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Biomedical subjects

J Wyatt

Publications and source records attributed to J Wyatt.

At least 109 records · Page 6Linked to original sources
PubMed1990

[Sodium, potassium and calcium content in regional dishes consumed in Sonora, Mexico].

The content of sodium, potassium and calcium was determined in 15 regional dishes, by atomic absorption spectrophotometry. The Na:K ratio was high in most of the dishes due to the high sodium content and low content of potassium found. The higher sources of the studied minerals were "tortilla de harina" with 1,372.8 mg/100 g of sodium; "chorizo con papas" with 466 mg/100 g of potassium, and "calabacitas con queso" with 244.1 mg/100 g of calcium. Two of the dishes considered as desserts, "capirotada" and "arroz con leche" showed the lowest Na:K ratio (0.66 and 0.81, respectively).

Calcium, Dietary↗
PubMed1989

An audit of doctor's management of patients with chest pain in the accident and emergency department.

In a series of 604 patients attending an accident and emergency department with chest pain, the decisions made by casualty officers about admission to the coronary care unit were compared with the retrospective opinions of experienced clinical assessors who knew the results of any subsequent investigations. Of the 119 patients whom the assessors judged should have been admitted to the coronary care unit, 14 (11.8 per cent) were judged to have been discharged in error. Of the 485 patients whom the assessors judged should not have been admitted to the coronary care unit, 32 (16 per cent) were judged to have been advised admission unnecessarily. Misinterpretation of the electrocardiographic results was apparently the reason for five of the 14 false negative errors and four of the 32 false positive errors. The median time that patients who were eventually admitted to the coronary care unit spent in the accident and emergency department was 78 min.

Chest Pain↗
PubMed1989

Automated quantitation of cell density distribution and hyperdense cell fraction in RBC disorders.

An altered state of cell hydration is a hallmark of a number of RBC disorders. The two parameters most often used to characterize the state of cell hydration are (a) the complete cell density distribution profile, and (b) the fraction of cells with densities greater than a defined value. Buoyant density cell fractionation with a variety of polymers has long been the preferred method for obtaining data on cell density distribution. Although this method provides accurate and quantitative information on the state of RBC hydration, its applicability has been limited due to the time-consuming experimental procedure involved in generating the data. A recently developed light-scattering method has been used in the present study to quantitate RBC density distribution. This new method accurately quantitates both the cell density distribution profile and the fraction of dense, dehydrated cells in various RBC disorders. The ability of the automated method to generate this information rapidly makes possible objective testing of different hypotheses concerning the contributions of cell hydration and dehydration to the pathophysiology of various RBC disorders.

Anemia, Sickle Cell↗
PubMed1988

Severe exercise hypoxaemia with normal or near normal X-rays: a feature of Pneumocystis carinii infection.

To find out whether Pneumocystis carinii pneumonia (PCP) can be detected while still in an early phase by the degree of exercise-induced oxygen desaturation, arterial oxygen saturation was measured by continuous pulse oximetry in patients positive for antibody to the human immunodeficiency virus and clinically suspected of having PCP, in patients with other chest diseases, and in controls. Among patients with proven PCP 94% of those with low arterial oxygen pressures (PaO2) showed desaturation on exercise oximetry, as did 80% of those with a normal oxygen pressure at rest, whereas only 10% of patients with other chest disorders and HIV disease showed significant desaturation.

Diagnosis, Differential↗
PubMed1988

Estimation of optical pathlength through tissue from direct time of flight measurement.

Quantitation of near infrared spectroscopic data in a scattering medium such as tissue requires knowledge of the optical pathlength in the medium. This can now be estimated directly from the time of flight of picosecond length light pulses. Monte Carlo modelling of light pulses in tissue has shown that the mean value of the time dispersed light pulse correlates with the pathlength used in quantitative spectroscopic calculations. This result has been verified in a phantom material. Time of flight measurements of pathlength across the rat head give a pathlength of 5.3 +/- 0.3 times the head diameter.

Animals↗
PubMed1988

Recent results of treatment of infantile hypertrophic pyloric stenosis.

During the five year period December 1980 to November 1985, 106 infants with hypertrophic pyloric stenosis were treated. There were no operative deaths, but two late deaths occurred from associated abnormalities. The combination of preoperative rehydration, skilled anaesthesia, and the use of the Fredet-Ramstedt operation (pyloromyotomy) have virtually eliminated mortality from uncomplicated infantile hypertrophic pyloric stenosis. The most common complications were gastro-oesophageal reflux in 11 (11%), perforation of the duodenal fornix in nine (8%), and wound infection in five (5%); no wound dehisced.

