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Biomedical subjects

D Strauss

Publications and source records attributed to D Strauss.

At least 55 records · Page 3Linked to original sources
PubMed1996

Predictors of mortality in children with severe mental retardation: the effect of placement.

OBJECTIVES: This study was undertaken to assess the predictors of mortality in severely disabled children with mental retardation, and to compare risk-adjusted mortality rates for those living in institutions with rates for those living in the community. METHODS: Statistical analysis was performed on a set of 24,469 person-years, derived from a population of all children with severe mental retardation and a fragile medical condition who are registered with the California Department of Developmental Services. Variables included age, several measures of mobility, the presence or absence of tube feeding, the level of retardation, and certain adaptive skills. RESULTS: Reduced mobility and the use of tube feeding were associated with a large increase in mortality risk. Own home residence and community care facilities have an estimated 25% higher risk-adjusted odds on mortality than institutions and health facilities. CONCLUSIONS: The differential mortality in the placements points to a possible effect of quality of care. One consequence of the current trend toward deinstitutionalization may be an increased mortality rate in children with severe developmental disability.

Adolescent↗
PubMed1996

Mortality of people with mental retardation in California with and without Down syndrome, 1986-1991.

Mortality of people with mental retardation receiving services in California was examined. The large population (N = 118,653) enabled us to work directly with mortality rates at specific ages. Up to about age 35, mortality rates of people with Down syndrome were comparable to those of people with mental retardation due to other causes. Subsequently, the increase was much more rapid in the group with Down syndrome. Mortality rates of individuals with Down syndrome doubled every 6.4 years compared to 9.6 years for people without Down syndrome. Life tables were constructed; the remaining life expectancy of a 1-year-old child with Down syndrome with mild/moderate retardation was 55 years and with profound mental retardation, 43 years.

Adolescent↗
PubMed1996

Comparative mortality of people with mental retardation in institutions and the community.

The role of institutions has come into question in recent decades, and the size of the institutionalized population has been drastically reduced. Risk-adjusted mortality rates in institutions and the community in California from 1980 through 1992 were compared, with the aim of improving our understanding of the capacity of the community health system to support deinstitutionalization. Risk-adjusted odds on mortality were estimated to be 72% higher in the community than in institutions. Some problems with health care delivery in the community were reviewed; these may help account for the difference. Consumers and guardians should weight these considerations when making choices between institutional versus community-based care.

Activities of Daily Living↗
PubMed1996

Behavioral capabilities and mortality risk in adults with and without Down syndrome.

Among adults with mental retardation, mortality rates for those with Down syndrome are higher than for those without Down syndrome. We studied age-related changes in functioning and their relation to subsequent mortality in adults with mental retardation. Among people without Down syndrome, recent loss of basic skills was associated with substantially elevated mortality rates. This was not so in the Down syndrome group, however. Adults with Down syndrome tended to experience regression in adaptive behavior earlier than did those without Down syndrome. Incidence rates in the two groups diverged subsequent to age 40. Adults without Down syndrome, however, did also tend to regress when older.

Activities of Daily Living↗
PubMed1990

[Improving the quality of washed and buffy coat-free erythrocyte concentrates].

Washing buffy-coat free erythrocyte concentrates three times in bottles used for blood storage will diminish their leukocyte content to 0.22 +/- 0.11 x 10(9) per TE (= 9% of the initial value in whole blood, and the thrombocyte content to 0.3 +/- 0.5 x 10(9) per day (= 2% of the initial value in whole blood). Even 50% of leukocytes (mainly lymphocytes) and 80% of thrombocytes are eliminated simply by buffy coat separation. 30% of erythrocytes are lost by the washing process. Due to increasing haemolysis (0.22%) a subsequent storage of 24 hours should not be exceeded for washed erythrocyte concentrates. Further quality parameters, such as morphological index, pH, ATP, 2,3-P2G and K+ and Na+, were investigated. As far as selected quality parameters are concerned, washing erythrocyte concentrates three times in bottles for blood storage may be compared with washing them once in blood bags. The present findings confirm the conclusion that the washing of erythrocyte concentrates with a solution of sodium chloride in order to eliminate leukocytes may for the most part exclude non-haemolytic febrile transfusion reactions, but not immunization. More effective procedures of eliminating leukocytes, such as filtration, TTK or even glycerin, treatment of erythrocyte concentrates without cryoconservation, are indispensable.

