Prenatal diagnosis of beta-thalassemia using selective hemolysis of maternal cells contaminating fetal blood sample

The prenatal diagnosis of the severe, hereditary anemias may be impossible when a placental blood sample which contains a high percentage of maternal rather than fetal cells is obtained. An incubation system described by Boyer et al. [3] with minor modifications, was applied to mixtures of blood from prematures and adults in order to increase the proportion of premature cells. After 40 min incubation, 95% or more of adult red cells were destroyed, whereas 30-60% of premature red cells were recovered, as determined by several independent methods. In a pregnancy at risk for beta-thalassemia, a placental blood sample which was purely fetal was obtained. Complete lack of in vitro beta-globin synthesis showed the fetus to have homozygous beta-thalassemia. When fetal blood was mixed with maternal blood in a ratio of 1:15, beta-globin synthesis in the mixture was comparable to that of normal fetuses. In contrast, when the cell mixture was subjected to selective hemolysis prior to separation of globins, beta-globin synthesis again was not detectable. Thus, using selective hemolysis, the correct diagnosis could be established from a blood sample containing only about 6% of fetal cells.

Regulation of photosynthetic electron transport and photophosphorylation in intact chloroplasts and leaves of Spinacia oleracea L

Oxygen ist reduced by the electron transport chain of chloroplasts during CO2 reduction. The rate of electron flow to oxygen is low. Since antimycin A inhibited CO2-dependent oxygen evolution, it is concluded that cyclic photophosphorylation contributes ATP to photosynthesis in chloroplasts which cannot satisfy the ATP requirement of CO2 reduction by electron flow to NADP and to oxygen. Inhibition of photosynthesis by antimycin A was more significant at high than at low light intensities suggesting that cyclic photophosphorylation contributes to photosynthesis particularly at high intensities. Cyclic electron flow in intact chloroplasts is under the control of electron acceptors. At low light intensities or under far-red illumination it is decreased by substrates which accept electrons from photosystem I such as oxaloacetate, nitrite or oxygen. Obviously, the cyclic electron transport pathway is sensitive to electron drainage. In the absence of electron acceptors, cyclic electron flow is supported by far-red illumination and inhibited by red light. The inhibition by light exciting photosystem II demonstrated that the cyclic electron transport pathway is accessible to electrons from photosystem II. Inhibition can be relieved by oxygen which appears to prevent over-reduction of electron carriers of the cyclic pathway and thus has an important regulatory function. The data show that cyclic electron transport is under delicate redox control. Inhibition is caused both by excessive oxidation and by over-reduction of electron carriers of the pathway.

Regulation of photosynthetic electron transport and photophosphorylation in intact chloroplasts and leaves of Spinacia oleracea L

Oxygen ist reduced by the electron transport chain of chloroplasts during CO2 reduction. The rate of electron flow to oxygen is low. Since antimycin A inhibited CO2-dependent oxygen evolution, it is concluded that cyclic photophosphorylation contributes ATP to photosynthesis in chloroplasts which cannot satisfy the ATP requirement of CO2 reduction by electron flow to NADP and to oxygen. Inhibition of photosynthesis by antimycin A was more significant at high than at low light intensities suggesting that cyclic photophosphorylation contributes to photosynthesis particularly at high intensities. Cyclic electron flow in intact chloroplasts is under the control of electron acceptors. At low light intensities or under far-red illumination it is decreased by substrates which accept electrons from photosystem I such as oxaloacetate, nitrite or oxygen. Obviously, the cyclic electron transport pathway is sensitive to electron drainage. In the absence of electron acceptors, cyclic electron flow is supported by far-red illumination and inhibited by red light. The inhibition by light exciting photosystem II demonstrated that the cyclic electron transport pathway is accessible to electrons from photosystem II. Inhibition can be relieved by oxygen which appears to prevent over-reduction of electron carriers of the cyclic pathway and thus has an important regulatory function. The data show that cyclic electron transport is under delicate redox control. Inhibition is caused both by excessive oxidation and by over-reduction of electron carriers of the pathway.

Axillary micrometastasis and macrometastasis in carcinoma of the breast

A retrospective analysis was made of 105 patients with primary operable carcinoma of the breast with positive axillary nodes who had been observed for a 14 year period after radical mastectomy. Patients with micrometastasis alone, especially if only level I is involved, have a good prognosis with 85 and 77 per cent survival rates at ten and 14 years, respectively. No patients had more than three micrometastasis. Patients with four or more positive nodes have a much worse prognosis than do those with three or less positive nodes. Macrometastasis at any level carries a poor prognosis. Since these data show no significant difference between the ten and 14 year survival rates, the ten year survival rate is, therefore, a valid one for long term evaluation of the treatment of carcinoma of the breast.

