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Biomedical subjects

M Kaku

Publications and source records attributed to M Kaku.

At least 199 records · Page 11Linked to original sources

Children in Juba, southern Sudan: the second and third years of life.

A prospective study of child health has been continued until the children were 36 months old. The mortality rate in the second year was 8.1%. The most common cause of death was chronic undernutrition. The 79 children suffered seventy-six episodes of faltering weight gain; 47 lost 0.5 kg, and most did not reach their former weight for 5 months. Marasmus complicated eighteen faltering episodes; three were fatal. Of 45 children remaining in Juba to their 36th month none had marasmus, and their health was improved. 15 of 53 children, mean age 2.25 years, showed developmental delay. After 10 months 7 showed continued delay. Hepatitis B seemed to be transmitted to the children from both mothers and other sources. Day-care centres can help chronically undernourished children, and health education should be directed towards the parents' capabilities.

Body Height↗

Abolishment of inhibitory effects of 3'-deazaadenosine on superoxide generation of guinea pig phagocytes by pre-exposure to phorbol myristate acetate.

Superoxide generation by guinea pig macrophages and polymorphonuclear leukocytes induced by wheat germ agglutinin, immune complexes or formyl-methionyl-leucyl-phenylalanine was inhibited considerably by 3'-deazaadenosine. The pre-exposure of the 3'-dezazaadenosine-treated cells to a small amount of phorbol myristate acetate abolished the inhibitory effect of 3'-deazaadenosine on the generation of superoxide.

Animals↗

Enlargement of a cerebral aneurysm associated with ruptured arteriovenous malformation.

Enlargement of a small aneurysm during an eleven year period was encountered in a 32-year-old man who had experienced intracranial haemorrhage from a distally located AVM. Clipping of the feeding artery together with the aneurysmal neck was performed. It was very rare to observe the aneurysmal growth associated with the AVM. This case was considered worth reporting as supporting evidence that hemodynamic stress plays an important role in the development of an aneurysm.

Adult↗

Study on abnormalities in the appearance of finger and palm prints in children with cleft lip, alveolus, and palate.

The aetiology of abnormalities in the appearance of finger and palm prints in children with cleft lip, alveolus, and palate was examined by comparing the frequencies of abnormalities in hereditary cases and sporadic cases, and those in hereditary cases with those in their parents. The following results were obtained: Comparison of hereditary cases and sporadic cases. Abnormalities in the appearance of finger and palm prints were greater in hereditary cases than in sporadic cases. Abnormalities in the appearance of finger and palm prints were greater in parents of hereditary cases than in parents of sporadic cases. The rate of agreement in the appearance of finger and palm prints between parents and children was greater in hereditary cases than in sporadic cases. Comparison within hereditary cases. Abnormalities in the appearance of finger and palm prints were greater in affected children when one of the parents was affected (gamma = 1/2) than when both parents were normal (gamma = less than 1/2). Abnormalities in the appearance of finger and palm prints were greater in parents, one of whom was affected, than in normal parents. The rate of agreement in the appearance of finger and palm prints of parents, one of whom was affected, and their gamma = 1/2 children cases was higher than of normal parents and their gamma = less than 1/2 children. It was concluded that the above results could be explained by multifactorial inheritance.

Adolescent↗

Effect of peroxisomal proliferators on microsomal prostaglandin A omega-hydroxylase.

Earlier, we reported the isolation of a cytochrome P-450 highly active in prostaglandin A (PGA) omega-hydroxylation (PGA omega-hydroxylase) from rabbit kidney cortex, small intestine, and colon microsomes. In the present studies, the effects of peroxisomal proliferating agents on the PGA omega-hydroxylase have been examined. Administration of clofibrate or di(2-ethylhexyl)phthalate (DEHP) resulted in a significant increase in the PGA1 omega-hydroxylase activity of kidney cortex, liver, and small intestine microsomes. Similar findings were also obtained for laurate hydroxylase activity in kidney and liver microsomes. Kidney PGA omega-hydroxylase (designated cytochrome P-450ka) was isolated and highly purified from clofibrate- or DEHP-treated rabbits, with a yield 3 times higher than that from untreated, or phenobarbital- or 3-methylcholanthrene-treated rabbits. Cytochrome P-450ka from clofibrate- or DEHP-treated rabbits exhibited the same properties as those from untreated rabbits. Guinea pig antiserum against cytochrome P-450ka strongly inhibited the omega-hydroxylation of PGA1 by kidney cortex microsomes from clofibrate-treated rabbits. The PGA1 omega-hydroxylase activity of clofibrate-treated liver microsomes was also inhibited by this antiserum, suggesting that a PGA omega-hydroxylase immunochemically related to cytochrome P-450ka exists in liver microsomes.

