Biomedical subjects

J Kalbfleisch

Publications and source records attributed to J Kalbfleisch.

29 records · Page 2Linked to original sources

PubMed1989

Principles in injury control: lessons to be learned from child safety seats.

The effort to increase the use of child safety seats (CSS) over the last decade has been an outstanding success in the field of childhood injury control. This article describes that effort and discusses lessons which can be learned and applied to other injury control problems. These include choosing a specific important problem and addressing it with a particular solution, developing a critical mass of community awareness through broad-based grass roots support, legislation, efforts of primary care physicians, and eventual institutionalization of the program.

Child↗

PubMed1987

Detection of exercise induced changes in left ventricular performance by Doppler echocardiography.

A study was performed to test the hypothesis that Doppler echocardiographic measurement of ascending aortic blood flow can detect exercise induced changes in left ventricular performance during exercise in patients suspected of having ischaemic heart disease. Acceleration and peak velocity of flow and stroke volume were determined by non-imaging Doppler echocardiography in the suprasternal notch in 38 patients as they underwent simultaneous exercise radionuclide ventriculography. The patients were divided into four groups: group 1 had resting ejection fractions greater than or equal to 50% and increased their ejection fractions greater than or equal to 5% during exercise; group 2 had resting ejection fractions of greater than or equal to 50% but the ejection fraction either fell or rose less than 5% during exercise; group 3 had resting ejection fractions less than 50% but the ejection fraction rose greater than or equal to 5% during exercise; and group 4 had resting ejection fractions less than 50% and the exercise ejection fraction either fell or rose less than 5% during exercise. Acceleration, velocity, and stroke volume all rose significantly during exercise in group 1. Acceleration also increased in group 2 but to a lesser extent; velocity and stroke volume did not increase. In group 3 acceleration and velocity increased but to a lesser extent than in group 1; stroke volume did not increase. In group 4 velocity increased slightly during exercise but acceleration and stroke volume were unchanged. Doppler echocardiography thus appears capable of detecting exercise induced changes in left ventricular performance and can identify normal and abnormal responses, as defined by radionuclide ventriculography.

Adult↗

PubMed1986

The influence of preload and heart rate on Doppler echocardiographic indexes of left ventricular performance: comparison with invasive indexes in an experimental preparation.

We evaluated the ability of Doppler echocardiography to assess left ventricular performance in six open-chest dogs studied under various conditions. Intravenous infusions of nitroglycerin were used to vary preload, atrial pacing was used to control heart rate, and changes in inotropic state were induced by two different doses of dobutamine (5 and 10 micrograms/kg/min iv) and by administration of propranolol (1 mg/kg iv). Left ventricular anterior wall myocardial segment length was used as an index of preload. Maximum aortic blood flow, peak acceleration of aortic blood flow, and dP/dt were measured with an electromagnetic flow probe around the ascending aorta and a high-fidelity pressure transducer in the left ventricle. A continuous-wave Doppler transducer applied to the aortic arch was used to measure peak aortic blood velocity, mean acceleration, time to peak velocity, and the systolic velocity integral. The differences between mean values obtained under different inotropic conditions were significant at the p less than .01 level for peak velocity and at the p less than .05 level for mean acceleration. Within a given animal, Doppler measurements of peak velocity correlated very closely with maximum aortic flow (r = .96), maximum acceleration of aortic flow (r = .95), and with maximum dP/dt (r = .92). Mean acceleration measured by Doppler echocardiography also correlated very closely with conventional indexes, but was subject to greater interobserver variability. Doppler measurements of time to peak and the systolic velocity integral correlated less well with conventional hemodynamic indexes.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1984

The influence of myelosuppression on the response to chemotherapy in small cell bronchogenic carcinoma.

In an attempt to clarify the relationship between myelosuppression and the response to chemotherapy, 127 cases of small cell lung cancer were reviewed. These patients received a total of four different drug combinations. The myelosuppression of the first chemotherapy course was reduced with the addition of one or two drugs to the basic Cytoxan (cyclophosphamide)-vincristine drug combination without a change in the incidence of remission. Patients with good performance status have less severe leukopenia and thrombocytopenia than those with poor performance status. Patients with complete and partial response have slightly more severe thrombocytopenia but not leukopenia than the nonresponders. It is concluded that the burden of tumor has a direct effect on the incidence of remission and myelosuppression suggesting that more severe toxicity is necessary to obtain remission in poor risk patients. Myelosuppression is required before assessing whether the patient has received an adequate amount of chemotherapeutic agent but is only a weak prognostic factor.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1984

Recovery of in vivo cellular immunity after human marrow grafting. Influence of time postgrafting and acute graft-versus-host disease.

