Hypothermia and thiopentone sodium: individual and combined neuroprotective effects on cortical cultures exposed to prolonged hypoxic episodes

Because there are many conflicting reports on cerebroprotective effects of hypothermia and barbiturates, we examined the degree of neuroprotection at defined temperatures (normothermia, 37 degrees C; mild hypothermia, 32 degrees C; deep hypothermia, 22 degrees C; and profound hypothermia, 17 degrees C) and various concentrations (low, 4 microM; moderate, 40 microM; and high, 400 & microM) of thiopentone sodium (TPS), alone and in combination in cortical cultures exposed to prolonged hypoxia (24-48 hr). The survival rate of embryonic day (E)16 Wistar rat cortical neurons was evaluated on photomicrographs before and after experiments. During the 24-hr hypoxic period, the survival rate of neurons was maximal with combinations of mild hypothermia with 40 microM (91.6 +/- 0.7%) and 400 microM TPS (90.8 +/- 0.7%) or deep hypothermia combined with all concentrations of TPS (4 microM, 90.6 +/- 1.0%; 40 microM, 91.4 +/- 0.8%; 400 microM, 91.8 +/- 1.2%). During 48 hr hypoxia, the highest survival rate was seen with the combination of deep hypothermia and either 40 microM (90.9 +/- 0.6%) or 400 microM (91.1 +/- 1.4%) TPS. In the presence of profound hypothermia in combination with all concentrations of TPS, the survival rate was significantly reduced (P< 0.01) compared to combined application of either mild or deep hypothermia with TPS. In summary, maximal neuroprotection was attained with hypothermia and TPS in combination rather than applied individually, during prolonged hypoxic episodes (24- 48 hr). During a 24-hr hypoxic period, both mild and deep hypothermia combined with a clinically relevant concentration of TPS (40 microM) offered the highest neuroprotection. Only deep hypothermia provided maximal neuroprotection when combined with 40 microM TPS, during 48-hr hypoxia. Combination of profound hypothermia and TPS did not confer considerable neuroprotection during long lasting hypoxia.     

In Vitro and In Vivo Validation Tests for Total Artificial Heart

Abstract: Properly planned in vitro and in vivo studies are mandatory to validate blood pump performance. However, standard procedures for in vitro and in vivo tests of total artificial heart (TAH) performance still do not exist. At Baylor College of Medicine, standard tests procedures for performance validation of the totally implantable TAH have been established. In this paper, these in vitro tests protocols (performance mapping tests, accelerated endurance test, hemolysis test, flow visualization tests, etc.) are described as well as in vivo test procedures (TAH implantation procedure, including surgical technique, postoperative management and tests, etc.). In addition, pathological protocols are presented. In our experience, these procedures are very simple, easy to perform, and inexpensive. These protocols are proposed as standard in vitro and in vivo tests for a TAH.     

Adenocarcinoma of the Lung with Selective Metastasis to the Lung: Clinical, Histologic and DNA-Cytofluorometric Analyses

In order to examine selective lung metastasis in lung adenocarcinoma, 7 patients who had died due to metastasis exclusively to the lung were analyzed. Because all of the tumors had been well differentiated adenocarcinoma, 21 cases of well differentiated adenocarcinoma which had metastasized to both the lung and other distant organs were selected as controls. Histologically, 6 of the 7 study cases were bronchiolo-alveolar carcinoma (BAC) of variable cytological type or papillary adenocarcinoma with a thin fibrovascular stroma without apparent destruction of the alveolar wall. There was no difference in clinical findings or nuclear DNA content (NDC) between the BAC and papillary adenocarcinoma with thin fibrovascular stroma. The fibrovascular stroma in the study cases was significantly thinner than that in the control cases ( P <0.01). Cytofluorometrically, the study cases had a significantly lower and less abnormal NDC than the control cases in terms of the mean NDC and DNA histogram patterns ( P <0.01 and P <0.05, respectively). On the basis of these findings, we conclude that 1) BAC can be classified within the same spectrum as well differentiated papillary adenocarcinoma, and 2) selective lung metastasis occurs in well differentiated adenocarcinomas showing mild NDC abnormalities and having a thin fibrovascular stroma without apparent destruction of the alveolar wall.     

Clinical effect of oxybutynin hydrochloride (1 mg/tablet)

The clinical efficacy of oxybutynin hydrochloride was studied on 21 patients with neurogenic bladder or unstable bladder complaining of urinary frequency, urgency and urgent incontinence. Oxybutynin hydrochloride (1 mg/tablet) was administered orally for 26.7 days, on average, 3 mg per day in 3 and 6 mg per day in 18 patients and the usefulness of this drug was assessed subjectively and objectively. Of 21 patients treated, 9 had neurogenic bladder and 10 had unstable bladder. Urinary frequency was normalized in 6 out of 16 (37.5%), urgency ceased in 6 out of 17 (35.7%) and urgent incontinence disappeared in 9 out of 14 (50%) patients. The mean volume at the first desire to void and the maximum cystometric capacity increased significantly on the cystometrogram after the administration of oxybutynin hydrochloride (p less than 0.01). Furthermore, the maximum vesical pressure decreased significantly (p less than 0.05). The maximum urinary flow rate increased slightly (p less than 0.1) and the residual urine volume significantly increased (p less than 0.05) after medication, although no changes were observed in tidal voiding volume or mean urinary flow rate. Of 20 patients, 9 showed improvement globally (45%), although no subjective or objective improvement was observed in 4 (20%) patients. Marked side effects were observed in 5 cases (two of acute urinary retention, each of increased urgency, residual urine and liver dysfunction), and side effects were seen in 10 of the 21 (47.6%) patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

