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Biomedical subjects

B Webber

Publications and source records attributed to B Webber.

At least 55 records · Page 3Linked to original sources

In vitro synthesis of hemoglobin and hemoglobin chains in the BFUe-derived colonies form person with alpha- or beta-thalassemia.

The synthesis of alpha and non-alpha chains of human hemoglobin (Hb) was studied in reticulocytes and in BFUe-derived cell colonies from patients with alpha chain or beta chain deficiencies. The subjects included normal adults (alpha alpha/alpha alpha) with or without a beta chain variant (Hb S, Hb Leslie) or an alpha chain variant (Hb G-Georgia); alpha-thalassemia-2 heterozygotes (alpha 0 alpha/alpha alpha) with an alpha chain variant (G-Georgia or G-Philadelphia); an alpha-thalassemia-1 heterozygote (alpha 0 alpha 0/alpha alpha); alpha-thalassemia-2 homozygotes (alpha 0 alpha 0/alpha 0 alpha) with a beta chain variant (Hb S), an alpha chain variant (G-Philadelphia), a Hb S homozygosity with Hb G-Philadelphia, or a Hb G-Philadelphia homozygosity; and three black beta +-thalassemia homozygotes. Data from reticulocyte in vitro synthesis analysis showed the expected deficiencies. However, similar analyses of the Hb synthesized in cell colonies (even from the black beta-thalassemia homozygotes) gave (nearly) balanced sigma alpha/sigma non-alpha ratios. It is speculated that this balanced synthesis is due to a most effective proteolysis in the immature erythroblast which rapidly removes free alpha or beta chains. The levels of Hb F and Hb A2 were considerably increased in these proerythroblasts; a two- to threefold increase in the synthesis of Hb A2 was observed over that seen in the reticulocytes.

Adolescent↗

The frequency of the A gamma T gene in the presence and absence of the beta S or beta C gene in the Black population of the Southeastern USA.

Quantitative information about the three types of gamma chains (A gamma T, A gamma I, G gamma) has been obtained for the Hb F from 285 normal Black babies, 172 babies with a Hb S or Hb C heterogeneity, and from 150 babies and older patients with the SS, SC, or CC conditions by means of a high pressure liquid chromatographic microprocedure. The frequency of the A gamma T gene in the AA babies was 0.1035, while that in the SS patients was a low 0.0362. This low A gamma T frequency in the SS population adequately explains the lower percentage (13.2%) of A gamma T heterozygotes among AS newborn babies as compared to 17.9% among AA babies. The genotype with the A gamma T mutant in trans to the beta S mutation is presumed to occur about three times more frequently than that in which the A gamma T mutant is in cis to the beta S mutation. A study of family members of one SS patients who has an A gamma T homozygosity provided data supporting linkage of the A gamma T and beta S anomalies in some Hb S heterozygotes.

Black People↗

Quantitation of three types of gamma chain of HbF by high pressure liquid chromatography; application of this method to the HbF of patients with sickle cell anemia or the S-HPFH condition.

A modification of a high pressure liquid chromatographic (HPLC) procedure is described that enables the complete separation and quantitation of the A gamma T, A gamma I, and G gamma chains in human fetal hemoglobin. The method, which is fast and accurate, requires 5 to 2000 micrograms Hb F. The purity of the Hb F is not essential and admixture of up to 70% adult Hb does not interfere with the determination. The method has been applied to the Hb F of 64 Black SS patients and 7 persons with the Hb S-HPFH (G gamma A gamma type) conditions. (A) Both "adult" G gamma to A gamma (2:3) and "newborn" G gamma to A gamma (3:2) ratios were observed in adult SS patients, 8 yr and older. Only 12% of the SS patients had the "newborn" ratio. This high G gamma to A gamma ratio may be due to a modification of the genetic switch mechanism that regulates the change of this ratio after birth. (B) Intermediate G gamma to A gamma ratios were only found in young SS patients, 5 yr of age or less. The results suggest a delayed switch of the newborn leads to adult ratio in sickle cell anemia. (C) The A gamma T chain was present in only 6% of all SS patients. One patient is homozygous for this variant chain. (D) Three of the 7 subjects with Hb S-HPFH were positive for the A gamma T chain. Its percentage was low, which suggests that the A gamma T chain gene is in trans of the HPFH determinant. (E) Quantitation of the three gamma chain types is also possible in the Hb F from Hb S heterozygotes with (nearly) normal Hb F levels. Such an analysis is useful for an evaluation of genetic conditions involving variations in the production of (different types of) Hb F.

Adolescent↗

The gamma chain heterogeneity of fetal hemoglobin in black beta-thalassemia and HPFH heterozygotes.

High pressure liquid chromatography (HPLC) was applied to the HbF isolated from blood of numerous black patients with beta-thalassemia trait or homozygosity, G gamma-delta beta-thalassemia trait, G gamma A-gamma HPFH heterozygosity, or the G gamma-[delta+ beta+]-HPFH condition. The method allowed an accurate evaluation of the relative quantities of three types of gamma-chain (G gamma, A gamma I, A gamma T) in the fetal hemoglobins. The results have shown the following. (A) The incidence of the A gamma T-chain in beta-thal heterozygotes and G gamma A gamma-HPFH heterozygotes is about the same as has been observed in black newborn; about one of five blacks are heterozygous for this A gamma-chain variant. The A gamma T-chain was not detected in the nine G gamma-delta beta-thal heterozygotes nor in the eight G gamma-[delta+ beta+]-HPFH heterozygotes. (B) In most cases, the A gamma T-chain was produced by the A gamma gene in trans to the beta-thal or HPFH determinant. The contribution by the gamma-chain genes in trans to the beta-thal or HPFH determinant is about 15% of the total gamma-chain production in both conditions. (C) Three black beta-thal heterozygotes (and five additional relatives) had the A gamma T gene in cis to the beta-thal determinant. Four of these patients had a low levels of G gamma-chain (the "adult" level), and the contribution by the A gamma gene in cis to the beta-thal determinant was about three times that of the A gamma gene in trans. The four additional patients, all members of one family, had a high level of G gamma-chain (the "newborn" level), and the contribution of the A gamma gene in cis was half of that seen in the previously mentioned four patients while that of the A gamma gene in trans was essentially the same. These limited data suggest that the genetic anomaly causing high high G gamma levels in adult beta-thal heterozygotes is linked to the beta-thal determinant and that one of its primary effects is a decreased synthetic expression of the A gamma gene in cis to the beta-thal determinant.