Morphologic alterations in the parietal yolk-sac of the rat from the 12th to the 19th day of gestation

The rat parietal yolk-sac and its adherent epithelial cells were examined at various stages of gestation using an en face technique. Specimens were observed at both the light and electron microscopic level. Diastase pretreatment and PAS-staining were used to determine the presence of glycogen. As early as the 12th day of gestation the cytoplasm of the parietal yolk-sac cells contained numerous ribosomes and mitochondria and a large amount of endoplasmic reticulum. The glycogen content of the epithelial cells increased from the 12th day of gestation and accumulated in large quantities by the 16th day. By the 17th day many cells exhibited variable degrees of degeneration. Cellular elements of degenerating cells appeared to be trapped within Reichert's membrane. Contrary to the reports of other investigators, the present study indicates that the capsular portion of the parietal yolk-sac consisting of Reichert's membrane and its adherent epithelial cells remained intact until at least the 18th day of gestation. Some of the unique characteristics of the parietal yolk-sac provide experimental models to study the effects of environmental factors on (1) the synthesis of basement membranes, (2) the ageing of cells and (3) the correlation of these histologic changes with the functions of the parietal yolk-sac.

Morphologic alterations in the parietal yolk-sac of the rat from the 12th to the 19th day of gestation

The rat parietal yolk-sac and its adherent epithelial cells were examined at various stages of gestation using an en face technique. Specimens were observed a both the light and electron microscopic level. Diastase pretreatment and PAS-staining were used to determine the presence of glycogen. As early as the 12th day of gestation the cytoplasm of the parietal yolk-sac cells contained numerous ribosomes and mitochondria and a large amount of endoplasmic reticulum. The glycogen content of the epithelial cells increased from the 12th day of gestation and accumulated in large quantities by the 16th day. By the 17th day many cells exhibited variable degrees of degeneration. Cellular elements of degenerating cells appeared to be trapped within Reichert's membrane. Contrary to the reports of other investigators, the present study indicates that the capsular portion of the parietal yolk-sac consisting of Reichert's membrane and its adherent epithelial cells remained intact until at least the 18th day of gestation. Some of the unique characteristics of the parietal yolk-sac provide experimental models to study the effects of environmental factors on (1) the synthesis of basement membranes, (2) the ageing of cells and (3) the correlation of these histologic changes with the functions of the parietal yolk-sac.

[Fetoscopy. A new method in prenatal diagnosis (author's transl)]

Fetoscopes are now being developed which make possible the inspection of human fetuses as well as withdrawal of a fetal blood sample in the early mid-trimester of pregnancy. The preliminary experiences of several groups are presented in this report. In addition, a fetoscopy including fetal blood sampling in a 24 week pregnancy prior to therapeutic abortion is described. The first prenatal diagnoses which have been made using this novel technique, concern defects of the fetal erythrocytes (sickle cel Hb, thalassemia). The fetal blood sample that was obtained in the present case was studied by appropriate methods. As expected, there was no evidence of either of these anomalies.

Hemoglobin chain synthesis in two children with trisomy 13. Evidence for temporary imbalance during switch from gamma to beta chain synthesis

Hemoglobin chain synthesis was studied in 2 infants with trisomy 13, one in the newborn period, the other at 5 months of age. The relative rate of beta globin synthesis was much below normal in the newborn, resulting in an overall imbalance of nonalpha/alpha globin synthesis. In the 5-month-old child, globin synthesis was balanced, although gamma globin synthesis accounted for a larger than normal percentage of nonalpha globin synthesis. Thus, the presence of a third 13 chromosome causes sever disturbances in the gamma to beta switch mechanism primarily affecting the onset of beta globin synthesis. The appearance of two previously unobserved bands in isoelectric focusing gels of the newborn's Hb is suggestive of the presence of embryonic hemoglobins.

The acetylation of hemoglobin by aspirin. In vitro and in vivo

The chemical modification of hemoglobin by aspirin (ASA) has been studied, both in intact human red cells and in purified hemoglobin solutions. After incubation of red cells with 20 mM [acetyl-1minus14C]ASA, incorporation of radioactivity into hemoglobin was observed in agreement with the results of Klotz and Tam (1973. Proc. Natl. Acad. Sci. U. S. A. 70: 1313-1315). In contrast, no labeling of hemoglobin was seen when [carbosyl-14-C]ASA was used. These results indicate that ASA acetylates hemoglobin. The acetylated hemoglobin was readily separated from unmodified hemoglobin by both gel electrofocusing and by column chromatography. Quantitation of the extent of acetylation by densitometric scanning of gels agreed very well with estimates obtained from radioactivity measurements. Hemolysates prepared from red cells incubated with ASA showed normal oxygen affinity and heme-heme interaction. Purified acetylated hemoglobin had a slightly increased oxygen affinity and decreased heme-heme interaction. There was no difference in the rate of acetylation of oxy- and deoxyhemoglobin. ASA acetylated column-purified hemoglobin A more readily than hemoglobin in crude hemolysate, but less rapidly than purified human serum albumin. The rate of acetylation of hemoglobulin increased with pH up to approximately pH 8,5. Structural studies were done on hemoglobin incubated with 2.0 mM and 20 mM [acetyl-1-14-C]ASA. Alpha- and beta-chains were acetylated almost equally. Tryptic digests of purified acetylated subunits were fingerprinted on cellulose thin layer plates and autoradiographed. Both alpha- and beta-chains showed a number of radioactive spots that were either ninhydrin negative or weakly ninhydrin positive. These results indicate that hemoglobin is acetylated at a number of sites, probably at the epislon-amino group of lysine residues. To determine whether ASA acetylates hemoglobin in vivo, hemolysates of 14 patients on long-term high-dose ASA therapy were analyzed by gel electrofocusing and compared to specimens of individuals not receiving ASA. The ASA-treated group had a twofold increase in a minor hemoglobin component having an isoelectric point lower than that of hemoglobin A, and indistinguishable from the minoe component which appears when hemoglobin is incubated with ASA in vitro.

