A near haploid clone: 24,XY, t (9; 22) (q34; q11) from a patient in blast crisis of chronic myeloid leukaemia

Chromosome studies on bone marrow in a patient with chronic myeloid leukaemia (CML) revealed a mosaic picture with a dominant clone of 24,XY, t(9; 22) (q34; q11). This corresponded to a preponderance of minute blasts in smears of bone marrow aspirate. It is suggested that a haploidy event rather than progressive hypodiploid loss, is responsible for the genesis of the miniature blast cells.

The relationships among arterial oxygen flow rate, oxygen binding by hemoglobin, and oxygen utilization in chronic cardiac decompensation

We have examined the interrelationships among CaO2, blood flow, oxygen binding by hemoglobin, and VO2 in cardiac patients with and without chronic cardiac decompensation. We have quantified the role that decreased oxygen-binding to hemoglobin may play in maintaining VO2 in the presence of low systemic blood flow rates. The volume rate of oxygen delivery to tissues was expressed as the OFIa, the product of CO2 and blood flow. OFIa varied from 738 to 262 ml/min/m2, whereas VO2 varied from 170 to 117 ml/min/m2. Thus, in the patients with lowest OFIa (63% below the highest OFIa), VO2 was only down 19%. VO2 was maintained because the extraction of oxygen rose from about 20% to 50% in close association with the decrease in OFIa. Oxygen binding to hemoglobin was lower in patients with the lowest OFIa--and therefore, at in vivo conditions of pH, PCO2, and temperature, P50 in vivo was higher. The resulting facilitation of oxygen release at the PO2 of tissue capillaries could explain about one third of the observed increment in oxygen extraction in patients with low OFIa. An alternative interpretation is that a high P50 in vivo minimizes the reduction in PVO2 needed to maintain VO2 when increased proportional extraction of O2 compensates for decreased OFIa.

[Incisions in oral surgery]

Oral mucosa incision can allow several interventions: cellulitis or periodontal abscess opening, gingival tissue excision or repositioning or at least exposure of alveolar bone for tooth extraction or infrabony pockets' treatment. The different incisions are described with special considerations: --on the anatomic environment of the oral cavity (palatal arteries, mandibular nerve...)--on the healing patterns of the different periodontal tissues (rapid cellular turnover of the epithelial attachment for instance)--at last on the suturing for each intervention. The instrumentation needed for the different incisions is described and clinical cases are presented before, during and after oral surgery. The use of an electrical knife is noted with the contraindications of this operative procedure.

[Adenine nucleotide- and 2,3-diphosphoglycerate metabolism in human erythrocytes in chronic kidney insufficiency]

In 38 patients with chronic renal insufficiency of different degree of severity examinations of the stationary concentration of the adenine nucleotides in the erythrocytes were carried out. It was shown that in the red blood cells of uraemics a genuine increase of the concentration of these compounds occurs, in which case the adenosine triphosphate dominates absolutely as well as relatively. In individual cases erytho-cyctic ATP-values of more than 3 micron mol pro ml cells may be achieved. The increase of the ATP-concentration in the red blood cells correlates with the degree of severity of the renal insufficiency and the renal anaemia. The hyperphosphataemia occurring as a rule in renal insuficiency is of causal importance for the increase of ATP. By a consecutive increase of the intracellular phosphate level and by influence on different steps of enzymes (phosphofructokinase, aldolase, glycerin aldehyde phosphate dehydrogenase) and changed regulations it effected an activation of the glycolysis. The increase of the plasma adenine and plasma adenosine concentration plays apparantly an accessory role for the increase of the concentration of the adenine nucleotides existing in the erythrocytes. Together with an increased concentration of 2,3-diphosphogycerate (2,3-DPG) the increase of the ATP-level has an effect on the oxygen transport function function of haemoglobin in the sense of a facilitation of the O2-output. These processes explain the relative adaption of patients with chronic renal insufficiency to renal anaemias of partly high degree.

Structure and inheritance of some heterozygous Robertsonian translocation in man

Banding studies in 25 Robertsonian translocations showed that all could be interpreted as stable dicentrics. The mechanism for their stability is likely to be the proximity of their centromeres but centromeric suppression could also have a role. In many of these dicentric translocations, discontinuous centromeric suppression, as indicated by chromatid separation at one of the centromeric regions, was observed in C-banded preparations. A further observation of undefined relation to the first was that the ratio of the two constitutive centromeric heterochromatin (CCH) regions from the component chromosomes of the translocations was variable in the same translocation type, e.g. t(13;14). It is proposed that this ratio may influence the segregation ratio. Abnormal spermatogenesis is suggested as the likely mechanism for the difference in the proportion of aneuploid offspring in the progeny of maternal and paternal heterozygotes. Neither of the t dic(21;21)s could be interpreted as isochromosomes. It is proposed that Robertsonian fusion translocations be defined as stable, dicentric, whole-arm translocations, with both centromeres in a median position and resulting in the loss of a small acentric fragment during this formation. It is suggested that they occur at high frequency between telocentric or, as in man, certain acrocentric chromosomes because of some intrinsic property of those chromosomes not possessed by metacentric chromosomes and mediated by interphase association of centromeres.