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Biomedical subjects

R Morrow

Publications and source records attributed to R Morrow.

At least 37 records · Page 2Linked to original sources
PubMed1989

Left ventricular shape, afterload and survival in idiopathic dilated cardiomyopathy.

Because idiopathic dilated cardiomyopathy is characterized by elevated wall stress and a more spherical left ventricle, the relations among shape, afterload and survival were examined. Thirty-six patients with cardiomyopathy were prospectively studied by two-dimensional echocardiography. Data included echocardiographic short- and long-axis cavity dimensions, their ratio and, with cuff systolic blood pressure, meridional and circumferential end-systolic stress and their ratios. Survivors (n = 16) were followed up for 52 months (range 40 to 76); nonsurvivors (n = 20) died an average of 11 months after study. Survivors had a smaller left ventricular end-diastolic short-axis dimension (6.4 versus 7.1 cm, p less than 0.03) but a similar long-axis length (8.6 versus 8.3 cm). However, overall cavity shape or the ratio of short- to long-axis end-diastolic dimensions was more spherical in those with poorer survival (ratio 0.76 versus 0.68, p less than 0.02). Meridional and circumferential end-systolic stresses were similar in the two groups, but stress was more evenly distributed in the long- and short-axis planes in nonsurvivors (meridional/circumferential stress ratio 0.57 versus 0.52 in survivors, p less than 0.05). Improved survival was associated with an end-diastolic short-axis dimension less than 7.63 cm, a short- to long-axis ratio less than 0.76 and a meridional to circumferential stress ratio less than 0.54. Life table analysis revealed a 28% mortality rate in patients with all three of these characteristics compared with 100% in patients with none. Survivors and nonsurvivors did not differ in systolic cavity dimension, wall thickness, relative wall thickness, cavity volume, percent posterior wall thickening or fractional shortening.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Doppler ultrasound fetal velocimetry and its role in obstetrics.

Abnormal waveforms are seen in association with intrauterine growth restriction, but so far, using the Doppler technique as a screening test to identify unrecognized cases has been disappointing. The waveform changes appear to be associated with a reduced number of small fetal arterioles in the fetal placenta. The interpretation of waveforms is still uncertain and should not be used as a basis for management but rather to increase fetal surveillance by conventional means.

Female↗
PubMed1989

A school-based program to increase seatbelt use.

To improve rates of seatbelt use in young school children and their parents, a curricular intervention was evaluated in a before-after trial over a 15-week period. A public school for pre-kindergarten through second grade (ages 4 to 8 years) in Yonkers, New York, was studied; all of 422 students were included and finished the study. A sequential group of parent drivers were also evaluated, although they were not subject to active intervention. All students were involved in a month-long curricular intervention to raise their awareness of seatbelt use and car safety ("May is Buckle-up Month"). Independent professional observers measured seatbelt use in a nonblinded manner before the intervention, after the intervention, and 1 month after the intervention. Belt use among students increased from 46% to 66% (P less than .01), and stayed at 63% at follow-up, although boys showed an insignificant change. Parent use improved from 47% to 61% (P less than .01), and remained at 62% at follow-up. Intensive curricular exposure to the use of seatbelts can measurably improve the use of belts by young school children. Parental behavior also shows a marked improvement. Such interventions can be organized by community health practitioners, including those in full-time practice, with minimal funding.

Adult↗
PubMed1988

Umbilical and uterine artery blood flow velocities after vibratory acoustic stimulation.

Twelve healthy pregnant women between 37 and 41 weeks' gestational age were studied to determine the effects of external vibratory acoustic stimulation on the blood flow velocity waveform in the umbilical and uterine arteries. There was a significant decrease in umbilical peak-systolic/end-diastolic ratio during the first 5 minutes after stimulus after comparison with control ratios. Analysis of the frequency distribution of instantaneous fetal heart rate values during Doppler measurements suggested that the decrease in umbilical peak-systolic/end-diastolic ratio was due to fetal tachycardia rather than a change in the placental vascular resistance. The uterine artery peak-systolic/end-diastolic ratio was not altered after vibratory acoustic stimulation.

Acoustic Stimulation↗
PubMed1988

Cultural systems for growing potatoes in space.