Duodenum↗
PubMed1988

Anesthetic-induced corneal lesions in developmentally sensitive rats.

Developmental critical periods for the induction of abnormalities by exposure to exogenous substances need not be confined to the early embryonic stage of organogenesis. The combination of ketamine hydrochloride and xylazine, two commonly used anesthetic agents, resulted in a corneal epithelial calcium deposition in 84% of rat pups whose exposure was limited to a single injection during the third postnatal week only. Concurrent exposure to ketamine hydrochloride, xylazine, and yohimbine, an alpha 2 adrenergic receptor antagonist, resulted in corneal lesions in only 6% of rat pups so exposed. The etiology is presently not understood but may involve interference with neurally directed corneal development. Corneal desiccation may also play a role. Altered drug metabolism, and toxic interactions resulting from a changing oxygen or light milieu are less likely etiologic mechanisms. Aspects of corneal development and mechanisms by which drugs can interact with and disturb normal maturational sequences can now be approached.

Anesthetics↗
PubMed1988

Flow cytochemical patterns of white blood cells in human hematopoietic malignancies: III. Miscellaneous hemopoietic diseases.

Peripheral blood samples from 48 untreated and 20 treated patients with disease entities that directly or indirectly affect hematopoiesis [dys-myelopoietic syndrome (DMS), refractory anemia with excess blasts (RAEB) or in transformation (RAEBIT), lymphoma, myeloma, acquired immunodeficiency syndrome (AIDS), and solid tumors with uninvolved bone marrow] were measured with the Technicon H-6000 automated hematology analyzer; this instrument provides a differential count on 10(4) white blood cells (WBC) effected by means of flow cytochemistry (peroxidase content) and volume (light scatter) discrimination. Cases with DMS and RAEB showed statistically significantly lower WBC counts than normal, whereas cases with lymphoma showed significantly higher values. No disease entity demonstrated changes in mean peroxidase activity (MPA) that were significantly different from normal, although all disease entities, including cases with solid tumors, showed significantly higher (two to severalfold) proportions of cells with high peroxidase (HPX) content, probably as a reflection of a disturbance of normal hemopoiesis with the emergence of younger granulocytic forms. All cases with paraleukemia (DMS, RAEB, and RAEBIT) showed significantly higher values of large unstained cells (LUC), whereas cases with lymphoma showed significantly lower LUC values. There were no statistically significant differences for any parameter (WBC counts, MPA, HPX, or LUC) among the paraleukemia subtypes. However, based on the displayed trends, a case presenting with dyserythropoiesis, relatively low WBC counts, abnormal HPX values, and LUC below 10% should be suspected for RAEB, whereas the presence of greater than 10% LUC and almost normal or even slightly elevated WBC counts should suggest a more accelerated phase of RAEB. Unless complicated by a leukemic phase, cases of lymphoma or myeloma did not display changes in any of the parameters analyzed by the H-6000. Similarly, patients with AIDS had no overt changes other than a trend to lower WBC counts with occasionally higher or lower absolute lymphocyte counts than normal. The peripheral blood of patients with solid tumors displayed a slight increase in HPX, suggesting an indirect effect on hemopoiesis since careful workup failed to demonstrate bone marrow involvement. Our data demonstrates that an H-6000 analysis has a role in the evaluation and follow-up of all these entities particularly to document leukemic transformation of either lymphoma, myeloma, or RAEB.

Flow Cytometry↗
PubMed1987

Early myocardial revascularization for postinfarction angina.

In 1983 and 1984, coronary artery bypass grafting (CABG) was performed on 107 consecutive patients for postinfarction angina. In each instance, CABG was done within 30 days of infarction. Sixty-three patients (59%) required intravenous administration of nitroglycerin and/or the intraaortic balloon pump (IABP) for relief of angina. Oral medications relieved angina in the remaining 44 patients. Thirty-eight patients underwent CABG 7 days or less after the infarction (Group 1), 25 received it between 8 and 15 days later (Group 2), and 44 had CABG between 16 and 30 days later (Group 3). There were 9 in-hospital deaths: 4 in Group 1, 2 in Group 2, and 3 in Group 3. Thirteen patients needed the IABP for hemodynamic stability as well as relief of angina. Even when the patient was stable hemodynamically, death was more likely to occur among these 13 patients if CABG was conducted within 7 days of infarction. Follow-up was 94% complete at 29.4 months. Eighty-six percent of patients were asymptomatic or in New York Heart Association Functional Class I, and 6% were in Class II. There were 2 late deaths. CABG for angina can be accomplished within 30 days of an acute infarction with good results. The exception to this rule is the patient in whom shock develops after a myocardial infarction and who, despite stabilization, receives CABG within 7 days of the infarction.

