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Biomedical subjects

R L Baehner

Publications and source records attributed to R L Baehner.

At least 19 recordsLinked to original sources
PubMed1979

Enhancement of chemotactic response and microtubule assembly in human leukocytes by ascorbic acid.

The incubation of human leukocytes with ascorbic acid increased chemotaxis of the cells. In addition, ascorbic acid promoted the assembly of intracellular polymorphonuclear leukocyte (PMN) with colchicine blocked the effect of ascorbic acid on promoting microtubule assembly. Not only did ascorbic acid promote the assembly of microtubules in vivo, but it enhanced the assembly of bovine brain tubulin into microtubules in vitro as quantitated by a glass-fiber filtration assay and by promotion of viscosity changes. The enhancement in leukocyte mobility by ascorbate at concentrations achievable in normal tissues correlates with its ability to assemble microtubule organelles.

Ascorbic Acid↗
PubMed1979

Improved remission induction rate with D-ZAPO but unimproved remission duration with addition of immunotherapy to chemotherapy in previously untreated children with ANLL.

In 163 children with acute nonlymphocytic leukemia (ANLL), a D-ZAPO induction program consisting of daunomycin, 5-azacytidine, cytosine arabinoside, prednisone, and vincristine resulted in a remission rate of 71.8%. Immunologic therapy was employed during maintenance with the aim of prolonging remission and improving survival. The administration of immunotherapy consisting of a mixture of bacillus Calmette-Guérin (BCG) and allogenic acute myelomonocytic leukemic cells injected intradermally on day 14 of each of the first three monthly cycles of 6-thioguanine for ten days, 5-azacytidine and cytosine arabinoside for four days, and vincristine for one day did not improve remission duration or survival compared to that due to chemotherapy alone. Important prognostic factors identified in this study included a remission induction rate significantly better for females than males (P = 0.04), for children between the ages of 5 and 10 years compared to those greater than this age group (P = 0.01), and a prolonged remission duration (P = 0.04), and survival (P less than 0.01) for patients with initial white blood counts of less than 20 x 10(9)/liter.

Adolescent↗
PubMed1979

Acute myeloblastic leukemia two years after diagnosis of non-Hodgkin lymphoma.

The 18-year-old white male developed acute myeloblastic leukemia (AML) 25 months after diagnosis of poorly differentiated lymphocytic lymphoma, diffuse pattern (PDLL-D), involving cervical, supraclavicular, and mediastinal lymph nodes as well as bone marrow. Treatment of the lymphoma consisted of 2,000 rads to the mantel area and 18 months of chemotherapy with intravenous (IV) methotrexate (400 mg/m2), vincristine, and prednisone, alternating every two weeks with IV cyclophosphamide (1,000 mg/m2), vincristine, and prednisone plus monthly intrathecal methotrexate. Thereafter, a complete remission was maintained without therapy until the onset of AML. Several pseudodiploid clones containing multiple structural rearrangements and a hypodiploid clone were identified in the circulating blood at the time of diagnosis of AML. Induction therapy consisting of cytosine arabinoside, 5-azacytidine, vincristine, and prednisone was unsuccessful, and the patient died of sepsis two months after diagnosis. This case calls attention to the increased risk for subsequent acute nonlymphocytic leukemia in patients previously treated for nonhodgkin lymphoma.

Adolescent↗
PubMed1979

Sister chromatid exchange in lymphocytes from patients with acute lymphoblastic leukemia.

Sister chromatid exchange (SCE) frequencies were studied in peripheral lymphocytes from 16 patients with newly diagnosed acute lymphoblastic leukemia (ALL) prior to the initiation of chemotherapy. The mean SCE frequency (mean +/- SE) for these patients was 12.2 +/- 0.2 per metaphase, which was significantly higher (P less than 0.001) than the mean SCE score for 14 age-matched controls, 7.6 +/- 0.2. Five of these patients were studied again while they were receiving maintenance therapy consisting primarily of daily 6-mercaptopurine and weekly methotrexate. Their remission SCE levels remained significantly higher than controls (P less than 0.005). In addition, SCE levels were studied in 7 long-term survivors of ALL. Three of these patients had been receiving continuous maintenance therapy for at least 3 years. Their mean SCE scores were significantly greater than controls (P less than 0.005). The other 4 patients had finished their final course of chemotherapy at least 8 months prior to the time of sampling, and their mean SCE scores were not significantly different from controls (P greater than 0.10). These data indicate that untreated patients with ALL have increased SCE levels which remain elevated during periods of remission maintained with chemotherapy. However, long-term survivors of ALL who are in remission and off chemotherapy do not demonstrate significantly increased SCE frequencies.

