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Biomedical subjects

M Atkins

Publications and source records attributed to M Atkins.

52 records · Page 3Linked to original sources
PubMed1991

Environmental contamination during tracheal suction. A comparison of disposable conventional catheters with a multiple-use closed system device.

The extent of airborne environmental bacterial contamination which occurs following tracheal suction has been investigated in patients undergoing intermittent positive pressure ventilation in the intensive therapy unit. Two methods of performing suction, one using a conventional open technique and one using a closed system (Stericath), have been compared. Significantly lower levels of environmental contamination were observed when the closed system was used.

Air Microbiology↗
PubMed1991

Phase II trial of fluorouracil and recombinant interferon alfa-2a in patients with advanced colorectal carcinoma: an Eastern Cooperative Oncology Group study.

In a pilot clinical trial, treatment of patients with advanced colorectal carcinoma with the combination of fluorouracil (5FU) and recombinant interferon alfa-2a (IFN) resulted in objective tumor regression in 62% of patients. To confirm these findings in a multiinstitutional setting, a phase II clinical trial was initiated by the Eastern Cooperative Oncology Group (ECOG) in 1989. The treatment regimen was identical to that used in the earlier study: 5FU 750 mg/m2/d for 5 days as a continuous infusion followed by weekly outpatient bolus therapy and IFN 9MU subcutaneously beginning day 1 and administered three times per week. Doses were modified for gastrointestinal, hematologic, and neurologic toxicity and for fatigue, similarly to those used in the previous pilot trial. Thirty-eight patients were registered; 36 are evaluable for response (one lost to follow-up and one with nonmeasurable disease). All patients had metastatic or locally recurrent disease beyond the scope of resection; 31 of 38 had liver metastases, and 20 of 38 had two or more sites of involvement. Eight patients had grade 4 toxicities, including sepsis (nonneutropenic) (one), watery diarrhea (two), and granulocytopenia (six). Grade 3 neurologic toxicities were observed in two (5%) patients and included slurred speech and gait disturbance. Objective response was 42% (95% confidence interval [Cl], 27% to 58%), including one clinical complete responder and 14 partial responders. Among the responding patients, the median time to treatment failure was 8 months. Two patients remain on treatment at 10+ and 16+ months: median survival has not been reached. The results of this multiinstitutional trial suggest that the addition of IFN to 5FU enhances the objective response rates achieved in patients with advanced colorectal carcinoma and that the toxicities of this regimen are acceptable.

Adult↗
PubMed1990

An outbreak of hepatitis A among cancer patients treated with interleukin-2 and lymphokine-activated killer cells.

An outbreak of hepatitis A virus (HAV) infection occurred among cancer patients treated with interleukin-2 (IL-2) and lymphokine-activated killer (LAK) cells between July and September 1986 at six different clinical centers. Among 85 patients tested serologically for recent HAV infection, 22 (39%) of 56 susceptible patients developed acute HAV infection. Only exposure to LAK cells cultured in medium containing human serum from two specific manufactured pools was associated with HAV infection. Attack rates were 85% among patients exposed to pool X, 62% in patients exposed to pool Y, and 50% in those exposed to both pools, compared with none among the 24 susceptible persons exposed to other serum pools (P less than .001). The serum used in production of LAK cell medium was obtained from multiple paid donors. Twenty persons donated plasma to both serum pools X and Y. Although none of 12 donors tested had evidence of recent HAV infection, it is likely that an asymptomatic plasma donor viremic for HAV contaminated both serum pools and the LAK cell medium made from it.

Animals↗
PubMed1990

Melanotropin receptors demonstrated in situ in human melanoma.

