Computed tomography enteroclysis: a review

Computed tomography (CT) enteroclysis is being performed routinely for evaluation of suspected small bowel diseases. The availability of multidetector CT scanners has further increased the diagnostic yield of enteroclysis. There is excellent depiction of small bowel wall pathology on CT enteroclysis especially with use of negative enteric contrast. We discuss the CT enteroclysis technique and procedure along with the imaging spectrum of some common small bowel pathologies.     

Validation of the Clinical COPD Questionnaire as a psychophysical outcome measure in adult laryngotracheal stenosis

Objectives: To validate the Clinical Chronic Obstructive Pulmonary Disease Questionnaire (CCQ), a patient‐administered instrument developed for bronchopulmonary disease as a disease‐specific psychophysical outcome measure for adult laryngotracheal stenosis. Design: Prospective observational study. Settings: Tertiary/National referral airway reconstruction centre. Participants: Thirty‐three tracheostomy‐free patients undergoing endoscopic laryngotracheoplasty. Main outcome measures: CCQ and the Medical Research Council (MRC) Dyspnoea scale, a previously validated but more limited scale, were administered to patients 2 weeks before surgery, preoperatively, and 2 weeks after endoscopic laryngotracheoplasty. Pulmonary function was assessed preoperatively. Internal consistency was assessed with Cronbach α statistics and test–retest reliability was determined using intraclass correlation. Correlations between CCQ and MRC scale, and pulmonary function were used to assess convergent and divergent validity respectively. Instrument responsiveness was assessed by correlating total and domain‐specific CCQ scores with anatomical disease severity and post‐treatment effect size. Results: There were 12 males and 21 females. Mean age was 44 ± 15 years. Cronbach α coefficient and intraclass correlation coefficient were 0.88 and 0.95 respectively. Total and domain‐specific CCQ scores significantly correlated with the MRC scores (P < 0.001) and significant correlations between CCQ and peak expiratory flow rate and FEV₁ were identified (P < 0.03). There were statistically significant changes in total and domain‐specific CCQ scores when different stenosis severities were compared. Clinical COPD Questionnaire scores also changed significantly and congruently following surgery (P < 0.05 in both cases). Discussion: Clinical COPD Questionnaire is a valid and sensitive instrument for assessing symptom severity and levels of function and well‐being in adult patients with laryngotracheal stenosis and can be used as a patient‐centred disease‐specific outcome measure for this condition.     

Inhibition of TNF-α-induced Cyclooxygenase-2 Expression by Mycobacterium bovis BCG in Human Alveolar Epithelial A549 Cells

Cyclooxygenase-2 (COX-2) is implicated in pathophysiological processes associated with the initiation or maintenance of host inflammatory responses to infection. Our results demonstrates that Mycobacterium bovis BCG ( M. bovis BCG) downregulates tumour necrosis factor-α (TNF-α)-induced COX-2 gene expression in alveolar epithelial cells by inhibiting the phosphorylations of Raf-1 and p38 kinases. Further, M. bovis BCG-mediated inhibition of COX-2 or p38 mitogen-activated protein kinase could be reversed by Calyculin A, a selective inhibitor of Ser/Thr phosphatases. Moreover, M. bovis BCG inhibited the TNF-α-triggered NF-κB activation following IκB degradation. Taken together, these results suggest that the attenuation of COX-2 expression by vaccine strain, M. bovis BCG, represents a novel strategy to maintain robust host proinflammatory responses to subsequent challenges with virulent tuberculosis bacilli.     

Total bone mineral content and body composition by x-ray densitometry in newborns.

Measurement of total body bone mineral content and body composition has not previously been convenient in the newborn. X-ray densitometry, otherwise known as dual-energy x-ray absorptiometry (DEXA), has been used in adults to assess with accuracy and precision the total body mineral content, lean mass, and fat. Body composition measurements were determined in vivo by DEXA in term newborns, and they were compared with values reported by chemical analysis of the cadaver, with skin-fold thickness measurements, and with bone mineral content measured by single photon absorptiometry. The intermeasurement coefficient of variation was < or = 2.5% for bone mineral content, and < or = 1% for fat and lean mass. The values for bone mineral content, fat, and lean mass fall within the ranges expected based on the reported values measured by chemical analysis of the infant cadaver. Triceps and quadriceps skin-fold measurements were best correlated with total body fat as measured by DEXA. The bone mineral content of the distal third radius site as measured by single photon absorptiometry in newborns showed significant correlation with total body bone mineral content. DEXA provides a reproducible and convenient method for the determination of body composition in newborns.     

Early neonatal hypocalcemia in extremely preterm infants. High incidence, early onset, and refractoriness to supraphysiologic doses of calcitriol

Nineteen preterm infants born at or before 32 weeks of gestation were studied to determine the dose of calcitriol that would be effective in the prophylaxis of early neonatal hypocalcemia (serum calcium level, less than 7.0 mg/dL [less than 1.75 mmol/L]). In these infants the course of early neonatal hypocalcemia was not modified by calcitriol administration. Serum 1,25-dihydroxyvitamin D level rose in response to intramuscular administration of calcitriol. The incidence of hypocalcemia in these infants was 37% by 12 hours, 83% by 24 hours, and 89% by 36 hours. Thus, in extremely preterm infants, the incidence of early neonatal hypocalcemia is higher and the onset earlier than in larger preterm infants; furthermore, in these infants the hypocalcemia is refractory even to high doses of calcitriol.     

Utilization of PD modalities: evolution

In the early 1960s, peritoneal dialysis (PD) was introduced as a form of long-term maintenance therapy in patients with end-stage renal disease (ESRD). We have come a long way since. Increasing understanding of peritoneal kinetic behavior, its innovative manipulation to meet patient needs, critical monitoring of clinical outcomes, and parallel development in technology have all contributed to the worldwide success of the therapy over the past four decades. In this article we review the evolution of the various PD modalities in the context of these factors.     

