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Biomedical subjects

R Couch

Publications and source records attributed to R Couch.

At least 19 recordsLinked to original sources
PubMed1999

Rhinovirus infections in myelosuppressed adult blood and marrow transplant recipients.

Scant data are available on the clinical significance of rhinovirus infections in immunocompromised patients. We reviewed the clinical courses of and outcomes for 22 myelosuppressed adult blood and marrow transplant recipients with rhinovirus infections who were hospitalized at the M.D. Anderson Cancer Center (Houston) from January 1992 to January 1997. In 15 patients (68%), illnesses remained confined to the upper respiratory tract. Seven patients (32%) developed fatal pneumonia. These patients had profound respiratory failure a mean of 12 days (range, 3-21 days) after the onset of symptoms. In six of these seven cases, rhinovirus was isolated before death from a bronchoalveolar lavage fluid specimen and/or an endotracheal aspirate. Five patients underwent autopsies, one of which revealed disseminated aspergillosis and four of which revealed interstitial pneumonitis and/or acute respiratory distress syndrome and no other organisms. In conclusion, rhinovirus infections may be associated with considerable pulmonary-related morbidity and mortality in severely myelosuppressed immunocompromised patients.

Adult↗
PubMed1997

Influenza among hospitalized adults with leukemia.

Influenza is one of the most important respiratory diseases of mankind, yet scant data exist concerning the frequency and clinical course of influenza in severely immunocompromised adults. From October 1993 to September 1994, we cultured the respiratory secretions of all adults with leukemia who were hospitalized with an acute respiratory illness at The University of Texas M.D. Anderson Cancer Center in Houston. During a 9-week period from 29 November 1993 to 29 January 1994, influenza virus type A (H3N2) was isolated from 15 (33%) of these 45 hospitalized adults. Twelve (80%) of the cases of influenza were associated with pneumonia, and four patients (33%) with pneumonia died. Patients who died tended to have received chemotherapy more recently and to be more myelosuppressed. Autopsy examination in two cases revealed histopathologic changes consistent with viral pneumonia. During community outbreaks, influenza is a frequent cause of serious respiratory disease in hospitalized adults with leukemia. Effective prophylactic and therapeutic regimens need to be defined for immunocompromised patients.

Adult↗
PubMed1996

In vivo dosimetry of ethylene oxide and propylene oxide in the cynomolgus monkey.

In mammals, including the cynomolgus monkey, a striking difference between the potencies of ethylene oxide (EO)* and propylene oxide (PO) with respect to induction of certain clastogenic effects has previously been observed. In order to clarify to what extent such differences can be ascribed to a difference in detoxification rate, cynomolgus monkeys were administered an equimolar mixture of the two epoxides at two dose levels, and the blood doses were determined by measurement of the degree of alkylation of N-terminal valines in hemoglobin (Hb). For the highest exposure a saturation in the detoxification of PO was evident from a marked increase in adduct level. At the lower exposure, the dose in blood resulting from exposure to PO was about one fourth of that from EO. Although playing a great role, differences in detoxification rate, therefore, cannot fully account for the much lower clastogenic potency of PO, which has been found in earlier studies. Furthermore, the determination of doses in blood gives data on relationship between in vivo dose and exposure dose (accounting for detoxification), with relevance for risk estimation.

Alkylation↗
PubMed1996

Respiratory disease due to parainfluenza virus in adult bone marrow transplant recipients.

We reviewed the frequency and clinical course of parainfluenza virus (PIV) infections in 1,173 adult bone marrow transplant (BMT) recipients cared for at The University of Texas M.D. Anderson Cancer Center (Houston). Between January 1991 and September 1994, PIV was isolated from the respiratory secretions of 61 (5.2%) of these patients. Thirty-four (56%) of the 61 patients had uncomplicated upper respiratory tract illnesses and survived. The remaining 27 patients (44%) developed pneumonia, and the associated mortality was 37% (10 of 27 patients). Twenty-three (85%) of the patients with pneumonia had had preceding upper respiratory illnesses. Of the 10 patients who died, nine died within 100 days after transplantation. Histopathologic examination of lung tissue from seven patients revealed intracytoplasmic viral inclusions in six, a finding consistent with invasive PIV pneumonia, and viral changes in the seventh patient. Seven of the 10 patients who died had other serious concurrent infections. Of 42 patients who developed PIV infection early after transplantation (i.e., < 100 days), the frequency of pneumonia was higher among the 18 allogeneic BMT recipients (61%) than among the 24 autologous BMT recipients (42%), and the associated mortality was also higher (55% vs. 30%, respectively). PIVs are an important cause of life-threatening pneumonia in adult BMT recipients, particularly patients who have recently undergone allogeneic bone marrow transplantation.