2,3-Diphosphoglycerate↗
PubMed1990

[P-31 NMR studies of in vivo regeneration of preservative-induced changes in 2,3-diphosphoglycerate content of erythrocytes].

In this study, we analyzed the regeneration kinetics and the reversibility of the 2.3-DPG reduction in stored red cells after transfusion. Within 3 h after transfusion the 2.3-DPG levels raised up to 40% of the patients' prior 2.3-DPG concentration, although the 2.3-DPG content of the transfused red cells was less than 10% of before. The complete regeneration of the 2.3-DPG concentration occurred after 36 to 48 h after transfusion. There was a close correlation of the results obtained by P-31-NMR and enzymatic determination of DPG.

2,3-Diphosphoglycerate↗
PubMed1989

[Erythrocyte volume distribution curves: a parameter for evaluating erythrocyte preparations].

The volume distribution of erythrocytes in ACD-AG blood and in human erythrocyte concentrations was investigated by means of computer-assisted techniques of hematological analysis. The storage-dependent distribution was described by the content of discrete class areas. Erythrocytes with a volume below 72 fl are only slightly capable of changing their volume. Their condition predisposes them to selection in the receiver's organism. Their percentage amount correlates with the share of cells ineffective of transfusion. The concentration of cells with a volume above 72 fl is discussed with ACD-AG blood (78% on the 42nd day), with CDS-AG erythrocyte concentrate (66% on the 20th day) and with SAG-M erythrocyte concentrate (74% on the 35th day) together with findings about the transfusional survival rate.

Blood Preservation↗
PubMed1987

[Preparation of leukocyte-poor erythrocyte concentrates by glycerin treatment and washing].

The discontinuous washing procedure of red cell concentrates with saline was modified in order to improve the removal of leucocytes and platelets. It was achieved by glycerolization and deglycerolization without freezing and thawing. The elimination rate of leucocytes amounted to 99.9% and of platelets to 97.4% related to whole blood. A unit of red cell concentrate prepared from 400 ml of donated blood contained a total of (0.001 +/- 0.003) X 10(9) leucocytes and (2.35 +/- 1.33) X 10(9) platelets. The relatively high elimination rates are comparable with those obtained by filtration and cryopreservation, respectively. The whole procedure performed in glass bottles required one hour more than washing three times without glycerolization. A further improvement of the procedure should be directed towards saving time in processing and towards lowering the loss of red cells that is still 20%.

Blood Platelets↗
PubMed1987

[Effects of different saccharose and electrolyte concentrations on preserved erythrocytes].

Preservation solutions for buffy coat-free red cell concentrates with sucrose concentrations from 234 decreasing up to 15 mmol per 1 solution were tested. The hemolysis rate increased from 0.5 up to 1.9% by decreasing the sucrose concentration. The red cell volume was unchanged at low sucrose concentrations. No differences were noticed in ATP content and morphological changes. A considerable extracellular pH shift at high sucrose concentration exists only at the beginning of storage. A sucrose concentration of 30-50 mmol/l solution (3-5 mmol per unit red cell concentrate) at an ionic strength of 0.16 proves to be most suitable.

Adenosine Triphosphate↗
PubMed1987

Preservation of resuspended red cell concentrate. Red cell volume and hemolysis.

Sucrose in a concentration of 30 to 50 mmol/l preservation solution (10-20 mmol/l red cell concentrate (RCC) and 3-5 mmol per unit RCC) and an ionic strength of about 0.16 avoid changes of red cell volume during 6 weeks of storage. Increasing sucrose concentrations up to 80 mmol/l RCC decrease the hemolysis. But a sucrose concentration of only 10 mmol/l RCC causes an acceptable low hemolysis rate of 0.25% after 35 days of storage in PCV FENWAL plastic bags. Sucrose can be replaced by mannitol or sorbitol at the same final concentration. Changes in red cell metabolism and viability will not be expected.

