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Biomedical subjects

R Wesley

Publications and source records attributed to R Wesley.

At least 37 records · Page 2Linked to original sources

The amino-terminal signal peptide on the porcine transmissible gastroenteritis coronavirus matrix protein is not an absolute requirement for membrane translocation and glycosylation.

cDNA clones mapping within the first 2601 bases of the 3' end of the porcine transmissible gastroenteritis corona-virus (TGEV) genome were sequenced by the method of Maxam and Gilbert and an open reading frame yielding a protein having properties of the matrix (M or E1) protein was identified. It is positioned at the 5' side of the nucleocapsid (N) gene from which it is separated by an intergenic stretch of 12 bases. The deduced M protein comprises 262 amino acids, has a molecular weight of 29,544, is moderately hydrophobic, and has a net charge of +7 at neutral pH. Thirty-four percent of its amino acid sequence is homologous with the M protein of the bovine coronavirus (BCV), 32% with that of the mouse hepatitis coronavirus (MHV), and 19% with that of the avian infectious bronchitis coronavirus (IBV). Judging from alignment with the BCV, MHV, and IBV M proteins, the amino terminus of the TGEV M protein extends 54 amino acids from the virion envelope which compares with only 28 for BCV, 26 for MHV, and 21 for IBV. Eleven of the sixteen amino-terminal amino acids are hydrophobic and the positions of charged amino acids around this sequence suggest that the first 16 amino acids comprise a potentially cleavable signal peptide for membrane insertion. A similar sequence is not found in the M proteins of BCV, MHV, or IBV. When mRNA from infected cells, or RNA prepared by in vitro transcription of the reconstructed M gene, was translated in vitro in the presence of microsomes, the M protein became translocated and glycosylated. When a protein without the amino-terminal signal peptide was made by translating a truncated version of the M gene transcript, some translocation and glycosylation also occurred suggesting that the amino-terminal signal peptide on the TGEV M protein is not an absolute requirement for membrane translocation. Interestingly, the amino-terminal peptide did not appear to be cleaved during in vitro translation in the presence of microsomes suggesting that a step in virion assembly may be required for proper exposure of the cleavage site to the signal peptidase.

Amino Acid Sequence

Preliminary results of treatment of Ewing's sarcoma of bone in children and young adults: six months of intensive combined modality therapy without maintenance.

Thirty-one previously untreated patients with Ewing's sarcoma were treated with an intensive chemotherapy program of vincristine, Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH), and cyclosphosphamide (VADRIAC) in combination with radiation therapy to the primary site (greater than 50 Gy) and bone metastases (45 to 50 Gy). An intensified regimen with one further cycle of chemotherapy (VADRIAC), total body irradiation (TBI), and autologous bone marrow transplantation was given to patients with primary tumors of the pelvis, humerus, femur, and chest wall without metastases and to all patients with metastases at diagnosis. Patients with primary tumors of the distal extremity and other sites without metastases at diagnosis were treated on a less intensive chemotherapy regimen of VADRIAC without the intensification. Therapy was completed within 6 to 7 months in all patients. Thirteen patients had metastatic disease at diagnosis; only two of these had the lung as the sole site of metastatic disease. Eighteen patients had no evidence of metastatic disease at diagnosis: ten of these patients had tumors that arose in central axis and proximal extremity sites, and eight had tumors that arose in distal extremity and other sites. Thirty of the 31 patients achieved a complete remission, although two patients underwent amputation: one before chemotherapy and radiation and one after chemotherapy and radiation because of persistent local disease. Seventeen remain in their first complete remission at a median time on study of 30 months and a median time after completion of therapy of 24 months. Fourteen patients have relapsed (13) or progressed (1): ten in metastatic sites and four in the primary site. One patient had persistent local disease after radiation requiring amputation. Nine of the 13 patients with metastatic disease at diagnosis have relapsed compared with five of the 18 patients without metastatic disease. For the entire group, the actuarial survival is 78% (65% to 87%) at 30 months, and the actuarial disease-free survival is 58% (46% to 69%) at 30 months.

