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Biomedical subjects

P L Howard

Publications and source records attributed to P L Howard.

At least 19 recordsLinked to original sources
PubMed1991

Postthaw stability of fibrinogen in cryoprecipitate stored between 1 and 6 degrees C.

The fibrinogen activity in thawed cryoprecipitate stored between 1 and 6 degrees C is maintained essentially unchanged in most bags for a month. Occasionally, a bag will have a reduction in fibrinogen. If pooling has not occurred, thawed cryoprecipitate should be useful as a source of fibrinogen for a period of time considerably in excess of the 6 hours allowed for its use as a source of factor VIII or von Willebrand factor.

Chemical Precipitation↗
PubMed1991

Polymerase chain reaction and allele-specific oligonucleotides in paternity testing of the deceased.

The assignment of paternity when the alleged father has died is now possible by use of a variety of allele-specific oligonucleotides after amplification of genomic DNA by the polymerase chain reaction (PCR). Issues relating to the inheritance of estates may be decided on fact rather than allegation. PCR-based genotyping of DQ alpha haplotypes from paraffin-embedded tissue of the deceased was used to prove non-paternity in the case reported here. Because the child was female, it was also possible to confirm the exclusion by using a second polymorphic site located in the factor VIII gene on the X chromosome.

Alleles↗
PubMed1990

Amplification of the c-erb B-2 oncogene and prognosis of breast adenocarcinoma.

Fifty patients with typical infiltrating ductal adenocarcinoma of the breast were studied for amplification of the c-erb B-2 (neu/HER-2) oncogene within the tumor DNA. Amplification, ranging from 4 to greater than 50 copies per cell, was observed in 17 (34%) of the samples. The presence of c-erb B-2 gene amplification was not significantly correlated with patient survival, metastases, recurrence, or overall histologic grade. However, amplification was significantly associated with increased mitotic activity. Also, amplification of c-erb B-2 showed a significantly negative association with both progesterone and estrogen receptor presence. Progesterone receptor presence correlated significantly with survival.

Adult↗
PubMed1989

Hemoglobin Southampton (Casper): characterization of the base mutation.

Hemoglobin Casper is characterized by the substitution of cytidine for thymidine in condon 106 of the beta globin gene. This substitution results in the creation of a new restriction site for Msp I but not for the isoschizimer Hpa II. The restriction pattern following digestion with Msp I reveals a 9.9-kb fragment not seen in normal individuals or following digestion of Casper DNA with Hpa II. This finding confirms the predicted base mutation and indicates that the cytidine in the newly acquired CpG site is methylated.

Adult↗
PubMed1988

Spontaneous mutation in the male gamete as a cause of hemophilia A: clarification of a case using DNA probes.

The carrier status of two sisters of the mother of a hemophilic boy was clarified by the use of DNA probes in a family with a single case of hemophilia A and no family history of the disease. The extragenic polymorphic site demonstrated by probe DX13 (locus DXS15) and the intragenic polymorphic site demonstrated by BgI I digestion and a factor VIII partial cDNA probe indicated that the mother of the index case carried a mutation in the X-chromosome received from her nonhemophilic father rather than the X-chromosome received from her mother. In spite of equivocal coagulation data, the mother's two sisters were shown not to be carriers of hemophilia A.

DNA↗
PubMed1983

Thyroid function tests in thyroid and nonthyroid disease.

Modern day evaluation of thyroid disorders requires a combination of accurate clinical judgement and reliable, sensitive, and specific thyroid functions tests. Principle among the latter are thyroxine (T4) 3, 5, 3'-triiodothyronine (T3), and thyroid-stimulating hormone (TSH). Also playing an important role in special situations are free thyroxine, an assessment of bound and unbound thyroid-binding globulin, TRH stimulation, long-acting thyroid stimulator (LATS), antibodies to thyroid hormone and to thyroid receptors. Basic to interpretation of these tests in the clinical setting is a comprehension of the relationship of the hypothalamus, the pituitary, and the thyroid gland as well as a knowledge of the peripheral metabolism of thyroxine and triiodothyronine. The role of each of these laboratory tests in the evaluation of hyper- and hypometabolic states, their alteration in nonthyroid and other endocrine disorders, and the effects of environmental and physiological factors on these tests are reviewed.

Adult↗
PubMed1982

Gamba leg.

Explore the source record for details and available documents.

Adult↗
PubMed1982

Rapid thawing of fresh frozen plasma.

