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Biomedical subjects

F Richards

Publications and source records attributed to F Richards.

At least 55 records · Page 3Linked to original sources
PubMed1991

Knowledge, attitudes and perceptions (KAP) of onchocerciasis: a survey among residents in an endemic area in Guatemala targeted for mass chemotherapy with ivermectin.

If ivermectin distribution programs are to have maximum impact on the morbidity and transmission of human onchocerciasis there must be broad and sustained acceptance within the endemic communities. Educational activities, developed with careful consideration of community attitudes, should promote positive treatment seeking behavior while simultaneously addressing local reservations about the control effort. To better understand the ambient knowledge, attitudes, and practices concerning onchocerciasis in the context of ivermectin use in Guatemala, we conducted a survey among 145 heads of households in five endemic communities. Given the country's long-standing nodulectomy program, it was not surprising that 100% of persons interviewed had heard of the disease 'la filaria', which they defined as a skin nodule that could cause blindness. Ninety-five percent of respondents identified surgery as the only cure for the condition. Relatively few (39%) knew that la filaria was caused by a worm, although slightly more (50%) knew that the condition was acquired by the bite of an insect. The term microfilaria was not broadly recognized. We also determined that onchocerciasis was not perceived as a serious health problem: few persons (12%) mentioned la filaria when requested to provide a complete list of illnesses that occurred in the community, and the gravity of infection (based on rank ordering of common illnesses) was similar to that of a bad cold. Recommendations were made which might assist long-term acceptance of a national chemotherapy initiative against onchocerciasis in Guatemala.

Adolescent↗
PubMed1991

The influence of drug interval on the effect of methotrexate and fluorouracil in the treatment of advanced colorectal cancer.

The importance of the interval between methotrexate (MTX) and fluorouracil (5-FU) was studied in 168 patients with previously untreated, measurable, advanced colorectal cancer. They were randomized to receive MTX 200 mg/m2, followed by 5-FU 600 mg/m2 either 24 hours (arm A) or 1 hour (arm B) after MTX. All patients received leucovorin (LV) 24 hours after MTX, 10 mg/m2 orally every 6 hours for six doses. The regimen was repeated every 2 weeks, with 5-FU escalation as tolerated. Arm A was significantly better than arm B with respect to overall response rate (29% v 14.5%, P = .026), time to progression (TTP; median, 9.9 months v 5.9 months, P = .009), and survival (median, 15.3 months v 11.4 months, P = .003). Significant differences between arms were not found in response rate, median TTP, or median survival for the subgroup of patients with rectal primaries who comprised 20% of the patients in each arm. Significant factors prognostic for survival were performance status and number of metastases, as well as treatment. Age did not influence survival. Toxicity was similar in both arms and was primarily gastrointestinal. More mucositis was seen in arm A. There were four toxic deaths secondary to neutropenia and infection (one from arm A and three from arm B) and three other deaths (two from arm A and one from arm B) that were possibly drug-related. The combination of MTX with LV rescue and 5-FU is an active regimen in advanced colorectal cancer; its efficacy is increased in colon, but not rectal cancer, when the interval between MTX and 5-FU is long (24 hours) rather than short (1 hour).

Aged↗
PubMed1991

Laboratory diagnosis of cysticercosis.

Human cysticercosis is caused by cystic tissue larvae of Taenia solium acquired by ingesting the eggs of the T. solium tapeworm. The diagnosis of human cysticercosis can be made by radiologic imaging, tissue biopsy, or serology. Radiologic imaging, including MRI and CT, currently is the most effective means for diagnosis.

Animals↗
PubMed1991

An urban primary school health program.