Animals↗

Rapid identification of Klebsiella pneumoniae in the lung tissue by fluorescence microscopy.

Klebsiella pneumoniae is stained weekly with hematoxylin and eosin, moderately with periodic acid Schiff (PAS), and strongly by the Warthin-Starry method. Staining by the Warthin-Starry method, however, takes more than one hour. Therefore, we developed a new procedure for rapid identification of K. pneumoniae in paraffin sections of the lung under a fluorescence microscope.

Animals↗

Separation of two constitutive forms of cytochrome P-450 active in aminopyrine N-demethylation from rabbit intestinal mucosa microsomes.

Two constitutive forms of cytochrome P-450, designated P-450ib and P-450ic, were purified from intestinal mucosa microsomes of untreated rabbits. P-450ib and P-450ic have minimal molecular weights of 56 000 and 49 000, respectively, as determined by calibrated sodium dodecyl sulphate polyacrylamide gel electrophoresis. The CO-reduced difference spectral maximum of cytochrome P-450ib is at 450 nm and P-450ic is at 451 nm. Both the cytochromes preferentially demethylate aminopyrine, benzphetamine and N,N-dimethylaniline in the presence of NADPH-cytochrome P-450 reductase. Cytochrome P-450ib has absorption maxima at 417, 535 and 573 nm in the oxidized form, indicating that this cytochrome is in a low-spin state. Ouchterlony double-diffusion studies show that cytochrome P-450ib does not cross-react with antisera against liver cytochrome P-450LM2 purified from phenobarbital-treated rabbits, but P-450ic cross-reacts with spur formation. Unlike cytochrome P-450ib, P-450ic is very similar, if not identical, to liver cytochrome P-450LM2 on the basis of its molecular weight, spectral properties, catalytic activities and immunochemical properties.

Aminopyrine N-Demethylase↗

Phenazine methosulfate stimulation of ouabain-sensitive Rb+ uptake by HeLa cells: effects of respiratory inhibitors, anaerobiosis, and ascorbate.

phenazine methosulfate (PMS) stimulates ouabain-sensitive Rb+ uptake by HeLa cells. This stimulation cannot be attributed to the effect of the dye on the intracellular Na+ or ATP content. Respiratory inhibitors, such as 5 mM NaCN and 5 microM rotenone, and anaerobic conditions enhance the stimulation of Rb+ uptake by PMS. Cellular respiration is stimulated, but lactate production is reduced in the presence of PMS, irrespective of the presence of respiratory inhibitors. Cellular NADH is oxidized markedly on addition of PMS plus inhibitors, but it is not affected by addition of the inhibitors only. In the presence of a high concentration of PMS, PMS-stimulated ouabain-sensitive Rb+ uptake is inhibited by addition of ascorbate. From these results it is concluded that Na+K-pump activity is closely related to the cellular redox state.

Adenosine Triphosphate↗

In vitro differentiation of a human erythroid cell line (KMOE) induced by some metabolic inhibitors.

KMOE-2/05, a continuous human erythroid cell line derived from a patient with acute erythremia was capable of differentiating into benzidine positive cells following exposure to cytosine arabinoside (CA), mitomycin C, or daunorubicin. Among the three substances, CA was the most effective inducer. Other compounds, reported as effective inducers on human and murine erythroid cells, were also tested but they were ineffective. Benzidine positive cells were counted to be approximately 500/1 X 10(5) cells after 10 days incubation with CA at its optimal concentration of 1 X 10(-5) M. Under the same conditions, the hemoglobin (Hb) concentration quantitated by radioimmunoassay (RIA) was more than 500 ng/1 X 10(6) cells. Quantitative kinetics of synthesized Hb and of benzidine-positive cell counts, after exposure to CA were closely correlated.

Antimetabolites↗

Syringomyelia associated with a foramen magnum meningioma.

