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Biomedical subjects

E Martin

Publications and source records attributed to E Martin.

At least 541 records · Page 30Linked to original sources

Class III gene rearrangements in Thai/Chinese supratypes containing null or defective C4 alleles.

Class III gene rearrangements have been examined in Thai/Chinese individuals with supratypes bearing defective or null C4 alleles. Genomic DNA from C4 null supratypes was probed with an almost full-length 21-OH probe following digestion with Taq I and Kpn I. The HLA-B17 C4A3 BQ0 BfS DR3 Thai/Chinese supratypes (which may be associated with insulin-dependent diabetes mellitus in Orientals) lacks a 3.2 kb Taq I and a 3.9 kb Kpn I fragment hybridizing with the 21-OH probe. Similar gene rearrangements are found in Caucasoid diabetogenic supratypes HLA-B18 C4A3 BQ0 BfF1 DR3 and HLA-B8 C4AQ0 B1 BfS DR3. Interethnic comparisons suggest that class II and class III interactions may be important in disease susceptibility. By contrast, neither of two Thai/Chinese supratypes with C4AQ0 appear to have major class III gene rearrangements; disease association studies will determine the significance of C4 deficiency per se. As in Caucasoids, the electrophoretically fast C4 allele, C4A6, in Orientals has been shown to correlate with a 12 kb Bgl II fragment hybridizing with a C4 probe. It is likely that the HLA-B17 C4A6 B1 BfS DR7 supratype marks a highly conserved MHC chromosomal segment.

Alleles↗

An improved purification procedure and properties of casein kinase II from brain.

A simple and short purification procedure applicable to casein kinase II has been developed, for fully characterizing the enzyme from calf cerebral cortex cytosol. The procedure consists of four chromatographic steps: DEAE-cellulose, phosphocellulose, phosvitin-Sepharose and ATP-agarose which yields 87% pure casein kinase II. The purified enzyme shows three major bands with apparent molecular masses of 42, 38, and 27 kDa by polyacrylamide gel electrophoresis in sodium dodecyl sulfate and is self-autophosphorylated on its 27 kDa polypeptide. The enzyme shows all the characteristics described for casein kinase II from other sources: it is independent of cyclic nucleotides, calcium/phospholipids, and double-stranded poly(I).poly(C); it can utilize both ATP and GTP as phosphoryl donors and can phosphorylate both casein and phosvitin but not histone. The kinetic studies establish that the Km for ATP is 12.5 microM and 25.1 microM when using phosvitin and casein respectively as phosphoryl acceptors. The Km for phosvitin is 0.91 mg/ml and for casein 1.43 mg/ml, while the Vmax is 315 nmol/min/per mg protein and 479 nmol/min/per mg protein for phosvitin and casein respectively. The activity of the kinase is highly stimulated by KCl or NaCl, and almost completely inhibited by heparin concentrations of 1 microgram/ml (92%). This inhibition is reduced to only 33% in the presence of optimal KCl concentrations (150 mM). Spermine stimulates enzyme activity, whilst hemin produces a slight inhibition.

Animals↗

Light chain deposition disease with liver dysfunction.

Light and transmission electron microscopic study as well as immunohistochemical investigation were performed on three cases of light chain deposition disease (LCDD) with severe liver dysfunction. In two cases, the amount of light chain deposits in the liver was moderate and did not correlate with the severity of clinical and biological symptoms. Ultrastructural study demonstrated a collagenization of the Disse's space, with basement membrane-like material in association with light chain deposits. Immunohistochemical investigation showed a marked increase of collagen types I, III, and IV, as well as fibronectin and laminin in perisinusoidal space. This study suggests that collagenization of the Disse's space has a minor role in liver dysfunction. The analogy between kidney and liver lesions in diabetes and in LCDD is stressed, but the mechanism of this abnormal accumulation of matrix proteins remains unknown.

Aged↗

Light chain deposition disease presenting with hepatomegaly: an association with amyloid-like fibrils.

We report an unusual case of lambda light chain deposits without overt plasma cell dyscrasia. The clinical presentation was hepatomegaly without biochemical sign of renal involvement. Portal hypertension, spontaneous rupture of the spleen and fracture of the 12th thoracic vertebra occurred during the course of the disease. Ultrastructural studies showed that lambda light chain deposits were associated with amyloid-like deposits. This case suggests that light chain deposition disease and amyloidosis could be two expressions of the same disease.

Amyloidosis↗

Combined application of MR imaging and spectroscopy in neonates and children: installation and operation of a 2.35-T system in a clinical setting.

