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Biomedical subjects

J James

Publications and source records attributed to J James.

At least 127 records · Page 7Linked to original sources

Mineral content of rib bone in infant deaths.

The mineral content of rib bone in infants who died unexpectedly was similar to that among those who died after acute illnesses, and it was significantly associated with both crown to heel length and age. In those dying from chronic illnesses it was lower than in the other two groups.

Acute Disease↗

A scanning electron microscopic study of the common bile duct epithelium in the rabbit during experimental biliary tract obstruction.

Complete biliary obstruction was induced in rabbits by distal ligation of the common bile duct (CBD). The epithelial surface of the CBD was studied with scanning electron microscopy (SEM) at 1-6 days post-ligation. Concomitant biochemical assessments and pressure measurements in the CBD were performed. SEM of non-ligated CBD showed that the epithelium is arranged in folds and clefts, the latter displaying interdigitating cellular processes. At 2 days post-ligation, the epithelial clefts were focally distended showing marked dehiscence of the cellular processes with exposure of the subepithelial connective tissue layer. At 4-6 days post-ligation, extensive defects in the epithelium were observed, frequently with a sharp demarcation between intact epithelium and exposed connective tissue stroma.

Alkaline Phosphatase↗

Iron deficiency in inner city pre-school children: development of a general practice screening programme.

Iron deficiency in children has been associated with behavioural disorder and developmental delay. Screening for iron deficiency was offered to all 527 children aged between one and four years in an inner city practice. Half the children belong to an ethnic minority group, and there is widespread social deprivation in the area. Capillary haemoglobin concentration and mean corpuscular volume were estimated in 365 children (69%). Dietary history, birth weight and current weight were also recorded. Fifty-eight (16%) of the children were iron deficient as defined by a mean corpuscular volume of less than 75 fl and/or a haemoglobin concentration of less than 10.5 g dl(-1). All were hypochromic and among 23 tested all had serum ferritin levels below 10microg I(-1). Twenty-one children (5.8%) were anaemic (haemoglobin concentration less than 10.5 g dl(-1)). Anaemia was significantly more common among children who were currently underweight but was not related to weight at birth. Iron deficiency was significantly more prevalent in non-Caucasian children - 25.0% compared with 7.8% of Caucasian children. There was also a significant linear decrease in iron deficiency with increasing age. Sex, weight at birth, current weight, whether breast fed, age weaned or whether on a vegetarian diet were not significant factors in iron deficiency. Iron supplements were given to all the children with iron deficiency.In view of the high prevalence of iron deficiency, all children in the practice are now routinely offered screening for iron deficiency at the age of 14 months. The programme has been welcomed by all parents. It is suggested that screening for iron deficiency should be part of routine child surveillance.

Anemia, Hypochromic↗

Changes in the acinar distribution of some enzymes involved in carbohydrate metabolism in rat liver parenchyma after experimentally induced cholestasis.

Extrahepatic cholestasis induced by ligation and transsection of the common bile duct caused a change in the parenchyma/stroma relationship in rat liver. Two weeks after ligation, the periportal zones of the parenchyma were progressively invaded by expanding bile ductules with surrounding connective tissue diverging from the portal areas. Parenchymal disarray developed and small clumps of hepatocytes or isolated hepatocytes were scattered within the expanded portal areas. These cells showed normal activity of lactate, succinate and glutamate dehydrogenase and may, therefore, be considered to be functionally active. After cholestasis the remainder of the liver parenchyma showed adaptational changes with respect to glucose homeostasis, as demonstrated by histochemical means. Glycogen stores disappeared completely whereas glycogen phosphorylase activity increased about ten fold. The increased glycogen phosphorylase activity and glycogen depletion indicate a greater glycogenolytic capacity in liver parenchyma after bile duct ligation to maintain as far as possible a normal plasma glucose concentration. The parenchymal distribution pattern of glucose-6-phosphatase activity did not change significantly after bile duct ligation. The isolated hepatocytes within the expanded portal tracts showed a high activity of this enzyme whereas the pericentral parenchyma was only moderately active. The distribution patterns of glucose-6-phosphate dehydrogenase and lactate dehydrogenase activity in the liver parenchyma were also largely unchanged after bile duct ligation, but the histochemical reaction for glucose-6-phosphate dehydrogenase activity demonstrated infiltration of the remainder of the parenchyma by non-parenchymal cells, possibly Küpffer cells and leucocytes as part of an inflammatory reaction. Under normal conditions the mitochondrial enzymes succinate and glutamate dehydrogenase show an opposite heterogenous distribution pattern in liver parenchyma. Following cholestasis both enzymes became uniformly distributed. The underlying regulatory mechanism for these different changes in distribution patterns of enzyme activities is not yet understood.

Animals↗

Ultrastructural changes in the rat liver during Euro-Collins storage, compared with hypothermic in vitro ischemia.