In a 14-year-old boy with a meningioma at the foramen magnum extending to C-2, cervical syringomyelia was found on metrizamide computed tomographic myelography. The mechanism of syrinx enhancement on delayed computed tomographic scanning was considered to be due to transneural passage of metrizamide into the spinal cord. Long-standing spinal block may be responsible for development of syringomyelia. Syringomyelia associated with spinal extramedullary tumors was reviewed in the literature.

Adolescent↗

Superoxide anion generation by polymorphonuclear leukocytes enhanced in a patient with colony-stimulating activity-producing lung cancer.

We examined superoxide (O-2)-generating activity of polymorphonuclear leukocytes (PMN) from a patient with lung cancer in whom there was a marked granulocytosis. There was a high level of colony-stimulating activity (CSA) in both the serum and the supernatant of the culture of the primary tumor. The PMN from the patient produced almost three times more O-2 than did the PMN from healthy donors and other patients with lung cancers but with no granulocytosis. The binding of wheat germ agglutinin (WGA), used as a stimulus for O-2 generation, to the surface membrane of cells and the protein content in the cells were about double that noted in the case of healthy donors. Following total extirpation of the tumor, the level of CSA in the serum decreased, as did activity of PMN for O-2 generation, and the binding of WGA to the cells reverted to normal levels.

Blood Proteins↗

Multiple forms of cytochrome P-450 in rabbit colon microsomes.

Three cytochrome P-450 preparations, designated as cytochrome P-450ca, cytochrome P-450cb, and cytochrome P-448c fraction, were separated and purified about 23-, 50-, and 29-fold, respectively, from the cholate extracts of rabbit colon mucosa microsomes. Their specific contents were 1.2, 2.6, and 1.5 nmol of cytochrome P-450 per mg of protein, respectively. Cytochrome P-450ca and cytochrome P-450cb migrated as heme-containing polypeptide bands with molecular weights of about 53,000 and 57,000, respectively, on SDS-polyacrylamide gel electrophoresis. The CO-reduced difference spectra of cytochrome P-450ca, cytochrome P-450cb, and cytochrome P-448c fraction showed maxima at 451, 450, and 449 nm, respectively. Cytochrome P-450ca efficiently catalyzed the omega-hydroxylation of prostaglandin A1 (PGA1) and the omega- and (omega-1)-hydroxylation of caprate, laurate, and myristate in the reconstituted system containing cytochrome P-450ca, NADPH-cytochrome P-450 reductase, cytochrome b5, and phosphatidylcholine. In contrast, cytochrome P-450cb and cytochrome P-448c fraction had no detectable activity toward PGA1 and fatty acids. Both catalyzed aminopyrine and benzphetamine N-demethylation. Cytochrome P-448c fraction also hydroxylated benzo(a)pyrene, and phosphatidylinositol or phosphatidylserine exhibited a stimulatory effect on this activity. The results show that rabbit colon microsomes contain catalytically different cytochrome P-450, one of which is specialized for the omega-oxidation prostaglandins, the others being involved in the metabolism of exogenous compounds such as drugs and polycyclic hydrocarbons.

Animals↗

Down-regulation of Fc receptor expression in guinea pig peritoneal exudate macrophages by muramyl dipeptide or lipopolysaccharide.

Expression of Fc receptors on the plasma membrane of guinea pig peritoneal exudate macrophages (PEM) was suppressed to almost one-half of that of the controls by long-term exposure to lipopolysaccharide (LPS) or muramyl dipeptide (MDP) in culture. The effect of the reagents was dose and time dependent, and as little as 0.5 ng/ml LPS or 5 ng/ml MDP was effective for the suppression. The expression of the Fc receptors decreased to 60 to 70% of the control level at 48 hr and to 45 to 50% at 72 hr after incubation of the cells in the presence of LPS or MDP. A Scatchard plot of the binding of 125I-soluble immune complexes (I.C.) to the cells revealed that the decrease in the binding of 125I-I.C. is due to a reduction in the number of Fc receptors on the cell membrane and not to a decreased affinity of the receptors. The membrane protein was radio-labeled with 125I, and the Fc receptors were purified by being bound to insoluble I.C. The specific binding of the 125I-labeled Fc receptors, from the LPS-treated macrophages, to the insoluble I.C. was almost one-half of that from the untreated control cells. SDS-PAGE analysis of the purified 125I-labeled Fc receptors revealed that the major peak of the m.w. 44,000 molecule in the LPS-treated cells was almost one-half of that of the control. Contrary to the effect of LPS or MDP, 72-hr incubation of macrophages with MIF-rich supernatant, cultured from lymph node cells, enhanced the expression of Fc receptors. Macrophages were treated with I.C. for 4 hr at 37 degrees C to remove the Fc receptors from the surface membrane. The reappearance of the receptors on the plasma membrane of the cells was significantly suppressed by LPS and MDP. The effect of LPS on the binding of five murine monoclonal antibodies (Ab) raised against PEM to the macrophage membrane and also that of 125I-wheat germ agglutinin (WGA) or 125I-insulin was studied. The monoclonal Ab were selected for their activity to induce superoxide anion generation in the macrophages, as do I.C., although the binding sites for the monoclonal Ab were not related to Fc receptors. The bindings of the five monoclonal Ab were not affected by exposure of the cells to LPS or MDP. Macrophages treated with the reagents bound as much 125I-insulin or WGA as did the untreated control cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetylmuramyl-Alanyl-Isoglutamine↗