This paper summarizes the results of the first three years of an integrated on-site school health demonstration project based on the family practice model of delivering primary health care. An inner city public elementary school was chosen as the study location. Of the 712 study participants, 98% were black or Hispanic. Prior to implementation of the demonstration project, the Health Guarded Index for the study population was computed to be 58%. Among study participants, this index rose to 79% during the first year of the project and eventually reached 95% during the third year of the project. The absentee rates among study participants relative to nonparticipants decreased to 8.7% during the first year of the project and by 36.2% during the third year of the project. The substantial increase in the Health Guarded Index indicates that, among study participants, preventable defects, such as lack of immunizations, dental care, screening for common problems, and follow-up had been largely corrected. The substantial decline in absenteeism among study participants clearly shows the effectiveness of the demonstration project in promoting good health by decreasing morbidity and/or decreasing recovery time. Overall, the results of the three-year demonstration project reported here show that a carefully designed, well-coordinated school health program based on a family practice model can have a substantially favorable impact on the health of participating children.

Absenteeism↗
PubMed1991

Bone marrow and peripheral blood findings in patients with extreme thrombocytosis. A report of 63 cases.

Sixty-three bone marrow (BM) and peripheral blood specimens from patients with platelet counts of 1000 x 10(9)/L or greater were examined in an attempt to determine if any BM or peripheral blood findings could be used reliably to distinguish primary thrombocythemia from other myeloproliferative disorders and extreme examples of reactive thrombocytosis. Our results indicated that the BM findings in primary thrombocythemia were quite similar to those in polycythemia vera and chronic granulocytic leukemia with associated extreme thrombocytosis. However, statistically significant differences between the BM findings in myeloproliferative disorders and extreme reactive thrombocytosis were found in the numbers of megakaryocytes, presence or absence of megakaryocyte clusters, stainable iron, cellularity, and reticulin content. We concluded that BM examination is a useful procedure as an aid in determining the cause of extreme thrombocytosis.

Bone Marrow↗
PubMed1990

A phase II trial of high-dose cytarabine and cisplatin in previously untreated non-small cell carcinoma of the lung. A Piedmont Oncology Association Study.

Thirty-seven chemotherapy-naive patients with advanced non-small cell lung cancer (NSCLC) were treated with cytarabine (3 g/m2 intravenously [IV] during 3 hours) after IV bolus cisplatin (100 mg/m2 repeated every 3 weeks). Aside from nausea and vomiting, the principal toxicity was hematologic, with Grade IV myelosuppression in 32% and Grade III in 14%. Four patients died while on study. One complete and four partial responses were observed for an overall response rate of 14%. Responses were limited to lymph node and lung metastases and occurred in two of 17 adenocarcinomas, two of 12 squamous cell carcinomas, and one of eight large cell carcinomas. At this dose, the plasma level of cisplatin is only 3 micrograms/ml and the plasma level of cytarabine is 10 to 50 micrograms/ml, compared with the levels of 10 micrograms/ml and 1000 micrograms/ml, respectively, required for in vitro synergy. The severity of myelotoxicity observed indicates that, even at these levels, cisplatin enhances cytarabine activity. The combination may prove useful in malignancies that are sensitive to cytarabine, but is not of benefit in cytarabine-resistant malignancies such as NSCLC.

Adult↗
PubMed1990

Platinum-based combination chemotherapy in advanced non-small cell lung cancer: a randomized phase II trial of the Cancer and Leukemia Group B.

The Cancer and Leukemia Group B (CALGB) utilized a randomized phase II trial design to evaluate two cisplatin-based combinations, cisplatin-cytarabine (ara-C) and cisplatin-vinblastine, in 151 patients with advanced non-small cell lung cancer. Patients entered on study had not received prior chemotherapy. Platinum doses were equivalent in the two treatment programs. The total response rate (complete response, partial response, regression of evaluable disease) for the cisplatin-vinblastine group was 22% (16/73). Failure-free survival at six months for this group was 41%, survival at six months was 63%. The cisplatin-ara-C group had a total response rate of 9% (7/78) with a failure-free survival at six months of 14% and a six-month survival of 47%. Severe or life-threatening toxicity was seen in 73% of cisplatin-vinblastine cases and 59% of cisplatin-ara-C patients. Neither regimen is active enough to warrant designation as "standard therapy" for patients with M1 disease.

Aged↗
PubMed1990

A phase II trial of PEG-L-asparaginase in the treatment of non-Hodgkins lymphoma.

