scholarly journals Long-term administration of vitamin A and the process of spermatogenesis

1999 ◽  
Vol 5 (1) ◽  
pp. 123-129
Keyword(s):  
Electron Microscopy ◽  
Retinoic Acid ◽  
Leydig Cells ◽  
Light And Electron Microscopy ◽  
Ultrastructural Changes ◽  
Retinol Acetate ◽  
Term Administration ◽  
Stopping Treatment ◽  
Prevention Of Cancer

The effect of retinoids on spermatogenesis in adult male gerbils [Gerbillus cheesemani]was studied using light and electron microscopy. Treatment with either 13-cis-retinoic acid or retinol acetate was given for 6 weeks and their effects were compared with controls. It was found that 13-cis-retinoic acid induced almost complete cessation of spermatogenesis and produced alterations in the cytoplasm of Leydig cells. No differences were seen in the testis of animals treated with retinol acetate compared with controls using light microscopy but it appeared to produce noticeable ultrastructural changes in Leydig cells. The changes observed were reversed 12 weeks after stopping treatment. Caution should be exercised regarding the use of dietary retinoids in the prevention of cancer

Testicular oxytocin: effects of intratesticular oxytocin in the rat

1991 ◽  
Vol 130 (2) ◽  
pp. 231-NP ◽  
Author(s):  
H. D. Nicholson ◽  
S. E. F. Guldenaar ◽  
G. J. Boer ◽  
B. T. Pickering
Keyword(s):  
Leydig Cells ◽  
Light And Electron Microscopy ◽  
Male Rats ◽  
Plasma Testosterone ◽  
Epididymal Sperm ◽  
Long Term Effects ◽  
Sperm Counts ◽  
Term Administration

ABSTRACT The long-term effects of oxytocin administration on the testis were studied using intratesticular implants. Adult male rats had an Accurel device containing 20 μg oxytocin (releasing approximately 200 ng/day) implanted into the parenchyma of each testis; control animals received empty devices. The animals were killed at weekly intervals for 4 weeks. Some animals were perfused and the testes processed for light and electron microscopy. Blood was collected from the remaining animals for the measurement of testosterone, dihydrotestosterone, LH, FSH and oxytocin; epididymal sperm counts were measured and the testes were extracted and radioimmunoassayed for testosterone, dihydrotestosterone and oxytocin. Long-term administration of oxytocin resulted in a significant reduction in testicular and plasma testosterone levels throughout the 4-week period examined and, after 14 days of treatment, lipid droplets were seen in the Leydig cells of treated but not control animals. Concentrations of dihydrotestosterone in the plasma and testes of the oxytocin-treated animals, however, were significantly elevated after 7 and 14 days and at no time fell below control values. Plasma FSH levels were also lower in the oxytocin-treated animals. Intratesticular oxytocin treatment did not affect LH or oxytocin concentrations in the plasma, epididymal sperm counts or the number of Leydig cells in the testis. Empty Accurel devices had no effect on testicular morphology. This study provides the first evidence that oxytocin in vivo can modify steroidogenesis in the testis. Journal of Endocrinology (1991) 130, 231–238

A Case of Gastric Cancer in Which Long-Term Administration of 5′-Deoxy-5-Fluorouridine Proved Effective

1989 ◽  
Vol 17 (2) ◽  
pp. 179-184
Author(s):  
T. Koda ◽  
T. Kurahori ◽  
N. Iwao ◽  
S. Sumi ◽  
T. Sonoda ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Adverse Reactions ◽  
Substantial Improvement ◽  
Term Treatment ◽  
Borrmann Type ◽  
Long Term Treatment ◽  
Term Administration ◽  
Stopping Treatment ◽  
Lesser Curvature

A patient diagnosed with Borrmann type 4 gastric cancer (mucinous adenocarcinoma), who had refused surgery, was treated by oral administration of 1200 mg/day 5′-deoxy-5-fluorouridine for about 23 weeks. This resulted in substantial improvement of her condition, i.e. the tumour almost completely disappeared, distensibility improved between the central region of the corpus ventriculi and the angulus, and only small protrusions remained on the anterior and posterior walls and the pars pylorica of the lesser curvature. Mild anorexia and diarrhoea were noted as adverse reactions although these symptoms subsided by reducing the dose or temporarily stopping treatment, thereby allowing long-term treatment. Long-term use of 5′-deoxy-5-fluorouridine proved temporarily effective in this patient. The patient died about 3 years and 7 months after starting therapy. Examination showed that the cancer had been mainly in the stomach and that it had metastasized to the colon and pancreas. The liver was free of metastasis.