Angina Pectoris↗
PubMed1987

Flow cytochemical patterns of white blood cells in human haematopoietic malignancies. II. Chronic leukaemias.

Peripheral blood samples from 73 patients with chronic leukaemia were measured with the Technicon H-6000 automated haematology analyser to provide flow cytochemical (peroxidase content) and volume (light scatter) discriminated scattergram patterns. For chronic granulocytic leukaemia (CGL), these patterns were so reproducible and distinct that they allowed an immediate diagnosis even without the benefit of microscopic examination. Relative and absolute basophilia was an invariable feature, and remained detected by the H-6000 even when the patient was in haematologic and cytogenetic remission or progressed into blast crisis (BC). Most patients in BC also demonstrated an inordinately high number of large unstained cells (LUC) and high proportions of 'lymphocytes' (small blasts with no peroxidase content by visual inspection). Thus, for patients with CGL, LUC values above 10%, and/or steady increments in the proportion of 'lymphocytes', merit concern as these changes may herald an accelerated phase of disease. The scattergram pattern of untreated chronic lymphocytic leukaemia (CLL) showed a dense accumulation of data points within the lymphocytic 'box' with a small cluster of granulocytic elements. Most patients also had a frankly abnormal proportion of LUC. Sixteen patients with CLL were compared for ratios of LUC to lymphocytes and stage of disease; patients with the most advanced stage (IV) had the highest, statistically significant values, than the patients with more benign disease. Thus, it is possible that follow up with this instrument of patients with CLL will also allow early detection of an impending prolymphocytoid transformation (accelerated phase) of this disease.

Cell Separation↗
PubMed1987

Flow cytochemical patterns of white blood cells in human haematopoietic malignancies. I. Acute leukaemias.

Peripheral blood samples from 118 patients with acute leukaemia (68 untreated; 50 treated) were measured with the Technicon H-6000 automated haematology analyser. This instrument provides, in addition to measurements of the classical haematology parameters (i.e. cell counts, haemoglobin concentration, etc.), a differential count on 10(4) WBC effected by means of flow cytochemistry (peroxidase content) and volume (light scatter) discrimination. Disregarding RBC and platelet counts and their volume distribution profiles, the most important diagnostic parameters for leukaemic disease were the WBC count, the WBC differential count, and the proportions of large unstained cells (LUC) and high peroxidase (HPX) cells obtained by the automated differential count as well as the mean value of the WBC peroxidase content distribution (MPA). Granulocytic leukaemias had lower MPA than normal and lymphocytic leukaemias had MPA values above normal. M1 leukaemias were also characterized by large proportions of LUC and low fractions of HPX, while M2 leukaemias showed low LUC with high HPX. M3 leukaemias had low LUC and very high HPX. M4 leukaemias had large LUC and 'monocytic' components and a modest fraction of HPX. M5 leukaemias had very large numbers of LUC, 'monocytes' and 'lymphocytes' and a normal HPX. For M1 leukaemia, the presence of less than 7% LUC following induction treatment was related to morphological changes of normal cells induced by chemotherapy while LUC above 10% usually indicated unsuccessful induction associated with the presence of residual blasts. If treatment was successful, M2 and M3 leukaemias characteristically decreased their HPX population. All M4 leukaemias studied by us failed to enter remission and continued to display high proportions of HPX and LUC. Similarly, most M5 leukaemias had a poor response to treatment and always showed a very high proportion of LUC. Untreated lymphocytic leukaemias demonstrated high LUC, normal HPX and a high proportion of 'lymphocytes'. Hairy cell leukaemias showed almost equal proportions of 'lymphocytes' and LUC. Successful chemotherapy of all lymphoid leukaemia entities was associated with rapid decreases in LUC, slower decrements of 'lymphocytes' and moderate and transient increments in HPX. Thus, flow cytochemistry can assist not only in the segregation of acute leukaemias along with FAB classification with nonmorphologic criteria, but also in the follow up of patients with these diseases.

Acute Disease↗