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Biomedical subjects

K Cash

Publications and source records attributed to K Cash.

14 recordsLinked to original sources
PubMed2001

A novel method for correlating internal and external structure of individual myelinated nerve fibres.

A new method is described that enables longitudinal and cross sections of an individual nerve fibre to be cut at multiple specified sites along the fibre by the use of a unique marker system. In this way the internal structure of the fibre can be correlated with the external appearance. Individual myelinated nerve fibres are teased apart in epoxy resin and mounted onto a carbon-coated slide, and after orientation and marking of specific sites of interest are snap frozen to liberate the orientated and marked fibres for embedding on the surface of an epoxy resin block for subsequent longitudinal or transverse sectioning. This method is particularly useful for the correlative study of the myelin-axon relationships.

Axons↗
PubMed2001

Focal myelin swellings and tomacula in anti-MAG IgM paraproteinaemic neuropathy: novel teased nerve fiber studies.

Focal myelin swellings and tomacula in teased nerve fibers from a case of IgM anti-myelin-associated glycoprotein (MAG) paraproteinaemic neuropathy were examined using a novel technique. Five different morphologic abnormalities were identified--myelin sheath outfolding, myelin sheath infolding, enlargement of the adaxonal space, myelin degeneration, multiple increased concentric loops--and a combination of these structural abnormalities often occur in association with myelin degeneration. Similar structural changes were found in externally normal segments of teased fibers without evidence of myelin swelling or tomacula from the same case. These structural abnormalities are consistent with a disturbance of the normal adhesion functions of MAG in the maintenance of axon-myelin relationships.

Aged↗
PubMed2001

Diffuse geographic distribution of herbicides in northern prairie wetlands.

The concentrations of herbicides in water from wetlands on landscapes where herbicides are not used should be less than on farms with moderate (conventional farms) and intense (minimum-till farms) herbicide use. In general, this hypothesis was not supported for wetlands situated in the Boreal Plains Ecozone of central Saskatchewan, Canada. The overall detection frequency of 10 commonly used herbicides was not significantly different among wildlife habitat with no pesticide use (44.4%), farms with no pesticide use (51.6%), conventional farms (54.9%), and minimum-till farms (56.5%, chi 2 = 5.64, p = 0.13). The herbicides (4-chloro-2-methylphenoxy) acetic acid (MCPA), 2,4-dichlorophenoxyacetic acid (2,4-D), bromoxynil, dicamba, mecoprop, and diclorprop accounted for 87% of all detections. In general, detection frequencies and concentrations of individual herbicides were similar on all land-use types. For example, the mean concentration of 2,4-D in water on the four land types ranged from 0.12 +/- 0.104 to 0.26 +/- 0.465 microgram/L, and MCPA ranged from 0.08 +/- 0.078 to 0.19 +/- 0.166 microgram/L. However, in the year of application, mean concentrations of MCPA and bromoxynil, but not 2,4-D, were significantly higher by about twofold in wetlands situated in fields where these herbicides were applied compared with all other wetlands. We propose that many agricultural pesticides are rapidly lost to the atmosphere at the time of application by processes such as volatilization from soil and plant evapotranspiration. Then, the herbicides used throughout the region may be directly absorbed to the surface of wetlands from the atmosphere, or they become entrained in local convective clouds, and are redistributed by rainfall in a relatively homogenous mixture over the agricultural landscape. The low levels of individual herbicides we found in most of the wetland waters would not cause chronic effects to aquatic biota.

Geography↗
PubMed2000

Do we need managers?

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Education, Nursing, Baccalaureate↗
PubMed1999

Anti-G in a pregnant patient.

BACKGROUND: Anti-G is a red cell (RBC) antibody of the Rh system. It has been described in pregnant women only in association with anti-D or anti-C; therefore, the ability of this antibody alone to cause hemolytic disease of the newborn is uncertain. One case in which this antibody caused no clinical sequelae is reported. CASE REPORT: The patient was a 35-year-old primigravida with type O, D-, C-, E-, c+ RBCs who was given 4 units of type O, D- allogeneic RBCs and 2 units of autologous RBCs 2 years antepartum. She was found to have anti-D and anti-C by an outside laboratory as part of a routine prenatal work-up. Further evaluation by our laboratory revealed the presence of anti-G and possible anti-C without anti-D. Titers at 22 weeks' gestation were 64 against r'r RBCs and 16 against R2R2 RBCs; these remained unchanged throughout the pregnancy. Amniocentesis performed at Weeks 28 and 32 showed no evidence of hemolytic disease of the newborn. A healthy 3.3-kg infant was delivered at 36 weeks' gestation. Prophylactic Rh immune globulin was administered antepartum and postpartum. The infant's RBCs were type O, D+, c+ C-, E-, and the direct antiglobulin test was positive. An acid eluate prepared from the baby's RBCs revealed anti-G. The total bilirubin was 5.5 mg per dL at birth, and the hematocrit was 66 percent. Total bilirubin peaked on Day 5 at 11.9 mg per dL, and no therapeutic intervention was required. CONCLUSIONS: Anti-G alone caused little if any fetal or neonatal hemolysis in this case. Although further study is needed, invasive fetal monitoring may be unnecessary if anti-G is the sole cause of fetomaternal RBC incompatibility.