A polyethylene glycol conjugate of L-asparaginase (PEGLA) was administered to 21 patients with refractory non-Hodgkin's lymphoma. The dose given was 2,000 mu/m2 intramuscularly every 2 weeks. Eligibility required at least one prior trial of chemotherapy and ambulatory performance status. At entry, all patients had measurable lesions and documented disease progression. The median age of the patients was 61 years; 18 (86%) were ambulatory with minimal symptoms, 12 patients (57%) had 3 or more prior regimens, and 13 (62%) had stage IV disease. Histologic subtype was low grade in 11 patients (52%), intermediate in 7 (33%), high grade in 2 (10%) and unclassifiable in one (5%). There were two partial responses (11%) noted (95% confidence interval of response of 1-30%). Eleven patients (52%) were removed from study due to disease progression. Nine patients (43%), required removal for toxicity (7 for protracted nausea and vomiting and 2 for confusion). One patient died of sepsis while on study but this was not considered drug related. Almost one third of patients complained of fatigue or loss of appetite. Nausea and vomiting occurred in approximately half the patients and was moderate to severe in 9. Diarrhea and abdominal pain were also noted in one-third of those treated. Changes in the partial thromboplastin time and fibrinogen were noted in most patients but resulted in no bleeding complications. In this trial, PEGLA displayed modest activity in a heterogenous group of patients with progressive non-Hodgkin's lymphoma.

Adult↗
PubMed1990

Metalloproteases of infective Ancylostoma hookworm larvae and their possible functions in tissue invasion and ecdysis.

To infect their hosts, hookworm larvae must exsheath and migrate through connective tissue. A modified in vitro skin chamber was used to show that the human hookworm Ancylostoma duodenale and the zoonotic canine hookworm Ancylostoma caninum penetrate epidermis, basement membrane, and dermis in similar ways. These similarities in tissue invasion properties reflect the observed biochemical similarities in parasite protease composition. The larvae of both species contain protease activity that is inhibited by o-phenanthroline; this identifies the proteases as metalloproteases. The enzyme activities exhibit an alkaline pH optimum between pH 9 and 10. During modified sodium dodecyl sulfate-polyacrylamide gel electrophoresis in which a protein substrate (either casein or gelatin) was used, the protease activities resolved into a major band at an Mr of 68,000 and a minor band at an Mr of 38,000. Proteases were released by living A. caninum larvae in vitro and degraded purified and radiolabeled casein to smaller peptides. Motile hookworm larvae were also incubated with purified and radiolabeled connective tissue macromolecules in vitro. Both Ancylostoma species degraded human fibronectin to a 60,000-Mr polypeptide intermediate, but could not degrade solubilized bovine elastin or human laminin. In contrast, the obligate skin-penetrating nematode Strongyloides stercoralis degraded all three substrates. This biochemical difference may explain some observed differences in invasiveness.

Ancylostoma↗
PubMed1990

High- versus standard-dose megestrol acetate in women with advanced breast cancer: a phase III trial of the Piedmont Oncology Association.

One hundred seventy-two patients with advanced breast cancer were randomized to receive oral standard-dose megestrol acetate (MA), 160 mg/d or high-dose MA, 800 mg/d. All but two patients had one prior trial of tamoxifen therapy for either metastatic disease (74%) or as adjuvant treatment (26%). Pretreatment characteristics were similar for both arms. High-dose MA resulted in a superior complete plus partial response rate (27% v 10%, P = .005), time to treatment failure (median, 8.0 v 3.2 months, P = .019), and survival (median, 22.4 v 16.5 months, P = .04) when compared with standard-dose therapy. These differences remained significant after adjustment for other covariates. Thirty-four patients were given high-dose MA after failure of standard-dose MA treatment, and none responded. Weight gain was the most distressing side effect, with 13% of standard-dose and 43% of high-dose patients gaining more than 20 lbs. Four major cardiovascular events occurred in patients receiving high-dose treatment and one in patients given standard doses. Other toxicity was modest. High-dose MA may represent a significant improvement in secondary endocrine therapy for advanced breast cancer patients refractory to initial endocrine treatment, but its use on a regular basis should be reserved until these results are confirmed by other clinical trials.

