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Biomedical subjects

A Haddad

Publications and source records attributed to A Haddad.

At least 163 records · Page 9Linked to original sources
PubMed1985

[Detection of anterior interventricular involvement after primary posterior wall infarct].

Forty-five patients (average age 53.3 +/- 9.4 years) underwent exercise stress testing coupled with exercise myocardial scintigraphy and right heart catheterisation on exercise during the 3rd week after primary posterior wall infarction. Coronary angiography and ventriculography were carried out 24 to 48 hours later. Significant (greater than or equal to 75%) left anterior descending disease was present in 9 patients (Group I) and absent in 36 patients (Group II). Tolerance of maximal exercise stress testing was good in all patients. The results were uninterpretable in on third of the cases because the theoretical maximal heart rate was not attained. No significant difference was noted between groups I and II with respect to: mean age, percentage of theoretical maximal heart rate attained, mean pulmonary capillary pressures at rest and during exercise, basal and exercise cardiac index, end diastolic index and angiographic left ventricular ejection fraction. The sensitivity and specificity for the detection of LAD disease were 80% and 84% for the exercise stress testing (n = 30), 44% and 75% for exercise right heart catheterisation (n = 30), 60% and 92% for exercise myocardial scintigraphy (n = 30), 100% and 75% for combined exercise stress testing and myocardial scintigraphy (n = 30) and 78% and 64% for combined exercise stress testing and myocardial scintigraphy and exercise right heart catheterisation (n = 45). These results show that in patients capable of performing maximal exercise stress tests, the best method of early detection of significant LAD disease after primary posterior infarction was combined exercise stress testing and exercise myocardial scintigraphy. These investigations are useful for the selection of candidates for coronary angiography.

Adult↗
PubMed1985

Angioedema of the head and neck.

A group of 143 patients with angioedema was reviewed. Women in their third and fourth decades were most commonly affected. Head and neck involvement was found in 94% of cases and this was the only anatomical site in 24%. Twenty-one patients had swelling of the oropharynx while four presented with laryngeal edema. A diagnosis of hereditary angioedema (HAE) was confirmed in one case. Asthma, allergic rhinitis, and drug sensitivity were significantly associated, while smaller numbers of patients had underlying vasculitis or active ongoing infection. The pathophysiology and management of angioedema are discussed.

Adolescent↗
PubMed1984

Motility of the terminal ileum and ileocecal sphincter in healthy humans.

Factors controlling the transit of contents between the ileum and cecum should be important determinants of intestinal function; however, the dynamics of the ileocecal region remain largely unexplored in healthy humans. Accordingly, prolonged recordings of intraluminal pressure were obtained from the distal ileum, across the ileocecal sphincter, and from the proximal colon of healthy adults. In one set of studies, 16 subjects each contributed 6 h of basal, fasting recordings; in 2 of the 16, postprandial patterns were also recorded. In a second set, 6 fasting subjects were studied for a total of 120 h. Less than 10% of interdigestive cycles (migrating motor complexes) reached the ileocecal sphincter. The remainder faded out and merged into an active, apparently random pattern of pressure waves that became more intense closer to the sphincter. Discrete, short bursts of phasic pressures migrated rapidly for long distances in the distal ileum and a unique peristaltic wave also migrated rapidly, though infrequently, through the region. Tonic pressures were recorded across the ileocecal sphincter but were present only during the passage of phasic pressure waves; basal tone was minimal. We believe these are the first prolonged observations of motility from the ileocecal sphincter of healthy humans. These descriptions provide insights into and a basis for further studies of a largely unexplored area of the human bowel.

Action Potentials↗
PubMed1984

[Coxarthrosis].

Explore the source record for details and available documents.

Aged↗
PubMed1983

Synthesis of membrane and secretory glycoproteins by the acinar pancreatic cells as visualized by radioautography.