Development of an Atraumatic Small Centrifugal Pump for Second-Generation Cardiopulmonary Bypass

A small and light direct-drive centrifugal pump has been developed for cardiopulmonary bypass. In the development process, blood compatibility studies including a hemolysis study, an in vitro fluid dynamic performance study, and in vivo durability and feasibility studies were performed. The centrifugal pump with a 50 mm diameter impeller resulted in almost the same index of hemolysis value as did a Bio-Medicus centrifugal pump. Heat dissipation from the motor was prevented by using a flexible drive cable. Forty-eight-hour sealing durability around the driving axis was accomplished by using a fluoro-rubber V-ring that connected to the hard chrome-plated stainless steel. In vitro and in vivo performances of the pump were satisfactory. Thrombus formation behind the impeller was prevented by using a holed impeller that generated blood flow from the back to the surface of the impeller. Elimination of air during priming procedures was also easier with this modification. This centrifugal pump has one-quarter of the priming volume, size, and weight of magnetically coupled centrifugal pump systems.     

The expression of stage-specific embryonic antigen 1 in the noncancerous colorectal epithelia of familial polyposis coli

The epithelial expression of carbohydrate antigen, stage-specific embryonic antigen 1 (SSEA-1) was examined immunohistochemically in noncancerous specimens from patients with familial polyposis coli, and compared with the colorectal epithelia from patients with sporadic colorectal cancer. In mucosa remote from carcinoma of sporadic cases, SSEA-1 was expressed only faintly in the lower crypts. In mucosa adjacent to carcinoma of sporadic cases, SSEA-1 was expressed not only in the lower crypts but also in the upper crypts. These results corresponded to those observed in the authors' previous study. In the flat mucosa of familial polyposis coli cases, SSEA-1 was detected not only in the lower crypts, but also in both upper crypts and the surface epithelium in contrast with the flat mucosa of sporadic cases. The staining pattern in the upper crypts of the flat mucosa of familial polyposis coli cases was very similar to that of the mucosa adjacent to carcinoma of sporadic cases, but was stronger and more diffuse in the surface epithelium. In microscopic adenomas, SSEA-1 was expressed diffusely. These results demonstrate that the flat mucosa of patients with familial polyposis coli shows preneoplastic changes similar to those in the mucosa adjacent to carcinoma of sporadic cases, and that SSEA-1 is related to adenoma formation in the early stage of carcinogenesis in the colorectum. In addition, the results suggest that immunohistochemical studies of flat mucosa may be useful for the early detection of high-risk individuals in a familial polyposis coli family. Some of the data in this study were presented at the meeting of the XIth Biennial Congress of the International Society of University Colon and Rectal Surgeons, Dallas, Texas. May 1986. Supported in part by a grant from Ministry of Education, Science and Culture, Japan.     

Totally Implantable Total Artificial Heart and Ventricular Assist Device with Multipurpose Miniature Electromechanical Energy System

Abstract: A multipurpose miniature electromechanical energy system has been developed to yield a compact, efficient, durable, and biocompatible total artificial heart (TAH) and ventricular assist device (VAD). Associated controller-driver electronics were recently miniaturized and converted into hybrid circuits. The hybrid controller consists of a microprocessor and controller, motor driver, Hall sensor, and commutation circuit hybrids. The sizing study demonstrated that all these components can be incorporated in the pumping unit of the TAH and VAD, particularly in the centerpiece of the TAH and the motor housing of the VAD. Both TAH and VAD pumping units will start when their power line is connected to either the internal power pack or the external battery unit. As a redundant driving and diagnostic port, an emergency port was newly added and will be placed in subcutaneous location. In case of system failure, the skin will be cut down, and an external motor drive or a pneumatic driver will be connected to this port to run the TAH. This will minimize the circulatory arrest time. Overall efficiency of the TAH without the transcutaneous energy transmission system was 14–18% to deliver pump outputs of 4–9 L/min against the right and left afterload pressures of 25 and 100 mm Hg. The internal power requirement ranged from 6 to 13 W. The rechargeable batteries such as NiCd or NiMH with 1 AH capacity can run the TAH for 30–45 min. The external power requirement, when TETS efficiency of 75% was assumed, ranged from 8 to 18 W. The accelerated endurance test in the 42°C saline bath demonstrated stable performance over 4 months. Long-term endurance and chronic animal studies will continue toward a system with 5 years durability by the year 2000.