Published pediatric magnetic resonance (MR) imaging results are usually obtained with medium-field-strength whole-body systems, while MR spectroscopy is done on a different high-field-strength/small-bore laboratory system. The authors investigated metabolism and structural development of the brain in over 100 neonates and children with combined MR imaging and spectroscopy at 2.35 T. With a 40-cm-bore magnet, MR imaging and spectroscopy data are obtained in the same session with use of the same system. The approach demands modified technical devices and elaborate patient handling. Concepts for sedation in different age groups and for patient monitoring, as well as protocols for the combined use of imaging and spectroscopy, have been worked out. The data prove high quality of imaging and spectroscopy at 2.35 T.

Brain↗

Medical metaphors of women's bodies: menstruation and menopause.

Implicit, underlying imagery in medical descriptions of menstruation and menopause is exposed, beginning with 19th century views. Contemporary medical texts and teaching reveal two fundamental assumptions about women's bodies. First, they assume that female reproductive organs are organized as if they form a hierarchical, bureaucratic organization under centralized control. Given this assumption, menopause comes to be described negatively, as a process involving breakdown of central control. Second, they assume that women's bodies are predominantly for the control. Second, they assume that women's bodies are predominantly for the purpose of production of desirable substances, primarily babies. Given this assumption, menstruation comes to be seen negatively, as a process involving failed production, waste products, and debris. Alternative imagery that works from our current understanding of physiology, but avoids denigration of women's bodies, is suggested.

Body Image↗

[Magnetic resonance in pediatric research and clinical practice. I. What can we expect from this new method?].

Nuclear Magnetic Resonance (NMR) was first observed over 40 years ago and has recently also entered the field of human medicine. It currently attracts increasing attention from biologists and clinicians alike, and the scope of its different applications is in a phase of explosive development. Two principle developments of the MR method are taking place over the recent years and are of special interest for pediatricians and neonatologists. One involves the possibility of obtaining images from any part of the human body, somewhat similar to those obtained with computer tomography (CT), but without any radiation hazard. Today clinicians are most familiar with this mode of MR application. The other development tries to adapt the MR method of elucidating the structure of molecules used in physics, molecular biology and organic chemistry for applications in medicine, allowing to study metabolism in vivo under non-invasive conditions. Again, such studies pose no health hazards and are, therefore, applicable to neonates and small infants. They will enhance our understanding of metabolic processes during normal development and disease, especially in organs like the brain, where biopsies are virtually impossible. Recent developments combine the two methods mentioned above, in order to obtain morphological as well as metabolic information from the same organ at the same time, which may provide even better insight into pathophysiological mechanisms and their response to therapeutic measures. This article attempts to give an overview to the medical researcher, the clinician, and especially the pediatrician and neonatologist of what MR is and what we can expect from it.

Brain↗

[Histopathology of the liver during hepatic transplantation in children].

This short review deals with the role of the pathologist in a liver transplant program and summarizes the main histopathologic features of liver graft injury. The role of the pathologist is pivotal, first, during diagnostic work-up of patients prior to liver transplantation and then after transplantation in the differential diagnosis of liver graft dysfunction. The histologic features of early graft dysfunction, acute and chronic rejection, viral and bacterial infection and toxic injury are briefly described. The frequency of simultaneous pathologic processes in the transplant patient is emphasized in regard to the need of information exchange between the physician and the pathologist.

Bacterial Infections↗

Three cases of nodular regenerative hyperplasia of the liver following renal transplantation.

We report three cases of nodular regenerative hyperplasia of the liver: the clinical onset of hepatic disease occurred between 24 and 30 months after renal transplantation. Nodular regenerative hyperplasia was associated with peliosis hepatitis in two cases, and with veno-occlusive disease in one case. Two patients developed portal hypertension, but are doing well. The third patient developed jaundice and died of septic shock. We discuss the aetiological role of renal transplantation, cytomegalovirus infection, and azathioprine in the development of nodular regenerative hyperplasia of the liver.

Adult↗

[Magnetic resonance in pediatric research and clinical practice. II. Studies on the development and pathology of the brain in neonates, infants and young children].

We are investigating metabolism and morphological differentiation of the developing brain in neonates and children under non-invasive conditions combining MR imaging (MRI) with spectroscopy (MRS) on a high-field/small-bore (2.35 Tesla/40 cm) system. By the end of 1987, 116 neonates, infants and young children with various perinatal problems, congenital abnormalities and different neurological diseases have been examined with MRI. In addition, MRS studies were subsequently performed on 46 of these children using the same instrument and within the same session. The small, sometimes very sick and instable patients require careful monitoring and elaborate technical devices in the high magnetic field. We are presenting solutions for methodological and technical developments and adaptations, concepts for sedation and measurement protocols in various age groups and first results of the combined use of MRI and MRS to investigate the brain in neonates and infants.