Young rats were injected with 3H-fucose and killed at 10 min, 1, 4 and 24 h thereafter. Samples of the pancreas were processed for light- and electron-microscopic radioautography and then analyzed quantitatively. Fucose label was taken up in the supranuclear region of acinar pancreatic cells that were maximally labeled at 1 h after injection. Between 1 and 24 h after injection there was a very marked decrease in the concentration of label in the pancreatic acini. Radioautography at the ultrastructural level demonstrated that the earliest time interval the silver grains indicating the sites of newly synthesized glycoproteins were predominantly observed over the Golgi apparatus of the acinar cells. The quantitative analysis indicated that condensing vacuoles were labeled from 10 min to 4 h after injection. At 1 h the concentration of label in the Golgi apparatus was greatly diminished while it was significantly higher in the secretory (zymogen) granules. At this interval the secretion product visualized in the lumen of the acini and of the ducts was found to be labeled. At 4 h both the zymogen granules and the plasma membrane were significantly labeled. Further analysis carried out on the zymogen granules indicated that fucose-labeled glycoproteins were located in the granule membrane as well as in the granule content. In conclusion, 3H-fucose is added to glycoproteins in the Golgi apparatus of the acinar cells. Then, labeled glycoproteins are collected within condensing vacuoles and zymogen granules and released into the acinar lumen as secretion products. This latter event, which almost certainly is a consequence of exocytosis, may also account for the addition of granule-membrane glycoproteins to the plasma membrane.

Animals↗
PubMed1982

Glycoprotein synthesis and migration in beta cells of the islets of Langerhans as shown by quantitative light- and electron-microscopic radioautography.

L-3H-fucose was injected intravenously into rats that were killed from 10 min to 7 days after isotope administration. Semi-thin and thin sections of the islets of Langerhans were processed for light- and electron-microscopic radioautography, respectively, and analyzed quantitatively. L-3H-fucose was incorporated into newly synthesized glycoproteins in the Golgi apparatus of the beta cells and subsequently labeled glycoproteins migrated to secretory granules and plasma membrane. Therefore, some of the glycoproteins synthesized by the beta cells of the islets of Langerhans are destined for the renewal of plasma membrane. Although the labeling of the secretory granules was clearly demonstrated, it was not possible to decide if the newly formed glycoproteins are incorporated into the content or into the membrane of the granule. Thus, the fate as well as the function of secretory-granule glycoproteins could not be determined precisely. Several hypothesis concerning the presence of glycoproteins in the secretory granules in relation with insulin metabolism are considered.

Animals↗
PubMed1980

Glycoprotein secretion in the hypothalamo-neurohypophyseal system of the rat.

Although the secretory products of the hypothalamo-neurohypophyseal system are not glycoproteins, synthesis and migration of these macromolecules occur within its secretory neurons. After being labeled with 3H-fucose in the Golgi apparatus, newly synthesized glycoproteins migrate to secretion granules, lysosomes and the plasma membrane of the secretory neurons, as demonstrated by quantitative electron-microscopic radioautography. Secretion granules bearing newly synthesized glycoproteins migrate to the pars nervosa, the labeling pattern of which was studied in rats killed from 4 h to 14 days after the isotope injection. Most of the silver grains were observed to overly the secretory axons. Labeling of pituicytes was negligible and the number of silver grains over the perivascular spaces was about 10% of the total at certain postinjection intervals. In the secretory axons, most of the silver grains over the different portions of the secretory axons changed with time. At the longer intervals, the percentage of silver grains increased over the nerve swellings (including Herring bodies) and decreased concomitantly in the undilated portions of the axons and in the nerve endings. This labeling pattern conforms with observations of the secretion products. Water deprivation increased the release of neurosecretion as well as glycoproteins from the pars nervosa. However, glycoproteins inside the Herring bodies were not easily releasible. There was a parallel decrease in the amount of secretion granules and 3H-fucose-labeled glycoproteins indicating that the glycoproteins are predominantly a constituent of the granule content. Some newly synthesized glycoproteins were probably also used in the renewal of the axonal membrane. The labeling of smooth vesicles in nerve endings was discussed. In conclusion, most of the glycoproteins synthesized in the perikarion of the hypothalmic secretory neurons migrate inside secretion graules along the axon to the pars nervosa where they are secreted.

Animals↗
PubMed1979

Incorporation of L-(3H)-fucose into glycoproteins of the adrenal gland of mice. Light microscope radioautographic study on semi-thin sections.

