CORRELATION OF DIAMETERS OF SECRETORY GRANULES IN CLINICALLY NON-FUNCTIONING CHROMOPHOBE ADENOMAS OF THE PITUITARY WITH THOSE OF NORMAL THYROTROPHS

1975 ◽  
Vol 79 (3) ◽  
pp. 417-420 ◽  
Author(s):  
A. B. Gray ◽  
I. Doniach ◽  
P. N. Leigh
Keyword(s):  
Electron Micrographs ◽  
Secretory Granules ◽  
Close Correlation ◽  
Granule Size ◽  
Mean Diameter ◽  
Pituitary Glands ◽  
The Mean ◽  
20 Nm

ABSTRACT Diameters of secretory granules in thyrotrophs and in gonadotrophs were measured in electron micrographs of operation specimens of 4 pituitary glands and of the secretory granules in operation specimens of 10 clinically non-functioning chromophobe adenomas. The mean diameter of the thyrotroph granules was 137 ± 26 nm, of the gonadotrophs 204 ± 38 nm, of 9 of the adenomas 141 ± 20 nm and of the remaining adenoma 248 ± 67 nm. The significance of the close correlation in granule size in most of the adenomas with that of thyrotrophin granules is discussed briefly.

ANALYSIS OF DIAMETERS OF HUMAN PITUITARY HORMONE SECRETORY GRANULES

1977 ◽  
Vol 85 (2) ◽  
pp. 249-255 ◽  
Author(s):  
A. B. Gray
Keyword(s):  
Electron Micrographs ◽  
Anterior Pituitary ◽  
Secretory Granules ◽  
Pituitary Hormone ◽  
Human Pituitary ◽  
Pituitary Glands ◽  
The Mean ◽  
Human Anterior Pituitary

ABSTRACT Measurements were made on electron micrographs of six human anterior pituitary glands of the maximal diameters of secretory granules in 130 cells, average 91 granules per cell. This was done in an attempt to classify the various hormone types solely by differences in the mean diameters of the secretory granules. The range of diameters in nanometers could be segregated into six subgroups of the following suggested functions: 135.5 ± 13.6 TSH, 181.6 ± 9.3 LH, 226.0 ± 19.4 FSH, 356.8 ± 30.5 ACTH/MSH, 452.9 ± 23.8 GH, 559.9 ± 38.0 prolactin.

Changes in the granule population of gonadotrophs of hypogonadal (hpg) and normal female mice associated with the priming effect of LH-releasing hormone in vitro

1986 ◽  
Vol 109 (1) ◽  
pp. 35-NP ◽  
Author(s):  
C. E. Lewis ◽  
J. F. Morris ◽  
G. Fink ◽  
M. Johnson
Keyword(s):  
Priming Effect ◽  
Marginal Zone ◽  
Secretory Granules ◽  
Initial Exposure ◽  
Releasing Hormone ◽  
Female Mice ◽  
Mean Diameter ◽  
Lh Release ◽  
The Mean ◽  
Lh Releasing Hormone

