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Biomedical subjects

H Leopold

Publications and source records attributed to H Leopold.

At least 19 recordsLinked to original sources
PubMed2001

Hypoplastic left heart syndrome: factors influencing therapeutic choice.

Parent's choices among therapeutic options for their infants born with hypoplastic left heart syndrome are difficult and controversial. Currently, management options include surgical reconstruction, cardiac transplantation, and comfort measures only. We retrospectively reviewed medical records of 47 patients (1989-1999) to create a database of clinical features of infants who received either an operation or comfort care only. Eleven families were interviewed by means of a structured questionnaire pertaining to their experience and reasons for their choice. Of the 47, 20 were prenatally diagnosed and nine of these (45%) aborted. The remaining 38 of the 47 were liveborns. Of the 38, 20/38 (53%) chose comfort care only. The other 18 chose operation. Although 17 were able to survive until first stage repair, only 8/17 (47%) survived beyond five months. At the time of last contact (ages one to 4.5 years), 5/17 (29%) remained alive. Over the nine years an increasing proportion of parents chose operative reconstruction; 8/11 (73%) for 1996-99 vs 10/27 (37%) for 1989-1995. Interviewed families who chose comfort care were more likely to believe the rate of survival following operation was poor, quality of life was diminished, and seemed concerned that their infant would suffer. Influence by optimistic physicians at surgical centers seemed important for an operative choice. Most suggested that provision of written materials, professional family counseling, and support groups of hypoplastic left heart syndrome families are or would be helpful.

Abortion, Induced↗
PubMed1996

Evolution of cardiac rhabdomyoma in tuberous sclerosis complex.

The objective of the study was to define the longitudinal evolution of cardiac rhabdomyomas (CR) in patients with tuberous sclerosis complex (TSC). A cohort of patients with TSC who had undergone videotaped echocardiographic (ECHO) examination during the 10-year interval (1984-1994) were retrospectively studied by reviewing and quantifying the CR appearance and associated cardiac abnormalities in sequentially obtained ECHO examinations. Sixteen patients with TSC (8 males) underwent a total of 35 recorded studies. Ten of the 16 (62.5%) had CR identified at initial study; none were found in the atria. Localization was the ventricular walls as compared with the ventricular septum by a ratio of 2:1. The number of CRs sequentially studied declined as follows; initial study: 23 lesions in 10 patients; second study: 16 lesions in 8 patients; third study: 12 lesions in 5 patients; and fourth study: 4 lesions in 2 patients. Total CR size index declined at each study as follows: initial index of 2,684; second index of 1,746 (-35% from initial); third index 1,141 (-57% from initial); and fourth index 705 (-74% from initial). Complete spontaneous regression of CR was seen by age 6 years with prolonged gradual resolution thereafter. Two patients had bicuspid aortic valves and two had conduction defects. Patients with TSC who have CR can be expected to experience a decline in both the number and size of CR over time; early complete regression on ECHO occurs before age 6 years.

Adolescent↗
PubMed1981

Lymphoplasmacytic/lymphoplasmacytoid lymphoma: a clinical entity distinct from chronic lymphocytic leukaemia?

Clinical data of 116 patients with chronic lymphocytic leukaemia (CLL) and of 114 patients with lymphoplasmacytic/lymphoplasmacytoid lymphoma (synonym: LP immunocytoma, IC) as diagnosed according to the Kiel classification were compared. This interim evaluation of a prospective multicenter study of the Kiel Lymphoma Study Group characterizes IC the less favorable lymphoma entity as evidenced by a more rapid lymph node enlargement, by a higher incidence of constitutional symptoms and of marked anaemia, and by a higher percentage of patients requiring early treatment. In addition, in IC autoimmune haemolytic anaemia was detected in 11.2% of investigated patients as compared to none of the patients with CLL, and monoclonal gammopathy was disclosed in 34.2% of investigated patients as compared to only three patients with CLL who could be, however, unrecognized cases of IC. Actuarial survival data after a follow-up period of 40 months are in favor of an overall better prognosis of patients with CLL than of patients with IC.

Adult↗
PubMed1981

Germinal center cell lymphomas: prognostic significance of their histopathological differentiation.