Determination of tacrine metabolites in microsomal incubate by high performance liquid chromatography-nuclear magnetic resonance/mass spectrometry with a column trapping system

A column trapping system has been incorporated into high performance liquid chromatography-nuclear magnetic resonance-mass spectrometry (HPLC-NMR-MS) to reduce data acquisition time of NMR experiments. The system uses a trapping column to capture analytes after the HPLC column and back flush trapped analyte to the flow cell of the NMR probe for detection. A dilution solvent is mixed with eluent from HPLC column to reduce the influence of the organic content in the mobile phase before column trapping. The trapping column is also coupled with a mass spectrometer (MS) to get complementary MS data on the same peak. Studies on 1-hydroxylated 9-amino-1,2,3,4-tetrahydro-acridine (1-OH tacrine), indomethacin and testosterone with the column trapping system showed good recovery of analytes and over 3-fold mean increase in UV-VIS signal intensity. The time saving on NMR experiments with the column trapping system was demonstrated by the analysis of dog microsomal incubate with tacrine.     

Role of advanced 2 and 3-dimensional ultrasound for detecting prostate cancer

PURPOSE: We explored the clinical usefulness of spectrum analysis and neural networks for classifying prostate tissue and identifying prostate cancer in patients undergoing transrectal ultrasound for diagnostic or therapeutic reasons. MATERIALS AND METHODS: Data on a cohort of 215 patients who underwent transrectal ultrasound guided prostate biopsies at Memorial-Sloan Kettering Cancer Center, New York, New York were included in this study. Radio frequency data necessary for 2 and 3-dimensional (D) computer reconstruction of the prostate were digitally recorded at transrectal ultrasound and prostate biopsy. The data were spectrally processed and 2-D tissue typing images were generated based on a pre-trained neural network classification. We used manually masked 2-D tissue images as building blocks for generating 3-D tissue images and the images were tissue type color coded using custom software. Radio frequency data on the study cohort were analyzed for cancer probability using the data set pre-trained by neural network methods and compared with conventional B-mode imaging. ROC curves were generated for the 2 methods using biopsy results as the gold standard. RESULTS: The mean area under the ROC curve plus or minus SEM for detecting prostate cancer for the conventional B-mode and neural network methods was 0.66 +/- 0.03 and 0.80 +/- 0.05, respectively. Sensitivity and specificity for detecting prostate cancer by the neural network method were significantly increased compared with conventional B-mode imaging. In addition, the 2 and 3-D prostate images provided excellent visual identification of areas with a higher likelihood of cancer. CONCLUSIONS: Spectrum analysis could significantly improve the detection and evaluation of prostate cancer. Routine real-time application of spectrum analysis may significantly decrease the number of false-negative biopsies and improve the detection of prostate cancer at transrectal ultrasound guided prostate biopsy. It may also provide improved identification of prostate cancer foci during therapeutic intervention, such as brachytherapy, external beam radiotherapy or cryotherapy. In addition, 2 and 3-D images with prostate cancer foci specifically identified can help surgical planning and may in the distant future be an additional reliable noninvasive method of selecting patients for prostate biopsy.     

Tick paralysis in children: electrophysiology and possibility of misdiagnosis

The authors report six patients with tick paralysis seen over 5 years. Clinical and electrodiagnostic findings failed to adequately distinguish tick paralysis from Guillain-Barré syndrome in these patients. Finding a tick attached to the scalp or the nape of the neck and removing it resulted in rapid clinical improvement.     

Dietary copper enhances the peripheral myelinopathy produced by oral pyrrolidine dithiocarbamate.

The neurotoxic hazard of a dithiocarbamate is influenced by route of exposure and acid stability of the dithiocarbamate. As an example, oral administration of the acid labile dithiocarbamate N,N-diethyldithiocarbamate (DEDC) causes a central-peripheral axonopathy thought to result from acid-promoted decomposition to CS2 in the stomach. In contrast, parenteral administration of DEDC, which bypasses the acidic environment of the stomach, causes a primary demyelination that is thought to be mediated through the intact parent dithiocarbamate. The relative acid stability of pyrrolidine dithiocarbamate (PDTC) suggests that a significant portion of a dose can be absorbed intact following oral exposure with the potential to produce a primary myelin injury. The present study was performed to characterize the neurotoxicity of PDTC and evaluate the possible role of copper in dithiocarbamate-mediated demyelination. Male Sprague Dawley rats were administered PDTC in drinking water and given either a normal- or high-copper diet for 18, 47, or 58 weeks. Examination of peripheral nerve by light microscopy and electron microscopy at the end of exposures revealed primary myelin lesions and axonal degeneration in the PDTC groups, with a significant increase in the severity of several lesions observed for the PDTC, high-copper group relative to the PDTC normal-copper diet. ICP-AES metal analysis determined that the PDTC groups had significantly increased brain copper, and at 58 weeks a significant increase in copper was seen in the sciatic nerve of PDTC high-copper animals relative to PDTC normal-copper diet animals. Although RP-HPLC analysis could not detect globin alkylaminocarbonyl cysteine modifications analogous to those seen with parenteral DEDC, LC/MS/MS identified (pyrrolidin-1-yl carbonyl)cysteine adducts on PDTC-exposed rat globin. These findings are consistent with previous studies supporting the ability of acid-stable dithiocarbamates to mediate myelin injury following oral exposure. The greater severity of lesions associated with dietary copper supplementation and elevated copper levels in nerve also suggests that perturbation of copper homeostasis may contribute to the development of myelin lesions.