Adolescent↗
PubMed1979

Septicemia in association with acute lymphoblastic leukemia.

Fifty consecutive episodes of septicemia were studied in 41 children who had acute lymphoblastic leukemia. Seventy-six percent of these episodes occurred when the absolute granulocyte count was 200/mm3 or less and were caused by gram-negative enteric and gram-positive mucocutaneous bacteria. In eight patients, Streptococcus pyogenes was isolated at the time when ALL was diagnosed. Multiple anaerobic and aerobic isolates from a single blood culture were associated with abdominal distress, whereas Streptococcus pneumoniae and Hemophilus influenzae septicemia occurred in associated with respiratory illnesses. When patients with severe compromise of anatomic barriers or respiratory disease were excluded, 94% of all patients with septicemia had an AGC of less than 200/mm3. The data provide guidelines for treatment for febrile patients with ALL based upon the AGC, the phase of the disease, and on the presence of associated respiratory or abdominal findings.

Acute Disease↗
PubMed1979

Reversal of protein-energy malnutrition in children during treatment of advanced neoplastic disease.

The effectiveness of enteral and parenteral feeding in supporting a satisfactory nutritional status and/or reversing protein-energy malnutrition was evaluated in 28 children, ages 1-19 (14 female) with advanced malignant disease (21 solid tumors, 7 leukemia-lymphoma). At the onset of treatment, 21 patients received intensive nutritional counseling (INC) and oral supplementation while seven received total parenteral nutrition (TPN). Sixteen of 21 patients who received INC had a decreased intake (x 48 +/- 24%) Recommended Dietary Allowances (RDA) for kilocalories and dramatic weight loss (x 16.4 +/- 12.4%). A total of 18 patients received TPN for a mean of 24 days (7-60); kcal averaged 90 +/- 26% RDA during weight gain. At onset of TPN, the mean serum albumin, transferrin and total lymphocyte counts were 3.06 +/- 0.38 g/dl, 175 +/- 62 mg/dl, and 1102 +/- 966/mm3 respectively, 15/18 children had subnormal anthropometric measurements and 17/18 patients were anergic to recall skin test antigens. TPN for less than 9-14 days neither repleted weight, skinfold reserves, nor serum albumin concentrations (greater than 3.2 g/dl) although an early increase (p less than .02) in transferrin concentration was observed. However, TPN for 28 days supported weight gain (3.27 kg, 16 +/- 6%), increased serum albumin (0.62 +/- 0.43 g/dl, p less than .001) and transferrin (62 +/- 42, p less than .002) to normal concentrations and reversed anergy in 7/11 patients retested. This study documents the severity of protein energy malnutrition which accompanies intense treatment of children with cancer and the nutritional and immunological benefits of a 28 day course of TPN.

Adolescent↗
PubMed1979

Impaired microtubule assembly and polymorphonuclear leucocyte function in the Chediak-Higashi syndrome correctable by ascorbic acid.

It was previously shown that the abnormal surface characteristics and defective bactericidal function of polymorphonuclear leucocytes (PMN) in the Chediak-Higashi syndrome (CHS) are correlated with impaired microtubule assembly, and in one patient direct electron microscopic evidence for an anomaly in microtubule assembly following surface membrane activation by concanavalin A (Con A). We show that very few microtubules are visible in CHS leucocytes from two additional patients under conditions where normal PMNs contain abundant microtubules, and that both in vivo and in vitro exposure of the CHS leucocytes to ascorbic acid promotes the assembly of microtubules. This agent, which normalizes chemotaxis and degranulation in CHS leucocytes, is shown also to correct granulocyte adherence in these leucocytes. It is suggested that the improved clinical course of patients with CHS following treatment with ascorbic acid is related at least in part to improvement of microtubule assembly and PMN function by the ascorbic acid.