Higher plants are being evaluated for life support to provide needed food, oxygen and water as well as removal of carbon dioxide from the atmosphere. The successful utilization of plants in space will require the development of not only highly productive growing systems but also highly efficient bioregenerative systems. It will be necessary to recycle all inedible plant parts and all human wastes so that the entire complement of elemental compounds can be reused. Potatoes have been proposed as one of the desirable crops because they are 1) extremely productive, yielding more than 100 metric tons per hectare from field plantings, 2) the edible tubers are high in digestible starch (70%) and protein (10%) on a dry weight basis, 3) up to 80% of the total plant production is in tubers and thus edible, 4) the plants are easily propagated either from tubers or from tissue culture plantlets, 5) the tubers can be utilized with a minimum of processing, and 6) potatoes can be prepared in a variety of different forms for the human diet (Tibbitts et al., 1982). However potatoes have a growth pattern that complicates the development of growing the plants in controlled systems. Tubers are borne on underground stems that are botanically termed 'rhizomes', but in common usage termed 'stolons'. The stolons must be maintained in a dark, moist area with sufficient provision for enlargement of tubers. Stems rapidly terminate in flowers forcing extensive branching and spreading of plants so that individual plants will cover 0.2 m2 or more area. Thus the growing system must be developed to provide an area that is darkened for tuber and root growth and of sufficient size for plant spread. A system developed for growing potatoes, or any plants, in space will have certain requirements that must be met to make them a useful part of a life support system. The system must 1) be constructed of materials, and involve media, that can be reused for many successive cycles of plant growth, 2) involve a minimum quantity of media, 3) contain media that is essentially inert and not oxidize or degrade with use, 4) utilize a recirculating nutrient solution to permit regulation of pH and nutrient concentrations, and 5) be capable of complete automation of all planting, maintenance and harvesting procedures.

Ecological Systems, Closed↗
PubMed1986

Dental pathology of prehistoric residents of Oregon.

Dentitions of 208 prehistoric skeletal specimens from five geographic regions of Oregon were studied to describe their dental status. Comparisons were made of the incidence of specific pathologies among regions and between jaws. Maxillary premortem tooth losses were significantly higher than mandibular tooth loss. A relatively high caries incidence occurs in samples from the Willamette Valley and Klamath Basin, where plant foods were used aboriginally to a significant extent. A high frequency of abscesses was recorded in the Klamath Basin and the Lower Columbia River sample, which also showed the highest levels of attrition. Each of the five subsamples shows patterns of dental pathology consistent with former use of natural resources.

Dentition↗
PubMed1984

A field comparison of seven diagnostic techniques for human trypanosomiasis in the Luangwa Valley, Zambia.

One serological and six parasitological techniques for diagnosing human trypanosomiasis were compared with regard to sensitivity, specificity, positive and negative predictive values, and practicality in field application in the Luangwa Valley of Zambia. Seven (0.64%) trypanosomiasis cases were diagnosed parasitologically in a survey of 1093 people from 19 villages. The indirect fluorescent antibody test (IFAT) was more sensitive but less specific than the parasitological techniques, detecting 71% of the confirmed cases in the first round of testing. Rat inoculation, the Giemsa stained thick film and miniature anion-exchange/centrifugation (mAEC) were all more sensitive than wet blood film examination, microhaematocrit centrifugation and wet film examination of the buffy coat after microhaematocrit centrifugation. The comparison indicated that the most effective, practical combination of techniques for survey in the Luangwa Valley was IFAT screening followed by examination of seropositive patients by rat inoculation and the mAEC (or stained thick film) in parallel format. Calculation of positive and negative predictive values showed that trypanosomiasis point prevalence measured in this way would still be underestimated by approximately 60%, indicating the need to improve IFAT specificity and parasitological sensitivity. Although only one of the seven patients diagnosed in the survey presented with signs and symptoms indicating possible trypanosomiasis, no evidence of a population of "healthy carriers" was found.

Adolescent↗
PubMed1983

Aspergillosis of the cerebral ventricles in a heroin abuser. Case report and review of the literature.

Aspergillosis of the cerebral ventricles developed in a 36-year-old heroin abuser who died during the sixth week of illness. The diagnosis was not made during life. A review of our case and of four previous cases from the literature indicates that aspergillosis should be considered in parenteral drug abusers with the syndrome of chronic meningitis or ventriculitis. The diagnosis is difficult to establish, but serologic tests may be helpful. This form of CNS aspergillosis can be cured with antifungal drugs.

Adult↗
PubMed1983

Apparent meningococcemia: clinical features of disease due to Haemophilus influenzae and Neisseria meningitidis.

To determine the etiology of apparent meningococcemia, all cases of sepsis with coagulopathy, purpura, and/or adrenal hemorrhage (Waterhouse-Friderichsen syndrome) with and without shock occurring over a 12-year period were reviewed. A total of 42 cases were identified; 30 cases were caused by Neisseria meningitidis and 12 cases were caused by Haemophilus influenzae. Compared with patients with disease caused by H influenzae, patients with meningococcal disease were older, more often male, more often contracted the disease in winter-spring, and had a longer duration of antecedent symptoms; however, none of these differences was statistically significant. All patients were febrile (greater than 38 degrees C) and appeared toxic. Similar proportions in each group had shock and disseminated intravascular coagulopathy at the time of admission. Ten of 12 patients with H influenzae infection compared with 15/30 (P less than .05) with meningococcal infection were lethargic or comatose at the time of admission. Nine of 12 patients with H influenzae infection died compared with 5/30 with meningococcal disease (P less than .005); the mean time from onset of symptoms to death with H influenzae infection (20.7 +/- 11.4 [SE] hours) was significantly shorter (P less than .05) than with meningococcal infection (120 +/- 74.4 hours). Children with clinical signs of sepsis and with purpura, petechiae, or coagulopathy may have N meningitidis or H influenzae as etiologic agents. Initial antibiotic therapy should be directed against these pathogens.

