Myasthenia Gravis: Anesthetic and Surgical Management of the Patient Undergoing Thymectomy

Experience in the anesthetic and surgical management of 25 patients with myasthenia gravis is recorded. These are subdivided into two groups: those operated on during the period 1950-1958 and those operated on during the period 1959-1964. The purpose of this paper is to indicate improvement in mortality and morbidity due to three major advances: (1) use of the decamethonium diagnostic test in a myasthenia gravis clinic; (2) improvements in assessment and management of respiratory insufficiency; and (3) avoidance of anticholinesterase treatment in the immediate and early postoperative recovery period.Fourteen patients with myasthenia gravis, including five with thymoma and two who were refractory to medication, were in the second (1959-1964) group. There were no deaths and no myasthenic or cholinergic crises. Three prophylactic tracheostomies were performed. No emergency bronchoscopies or tracheostomies were required.     

Effect of Desipramine on a Glycoprotein Sialyltransferase Activity in C6 Cultured Glioma Cells

The tricyclic antidepressant desipramine, when added to culture medium, gave rise in C6 rat glioma cells to a decrease of the activity of the enzyme asialofetuin sialyltransferase. The inhibition was dose and time dependent and was observed in both multiplying cells and cells blocked with 2 mM thymidine or depletion of amino acids. This inhibition was rather specific to the sialyltransferase, as under the conditions where this enzyme was inhibited up to 70%, other enzymes such as dolichol phosphate mannose synthetase, glutamine synthetase, and glycerol phosphate dehydrogenase remained unaffected. This inhibition was not reversed after removal of desipramine from the medium and was not observed by direct addition of desipramine to the sialyltransferase incubation assay. Under the same conditions, W-7 [N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide], which is known to be a potent calmodulin antagonist and an inhibitor of calmodulin-dependent kinases, gave the same concentration-dependent inhibition profile of sialyltransferase as desipramine, whereas H-7 [1-(5-isoquinolinylsulfonyl)-2-methylpiperazine], which is an inhibitor of protein kinase C and cyclic nucleotide-dependent kinases, had no effect. So, it is suggested that desipramine inhibits the sialyltransferase activity in C6 glioma cells through a calmodulin-dependent system.     

Efficacy and stability of wettable powder amitraz in field and laboratory studies against Boophilus annulatus (Acari: Ixodidae) in south Texas

A study was done at the USDA-ARS, Cattle Fever Tick Research Laboratory, Mission, Tex., to determine the efficacy of a 50% wettable powder (WP) amitraz formulation applied as a whole-body spray in a standard dip vat, and in a laboratory bioassay against Boophilus annulatus (Say) on cattle. A study also was done at the King Ranch in Kleberg County, Tex., to determine the stability of 50% WP amitraz in a dip vat under South Texas conditions Cattle were infested with all parasitic life stages of B. annulatus and were sprayed or dipped with a concentration of 0.025% amitraz. As determined by calculations of the index of reproduction, the whole-body spray treatment provided 86% control of the ticks and the dip treatment provided 99.8% control. Laboratory bioassay results compared favorably with those obtained with the dip vat treatment. Amitraz WP settled very rapidly in the freshly charged ranch vat. However, as more cattle were dipped and the vat became polluted with dirt and excrement, settling occurred much more slowly. Overall, amitraz remained stable in the vat during the test period.     

Characterisation of a 5-bp deletion in exon 4 of the factor VIII gene: concordance with slipped-mispairing at DNA replication

In an attempt to characterize disease producing mutations in the factor VIII gene we screened exons 4, 7, 8, 11, 12 and 16 by PCR-SSCP (polymerase chain reactionsingle strand conformation polymorphism), in 12 randomly selected haemophilia A patients. These exons were chosen because they have been reported to harbour a disproportionately high number of mutations relative to their size. Using this strategy we detected a frame-shifting 5-bp deletion (TACCT, involving nucleotides 519–523), which is predicted to result in a severely truncated factor VIII polypeptide, terminating approximately midway through the conserved A1 domain and resulting in the observed severe phenotype. We also showed that the sequence in the vicinity of the observed deletion is concordant with the modified slipped-mispairing at DNA replication model of Krawczak and Cooper.     

A study of the flights habits of the European chafer

By using a large cage in the field and a system of marking, the flight activities of 36 females and 49 males of the European chafer were followed during June and July, 1954.It was found that the beetles made one to 11 flights during their life span with males averaging five flights and females 4.5. More males made eight to 11 flights than did females, and males made more flights on consecutive evenings. The average longevity of the males was found to be six days while the females lived on the average for 6.5 days.The main flight period of the European chafer lasts about one month though some beetles can be observed flying in the evenings for about two months after the main flight has ended. The populations observed in the field are composed of successive groups of beetles which emerge, fly for several days then die. These groups overlap each other so that high numbers of beetles are present in the trees each evening during the main flight period. Variations in the physical characteristics of the soil habitat could be responsible for the differences in the time of maturity of the larvae and the subsequent first-time emergence of the adults.

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Zusammenfassung Im Juni und Juli 1954 wurde die Flugtätigkeit von 36 weiblichen und 49 männlichen Tieren von Amphimallon majalis (Razoumowsky) unter Zuhilfenahme eines grossen Käfigs im freien Felde und eines geeigneten Bezeichnungssystems der Tiere verfolgt.Es zeigte sich, dass die Käfer während ihrer Lebensdauer ein bis elf Flüge unternehmen und zwar betrug der Durchschnitt für männliche Tiere fünf, für weibliche 4,5 Flüge. Mehr Männchen als Weibchen flogen 8 bis 11 mal und die Männchen flogen häufiger an aufeinanderfolgenden Abenden. Für männliche Käfer war die durchschnittliche Lebensdauer 6 Tage, während die weiblichen einen Durchschnitt von 6,5 Tagen erreichten.Die Hauptflugperiode von Amphimallon majalis erstreckt sich über etwa einen Monat, obwohl man auch 2 Monate lang nach der Hauptflugzeit des abends noch einige Käfer fliegen sehen kann. Die Gesamtzahl der im Versuchsfeld beobachteten Insekten setzt sich aus auf einander folgenden Gruppen von Käfern zusammen, die nach einander ausschlüpfen, mehrere Tage fliegen und dann sterben. Diese Gruppen überschneiden sich, so dass während der Hauptflugzeit abends eine grosse Anzahl von Käfern in den Bäumen zu finden ist. Es ist sehr wohl möglich, dass Unterschiede in der physikalischen Beschaffenheit des Bodens für die Länge der Reifezeit der Larven verantwortlich sind und somit auch für den Zeitpunkt des Erstfluges der entwickelten Käfer.