Development and Initial Testing of a Permanently Implantable Centrifugal Pump

Abstract: To be able to salvage heart failure patients, the need for an economical permanent ventricular assist device is increasing. To meet this increasing demand, a miniaturized centrifugal blood pump has been developed as a permanently implantable device. The Gyro permanently implantable model (PI-601) incorporates a sealless design with a blood stagnation free structure. The pump impeller is magnetically coupled to the driver magnet in a sealless manner. This pump is atraumatic and antithrombogenic and incorporates a double pivot bearing system. A miniaturized actuator was utilized in this system in collaboration with the University of Vienna. The priming volume of this pump is 20 ml. The overall size of the pump actuator package is 53 mm in height and 65 mm in diameter, 145 ml of displacement volume, and 305 g in weight. Testing to date has included in vitro hydraulic performance and hemolysis. This pump can provide 5 L/min against a 110 mm Hg total pressure head at 2,000 rpm and 8 Limin against 150 mm Hg at 2,500 rpm. The normalized index of hemo-lysis (NIH) value of this pump was 0.0028 g/100 L at 5 Limin against 100 mm Hg. A preliminary anatomical study revealed the possibility of the implantability of 2 such systems in biventricular bypass at a preperitoneal location. This system is feasible for use as a permanently implantable biventricular assist device.     

Low-pressure Pneumoperitoneum for Laparoscopic Surgery Using a Disposable,Flexible Abdominal Wall Retractor

Abstract: Since April 1991, we have studied 160 patients who had had a successful laparoscopic cholecystectomy. Nine patients who presented with chronic cholecystitis with severe local adhesion and who were also considered to require a longer operative time were selected as suitable candidates for this procedure. They were successfully treated under a zero- to four-mmHg low-pressured pneumoperitoneum procedure combined with total abdominal wall lifting using a disposable, flexible vinyl tube retractor. This method enabled exactly the same clear laparoscopic vision as is possible in the routinely-used high-pressure pneumoperitoneum even in the marginal portions of the abdominal cavity. Moreover, it facilitated early reinsufflation after the cauterization-produced smoke was exhausted, which minimized the operative time and reduced the surgeon's anxiety concerning the maintenance of a sufficiently airtight condition. We believe that this low-pressure pneumopeqitoneum procedure also benefits the poor-risk patient who has restricted cardiopulmonary function, especially during advanced laparoscopic surgery which requires a longer operative and anesthetic time.     

Long-Term Follow-Up of the Changes in Circulating Cytokines, Soluble Cytokine Receptors, and White Blood Cell Subset Counts in Patients with Rheumatoid Arthritis (RA) After Monoclonal Anti-TNFα Antibody Therapy

To investigate the mechanism of the long-lasting efficacy of chimeric monoclonal anti-TNF antibody (cA2) therapy for rheumatoid arthritis (RA), eight patients with refractory RA were treated with a single infusion of cA2 and the changes in circulating cytokines (IL-1, IL-6, TNF, and IL-10), soluble cytokine receptors (TNF-RI, RII, and sIL-6R) and peripheral white blood cell (WBC) subset counts were followed up long-term (12 weeks) after cA2 therapy in them. Significant clinical responses (>20% improvement according to Paulus' criteria) were observed just after cA2 infusion and lasted more than 4 weeks in all patients, as reported elsewhere. Moreover, five of the eight patients showed prolonged clinical responses (>12 weeks). The elevated serum IL-6 and sTNF-RI (or RII) levels before treatment rapidly decreased after treatment. The serum IL-10 levels also significantly elevated before treatment. The elevations of serum IL-10 levels were augmented after treatment and stayed higher than the baseline in four patients with prolonged clinical responses. No significant TNF, IL-1 and -, or sIL-6R were detected in the sera of the patients before treatment and during the whole study period. On the other hand, peripheral lymphocytes as well as total WBC and neutrophils increased for 4 weeks after treatment. However, thereafter, only the lymphocyte count decreased gradually and stayed below the baseline long-term (12 weeks). FACS analysis revealed the predominance of T lymphocytes in the decrease in lymphocyte counts. These results suggest that the augmentation of IL-10 production and the decrease in T cells might partly contribute to the long-lasting efficacy of cA2 treatment in RA.     

Infiltrating eosinophils and eotaxin: their association with idiopathic eosinophilic esophagitis.

BACKGROUND: Idiopathic eosinophilic esophagitis (IEE) is a very rare disease characterized by thickening and eosinophil infiltration of the esophagus. The most potent chemotactic factor for eosinophils is eotaxin, and its pathophysiologic significance in IEE needs to be elucidated. OBJECTIVE: To study the association between eotaxin and IEE. METHODS: We examined eotaxin expression in the esophagus of an IEE patient in comparison to controls by immunohistochemistry using a monoclonal antibody for human eotaxin. We also measured the free eotaxin level and the total (free and bound-form) eotaxin level in blood by enzyme-linked immunosorbent assay before and after the initiation of steroid therapy. RESULTS: Most of the infiltrating eosinophils in the affected esophageal tissue showed immunohistochemical staining with anti-eotaxin antibody. In blood samples, the free eotaxin level was slightly elevated before treatment, whereas the total eotaxin level was within the normal range. Unexpectedly, the total eotaxin level increased dramatically after the initiation of steroid therapy, whereas the increase of free eotaxin was modest. CONCLUSION: Infiltrating eosinophils that express eotaxin and the changes of blood eotaxin levels during steroid therapy suggest that eotaxin may be associated with IEE.     

Evaluation of the drug lymphocyte stimulation test (DLST) with shosaikoto]

BACKGROUND: Our aim is to evaluate the significance of DLST by Shosaikoto. METHODS: We clinically evaluated 3 cases of drug-induced pneumonia assumed to be caused by Shosaikoto, and we performed DLST of Shosaikoto for healthy controls, and compared the data with drug-induced pneumonia cases of Shosaikoto. RESULTS: As clinical characteristics of 3 cases, 2 cases were positive for hepatitis C virus antibody, and 1 case was positive for DLST of Shosaikoto. The observed chest high-resolution CT (HRCT) findings showed hypersensitivity pneumonia (HP) pattern in all 3 cases. Prognosis was good in all 3 cases. DLST of Shosaikoto was positive in 27.5% of healthy controls. Stimulation index (S.I.) of DLST in drug-induced pneumonia cases increased depending on drug dilution density, compared to that of healthy controls. CONCLUSION: DLST of Shosaikoto showed high false-positive rate. However, we may be able to distinguish the true-positive cases with the false-positive cases by comparing the S.I. of DLST according to drug dilution density.