Clinical data of 48 patients with centrocytic, 83 patients with centroblastic/centrocytic and 64 patients with centroblastic lymphoma who had entered a prospective multicenter study of the Kiel Lymphoma Study Group since October 1975 were compared. Advanced (stage IV) disease at time of diagnosis, predominantly due to bone marrow infiltration, was most frequent in centrocytic (69% of patients) and in centroblastic/centrocytic (51% of patients) lymphomas as compared to only 28% of patients with centroblastic lymphoma. High survival probability of patients with localized centrocytic and centroblastic/centrocytic lymphomas after radiotherapy, contrasting with a worse prognosis of corresponding patients with centroblastic lymphoma, is compatible with the classification of these lymphoma entities as neoplasias of low-grade malignancy. However, as shown by this prospective and previous retrospective trials overall survival probability of patients with advanced centrocytic lymphoma was inferior to that observed in corresponding patients with centroblastic/centrocytic lymphoma. These findings suggest the possibility that patients with advanced centrocytic lymphoma occupy an intermediate position between typical low-grade and typical high-grade malignant non-Hodgkin lymphomas.

Adult↗
PubMed1981

Clinical and prognostic heterogeneity of non-Hodgkin lymphomas of high-grade malignancy.

Comparison of clinical data of 64 patients with centroblastic lymphoma, 55 patients with immunoblastic lymphoma and 31 patients with lymphoblastic lymphoma not only confirmed the original assumption of high-grade malignancy as proposed by the concept of the Kiel classification but also demonstrated distinct clinical differences, particularly between lymphoblastic lymphoma and the two other entities. Rapid lymph node enlargement as well as steep fall of survival curves within the first year after diagnosis were common characteristics. Bimodal age distribution, predominance of males and early generalization of disease were typical features of lymphoblastic lymphoma; elderly patients and patients with the unclassified subtypes of lymphoblastic lymphoma exhibited the worst prognosis. Whereas patients with centroblastic and immunoblastic lymphomas showed similar distribution of age, sex and initial stage of disease, patients with immunoblastic lymphoma presented more frequently with a reduced performance status and showed a poorer response to radio- and chemotherapy resulting in a worse prognosis discernible after the first year of follow-up. Generalization during course of the disease was significantly more frequent in immunoblastic than in centroblastic lymphoma.

Adolescent↗
PubMed1979

[Continuous determination of the blood density during haemodialysis (author's transl)].

Application of the mechanical oscillator technique for measurement of blood density, in combination with a reference method for the determination of the absolute value of the blood volume, enables precise and continuous monitoring of fluid shifts during haemodialysis. The significant correlation between blood volume and density or plasma volume and density allows each variation in blood volume to be calculated from the blood density and the slope of the regression line for each individual patient. The possibility of taking continuous measurements and the high accuracy of the mechanical oscillator technique commends this method for the measurement of short-term and small fluid shifts.

Blood Pressure↗
PubMed1979

[Application of the mechanical oscillator technique for the measurement of blood density and hematocrit (author's transl)].

Density measurements were performed with an accuracy of 0.01 g/l by means of a density meter based on the "mechanical oscillator technique", on human whole blood, on plasma, and on erythrocyte concentrates. A highly significant correlation between blood density and hematocrit was found. If plasma and red cell densities are known, hematocrit can be estimated more precisely than using the centrifugation method. This fact is important if small variations of the hematocrit are to be determined. Such variations can be produced, e.g., by alteration of the transcapillary filtration equilibrium. Furthermore, the statistical distribution of plasma and erythrocyte densities allows to determine the range of variation of blood densities for certain hematocrit values and vice versa.

Blood↗
PubMed1979

[On the contamination of the citric acid fermentation. I. The contamination by representatives of Enterobacteriaceae (author's transl)].

Among the most dangerous bacterial contaminations of the citric acid fermentation is the so-called brown contamination, which is called forth by non pathogenic representatives of Enterobacteriaceae like Escherichia coli, Aerobacter aerogenes, Enterobacter cloacae and Proteus vulgaris, while other bacteria do not produce the mentioned contamination. There is given a comprehensive characterization of the brown contamination. Enterobacteriaceae interrupt the growth of the mycelium of the mold Aspergillus niger and stop the production of citric acid, produce a characteristic repugnant smell and reduce nitrate to nitrite. In a case of weak contamination the phenomena of the brown contamination do not appear, but the yield of citric acid is rather low. The contamination may be transferred successfully within the first 24 hrs. of incubation. The effect of the bacteria is determined by their virulence and some other factors.