Adolescent

Nucleotide sequence of the porcine transmissible gastroenteritis coronavirus matrix protein gene.

cDNA clones mapping within the first 2601 bases of the 3' end of the TGEV genome were sequenced completely or in part by the method of Maxam and Gilbert and open reading frames were examined. One reading frame yielding a protein having properties of the matrix (M) protein was identified. It is positioned at the immediate 5' side of the nucleocapsid (N) gene but is separated by an intergenic region of 12 bases. The deduced M protein is comprised of 262 amino acids, has a molecular weight of 29,544, is moderately hydrophobic, and has an amino acid sequence homology of approximately 36% with the mouse hepatitis coronavirus, 37% with the bovine enteric coronavirus, and 28% with the avian infectious bronchitis virus. Judging from an alignment with MHV and IBV proteins, the amino terminus of the TGEV M protein extends 54 amino acids from the virion envelope which compares with 26 for MHV and 21 for IBV.

Amino Acid Sequence

High-dose oral and intravenous metoclopramide in doxorubicin/cyclophosphamide-induced emesis. A randomized double-blind study.

Emesis remains a major side effect of cancer chemotherapy. High-dose intravenous metoclopramide has proved to be effective antiemetic therapy for cisplatinum induced emesis. It has not been rigorously tested in nonplatinum chemotherapy. This double-blind, noncrossover, randomized trial compared high-dose oral and intravenous metoclopramide to standard oral prochlorperazine in emesis caused by doxorubicin [70 mg/m2 body surface area (BSA)] and cyclophosphamide (700 mg/m2 BSA). Prochlorperazine (10 mg/dose), oral metoclopramide, and intravenous metoclopramide (2 mg/kg/dose each) were given 30 min before chemotherapy and then every 4 h for 24 h. Ten patients were randomized to prochlorperazine therapy, 10 to oral metoclopramide, and 9 to i.v. metoclopramide. Median number of emeses for the first chemotherapy cycle was 3, 3, and 7 for prochlorperazine, oral, and i.v. metoclopramide, respectively. Statistical analysis showed no significant advantage of any regimen (p greater than 0.4). For patients who continued the antiemetic study, frequency of emesis increased with each successive cycle of chemotherapy. Six of 19 patients treated with metoclopramide developed dystonic reactions compared with zero of 10 on prochlorperazine. High plasma metoclopramide levels were achieved with both metoclopramide regimens and did not correlate with frequency of emesis. High-dose oral and i.v. metoclopramide in an every 4 h regimen did not show any advantage over standard antiemetic therapy for doxorubicin/cyclophosphamide-induced emesis and were associated with significant toxicity.

Administration, Oral

Treatment of peripheral neuroepithelioma in children and young adults.

Seventeen patients with peripheral neuroepithelioma were treated with an intensive chemotherapy regimen of vincristine, Adriamycin (Adria Laboratories, Columbus, OH), and cyclophosphamide (VADRIAC) in combination with radiation therapy. Fifteen patients with stage III (seven) or stage IV (eight) at presentation were treated on a more intensive regimen including total body irradiation (TBI) (8 Gy). Two patients with stage I (one) or II (one) disease received a less intensive chemotherapy regimen of VADRIAC. Therapy was completed within 6 to 7 months in all patients. The disease arose in the chest wall in 12 patients, pelvis in three patients, and extremity in two patients. Sixteen of the 17 (94%) patients achieved a complete remission. With a median follow-up of 18 months, ten patients remain in complete remission with an actuarial survival of 68% and an actuarial relapse-free survival of 56% at 12 months. On the basis of our initial experience with this tumor, we believe that peripheral neuroepithelioma is a chemoresponsive and radioresponsive tumor.

Adolescent

Ifosfamide with mesna uroprotection and etoposide: an effective regimen in the treatment of recurrent sarcomas and other tumors of children and young adults.