Ascorbic Acid↗
PubMed1979

Hemoglobin Indianapolis (beta 112[G14] arginine). An unstable beta-chain variant producing the phenotype of severe beta-thalassemia.

Hemoglobin (Hb) Indianapolis is an extremely labile beta-chain variant, present in such small amounts that it was undetectable by usual techniques. Clinically, it produces the phenotype of severe beta-thalassemia. Biosynthetic studies showed a beta:alpha ratio of 0.5 in reticulocytes and about 1.0 in marrow after a 1-h incubation. These results, similar to those seen in typical heterozygous beta-thalassemia, suggested that betaIndianapolis was destroyed so rapidly that its net synthesis was essentially zero. To examine the kinetics of globin synthesis, reticulocyte incubations of 1.25--20 min were performed with [3H]leucine. The betaIndianapolis:beta A ratio at 1.25 min was 0.80 suggesting that beta Indianapolis was synthesized at a near normal rate. At 20 min, this ratio was 0.46 reflecting rapid turnover of beta Indianapolis. The erythrocyte ghosts from these incubations contained only betaIndianapolis and alpha-chains, and the proportion of betaIndianapolis decreased with time, indicating loss of betaIndianapolis. Pulse-chase studies showed little change in beta A:alpha ratio and decreasing betaIndianapolis:alpha and betaIndianapolis:beta A with time. The half-life of betaIndianapolis in the soluble hemoglobin was approximately equal to 7 min. There was also rapid loss of beta Indianapolis from the erythrocyte membrane. From these results, it may be inferred that betaIndianapolis is rapidly precipitated from the soluble cell phase to the membrane, where it is catabolized. Heterozygotes for beta 0-thalassemia usually have minimal hematologic abnormalities, whereas heterozygotes with betaIndianapolis, having a similar net content of beta-chain, have severe disease. The extremely rapid precipitation and catabolism of betaIndianapolis and the resulting excess of alpha-chains, both causing membrane damage, may be responsible for the severe clinical manifestations associated with this variant. It seems likely that other, similar disturbances in the primary sequence of globin polypeptide chains may produce clinical findings similar to those seen with hemoglobin Indianapolis and thus produce the phenotype of severe beta-thalassemia.

Adolescent↗
PubMed1979

Membrane fluidity in human and mouse Chediak-Higashi leukocytes.

Polymorphonuclear leukocytes from humans and mice with the Chediak-Higashi syndrome were characterized by spin label electron spin resonance spectrometry. Our results suggest that cells from afflicted mice and humans have membranes more fluid than controls. Order parameters for a spin label that probes near the membrane surface were 0.652 for normals and 0.645 for two Chediak-Higashi patients. Cells from Chediak-Higashi mice showed similar differences, as did isolated plasma membrane fractions. An increased membrane fluidity was also detected with a spin label that probes deeper in the bilayer. In vitro treatment of Chediak-Higashi mouse cells with 0.01 M ascorbate increased the order parameter to normal levels. In vitro incubation of mouse Chediak-Higashi cells with glucose oxidase increased the order parameter, similar to the effect of ascorbate. This increase was abolished when catalase was added to the incubation medium. In vitro incubation with dibutyryl cyclic guanosine monophosphate (1 muM to 0.1 mM) did not normalize order parameters. These results indicate that fluidity of Chediak-Higashi cell membranes was affected by treatments expected to alter the oxidation: reduction potential of the environment but was not affected by treatments expected to alter the ratio of intracellular cyclic nucleotides. The latter treatment would affect microtubule assembly. Therefore, it appears that the membrane fluidity abnormalities as demonstrated by electron spin resonance and the earlier demonstrated microtubule dysfunctions characteristic of Chediak-Higashi cells are coexisting defects and are probably not directly related.