ABSTRACT Changes in the size and position of secretory granules in pituitary gonadotrophs have been studied in relationship to LH release and self-priming induced by LH-releasing hormone (LHRH) in pituitary glands from normal and hypogonadal (hpg) female mice. Hemipituitary glands were preincubated and then incubated for either 1 or 2 h in the absence or presence of LHRH (8·5 nmol/l). The glands were either processed for ultrastructural morphometry or homogenized for the determination of pituitary LH content. Morphometry was carried out on gonadotrophs identified by immunocytochemistry for LHβ using the thin/semi-thin section method. Pituitary LH content and the amount of LH released were determined by radioimmunoassay. The amount of LH released in response to the first and second hours of incubation with LHRH were similar in hpg and normal mice with a clear priming effect (three- to fourfold increase in pituitary responsiveness to LHRH) occurring in both strains. Despite a substantially reduced total number of granules (and amount of LH) in unstimulated hpg gonadotrophs, the number of granules in the outer 500 nm marginal zone of the cells was similar to that in normal mice. This could explain the similar amount of LH released from normal and hpg glands by the first LHRH challenge. The initial exposure to LHRH was also associated with a marked translocation of secretory granules from the central to the outer marginal region of cytoplasm subjacent to the gonadotroph plasmalemma, such that in 'primed' glands 60% of granules were found in this marginal zone compared with 40% (hpg) or 33% (normal) in unstimulated glands. The mean diameter of granules in the marginal zone was significantly less than that of granules in the central zone of the gonadotrophs of unstimulated glands from both normal and hpg animals. Exposure to LHRH for 1 h was associated with an increase in the number of small granules in the marginal zone and a significant decrease in the mean diameter of the gonadotroph granule population as a whole. After the primed release of LH, increased proportions of granules were still located in the marginal zone of gonadotrophs, indicating that granule migration continued during the second hour of exposure to LHRH in which primed release occurred. The primed release was associated with a detectable reduction in both the LH and granule content of gonadotrophs in normal, but not hpg glands. The ultrastructural correlates of LH release and LHRH priming were similar in the two strains of mice, and therefore in mice neither the releasing nor the priming effect of LHRH depends upon previous exposure of the pituitary gland to LHRH or ovarian factors. The priming effect was associated with a marked shift of granules towards the plasmalemma and a decrease in granule size which most likely resulted from increased post-translational processing within secretory granules. J. Endocr. (1986) 109, 35–44

Pituitary Follicular Cells: Their Origin, Possible Function and Fate

1974 ◽  
Vol 32 ◽  
pp. 34-35
Author(s):  
E. Horvath ◽  
K. Kovacs ◽  
G. Penz ◽  
C. Ezrin
Keyword(s):  
Fine Structure ◽  
Secretory Granules ◽  
Follicular Cells ◽  
Human Pituitary ◽  
Rat Pituitary ◽  
Pituitary Glands ◽  
Junctional Complexes

Follicular structures, in the rat pituitary, composed of cells joined by junctional complexes and possessing few organelles and few, if any, secretory granules, were first described by Farquhar in 1957. Cells of the same description have since been observed in several species including man. The importance of these cells, however, remains obscure. While studying human pituitary glands, we have observed wide variations in the fine structure of follicular cells which may lead to a better understanding of their morphogenesis and significance.

Monoamine Oxidase and Other Mitochondrial Enzymes in Density Subpopulations of Human Platelets

1988 ◽  
Vol 59 (01) ◽  
pp. 029-033 ◽  
Author(s):  
K G Chamberlain ◽  
D G Penington
Keyword(s):  
Monoamine Oxidase ◽  
Protein Concentration ◽  
Close Correlation ◽  
Human Platelets ◽  
Mitochondrial Enzymes ◽  
Density Fractions ◽  
Percoll Gradients ◽  
Normal Human ◽  
The Mean ◽  
Very High

SummaryNormal human platelets have been separated according to density on continuous Percoll gradients and the platelet distribution divided into five fractions containing approximately equal numbers of platelets. The mean volumes and protein contents of the platelets in each fraction were found to correlate positively with density while the protein concentration did not differ significantly between the fractions. Four mitochondrial enzymes (monoamine oxidase, glutamate dehydrogenase, cytochrome oxidase and NADP-dependent isocitrate dehydrogenase) were assayed and their activities per unit volume were found to increase in a very similar monotonie fashion with platelet density. When MAO and GDH were assayed on the same set of density fractions the correlation between the two activities was very high (r = 0.94–1.00, p <0.001) and a similar close correlation was found between MAO and ICDH. The results support the hypothesis that high density platelets either have a higher concentration of mitochondria or have larger mitochondria than low density platelets.

THE EXTRACTION OF PROLACTIN FROM HUMAN PITUITARY GLANDS

1965 ◽  
Vol 49 (1) ◽  
pp. 1-16 ◽  
Author(s):  
M. Apostolakis
Keyword(s):  
Growth Hormone ◽  
Pituitary Gland ◽  
List Type ◽  
Distilled Water ◽  
Hormone Activity ◽  
Isoelectric Precipitation ◽  
Human Pituitary ◽  
Pituitary Glands ◽  
Prolactin Content ◽  
The Mean

ABSTRACT A method for the extraction of prolactin from human pituitary glands is described. It is based on acetone drying, distilled water extraction, acetone and isoelectric precipitation. Two main products are obtained: Fraction R8 with a mean prolactin activity of 12.2 IU/mg and fraction U8 with a mean prolactin activity of 8.6 IU/mg. The former fraction does not contain any significant gonadotrophin activity and the latter contains on an average 50 HMG U/mg. In both cases contamination with ACTH and MSH is minimal. The growth hormone activity of both these fractions is low. It is postulated that in man too, prolactin and growth hormone are two distinct hormones. A total of 1250 human pituitary glands have been processed by this method. The mean prolactin content per pituitary gland has been found to be 73 IU.

