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Biomedical subjects

M Link

Publications and source records attributed to M Link.

At least 19 recordsLinked to original sources
PubMed1992

A study of toxicity and comparative therapeutic efficacy of vindesine-prednisone vs. vincristine-prednisone in children with acute lymphoblastic leukemia in relapse. A Pediatric Oncology Group study.

Vindesine (des-acetyl Vinblastine) is a synthetic derivative of vinblastine, and was produced with the hope that it would have less neurotoxicity and hematopoietic toxicity than other vinca alkaloids. Phase I and II studies also demonstrated significant activity in lymphoid malignancies, especially Acute Lymphoblastic Leukemia (ALL). The present study was designed to compare therapeutic effectiveness of twice weekly vindesine (2 mg/M2/dose) plus Prednisone (60 mg/M2/dose) (Treatment 1) to weekly Vincristine (2 mg/M2/dose) plus Prednisone (60 mg/M2/day) (Treatment 2). All patients were less than 21 years of age, and had documented bone marrow relapse (blast count > 25%). In 39 patients presumed sensitive to vincristine, there were 11 complete responses out of 20 patients (55%) randomized to receive vindesine/prednisone and 7 complete responses out of 19 patients (37%) treated with Vincristine/Prednisone. In 37 patients resistant to vincristine, there were 7 complete responses (19%). Vindesine was more toxic than Vincristine. Major toxicities of vindesine included paraesthesias, peripheral neuropathy and ileus. Vindesine hematological toxicity appeared greater, but such toxicity is hard to assess in patients with bone marrow disease. In this study, vindesine and vincristine had similar efficacy, but vindesine use was associated with more toxicity.

Adolescent↗
PubMed1992

Keratin expression in cervical cancer.

Using a panel of 21 monoclonal and 2 polyclonal keratin antibodies, capable of detecting separately 11 subtypes of their epithelial intermediate filament proteins at the single cell level, we investigated keratin expression in 16 squamous cell carcinomas, 9 adenocarcinomas, and 3 adenosquamous carcinomas of the human uterine cervix. The keratin phenotype of the keratinizing squamous cell carcinoma was found to be most complex comprising keratins 4, 5, 6, 8, 13, 14, 16, 17, 18, 19, and usually keratin 10. The nonkeratinizing variety of the squamous cell carcinoma expressed keratins 6, 14, 17, and 19 in all cases, usually 4, 5, 7, 8, and 18, and sometimes keratins 10, 13, and 16. Adenocarcinomas displayed a less complex keratin expression pattern comprising keratins 7, 8, 17, 18, and 19, while keratin 14 was often present and keratins 4, 5, 10 and 13 were sporadically found in individual cells in a few cases. These keratin phenotypes may be useful in differential diagnostic considerations when distinguishing between keratinizing and nonkeratinizing carcinomas (using keratin 10, 13, and 16 antibodies), and also in the distinction between nonkeratinizing carcinomas and poorly differentiated adenocarcinomas, which do not express keratins 5 and 6. Keratin 17 may also be useful in distinguishing carcinomas of the cervix from those of the colon and also from mesotheliomas. Furthermore the presence of keratin 17 in a CIN I, II, or III lesion may indicate progressive potential while its absence could be indicative of a regressive behavior. Because most carcinomas express keratins 8, 14, 17, 18, and 19, we propose that this expression pattern reflects the origin of cervical cancer from a common progenitor cell, i.e., the endocervical reserve cell that has been shown to express keratins 5, 8, 14, 17, 18, and 19.

Adenocarcinoma↗
PubMed1992

Morphologic, immunologic and cytogenetic studies in children with acute lymphoblastic leukemia at diagnosis and relapse: a Pediatric Oncology Group study.

The morphologic, immunologic and cytogenetic features of leukemic cells obtained at the time of first bone marrow relapse were compared with those obtained at initial diagnosis in 287 children with acute lymphoblastic leukemia (ALL) who were entered consecutively in a laboratory classification study of the Pediatric Oncology Group (POG). L1 to L2 shifts in French-American-British morphologic subtype were more common than the reverse (81/178 versus 15/61, p less than 0.001). A small but marginally significant number of cases acquired cytoplasmic granules at relapse, and 50 cases underwent a shift in periodic acid-Schiff reactivity that slightly favoured positive to negative. Shifts in immunophenotype were relatively rare, although shifts in cases with a pre-B phenotype to early pre-B ALL or vice versa occurred in about a third of pre-B cases. Loss of HLA-DR or the common ALL antigen occurred in 20 and 11% of cases, respectively. Of the 116 cases with analyzable karyotypes at diagnosis and relapse, 36 (31%) showed a change in karyotypes at relapse, usually from normal to pseudodiploid or hyperdiploid. Cytogenetic evidence for the emergence of a new clone after initial diagnosis was found in only one case. Analysis of the correlation of clinical and lymphoblast biologic features with event-free survival after an initial marrow relapse failed to demonstrate any prognostic significance for the changes identified in this study. T-cell immunophenotype proved to be the only factor significantly related to the outcome of retrieval therapy.