One hundred twenty-four children and young adults with recurrent tumors, predominantly sarcomas, were treated with the combination of ifosfamide, etoposide, and the uroprotector, mesna (2-mercaptoethane sulphonate), in a phase II trial. The treatment regimen consisted of 12 cycles of therapy administered every 3 weeks. After evaluation of the tumor response to chemotherapy alone, radiation or surgery was used to eradicate residual sites of metastatic disease where possible. At the present time, 77 patients are evaluable for response to the chemotherapy; 43 of the patients have experienced a significant reduction in the tumor size in response to the chemotherapy alone (39 partial responses [PR] and four complete responses [CR]). Sixteen of 17 patients with Ewing's sarcoma, nine of 13 with rhabdomyosarcoma, four of eight with peripheral neuroepithelioma, three of eight with osteosarcoma, and 11 of 31 with other tumors have responded with a PR or CR. The toxicity of the regimen was acceptable. Moderate or severe toxicity evaluated on a per cycle basis included: neutropenia, 97%; thrombocytopenia, 32%; nephrotoxicity, less than 1%; mucositis, 1%; neurologic toxicity, 2%; nausea and vomiting, 13%; hemorrhagic cystitis, less than 1%. Fever was present after 33% of cycles and sepsis following 7%. One patient died due to sepsis and pancytopenia. At the present time, only seven of the 43 patients who responded to the chemotherapy regimen have relapsed, with a median follow-up of 10 weeks after the response. This drug combination is highly active in the treatment of recurrent sarcomas and other tumors in children and young adults.

Adolescent

Resident test ordering patterns.

Utilization of a selected set of laboratory tests in the ambulatory setting was determined for four classes of family practice residents over their entire three year training program. A total of nineteen residents were included in the study. Residents' test utilization in their third year of training was significantly lower than in their Post Graduate Year I (PGY I) and PGY II years. Though there was a substantial drop in residents' utilization between their first and second year, the drop was not significant. While most residents reduced their test utilization as they progressed through residency, several who were extremely low utilization in there first year of training actually increase test utilization in the second year. There was substantial variation in residents' test utilization, most marked in the first year but persisting for all three years. Although test utilization progressively fell through the three years of training, the residents who were high utilizers during their first year of training remained high utilizers for the remainder of their training. Though the variation in resident test utilization apparent in PGYI was maintained throughout residency, the degree of variation was reduced and greater uniformity was achieved as training progressed.

Clinical Laboratory Techniques

Adverse prognostic influence of hepatitis B virus infection in acute lymphoblastic leukemia.

Liver function test abnormalities were examined in a retrospective survey in a population of 90 children with acute lymphoblastic leukemia (ALL) treated in a similar fashion with therapy, using primarily methotrexate, mercaptopurine, vincristine, and prednisone. A twofold or greater elevation of serum glutamyl pyruvic transaminase (SGPT) was found in 80% of the patients during induction therapy, in 63% of the patients during maintenance therapy, and 31% of the patients who completed therapy. Circulating hepatitis B virus surface antigen (HBsAg) was noted in 26% of patients with liver function test abnormalities during maintenance therapy, and 45% of patients with liver function test abnormalities after the completion of therapy. Hepatitis B virus infection was therefore, the most important single cause of abnormal liver function during remission in our patient population. Though others have asserted that hepatitis B virus infection is relatively benign in immunosuppressed individuals, in our population, this agent often caused severe pathological and clinical sequelae. This may be related to the high frequency (50%) of co-infection with the delta agent in our HBsAg-positive patients. Furthermore, hepatitis B virus surface antigenemia conferred an adverse prognostic influence for these children in terms of their leukemia-free survival.

Acute Disease

5-Fluorouracil chemotherapy and pelvic radiation in the treatment of large bowel cancer. Decreased toxicity in combined treatment with 5-fluorouracil administration through the intraperitoneal route.

Multimodality cancer therapy commonly involves the interactions of surgeon, radiation therapist, and medical oncologist. This prospective study was undertaken to record possible adverse effects of surgery, external beam radiation therapy, and 5-fluorouracil (5-FU) chemotherapy in the treatment of large bowel cancer. The dose of 5-FU by the intraperitoneal (IP) or intravenous (IV) routes was diminished when pelvic radiation therapy was given. The reduction in drug dose that was required was much greater when 5-FU was given IV as compared to IP. The proportion of patients remaining on IV 5-FU chemotherapy was significantly reduced when the patient received pelvic radiation. There was a significant increase in leukopenia and thrombocytopenia when patients received pelvic radiation. Hematologic toxicity was more severe when there was IV compared with IP administration of 5-FU. Pelvic radiation therapy diminished the patient's capacity to receive chemotherapy because of hematologic toxicity. The locoregional administration of 5-FU chemotherapy was better tolerated as part of a multimodality treatment regimen than was systemic administration.

