may be complicated by recurrence.

Lateral subvastus approach with osteotomy of the tibial tubercle for total knee replacement: a two-year prospective, randomised, blinded controlled trial.

The lateral subvastus approach combined with an osteotomy of the tibial tubercle is a recognised, but rarely used approach for total knee replacement (TKR). A total of 32 patients undergoing primary TKR was randomised into two groups, in one of which the lateral subvastus approach combined with a tibial tubercle osteotomy and in the other the medial parapatellar approach were used. The patients were assessed radiologically and clinically using measurement of the range of movement, a visual analogue patient satisfaction score, the Western Ontario McMasters University Osteoarthritis Index and the American Knee Society score. Four patients were lost to the complete follow-up at two years. At two years there were no significant differences between the groups in any of the parameters for clinical outcome. In the lateral approach group there was one complication due to displacement of the tibial tubercle osteotomy and two osteotomies took more than six months to unite. In the medial approach group, one patient had a partial tear of the quadriceps. There was a significantly greater incidence of lateral patellar subluxation in the medial approach group (3 of 12) compared with the lateral approach group (0 of 16) (p = 0.034), but without any apparent clinical detriment. We conclude that the lateral approach with tibial tubercle osteotomy is a safe technique with an outcome comparable with that of the medial parapatellar approach for TKR, but the increased surgical time and its specific complications do not support its routine use. It would seem to be more appropriate to reserve this technique for patients in whom problems with patellar tracking are anticipated.