Non-isothermal crystallization behavior of spinel crystals in FeO-SiO2-TiO2-V2O3-Cr2O3 slag

2018 ◽  
Vol 116 (1) ◽  
pp. 110
Author(s):  
Lixiong Shao ◽  
Jiang Diao ◽  
Wang Zhou ◽  
Tao Zhang ◽  
Bing Xie
Keyword(s):  
Cooling Rate ◽  
Crystallization Behavior ◽  
Crystal Size ◽  
Growth Mechanisms ◽  
Vanadium Slag ◽  
Growth Behaviour ◽  
Temperature Range ◽  
Chromium Spinel ◽  
Mean Diameter ◽  
The Mean

The growth behaviour of spinel crystals in vanadium slag with high Cr2O3 content was investigated and clarified by statistical analyses based on the Crystal Size Distribution (CSD) theory. The results indicate that low cooling rate and Cr2O3 content benefit the growth of spinel crystals. The chromium spinel crystals firstly precipitated and then acted as the heterogeneous nuclei of vanadium and titanium spinel crystals. The growth mechanisms of the spinel crystals at the cooling rate of 5 K/min consist two regimes: firstly, nucleation control in the temperature range of 1873 to 1773 K, in which the shapes of CSD curves are asymptotic; secondly, surface and supply control within the temperature range of 1773 to 1473 K, in which the shapes of CSD curves are lognormal. The mean diameter of spinel crystals increases from 3.97 to 52.21 µm with the decrease of temperature from 1873 to 1473 K.

scholarly journals Bark proportion of Scots pine industrial wood

2021 ◽  
Author(s):  
Ferréol Berendt ◽  
Erik Pegel ◽  
Lubomir Blasko ◽  
Tobias Cremer
Keyword(s):  
Supply Chain ◽  
Scots Pine ◽  
Bark Thickness ◽  
Wood Supply ◽  
Volume Proportion ◽  
Bark Damage ◽  
Mass Proportion ◽  
Mean Diameter ◽  
The Mean

AbstractBark characteristics are not only used in the forest-wood supply chain, for example to calculate standing volumes, but also to transform wood volumes and masses. In this study, bark thickness, bark volume and bark mass were analyzed on the basis of 150 Scots pine discs, with a mean diameter of 13 cm. The mean double bark thickness was 3.02 mm, the mean bark volume proportion was 5.6% and mean bark mass proportion was 3.3%. Bark proportions were significantly affected by the log-specific variables ‘diameter over bark’, ‘proportion of bark damage’ and ‘double bark thickness’.

CONTROLLABLE CHEMICAL VAPOR DEPOSITION SYNTHESIS OF SINGLE-WALL CARBON NANOTUBES USING MIST FLOW METHOD

NANO ◽  
2012 ◽  
Vol 07 (06) ◽  
pp. 1250045 ◽  
Author(s):  
YUN SUN ◽  
RYO KITAURA ◽  
TAKUYA NAKAYAMA ◽  
YASUMITSU MIYATA ◽  
HISANORI SHINOHARA
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Single Wall Carbon Nanotubes ◽  
Flow Method ◽  
Mist Flow ◽  
Mean Diameter ◽  
The Mean

The influences of synthesis parameters on the mean diameter and diameter distribution of as-grown single-wall carbon nanotubes (SWCNTs) with chemical vapor deposition (CVD) using the mist flow method have been investigated in detail with Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). We found that CVD reaction temperature and flow rate play an essential role in controlling the mean diameter and the quality of as-grown SWCNTs. Furthermore, we found that the carbon supply kinetics can be a dominant factor to determine the diameter of as-grown SWCNTs in the present mist flow method. Under a different combination of various parameters, the mean diameter of SWCNTs can be varied from 0.9 nm to 1.5 nm controllably.

