Improved high performance liquid chromatography determination of hippuric acid and methylhippuric acid isomers in urine

A study was made on the effect of detection wavelength and separation mode of HPLC on determination of urinary hippuric acid (HA) and three isomers of methylhippuric acid (MHA). The interference of other constituents of urine in the determination was effectively decreased by detection at a short wavelength of 227.6 nm. Meta and para MHAs were separated by the addition of beta-cyclodextrine to the mobile phase. Four metabolites were successfully separated from other components of urine by the combination of ODS-silica packed-column and mobile phase (method F). The detection limits were found to be 50 and 5 mg/l for HA and MHAs, respectively. MHAs could not be detected in the non-exposed subjects. Average levels (+/- SD) of HA in non-exposed males and females were 272.2 (+/- 210.8) and 393.0 (+/- 269.8) mg/l, respectively. The urinary levels of HA in females were significantly higher than those in males.     

In Vitro Evaluation of Platelet/Biomaterial Interactions in an Epifluorescent Video Microscopy Combined with a Parallel Plate Flow Cell

Abstract: Suitable evaluation systems are critical for ranking various biomaterials in order to develop a method to design and synthesize nonthrombogenic biomaterials. We have recently developed an in vitro test system to evaluate platelet/biomaterial interactions in whole blood. The system consists of a parallel plate flow cell and epifluorescent video microscopy (EVM). A glass coverslip coated with a polymer was incorporated into the flow cell, and blood was perfused using a syringe pump via a polymer–coated PVC tubing connected to the flow cell. Whole human blood was anticoagulated with heparin (2 U/ml), and the platelets were labeled with the fluorescent dye mepacrine (5 μM). This system permitted real–time and dynamic observations of platelet/biomaterial interactions in whole blood under a defined flow condition. In order to evaluate the feasibility of this system, two different segmented polyether–polyurethanes (SPEUs), PU–PTMG(650) and PU–PTMG(2000), were chosen as test polymers. Surface characteristics verified with electron spectroscopy for chemical analysis (ESCA) and contact angle measurements showed similar results in both SPEUs. Blood was perfused at a wall shear rate of 200 s^–1 for 20 min. Excitation light was applied for 2 s at 1 min intervals. The real–time image was then analyzed at each time point for the percentage of surface area of platelet coverage. Plasma β–thromboglobulin (β–TG) levels were also measured before and after each run. PU–PTMG(650) showed a significantly higher number of adhered platelets than PU–PTMG(2000) at each time point. β–TG levels of PU–PTMG(650) were also higher than those of PU–PTMG(2000), which is comparable to the results of EVM. Thus, this EVM system has been proven to be an excellent and highly sensitive in vitro analytical method for evaluating platelet/biomaterial interactions.     

Dynamic MRI of the gallbladder lesions: Differentiation of benign from malignant

Forty-nine pathologically proven gallbladder lesions were evaluated in 45 patients using dynamic MRI with a spoiled gradient pulse sequence (SPGR), to access the ability of this technique to differentiate benign from malignant gallbladder lesions. The studies were reviewed retrospectively. Signal intensity of the lesions were measured. Twenty-one malignant and 28 benign lesions were classified into three categories: polypoid, diffuse wall thickening, and exophytic. Early and delayed enhancement patterns were evaluated. For the polypoid masses, malignant lesions (n = 9) demonstrated early and prolonged enhancements, whereas benign lesions (n = 14) had early enhancement with subsequent washout (P < .05). For diffuse gallbladder wall thickening, malignant lesions (n = 6) demonstrated early and prolonged enhancement and benign lesions (n = 14) showed relatively slow, prolonged enhancement (P < .05). The exophytic masses (n = 6) all were malignant and demonstrated early and prolonged enhancement. Dynamic MRI can help differentiate benign from malignant gallbladder lesions.     

Genetic alteration in carcinoid tumors of the lung.

Surgically resected specimens of 13 carcinoid tumors of the lung including nine typical carcinoids and four atypical carcinoids, and eight salivary gland type carcinomas (six mucoepidermoid carcinomas and two adenoid cystic carcinomas) were analyzed regarding p53 expression, loss of heterozygosity (LOH) in chromosome 3p, 9p, and K-ras mutation. The overexpression of p53 was identified in four atypical carcinoid tumors, one mucoepidermoid carcinoma, and one adenoid cystic carcinoma, however, none of typical carcinoids showed p53 immunoreactivity. LOH in 3p14 was demonstrated in three of seven informative cases in all tumors. LOH in 9p was demonstrated in two of five informative cases in all tumors. Two of three cases with LOH at 3p14 had a poor prognosis, one of which also had LOH at 9p. No mutation of the K-ras gene was observed in any of these tumors. These data thus indicate that p53 overexpression might distinguish atypical carcinoid tumors from typical tumors and might therefore be useful as an adjunct modality in the differential diagnosis of pulmonary carcinoid tumors. The presence of LOH at 3p14 or 9p may thus help to identify lung cancer patients with a poor prognosis.     