Three hundred thirty-two marrow graft recipients and 241 healthy marrow donors were studied by skin testing with recall and neoantigens. Two hundred thirty patients with leukemia and seventy-eight patients with aplastic anemia received allogeneic HLA-identical sibling marrow. Twenty-four patients with leukemia received syngeneic marrow. The conditioning regimen prior to marrow infusion consisted of 120 mg/kg cyclophosphamide and 9.2-15.75 Gy total-body irradiation (leukemia) or 200 mg/kg cyclophosphamide (aplastic anemia). The patients were skin-tested with the neoantigens dinitrochlorobenzene (DNCB), keyhole limpet hemocyanin, and a battery of five recall antigens around 100, 150, 365, 730, 1095, 1460, and 1825 days after grafting. A binary logistic regression analysis was used to investigate the factors thought to influence immunocompetence. At 3 months postgrafting, the proportion of patients positive to DNCB was equal to that of normal marrow donors, but thereafter it was lower until 2 years. The proportion of patients positive to keyhole limpet hemocyanin was lower than normal regardless of the time after grafting. The proportion of patients positive to recall antigens was lower than that of normal marrow donors until 4 years after grafting. Patients with a history of acute graft-versus-host disease had the lowest probability of a positive reaction to recall antigens. None of the other factors was significantly associated with an increased or reduced level of response.

Acute Disease↗

PubMed1984

Upper airway morphology in patients with idiopathic obstructive sleep apnea.

Fundamental to the pathogenesis of obstructive sleep apnea (OSA) is the interaction of physiologic and anatomic alterations of the upper airway. However, many patients with OSA have no identifiable abnormality of the upper airway, and they have been termed idiopathic. In an attempt to find a structural deviation in upper airway anatomy, we performed acoustic echography and cephalometric roentgenograms in 9 male patients with OSA and no clinical evidence of upper airway abnormality. Mean cross-sectional area of the pharynx by acoustic reflection was less in these patients (3.7 +/- 0.8 cm2) than in subjects in a control group (5.3 +/- 0.6 cm2) (p less than 0.001). Mean glottic cross-sectional area was less in the patient group (1.5 +/- 0.5 cm2) than in the control group (2.7 +/- 0.5) (p less than 0.001). There was a significant correlation between the number of apneas per sleep hour and pharyngeal cross-sectional area (r = 0.87, p less than 0.01). Cephalometric analysis indicated that the patients had smaller mandibles by a mean of 5.4 +/- 6.6 mm (p less than 0.05). The overall posterior displacement of the mandibular symphysis, which is representative of the skeletal support of the anterior pharyngeal wall and is dependent on both mandibular size and position, was highly significant (6.4 +/- 4.7 mm) (p less than 0.01). Furthermore, there was a significant correlation between the number of apnea episodes per sleep hour and the total posterior displacement (r = 0.67, p less than 0.05). This study indicates that patients with so-called idiopathic OSA may have an anatomic predisposition to the development of upper airway occlusion that may not be detectable on clinical examination.

Adult↗

PubMed1981

Combined H1 and H2 antihistamine therapy in chronic urticaria.

Chronic urticaria is a frustrating problem for the patient and the physician. The cause is usually undetermined, and the therapy is directed toward controlling symptoms. Recent evidence that human skin blood vessels possess H2 receptors, as well as the commonly recognized H1 receptors, suggests a possible reason for the frequent failure of H1 antihistamines in controlling this disorder. Eighteen patients with refractory chronic idiopathic urticaria participated in a double-blind, cross-over study to evaluate the efficacy of combined H1 (hydroxyzine hydrochloride) and H2 (cimetidine) antihistamines vs H1 antihistamines alone. This study indicates that combined H1 and H2 antihistamine therapy is statistically more effective than H1 antihistamines alone in controlling the symptoms of chronic urticaria.

Adult↗

PubMed1980

Stability of renal transplant function with alternate-day corticosteroid therapy.

