Experimental Study About Removal of the Implanted Tined Polyurethane Ventricular Lead by Radiofrequency Waves Through the Lead

Polyurethane pacemaker leads are widely used nowadays. However, only a few studies have been done to investigate the fixation mechanism of polyurethane leads. To elucidate how pacemaker leads are fixed at the early phase after implantation, polyurethane-insulated tined ventricular leads were implanted in seven mongrel dogs. One to 4 months later, tips of the leads were anchored among the trabeculae and the distal part of the leads were encapsulated by whitish fibrous tissue. It was found that not organized thrombi, but cell reaction with various stages of inflammatory cells was responsible for forming the fibrous tissue. We attempted to remove the lead by delivering radiofrequency wave through the lead. However, no lead could be removed.     

Diastolic Mitral Regurgitation in Patients with First-Degree Atrioventricular Block

Diastolic mitral regurgitation has been observed in patients with DDD pacemakers when the atrioventricular (AV) delay was prolonged. However, diastolic mitral regurgitation associated with first-degree AV block has not been fully studied. We examined transmitral blood flow in 24 patients with first-degree AV block and normal cardiac function (ages 35.3 ± 17.4 years), and in nine patients with DDD pacemakers and normal cardiac function (ages 73.1 ± 8.1 years), using pulsed Doppler echocardiography. Diastolic mitral regurgitation was observed in 19 of 24 patients with first-degree AV block. Although PQ interval was shortened from 0.32 ± 0.06 to 0.20 ± 0.05 seconds (P < 0.01) after 1 mg atropine sulfate IV, the interval between P wave (ECG) and the beginning of diastolic mitral regurgitation did not change, while the duration of diastolic mitral regurgitation was shortened from 0.15 ± 0.03 to 0.05 ± 0.03 seconds (P < 0.01). There was a significant correlation between changes in PQ interval and changes in the duration of diastolic mitral regurgifation (r = 0.92, P < 0.001). Although cardiac output (3.9 ± 0.05 L/min) and pulmonary capillary wedge pressure (5.1 ± 1.5 mmHg) were normal in all patients with pacemakers, diastolic mitral regurgitation was observed when the AV delay was prolonged. The critical PQ interval for the appearance of diastolic mitral regurgitation was 0.23 ± 0.01 seconds. In patients with prolonged PQ intervals, delayed ventricular contraction following atrial contraction may be associated with mitral regurgitation in the presence of a reversed AV pressure gradient. The results of this study suggest that diastolic mitral regurgitation occurs not only in patients with DDD pacemakers, but also with AAIR pacemakers when the PQ interval is prolonged. The occurrence of diastolic mitral regurgitation is associated with the pacing mode or the setting of AV delay.     

Pharmacokinetic behaviour in polymorphonuclear leucocytes of N,N-dimethylcarbamoylmethyl α,2-dimethyl-5H-[1]benzopyrano[2,3-b]-pyridine-7-acetate (Y-23023), a new prodrug type of antiinflammatory agent,and indomethacin after oral administrations in rats

Abstract— N,N-Dimethylcarbamoylmethyl α,2-dimethyl-5H-[1]-benzopyrano[2,3-b]pyridine-7-acetate (Y-23023) is a prodrug developed as a new non-steroidal anti-inflammatory drug (NSAID). Y-23023 is rapidly hydrolysed to an active metabolite, α,2-dimethyl-5H-[1]benzopyrano[2,3-b]pyridine-7-acetic acid (M₁) following its absorption and then exhibits a strong anti-inflammatory activity. We have examined the pharmacokinetic behaviour in polymorphonuclear leucocytes (PMNs) of M₁ and of indomethacin after oral administration to rats of Y-23023 and indomethacin, respectively. Y-23023 was rapidly absorbed, producing a mean C_max (1·13 μg mL^?1) of M₁ after 1 h in plasma. Indomethacin was less rapidly absorbed, producing a mean C_max (3·38 μg mL^?1) after 3 h in plasma. The mean AUC of M₁ and indomethacin in plasma were 5·45 μg h mL^?1 and 22·49 μg h mL^?1, respectively. The mean t_max, C_max and AUC of M1 in PMNs were 1 h, 11·1 ng (41 pmol)/10⁸ cells and 58·6 ng (164 pmol) h/10⁸ cells, respectively. The same parameters for indomethacin in the PMNs were 3 h, 15·4 ng (57 pmol)/10⁸ cells and 95·2 ng (266 pmol) h/10⁸ cells, respectively. The PMNs/plasma ratio of M₁ was about 2·8 times that of indomethacin. These results indicate that the association of M₁, an active metabolite of Y-23023, from blood to the PMNs is greater than that of indomethacin.     