Antigens, Differentiation↗
PubMed1991

Nitrogen mustard, vincristine, procarbazine, and prednisone as adjuvant chemotherapy in the treatment of medulloblastoma. A Pediatric Oncology Group study.

In a randomized postoperative trial, adjuvant post-irradiation chemotherapy, consisting of nitrogen mustard, vincristine, procarbazine, and prednisone (MOPP), was tested versus radiation therapy alone for newly diagnosed medulloblastoma in patients between 1 and 21 years of age. Patients treated with irradiation plus MOPP had a statistically significant increase in overall survival rate at 5 years posttreatment compared to patients treated with radiation therapy alone (74% vs. 56%; p = 0.06, adjusted for race and gender). Although the overall study failed to show a statistically significant advantage for irradiation plus MOPP in event-free survival (p = 0.18), statistical significance was attained in children 5 years of age or older (p = 0.05). More severe hematological toxicities occurred in the group with irradiation plus MOPP; however, this hematotoxicity appeared to be tolerable and acceptable. These results suggest that patients may benefit from combined irradiation and chemotherapy following surgery for medulloblastoma.

Adolescent↗
PubMed1991

Lack of transmission of the live attenuated varicella vaccine virus to immunocompromised children after immunization of their siblings.

The safety of administering the live attenuated Oka/Merck varicella vaccine to the well siblings of children with malignancy was evaluated as a strategy for reducing the risk of household exposure to varicella among immunocompromised children. Susceptible well children were eligible for vaccination if the child with malignancy had leukemia, lymphoma, or solid tumor in remission for 3 months or longer. No evidence of vaccine virus transmission was found among 30 children with malignancy whose 37 healthy susceptible siblings were immunized with varicella vaccine. Varicella-zoster virus was not isolated from the oropharyngeal secretions taken from 17 vaccinees or their 14 immunocompromised siblings. None of the 30 immunocompromised children had vaccine-related rashes or showed immunologic evidence of subclinical varicella-zoster virus infection based on testing for varicella-zoster virus IgG antibodies and T-lymphocyte proliferation to varicella-zoster virus. Four healthy vaccinees eventually had mild breakthrough cases of varicella, with transmission to the high-risk sibling in 3 cases. However, even in these families, the immunocompromised children had been protected from household exposure varicella for at least 20 months early in the course of their immunosuppressive treatment.

Adolescent↗
PubMed1990

Down-regulated c-myb expression inhibits DNA synthesis of T-leukemia cells in most patients.

We have investigated the functional relevance of c-myb expression for DNA synthesis in patients' T-leukemia cells. [3H]Thymidine incorporation assays of 32 patients' leukemia cells exposed in vitro to c-myb sense or antisense oligodeoxynucleotides served to define two groups of patients: a responder group whose leukemia cells showed 2- to 16-fold lower levels of [3H]thymidine incorporation in c-myb antisense-treated cultures than in c-myb sense-treated cultures (20 patients) and a nonresponder group whose cells showed comparable [3H]thymidine incorporation levels in either c-myb sense- or antisense-treated cultures (12 patients). Down-regulation of c-myb mRNA levels in cells exposed to c-myb antisense oligodeoxynucleotides was comparable in both groups of patients, indicating that differential sensitivity to c-myb antisense oligodeoxynucleotides was not due to differential uptake of these oligodeoxynucleotides. DNA polymerase alpha mRNA levels were down-regulated in cells from the responders but were unaffected in the nonresponder group. These results suggest that c-myb is required for DNA synthesis in cells of many but not all T-leukemia patients and that leukemia cells in which DNA synthesis is not inhibited despite down-regulation of c-myb expression may have undergone some genetic change(s) that obviate(s) the requirement for myb protein.

Base Sequence↗
PubMed1990

Philadelphia chromosome positive childhood acute lymphoblastic leukemia: clinical and cytogenetic characteristics and treatment outcome. A Pediatric Oncology Group study.