Brain↗

[Carcinosarcomas of the bladder. Immunohistochemical study in 3 cases].

We present 3 cases of carcinosarcoma of the bladder. We discuss the value of histochemistry on their diagnosis. We compare them to similar tumors reported in the medical literature. Like fusocellular carcinoma, carcinosarcoma finally appear as a morphological variant of high grade urothelial carcinoma, often difficult to diagnose. With our present knowledge, it is not possible to propose for these tumors other therapeutic measures than those already in use for high grade urothelial malignancies, based on the level of infiltration in the bladder wall. The classic pejorative prognosis of these tumors is contradicted by the favorable evolution in some cases reported in medical literature.

Carcinosarcoma↗

[The value of measuring membrane potentials of urothelial cells using cytofluorometry in the study of tumors of the bladder. Preliminary analysis].

In the context of investigation of a prognostic marker applicable to bladder tumours, the authors propose the cytofluorometric study of the membrane potential of malignant urothelial cells using a molecular probe, 3,3' dihexyloxacarbocyanine. This preliminary study demonstrated a significant increase in the membrane potential of malignant urothelial cells in comparison with normal cells, which leads the authors to propose this cellular parameter as a new tool in the prognostic evaluation of bladder tumours.

Biomarkers, Tumor↗

[Oncocytoma of the kidney and oncocytic adenocarcinoma. 10 cases of oncocytoma].

Having studied 484 previously reported and 10 personal cases of oncocytomas we believe that the main controversies surrounding this tumor are related to the fact that the term oncocytoma is wrongly applied to all tumors with oncocytic cells. The term oncocytoma must be restricted to well encapsulated tumors, sometimes very large ones, made up solely from regular oncocytic cells. The benign clinical behavior of oncocytomas thus defined, is supported by numerous well documented observations in medical literature. Thanks to the progress made in radiology investigations and to better defined histological criteria, it is possible, by means of diagnosis with frozen sections, to practice partial surgery.

Adenocarcinoma↗

Effects of fixation and processing on the immunohistochemical visualization of type-I, -III and -IV collagen in paraffin-embedded liver tissue.

We compared the effects of different fixatives and enzymatic-digestion procedures on the immunohistochemical visualization of type-I, -III and -IV collagen in paraffin-embedded normal human liver sections. None of the fixatives tested allowed the staining of these antigens without prior enzymatic digestion. The best results i.e. strong staining intensity and well-defined localization, were obtained when liver tissue was fixed in Bouin's fluid or in other solutions containing picric acid. Several other fixatives, including Carnoy's fluid, Lillie's AAF, 10% neutral formalin and 96% ethanol, gave unsatisfactory results. Pepsin was ineffective for unmasking type-I and -III collagen antigens, and was only partially effective for visualizing the type-IV collagen antigen. The best results were obtained when material fixed in Bouin's fluid was embedded in paraffin and digested with trypsin. Using this procedure, the results were comparable to those obtained in unfixed frozen sections with respect to the staining intensity, specificity and non-specific staining.

Collagen↗

African swine fever virus DNA: deletions and additions during adaptation to growth in monkey kidney cells.

Restriction enzyme cleavage maps for the fragments produced by Cla I, Sal I and Sma I have been constructed for African swine fever virus (ASFV) DNA grown in pig leukocytes (strain E70 L6) and after adaptation to growth in MS monkey kidney cells (strain E70MS14). The mapping data revealed that before adaptation to growth in MS cells, the size of the DNA from ASFV strain E70 L6 was l73 Kbp and after adaptation it was only l56 Kbp. The decrease in size was produced by deletions and additions mainly in the terminal regions of the genome. These genetic variations were located between 0.0 to 0.01 m.u. (Cla I-M1 fragment), 0.04 to 0.14 m.u. (Sma I-B1, Sal I-A1 fragments), 0.51 to 0.52 m.u. (Cla I-O fragment), 0.84 to 0.86 m.u. (Sma I-H1), 0.95 to 0.97 m.u. (Cla I-A1, Cla I-G1 fragments) and 0.99 to 1.0 m.u. (Cla I-G1) on viral genome of ASFV grown in pig leukocytes.

African Swine Fever Virus↗