Aspergillus niger↗
PubMed1979

[On the contamination of the citric acid fermentation. II. Sodium 5-nitrofurylacrylate as an antiseptic against representatives of the Enterobacteriaceae (author's transl)].

In context with the first communication which deals with the characterization of the so-called brown contamination called forth by Enterobacteriaceae in the citric acid fermentation of molasses, the present paper describes the screening of antiseptic substances able to suppress the contamination mentioned without damaging the normal growth of the producing mould Aspergillus niger and its ability of producing citric acid. Among the substances tested the sodium salt of 5-nitrofurylacrylic acid (5-NFA) excelled partly because of its antiseptic effect in relatively small concentrations and partly because the mould tolerates appreciable amounts of this antiseptic. Therefore there may be applied, in the presence of a heavy contamination, relatively high concentrations of the antiseptic without fear of damaging the producing mould. Usually a dose of 10 to 15 mg 5-NFA in 11 of medium was sufficient to suppress the brown contamination.

Acrylates↗
PubMed1979

[Thibièrge- and Weissenbach-syndrome (author's transl)].

Subcutaneous and periarticular calcium deposits in progressive systemic sclerosis usually appear due to prolonged disease. One case with 40 years' duration is demonstrated which developed extensive subcutaneous and periarticular calcium deposits as well as soft tissue calcifications around old fractures.

Aged↗
PubMed1978

[Determination of the serum protein concentration based on the measurement of density by the mechanical oscillator technique (author's transl)].

A linear relation is well established between the density and protein concentration of the serum. The measurement of protein concentration by a new technique for the determination of the absolute density, the mechanical oscillator technique, was investigated. The method is based on the determination of the resonant frequency of a mechanical bending-type, U-shaped glass tube oscillator filled with the sample. The shift in the resonant frequency of the oscillator caused by the mass of the defined volume of the sample taking part in the vibration can be used to calculate the density or protein concentration of the sample. In spite of the low specificity of the method, the interference of substances like glucose, urea or triglycerides is small. Simplicity and rapid results of high accuracy recommend the mechanical oscillator technique for the routine laboratory.

Blood Glucose↗
PubMed1978

[A solid culture medium, inducing intensive production of conidia in moulds of the species Aspergillus niger (author's transl)].

Two citric acid-producing strains of the mould Aspergillus niger, cultivated on different sporulation media recommended and well-tried for Aspergilli, showed only poor formation of conidia the harvesting of which was difficult. Starting with a sporulation medium of MOYER et al. and substituting some of the constituents and determining their optimum concentrations, two semi-synthetic media were developed, containing glycerol and/or citric acid. On these sporulation media the two strains exhibited excellent growth and formation of a dense and regular carpet of conidia which could be easily harvested. Attention was payed to the significance of the cultivation temperature. The original biochemical properties of the two strains were not altered.

Aspergillus niger↗
PubMed1977

The continuous high-precision measurement of the density of flowing blood.

The "mechanical oscillator" technique for the measurement of the density of fluids is based on the influence of mass on the natural frequency of a mechanical oscillator. The practical application of this principle was worked out by Kratky et al. (1969) and Leopold (1970). It is demonstrated in this study that the method permits the continuous high-precision measurement of the density of flowing blood in anesthetized animals. The accuracy is 10(5) g/ml, the maximum sampling rate 20/min. As found in rabbits and cats during the control state, physiological blood density changes related to spontaneous blood pressure variations are up to 2-10(4) g/ml. The method can be combined with i.v. injections of isotonic and iso-oncotic solutions to determine cardiac output and blood volume on the basis of a "density dilution" principle. Since the density of the interstitial fluid is lower than that of blood, fluid shifts through the capillary walls can be detected. The effects of hypertonic glucose and of hyperoncotic dextran have been examined. Changes in the density of the arterial blood appear within 10 s after i.v. injection of these fluids. Similarly, density changes result from hemorrhage and reinfusion. During and after i.v. administration of vasoactive drugs (noradrenaline, angiotensin II, acetylcholine), marked transient changes in blood density are seen which obviously reflect the effects of fluid shifts through the capillary walls. During hemorrhagic hypotension we found periodic variations in the blood density synchronous with spontaneously occurring Mayer waves. The new method seems to be a promising tool for investigations physiological and pathological capillary fluid dynamics.

Acetylcholine↗