Among 3,638 children with acute lymphoblastic leukemia (ALL) entered on Pediatric Oncology Group (POG) protocols between June 1981 and April 1989, successful cytogenetic studies were available for 2,519, 58 (2.3%) of which had the Philadelphia (Ph) chromosome detected. Features associated with the presence of the Ph chromosome were high leukocyte count (median, 33 x 10(9)/L), older age median, 9.6 years), a higher proportion of French-American-British L2 morphology, and a lower frequency of mediastinal mass. Immunologic marker studies at diagnosis in 56 Ph+ cases identified early pre-B ALL in 42 cases (75%), pre-B-cell in 9 (16%), and T-cell in 5 (9%). This distribution is similar to that found in Ph+ ALL. Intensive multiagent chemotherapy induced complete remissions in only 78% of eligible Ph+ patients compared with 96% of those without an identified Ph chromosome (P less than .001). Of 44 eligible Ph+ patients treated on POG frontline protocols for children with non-T, non-B-cell ALL, 27 have failed therapy, compared with 520 of 1,892 without an identified Ph chromosome (logrank P less than .001). Ph+ ALL is an aggressive form of acute leukemia that frequently presents in older children with a high leukocyte count, FAB L2 morphology, and a pseudodiploid karyotype, and becomes multidrug-resistant early. Thus, Ph+ cases require early identification to permit treatment with intensive induction regimens and experimental approaches such as bone marrow transplantation.

Asparaginase↗
PubMed1989

Small cell osteosarcoma. A clinicopathologic study of 27 cases.

We report a study of 27 patients with small cell osteosarcoma (SCO), 17 from the M. D. Anderson Cancer Center (MDAH) and ten from the Pediatric Oncology Group (POG). There were 12 male patients and 15 female patients; 19 were white, five were black, and three were Hispanic. They ranged from 6 to 28 years of age with a median of 14 years. Histologically there were three patterns: Ewing's-like, lymphoma-like, and spindle cell. All cases showed osteoid formation and a few had chondroid areas. There was cytoplasmic glycogen in ten cases. Initial treatment for MDAH patients included intraarterial infusion of cisplatin in ten, amputation in four, partial mandibulectomies in two, and biopsy with local radiotherapy and systemic chemotherapy in one. All POG patients had resection or amputation followed by adjuvant chemotherapy. Twelve patients are alive, of whom nine have had significant follow-ups for 25 to 90 months. Fourteen patients are dead of lung, spine, and brain metastases from 1 to 23 months after initial diagnosis. One patient is alive with lung relapse at 4 months. In summary, SCO is a high-grade variant of osteosarcoma, with an incidence of up to 4% of all osteosarcomas, that affects patients of the same age group and has the same anatomic location as conventional osteosarcoma. Currently, SCO appears to have a prognosis that is the same as or slightly worse than that of conventional osteosarcoma. Furthermore, although intraarterial infusion is effective for the primary tumors in the bone, distant metastases are difficult to control.

Adolescent↗
PubMed1989

[The validity of parameters in neonatal diagnosis and fetal monitoring of breech deliveries. 1. Neonatal status after breech delivery].

By means of 522 singles in breech presentation the pH of umbilical artery (pH u. a.) and Apgar score in comparison to the mode of delivery, duration of pregnancy and weight of neonates have been analysed. The frequency of deliveries by cesarean section in breech presentation was 28.3%, the rate of preterms in these cases amounts to 14.6% and the perinatal mortality to 42.1%. The average value of pH u.a. after vaginal delivery (7.25) was significantly different to the value after cesarean section (7.28). 25% of the pH-values were below 7.20, 10% below 7.10. Mixed acidoses dominated, metabolic ones after vaginal and abdominal deliveries equalled each other. Vaginal deliveries were frequently followed by respiratory acidoses. In 81% of one-minute-Apgar and in 93% of five-minute-Apgar, the score was above 7. According to our experiences the only determination of the pH u.a. after breech deliveries is not sufficient, because of being at risk for the fetus it demands the measurement of the complete acid-base-status. A critical comparison of these data with the clinical status of the newborn is necessary.

Acidosis↗
PubMed1989

[The validity of parameters in neonatal diagnosis and fetal monitoring of breech deliveries. 2. Problems in fetal monitoring in the breech position--a proposal for a standardized biochemical diagnosis].