Adolescent↗

Adult and fetal hemoglobin production in erythroid colonies from subjects with beta-thalassemia or with hereditary persistance of fetal hemoglobin (HPFH).

The synthesis of alpha and non-alpha chains (beta, delta, G gamma, and A gamma) was studied in cultures of peripheral blood mononuclear cells from eleven beta-thalassemia heterozygotes, two HPFH heterozygotes, and one HPFH homozygote. The synthesis of Hb F in the thalassemia colonies (average value: 12.6%) was comparable to that in normal adult colonies (average value: 12.6%) was comparable to that in normal adult colonies (average value: 12.2%). The percent G gamma chain in the Hb F varied greatly but a relationship between the G gamma chain percentage in the Hb F from colonies and that from peripheral blood was established. The relative synthesis of Hb A2 in colonies of beta-thalassemia heterozygotes (average value: 5.8%) was 1.6 times as much as that in colonies of normal adults (average value: 3.6%). Hb A2 and Hb A were absent in the colonies of the HPFH homozygote. The alpha/non-alpha (i.e., beta, gamma, and delta) ratio of the hemoglobins in the cultured cells of the beta-thalassemia heterozygotes and the alpha/beta and alpha/beta ratios of isolated Hb A and Hb A2 were about one (range 0.74 to 1.38). The alpha/gamma ratio of the Hb F synthesized in BFUe-derived colonies of the HPFH homozygote, however, was 1.5. These results suggest a deficiency in the in vitro culture system resulting in decreased levels of alpha-mRNA or in a partial inhibition of initiation of protein synthesis which is known to reduce the synthesis of alpha chains more than that of the beta chains.

Adult↗

Pulmonary granulomas induced by BCG.

BCG administered by the multiple-puncture technique has been used in a prospective, randomized study of the adjuvant treatment of patients with osteogenic sarcoma. Pulmonary granulomas were found in the lungs of four of five patients receiving BCG, that underwent thoracotomy for the diagnosis of pulmonary nodules within three weeks of the last BCG injection. Except for a single, foreign-body granuloma no pulmonary granulomas were seen in seven randomized patients who did not receive BCG. In addition, two patients receiving BCG had evidence of granulomas in bone marrow and in a mediastinal lymph node. BCG administered by the multiple-puncture technique is capable of causing granulomas at sites distant from that of the BCG application. BCG can cause pulmonary granulomas and these granulomas may be confused with pulmonary metastatic disease.

BCG Vaccine↗

Malignant fibrous histiocytoma (malignant fibrous xanthoma: xanthosarcoma) of bone.

Seven cases of malignant fibrous histiocytoma of bone are documented. In addition to typical histologic features such as the presence of a storiform pattern, histiocytic and fibrocytic cell types and severe cellular atypism, in five cases there were areas in which osteoclast-type giant cells were prominent and the lesion resembled a giant cell tumor. Three of the seven patients developed pulmonary metastases within two years of amputation, one developed extensive local recurrence including soft tissue and vascular invasion, and the other three are without evidence of disease but have been followed for only short periods.

Adolescent↗

A comparison of salbutamol given by pressure-packed aerosol or nebulization via IPPB in acute asthma.

Salbutamol was given by pressure-packed aerosol or nebulizer via IPPB to patients with acute asthma to compare the effectiveness of these methods of inhalation. The results show that both methods produce significant bronchodilatation even in patients admitted with moderately severe asthma (FEV1 about 38% predicted) but a slightly greater improvement may be achieved by IPPB nebulization. Our findings indicate that supervised inhalation of a pressure-packed aerosol of salbutamol may be useful for the initial treatment of asthmatic attacks but confirm the marginal advantage of IPPB nebulization, which should be reserved for patients unable to inhale from a pressure-packed aerosol or failing to respond to its treatment.

Acute Disease↗

Early history of pathology studies by the Intergroup Rhabdomyosarcoma Study Group.

This review chronicles the series of publications that were the result of the willingness of pathologists and clinicians in the United States to share their pathologic materials and clinical data on patients who were placed on treatment protocols for rhabdomyosarcoma and related tumors over an extended period of time. The availability of this database enabled pathologists and clinicians to study a tumor type that is rare in individual institutions, but occurs in large enough numbers to produce valid conclusions not otherwise possible. Furthermore, young investigators were challenged by this opportunity and were able to spend the necessary time to make new observations that, in retrospect, helped direct protocol designs that produced significant improvement in patient survival. The key factor in this process is the surrender of individual scientific prerogatives to a small number of investigators. It is also important to recognize that the pathologist component of these series of contributions is only a part of the entire effort. It takes an organization of gifted, dedicated experts in many disciplines working together. The investigators who served on the Intergroup Rhabdomyosarcoma Group over a 25-year period eminently fulfilled this.

Child↗