Clinical Trials as Topic

High-grade soft tissue sarcomas of the extremities.

From July 1975 to December 1982, 358 patients were referred to the Surgery Branch of the National Cancer Institute (NCI) with the diagnosis of soft tissue sarcoma of the extremities. Two hundred eleven of these patients presented with resectable, localized high-grade soft-tissue sarcomas and have been included in the present analysis of the management and outcome of patients with high-grade soft tissue sarcomas of the extremity treated at the NCI. One hundred forty-seven of these 211 patients have been included in randomized prospective trials. The remaining 64 patients in this analysis have been followed at the NCI, but were not included in randomized trials because of patient refusal or ineligibility. Tumor size was identified as a highly significant prognostic variable for disease-free and overall survival (P2 = 0.00001 and 0.0081, respectively). Tumor site, histologic type, and microscopic margins of resection were not significant prognostic variables. There was no difference between patients undergoing amputation compared to those undergoing limb-sparing procedures plus postoperative radiotherapy in disease-free or overall survival for all 211 patients in this study (P2 = 0.068 and 0.131, respectively). A significantly greater frequency of local failure among patients treated by local excision was noted compared to patients undergoing amputation (12/128 versus 0/83, P2 = 0.004), but this did not result in decreased overall survival in patients undergoing combined modality limb-sparing procedures. Adjuvant chemotherapy significantly prolonged disease-free survival (P2 = 0.005) for the 124/211 patients treated with adjuvant chemotherapy, although analysis of overall survival did not reveal a significant increase (P2 = 0.10). In a subset of 65 patients included in a prospective randomized trial evaluating the efficacy of adjuvant chemotherapy, a significant improvement in both disease-free (P2 = 0.033) and overall (P2 = 0.055) survival was seen in patients receiving chemotherapy. Sixty-five patients developed recurrent disease (65/211, 31%) and 42 of these patients were rendered disease-free surgically. Survival from the time of first recurrence was significantly prolonged among the 42 patients who were rendered disease-free (median survival, 31 months) compared to those who were not (median survival, 9 months, P2 less than 0.001).

Actuarial Analysis

Excess prevalence of Pneumocystis carinii pneumonia in patients treated for lymphoma with combination chemotherapy.

A significantly greater prevalence of interstitial pulmonary infiltrates and Pneumocystis carinii pneumonitis occurred on one arm of a randomized study comparing ProMACE-CytaBOM (prednisone, methotrexate with leucovorin, doxorubicin, cyclophosphamide, etoposide; cytarabine, bleomycin, vincristine, methotrexate with leucovorin) to ProMACE-MOPP (ProMACE, mechlorethamine, vincristine, prednisone, procarbazine) chemotherapy in patients with lymphoma. Of the 37 patients receiving ProMACE-CytaBOM, 13 (35.1%) developed an interstitial pulmonary infiltrate compared with 3 of 32 (9.4%) patients receiving ProMACE-MOPP (p2 = 0.02). Of the 13 patients receiving ProMACE-CytaBOM who had infiltrates, open lung biopsy in 7 showed P. carinii; 5 others had clinically suspected P. carinii pneumonia, and 1 had blastomycosis. No patient receiving ProMACE-MOPP had documented or suspected P. carinii pneumonia. Of patients with infiltrates, 3 of 13 on ProMACE-CytaBOM but 0 of 3 on ProMACE-MOPP died. Two other patients on ProMACE-CytaBOM who had P. carinii pneumonia died. Groups did not differ in predisposing risk factors or patient history. The exact cause for the increased prevalence of P. carinii infection in patients receiving ProMACE-CytaBOM was not ascertained. These data emphasize that new drug regimens may lead to unanticipated complications.

Adult

Prospective randomized study of open lung biopsy versus empirical antibiotic therapy for acute pneumonitis in nonneutropenic cancer patients.