Fifty-three renal transplant recipients with good to excellent renal function, while receiving daily maintenance or near-maintenance doses of azathioprine and methylprednisolone, were gradually converted to alternate-day corticosteroid therapy. Stability of allograft glomerular filtration rate (GFR) in each patient was assessed by calculating the slope of a plot of the reciprocal of the serum creatinine concentration vs time. After conversion to alternate-day therapy, GFR was stable in 80% but deteriorated in 20% of patients. However, most of the patients who experienced deteriorating GFR during alternate-day therapy regained stable renal function when given the same total corticosteroid dose but on a daily basis. This suggests but does not prove that maintenance-level daily corticosteroid therapy is better than maintenance-level alternate-day therapy in stabilizing allograft function. We conclude that maintenance-level alternate-day corticosteroid therapy should be used cautiously until a long-term prospective study determines whether there is an increased risk of losing renal function with this schedule and whether this potential risk is offset by reduced corticosteroid toxicity.

Adrenal Cortex Hormones↗

PubMedDate not supplied

Comparison of peak and modal aortic blood flow velocities with invasive measures of left ventricular performance.

The purpose of this study was to determine the accuracy of Doppler-derived modal and maximum velocity and peak and mean acceleration of ascending aortic blood for the assessment of left ventricular systolic function. Studies were performed in six anesthetized open-chest dogs. Doppler-derived modal velocity, maximum velocity, and peak and mean acceleration were compared with left ventricular dP/dt, maximum aortic blood flow, and rate of blood flow measured with an electromagnetic flow probe under varying inotropic states. Maximum Doppler velocity showed better correlation (r = 0.94, y = 0.34 + 3.95) with maximum aortic blood flow than the modal velocity (r = 0.85, y = 1.49 + 3.85x). Peak acceleration also correlated better with the rate of blood flow (r = 0.92, y = 12.3 + 4.92x) than the mean acceleration (r = 0.83, y = 12.2 + 4.27x). Modal and maximum velocity and mean and peak acceleration correlated well with left ventricular dP/dt. We conclude that peak modal and peak maximum velocity and peak and mean acceleration are accurate measurements of left ventricular function. Maximum velocity and peak acceleration are more accurate than modal velocity and mean acceleration.

Animals↗

PubMedDate not supplied

The effect of changes in afterload on Doppler echocardiographic indexes of left ventricular performance.

To investigate the influence of changes in afterload on Doppler echocardiographic determination of peak aortic blood velocity, mean acceleration, and systolic velocity integral, eight dogs with their chests opened were studied in four inotropic states at varying levels of heart rate and mean aortic blood pressure. Data were collected in the control state, at two different levels of dobutamine administration (5 and 10 micrograms/kg/min intravenously), and after administration of propranolol (0.5 mg/kg intravenously). In each inotropic state, phenylephrine was infused intravenously to produce at least two successive steady state increases of 10 mm Hg or more in mean aortic blood pressure. Within a given animal, peak velocity emerged as the Doppler index most closely correlated with changes in Qmax, dQ/dt, and dP/dt (r = 0.94, 0.91, and 0.89, respectively). Mean acceleration also correlated closely with the invasive indexes (r = 0.87, 0.89, and 0.89). The effect of changes in mean aortic blood pressure on Doppler index measurements was not statistically significant in any of the inotropic states and did not affect the closeness of their correlation with the invasive indexes. We conclude that Doppler echocardiographic measurements of aortic blood peak velocity and mean acceleration remained as sensitive to changes in the inotropic state under conditions of varying increases in afterload as did the conventional invasive indexes tested.

Animals↗

PubMedDate not supplied

Alcohol: high density lipoproteins, apolipoproteins.

Plasma lipids, including high density lipoproteins (HDL) components, were studied in 26 healthy male alcohol abusers. Age- and gender-matched controls denied the use of substances or behaviors associated with increased HDL. On admission to abstinence treatment, the alcohol abusers' total cholesterol and triglycerides were usually normal. Their HDL-cholesterol levels were high, and fell to normal within 2 weeks of sobriety. Apolipoprotein (APO) AI and AII were high initially and also became normal in 2 weeks. APO A I and II to HDL-cholesterol ratios appeared to change during abstinence, while APO AI/AII did not. APO CIII, high initially, fell during treatment, but was still high after 4 weeks of sobriety. Therefore, alcohol seems to affect several components of HDL and these HDL changes move toward normal at different rates. If alcohol is protective against some cardiovascular disease, it remains to be established whether HDL is involved and which HDL component is most important.

Adult↗