Adult↗
PubMed1997

Social epistemology, gender and nursing theory.

A major claim for nursing theory is that it contributes to the generation of a body of nursing knowledge that will be important in the definition of nursing's boundaries. It is argued here that the epistemic authority of nursing knowledge is determined by factors such as the gender structure of nursing. This means the knowledge products of nursing will be given low epistemic status by both nurses and non-nurses. The implications of this argument, in terms of professionalisation and the project to develop nursing theory, are examined.

Female↗
PubMed1995

Benner and expertise in nursing: a critique.

This paper examines the work of Benner (From Novice to Expert: Excellence and Power in Clinical Nursing Practice. Addison-Wesley, Menlo Park, CA, 1984) on expertise in clinical nursing. The philosophical foundations of her work are explained as well as the work located within the wider context of the use of Heideggerian philosophy. Various criticisms of her study are developed in relationship to her methodology and her interpretation of nursing. It is argued that she represents a retreat into tradition and authority in nursing.

Animals↗
PubMed1990

Nursing models and the idea of nursing.

The Wittgensteinian idea of family resemblances and meaning is explained. The idea of nursing is examined from this standpoint as are the knowledge claims of several influential nursing models. It is argued that the task of building a general model of nursing is theoretically impossible. The political and educational implications of the above argument are developed.

Education, Nursing↗
PubMedDate not supplied

Difficulties in identifying antibodies in the Dombrock blood group system in multiply alloimmunized patients.

BACKGROUND: Although red cell (RBC) antibodies of the Dombrock blood group system have been reported to cause acute and delayed hemolytic transfusion reactions, the difficulty in identifying these antibodies in patients with multiple RBC alloantibodies has not previously been discussed. The cases of four sickle cell disease patients who developed Dombrock system antibodies after transfusion, three of which were discovered in association with hemolytic transfusion reactions, are reported. CASE REPORTS: Patient 1 was a 36-year-old woman with multiple RBC alloantibodies. Because of the lack of an increment in hematocrit after transfusion, an investigation was performed; it revealed anti-Do(b) in the serum. Patient 2 was a 30-year-old woman with known anti-C, -E, -K, -S, -Fya, and -Bga. She had received a transfusion 10 days previously. Before further transfusion was begun, antibody identification revealed weak nonspecific reactions, which were thought to be HLA antibodies. She developed acute hemolysis during RBC exchange for acute chest syndrome; anti-Doa was identified in both the serum and eluate. She received 2 units of Do(a-) RBCs without complication. Patient 3 was a 35-year-old woman with known anti-C, -E, -K, -Fya, and -N and a warm autoantibody. Two weeks after transfusion, she had a delayed hemolytic transfusion reaction coincident with the identification of anti-Doa. Patient 4 was a 33-year-old woman with known anti-C, -V, -K, -Fya, -Fy3, Jkb, -S, -N, and -Ytb, who developed anti-Doa 8 weeks after transfusion. CONCLUSION: An association of Dombrock blood group system antibodies with hemolytic reactions is demonstrated in alloimmunized sickle cell disease patients. In all four cases, identification of Dombrock system antibodies was delayed because high-titer low-avidity antibodies, HLA antibodies, or autoantibodies were thought to explain the serologic findings. The presence of Dombrock system antibodies should be considered when unexplained serologic reactivity occurs during antibody identification in this population.

Adult↗
PubMedDate not supplied

Structural abnormalities of the cricopharyngeus muscle in patients with pharyngeal (Zenker's) diverticulum.

Recent manometric and radiological studies suggest that the upper oesophageal sphincter has poor compliance in patients with a pharyngeal (Zenker's) diverticulum. To test the hypothesis that this phenomenon is related to structural changes within the cricopharyngeus muscle we examined, histologically, muscle strips from 14 patients with a Zenker's diverticulum and compared them with control tissue obtained at autopsy from 10 non-dysphagic individuals. The cricopharyngeus muscle from patients and controls differed from inferior constrictor muscle by virtue of type 1 fibre predominance and greater fibre size variability. Ragged red fibres and nemaline bodies are a normal finding in the cricopharyngeus. Marked differences were observed in the cricopharyngeus muscle of Zenker's patients which demonstrated fibro-adipose tissue replacement and fibre degeneration. It is concluded that these structural changes may account for the observed diminished upper oesophageal sphincter opening and dysphagia in patients with Zenker's diverticulum.

Aged↗