Normative dimensions and symmetry of the lacrimal drainage system on dacryocystography: statistical analysis of morphometric characteristics.

BACKGROUND: Asymmetric lacrimal flow occurs in females more than males. We hypothesised that the normal lacrimal drainage system (LDS) may show subtle left-right asymmetry in morphometry when imaged on dacryocystography (DCG). MATERIALS AND METHODS: We retrospectively reviewed 60 normal bilateral LDSs.Images were analysed for 7 parameters: (1) combined length of either the superior or inferior canaliculus plus common canaliculus, (2) angle of insertion of common canaliculus into lacrimal sac (LS), (3, 4) length and width of the LS, (5) length of the naso lacrimal duct (NLD), and (6, 7) width of proximal and distal NLD. We tested the effect of independent variables (age, gender, and side) on each dependent variable (length, width, or angle) using regression analysis. We used a Studentt-test for independent samples to statistically compare bilateral LDSs. RESULTS: Patient median age was 62 years, and male:female ratio was 27:73. Mean dimensions and angles for all LDSs were: (1) 14.5 mm, (2) 57°,(3) 11.6 mm, (4) 2.1 mm, (5) 20.7 mm, (6) 1.4 mm, and (7) 1.8 mm. No independent variable affected variation in length, width, or angle. No significant difference emerged between dimensions of right and left LDSs in both sexes. CONCLUSIONS: A degree of affective lateralisation in the brain is known to result in lacrimal flow asymmetry after mood manipulation. We show that this is not reflected in LDS anatomy. Moreover, our detailed morphometric data can aid in therapeutic planning of LDS luminal procedures, especially when DCG images of one LDS are used as a road map for contralateral interventions.

The role of salivary duct morphology in the aetiology of sialadenitis: statistical analysis of sialographic features.

Morphologic characteristics of salivary ducts may contribute to stagnation of saliva. The authors hypothesized that some features might contribute to development of submandibular and parotid sialadenitis. 106 digital subtraction sialograms (DSS) were retrospectively reviewed for: degree of sialadenitis, length of Wharton's and Stensen's ducts (SD), and angle of Wharton's duct (WD) genu. Student's t test was used for independent samples to statistically compare normal and sialadenitis groups. The effect of independent variables (age, gender, side, degree of sialadenitis) on the dependent variable (length or angle) were tested using regression analysis. Submandibular duct sialadenitis was mild (67%), moderate (8%), or severe (25%); parotid duct sialadenitis was mild (57%), moderate (18%), or severe (25%). Mean length of normal WD was 58.2 mm, and 56.3 mm with sialadenitis. Mean length of normal SD was 52 mm, and 53 mm with sialadenitis. The mean angle of WD genu was 115° in normal ducts, and 119° with sialadenitis. None of the independent variables affected variation in length or angle. There were no statistical differences in duct length or measured angle between normal and sialadenitis groups. There is a wide variation in salivary duct morphology but this does not appear to be associated with the cause of sialadenitis.

Pathological diagnosis of variant Creutzfeldt-Jakob disease.

The neuropathological and biochemical features of the 89 histologically confirmed cases of variant Creutzfeldt-Jakob disease (vCJD) diagnosed up to the end of October 2001 in the UK are reviewed. Histology of the central nervous system, lymphoid tissues and other organs was accompanied by immunocytochemistry and Western blot analysis of the disease-associated form of the prion protein (PrP(RES)). All patients with vCJD were methionine homozygotes at codon 129 of the PrP gene. The pathology of vCJD showed relatively uniform morphological and immunocytochemical characteristics, which were distinct from other forms of CJD. PrP(RES) accumulation was widespread in lymphoid tissues in vCJD, but was not identified in other non-neural tissues. PrP(RES) in vCJD brain tissue showed a uniform glycotype pattern distinct from sporadic CJD. Given the increasingly widespread occurrence of bovine spongiform encephalopathy in Europe and Asia, there is a major need for widespread CJD surveillance. This should be accompanied by a multidisciplinary laboratory approach to the investigation and diagnosis of all forms of CJD, with the need to investigate autopsy tissues from suspected cases by the histological and biochemical techniques described herein.

A novel toxicity fingerprinting method for pollutant identification with lux-marked biosensors.

A novel technique is described for the identification and quantification of environmental pollutants based on toxicity fingerprinting with a metabolic lux-marked bacterial biosensor. This method involved characterizing the toxicity-based responses of the biosensor to seven calibration pollutants as acute temporal-dose response fingerprints. An algorithm is described to allow comparisons of responses of an unknown pollutant to be made against the calibration data. This is based on predicting pollutant concentration at each of six different time points over the course of a 5-min assay. If the prediction is consistent between the unknown pollutant and a calibration pollutant at the 95% test level, this is considered to be a positive identification. All seven calibration pollutants could be successfully distinguished from each other with this technique. Environmental samples, individually spiked with single concentrations of pollutants, were compared in this way against the calibration pollutants. An 83% identification success was achieved, with no false positives at the 95% test level. This is a simple and rapid technique that potentially can be applied to monitoring of industrial wastewater or as a screening tool for regulators.

Construction of a modified mini-Tn5 luxCDABE transposon for the development of bacterial biosensors for ecotoxicity testing.

A mini-Tn5 transposon was modified to introduce a promoterless luxCDABE cassette from Vibrio fischeri into environmentally relevant bacterial strains in order to develop bioluminescence-based biosensors for toxicity testing. The mini-Tn5 luxCDABE transposon was chromosomally integrated downstream from an active promoter into two Pseudomonas strains (Pseudomonas fluorescens 8866 and Pseudomonas putida F1). Characterisation of the bioluminescent transconjugants demonstrated that the transposon integration was stable and had no effect on growth rate. Both P. fluorescens 8866 Tn5 luxCDABE and P. putida F1 Tn5 luxCDABE were used to assess the toxicity of standard solutions (Cu, Zn and 3,5-DCP) as well as Cu- and 3,5-DCP-spiked groundwater samples. They were successfully used for bioluminescence-based bioassays and the potential value of using different bacterial biosensors for ecotoxicity testing was shown.

Bilateral and recurrent obturator hernia.

Obturator hernia is a rare condition which was first described in 1722 by de Ronsil. It occurs most commonly in elderly women who have lost weight and may strangulate in 25-100% of cases. Strangulated obturator hernia has a mortality as high as 10-50%, which is partly due to delay in diagnosis. A patient who developed three obturator hernias is described.

Management of obstructed balloon catheters.

Failure of a balloon catheter to deflate is not uncommon and prevents its removal. Methods of overcoming the problem include traction, bursting the balloon by overinflation, dissolving it with solvents, puncturing it percutaneously with a needle, or puncturing it with a wire stylet passed through the catheter. All except the last technique have major disadvantages and are of questionable safety. Transcatheter puncture of the balloon was used in 16 patients to remove obstructed balloon catheters without any technical difficulty, distress to the patient, or complication. The procedure is safe, simple, and does not require an anaesthetic. If necessary it could be performed safely by nursing or paramedical staff without the patient having to be admitted to hospital. It is the method of choice for the management of this problem.