Enhancement of J–ST-Segment Elevation by the Glucose and Insulin Test in Brugada Syndrome

NOGAMI, A., et al. : Enhancement of J–ST-Segment Elevation by the Glucose and Insulin Test in Brugada Syndrome. The effects of glucose and insulin on J–ST-segment elevation were evaluated in seven men   (mean age 45 ± 10 years)   with Brugada syndrome. Six patients had been reanimated from VF and one patient had experienced syncope. The effects of intravenous (1) pilsicainide 50 mg, (2) glucose 50 g, and (3) glucose 50 g plus regular insulin 10 IU on the precordial ECG leads were examined. Pilsicainide significantly enhanced J-ST elevation in all patients and induced VF in 1 patient. A significant accentuation of the abnormal J-ST configuration was observed in all patients at a mean of   51 ± 40   minutes after glucose and insulin infusion. Changes in blood glucose and serum potassium concentration were   111 ± 158 mg/dL   and   −0.30 ± 0.48 mEq/L   , respectively. These changes were not directly related to the ECG changes. Glucose infusion without insulin caused a subtle increase in J-ST elevation. In conclusion, the administration of glucose and insulin safely unmasked or accentuation the J–ST-segment elevation in Brugada syndrome. Blood glucose and insulin concentrations may be factors modulating the circadian or day-to-day ECG variations in this syndrome. (PACE 2003; 26[Pt. II]:332–337)     

Phase II trial of carboplatin and infusional cyclosporine with alpha-interferon in recurrent ovarian cancer: a California Cancer Consortium Trial

The purpose of this study was to estimate the response rate of 26-h continuous infusion cyclosporine A (CSA) combined with carboplatin (CBDCA) and subcutaneous alpha-interferon (IFN), in recurrent ovarian cancer (OC), and to measure their effects on CBDCA pharmacokinetics. OC patients relapsing following platinum-based chemotherapy received CBDCA area under the curve (AUC 3) with CSA and IFN, every 3 weeks. The pharmacokinetics of CSA and CBDCA were determined in a subset of patients. Thirty patients received 84 courses of therapy. Three partial responses were observed. Nine patients were stable for >4 months. Toxicity was similar to that observed in our previously reported phase I study and consisted of myelosuppression, nausea, vomiting, and headache. The mean end of infusion CSA level (high-performance liquid chromatographic assay [HPLC]) was 1109 +/- 291 microg/mL (mean +/- SD). CBDCA pharmacokinetics revealed a measured AUC of 3.61 versus a targeted AUC of 3, suggesting a possible effect of IFN on CBDCA levels versus errors in the estimation of CBDCA clearance using measured creatinine clearance. Steady-state levels of >1 microg/mL CSA (HPLC assay) are achievable in vivo. Insufficient clinical resistance reversal was observed in this study to warrant further investigation of this combination.     

Renal silica calculi in an infant

We report on a rare case of urinary silica calculi in a 10-month-old boy. The boy showed acute pyelonephritis with left hydronephrosis. Ultrasonography and computed tomography revealed a calculus at the left ureteropelvic junction and three additional calculi in the left renal pelvis. Because his acute pyelonephritis was refractory to conventional chemotherapy, the patient underwent successful left percutaneous nephrostomy followed by percutaneous nephrolithotripsy for the renal calculi. All stones disappeared and his postoperative course was uneventful. On infrared spectrophotometry, the wavelength pattern of the stones exhibited two peaks at 1100 and 1650 cm(-1), consistent with the determination that the calculi consisted of a mixture of silicate (78%) and calcium oxalate (22%). We consider that the etiology of the calculi in this child can be ascribed to the silicate-rich water used to dilute milk. In Japan, 46 adult patients with urinary silicate calculi have been reported in the literature; however, there is no report of the disease in an infant in Japan.     

CASE REPORT: Steatonecrosis in the upper abdomen following transcatheter arterial embolization for hepatocellular carcinoma

A 66-year-old female with liver cirrhosis was treated by transcatheter arterial embolization (TAE) for a small hepatocellular carcinoma. She developed steatonecrosis with tenderness which occurred in the upper abdomen after TAE. The hepatic falciform artery from the middle hepatic artery was detected by arteriography. Necrosis in the upper abdomen was considered to be due to ischaemic changes caused by micromaterials for embolization of this artery, injuries of hepatic arterial endothelia slowly caused by carcinostatics, and chemotoxicity. It was considered that such complication as observed in this patient should be taken into consideration when performing TAE.     

Kinetics of serum cytokines in adults undergoing peripheral blood progenitor cell transplantation

Summary. We investigated the serum cytokine levels (G-CSF, GM-CSF, IL-l/?, IL-3 and IL-6) using an ELISA in 14 patients with haematological malignancies undergoing peripheral blood progenitor cell transplantation (PBPCT). Serum G-CSF levels in all patients rose immediately after PBPCT, then gradually decreased as the neutrophil counts began to rise. No detectable serum levels of GM-CSF or IL-lp were observed, but serum levels of IL-3 rose transiently immediately following PBPCT. Serum levels of JL-6 rose transiently during a fever in four patients. These observations suggest that G-CSF and L 3 may contribute to the early haemopoietic reconstitution in PBPCT.