The ultrastructural alterations in liver tissue induced by in vitro ischemia at 4 degrees C under conditions commonly used for transplantation (Euro-Collins perfused and stored liver tissue) have been compared with changes due to hypothermic in vitro ischemia in non-perfused liver. It was found that the process of cell deterioration in non-perfused liver occurred very slowly; signs of irreversible damage appeared in sinusoidal lining cells before hepatocytes (after 24 and 96 h, respectively). Liver perfused with, and stored in Euro-Collins solution showed acceleration of the ischemical damage in both types of cell (irreversible damage to sinusoidal lining cells after 12 h and to hepatocytes after 52 h), compared with non-perfused liver. These findings indicate that the safe period for storage of rat liver in Euro-Collins before damage to the microcirculatory system is less than 12 h. It might also be questioned whether Euro-Collins treatment is the optimal procedure for tissue preservation before liver transplantation.

Animals↗

Oral lichenoid reactions related to mercury sensitivity.

Lichen planus is a common disorder of unknown aetiology. It has been proposed that in some cases it represents a form of allergic reaction to the metals contained in dental amalgam, particularly mercury. Twenty-nine consecutive dentate patients who had lichen planus of the oral mucosa were patch-tested to the range of metals contained in dental amalgam. Ten out of 29 (34%) showed an allergic reaction to mercury and all of these patients had amalgams greater than 5 years old. The amalgams were poorly contoured and had corroded, resulting in continued release of mercury ions. Six patients had their amalgams replaced with composite or glass ionomer materials resulting in resolution of ulcerated lesions. In a follow-up of 3-24 months, one patient had a recurrence of ulcerated areas and another, despite resolution of the oral lesions had persistent discomfort.

Adult↗

Multiple granular cell tumors of the palate.

A report of a case of bilateral granular cell tumors of the soft palate is presented. This is an unusual location for the tumor and is the first report of bilateral tumors at this site.

Adult↗

Failure of post-bacteraemia delayed antibiotic prophylaxis of experimental rabbit endocarditis.

Twenty-one rabbits had a cannula placed in the left ventricle and 48 h later 1 ml of a culture of Streptococcus sanguis NCTC 7864 was injected into an ear vein. Six hours later, 400 mg/kg of amoxycillin was administered intramuscularly to 17 animals, the others acting as non-antibiotic treated controls. Two of the 17 rabbits died during the experimental period, and the cannula was incorrectly placed in another two. Five of the remaining 13 animals developed endocarditis. All controls developed endocarditis. Amoxycillin administered 6 h after an induced bacteraemia failed to prevent endocarditis in five (38%) of 13 rabbits.

Amoxicillin↗

DNA and nuclear protein measurement in isolated nuclei of human endometrium.

Feulgen-DNA and nuclear light green-protein measurements have been performed in isolated nuclei of normal (nonmalignant) and malignant human endometrial homogenates. The DNA content of the G0/G1 fraction of malignant endometrium showed much overlap with that of normal endometrium, or was slightly increased. Two of the 18 carcinomas were clearly aneuploid. No correlation was found between the histological grade and the DNA content. The tumors of clinical stage II and higher all had a higher DNA content than that of normal endometrium. The percentage of cells present in the proliferative fraction was higher in proliferative endometrium than in secretory and post-menopausal atrophic endometrium. For malignant endometrium, percentages were found comparable to that of normal endometrium or higher. No correlation was found with the histological grade. Tumors of stage II and higher had intermediate values compared to those of carcinomas below stage II. The nuclear protein/DNA ratio of malignant endometrium completely overlapped that of normal endometrium. However, for post-menopausal women, most values of the carcinomas exceeded that of normal, atrophic, endometrium. Within the tumor population, no correlation was found with the histological grade. Higher values were found with tumors of clinical stage II and higher.

Adult↗

DNA and nuclear protein measurement in columnar epithelial cells of human endometrium.

Propidium iodide DNA flow cytometry, Feulgen-DNA, and nuclear light green protein scanning cytometry were performed in columnar epithelial cells of normal, nonmalignant human endometrium and endometrial adenocarcinomas. Columnar cells were identified by immunohistochemical staining for cytokeratin 18, an intermediate filament protein specifically present in columnar cell epithelium. DNA measurements derived from flow and scanning cytometry showed comparable results. The DNA content of the G0/G1 fraction of the adenocarcinomas had a considerable overlap with that of normal endometrium, with that of the carcinomas shifted toward higher values. For the carcinomas, no correlation was found with the histological grade, with the exception of the adenosquamous carcinomas. Most of the clinical stage I tumors showed a DNA content in the normal diploid region. Three of the four carcinomas of clinical stage II and higher had an increased DNA content. For the carcinomas, the percentage of cells in the proliferative fraction, as determined from scanning cytometric derived DNA histograms, was comparable to that of normal endometrium, or higher. No correlation was found with the histological grade. Tumors of clinical stage II and higher had intermediate values compared to carcinomas of lower stages. The nuclear protein/DNA ratio of malignant endometrium completely overlapped that of normal endometrium. Within the tumor population, no correlation was found with the histological grade, with the exception of the adenosquamous carcinomas, and clinical stage. Based on the aforementioned parameters, no discrimination could be obtained between normal and malignant endometrium. However, when the DNA content of the G0/G1 fraction was combined with the coefficient of variation of the nuclear protein/DNA ratio, a clear discrimination could be obtained with only two false-positive cases.

