Correlations of nuclear magnetic resonance imaging, computerized tomography, and clinical profiles in multiple sclerosis

Nuclear magnetic resonance (NMR) imaging was superior to CT for imaging the brain lesions of 27 patients with MS. The incidence of abnormal examinations was 78% by NMR and 63% by CT. In cases in which both studies were abnormal, NMR usually demonstrated many more lesions and more extensive involvement than CT. The appearance and locations of lesions identified by NMR were similar to those of autopsy studies of MS and may be relatively specific for this disease. Some lesions identified by CT disappeared during serial examinations, but lesions identified by NMR did not resolve over time. Seventy-five percent of the lesions were clinically "silent"; only 5% were definitely related to the clinical symptoms and signs. All of those lesions were located in the brainstem or cerebellar peduncles and were identified by NMR, but missed by CT.     

Annexin A1 subcellular expression in laryngeal squamous cell carcinoma

Aims: Annexin A1 (ANXA1) is a soluble cytoplasmic protein, moving to membranes when calcium levels are elevated. ANXA1 has also been shown to move to the nucleus or outside the cells, depending on tyrosine‐kinase signalling, thus interfering in cytoskeletal organization and cell differentiation, mostly in inflammatory and neoplastic processes. The aim was to investigate subcellular patterns of immunohistochemical expression of ANXA1 in neoplastic and non‐neoplastic samples from patients with laryngeal squamous cell carcinomas (LSCC), to elucidate the role of ANXA1 in laryngeal carcinogenesis. Methods and results: Serial analysis of gene expression experiments detected reduced expression of ANXA1 gene in LSCC compared with the corresponding non‐neoplastic margins. Quantitative polymerase chain reaction confirmed ANXA1 low expression in 15 LSCC and eight matched normal samples. Thus, we investigated subcellular patterns of immunohistochemical expression of ANXA1 in 241 paraffin‐embedded samples from 95 patients with LSCC. The results showed ANXA1 down‐regulation in dysplastic, tumourous and metastatic lesions and provided evidence for the progressive migration of ANXA1 from the nucleus towards the membrane during laryngeal tumorigenesis. Conclusions: ANXA1 dysregulation was observed early in laryngeal carcinogenesis, in intra‐epithelial neoplasms; it was not found related to prognostic parameters, such as nodal metastases.     

Induction of short gut syndrome and transplantation in a porcine model

Experimental models in small animals have been described for nutritional studies after small bowel transplantation for extensive resection. Herein, we compared the outcome of transplanted pigs that underwent transplantation after total small bowel resection (SBR) with controls without transplantation. METHODS: Twenty-one Landrace pigs (mean weight 30 kg) were assigned to 1 of 3 groups: group 1 (n = 6) underwent 80% SBR; group 2 (n = 9), total bowel resection; and group 3 (n = 6) total resection plus small bowel transplantation. Postoperative evaluation included biochemical analyses, weights, and evaluation of clinical status. Conventional endoscopies with graft biopsies were obtained every 4 days to assess rejection. RESULTS: Group 1 showed increased body weight after 3 weeks due to bowel adaptation, whereas groups 2 and 3 lost weight, an observation that correlated with biochemical analyses. Median survival in group 3 was 10 +/- 2 days; all hosts died of sepsis related to severe acute rejection. DISCUSSION: Short gut syndrome appeared in group 2 but not in group 1, where intestinal adaptation was observed by 4 weeks after the resection. Rejection was confirmed in group 3 using conventional endoscopy plus biopsies and at necropsy. CONCLUSION: Total bowel resection is an adequate model for short gut syndrome in pigs, rejection can be readily identified by using conventional endoscopy.     

Magnetic Resonance Angiography in Glomus Arteriovenous Malformation of the Cervical Spine

Conventional magnetic resonance imaging (MRI) and spine magnetic resonance angiography (MRA) demonstrated a glomus-type intradural arteriovenous malformation of the upper cervical region of the spine in a 24-year-old woman. Gadolinium-enhanced, three-dimensional, phase-contrast angiography displayed the nidus and feeders of the arteriovenous malformation. The clinical features of the two most common types of spinal arteriovenous malformations (dural arteriovenous fistula and glomus intradural arteriovenous malformation) are reviewed. Conventional MRI and spine MRA may obviate the need for performing total spinal myelography in patients suspected of having spinal arteriovenous malformations.     