Maintenance of differentiated sheep thyroid cells in primary culture for three months

1984 ◽  
Vol 107 (1) ◽  
pp. 54-59 ◽  
Author(s):  
Carmel Mothersill ◽  
C. Seymour ◽  
J. F. Malone
Keyword(s):  
Electron Microscopy ◽  
Sudden Death ◽  
Primary Culture ◽  
Light And Electron Microscopy ◽  
Functional Differentiation ◽  
Entire Period ◽  
Iodine Uptake ◽  
Long Term Effects ◽  
Thyroid Cells

Abstract. A method is described which permits culture of primary thyroid cells without subculture for at least 100 days. Cultures are maintained without medium changes for the entire period, and concentrated glucose is added to replenish energy supplies at carefully defined intervals. The cells retain morphological and functional differentiation shown by light and electron microscopy, PAS positive histochemistry, iodine uptake and T4 production for at least 100 days. After this time fairly sudden death of the cultures occurs. Possible mechanisms for the effect are postulated. The technique should make it possible to study long-term effects of drugs/radiation on differentiated cultures without the need for continuous subculture.

Long-Term Administration of Ciprofloxacin as the Cause of Ultrastructural Changes in the Liver and Disturbance of Its Functional Balance

2008 ◽  
Vol 14 (S2) ◽  
pp. 1616-1617
Author(s):  
W Matysiak ◽  
B Jodłowska-Jedrych ◽  
E Kifer-Wysocka ◽  
J Romanowska-Sarlej ◽  
K Czerny
Keyword(s):  
New Mexico ◽  
Ultrastructural Changes ◽  
Functional Balance ◽  
Term Administration

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008

scholarly journals Light and electron microscopy characteristics of the muscle of patients with SURF1 gene mutations associated with Leigh disease

2007 ◽  
Vol 61 (4) ◽  
pp. 460-466 ◽  
Author(s):  
M Pronicki ◽  
E Matyja ◽  
D Piekutowska-Abramczuk ◽  
T Szymańska-Dębińska ◽  
A Karkucińska-Więckowska ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Lipid Accumulation ◽  
Morphological Changes ◽  
Light And Electron Microscopy ◽  
Gene Mutations ◽  
Leigh Syndrome ◽  
Typical Feature ◽  
Ultrastructural Changes ◽  
Consistent Feature ◽  
Muscle Changes

Aims:Leigh syndrome (LS) is characterised by almost identical brain changes despite considerable causal heterogeneity. SURF1 gene mutations are among the most frequent causes of LS. Although deficiency of cytochrome c oxidase (COX) is a typical feature of the muscle in SURF1-deficient LS, other abnormalities have been rarely described. The aim of the present work is to assess the skeletal muscle morphology coexisting with SURF1 mutations from our own research and in the literature.Methods:Muscle samples from 21 patients who fulfilled the criteria of LS and SURF1 mutations (14 homozygotes and 7 heterozygotes of c.841delCT) were examined by light and electron microscopy.Results:Diffuse decreased activity or total deficit of COX was revealed histochemically in all examined muscles. No ragged red fibres (RRFs) were seen. Lipid accumulation and fibre size variability were found in 14 and 9 specimens, respectively. Ultrastructural assessment showed several mitochondrial abnormalities, lipid deposits, myofibrillar disorganisation and other minor changes. In five cases no ultrastructural changes were found. Apart from slight correlation between lipid accumulation shown by histochemical and ultrastructural techniques, no other correlations were revealed between parameters investigated, especially between severity of morphological changes and the patient’s age at the biopsy.Conclusion:Histological and histochemical features of muscle of genetically homogenous SURF1-deficient LS were reproducible in detection of COX deficit. Minor muscle changes were not commonly present. Also, ultrastructural abnormalities were not a consistent feature. It should be emphasised that SURF1-deficient muscle assessed in the light and electron microscopy panel may be interpreted as normal if COX staining is not employed.

Mechanisms Controlling Dormancy in the Arid Zone Grass Aristida contorta. II. Anatomy of the Hull

1974 ◽  
Vol 22 (4) ◽  
pp. 647 ◽  
Author(s):  
JJ Mott ◽  
PW Tynan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Gas Permeability ◽  
Arid Zone ◽  
Light And Electron Microscopy ◽  
Anatomical Change ◽  
Definitive Statement ◽  
Scanning Electron

The anatomy of the hull directly over the embryo was examined by light and electron microscopy in long-term dormant and non-dormant grains of A. contorta. A lipid-containing layer was noted, covering the surface of the inner epidermis of the hull, and examination by scanning electron microscopy showed that although the layer was intact in all dormant grain examined, it was fractured in non-dormant grain. A definitive statement on the function of these cracks is not possible, but they appear to be an anatomical change leading to increased gas permeability of the hull of non-dormant grains.

Effects of prolactin on the morphology and function of rat Leydig cells: short-term versus long-term administration

1990 ◽  
Vol 262 (1) ◽  
pp. 41-46 ◽  
Author(s):  
Giuseppina Mazzocchi ◽  
Letizia Cavallini ◽  
Aldona Kasprzak ◽  
Piera Rebuffat ◽  
Gastone G. Nussdorfer
Keyword(s):  
Leydig Cells ◽  
Short Term ◽  
Term Administration ◽  
And Function
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