Animals↗
PubMed1979

Utilization of liposomes for correction of the metabolic and bactericidal deficiencies in chronic granulomatous disease.

IgG-coated liposomes containing glucose oxidase (GO) in order to provide a means of generating H2O2 were prepared. Leukocytes from patients with chronic granulomatous disease (CGD) which are lacking a means of generating H2O2, ingested the IgG-coated liposomes and metabolic oxidative deficiencies of glucose-1-14C oxidation and iodination were normalized. Both of these activities have been shown to depend upon the availability of H2O2 within polymorphonuclear leukocytes. Improvement in the capacity to kill Staphylococcus aureus by chronic granulomatous disease leukocytes were observed under similar conditions. Thus, it is possible to restore the oxidative metabolic capacities to CGD leukocytes by the introduction of glucose oxidase containing liposomes to these cells.

Adult↗
PubMed1979

Effects of a chemotactic factor, N-formylmethionyl peptide, on adherence, superoxide anion generation, phagocytosis, and microtubule assembly of human polymorphonuclear leukocytes.

FMLP promoted microtubule assembly in PMNs at concentrations which were chemotactic for the cells. At higher concentrations than those required for chemotaxis, FMLP enhanced the adherence of PMNs to nylon glass fibers. With colchicine, PMN adherence was inhibited, but upon exposure to FMLP, PMN adherence could be restored. The effect of FMLP on PMN adherence was transitory and was no longer evident by 5 min. At concentrations similar to those employed in the adherence studies. FMLP induced the cells to briefly generate O-2, since ferricytochrome C reduction was no longer evident by 5 min. Pretreatment of the PMNs with cytochalasin B enhanced the release of O-2 by PMNs exposed to FMLP. On the other hand, there was no effect of FMLP on phagocytosis of C3-coated particles. These results suggest that FMLP induces responsive cells to develop a hyperadherent plasma membrane which is largely independent on microtubule control. Since oligopeptides similar of AMLP are formed in bacteria, it is likely that the action of N-formylated peptides is important in regulating the inflammatory response.

Cell Adhesion↗
PubMed1979

Evaluation of bone-marrow scanning with technetium-99m sulfur colloid in pediatric oncology.

Eighty-six technetium-99m sulfur colloid (Tc-SC) bone-marrow scans in 56 pediatric oncology patients were reviewed. The distribution of the sulfur colloid was similar to that in adult bone marrow in normal children older than 10 yr, and involved progressively more marrow of the extremities in normal children under 10 years of age. After irradiation or chemotherapy there was an extension of the Tc-SC to peripheral marrow sites. There was also diminished uptake of the tracer in sites corresponding to irradiated areas. In most patients there was recovery of these defects by 6 mo after completion of therapy. Tumor replacement of the marrow was reflected in the scans, and the extent of the scan defect paralleled the course of the disease. In four patients, despite normal bone scans and radiographs, marrow-scan abnormalities due to tumor replacement were present and confirmed by needle aspiration and/or biopsy. In two other patients, the marrow-scan abnormality preceded radiographic and histologic evidence of tumor metastasis. Two patients who responded clinically showed persistent defects; biopsy in one revealed fibrosis. Technetium-99m sulfur colloid bone-marrow scanning appears to be a sensitive monitor of marrow alteration caused by metastases, irradiation damage, or tissue fibrosis in children receiving treatment for cancer.

Adolescent↗
PubMed1979

Correlation of the FAB morphologic criteria and prognosis in acute lymphocytic leukemia of childhood.

The bone marrows at the time of initial diagnosis of 101 children with acute lymphocytic leukemia diagnosed from April 1969 to December 1974 were evaluated employing the FAB morphologic classification. The group with L1 morphology and a significantly improved duration of first remission and survival when compared to the L2--L3 morphologic groups. Both groups were similar in age and initial level of WBC, indicating that the morphologic classification has prognostic significance in childhood ALL when age and initial WBC were considered together as prognostic risk factors. The L1 morphologic groups survival for the low- and moderate-risk groups was significantly better than for the L1 high-risk group and for the L2--L3 groups.

Adolescent↗