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Biomedical subjects

C Cox

Publications and source records attributed to C Cox.

At least 289 records · Page 16Linked to original sources
PubMed1994

A comparison of thrombolytic therapy with operative revascularization in the initial treatment of acute peripheral arterial ischemia.

PURPOSE: Despite the widespread use of intraarterial thrombolytic therapy for peripheral arterial occlusive disease, a randomized study comparing its efficacy with that of operative intervention has never been performed. This study evaluates the potential of intraarterial urokinase infusion to provide clinical benefits in patients with acute peripheral arterial occlusion. METHODS: Patients with limb-threatening ischemia of less than 7 days' duration were randomly assigned to intraarterial catheter-directed urokinase therapy or operative intervention. Anatomic lesions unmasked by thrombolysis were treated with balloon dilation or operation. The primary end points of the study were limb salvage and survival. RESULTS: A total of 57 patients were randomized to the thrombolytic therapy group, and 57 patients were randomized to the operative therapy group. Thrombolytic therapy resulted in dissolution of the occluding thrombus in 40 (70%) patients. Although the cumulative limb salvage rate was similar in the two treatment groups (82% at 12 months), the cumulative survival rate was significantly improved in patients randomized to the thrombolysis group (84% vs 58% at 12 months, p = 0.01). The mortality differences seemed to be primarily attributable to an increased frequency of in-hospital cardiopulmonary complications in the operative treatment group (49% vs 16%, p = 0.001). The benefits of thrombolysis were achieved without significant differences in the duration of hospitalization (median 11 days) and with only modest increases in hospital cost in the thrombolytic treatment arm (median $15,672 vs $12,253, p = 0.02). CONCLUSIONS: Intraarterial thrombolytic therapy was associated with a reduction in the incidence of in-hospital cardiopulmonary complications and a corresponding increase in patient survival rates. These benefits were achieved without an appreciable increase in the duration of hospitalization and with only modest increases in hospital cost, suggesting that thrombolytic therapy may offer a safe and effective alternative to operation in the initial treatment of patients diagnosed with acute limb-threatening peripheral arterial occlusion.

Acute Disease↗
PubMed1994

Association of in utero behavioral patterns of twins with each other as indicated by fetal heart rate reactivity and nonreactivity.

Prospective analysis of 75 pairs of nonstress tests (NSTs) obtained simultaneously from both members of 35 twin gestations was performed to quantitatively assess the incidence of simultaneous periods of fetal heart rate (FHR) reactivity and nonreactivity of twins. Comparative analysis of the paired NSTs was used to compute rates of simultaneous fetal heart rate reactivity and nonreactivity. Statistical analysis involved comparison of weighted averages of these rates, using sequence lengths as weights. Weighted standard deviations were used to describe variability between sets of NSTs. Trend analysis was performed using weighted linear regression to calculate slopes for pairs of twins with three or more repeat NSTs. Groups of twins were compared by performing a variance stabilizing transformation on the appropriate rates, and using a two sample t test to compare the means of transformed data. Analysis of this data revealed that twins exhibited similar in utero fetal heart reactivity and nonreactivity as indicated by simultaneous electronic fetal monitoring during 79.90% +/- 1.62 (SD) of the time monitored. The incidence of periods of simultaneously reactive FHR and simultaneously nonreactive FHR were 11.79% +/- 1.02 and 68.10% +/- 2.17, respectively, irrespective of gestational age. These data confirm the hypothesis that periods of FHR reactivity and nonreactivity of twins are strongly associated with each other.

Female↗
PubMed1994

Factors affecting the outcomes of hospitalized dementia patients: from home to hospital to discharge.

This study examined factors associated with willingness to continue in the caregiving role after the hospitalization of a relative with dementia. Interviews were conducted with 179 caregivers of hospitalized patients to determine the influences of predisposing, enabling, and need factors in the discharge decision. Logistic regression was used to identify variables predictive of caregivers taking patients home for those who were originally planning on doing so and for those who were originally undecided. For the first group, only a prolonged hospital stay significantly influenced the discharge disposition. The undecided caregivers were likely to seek placement for patients with more severe cognitive impairment, although having formal assistance with specific tasks increased the probability of a discharge home.

Aged↗
PubMed1994

A test of the influence of cyclotron resonance exposures on diatom motility.

An attempt was made to test the hypothesis (McLeod et al. 1987; Smith et al. 1987) that a certain combination of direct current and alternating current magnetic field exposures at room temperature results in an increase in motility of a marine diatom (Amphora coffeaeformis) to a maximum value. Diatom motility increased as a function of calcium concentration in the medium, as reported by McLeod et al. (1987) and Smith et al. (1987). There was, however, no effect of the magnetic field exposures on diatom motility. The exposures employed 16-Hz magnetic fields with amplitudes of 21 or 29.7 microT (21 microT rms) as well as 21 microT (amplitude) fields at frequencies above and below the reported "resonance" frequency. All experiments were conducted double blindly, and each trial had its own positive control.