Although some cultured human melanoma cell lines are responsive to melanotropins (melanocyte-stimulating hormones [MSH]), the prevalence and tissue distribution of MSH receptors in melanoma are unknown. We report here the use of an in situ binding technique to demonstrate specific MSH receptors in surgical specimens of human melanoma. The distribution and binding properties of specific MSH binding sites were determined by autoradiography and image analysis after incubation of frozen tumor tissue sections with a biologically active, radiolabeled analogue of alpha-MSH, [125I]iodo-Nle4, D-Phe7-alpha-MSH ([125I]NDP-MSH). In melanoma specimens from 11 patients, 3 showed high levels of specific binding, 5 showed low levels, and in 3 patients specific binding of [125I]NDP-MSH was not detectable. Specific MSH binding sites were present in melanoma cells, but not in adjacent connective or inflammatory tissues. Melanotropins, including alpha-MSH, NDP-MSH, and ACTH, inhibited [125I]NDP-MSH binding in a concentration-dependent manner, whereas unrelated peptides (somatostatin and substance P) did not. The apparent affinity of alpha-MSH for this binding site was in the nanomolar range (EC50 = 2 X 10(-9) M for inhibition of [125I]NDP-MSH binding in situ), similar to that recently described for the murine melanoma receptor. In one patient, analysis of multiple intratumor samples and tumors excised on three separate occasions revealed high levels of specific MSH binding in all samples. These results suggest that endogenous melanotropins may modulate the activities of human melanoma cells in vivo.

Autoradiography↗
PubMed1990

Soft neurological signs and impulsivity in children.

To evaluate the relationship between soft neurological signs and various proposed dimensions of impulsivity (behavioral and cognitive), 31 boys (6-13 years, mean +/- SD 10.1 +/- 1.8) with disruptive behavior disorders, and 45 age-matched boys without DSM-III-R pathology, were independently assessed on clinical ratings of impulsivity, a battery of cognitive tests intended to score impulsive responding, and a neurological examination for soft signs. After being corrected for age, neurological soft signs correlated positively with impulsive responding on the Matching Familiar Figures Test (inpatients and normals) and the Continuous Performance Test (in normals), but not with IQ or clinical impulsivity rating scores. These findings suggest a relationship between neurological dysfunction/immaturity and performance on specific tasks requiring response inhibition, thus adding value to the cognitive assessment of impulsivity.

Adolescent↗
PubMed1977

Potentiation of pulmonary vasoconstrictor response with repeated intermittent hypoxia.

To determine the consistency of the pulmonary vasoconstrictor response to hypoxia, dogs were anesthetized, intubated, and ventilated alternately with air and 10% oxygen. Catheters were placed in the pulmonary artery for measurement of pulmonary artery pressure (PAP), pulmonary capillary wedge pressure, and cardiac output and in the femoral artery for monitoring systemic blood pressure and arterial blood gases. Arterial PCO2 and pH were kept at steady levels throughout by ventilating the dogs with a respirator so that only the isolated effect of hypoxia on the pulmonary vasculature was studied. It was found that there was a progressive rise in the PAP with repeated exposure to the same hypoxic stimulus. In 12 dogs, the mean increase in the PAP was 28% above the base line on the 1st hypoxic exposure, rising to 99% by the 10th exposure over the course of 5 h. It was concluded that interpretation of action of agents blocking or enhancing the hypoxic response must take into account this inherent potentiation of the response on repeated exposure to hypoxia.

Animals↗
PubMedDate not supplied

Natural history of untreated cytomegalovirus retinitis.

Cytomegalovirus infection is common in patients with AIDS, and often causes retinitis. Treatment is rarely curative, but the progression of retinitis is delayed. The untreated course of cytomegalovirus retinitis in AIDS is unknown. We report a 35-year-old man with retinitis who refused treatment. Retinitis resulted in blindness within 6 months. Measurement of cytomegalovirus genomes showed an increasing viral load in blood and urine.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Outpatient subcutaneous interleukin-2 and interferon-alpha for metastatic renal cell cancer: five-year follow-up of the Cytokine Working Group Study.

PURPOSE: A phase II trial of outpatient subcutaneous (SC) interleukin-2 (rIL-2) plus interferon-alpha (IFN-alpha 2B) was performed in patients with metastatic renal cell cancer. A 5-year follow-up of that Cytokine Working Group study is presented. PATIENTS AND METHODS: Forty-seven patients meeting eligibility criteria of previous Cytokine Working Group studies were treated on an outpatient basis with SC rIL-2 (Chiron, Emeryville, CA), 5 x 10(6) IU/m2/dose q 8 hr x 3, then daily, 5 days per week, and IFN-alpha 2B (Schering-Plough, Kenilworth, NJ), 5 x 10(6) IU/m2/dose three times weekly for 4 weeks. After a 2- to 4-week break, patients were scheduled to continue treatment for up to six cycles. RESULTS: There were two complete and six partial responders (17% response rate, 95% CI: 8%-31%). Median duration of response was 12 months (range 1-49+ months), with complete responses of 15 and 49+ months. Responding sites of disease included lung, nodes, soft tissue, bone, and liver. Dose and schedule were adjusted to control toxicity at grade 2/3 levels, with 50% requiring dosage alterations. Grade 2/3 toxicity included fatigue, nausea/vomiting, diarrhea, anorexia, fluid overload, rash, CNS, injection site pain, chest pain/palpitations (including atrial fibrillation requiring treatment, two patients), and hypotension. Grade 4 toxicity included dehydration (seven patients), vomiting (one patient), and irreversible renal failure with crescentic glomerulonephritis requiring dialysis (one patient). CONCLUSION: SC rIL-2 plus IFN-a2B is tolerated in the outpatient setting with frequent dose adjustments. The overall response rate of this regimen is similar to that seen with high-dose rIL-2 alone; however, the response duration appears to be shorter.