To study the biosynthesis and intracellular migration of glycoproteins in the adrenal gland, adult mice were injected intravenously with L-(3H)-fucose and killed from 10 min to 14 days after injection. Semi-thin sections of the adrenal glands were then processed for radioautography. Incorporation of labeled fucose occurred in the steroid-secreting cells of the three zones of the cortex as well as in the adrenalin (A) and noradrenalin (NA) cells of the medulla. At short intervals after injection, the main site of incorporation was the paranuclear region of the cells, suggesting uptake by the Golgi apparatus. Subsequently, labeled glycoproteins migrated from the paranuclear region to other cell sites. The labeling pattern observed in the adrenocortical parenchyme strongly suggests that the glycoproteins are transferred to lysosomes, lipofuscin granules and the cell coat (glycocalyx). Counts of silver grains clearly indicate that these glycoproteins undergo renewal. The qualitative and quantitative analysis of the radioautographs also suggest that glycoproteins, acting as intracellular carriers of steroids, may be released to the extracellular environment together with the hormones. Most of the glycoproteins synthesized by the A and NA cells of the adrenal medulla seem to be transferred to secretion granules in which they may play some role in the cytophysiology of these structures. It is likely that glycoproteins are released from the cells during exocytosis of secretory granules.

Adrenal Cortex↗
PubMed1978

Radioautographic and biochemical studies of secretion of venom protein in the South American rattlesnake Crotalus durissus terrificus.

Protein secretion was investigated in the main venom gland of the South American rattlesnake, using radioautographic and biochemical techniques after a single intracardiac injection of L-(3,5-3H)tyrosine. All the snakes were injected at the fourth day of the secretory cycle and killed at 1/2, 1, 2, 4, 8 and 24 hours after injection. Most of the radioactive amino acid is cleared from the blood stream up to four hours after injection. On the other hand the specific activity (c.p.m./mg of protein) of the intracellular proteins reaches a peak at the 4-hour time interval decreasing afterwards. There was a good correlation between the values of the specific activity of the intracellular proteins and those of the silver grain density over the secretory cells at the several time intervals after the injection of 3H-tyrosine. The results of the quantitative analysis carried out in light- and electron-microscope radioautographs led to the conclusion that venom proteins are synthesized in the rough endoplasmic reticulum of the secretory cells, transferred to the Golgi apparatus from where they are carried to the secretory tobule lumen by the secretion granules. The fact that the values of the relative concentration of the radioactivity of he intracisternal granules double at the last three time intervals, strongly suggests that these structures are formed by the aggregation of the amorphous material present inside the cisternae of the rough endoplasmic reticulum.

Animals↗
PubMed1977

Glycoprotein secretion in the mouse submandibular gland as revealed by radioautography after L-3H-fucose injection.

Glycoprotein secretion in the mouse submandibular gland was investigated by light microscope radioautography of semi-thin sections after the administration of L-3H-fucose. The incorporation of the precursor in the acini was negligible. 3H-fucose was taken up in the paranuclear region of the cells lining the intercalated, secretory, striated and excretory ducts. This labeling pattern was interpredted as addition of the precursor to glycoproteins within the Golgi apparatus. Incoropration in the intercalated duct was restricted to the cells with fine cytoplasmic granules. The glycoproteins synthesized by the intercalated and secretory ducts were transported to the saliva by the secretion granules. It is assumed that the glycoproteins synthesized in the striated and excretory ducts are plasma membrane glycoproteins which seem to renew continuously. Quantitation of the radioautographs supplied data concerning the incorporation of 3H-fucose into newly synthesized glycoproteins as well as the renewal of the labeled macromolecules in each duct.

Animals↗
PubMed1977

Radioautographic study of glycoprotein biosynthesis and renewal in the ovarian follicles of mice and the origin of the zona pellucida.