Adult↗
PubMed1990

Vincristine infusion with CHOP-CCNU in diffuse large-cell lymphoma.

Phase I and II trials of vincristine infusion have demonstrated the safety and efficacy of this approach in the treatment of patients with refractory non-Hodgkin's lymphoma. Subsequently, a trial was designed to evaluate this technique in untreated patients. Repeated 5-day infusions of vincristine 0.25 mg/m2 per day were incorporated into a CHOP-CCNU regimen and administered to 24 patients with advanced diffuse large-cell lymphoma. Objective responses occurred rapidly and were observed in 18 (75%) patients in whom 13 (54%) were complete. Toxicity was generally mild to moderate and neurotoxicity appeared to be no worse than typically observed with bolus vincristine. Complete responses have been durable in most patients and 10 (77%) of the complete responders have not relapsed. At this time, 9 (38%) of the total patients remain alive and without evidence of disease from 3.8 to 7.3 years from the start of treatment. One patient died of disseminated gastric cancer at 3.3 years from the start of therapy and there was no evidence of lymphoma at exploratory laparotomy. Infusion of vincristine may be safely incorporated into multiagent chemotherapy programs of the CHOP type for non-Hodgkin's lymphoma. Its potential for protracted nonmyelosuppressive cell kill would appear attractive in designing future trials for this disease.

Adult↗
PubMed1989

Mitoxantrone and high-dose ara-C in refractory malignancies: a phase I trial.

On the basis of in vitro studies demonstrating marked synergy between mitoxantrone and high-dose cytosine arabinoside (ara-C) (HiDAC) against L5178Y murine leukemia and clinical studies showing usefulness of the combination in patients with refractory acute myeloid leukemia, a phase I study was initiated to find tolerable doses for use in patients with refractory solid tumors. Initial dose levels were mitoxantrone 2 mg/m2 infused over 30 minutes, followed by high-dose ara-C 750 mg/m2 infused over 3 hours repeated once at 24 hours (total dose 4 mg/m2 mitoxantrone and 1,500 mg/m2 HiDAC per 2-day course), with planned subsequent escalation of mitoxantrone. Moderate-to-severe myelosuppression, however, required sequential dose reduction of both agents. Nonhematologic toxicity was restricted to manageable nausea and vomiting in one-half the patients and a single episode of transient delirium of uncertain etiology. No responses were observed in 23 heavily pretreated patients with a wide variety of malignancies. On the basis of this study, doses of 187-375 mg/m2 ara-C given every 24 hours for two doses following mitoxantrone 1 mg/m2 every 24 hours for two doses would be tolerated by most patients with subsequent dose escalation in some as allowed by myelosuppression.

Adult↗
PubMed1989

Phase I study of vincristine and escalating doses of etoposide.

A phase I trial of vincristine and etoposide was designed following the identification of a potentially synergistic antitumor effect in a murine model. The dose of vincristine was fixed (0.5 mg daily for 3 days). Etoposide was given at 1 of 3 total dose levels (250, 500, or 750 mg/m2) per treatment. Each dose was given in 3 equal fractions and each fraction was given daily for 3 days, i.e., 83.3 mg/m2/d x 3d, 166.7 mg/m2/d x 3d, or 250 mg/m2/d x 3d. A total of 31 patients were entered into study including 10, 18, and 3 patients treated at the 250, 500, and 750 mg/m2 dose levels, respectively. Dose-limiting toxicity occurred at the 750 mg/m2 level, in which Grade 4 myelosuppression developed in all of the patients. Life-threatening gram negative sepsis occurred in two of these patients and both required platelet transfusions. Grade 3-4 WBC toxicity was observed in 9 of 16 (56%) evaluable patients treated at the 500 mg/m2 level, but reversal of toxicity was generally rapid with repeat courses given at 3 week intervals in most patients. Non-hematologic toxicity was negligible. Objective responses were observed in 2 of 4 patients with Hodgkin's disease. The starting dose of etoposide recommended for phase II trials of this agent in combination with vincristine is 500 mg/m2; dose escalation may be possible in some patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

Effect of praziquantel on the eggs of Schistosoma mansoni, with a note on the implications for managing central nervous system schistosomiasis.

