Variations in the middle ear of the Mammalia

The comparative morphology of mammalian middle ear structures has been studied by examining the histological sections of the ears of 144 specimens of mammals which had been collected, with a few exceptions, in two expeditions to the Caribbean area. Fifty-four species of six orders of mammals were represented. Sixteen structural features or relationships were specifically studied and the bearing of taxonomic groupings on the variability was analysed.
A taxonometric analysis using these middle ear features indicated that Microdipodops may lie nearer to Dipodomys than to Perognathus.
A table presenting the detailed results has been deposited with the British Museum (Natural History).     

Number of Transformable Units Per Cell in Diplococcus pneumoniae

Analysis of frequencies of single and random multiple transformations in Diplococcus pneumoniae showed that there are at least two transformable units per cell of the total population in highly competent cultures. If 100% of the cells are competent in these cases, the units may be interpreted as the strands of one duplex deoxyribonucleic acid recipient chromosome. The theory is developed to allow for extension to more complex situations.     

Specificity of the Induced Bactericidin of the West Indian Spiny Lobster, Panulirus argus

To investigate the specificity of an inducible hemolymph bactericidin, West Indian spiny lobsters were immunized with a variety of antigens. Bactericidal assays were conducted with strain EMB-1, a gram-negative bacillus isolated from normal lobster intestine. Animals given saline solution with or without 0.3% Formalin exhibited only a slight response similar to sham controls. Injections of type 2 pneumococci or bovine albumin produced slightly higher responses. These were much less pronounced than the homologous response to EMB-1. Formalin exhibited an adjuvant-like effect with EMB-1.     

Effect of Carbon Dioxide on the Aspartic Acid Requirement for Proteinase Biosynthesis by Streptococcus faecalis var. liquefaciens

Non-proliferating cells of Streptococcus faecalis var. liquefaciens required aspartic acid for proteinase biosynthesis in the absence of CO(2) but not in the presence of CO(2).     

Gene products of Amphiuma: An amphibian with an excessive amount of DNA

The nuclei of Amphiuma contain 168 pg of DNA, 28 times that contained in human nuclei. Although many higher organisms appear to possess an excessive amount of DNA, in Amphiuma this has been carried to the extreme. Studies of this organism thus may provide some insight into how this excess DNA is used. This organism presumably evolved by numerous polyploidy and gene duplication events. Do its gene products present multiple electrophoretic forms? Are they quantitatively increased to the same degree as the DNA? Electrophoresis of Amphiuma glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, acid phosphatase, lactic dehydrogenase, and hemoglobin failed to show any evidence for multiple electrophoretic forms of these respective gene products. The amount of hemoglobin, G6PD, and 6PGD per red cell was increased to a comparable or even greater degree than the DNA. Analytical ultracentrifugation demonstrated a satellite band of DNA with a density of 1.720 corresponding to a GC content of 61%. This probably represents DNA coding for ribosomal RNA. Electron microscopy of liver nuclei showed a significant amount of condensed chromatin. The implications of these observations are discussed.     

Effects of anhydrous benzoylation on staining with a variety of protein end-group methods

Summary The effects of anhydrous benzoylation were examined in connection with the following protein end-group methods: diazosulfanilic acid — Azure A, the Sakaguchi reaction and a fluorescent variant, the phenanthrequinone fluorescent method for arginine, the Millon reaction, the Morel-Sisley reaction, the mercury orange method, the alloxan and ninhydrinShiff methods, the Dansyl-chloride fluorescent method for lysine, the dimethylaminobenz-aldehydenitrite (DMAB) method for tryptophan, and the acid fluorochrome brilliant sulfoflavin used at pH 2.8 as a stain for basic groups. With all of these methods except the DMAB method for tryptophan, selective blockage of cytoplasmic proteins and staining of nuclei was obtained. With the DMAB reaction, the results were reversed: cytoplasmic staining exceeded nuclear staining after benzoylation.     

Combination Chemotherapy using L-Asparaginase,Daunorubicin, and Cytosine Arabinoside in Adults with Acute Myelogenous Leukaemia

Cytosine arabinoside and daunorubicin used in an intensive intermittent regimen have been shown to be an effective combination for the induction of complete remissions in 14 out of 23 adult patients with acute myelogenous leukaemia. This gives an overall complete remission rate of 60%. A further patient had a good partial remission. The addition of L-asparaginase to the regimen has not increased the incidence of remission and there were more side effects in the L-asparaginasetreated group. Of the 10 patients treated with L-asparaginase in addition to cytosine arabinoside and daunorubicin, five achieved a complete remission. Of the 13 patients treated with cytosine arabinoside and daunorubicin without L-asparaginase, nine achieved a complete remission and one a good partial remission.     

PRENATAL CARE—A Group Psychotherapeutic Approach

It has been well established that “normal” pregnancy gives rise to much anxiety whose source is variable. When not adequately dealt with, the anxiety may masquerade in the guise of physical symptoms such as fatigue, dizziness, nausea and vomiting, or, more often, as disquieting emotional counterparts, like irritability and depression.A study was undertaken in the outpatient obstetrical department at U.C.L.A. utilizing a group psychotherapeutic approach. The results helped the patients and offered training to staff in dealing with emotional problems of pregnancy. Patients were seen in groups of seven, twice a month for one-hour sessions. Participating in each group were an obstetrical resident, a psychiatric resident and a nurse. The subject material was not selected beforehand. Groups were similar in that the expected time of delivery of the patients was approximately the same. Results of the study suggested that the much needed emotional support may be supplied in this way with little to no additional time expenditure on the part of the physician or nurse.     

Morphology of a Virus of Blue-green Algae and Properties of Its Deoxyribonucleic Acid

The morphology of Safferman's virus of blue-green algae (phycovirus LPP-1) has been studied by electron microscopy and physicochemical methods. The virion has a short (100 to 200 A long, 150 A in diameter) forked tail, with an outer sheath, an inner core, and a capital attached to one of the vertices of a polyhedral head. The head capsid edge-to-edge distance is 600 A, based upon internal calibration of the magnification in electron micrographs by use of the line-line spacing of catalase crystals. Measurements of absorbancy and infectivity, and electron microscopy across the band of virus after zone centrifugation on a sucrose gradient, indicated that infectivity was correlated with the short-tailed particles described. The viral deoxyribonucleic acid (DNA) is linear, with a contour length of 13.2 +/- 0.5 mu, measured by the Kleinschmidt method. Its sedimentation coefficient, S(0) (20, w), is 33.4 +/- 0.7 S. These values are consistent with a molecular weight of 27 x 10(6) for the viral DNA. Based upon buoyant density in CsCl and thermal denaturation, the guanine-cytosine content of the DNA is 53%. The viral DNA was used as template for in vitro ribonucleic acid (RNA) synthesis by Escherichia coli RNA polymerase. This RNA annealed to 18% of the sequences in the viral DNA, 0.5% of the sequences in bacteriophage T7 DNA, and 0.25% of the sequences in Plectonema boryanum DNA, at saturating levels of RNA in the Hall-Nygaard hybridization assay. The lack of homology with T7 DNA is of interest because the two viruses are very similar morphologically. The lack of homology with host DNA suggests that this algal virus is a poor candidate for transduction.