Adult↗
PubMedDate not supplied

Clinical trial of weekly intensive therapy with 5-fluorouracil on two different schedules combined with interferon alpha-2a and filgrastim in patients with advanced solid tumors: Eastern Cooperative Oncology Group Study P-Z991.

PURPOSE: The hematopoietic growth factor filgrastim has been shown to reduce both chemotherapy-induced myelosuppression and mucosal toxicities. The aim of this study was to conduct four separate pilot trials to determine the maximum-tolerated doses at which interferon alpha (IFN alpha) followed by 5-fluorouracil (5-FU) could be administered in combination with filgrastim support. PATIENTS AND METHODS: Patients were required to have a histologically documented solid tumor with either measurable or evaluable lesions. All patients were fully ambulatory; had adequate bone marrow, renal, and hepatic function; had recovered from surgery; and gave informed consent. Trials were conducted sequentially. In parts A and B, patients received 5-FU as a continuous intravenous infusion daily for 5 days, followed by weekly bolus therapy at the same dose. In parts C and D, patients received 5-FU as a weekly high-dose, 24-hour infusion. Interferon was administered immediately before the 5-FU three times a week. Filgrastim was administered at 5 micrograms/kg subcutaneously either four (parts A, B) or five (parts C, D) times a week. In part A, the starting doses were as follows: 5-FU, 750 mg/m2, and IFN alpha, 3 MU subcutaneously, and the IFN alpha was escalated between patient cohorts to a maximum of 9 MU. Part B used the dose of IFN alpha established from part A, and the 5-FU was escalated to the maximum-tolerated dose between patient cohorts. In part C, the starting dose of IFN alpha was 3 MU subcutaneously, and that of 5-FU, 2.6 g/m2, and the dose of IFN alpha was escalated to a maximum of 9 MU. In part D, the dose of IFN alpha was determined from part C, and the dose of 5-FU was escalated. The maximum tolerated dose was the highest dose at which three of three or five of six patients were able to tolerate therapy. RESULTS: There were 71 patients entered into the four parts of this trial. In part A (12 patients), the dose of IFN alpha, was escalated to 9 MU subcutaneously three times a week with only one patient experiencing dose-limiting toxicity. In part B (13 patients), the dose of 5-FU could not be escalated beyond 750 mg/m2 because of sepsis (one patient) and gastrointestinal hemorrhage (one patient). The predominant toxicities were diarrhea (46%), vomiting (23%), and mucositis (31%). In part C (24 patients), two patients experienced dose-limiting toxicities (staphylococcal sepsis [one patient] and neuropsychiatric [one patient]). The dose of IFN alpha was escalated to 9 MU. In part D (21 patients), the dose of 5-FU was escalated to 3.4 g/m2 administered weekly. No patients at this dose level experienced serious toxicities. At the next highest dose level, 3.6 g/m2, one patient each experienced gastrointestinal hemorrhage and diarrhea. There were no additive constitutional symptoms resulting from the combination of IFN alpha and filgrastim. In parts C and D, filgrastim could be administered 6 hours after the end of the 5-FU infusion without excessive myelosuppression. CONCLUSIONS: The addition of filgrastim allowed escalation of the dose of 5-FU on the weekly, high-dose schedule, but not on the weekly bolus schedule. IFN alpha and filgrastim can be administered without additive toxicities. Filgrastim can be safely administered < 24 hours after completion of the weekly, high dose 5-FU infusion.

Adult↗