Minimizing the duration of laser Doppler flowmetry recordings while maintaining wavelet analysis quality: A methodological study.

Recording oscillations in cutaneous blood perfusion using laser Doppler flowmetry (LDF) is of common use in clinical research, due, mainly, to its non-invasive nature. Detailed information about the vascular tone in different frequency bands and the related physiologic compartment can be inferred from wavelet analysis (WA) of an LDF signal. However, little is known about the minimal recording duration required to generate a proper representation of the frequency content of such signals. To address this question, the three lowest frequency bands (i.e. myogenic, neurogenic and endothelial) of the LDF wavelet power spectrum were studied to define the shortest recording duration needed to perform a quality WA. Sixty-five healthy participants were included for 20 min of basal LDF recording on forearm and dorsum of the foot. Recordings were short cut every minute and compared to the 20-min reference recording that is generally used in the literature. Our results indicate that minimum 10 min recordings are required for analysis of myogenic events, whatever the anatomical site. On the forearm, LDF recordings lengths should be at least 15 min and 10 min for the neurogenic and endothelial bands, respectively. On the foot, 13 min of LDF recording is required to assess neurogenic and endothelial bands. Depending on the aim of any given study involving healthy subjects, LDF recordings need to last at least 15 min on forearm and 13 min on the foot to maintain a quality WA on low-frequency bands.

Small peptides (<5kDa) found in ready-to-eat beef meat.

Dietary proteins can have biological properties, many attributed to bioactive peptides (2-50 amino acids). Since little is known about peptides in meat, we investigated the postmortem occurrence of low molecular weight peptides (<5kDa) in bovine Pectoralis profundus muscle, after 14 days storage at 4°C and vacuum cooking for 90min at 75°C. The study combined quantitative (amino acid analysis) and qualitative approaches (mass spectrometry). Eighty-nine percent of peptidic amino acids in fresh muscle corresponded to carnosine, anserine and glutathione. Levels of these compounds were lower in cooked meat compared to fresh muscle. Concomitantly, numerous larger compounds, most probably peptides, were generated in a very reproducible manner during ageing and even more during cooking of meat. Seven peptides (fragments of troponin T, nebulin, procollagen and cypher proteins) were identified in cooked meat extracts.

Common bile duct obstruction by free floating tumor.

UNLABELLED: Tumors usually spread by local invasion or by vascular or lymphatic metastases. We report six patients in whom tumor cells were shed into the common bile duct with resulting obstruction. The three men and three women had jaundice and upper abdominal discomfort. Jaundice was intermittent in four patients. Preoperative total serum bilirubin ranged from 2.5 to 16.1 mg/dl; alkaline phosphatase ranged from 221 to 605 IU/1. Ultrasound showed a dilated gallbladder [GB] in five patients with dilated intrahepatic ducts in three and stones in only one. ERCP showed a single filling defect in two of three patients and multiple defects in one. PTC showed multiple defects in one patient. At operation a thick gelatinous tissue fragment or clot was seen in the common bile duct of each patient. Frozen section identified tumor tissue in all. The source was GB carcinoma [2], GB adenomyoma [1], hepatic metastases of colon cancer [2] and common bile duct cancer [1]. Treatment consisted of pancreaticoduodenectomy [2], including one for GB cancer, left hepatic lobectomy [1], choledochoduodenostomy [1], common duct exploration with T-tube insertion [1] and cholecystectomy [1]. One patient with metastatic colon cancer and another with gallbladder cancer died within one year of operation. The other four are alive from 2 to 4 years later. CONCLUSION: Benign or malignant tumors within the hepatobiliary tree can shed tissue into the common bile duct which can cause biliary obstruction. Any tissue fragment found in the common bile duct should be evaluated by frozen section. Recognition of this mode of tumor spread is needed for appropriate therapy of the underlying benign or malignant tumor.

Radiologic diagnosis of an intra-abdominal abscess. Do multiple tests help?