Cystic radiolucencies of carpal bones, distal radius and ulna as a marker for dialysis-associated amyloid osteoarthropathy.

Patients on long-term hemodialysis (HD) are known to develop amyloid osteoarthropathy, evidenced as cystic radiolucencies on X-rays of the affected joints. To study the relationship between cystic radiolucencies and amyloid osteoarthropathy in 394 patients, we classified the severity of the cystic radiolucencies seen in the wrist joint on a 4-point scale and evaluated the association between lesion severity (grade) and several parameters. Biopsy was performed in 8 patients with 11 bone cysts of the wrist joint who had been operated for carpal tunnel syndrome. HD for 10 years or longer, age 50 or older and the presence of carpal tunnel syndrome were associated with severe cyst rating. There was no association between lesion grade and serum level of PTH-C, aluminum or beta 2-microglobulin (B2M). Ten of the 11 biopsied bone cysts in 8 patients with carpal tunnel syndrome demonstrated amyloid deposits which reacted with B2M. We conclude that a cystic radiolucency observed in the wrist joint of a patient undergoing HD indicates the deposition of amyloid. The cyst grade provides a useful marker for the severity of amyloid osteoarthropathy in HD patients.     

Leiomyosarcoma originating in Meckel's diverticulum: Report of a case and a review of 59 cases in the English literature

A 49-year-old woman was referred to our hospital with complaints of epigastric colicky pain and high fever. Abdominal computed tomography and ultrasonography showed a solid tumor in the lower abdomen. Laparotomy revealed a neoplastic mass arising in Meckel's diverticulum; therefore, a segment of the ileum, including the tumor-possessing diverticulum, was resected with a lymph node dissection. A histologic examination confirmed the lesion to be leiomyosarcoma. In the English literature, 59 cases of leiomyosarcoma in Meckel's diverticulum were reported from 1941 to 1994. The majority of patients were in their 4th decade of life, with both sexes equally affected. The most frequent symptoms associated with this disease were abdominal pain with nausea, vomiting, and melena. The majority were larger than egg-size. Although Meckel's diverticulum is difficult to diagnose preoperatively, mesenteric arteriography may at times prove useful. The standard management of this particular tumor is wide segmental resection, including the tumor and diverticulum with lymph node dissection.     

Downhill esophageal varices due to superior vena cava syndrome

This study examined the incidence of downhill esophageal varices due to SVC syndrome. The presence of downhill esophageal varices was examined by esophagoscopy or autopsy. Downhill esophageal varices were detected in two of nine (22%) patients with SVC syndrome. One case was a 66-year-old male case who and underwent upper lobectomy for lung cancer in September 1985. He developed SVC syndrome due to recurrence in 1986 and died in 1987. Downhill esophageal varices wer in the upper esophagus by esophagoscopy and confirmed by autopsy. The another case was a 61-year-old female who developed carcinoma of the tongue in 1986 and lymph node metastasis to the mediastinum in 1987. Autopsy revealed downhill esophageal varices in the upper and middle esophagus. Eleven cases of downhill esophageal varices due to SVC syndrome reported in Japan were reviewed and discussed.     

Normothermic cardiopulmonary bypass: effect on the incidence of persistent postoperative neurological dysfunction following coronary artery bypass graft surgery

We retrospectively reviewed the records of 250 consecutive patients undergoing coronary artery bypass graft surgery (CABG) from January 1994 through January 1996 to determine the incidence of persistent postoperative neurological dysfunction after CABG and to compare normothermic and moderate hypothermic cardiopulmonary bypass (CPB). Normothermic CPB was used in 128 patients (36°–37°C) and hypothermic CPB (27°–28°C) in 122 patients. Postoperative neurological dysfunction included focal motor deficits, delayed recovery of consciousness (>24h) after surgery, and seizures within 1 week postoperatively. Persistent neurological dysfunction was diagnosed if complete resolution had not occurred within 10 days of surgery. The incidence of persistent postoperative neurological dysfunction was 4.1% in the hypothermic CPB group and 2.3% in the normothermic CPB group. There were no statistically significant differences between the two groups (P=NS). These results suggest that normothermic CPB did not increase the incidence of persistent postoperative neurological dysfunction compared to hypothermic CPB.     

Proton NMR studies on ischemic rat brain tissue.

The spin-lattice relaxation time (T1) of water protons and the cross-relaxation time (TIS) between irradiated protein protons and observed water protons were measured in order to study water-macromolecular interactions in ischemic rat brain tissues. Tissues were obtained by bilateral common carotid artery occlusion from stroke-prone spontaneously hypertensive rats. Water, Na, and K contents were measured in ischemic brain tissue at the same time. Water and Na content increased while the TIS value and K content decreased following ischemic insults. The T1 value did not change until 180 min after ischemia had been induced. Changes in the TIS value occurred earlier than changes observed for the T1 value, water, and electrolyte contents. Results indicate that the value of TIS may be useful for detecting cerebral ischemia and that the physical structure of water-macromolecular interaction may be altered soon after ischemic onset in brain tissue.