Hemoglobin Syracuse (alpha2beta2-143(H21)His leads to Pro), a new high-affinity variant detected by special electrophoretic methods. Observations on the auto-oxidation of normal and variant hemoglobins

Family members from four generations were found to have polycythemia and increased whole blood O2 affinity (P50; 11 mm Hg; normal, 27 mm Hg). No abnormal hemoglobin bands were seen after electrophoresis on starch gel at pH 8.6 or agar gel at pH 6.0. Analysis of the oxygenated hemolysate by isoelectric focusing on polyacrylamide gel revealed two closely spaced bands. When deoxygenated hemolysate was analyzed in oxygen-free gels, the two components were more widely separated. About 40% of the patient's hemoglobin focused at a more acid pH than hemoglobin A, indicating a hemoglobin variant with impaired Bohr effect. Chromatography of globin in 8 M urea revealed two beta-chain peaks, the first of which was eluted at a lower buffer molarity than normal beta chain. Fingerprints of tryptic digests of the aminoethylated chains were done on silica gel thin-layer plates. Tp 14 from the abnormal beta chain had slower electrophoretic mobility and a greater Rf value. Amino acid analyses of this peptide gave values identical with those of betaTp 14, except that it contained one proline residue and no histidine. Since the one His in betaTp 14 is in position 143, hemoglobin Syracuse in alpha2beta2-143 His leads to Pro. Native Hb Syracuse could be separated from hemoglobin A on a carboxymethylcellulose column. The inclusion of 0.1 mM EDTA in the preparative buffers proved very useful in reducing the formation of methemoglobin. Oxygen equilibria of purified hemoglobin Syracuse showed high oxygen affinity (P50 value 12% that of hemoglobin A) and lack of cooperativity between subunits (Hill's n equals 1.1). The alkaline Bohr effect was about half that of hemoglobin A. The proline substitution at betaH21 disrupts the helical configuration and probably prevents the formation of salt bonds that are important in stabilizing the deoxy structure and contribute to the alkaline Bohr effect. Since beta143 His is a binding site for 2,3-diphosphoglycerate (2,3-DPG), it is not suprising that hemoglobin Syracuse had markedly impaired reactivity with 2,3-DPG. Hemoglobin Syracuse auto-oxidized more slowly than hemoglobin A, probably reflecting a slower rate of dissociation of oxygen from fully liganded hemoglobin.

Effects of cyanate and 2,3-diphosphoglycerate on sickling. Relationship to oxygenation

Cyanate and 2,3-diphosphoglycerate (2,3-DPG) both influence the oxygen affinity of hemoglobin. The studies presented here concern the effects of these compounds on the sickling phenomenon. The inhibitory effect of cyanate on sickling is largely due to the fact that it increases the percentage of oxyhemoglobin S at a given oxygen tension. In addition, cyanate inhibits sickling by a mechanism that is independent of oxygenation. In this paper, we have demonstrated that the viscosity of carbamylated sickle blood was lower than that of non-carbamylated controls at the same oxygen saturation. Furthermore, carbamylation resulted in an increase in the minimum concentration of deoxy-sickle hemoglobin required for gelation. Like cyanate, 2,3-DPG affected sickling of intact erythrocytes by two mechanisms. Since 2,3-DPG decreases the percentage of oxyhemoglobin S at a given oxygen tension, sickling is enhanced. In addition, 2,3-DPG had a direct effect. When the intracellular 2,3-DPG concentration was increased in vitro, a greater percentage of cells were sickled at a given oxygen saturation. Conversely, sickling was inhibited in cells in which 2,3-DPG was artificially lowered. These data indicate that the enhancement of sickling by 2,3-DPG is in part independent of its influence on oxygen affinity.

Beryllium mineralization in the Ilímaussaq intrusion, South Greenland

In the peralkaline Ilimaussaq intrusion in South Greenland minor quantities of beryllium minerals are widespread in hydrothermal veins. Concentrations of veins rich in beryllium minerals are known from the Taseq slope and the Kvanefjeld area in the northern part of the intrusion. Up to now 10 beryllium minerals have been found, the most important being chkalovite. The hydrothermal veins range in width from about 1 mm to 2 m but are mostly a few cm thick. The most important minerals in the veins are analcime, sodalite, ussingite, natrolite, aegirine, arfvedsonite, epistolite and chkalovite. A field beryllometer based on the photoneutron method of determining beryllium is described. With a 100 mCi Sb124 activation source the instrument has a limit of detection ofless than 10 ppm BeO. The effective measuring area is ca. 40 cm2. Beryllium has a log-normal distribution in the rocks of the area.