Calcium↗
PubMed1994

Minimally differentiated acute myeloid leukaemia (AML-M0): cytochemical, immunophenotypic and cytogenetic analysis of 19 cases.

We describe our experience in the identification of 19 cases of AML-M0 categorized among 200 consecutive AML cases. Leukaemic cells from our cases were morphologically marked by agranular basophilic cytoplasm, finely dispersed chromatin and prominent nucleoli. In two cases heavily vacuolated and monocytoid-shaped blasts were also observed. Cytochemistry (MPO, SBB, alpha ANAE, alpha NBE, NASDCAE, AP, PAS) was negative in 14 cases, five cases expressing a very faint cytoplasmic positivity for alpha NBE (not exceeding 30% of the blasts) and alpha ANAE (not exceeding 41%) which was sodium fluoride resistant. In these five cases other monocytic markers (e.g. CD14) were not in favour of myelomonocytic differentiation. All the cases were anti-MPO positive at frequency > 10%. Phenotypic analysis also revealed myeloid features with all the patients having at least one myeloid antigen (CD13, CD33, CD15), Tdt was expressed in nine cases and CD7 in six cases. All cases but one were positive for CD34. Cytogenetic analysis, performed in 16 cases, showed no adequate growth in two cases and no consistent abnormality in four; among the remaining 10 cases no consistent abnormality was observed, the most common finding was trisomy 8 (two cases) and 4 (two cases) and aberrations of chromosomes 2, 3, 5, 7, 9, 12 and 21. No cases of (t9;22), Ph chromosome were observed. Interestingly three out of five patients with faint alpha NBE/alpha ANAE positivity relapsed as typical M4 (one case) or M5a (two cases).

Acute Disease↗
PubMed1994

The chronic myeloid leukaemias: guidelines for distinguishing chronic granulocytic, atypical chronic myeloid, and chronic myelomonocytic leukaemia. Proposals by the French-American-British Cooperative Leukaemia Group.

We have reviewed our experience with four of the entities that are included under the generic term chronic myeloid leukaemia (CML), namely the classic Ph+ CGL, both BCR+ and BCR-, aCML and CMML. We have developed a statistical model that confirms that CGL, aCML and CMML can be distinguished from each other with reasonable success employing five quantitative parameters (WBC, percentage immature granulocytes, percentage monocytes, percentage basophils, percentage erythroid precursors in bone marrow) and one qualitative parameter (granulocytic dysplasia). It is hoped that these detailed recommendations will enable investigators to improve their diagnostic accuracy. This should permit more uniform comparisons of molecular biologic and clinical studies.

Bone Marrow↗
PubMed1994

Carbamazepine treatment of agitation in nursing home patients with dementia: a preliminary study.

OBJECTIVE: To determine the effects of carbamazepine versus placebo on ratings of behavior in agitated nursing home patients with dementia. DESIGN: Nonrandomized, placebo-controlled, crossover trial conducted in 25 patients in two nursing homes. INTERVENTION: Carbamazepine and placebo were administered during two 5-week periods separated by a 2-week washout. The carbamazepine dose was determined for each patient by a nonblinded physician who did not participate in ratings (modal dose 300 mg/day). MEASUREMENTS: The primary outcome measures were Brief Psychiatric Rating Scale scores and Clinical Global Impression of Change, rated by blind observers. Secondary measures of behavior, adversity, cognition, and functional status were also included. MAIN RESULTS: Median total Brief Psychiatric Rating Scale score decreased 7 points on carbamazepine versus 3 on placebo (P = 0.03). Sixteen subjects were rated as improved globally on carbamazepine versus four on placebo (P = 0.001). Secondary measures of behavior showed similar changes at significant or suggestive (P < 0.10) levels. One subject developed carbamazepine-induced tics, and one died with a pneumonia. There was minimal other adversity. CONCLUSION: This preliminary study suggests that carbamazepine in low doses can reduce agitated behaviors in some patients, with limited adversity resulting. Further research is required to confirm and extend this finding before it can be considered routine clinical practice.

Aged↗
PubMed1994

Two doses of early intravenous dexamethasone for the prevention of bronchopulmonary dysplasia in babies with respiratory distress syndrome.