Diffuse pulmonary infiltrates and acute respiratory compromise frequently occur in patients with cancer who are undergoing chemotherapy, and treatment remains controversial. We initiated a prospective randomized trial in 22 nonneutropenic patients to compare the efficacy of immediate open lung biopsy with that of empirical trimethoprim-sulfamethoxazole and erythromycin therapy with delayed open lung biopsy if no clinical improvement occurred after 4 days of therapy. Diagnoses included non-Hodgkin's lymphoma (15 patients), T-cell lymphoma (2), acute lymphoblastic leukemia (3), Hodgkin's disease (1), and breast cancer (1). The median age was 40 years, and fever (18) and tachypnea (13) were the most frequent signs. Median room air arterial oxygen tension in 18 hypoxic patients was 53 mm Hg; 19 patients had diffuse pulmonary infiltrates. Eight of the 10 patients randomized to empirical antibiotic therapy showed improvement after 4 days. The 2 patients whose condition did not improve and who underwent delayed open lung biopsy had Pneumocystis carinii pneumonia. One of them did show improvement, and the other died of respiratory failure. Time to clinical resolution in the 9 surviving patients was 14 days; 4 required prolonged ventilation (longer than 24 hours). Findings for the 12 patients randomized to immediate open lung biopsy were P. carinii pneumonia in 7 and nonspecific pneumonitis in 5; there were 3 deaths related to open lung biopsy. Time to resolution in the surviving patients was 13 days for those with P. carinii pneumonia and 5 days for those with nonspecific pneumonitis; 7 required prolonged ventilation.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease

Patterns of recurrence in patients with high-grade soft-tissue sarcomas.

From July 1975 to December 1982, 563 patients were referred to the Surgery Branch of the National Cancer Institute with the diagnosis of soft-tissue sarcoma. Three hundred and seven of these patients had fully resectable, localized high-grade soft-tissue sarcomas and were treated at the National Cancer Institute using standard protocols with surgery alone, or in combination with chemotherapy and/or radiotherapy. An aggressive surgical approach was undertaken in the management of patients who subsequently developed recurrent disease. These 307 cases have been reviewed, with a median duration of follow-up of 30 months, to determine the frequency of recurrent disease, the patterns of recurrence, and the impact of surgery on the survival of patients who developed recurrent disease. Disease recurred in one hundred seven patients (107/307, 35%), with a median disease-free interval of 18 months (range, 0.5 to 72.0 months). The frequency of recurrence by site of primary sarcoma was extremity, 31% (65/211); head and neck, 33% (4/12); trunk, 40% (17/42); retroperitoneum, 47% (17/36); and breast, 67% (4/6). Isolated pulmonary metastatic disease was the most common pattern of initial recurrence (56/107, 52%) followed by isolated local recurrence (21/107, 20%). Single other sites of recurrence and multiple concurrent sites of recurrence each accounted for 14% (15/107) of all initial recurrences. The relative frequency of each of these four patterns of recurrence varied with the site of the primary sarcoma. The outcome for patients with recurrent disease depended on the site of recurrence, rather than on the site of the primary sarcoma. Sixty-six patients (66/107, 62%) with recurrent disease were rendered surgically disease-free with the first recurrence, including 40 (40/56, 72%) patients with isolated pulmonary metastases, 20 patients (20/21, 96%) with isolated local recurrences, five patients (5/15, 33%), with isolated other sites of recurrence and one patient (1/15, 7%) with multiple sites of initial recurrence. Following surgical resection, the actuarial three-year survival for the 66 patients rendered disease-free was 51%. The median survival for the 41 patients not rendered surgically disease-free with the first recurrence was only 7.4 months. Thirty of the sixty-six patients (30/66, 45%) rendered disease-free with the first recurrence remained disease-free at follow-up, with a median follow-up of 28 months from the time of resection of the first recurrence. The remaining 36 patients (36/66, 55%) subsequently recurred, with a median disease-free interval of 7.3 months.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent

Perioperative blood transfusions are associated with increased rates of recurrence and decreased survival in patients with high-grade soft-tissue sarcomas of the extremities.

