Pulmonary pathological features in coronavirus associated severe acute respiratory syndrome (SARS)

BACKGROUND: Severe acute respiratory syndrome (SARS) became a worldwide outbreak with a mortality of 9.2%. This new human emergent infectious disease is dominated by severe lower respiratory illness and is aetiologically linked to a new coronavirus (SARS-CoV). METHODS: Pulmonary pathology and clinical correlates were investigated in seven patients who died of SARS in whom there was a strong epidemiological link. Investigations include a review of clinical features, morphological assessment, histochemical and immunohistochemical stainings, ultrastructural study, and virological investigations in postmortem tissue. RESULTS: Positive viral culture for coronavirus was detected in most premortem nasopharyngeal aspirate specimens (five of six) and postmortem lung tissues (two of seven). Viral particles, consistent with coronavirus, could be detected in lung pneumocytes in most of the patients. These features suggested that pneumocytes are probably the primary target of infection. The pathological features were dominated by diffuse alveolar damage, with the presence of multinucleated pneumocytes. Fibrogranulation tissue proliferation in small airways and airspaces (bronchiolitis obliterans organising pneumonia-like lesions) in subpleural locations was also seen in some patients. CONCLUSIONS: Viable SARS-CoV could be isolated from postmortem tissues. Postmortem examination allows tissue to be sampled for virological investigations and ultrastructural examination, and when coupled with the appropriate lung morphological changes, is valuable to confirm the diagnosis of SARS-CoV, particularly in clinically unapparent or suspicious but unconfirmed cases.     

Contributions of dynamic phosphorus-31 magnetic resonance spectroscopy to the analysis of muscle fiber distribution

RATIONALE AND OBJECTIVES: In high-performance athletes, conclusions regarding the muscle fiber distribution were to be drawn from dynamic 31phosphorus magnetic resonance spectroscopy (31P MRS). METHODS: Eleven volleyball players (V), eight bodybuilders (B), and 22 nonathletic volunteers (N) were examined by dynamic 31P MRS. During rest, exhaustive exercise, and recovery, respectively, up to 60 consecutive phosphorus spectra of the quadriceps muscle were acquired by "time series" in 36 s each. Two main spectroscopic approaches to the spectroscopic analysis of muscle fiber distribution were applied: evaluation of the ratio Pi/PCr at rest and the computer-assisted analysis of the Pi-peak at its exercise-induced line width maximum. RESULTS: At rest, the bodybuilders showed a significant lower Pi/PCr (0.07 +/- 0.03), in comparison with the volleyball players (0.11 +/- 0.03) and the nonathletic volunteers (0.11 +/- 0.02). The computer-assisted analysis of the Pi-peak at its line width maximum revealed a significantly lower pH of both of the subpeaks in the bodybuilders [6.30 versus 6.37 (V) and 6.38 (N); 6.89 versus 6.92 (V, N)], whereas the volleyball players provided the largest proportion of oxidative muscle fibers (68%), compared to bodybuilders (64%) and nonathletic volunteers (59%). A correlation between the ratio Pi/PCr and the area of the subpeak with the high pH (representing oxidative fibers) could not be demonstrated. CONCLUSIONS: Spectroscopic results during rest and exercise may be influenced by the muscle fiber distribution of the respective volunteer. The applied spectroscopic approaches to the analysis of muscle fiber composition are not compatible with each other; depending on the applied method, the classification of a muscle fiber as type I or type II fiber may change. The influence of physiologic factors like muscle fiber distribution on spectroscopic results has to be considered in the interpretation of pathological conditions.     

Depiction of anomalous coronary vessels and their relation to the great arteries by magnetic resonance angiography

Three-dimensional respiratory-gated coronary MR angiography (MRA) allowed accurate analysis of the anatomy of the coronary arteries and their relation to the adjacent anatomic structures in two patients with anomalous origin and proximal course of the coronary vessels. Together with functional tests, it decisively influenced further therapy. Received: 16 November 1999; Revised: 4 April 2000; Accepted: 3 May 2000     

Factors predicting progression of gastric intestinal metaplasia: results of a randomised trial on Helicobacter pylori eradication

