Molecular and Physiological Analysis of a Thylakoid K+ Channel Protein

Transport studies identified a K+ channel protein in preparations of purified spinach (Spinacea oleracea) thylakoid membrane. This protein was solubilized from native membranes and reconstituted into artificial proteoliposomes with maintenance of functional integrity. A 33-kD thylakoid polypeptide was identified as a putative component of this thylakoid protein. This identification was made using an antibody raised against a synthetic peptide representing a highly conserved region of K+ channel proteins. K+ channel activity co-migrated with the immunoreactive 33-kD polypeptide when solubilized thylakoid membrane protein was fractionated on a Suc density gradient. The antibody was used to immunoprecipitate the 33-kD polypeptide. Physiological function of this thylakoid membrane protein was elucidated by measuring photosynthetic electron transport of thylakoid preparations in the presence and absence of a K+ channel blocker. Results indicated that K+ efflux from the thylakoid lumen through this channel protein is required for the optimization of photosynthetic capacity. The effect this protein has on photosynthetic capacity is likely due to the requirement for K+ efflux from the thylakoid lumen to charge-balance light-induced proton pumping across this membrane.

Allelic variation in the Helicobacter pylori flagellin genes flaA and flaB: its consequences for strain typing schemes and population structure

Extensive DNA sequence diversity was noted in Helicobacter pylori flagellin genes flaA and flaB. PCR amplified sequences from 49 isolates were digested with AluI, HindIII, MboI or MspI, the resultant patterns were compared between the different isolates and these used to differentiate the isolates from each other. Evidence that the extensive diversity that was found in these genes is the result of reassortment of sequences between strains in the bacterial population is presented, such that a comparatively small number of individual sequence mutations can recombine together in random combinations to form a greater number of distinct alleles. Geographical differences in the predominant patterns in the flaA alleles were also observed and could reflect regional differences either in the human host population or in the bacterial population. In view of the genetic complexity of this species, molecular typing schemes designed to identify related strains may falsely associate strains if the methods do not characterize sufficient genetic sites to exclude chance associations of genetic markers in strains which are actually not closely related to each other.

Extraskeletal osteosarcoma: a clinicopathologic study of four cases

Four cases of extraskeletal osteosarcoma which were treated at the National Cancer Center Hospital have been reviewed. There were three males and one female. The ages of the patients were 32, 48, 48 and 59 years. Three patients had a solitary tumor located in the lower leg, thigh or postirradiated abdominal wall. The remaining patient had multiple tumors in the ipsilateral thigh and buttock. The predominant histologic subtype was osteoblastic in two cases, chondroblastic in one and malignant fibrous histiocytoma-like in one. Only one patient with a subcutaneous tumor was free of disease 16 years after a wide local excision without chemotherapy. The other three patients, two having undergone inadequate initial surgery, and one with multiple tumors, developed pulmonary metastases within 24 months of their initial surgical treatment. All of them died of the pulmonary metastases eight, 36 and 63 months after their initial treatment. Postoperative intensive chemotherapy was given to two patients. Although both had developed metastases to the lung, they received resection of the metastases combined with additional chemotherapy, surviving for more than 24 months after the occurrence of their first metastases.

Specific gravities of desflurane, enflurane, halothane, isoflurane, and sevoflurane

We determined the specific gravities of presently available volatile anesthetics in order to supply a consistent quantitative basis for calibration standards. Using four 50-mL volumetric flasks, we obtained the following values at 20 degrees C: desflurane 1.4651 +/- 0.0004 g/mL (mean +/- SD); enflurane 1.5230 +/- 0.0003 g/mL; halothane 1.8680 +/- 0.0007 g/mL; isoflurane 1.5019 +/- 0.0006 g/mL; and sevoflurane 1.5203 +/- 0.0008 g/mL. Measurements made at 0 degree C, 10 degrees C, 20 degrees C, and 25 degrees C (not for desflurane at 25 degrees C) revealed a decrease in specific gravity of 0.00250 +/- 0.00014 g/mL for each degree of increase in temperature. These data bear on the issue of cost for anesthetics that are stored as liquids, but used as gases.

[The pharmacodynamics of troxipide on experimental gastric ulcers in rats]

Effects of troxipide (Ku-54) on various experimental gastric ulcers in rats were studied. Ku-54 showed a dose-dependent antiulcerous action at 100, 200 and 300 mg/kg (particularly 300 mg/kg) p.o. in water-immersion stress, pylorus ligated and acetic acid reduced rats. The effect of cimetidine (CIM) (600 mg/kg) on water-immersion stress rats was significantly higher than that of Ku-54(300 mg/kg). On the other hand, the effect of Ku-54 (300 mg/kg) was higher than that of CIM (600 mg/kg) on the pylorus ligated and acetic acid reduced groups. The antiulcerous action of Ku-54 (300 mg/kg) was not related with the content and the pH of gastric juice.