Adenocarcinoma↗

Quantitative changes in the lysosomal vacuolar system of rat hepatocytes during short-term starvation. A morphometric analysis with special reference to macro- and microautophagy.

Ultrastructural morphometric analysis was used to study time-dependent variations in macro- and microautophagy in rat hepatocytes. Except during periods of short-term starvation for up to 24 h, animals were kept under standardized conditions of food intake. In hepatocytes of meal-fed rats the volume fraction of macroautophagic vacuoles is significantly higher at 23:00 h, i.e., immediately before food intake, compared to 11:00 h, i.e., 12 h following feeding. During fasting, macroautophagy drops to a low level. Microautophagic vacuoles in hepatocytes of meal-fed rats, sacrificed at 11:00 or 23:00 h respectively, do not show any significant quantitative differences. However, during 12 h of starvation, the volume fraction of microautophagic vacuoles rises significantly, whereas the numerical density remains constant. Subsequently, during the second 12-h period of fasting, the volume fraction of microautophagic vacuoles remains unchanged, but the numerical density increases. Over a period of 24 h of starvation the volume fraction of the total lysosomal system does not change significantly, whereas the numerical density rises. The time-dependent changes of the macroautophagic vacuolar system correlate with the circadian, food-related variations in the protein content of individual hepatocytes from meal-fed animals. The increase in volume fraction and thereafter in number of microautophagic vacuoles, as observed during starvation, coincides with a large decrease in protein content of individual hepatocytes.

Animals↗

Naphthol-yellow-S protein content of individual rat hepatocytes as related to food intake and short-term starvation.

With regard to the protein content, as analysed cytophotometrically, of hepatocytes from rats kept under a 12L 12D photoperiod (photophase 7:00-19:00), the following facts have been established: 1) Hepatocytes of different classes of ploidy all demonstrate, more or less equally, daily variations in protein content and also its reduction after 24-h fasting. 2) With computer analysis of data obtained at eight time points during a period of 24 h, a sinusoidal curve of the protein content of individual mononuclear tetraploid hepatocytes throughout the day could be demonstrated with a maximum at 6:20 and a minimum at 18:20. 3) Animals, fed with meals via a dispensing machine from 23:00 to 24:00 only, show a similar sinusoidal curve but with higher amplitude, and a virtually identical mean value as those fed ad libitum. The maximum was found at 10:40, revealing a time lag of 12 h after food intake, the minimum at 22:40. 4) Trained animals deprived of food during the standardized feeding time revealed a moderate reduction of their hepatocyte protein content in the first 6 h, then a 6-h period with a steep fall followed by a slower reduction. After 24 h, the mean hepatocyte protein mass had decreased to 72% of that at the commencement of fasting at 23:00.

Animals↗

Detection of metabolic changes in hepatocytes by quantitative cytochemistry.

Studies by means of quantitative histochemistry and cytochemistry have greatly contributed to the knowledge of metabolic changes in liver parenchymal cells. In the present paper recent work along this line is reviewed with emphasis on three topics, polyploidy as a source of metabolic heterogeneity, proteolysis in the regulation of hepatocyte cell mass and ischemic injury of hepatocytes. In all three fields, accuracy and precision of information obtained by quantitative histochemical means has been greatly enhanced by a thorough knowledge of the mechanisms of histochemical reactions obtained by fundamental work on matrix chemistry, and well-considered application of optical measuring tools and conditions of measurement. These are the principles put forward by van Duijn since the pioneer period of histochemistry and to whom this review is dedicated.

Alanine Transaminase↗

Histophotometric estimation of volume density of collagen as an indication of fibrosis in rat liver.

The development of fibrosis in the liver of 16 rats treated for 1, 2, 3 or 4 weeks with CCl4, has been followed with chemical hydroxyproline determination and histophotometric analysis of histological sections stained with Sirius Red F3BA in saturated aqueous picric acid. The readings were taken with a scanning and integrating microphotometer and corrected for picric acid absorbance as a measure for mean protein mass per unit area of the section. It appears that the integrated absorbance readings of Sirius Red absorbing material in the section show a highly significant correlation with the hydroxyproline determinations. It is concluded that picrosirius photometry can be used to give a measure of the volume density of collagen in sections. An advantage of the photometric assay is that measurements are taken on the basis of the microscopic image, so that it is also possible to estimate collagen density in a selected area, e.g. a tumour formation amidst normal tissue, or to exclude necrotic areas.

Animals↗