Bronchopulmonary dysplasia is an important complication of ventilation in babies for which treatment with steroids has been advocated. We report the results of a phase I study of early i.v. dexamethasone to prevent the development of bronchopulmonary dysplasia in a high-risk population of ventilated premature babies, < 30 wk gestation, with surfactant-treated respiratory distress syndrome. This study used a limited dexamethasone dosing regimen to minimize toxicity but used administration early in the course of acute lung disease to interrupt the injury cycle. Forty babies were enrolled; 19 were randomized to receive dexamethasone (0.5 mg/kg birth weight at 12-18 h of age and a second dose 12 h later) and 21 were randomized to receive placebo (i.v. saline). The dexamethasone group required less ventilatory support (mean airway, peak inspiratory and end expiratory pressures, and intermittent mandatory ventilation) and supplemental oxygen after study d 4 (all p < 0.05, repeated measures analysis of variance). Improved tidal volume in the dexamethasone group, as measured by pulmonary function testing of infants who remained intubated, was seen on study d 7 (p = 0.02, t test). The dexamethasone group required shorter hospitalizations (median of 95 d versus 106 d, p = 0.01) (proportional hazards regression). Survival in the dexamethasone group was 89% versus 67% in the placebo group (p = 0.08, chi 2 analysis). Survival without bronchopulmonary dysplasia, diagnosed at 36 wk corrected gestational age, was 68% in the dexamethasone group versus 43% in the placebo group (p = 0.14).(ABSTRACT TRUNCATED AT 250 WORDS)

Bronchopulmonary Dysplasia↗
PubMed1994

Heart rate power spectrum and plasma catecholamine levels after postural change and cold pressor test.

During stress, low-frequency (0.01-0.15 Hz) heart rate power and plasma catecholamine levels increase in response to increased sympathetic efferent activity. To test the hypothesis that low-frequency heart rate power, a measure of sympathetic control of heart rate, directly correlates with plasma catecholamine concentrations during periods of increased sympathetic tone, we compared heart rate power spectral measures with antecubital vein norepinephrine, epinephrine, and dopamine concentrations during postural change and after cold pressor testing. We analyzed absolute levels and changes in mean heart rate, respiratory rate, blood pressure, heart rate power spectra, and concentration of norepinephrine, epinephrine, and dopamine in 14 healthy volunteers (seven female/seven male) after postural change and in six (three female/three male) during cold pressor testing. Postural change from supine to standing position resulted in increased heart rate [61 +/- 8 versus 83 +/- 11 (SD) bpm, p < 0.05], diastolic (68 +/- 7 versus 77 +/- 6 mm Hg, p < 0.05) and mean blood pressures (84 +/- 6 versus 91 +/- 9 mm Hg, p < 0.05), norepinephrine concentration (2.09 +/- 1.11 versus 3.23 +/- 1.62 nmol/L, p < 0.05), and low-frequency heart rate power (7.55 +/- 5.63 versus 33.79 +/- 23.55 bpm2, p < 0.05). High-frequency heart rate power, a measure of parasympathetic control of heart rate, decreased with standing (5.38 +/- 4.22 versus 2.94 +/- 2.69 bpm2, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Neonatal endotracheal tubes: variation in airway resistance with different perfluorochemical liquids.

To evaluate the effect of the physical properties of density and viscosity on airway resistance, three perfluorochemical fluids (PFCs) were used: FC-75, Liquivent, and APF-140. Using two different endotracheal tubes (ETT) (3.0mm ID and 4.0mm internal diameter (ID)), the three fluids were studied at steady state flow conditions over a range that approximated peak flow required for liquid ventilation of neonatal lambs (0.005-0.02 l/sec). The slope of airway resistance (Raw)-flow curves and absolute values of Raw for the 3 PFC liquids were higher for the 3.0 ETT compared to the 4.0 ETT. The 3.0 ETT demonstrated resistance changes that were dependent on flow, density and viscosity. The 4.0 ETT showed a resistance-flow relationship that was relatively less dependent on flow, density and viscosity.

Airway Resistance↗
PubMed1994

Oxidant and acid aerosol exposure in healthy subjects and subjects with asthma. Part II: Effects of sequential sulfuric acid and ozone exposures on the pulmonary function of healthy subjects and subjects with asthma.

