[Tuberculosis cutis colliquativa. Even today an important differential diagnosis]. / Tuberculosis cutis colliquativa. Auch heute eine wichtige Differenzialdiagnose.

An 82-year-old woman presented with perforating abscesses in the cervical and axillary region over 7 months. Histopathological and extensive microbiological examinations lead to the diagnosis of tuberculosis cutis colliquativa, a form of postprimary cutaneous tuberculosis. Tuberculosis cutis colliquativa can be caused by either contiguous spread from an underlying structure, direct inoculation or hematogenous dissemination. Morphologically it is characterized by a subcutaneous node forming an abscess with secondary perforation of overlying skin. The parotid, submandibular, and supraclavicular regions are the sites most likely to be affected. Today it still remains an important differential diagnosis for an abscess with fistulas. Correlation with histopathologic findings and microbiological examinations including polymerase chain reaction and mycobacterial culture being the most reliable method is required. Standard therapy regimens consist of 2 months of quadruple therapy followed by another 4 months of a continuation phase using a two-drug regimen.

[Tuberous sclerosis: diagnostic criteria and new treatment approaches]. / Tuberöse Sklerose : Diagnosekriterien und neue Therapieansätze.

With a prevalence of 1 in 6,000 births, tuberous sclerosis is a relatively frequent hamartoma and tumor syndrome inherited as an autosomal dominant trait, which manifests primarily on the skin and in the central nervous system. Decisive factors for morbidity and mortality and thus for the prognosis are the changes in the central nervous system in the form of cortical hamartomas. Treatment for many years consisted solely in using nonspecific symptomatic approaches; dermatological therapy comprised mainly laser or electroacoustic ablation of facial angiofibromas. New models of therapy hinder the pathogenesis of tuberous sclerosis. Various studies provided evidence that the macrolide rapamycin decreases growth of brain and kidney tumors by specific inhibition of mTOR kinase. Synergistic effects were observed in combination therapy with the cytokine IFN-gamma.

Registry of experimental cancers of the National Cancer Institute.

This report describes the organization and functions of the Registry of Experimental Cancers and gives the chronology of events that led to its establishment. Currently 21,500 accessions have been coded; the vast majority are spontaneous and induced cancers, chiefly of rodents, and also a wide variety of nonneoplastic diseases. Accessions are accepted from contributors working in laboratories in this country and abroad. The material is available for study by responsible scientists, and a limited number of study sets is available for loan on request.

Overt signs of toxicity to dogs and cats of dietary deoxynivalenol.

Studies were conducted to determine the dietary amounts of deoxynivalenol (DON; vomitoxin) in dog and cat food that are required to produce overt signs of toxicity (e.g., vomiting or reduced food intake). Wheat naturally contaminated with 37 mg of DON/kg was used to manufacture pet foods containing 0, 1, 2, 4, 6, 8, and 10 mg of DON/kg. Deoxynivalenol concentration in pet food following manufacture was unchanged, indicating that the toxin was stable during conventional extrusion processing. Dogs previously fed DON-contaminated food were able to preferentially select uncontaminated food. Dogs not previously exposed to DON-contaminated food consumed equal quantities of contaminated and uncontaminated food. There was no effect of 6 mg of DON/kg on dog food digestibility. Food intake of dogs was significantly reduced by DON concentrations greater than 4.5 +/- 1.7 mg/kg, and DON greater than 7.7 +/- 1.1 mg/kg reduced cat food intake. Vomiting by dogs and cats was commonly observed at the 8 and 10 mg DON levels.

Determination of retigabine and its acetyl metabolite in biological matrices by on-line solid-phase extraction (column switching) liquid chromatography with tandem mass spectrometry.

A HPLC assay with tandem mass spectrometric detection in the positive-ion atmospheric pressure chemical ionisation (APCI) mode for the sensitive determination of retigabine [(I), D-23129] and its acetyl metabolite [(II), ADW 21-360] in plasma was developed, utilising the structural analogue (D-10328), (III), as internal standard. Automated on-line solid-phase extraction of diluted plasma samples, based on 200-microl plasma aliquots, at pH 6.5, allowed a reliable quantification of retigabine and the acetyl metabolite down to 1 ng/ml. Injection of 500 microl of diluted plasma onto a C2 stationary phase-based column switching system in combination with a 75 mm x 4 mm reversed-phase analytical column at a flow-rate of 0.5 ml/min provided cycle times of 4 min per sample. The standard curves were linear from 1 to 1000 ng/ml using weighted linear regression analysis (1/x2). The method is accurate (mean accuracy < or = +/- 10%), precise (RSD < +/- 15%) and sensitive, providing lower limits of quantification in plasma of 1 ng/ml for retigabine (I), and 2.5 ng/ml for the metabolite (II) with limits of detection of 0.5 ng/ml for both analytes. Up to 200 unknowns may be analysed each 24 h per analyst.

[Measurement of gravity line position 15-25 years after Harrington-spondylodesis in adolescent idiopathic scoliosis]. / Untersuchungen zum Schwerpunktlot 15-25 Jahre nach Harrington-Distraktionsspondylodese bei Patienten mit idiopathischer Adoleszentenskoliose.

