1.2 Measuring technique for partial hydrogen pressures in nitrogen-neon atmospheres

Gaseous impurities inside the discharge tube of a high pressure metal iodide lamp can have a large influence on the electrical and radiation properties of the lamp. Since the main gaseous impurity is hydrogen this gas must be eliminated from the discharge tube. One way of eliminating this gas is to use a hydrogen gettering material inside the outer bulb of the lamp since, under operational conditions hydrogen can diffuse through the quartz wall of the discharge tube into the outerr bulb.Because most types of high pressure metal iodide lamps have a mixture of a noble gas and nitrogen inside the outer bulb the gettering material must react only with the hydrogen and not with the nitrogen. For this reason the qetter has to be selective. In order to invistigate the selective gettering action of different chemical compounds a simple measuring technique was used to measure continuosly the hydrogen partial pressure inside the nitrogen-noble gas atmosphere.Most investigators use a mass-spectrometer or a gas chromatograph to register the change of the partial hydrogen pressure during the lifetime of the lamp. A much better technique is the use of a nickel diffusion leak combined with a manometer. A higher accuracy can be reached with this methods and it is possible to add or pump away thhe hydrogen without changig the nitrogen or noble gas atmosphere.The selective gettering action of a ZrAl alloys has been examined by this measuring technique and the results of this investigation are given.     

Hemoglobins Aida (alpha 64 Asp leads to Asn) and D-Los Angeles (beta 121 Glu leads to Gln) in an Asian-Indian family

Hemoglobins D-Los Angeles (beta 121 Gln) and Aida (alpha 64 Asn) were encountered in an Asian Indian, unassociated with any clinical manifestations. These hemoglobins had normal oxygen affinities and were stable to heat and isopropanol. The ratio of alpha chain synthesis to beta chain synthesis was close to unity. The identical change in isoelectric points of the two variants produced an interesting electrophoretic pattern.     

Biosynthesis and subcellular localization of histamine in H-110 lymphoma

The histidine decarboxylase activity has been studied in the H-110 Lymphoma implanted in Balb-c mice. The enzymatic activity has been determined using DL-Histidine 1-14C by measuring the I--14CO2 liberated during the incubation. It has been found that the histidine decarboxylase activity in the tumor is the highest of the studied tissues. The pretreatment for 5 days with two cytostatic drugs, cyclophosphamide and 5-fluoruracile, determined a decrease of the enzymatic activity in the tumor of 33 and 54 per cent, respectively. This effect has not been observed in the lung. The pretreatment of the animals during 10 days with 0.1 mg per kg body of histamine, which in other experimental tumors induces an increase of the endogenous content of histamine, produces a decrease of the tumoral histidine decarboxylase activity. The histamine-14C uptake was not modified by this pretreatment. The subcellular localization of the radioactivity after pretreatment with histamine-14C evidenced that the nuclear fraction of the tumor contained between 2 and 10 times the radioactivity of other tissues of the same animal.