Adult↗
PubMed1996

Comparison of US inactivated split-virus and Russian live attenuated, cold-adapted trivalent influenza vaccines in Russian schoolchildren.

In a blinded, placebo-controlled study, the reactogenicity, immunogenicity, and clinical efficacy of single doses of US inactivated split-virus and Russian live attenuated, cold-adapted influenza vaccines were compared in 555 schoolchildren in Vologda, Russia. Serial serum samples were collected and school absenteeism was assessed. Systemic reactions were rare, but local reactions (primarily erythema at the injection site) were observed in 27% of the inactivated vaccine group, and coryza (12%) and sore throat (8%) were observed in the attenuated vaccine group. At 4 weeks after vaccination a > or = 4-fold rise in titer of hemagglutination inhibition antibody to A (H1N1), A (H3N2), and B was noted, respectively, among 78%, 88%, and 53% of children who received inactivated vaccine and among 55%, 79%, and 30% of children who received attenuated vaccine. The vaccine efficacy for preventing school absenteeism due to respiratory illness during the period of peak influenza activity was 56% for inactivated vaccine and 47% for attenuated vaccine.

Antibodies, Viral↗
PubMed1995

Lack of methylation of inorganic arsenic in the chimpanzee.

Most mammals methylate inorganic arsenic (As) to methylarsonic acid (MMA) and dimethylarsinic acid, which are rapidly excreted in the urine. Previous studies have shown that, in contrast to humans, all experimental animals excrete very little MMA. With the aim of finding an appropriate animal model for studies on inorganic As metabolism and toxicity, we have investigated the metabolism of As in two male chimpanzees after a single iv dose of [73As]arsenate (5.8 micrograms As/kg body wt). The initial clearance from plasma was rapid with an apparent half-time of about 1 hr. Urine was found to constitute the major excretory pathway with very little excretion in the feces. About 60% of the administered 73As dose was excreted in the urine within 96 hr in a biphasic manner. The second phase of slow urinary excretion was characterized by first-order kinetics with a half-time of about 7 days. Upon ion-exchange chromatography of ultrafiltrated plasma and urine, only inorganic As could be detected, a finding confirmed by thin-layer chromatography. Thus, the results indicate that the chimpanzee, as previously shown for the marmoset monkey, but unlike all other mammals studied so far, including humans, is unable to methylate and detoxify inorganic As.

Animals↗
PubMed1995

Epidemiology of influenza A virus infection in patients with acute or chronic leukemia.

Influenza infection is a significant cause of morbidity and mortality in immunocompromised hosts, but its importance in adult cancer patients is largely undescribed. We therefore conducted a prospective study of the incidence and clinical features of influenza infection in patients with acute or chronic leukemia. The cohort, which consisted of all adult leukemia patients undergoing remission-induction chemotherapy during the 1991-1992 influenza epidemic, was followed prospectively for development of signs and symptoms of acute infection of the upper or lower respiratory tract. Of these 294 patients, 111 received chemotherapy as inpatients and 183 as outpatients. Throat swabs and nasal washes for viral culture were obtained from all symptomatic patients, who were then followed until all signs and symptoms resolved. Symptoms of respiratory tract infection developed in 37 leukemia patients (13%). Among these, influenza (A/Beijing/ H3N2) caused 3 (21%) of the 14 infections that developed during hospitalization but only 1 (4%) of the 23 that developed in the community (P = 0.14). Influenza patients presented with fever, rhinorrhea, nasal congestion, headache, and myalgia; those with other infections presented with signs and symptoms of lower respiratory tract infection (productive cough, rales, or rhonchi). Development of pneumonia was common in influenza patients, 1 of whom died from secondary fungal and gram-negative pneumonia. Influenza A virus infections accounted for a substantial portion of acute respiratory infections among adult leukemia patients during a community epidemic. Most infections appeared to be nosocomial and the most likely sources were visitors or hospital personnel. Immunization of household contacts and hospital staff may reduce the risk of influenza infection and its pulmonary complications in leukemia patients.

Acute Disease↗
PubMed1995

Fetal thyrotoxicosis: a case report and recommendations for prediction, diagnosis, and treatment.

A maternal history of Graves' disease places the fetus at risk for thyrotoxicosis in utero via the placental transfer of thyroid-stimulating immunoglobulins. Methods for prediction of fetal hyperthyroidism are available, but are not widely used. Clinical assessment of fetal thyroid status by monitoring of fetal heart rate and growth may be inaccurate. This raises some uncertainty in the initial diagnosis of fetal thyrotoxicosis and complicates the assessment of fetal response to maternal propylthiouracil therapy. A case illustrating these pitfalls in the diagnosis and management of fetal hyperthyroidism is presented. The condition was correctly diagnosed, but treatment based on fetal heart rate resulted in biochemical hypothyroidism in the infant at birth. Current recommendations for diagnosis and treatment of fetal hyperthyroidism are reviewed along with recent developments in the field. A modified approach is proposed.