AIM: A prospective analysis was performed to evaluate the relation between sagittal spinal morphology, gravity line position and morphological parameters of the pelvis and lumbar spine. METHOD: 25 patients with a mean follow-up of 23 (15-37) years after thoracic Harrington distraction spondylodesis were included. Standing lateral full spine radiographs were performed while patients were standing on a force plate. Pelvic angles according to Duval-Beaupere were measured. RESULTS: Pelvic incidence varied from 30 degrees to 76 degrees (mean 52.1 degrees + 12.5 degrees ). Mean sacral slope was 36.4 degrees (+ 7.8 degrees ). The average thoracic kyphosis (23.6 degrees + 14.3 degrees ) and lumbar lordosis (36.4 degrees + 9.2 degrees ) were diminished. The gravity line position was on average 10.9 mm (+ 21.6mm) posterior to the center of the femoral heads. CONCLUSION: Our method quantifies the relationship between the gravity line position and pelvic parameters according to Duval-Beaupere. The homogenous study group of patients with AIS after Harrington spondylodesis is characterized by decreased lumbar and thoracic profile and posterior displacement of the gravity line position.

Electrokinetic chromatography using thermodynamically stable vesicles and mixed micelles formed from oppositely charged surfactants.

The electrokinetic chromatography (EKC) of a novel mixed surfactant system consisting of oppositely charged surfactants, sodium dodecyl sulfate (SDS) and n-dodecyltrimethylammonium bromide (DTAB), was investigated. The chromatographic characteristics of large liposome-like spontaneous vesicles and rodlike mixed micelles formed from the mixture were explored and compared with those of SDS micelles. Separations of a series of n-alkylphenones showed that the spontaneous vesicles provided about a 2 times wider elution window than SDS micelles. Both vesicle and mixed micelle systems were found to provide larger methylene selectivity than SDS. The different elution order of a group of nitrotoluene geometric isomers with DTAB/SDS spontaneous vesicles and SDS micelles pseudostationary phases suggested the possibility of different separation mechanisms with these two systems. Comparisons of polar group selectivity, retention, and efficiency were made between vesicles, mixed micelles, and SDS micelles. The correlation between the logarithms of the retention factors (log k') and octanol-water partition coefficients (log P(ow)) for a group of 20 neutral compounds was also studied with DTAB/SDS vesicles. Spontaneous vesicles have great potential as a pseudostationary phase in electrokinetic chromatography.

Predicting peak shape in capillary zone electrophoresis: a generic approach to parametrizing peaks using the Haarhoff-Van der Linde (HVL) function.

We have found that the Haarhoff-Van der Linde (HVL) peak function provides excellent fitting to the shapes of CZE peaks. Initially designed for overloaded peaks in gas chromatography, this function describes a Gaussian peak when there is no peak distortion, and a triangular peak when there is no diffusional peak broadening. As such, it is ideal for CZE peaks distorted by electromigration dispersion (EMD). Fitting peaks with this function gives four parameters: three of them can be related to the Gaussian peak that would have been obtained in case of no EMD; the last one is a measure of the peak distortion. Using moving boundary theory, this peak distortion parameter may readily be expressed in terms of analyte and background electrolyte mobilities and concentrations, electric field, and sample injection length. The variance of an HVL peak is shown to be described by a universal function, and a master equation is presented. The region where EMD adds less than 10% to the Gaussian variance is shown to be very narrowly spread around the mobility matching condition. Under typical CZE operating conditions with an analyte at 1% of the BGE concentration, significant peak distortion is always present. Because the total peak variance is not an addition of the Gaussian and triangular contributions, the HVL model and the methodology introduced here should always be used to correctly combine variances.

Quantification of perifosine, an alkylphosphocholine anti-tumour agent, in plasma by pneumatically assisted electrospray tandem mass spectrometry coupled with high-performance liquid chromatography.

An HPLC assay with tandem mass spectrometric detection in the positive-ion Turbo-Ion-Spray (TISP) mode for the fast and sensitive determination of perifosine ((I), D-21266) in human plasma was developed, utilising the structural analogue, miltefosine ((II), D-18506), as internal standard. Automated solid-phase extraction of diluted plasma samples, based on 250-microl plasma aliquots, at pH 6.5, allowed a reliable quantification of perifosine down to 4 ng/ml. Injection of 200 microl of plasma extracts onto a 100x3 mm normal-phase analytical column at a flow-rate of 0.5 ml/min provided retention-times of 2.4 and 2.1 min for perifosine (I) and the internal standard (II), respectively. The standard curves were linear from 4 to 2000 ng/ml using weighted linear regression analysis (1/Y2). The inter-assay and intra-assay accuracies for the calibration standards were within +0.9% and -0.2%, exhibiting precisions (C.V.) of +/-6.5 and +/-7.3%, respectively. Up to 100 unknowns may be analysed each 24 h per analyst.

Enantioselective high-performance liquid chromatography assay of (+)R- and (-)S-alpha-lipoic acid in human plasma.

A specific plasma level assay for the enantiomers of alpha-lipoic acid is described. It makes use of liquid-liquid extraction, chemical reduction to the dithiol enantiomers, and their precolumn chiral derivatisation with o-phthalaldehyde in the presence of D-phenylalanine. The two diastereomeric derivatives are separated by reversed-phase HPLC with fluorescence detection. The working range of the assay is between 15 ng/ml (lower limit of quantitation) and 1,000 ng/ml for either enantiomer.