Blood Preservation↗
PubMed1987

Preservation of resuspended red cell concentrate. Metabolism and survival rate of stored red cells.

The sucrose-poor, electrolyte-rich SAG-sucrose preservation solution for red cell concentrates (RCC) proves to be superior to the sucrose-rich electrolyte-poor CDS-AG solution. After 35 days about 50% of the initial ATP were found and the 24 hours posttransfusion survival rate amounted to 76%. The replacement of sucrose by mannitol or sorbitol did not influence the metabolism of red cells. Guanosine-final concentration 0.4 mmol/l RCC-slightly improved the maintenance of ATP and morphology.

Adenosine Triphosphate↗
PubMed1987

Preservation of resuspended red cell concentrate. Release of vesicles from stored red cells.

The effect of carbohydrates (sucrose, mannitol) and guanosine on red cell vesiculation was studied during storage of red cell concentrates (RCC) in glass bottles and plastic bags for 35 days. The course of vesicle release was followed by measuring acetylcholinesterase activity. It was found that sucrose and mannitol reduce the loss of membrane microvesicles. Preservation of red blood cells (RBC) in plastic bags results in a drastically retarded vesicle release.

Blood Preservation↗
PubMed1987

Preservation of resuspended red cell concentrate. Analysis of purines, nucleosides and nucleotides in stored red cells.

Purine nucleotides of red blood cells (RBC) during storage in two different media with addition of adenine/nicotinamide (NAP) or adenine/guanosine (CDS-AG) were estimated by HPLC. Synthesis of guanine nucleotides reached a maximum after 14 days in RBC stored with adenine/guanosine. The higher adenine concentration in the NAP solution (3 mmol/l) did not increase adenine consumption and the ATP-level of the erythrocytes. The adenylate energy charge (AEC) of RBC decreased from 0.91 to 0.63 during 42 days of storage in CDS-AG solution.

Adenine Nucleotides↗
PubMed1987

Renal excretion of sucrose after transfusion of sucrose containing red cell concentrates.

The elimination of sucrose from plasma and the urinary excretion after transfusions of 394 units of sucrose containing red cell concentrates (RCC) to 108 patients has been studied. 70 mmol sucrose corresponding 3 units of RCC were eliminated from the blood plasma to 90% within 3 hours and excreted by kidneys to 55-80% within 12 hours. The rate of excretion depended on the kidney function. The transfusion of RCC resuspended with the sucrose-rich CSD-AG preservation solution (80 mmol sucrose/l RCC) raised the hemoglobin concentration in patient's blood by 0.5-0.6 mmol/l related to 1 unit of RCC.

Blood Preservation↗
PubMed1987

[Elimination of saccharose from the blood and its renal excretion following transfusion of buffy coat-free erythrocyte concentrates containing disaccharides].

The elimination of sucrose from the blood and its renal excretion was analysed in 108 patients after applying a total of 394 transfusion units (TE), resuspended, buffy-coat-free erythrocyte concentrates (EK) containing 23 mmol of sucrose per TE. In transfusing 3 TE even 90% of the sucrose were eliminated from the blood during the application time and up to 99% within 3 h, nearly 80% were excreted through the kidneys within 12 h. Elimination and excretion were delayed with impaired kidney function. With respect to intravasal elimination of sucrose bilaterally nephrectomized patients have to rely on hemodialysis. Side-effects of sucrose due to extended intravasal and interstitial duration could not be observed in those patients affected with decreased kidney efficiency and after massive transfusions.

Aged↗
PubMed1987

S A G--sucrose medium for red blood cell preservation.

A preservation solution for buffy coat-free red cell concentrates (RCC) was tested. It contained sodium chloride (150), glucose (50), adenine (1.25 mmol/l) and additionally sucrose (30 mmol/l). After 35 days of storage about 50% of the initial ATP were found. The 24-hours post-transfusion survival rate amounted to 76%. The hemolysis rate was 0.25% and only 2% of the red cell membrane were released as microvesicles when plastic bags were used for storage. Sucrose can be replaced by mannitol or sorbitol at the same concentration. Guanosine (0.4 mmol per 1 RCC) slightly but not significantly improved the maintenance of ATP and the morphology as well as the membrane stability.

Adenine↗