Fresh frozen plasma (FFP) normally requires about 45 min to thaw in a 37 degrees C water bath when placed inside an additional plastic overbag. That relatively prolonged time may result in non-utilization or delays in delivery of the product, especially, during emergency surgery. One report recommends the use of a microwave oven to overcome those problems. Most blood banks do not have microwave ovens but usually do have water baths at 56 degrees C. Ten units of FFP thawed inside plastic overbags at 37 degrees C required 49.5 +/- 3.9 min and 22 units thawed at 56 degrees C required 28.3 +/- 4 min to thaw. Removal of the plastic overbag reduces the thawing time to 12-13 min at 56 degrees C. The activity Factor V was 85 +/- 15% (65-106%) at 37 degrees C and 80 +/- 21% (47-118%) at 56 degrees C. Factor VIII activity was 86 +/- 21% (59-118%) at 37 degrees C and 90 +/- 37% (46-225%) at 56 degrees C. There were no demonstrable alterations in fibrinogen, PT, APTT, Factor II, VII, IX, and XI between the two thawing temperatures, even after 24 hours of storage at 4 degrees C.

Blood Banks↗
PubMed1977

Creatine phosphokinase isoenzymes: a comparison of a kinetic and electrophoretic method in the diagnosis of myocardial infarction.

A comparison has been made of the results of the levels of the MB isoenzyme of creatine phosphokinase by a kinetic and an electrophoretic method performed on patients suspected of having myocardial infarction. Reviewed in depth are those cases in which discrepant results have occurred. On the basis of the combined clinical and laboratory data, the kinetic method is a more sensitive but less specific indicator of myocardial necrosis. Thus, the kinetic method may be used as a screening test, with confirmation of positive results by electrophoresis.

Clinical Enzyme Tests↗
PubMed1975

The influence of diet on response to hemorrhagic shock.

Prior nutrition is known to influence tolerance to hypovolemic shock. This study was undertaken to determine the influence of dietary composition on the response of animals subjected to hypovolemic shock. Particular attention was directed to the role of high and low protein diet content with a proportionate change in carbohydrate content to yield isocaloric diets. Rats were placed on one of three diets and were subsequently subjected to shock either by 1) hemorrhage to a pre-determined mean arterial blood pressure, or by 2) hemorrhage of a pre-determined volume of blood based on per cent of body weight. Serial measurements were made of blood pressure, blood volume removed, survival time,hematocrit, blood glucose, pH and blood gases. The results indicate that a high protein diet does not prolong tolerance to recurrent blood loss but there is a greatly reduced tolerance to hemorrhage shock in rats whose body weight was maintained on a low protein/high carbohydrate diet. The latter animals also exhibited impaired refill of plasma volume and a paradoxical, continuing hyperglycemic response during hypovolemia. This study suggests that although an abundant supply of blood glucose is available as an energy source, glucose uptake in the peripheral tissues is inhibited during hypovolemia by unknown mechanisms and thus homeostasis is curtailed. The protein content of the diet may be a critical factor in carbohydrate use during shock.

Animal Nutritional Physiological Phenomena↗
PubMed1975

Hemodynamic and metabolic alterations in peripheral tissue during hemorrhagic shock.

In dogs subjected to hypovolemic shock (modified Wiggers model) severe enough to decrease the arterial flow in an isolated hind limb by two-thirds, a marked hyperglycemia (three times control) and an increase in blood glucose AV difference (ten times control) occur. Despite the decreased arterial flow, glucose uptake by peripheral tissues increased by a factor of three within one-half hour of hemorrhage and remained elevated for several hours. Presumably, the increased glucose uptake reflects the need for more energy substrate during the hypoxic conditions of the decreased peripheral blood flow.

Animals↗
PubMedDate not supplied

Blood bank reagents: some problems related to preservatives and dyes.

Occasionally the additives used for the storage, preservation, and coloring of blood bank reagents are a source of anomalous a-glutination reactions. Discrepancies in ABO cell and serum grouping or agglutination of cells used for both antibody detection and identification may be related to the presence of these materials in blood bank reagents. These substances include acriflavin and other dyes; antibiotics, such as penicillin and neomycin; EDTA; caprylate; and occasionally saline. The literature is reviewed regarding this problem.

ABO Blood-Group System↗
PubMedDate not supplied

Principles of antibody elution.

Antibody-antigen binding depends upon ionic, hydrophobic, and hydrogen bonds, as well as van der Waals forces and three-dimensional conformation. Antibody elution techniques attempt to break those forces by alterations of ionic strength, pH, thermal agitation, and the use of organic solvents. Because of the heterogeneity of the physical forces involved in binding, no single elution technique finds universal applicability to the disruption of all types of antibody-antigen bonds.

Antibody Affinity↗