Design, synthesis, and neurochemical evaluation of 5-(3-alkyl-1,2,4- oxadiazol-5-yl)-1,4,5,6-tetrahydropyrimidines as M1 muscarinic receptor agonists

A series of 5-(3-alkyl-1,2,4-oxadiazol-5-yl)-1,4,5,6-tetrahydropyrimidines+ ++ (7a-h) was synthesized for biological evaluation as selective agonists for M1 receptors coupled to phosphoinositide (PI) metabolism in the central nervous system. Each ligand bound with high affinity to muscarinic receptors from rat brain as measured by inhibition of [3H]-(R)-quinuclidinyl benzilate ([3H]-(R)-QNB) binding. 5-(3-Methyl-1,2,4-oxadiazol-5-yl)-1,4,5,6-tetrahydropyrimidine+ ++ trifluoroacetate (CDD-0098-J;7a) displayed high affinity (IC50 = 2.7 +/- 0.69 microM) and efficacy at muscarinic receptors coupled to PI metabolism in the rat cortex and hippocampus. Increasing the length of the alkyl substituent increased affinity for muscarinic receptors yet decreased activity in PI turnover assays. The hippocampal PI response of 7a was blocked by lower concentrations of pirenzepine (8) or by higher concentrations of either AF-DX 116 (9) or p-fluorohexahydrosiladifenidol (10), suggesting that at low concentrations 7a selectively stimulates PI turnover through M1 receptors.

[Chemical constituents of Osbeckia chinensis L]

Five constituents, 2-furoic acid, succinic acid, ursolic acid, quercetin and daucosterol were isolated and identified from Osbeckia chinensis. All of them are reported to have been found from this plant for the first time.

[A study on pharmacokinetics of 3H-mitoxantrone in experimental animals]

Mitoxantrone (DHAQ) we studied is a new semisynthetic antitumor drug prepared in China. This paper reports the pharmacokinetic studies of 3H-mitoxantrone in mice by liquid scintillation. The results showed that the decline of radioactivity in the plasma was a biphasic curve after intramuscular and intravenous injection in rats. The adsorption of 3H-DHAQ was ready and complete after intramuscular injection, it was widely distributed in body tissues. The concentration order of various organs was liver greater than intestine greater than kidney greater than lung greater than heart greater than muscles greater than brain. The elimination of the drug was slow, T1/2 was 42.56 h. In 72 h after administration the cumulative excretion of radioactivity in urine was 7% of the total dose, while that in feces was 43%. The main forms of the drug in urine were its metabolites.

[4 mm incision for cataract extraction: a report of 728 eyes]

The author analyzed 728 cataract extractions performed through 4 mm incisions during January 1972 to January 1987. 230 of the operations were done by phaco-emulsification, 320 by lensectomy, and 178 by aspiration. 580 of the eyes were followed up 1-15 years, when 87.8% of the eyes had corrected vision of 0.06 or over, and 48.8% of 0.6 or over. The technical aspect of cataract extraction through a small incision was evaluated and corneal astigmatism thereof discussed.

Observations on the clinical manifestations and treatment of an experimental infection with Brugia malayi in man

This paper reports clinical observations made during experimental Brugia malayi infection in man. This was induced by 52 infective larvae-carrying mosquitoes, Anopheles sinensis. A monkey, Maccaca mulatta, was inoculated with infective larvae from the mosquitoes infected with nocturnally periodic type of B. malayi from patients. Six months later, the monkey became a microfilaria carrier. Nine days later, the subject was experimentally bitten by mosquitoes infected from biting the monkey, with an estimated delivery of over 200 infective larvae. Seven days after the infection, general (but fluctuating) pruritus developed, followed by lymphadenitis and swelling of the hand and forearm, with a mild pyrexia for nearly 3 months. The eosinophil counts continuously increased. There were four separate attacks of lymphangitis. On day 142, microfilaraemia was first detected. After two more weeks, the subject was treated with a total dose of 15 g diethylcarbamazine (DEC) over 30 days. During this period, 28 small tender subcutaneous nodules appeared on his arms. After treatment, microfilaraemia gradually disappeared and the swelling of his arms improved. Three months later, the eosinophil count of his blood returned to normal but some temporary and scattered small pruritic erythematous patches still persisted over his left forearm. Lymphangitis has not recurred.

Formation of lymphocyte colonies under serum-free culture conditions in normal individuals and patients with chronic lymphocytic leukemia

This paper describes a culture system which supports the formation of B cell and some T cell colonies under serum-free conditions in peripheral blood samples of normal individuals and patients with chronic lymphocytic leukemia (CLL) of B cell type. In this system, serum is replaced by bovine serum albumin, transferrin, cholesterol, insulin and catalase or horseradish peroxidase. In addition, it is necessary to add staphylococcus protein A, mitomycin-treated T cells as feeders and phytohemagglutinin leukocyte-conditioned medium as a source of growth factors. The plating efficiency is greatly enhanced when normal cells are incubated with galactose oxidase prior to plating and when CLL cells are exposed sequentially to neuraminidase and galactose oxidase.

Parallel Algorithms for Image Template Matching on Hypercube SIMD Computers

This correspondence presents several parallel algorithms for image template matching on an SIMD array processor with a hypercube interconnection network. For an N by N image and an M by M window, the time complexity is reduced from O(N2M2) for the serial algorithm to O(M2/K2 + M * log2 N/K + log2 N * log2 K) for the N2K2-PE system (1 ¿ K ¿ M), or to O(N2M2/L2) for the L2-PE system (L ¿ N). With efficient use of the inter-PE communication network, each PE requires only a small local memory, many unnecessary data transmissions are eliminated, and the time complexity is greatly reduced.