Characterization of three monoclonal antibodies which induce and modulate superoxide anion generation in guinea pig macrophages.

Three monoclonal antibodies (Ab), termed KY 12, KY 22, and KY 25 and raised against guinea pig macrophages, induced superoxide anion (O2-) generation in the cells. Although each monoclonal Ab bound to macrophages, each had a different pattern of binding to other cell types. In response to each of the Ab, the amount of O2- generated by 5 X 10(5) macrophages was between 0.5 and 0.7 nmol/min and was augmented threefold to fivefold by the addition of F(ab')2 fragments of rabbit Abs to mouse Ig. When macrophages were pretreated with soluble immune complexes (I.C.) prior to stimulation by the monoclonal Ab, the O2- generation stimulated by KY 12 or KY 22 was reduced by more than 70%. In contrast, pretreatment of macrophages with I.C. did not reduce O2- generation in response to KY 25. KY 12 and KY 22 stimulated adenyl cyclase activity in macrophages, but KY 25 did not. Pretreatment of the cells with soluble I.C. did not interfere with the enhancing effect of the monoclonal Ab on adenyl cyclase activity. Pretreatment of macrophages with KY 12 reduced by over 60% of subsequent generation of O2- in response to wheat germ agglutinin, I.C., formyl-methionyl-leucyl-phenylalanine, phorbol myristate acetate, KY 22, or KY 25. KY 22 or KY 25 did not suppress the generation of O2- in response to other stimuli. These results suggest that KY 22 and KY 25 activate O2- generation in a manner that differs from that of KY 12. These monoclonal Ab should prove useful in examining the regulation of O2- production.

Adenylyl Cyclases↗

Fc receptor-mediated desensitization of superoxide (O2-) generation response of guinea-pig macrophages and polymorphonuclear leucocytes.

Guinea-pig macrophages were pretreated with soluble immune complexes (1 hr, at 37 degrees). By this procedure, the capacity of the cells to produce superoxide anions (O2-) upon stimulation with wheatgerm agglutinin (WGA) was inhibited by as much as 80% (desensitization). However, the receptors for WGA were still available on the cell surfaces as determined by the binding of 125I-labelled WGA to both the pretreated and control cells. This inhibition of O2- generation was also observed when opsonized zymosan (Op-zymosan) was used as the stimulus for O2- generation. In contrast, the inhibition by soluble immune complexes was less than 25% of the control levels when the desensitized cells were stimulated with N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP) or phorbol myristate acetate (PMA). The same procedure was also used to desensitize guinea-pig polymorphonuclear leucocytes (PMN). In this case, the O2- generation of the PMN was suppressed to 50-55% of the control level when WGA or fMLP was used as stimulus. However, the PMA-induced O2- generation was far less affected by this treatment, as was the case with the macrophages. The activity of the desensitized macrophages for O2- generation recovered gradually to a normal level 24 hr after removal of the immune complexes from the medium. These results suggest that (i) some regulatory mechanisms which suppress the activation of NADPH oxidase are accentuated by prolonged exposure of guinea-pig macrophages and PMN with soluble immune complexes; (ii) the mechanism for O2- generation mediated by WGA or Op-zymosan may be different from that for O2- generation mediated by PMA, and (iii) the mechanism for O2- generation mediated by fMLP differs between macrophages and PMN.

Animals↗