By means of 149 fetal microblood samplings (FBA) from the breech in deliveries in breech presentation and by means of 64 cardiotocograms the validity of biochemical parameters and biophysical ones of fetal monitoring will be investigated. It takes an increased number of suspect or pathologic CTG into account in cases of breech presentation. By means of FBA it is possible to exclude or to confirm the supposed acidoses. By this the rate of operations during delivery can be reduced or the operation will be indicated respectively. A normal fetal pH resulting from the general biochemical monitoring does enlarge the obstetricians license when the fetus presents himself in advanced parturition in pelvic floor (hold back of breech during assisted spontaneous delivery). A pH less than 7.15 demands an immediate delivery. A prognosis of fetal outcome by means of FBA and CTG is not possible due to difficulties in calculation of the final stage of breech presentation. The difference between fetal pH measured in pelvic floor and pH in umbilical artery must be kept as small as possible and it might be regarded as criterion of the management of the delivery in breech presentation.

Acidosis↗
PubMed1989

[The frequency of Chlamydia detection in gynecologic and obstetrical patients and newborns].

Chlamydia trachomatis is said to play an important role in the pathogenesis of gynecologic, perinatal and neonatal infectious morbidity. Chlamydia trachomatis is responsible for several infectious syndromes in non-pregnant women, mothers and their offspring. We investigated the incidence of Chlamydia trachomatis in 353 non-pregnant and pregnant women without complaints and in 50 newborn. Chlamydia trachomatis was isolated from 6% of genital carcinoma, about 20% of different gynecological diseases and pregnant women within the first and third trimenon, 35% of puerperas and 10% of newborns. The prevalence of Chlamydia trachomatis antibody occurred in 34 to 55% of the non-pregnant and pregnant women and in 38% of the newborns. We propose a screening for Chlamydia trachomatis infection in high-risk patients and in pregnancy and a treatment of infected individuals.

Antibodies, Bacterial↗
PubMed1989

Long-term growth of malignant thymocytes in vitro.

We report a new methodology for the long-term growth of malignant T-lymphoblasts from patients with T-cell acute lymphoblastic leukemia (T-ALL) and T-cell lymphoblastic lymphoma (T-LL). When malignant cells were cultured in the presence of insulin-like growth factor I under hypoxic conditions, cellular proliferation occurred that resulted in the establishment of immortal cell lines from ten of 12 patient tumors. Authenticity of each cell line was verified by a direct comparison of the immunophenotype, karyotype, and immunogenotype with the patient's tumor cells. This improved method of cell culture permits frequent establishment of cell lines from patients with T-ALL/T-LL, thereby aiding in analysis of thymocyte transformation and neoplasia.

Adolescent↗
PubMed1988

Continuing rearrangement but absence of somatic hypermutation in immunoglobulin genes of human B cell precursor leukemia.

Southern blot analyses revealed that cells from nearly 30% of childhood B cell precursor acute lymphoblastic leukemias (ALLs) contained more than two rearranged, nongermline bands for Ig heavy chain genes. DNA corresponding to these bands was molecularly cloned from two cases which showed three and seven rearranged bands, respectively. Nucleotide sequence analysis of the cloned DNA demonstrated that each band represented different VDJ or DJ rearrangements. While the same DJ joints were shared by several rearrangements, different DJ joints were found in the majority of rearrangements, precluding V region substitution as an explanation for the multiplicity of heavy chain rearrangements in these leukemias. Most of the V region segments involved in these rearrangements were restricted to VH region families that have been shown previously to be preferentially rearranged in human fetal B lineage cells. Sequence analysis of multiple copies of the same VDJ rearrangements from different cells revealed no somatic mutation, a mechanism responsible for detection of extra rearranged Ig DNA bands in certain other B lineage tumors. The data suggest that in some cases of ALL Ig heavy chain genes begin and continue to rearrange de novo within the neoplastic B cell precursor populations derived from an original malignant cell transformed at a stem cell stage of differentiation.

Amino Acid Sequence↗
PubMed1988

Cellular immune reactions and blood cerebrospinal fluid barrier dysfunction in guinea pigs.

Both young and adult strain 13 guinea pigs have been treated with complete Freund's adjuvant (CFA). In young animals CFA induced an increase in the lymphocyte cell count in blood and a reversible blood CSF barrier impairment. Both these effects could be suppressed by the immunosuppressant drug Cyclosporin A. In contrast to the young animals treatment with CFA in adult strain 13 guinea pigs influenced neither the lymphocyte cell count nor blood CSF barrier function. In young and adult CFA-treated animals the number of polymorphonuclear cells in blood were increased and this increase was not reversed by Cyclosporin A. We discuss the influence of a systemic immune stimulation and suppression on blood CSF barrier function for proteins and its relevance to the pathogenesis of inflammatory diseases of the central nervous system.

Animals↗