BACKGROUND AND AIMS: Gastric intestinal metaplasia (IM) is generally considered to be a precancerous lesion in the gastric carcinogenesis cascade. This study identified the risk factors associated with progression of IM in a randomised control study. SUBJECTS AND METHODS: A total of 587 Helicobacter pylori infected subjects were randomised to receive a one week course of anti-Helicobacter therapy (omeprazole, amoxicillin, and clarithromycin (OAC)) or placebo. Subjects underwent endoscopy with biopsy at baseline and at five years. Severity of IM was graded according to the updated Sydney classification and progression was defined as worsening of IM scores at five years in either the antrum or corpus, or development of neoplasia. Backward stepwise multiple logistic regression was used to identify independent risk factors associated with IM progression. RESULTS: Of 435 subjects (220 in the OAC and 215 in the placebo group) available for analysis, 10 developed gastric cancer and three had dysplasia. Overall progression of IM was noted in 52.9% of subjects. Univariate analysis showed that persistent H pylori infection, age >45 years, male subjects, alcohol use, and drinking water from a well were significantly associated with IM progression. Duodenal ulcer and OAC treatment were associated with a reduced risk of histological progression. Progression of IM was more frequent in those with more extensive and more severe IM at baseline. With multiple logistic regression, duodenal ulcer (odds ratio (OR) 0.23 (95% confidence interval (CI) 0.09-0.58)) was found to be an independent protective factor against IM progression. Conversely, persistent H pylori infection (OR 2.13 (95% CI 1.41-3.24)), age >45 years (OR 1.92 (95% CI 1.18-3.11)), alcohol use (OR 1.67 (95% CI 1.07-2.62)), and drinking water from a well (OR 1.74 (95% CI 1.13-2.67)) were independent risk factors associated with IM progression. CONCLUSION: Eradication of H pylori is protective against progression of premalignant gastric lesions.     

Driving ability with vestibulär lesions

Bedingt durch die immer noch zunehmende Motorisierung der Bev?lkerung stellt sich in der Praxis des niedergelassenen HNO-Arztes vermehrt die Frage nach der Fahrtüchtigkeit eines Patienten, der einen Ausfall eines Vestibularapparates oder eine andere vestibul?re St?rung erlitten hat. Besonders problematisch ist es,wenn der Patient selbst subjektiv beschwerdefrei ist, eine L?sion aber noch nachweisbar ist, oder der Patient noch über Beschwerden klagt, obwohl eine vestibul?re St?rung nicht mehr objektivierbar ist. Im Folgenden wird der Versuch unternommen,einer L?sung dieser Probleme unter Berücksichtigung bekannter Mechanismen der Erholungsvorg?nge im vestibul?ren System und durch Darstellung der notwendigen Untersuchungsmethoden sowie exakter Definitionen der einzelnen Krankheitsbilder und ihrer Verl?ufe nahezukommen. Prof.Dr.Dr. K.-F.Hamann Universit?ts-HNO-Klinik der TU München, Ismaninger Stra?e 22,81675 München     

Treatment of experimentally induced transient cerebral ischemia with low energy laser inhibits nitric oxide synthase activity and up-regulates the expression of transforming growth factor-beta 1

BACKGROUND AND OBJECTIVES: Nitric oxide (NO) has been shown to be neurotoxic while transforming growth factor-beta 1 (TGF-beta1) is neuroprotective in the stroke model. The present study investigates the effects of low energy laser on nitric oxide synthase (NOS) and TGF-beta1 activities after cerebral ischemia and reperfusion injury. STUDY DESIGN/MATERIALS AND METHODS: Cerebral ischemia was induced for 1 hour in male adult Sprague-Dawley (S.D.) rats with unilateral occlusion of middle cerebral artery (MCAO). Low energy laser irradiation was then applied to the cerebrum at different durations (1, 5, or 10 minutes). The activity of NOS and the expression of TGF-beta1 were evaluated in groups with different durations of laser irradiation. RESULTS: After ischemia, the activity of NOS was gradually increased from day 3, became significantly higher from day 4 to 6 (P < 0.001), but returned to the normal level after day 7. The activity and expression of the three isoforms of NOS were significantly suppressed (P < 0.001) to different extents after laser irradiation. In addition, laser irradiation was shown to trigger the expression of TGF-beta1 (P < 0.001). CONCLUSIONS: Low energy laser could suppress the activity of NOS and up-regulate the expression of TGF-beta1 after stroke in rats.     