L-fucose-3H was injected intravenously into mice which were killed at several time intervals after injection and semi-thin sections of their ovaries were processed for radioautography and analysed quantitatively; At the same time the specific activity of serum glycoproteins was determined. Glycoprotein biosynthesis was demonstrated in the oocytes, granulosa and stromal cells. The silver grain density of the follicular fluid in large follicles reached a peak at 4 h, remained high at 8 h after injection and decreased steadily at the subsequent intervals. It was demonstrated that the labeling pattern of the follicular fluid depends on the secretory activity of the granulosa cells and also on the specific activity of serum glycoproteins. The collapsed zonae pellucidae which represent the highest degree of follicular atresia are able to take up glycoprotein macromolecules. Based on this finding and also on the labeling pattern of the large follicles it was shown that there is very little synthesis of specific glycoproteins for the zona pellucida in large follicles. A more specific labeling of the zona pellucida occurred in the medium follicles. Following the growth of these follicles having a previously labeled zona pellucida, it was demonstrated that this extracellular structure is secreted by the oocyte.

Animals↗
PubMed1977

Light microscope radioautographic study of glycoprotein secretion in the hypothalamic-neurohypophysial system of the rat, after L-fucose-3H injection.

Fucose-3H was injected into the cerebral ventricle of rats that were killed at several time intervals after injection. Semi-thin sections of the supraoptic nucleus and neurohypophysis were processed for radioautography and analysed quantitatively. Silver grains indicating the site of fucoselabeled glycoproteins were first located at the perinuclear region of the secretory neurons. The highest silver-grain density in these cells was observed at 2 h after injection , declining afterwards. Silver grains over the neurohypophysis were observed from 2 h on, reached a peak at 1 day after injection and decreased in the subsequent time intervals. The distributions of the silver grains over the neurohypophysis fitted Poissonian distributions and these were shown to be heterogeneous at the several time intervals. Pituicytes were not labeled. The percentage of silver grains over the Herring bodies increased with time. In rats deprived of water after fucose-3H injection there was a great increase in the release of labeled glycoproteins from the neurohypophysis. These results indicate that the glycoproteins synthesized by the secretory neurons of the hypothalamic nuclei are secreted in the neurohypophysis.

Animals↗
PubMed1977

Formation and turnover of plasma membrane glycoproteins in kidney tubules of young rats and adult mice, as shown by radioautography after an injection of 3H-fucose.

The formation and turnover of the glycoproteins of the plasma membrane have been investigated by quantitative radioautography in the kidney tubules of young rats and adult mice killed at various time intervals after an intravenous injection of 3H-fucose. In young (40 g) rats killed five to ten minutes after the injection, radioautographs of distal tubule cells show that the Golgi apparatus contained about 85% of the cell label. By 30 hours, only 8% of the label remained in this organnele, whereas 67% was in the plasma membrane, indicating that most of the label had migrated from Golgi apparatus to this membrane. Similarly, in proximal tubule cells, about 82% of the label was initially in the Golgi apparatus, but less than 2% remained at 30 hours, at which time 78% was in the plasma membrane. In the latter cells, the apical tubules and vacuoles became heavily labeled before the apical microvilli did and, therefore, may be involved in the transit of label from the Golgi apparatus to the microvillous membrane. The results are interpreted to mean that, in kidney tubule cells, the Golgi apparatus is the site of a continuous incorporation of fucose into glycoproteins and that these migrate to the plasma membrane. In fully formed cells, such a conclusion would imply a continuous turnover of plasma membrane glycoproteins. However, in the rapidly growing kidney of young rats many new cells are added daily, the growth of which might involve net addition as well as turnover of glycoproteins. Accordingly, the experiment has been repeated in adult mice, in which the cells are assumed to be fully formed. Furthermore, since turnover implies eventual decrease of incorporated label, some of the animals have been killed at longer intervals, up to 27 days after injection. In these adult mice, as in young rats, prompt Golgi uptake and subsequent migration of label to the plasma membrane were observed in distal and proximal tubules cells. With time the label content of the plasma membrane decreased gradually, and by 27 days had virtually disappeared. From grain counts, it is concluded that the mean half-life of glycoproteins in the apical membrane of distal tubule cells is about two days, whereas in both the apical and basal membranes of proximal tubule cells, it is slightly over three days.

Age Factors↗