One hundred fifty-six patients with high-grade soft-tissue sarcomas of the extremities treated on prospective randomized trials were analyzed to determine the impact of perioperative blood transfusions on tumor recurrence and patient survival. A significant increase in the incidence of tumor recurrence and decrease in survival were associated with the receipt of blood transfusions at the time of definitive surgical therapy of the sarcoma. Actuarial 5-year continuous disease-free survival was 70% in patients who had not been transfused compared to 48% in patients who received one or more transfusions (P = .007). Overall 5-year survival was also substantially decreased in patients receiving transfusions (85% compared to 63%; P = .0035). A direct relationship existed between the number of transfusions administered and the decrease in disease-free and overall survival; the larger the number of transfusions the worse the prognosis (P less than .0001 and P = .0001, respectively). A large number of other prognostic factors were included in the analysis including the age, sex, race of the patient, histology of the primary lesion, anatomic site of the primary lesion, final surgical margins, size of the tumor, type of surgery required, the use of chemotherapy, actual time in the operating room under anesthesia, the exact anesthetic agent used, and the individual surgeon who performed the operation. Accounting for all of these factors a strong association continued to exist between the receipt of blood transfusion and poor patient prognosis. We have previously shown that adjuvant chemotherapy is of benefit to patients with high-grade extremity sarcomas, and 132 (84.6%) of 156 patients in this series received chemotherapy. In patients receiving chemotherapy, blood transfusions were associated with increased recurrence (P less than .0001) and decreased survival (P = .0001). The only other significant independent prognostic variable in these patients was the size of the primary tumor. An analysis of all patients, stratified for tumor size, revealed an impact of transfusions on increasing recurrence (P = .007) and decreasing survival (P = .016). An analysis of the subpopulation of patients with large tumors (greater than 150 mL) gave the same results (P = .03 and .015, respectively). It thus appears that the receipt of blood transfusions is associated with increased tumor recurrence and decreased survival in patients with high-grade soft-tissue sarcomas of the extremities.(ABSTRACT TRUNCATED AT 400 WORDS)

Actuarial Analysis

Prospective, randomized trial of intravenous versus intraperitoneal 5-fluorouracil in patients with advanced primary colon or rectal cancer.

No new chemotherapy agents have been developed recently that present hope for improving survival in patients with colon or rectal cancer. We undertook this study to investigate a new route of administering an old drug, 5-fluorouracil (5-FU). Sixty-six patients with advanced primary colon or rectal cancer were randomized to receive 12 cycles with increasing dosages of intravenous (IV) or intraperitoneal (IP) 5-FU; the mean follow-up time was three years. The maximal tolerable dose and objective adverse side effects were prospectively recorded. The mean daily dose of 5-FU given by the IV route was 904 mg; for the IP route it was 1361 mg (p2 less than 0.0001). Two of ten patients had recurrent peritoneal carcinomatosis when treated with IP 5-FU; ten of eleven patients treated with IV 5-FU developed peritoneal implants (p2 less than 0.003). The incidence of serious complications was the same, but hematologic toxicity and hepatic toxicity were significantly reduced in patients who received IP 5-FU. When 5-FU is delivered by the IP route, the tolerable dose of drug was markedly increased without an increase in adverse side effects. The natural history of surgically treated disease was changed by reducing the incidence of peritoneal carcinomatosis but time to relapse and survival was not improved. IP 5-FU may be recommended for investigation in patients with perforated colon cancer, peritoneal implants, or as one part of a multimodality treatment protocol for colorectal cancer. If 5-FU is given to patients with gastrointestinal malignancy, the IP route should be strongly considered.

Adult

Prospective randomized trial of intravenous v intraperitoneal 5-FU in patients with advanced primary colon or rectal cancer.

No new chemotherapy agents have been developed in the recent past that present hope for improving survival in patients with colon or rectal cancer. This study was undertaken to investigate a new route of administering an old drug, 5-fluorouracil (5-FU). When 5-FU is delivered by the intraperitoneal (IP) route the tolerable dose of drug was markedly increased without an increase in adverse side effects. The natural history of surgically treated disease was changed by reducing the incidence of peritoneal carcinomatosis, but time to relapse and survival was not improved. Intraperitoneal 5-FU may be recommended for investigation in patients with perforated colon cancer, peritoneal implants, or as one part of a multimodality treatment protocol for colorectal cancer. If 5-FU is given to patients with gastrointestinal malignancy, the IP route should be strongly considered.

Adult