Age Factors↗
PubMedDate not supplied

Concepts and methods for assessing the quality of essential obstetric care.

Approaches to reducing maternal mortality and morbidity have attracted much attention in the last decade. It is recognized that availability and use of essential obstetric care (EOC) of sound quality by women in labor would reduce the burden of illness and death resulting from pregnancy. However, the literature on methods for defining, assessing and improving the quality of EOC at the point of service delivery in developing countries is quite weak. Drawing upon fundamental concepts of quality assurance, statistics, clinical practices and health service management, this article presents unifying concepts and methods for defining, assessing and improving the quality of EOC in developing country settings. It argues that any intervention that would improve the quality of EOC must act through at least one of three mechanisms: improve the clinical management of uncomplicated labor; improve the detection of complications of labor; or, improve the clinical management of complications of labor. The text presents the basis for using quantitative and qualitative methods to assess the quality of EOC. It concludes that any method to assess the quality of EOC, as a basis for improvement at the health center level, must satisfy the following seven criteria: (i) be derived from scientifically sound and locally defined guidelines for what constitutes care of good quality; (ii) enable objectively verifiable measurements of the performance of critical tasks; (iii) be sufficiently discriminating to detect variations in quality among health centers, thereby enabling managers to focus on improving care in those health centers providing care of lower quality; (iv) facilitate production of visual aids within each health center, thereby enabling midwives, doctors and their supervisors to use information for improving their work on a daily basis; (v) include qualitative assessments to facilitate interpretation of quantitative information; (vi) be reasonably simple to use without unsustainable foreign technical assistance; and, (vii) be affordable within the limited resources of public health facilities and District Health Management Teams.

Developing Countries↗
PubMedDate not supplied

Fetal urine production rates following intrauterine transfusion.

This study investigates the hypothesis that following an intrauterine, intravascular transfusion (IVT), one of the physiologic adaptations might be an increase in the fetal urine production. The hourly fetal urine production rate (HFUPR) was measured for the first hour following 12 transfusions and for 24 h following 5 transfusions in anemic isoimmunized fetuses. The HFUPR was also measured in 5 control fetuses who underwent fetal blood sampling without transfusion. Fetal hemoglobin, hematocrit and blood viscosity were measured before and after each transfusion. The HFUPR fell significantly from a mean (SEM) of 19.2 (2.85) to 7.4 (2.2) ml/h, and remained low for at least 4 h posttransfusion returning to pretransfusion rates by 24 h. There was no change in the HFUPR in the control fetuses. The study suggests that in human fetuses the rapid excretion of excess fluid via the renal tract is not an acute adaptive response to an IVT.

Adaptation, Physiological↗
PubMedDate not supplied

Methotrexate pulse therapy in the treatment of recurrent acute heart rejection.

Despite cytolytic induction therapy and triple-drug immunosuppression, acute allograft rejection continues to cause important morbidity and occasional death after heart transplantation. Between November 1, 1988, and May 1, 1990, 24 patients received methotrexate pulse therapy for recurrent or persistent acute rejection despite methylprednisolone, OKT3, or antithymocyte globulin therapy. Methotrexate was administered as a daily oral dose of 2.5 to 15 mg on 1 day/week over 3 weeks (longer in 15 patients because of either severe leukopenia with temporary interruption of therapy or recurrent rejection during methotrexate therapy) with reduction or discontinuation of azathioprine. Rejection incidence was reduced from 1.1 episodes/patient month before methotrexate therapy to 0.2 episodes/patient month after completion of therapy (p = 0.0001). Two patients died within 3 months after treatment, one of cytomegalovirus pneumonia and one of lymphoma. Mean white blood count (WBC) fell from 6900 per ml before methotrexate therapy to 3700 during the first month of methotrexate therapy (p = 0.0005). The lowest WBC typically occurred about 3 weeks after starting methotrexate therapy, and a transient WBC of less than 1000/ml developed in seven patients. By multivariable analysis, the WBC 1 month after starting methotrexate therapy was significantly related to greater bone marrow suppression (lower WBC), immediately before methotrexate therapy, greater overall immunosuppression (more rejection episodes) during the 3 months before methotrexate therapy, and a higher total dose of methotrexate. The following conclusions can be drawn: (1) Methotrexate is a useful adjunct in the treatment of recurrent or persistent rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