These studies were undertaken to evaluate pulmonary responses of humans sequentially exposed to acidic aerosols and ozone at levels that could reasonably be encountered in actual environmental exposures. Subjects first were exposed to sulfuric acid (H2SO4) aerosol to sensitize the airways to ozone. The exposure protocols were designed to provide more quantitative information about the threshold levels of ozone that produce adverse biological effects and to provide exposure-response data on ozone. Two groups of 30 nonsmoking volunteers of both sexes, between the ages of 18 and 45 years, were recruited. The healthy study population comprised 16 men and 14 women with an average age of 28 years and no airway hyperreactivity. The second group comprised 10 men and 20 women comparable in age to the control group, but with allergic asthma and positive skin tests. The study examined an exposure-response relationship using three levels of ozone ranging from below the current standard to one and one-half times the ambient air quality standard (0.08, 0.12, and 0.18 ppm* [parts per million]) with preexposure 24 hours earlier to H2SO4 (100 micrograms/m3) or sodium chloride (NaCl) (control) aerosol in a 45-m3 environmental chamber. The study used an incomplete block design in which each subject was exposed to four of the six paired experimental atmospheres. Both the selection of paired exposures and the order in which they were presented were randomized. The exposure protocol required nine days: Day 1, training and baseline preexposure measurements; Day 2, the first of the three-hour particle (H2SO4 or NaCl) exposures; Day 3 (24 hours after Day 2), ozone exposure at 0.08, 0.12, or 0.18 ppm for three hours; Day 4 (two to four weeks later), exposure to the same ozone concentration as on Day 4. After at least another two weeks, Days 6, 7, 8, and 9 repeated Days 2, 3, 4, and 5 using a second ozone concentration. All three-hour exposures included several predetermined periods of exercise and pulmonary function measurements. To examine for delayed effects, pulmonary function tests were measured two and four hours after exposure on the ozone days. Data were analyzed over the time course of exposure and by exposure level of ozone at each time point to reveal dose-response relationships more closely. The main findings of the study are as follows. No significant symptomatic or physiologic effects of exposure to either aerosol or ozone on lung function were found for the healthy group.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1993

Ectopic neural expression of a floor plate marker in frog embryos injected with the midline transcription factor Pintallavis.

The floor plate, a cell group that develops at the midline of the neural plate in response to inductive signals from the notochord, has been implicated in the control of dorsoventral neural pattern. The frog Pintallavis gene, encoding a member of the HNF-3/fork head transcription factor family, is expressed in the notochord and in midline neural plate cells that give rise to the floor plate. To examine whether Pintallavis might be involved in regulating the differentiation of the floor plate, we ectopically expressed Pintallavis by injection of synthetic mRNA into two-cell frog embryos. Injection of Pintallavis mRNA resulted in the ectopic expression of F-spondin, a gene encoding a floor plate-specific adhesion molecule, at the dorsal midline of the neural tube. The expression of Pintallavis in midline cells may therefore contribute to the establishment of the floor plate fate.

Albinism↗
PubMed1993

End-stage Alzheimer's disease. Glasgow Coma Scale and the neurologic examination.

OBJECTIVE: To characterize the cognitive and neurologic features of patients with end-stage Alzheimer's disease using a standard neurologic examination and the Glasgow Coma Scale. DESIGN: Case series. SETTING: Local community nursing homes. PATIENTS: Forty patients with Alzheimer's disease were drawn from previously enrolled subjects in the Rochester Alzheimer's Disease Project with Clinical Dementia Rating scores of 3, 4, or 5. MAIN OUTCOME MEASURES: Scores on the Glasgow Coma Scale and cognitive screening examinations and the prevalence of neurologic manifestations such as primitive reflexes and extrapyramidal signs were compared across the Clinical Dementia Rating groups. RESULTS: When compared with patients in the Clinical Dementia Rating stages 3 and 4, patients with a stage 5 scored significantly lower on the Glasgow Coma Scale, with the discriminating subscales being verbal and motor responses. Primitive reflexes, myoclonus, and dyskinesia were increasingly prevalent in the more terminal stages. Cognitive screening assessments did not discriminate between groups. CONCLUSIONS: Rudimentary neurologic functions can be readily assessed and, when viewed together with the Glasgow Coma Scale, may circumvent the "floor effect" frequently encountered when using the currently available cognitive and functional scales and, thereby, better define patients with end-stage Alzheimer's disease.

Aged↗
PubMed1993

Localization of insulin-like growth factor-I-like immunoreactivity in the reproductive tract of the vitellogenic female American alligator, Alligator mississippiensis.

Insulin-like growth factor I (IGF-I) is a 70 amino acid, mitogenic polypeptide, which, in mammals, acts through an endocrine, paracrine, and/or autocrine pathway to regulate growth and development. The primary goal of this study was to determine whether or not IGF-I-like immunoreactivity is present in the oviduct of the vitellogenic American alligator, Alligator mississippiensis, and if immunoreactivity patterns vary among the three functional oviducal regions: the albumen-secreting tube region, the anterior, fiber-secreting uterus, and the posterior, calcium-secreting uterus. Immunolocalization of IGF-I-like immunoreactivity was accomplished using a polyclonal antihuman rabbit antiserum with an immunoperoxidase staining system. IGF-I-like immunoreactivity was detected in all three oviducal regions of the vitellogenic alligator. The presence of IGF-I-like immunoreactivity in the oviduct suggests this hormone could function in the growth and proliferation of the alligator oviduct. Furthermore, the presence of IGF-I-like immunoreactivity in the tubal glands, which secrete components of the egg white, suggests that growth factors such as IGF-I may be synthesized by these glands and incorporated into the albumen during egg formation.

Alligators and Crocodiles↗