Adult↗
PubMed1993

Antibody response to a two-dose influenza vaccine regimen in adult lymphoma patients on chemotherapy.

A study was conducted to determine if a two-dose regimen of influenza vaccine would enhance the immunologic response of 41 patients with lymphoma receiving chemotherapy. Hemagglutinin-inhibiting antibody responses to influenza A/H1N1, A/H3N2 and B virus occurred in 32%, 24% and 20% of patients following one dose, and in 49%, 41% and 46% of patients following two doses, respectively. Responses to one or more vaccine components occurred in 42% of patients after one dose and in 71% after two doses. Fifty percent of the patients who did not respond after one dose responded after two doses. A two-dose regimen of influenza immunization may significantly enhance the response rate of cancer patients receiving chemotherapy.

Adult↗
PubMed1993

Pilot evaluation of influenza virus vaccine (IVV) combined with adjuvant.

The safety of licensed influenza virus vaccine (IVV) combined with a novel adjuvant containing muramyl tripeptide (MTP) conjugated to phosphatidylethanolamine (PE) was evaluated in a randomized pilot study. Ten healthy 23-30-year-old men were given a single intramuscular dose of IVV combined with saline (n = 5) or with 100 micrograms of MTP-PE in the MF59 adjuvant emulsion (MF59-100) (n = 5). Evaluations were performed on days 0, 1, 2, 4, 7 and 28 after inoculation. IVV alone was well tolerated. All volunteers immunized with IVV/MF59-100 experienced moderate to severe local and systemic reactions which interfered with usual activities. Discomfort at the injection site was first noted at 2-6 h; induration (5/5), erythema (3/5), and regional adenopathy (3/5) persisted for up to 4 days. Systemic symptoms including chills (5/5), fever (3/5), nausea (3/5) and/or dizziness (2/5) developed within 12 h of inoculation and resolved by 48 h. Elevated white blood cell count (days 1 and 2), erythrocyte sedimentation rate and serum fibrinogen were transiently observed. Although peak serum neutralizing antibody titres versus influenza A/H3N2 and influenza B antigens were higher in the group given IVV with MF59-100, these unexpected reactions indicate that this dose of adjuvant is unsuitable for use in combination with this IVV.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1993

Theophylline target concentration in severe airways obstruction - 10 or 20 mg/L? A randomised concentration-controlled trial.

The optimal serum concentration of theophylline for the management of acute airways obstruction was evaluated by comparing the response to target concentrations at the extremes of the usual therapeutic range. 174 patients requiring intravenous theophylline were randomly assigned to a target concentration of 10 or 20 mg/L. Control of theophylline dosage using measured theophylline concentrations and evaluation of efficacy and toxicity was performed under double-blind conditions. 87 patients (50%) required hospital admission. Of these, 54 patients (62%) were followed throughout their hospital admission and reviewed at an outpatient clinic approximately 1 week after discharge. The duration of hospital stay, and rate and extent of improvement in peak expiratory flow rate were not different between the groups. There was significantly more toxicity in the 20 mg/L group. The initial target concentration for theophylline in the management of acute airway obstruction should be 10 mg/L under circumstances where concentration is used to control theophylline dosages.

Adult↗
PubMed1985

The changing picture of pseudotumor cerebri in children.

Among 38 children with pseudotumor cerebri only 3 cases were due to ear disease or its complications. The commonest cause was a refeeding syndrome either due to nutritional deprivation or as an early finding in the treatment of cystic fibrosis. It is uncommon to find the cause of pseudotumor in older children but in those under 6 years the cause was found in 85%. Because of the adverse effects of steroids we use this treatment in the more resistant cases.

Adolescent↗
PubMed1975

Suturable gastrointestinal cannulas for animals of various sizes.

A new procedure in which gastrointestinal cannulas are prepared from suturable material improves in vovo methods and requires little machining. Substitution of a suturable material for rigid collars, previously used, prevents leakage, infection, and loss of the cannulas into the gut lumen. The technique has been successfully applied to rats, rabbits, and dogs; consequently it should be useful in animals of almost any size. Two designs of cannulas with descriptions of their implantation are presented. The first version fits into each end of a gut loop and is useful for perfusion, digestion, and secretion studies. The second version forms a sidearm through which feeding or sampling can be carried out at any point in the intestine or the stomach.

Animals↗