The morphology of Schistosoma mansoni eggs in intestinal tissues (oograms), and egg hatching in faeces, were studied after parenteral administration of praziquantel (PZQ) to infected mice. PZQ was given parentally in doses of 60 mg kg-1 for one day, five days or 10 days. Eleven days after initiation of therapy, oograms from all groups receiving PZQ showed more dead eggs than controls; a dose response was also observed. Depression of faecal egg hatching occurred within 24 hours of PZQ administration. Our observations suggest that PZQ kills most S. mansoni eggs in host tissues when administered in higher doses than are routinely recommended for treatment of intestinal schistosomiasis mansoni. In order to reduce the lifespan of metabolically active eggs in sensitive tissues, prolonged courses of PZQ could be used when treating central nervous system schistosomiasis.

Animals↗
PubMed1989

Surveillance: the foundation for control and elimination of dracunculiasis in Africa.

The International Drinking Water Supply and Sanitation Decade (1981-1990) has stimulated a movement to eradicate human infection with the helminthic parasite Dracunculus medinensis (dracunculiasis), whose victims are disabled for weeks or months during the painful emergence of one or more worms from beneath the skin. Each year, millions of people acquire this infection by drinking unclean water. Among the critical activities that are necessary for the elimination of dracunculiasis, one of the most fundamental is that of epidemiological surveillance. Surveillance activities play a key role in the strategy to target affected villages for improved water supplies and other control activities. Accurate surveillance data also stimulate interest and support for national eradication programmes. Dracunculiasis is a condition with excellent characteristics for reporting through passive surveillance systems. However, active surveillance, as well as other innovative surveillance strategies, should be used to establish baseline information in those villages where cases occur, and later to monitor epidemiologically important indices needed to evaluate the progress of elimination efforts.

Africa↗
PubMed1989

Chemoinfusion of the hepatic artery for metastases to the liver.

During a five year period, 69 patients were treated for carcinoma of the liver (seven primary tumors and 62 metastatic tumors) with 5-fluorodeoxyuridine (5-FUDR) administered through a hepatic artery (n = 62) or portal vein (n = 3) implantable infusion pump. Ten patients proved to have previously unsuspected extrahepatic nodal metastases at laparotomy for pump insertion. 5-FUDR was given in 14 day cycles for three months. At the end of that period and at three month intervals thereafter (mean follow-up time of 18 months, a range of one to 60 months), patients were evaluated with roentgenograms of the chest, liver function tests, carcinoembryonic antigen levels, radionuclide scans and computed tomography. Thirty-five patients had a partial response, nine had stabilization of the disease and 25 had progression of the disease (five during therapy, who were given mitomycin C). Median regression was 6.8 months (a range of three to 18 months). Six of the 35 partial responders, three of the nine patients with stabilization and ten of the 25 patients with progression had extrahepatic visceral disease. Survival time averaged 18.4 months (a range of five to 60 months) for the partial responders, 12.6 months (a range of two to 40 months) for patients with stabilization and seven months (a range of one to 17 months) for those with progression of the disease.

Adult↗
PubMed1989

Low-dose ara-C therapy for acute myelogenous leukemia in elderly patients.

Forty-four evaluable patients with untreated acute myelogenous leukemia received twice-daily subcutaneous injections of low-dose ara-C (10 mg/m2) for less than or equal to 42 days. The median age was 72 years (range 53-87); 42 of 44 patients were greater than or equal to age 60. Ten patients (23%) had complete responses with a median duration of 9.9 months. Median survival was 3 months (range 0.6-31.2+) for all patients, and 19.5 (range 7.9-31.2+) for patients who attained complete responses. Cytoreduction occurred slowly with low-dose ara-C and five of ten patients who achieved complete remission did not develop marrow aplasia. Toxicity was predominantly related to infections associated with granulocytopenia. Nonhematologic toxicity was limited. Low-dose ara-C as used in this trial results in a complete response rate and a duration of response similar to those achieved with other treatments in elderly patients, but with reduced toxicity.

Aged↗