Local staging of rectal carcinoma and assessment of the circumferential resection margin with high-resolution MRI using an integrated parallel acquisition technique

PURPOSE: To assess the diagnostic accuracy of integrated parallel acquisition technique (iPAT) in local staging of rectal carcinoma in comparison to conventional high-resolution MRI. MATERIALS AND METHODS: A total of 28 patients with a neoplasm of the rectum and 15 control patients underwent MRI of the pelvis. High-resolution images were acquired conventionally and with iPAT using a modified sensitivity encoding (mSENSE). Image quality, signal-to-noise and contrast-to-noise ratios (SNR, CNR), tumor extent, nodal status, and delineation of the circumferential resection margin (CRM) were compared. In 19 patients with a carcinoma, MR findings were correlated with the histopathological diagnosis. Tumor distance to the CRM was matched with resection specimen in 12 cases. RESULTS: The comparison of both MR techniques revealed no clinically relevant differences in tumor staging and delineation of the CRM, though SNR and CNR were significantly lower in mSENSE images. Tumor stage was concordant in 17 of 19 cases compared to histopathology. In four of nine patients with T3 and T4 carcinomas, the histopathological resection margin was < or =2 mm, in five cases MRI predicted a margin of < or =2 mm. CONCLUSION: The application of iPAT in local staging of rectal carcinoma is time-saving and does not degrade diagnostic accuracy. Tumor stage, nodal status, and the CRM can be assessed equally compared to conventional acquisition techniques.     

Assessment of left ventricular function by breath-hold cine MR imaging: Comparison of different steady-state free precession sequences

PURPOSE: To compare steady-state free precession (SSFP) sequence protocols with different acquisition times (TA) and temporal resolutions (tRes) due to the implementation of a view sharing technique called shared phases for the assessment of left ventricular (LV) function by breath-hold cine magnetic resonance (MR) imaging. MATERIALS AND METHODS: End-diastolic and end-systolic volumes (EDV, ESV) were measured in contiguous short-axis slices with a thickness of 8 mm acquired in 10 healthy male volunteers. The following true fast imaging with steady-state precession (TrueFISP) sequence protocols were compared: protocol A) internal standard of reference, segmented: tRes 34.5 msec, TA 18 beats per slice; protocol B) segmented, shared phases: tRes 34.1 msec, TA 10 beats per slice; and protocol C) real-time, shared phases, parallel acquisition technique: tRes 47.3 msec, TA 24 beats for 12 slices covering the entire left ventricle. RESULTS: Phase sharing leads to a significant decrease in EDV, stroke volume (SV), and ejection fraction (EF) (median difference -7.0 mL [*], -9.6 mL, and -3.4%, respectively, for protocol B; -15.3 mL, -13.3 mL, and -2.4% for protocol C; P = 0.002, *P = 0.021). The observed median difference of real-time EDV and SV estimates is of clinical relevance. Real-time cine MR imaging shows a greater variability of EDV and SV. No relevant differences in ESV were observed. CONCLUSION: The true cine frame duration of both shared phases sequence protocols exceeds the period of isovolumetric contraction (IVCT) of the left ventricle resulting in a systematic and significant underestimation of EDV and consequently SV and EF. SSFP sequence protocol parameters, particularly tRes and use of view sharing techniques, should therefore be known at follow-up examinations in order to be able to assess LV remodeling in patients with heart failure.     

Combination of low and high resolution sequences in two orientations for dynamic contrast-enhanced MRI of the breast: more than a compromise

The purpose was to combine T1-weighted 3D gradient echo sequences at low and high spatial resolution (and short and longer acquisition time, respectively) in two orientations without compromising signal/time curve analysis and to evaluate the incremental value of assessing architectural features in high resolution images in dynamic contrast-enhanced MR mammography. T1-weighted 3D-FLASH sequences in a 1.5-T scanner (512×256 pixel matrix at high resolution; 256×128 pixels at low resolution sequences, 72 slices, 1.7-mm slice thickness, TR 8.8 ms, TE 4.5 ms, flip angle 25°) were acquired in a special order during a single investigation. Three observers evaluated architectural features of 36 histopathologically proven lesions using high or low resolution images independently. Architectural features of each lesion were assessed by rating on two three-point scales. Kappa statistics verified the decrease of inter-observer variability. All observers improved assessment of architectural features regarding high resolution images in transversal and coronal orientation (observer A: eight positive, three negative corrections; B: 12/5; C: 16/4). Most positive corrections resulted from improved detection of morphologic criteria of malignancy. Mean inter-observer agreement significantly (P<0.05) increased from slight to moderate (mean weighted increased from 0.185 to 0.422). This protocol at the charge of slightly enlarged time for measurement offers an elegant way to improve analysis of architectural features in MRM.