Subcortical arteriosclerotic encephalopathy (Binswanger's disease). Computed tomographic, nuclear magnetic resonance, and clinical correlations

Twenty-three elderly patients were found to have a consistent pattern of leukoencephalopathy by computed tomography and nuclear magnetic resonance imaging. Eight patients presented with vague, nonspecific symptoms and had no neurologic deficits. The other 15 patients had neurologic deficits that presented in one of three ways: stroke, seven patients; slowly progressive dementia and gait disturbance, five patients; or slowly progressive dementia alone, three patients. Risk factors for arteriosclerosis (hypertension, diabetes) were present in 18 patients (78%). The necropsy of one patient revealed arteriosclerotic vasculopathy characteristic of subcortical arteriosclerotic encephalopathy (SAE) or Binswanger's disease. Subcortical arteriosclerotic encephalopathy may be a relatively common affliction of elderly patients, most of whom have risk factors for arteriosclerosis. The modes of presentation and associated clinical signs are variable, and more than one third may have no neurologic deficit. In some cases SAE overlaps with normal pressure hydrocephalus by clinical and neuroimaging criteria. Some patients with normal pressure hydrocephalus who do not respond to ventricular shunting may actually have SAE.     

Primary screening of blood donors by nat testing for HCV-RNA: development of an "in-house" method and results

An "in-house" RT-PCR method was developed that allows the simultaneous detection of the RNA of the Hepatitis C Virus (HCV) and an artificial RNA employed as an external control. Samples were analyzed in pools of 6-12 donations, each donation included in two pools, one horizontal and one vertical, permitting the immediate identification of a reactive donation, obviating the need for pool dismembering. The whole process took 6-8 hours per day and results were issued in parallel to serology. The method was shown to detect all six HCV genotypes and a sensitivity of 500 IU/mL was achieved (95% hit rate). Until July 2005, 139,678 donations were tested and 315 (0.23%) were found reactive for HCV-RNA. Except for five false-positives, all 310 presented the corresponding antibody as well, so the yield of NAT-only donations was zero, presenting a specificity of 99.83%. Detection of a window period donation, in the population studied, will probably demand testing of a larger number of donations. International experience is showing a rate of 1:200,000 - 1:500,000 of isolated HCV-RNA reactive donations.     

Replacement of HIV p24 Ag test by a multiplex RT-PCR method for primary screening of blood donors

Nucleic Acid Testing (NAT) as a tool for primary screening of blood donors became a reality in the end of the 1990 decade. We report here the development of an "in-house" RT-PCR method that allows the simultaneous (multiplex) detection of HCV and HIV-RNA in addition to an artificial RNA employed as an external control. This method detects all HIV group M subtypes, plus group N and O, with a detection threshold of 500 IU/mL. After validation, the method replaced p24 Ag testing, in use for blood donation screening since 1996 at our services. From July 2001 to February 2006, 102,469 donations were tested and 41 (0.04%) were found HIV-RNA reactive. One NAT-only reactive donation (antibody non-reactive) was observed, with subsequent seroconversion of the implied donor, giving a yield of 1:102,469. This rate is in contrast to the international experience that reports a detection of approximately 1:600,000 - 1:3,100,000 of isolated HIV-RNA donations.     

Prospective, randomized trial comparing fluids and dobutamine optimization of oxygen delivery in high-risk surgical patients [ISRCTN42445141]

Introduction

Preventing perioperative tissue oxygen debt contributes to a better postoperative recovery. Whether the beneficial effects of fluids and inotropes during optimization of the oxygen delivery index (DO₂I) in high-risk patients submitted to major surgeries are due to fluids, to inotropes, or to the combination of the two is not known. We aimed to investigate the effect of DO₂I optimization with fluids or with fluids and dobutamine on the 60-day hospital mortality and incidence of complications.

Methods

A randomized and controlled trial was performed in 50 high-risk patients (elderly with coexistent pathologies) undergoing major elective surgery. Therapy consisted of pulmonary artery catheter-guided hemodynamic optimization during the operation and 24 hours postoperatively using either fluids alone (n = 25) or fluids and dobutamine (n = 25), aiming to achieve supranormal values (DO₂I > 600 ml/minute/m²).

Results

The cardiovascular depression was an important component in the perioperative period in this group of patients. Cardiovascular complications in the postoperative period occurred significantly more frequently in the volume group (13/25, 52%) than in the dobutamine group (4/25, 16%) (relative risk, 3.25; 95% confidence interval, 1.22–8.60; P < 0.05). The 60-day mortality rates were 28% in the volume group and 8% in the dobutamine group (relative risk, 3.00; 95% confidence interval, 0.67–13.46; not significant).

Conclusion

In patients with high risk of perioperative death, pulmonary artery catheter-guided hemodynamic optimization using dobutamine determines better outcomes, whereas fluids alone increase the incidence of postoperative complications.