A review was made of the charts of 94 patients who underwent ultrasonography (US), computed tomography (CT), and gallium citrate Ga 67 (Gall) scan to rule out intra-abdominal abscesses. Of all the clinical and laboratory data, only the presence of pain and tenderness differentiated patients with and without abscesses. A review of radiologic data showed that CT was superior to US, and that US was superior to Gall scan with regard to sensitivity, specificity, accuracy, and positive and negative predictive values. When multiple radiologic tests were performed, results agreed in 72% of cases; therefore, the additional tests were essentially redundant. When radiologic test results disagreed, accuracy rates were CT, 0.86; US, 0.00; and Gall scan, 0.44. These findings suggest that, except to rule out pelvic abscesses in the presence of pelvic inflammatory disease, CT is usually the only special radiologic test that should be performed to localize a suspected intra-abdominal abscess.

CT diagnosis of idiopathic aneurysms of the thoracic systemic veins.

Three patients with idiopathic aneurysms of the superior vena cava, left innominate vein, and inferior vena cava are presented. The advantages of CT over other diagnostic modalities are discussed.

Gallbladder wall thickening in preeclampsia.

Sonographic examination of the gallbladder in two patients with preeclampsia and right upper quadrant pain demonstrated notable thickening of the gallbladder wall. The sonographic abnormality and clinical symptoms completely resolved after delivery and/or medical management of the preeclampsia. This finding is probably secondary to the hypoalbuminemia characteristic of preeclampsia and should not be mistaken for intrinsic gallbladder disease.

Evaluation of superior vena cava syndrome by axial CT and CT phlebography.

Transverse axial computed tomography (CT) has been combined with CT digital phlebography to study nine patients with superior vena cava syndrome. Six were due to malignancy, two were secondary to benign disease, and one was a paraneoplastic manifestation. This combined CT approach successfully identified the abnormal morphology of the superior vena cava, demonstrating external compression, encasement, or intraluminal thrombus in all patients and the collateral venous channels in eight. The efficacy and advantages of this technique are discussed. This technique is a rapid, informative, and cost-effective method for the workup of superior vena cava syndrome. The CT digital phlebogram, however, is not successful in regularly and optimally opacifying the normal superior vena cava because of the limited amount of contrast material, dilution effect of the nonopacified incoming flow from the jugular and azygos veins, and the lack of image enhancement from the CT digital scanograms.

Intravenous contrast bolus in computed tomography investigation of mass lesion.

Using bolus intravenous contrast (25-75 Renografin 60) and 5-second scanning capability, better definition of vascular anatomy as well as the vascular nature of mass lesions in the chest and abdomen could be demonstrated. The immediate higher concentration of iodine in vessels and organs following initial bolus, improves visualization of these structures dramatically when compared to drip-infusion technique. A description of the technique and examples are shown.

Metastatic leiomyosarcoma of the kidney with spontaneous perirenal hemorrhage.

Spontaneous subcapsular or perirenal hemorrhage is most often associated with a primary renal neoplasm which may be malignant or benign. No case of metastasis to the kidney causing such hemorrhage has been reported. The patient presented here had spontaneous perirenal hemorrhage due to metastasis to the kidney from a leiomyosarcoma of the uterus.

Chronic stridor in a child: CT diagnosis of pulmonary vascular sling.

A child without chronic stridor and tracheal narrowing was considered to have a primary tracheal abnormality. Computed tomography (CT) identified an aberrant left pulmonary artery originating from the right pulmonary as the cause of the tracheal abnormality. The advantages of CT over conventional studies are discussed.

Diagnosis of dissecting aortic aneurysm by computed tomography.

Computed tomography (CT) of the torso combined with simultaneous intravenous bolus injection of contrast media was used in sixteen patients suspected of having dissected their aorta. All patients had subsequent correlative percutaneous aortography within 24 h of the CT examination. Four patients proved to be normal, one had an aneurysm of the thoracic aorta, and eleven had aortic dissection (five type I, six type III dissection). All eleven patients with aortic dissections were diagnosed by CT and angiography; nine had spontaneous dissections and two had iatrogenic injuries to the aorta. Limitations of this imaging procedure include; inability to detect aortic valvular dysfunction and failure to provide an adequate perspective of aortic branch involvement. Potential benefits include: avoidance of aortogram in some cases, relative non-invasiveness, rapidity and ease of procedure, and less expense, radiation, contrast media, and discomfort to the patient. Early experience with CT-enhancement technique has reliably demonstrated normal as well as abnormal aortic wall morphology. It may have a place as an alternative to the conventional aortogram.