Initial Clinical Experience with Percutaneous Atherectomy in the Infragenicular Arteries

2003 ◽  
Vol 10 (5) ◽  
pp. 987-993 ◽  
Author(s):  
Thomas Zeller ◽  
Ulrich Frank ◽  
Karlheinz Bürgelin ◽  
Uwe Schwarzwälder ◽  
Peter-Christian Flügel ◽  
...  
Keyword(s):  
Balloon Angioplasty ◽  
Ankle Brachial Index ◽  
Peroneal Artery ◽  
Lesion Length ◽  
Anterior Tibial Artery ◽  
Tibial Artery ◽  
Below The Knee ◽  
Directional Atherectomy ◽  
Mean Diameter ◽  
The Mean

Purpose: To evaluate the efficacy and safety of a new atherectomy device for the treatment of infragenicular lesions in arteries with a reference diameter of at least 2.5 mm. Methods: Twenty-seven below-the-knee lesions in 17 patients (12 men; mean age 69±12 years) with chronic peripheral arterial occlusive disease were treated with directional atherectomy. The target lesion was in the popliteal artery (segment 3) in 2 (7%) cases, the tibioperoneal trunk in 12 (44%), the peroneal artery in 8 (30%), the anterior tibial artery in 2 (7%), and the posterior tibial artery in 3 (11%). Six (22%) of the lesions were in-stent stenoses. The mean diameter stenosis was 87%±9%, and the mean lesion length was 34±24 mm. Results: All but 2 (7%) of the lesions could be treated successfully (residual stenosis <30%) with the atherectomy catheter (93% technical success) using an average of 5±2 (range 1–10) passes of the device. Six lesions (22%) were treated after predilation and 21 (78%) with primary atherectomy. In 8 (30%) lesions, additional balloon angioplasty was performed. The 2 failures were in heavily calcified lesions through which the device could not pass despite predilation. The mean diameter stenosis after atherectomy was 14%±22% (range 0%–90%); after additional balloon angioplasty, the mean residual stenoses reduced to 12%±21% (range 0%–100%). One (6%) of the 2 patients who failed atherectomy sustained a thrombotic occlusion of the target vessel. This complication was treated successfully with local lysis, but the vessel reoccluded 3 days later; a stent was implanted. The mean ankle-brachial index increased from 0.50±0.27 to 0.86±0.40 before discharge. Conclusions: Below-the-knee native vessel lesions and in-stent restenoses with a diameter of at least 2.5 mm can be treated successfully and safely with this new atherectomy catheter. Additional balloon angioplasty was necessary in only a few cases.

Mean Diameters in Parallel-Flow and Counter-Flow Aerosol Systems

1976 ◽  
Vol 98 (2) ◽  
pp. 297-302 ◽  
Author(s):  
K. G. T. Hollands ◽  
K. C. Goel
Keyword(s):  
Mass Transfer ◽  
Continuous Phase ◽  
General Concept ◽  
Parallel Flow ◽  
General Definition ◽  
Single Pair ◽  
Counter Flow ◽  
Mean Diameter ◽  
The Mean ◽  
Definition Of

The general concept of the mean diameter of the disperse phase of an aerosol system, first introduced by Mugele and Evans in 1951, has proven to be a very useful one. In this concept, the proper mean diameter, xp,q, is characterized by a single pair of indices, p and q, which are dependent on the actual type of aerosol system under consideration. This paper re-examines the validity of this concept of mean diameter in heat and mass transfer aerosol systems. The concept is found to be applicable only under a very narrow range of conditions. Attention is then given to a more general definition of a mean diameter, applicable to aerosol heat or mass exchangers. Analyses of these devices shows that the more general mean diameter is a function of the capacity rate ratio, R, and effectiveness of the heat exchanger, ε. Solutions to the governing equations have permitted the mean diameter to be presented graphically as a function of these variables. These solutions are given for two types of particle size distributions, the Rosin-Rammler and the log-probability, and for both parallel-flow and counter-flow heat exchangers. The solutions are, however, restricted to cases where the resistance to heat or mass transfer lies exclusively in the continuous phase.

Sign in / Sign up

Export Citation Format

Share Document