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Biomedical subjects

H D Geissinger

Publications and source records attributed to H D Geissinger.

At least 19 recordsLinked to original sources
PubMed1991

Morphometric and steroid hormone changes associated with experimental anovulatory follicles in the sow.

Steroid levels and ovarian follicular morphology were examined in sows on days 19 and 26 (day 5 of next cycle) after injection of adrenocorticotropic hormone (ACTH) or dexamethasone (DXM). Five sows received DXM (30 micrograms/kg bodyweight, intramuscularly) at 12 h intervals from days 9 to 14. Another five sows were given ACTH (2 IU/kg bodyweight, intramuscularly) from day 17 to day 19 or the end of estrus. Five control sows received no treatment. Ovulation occurred only in control sows and progesterone was significantly elevated at day 26. Estradiol values in ovarian vein blood were low but variable on day 19 in DXM- and ACTH-treated animals. Androstenedione values were lower (p less than 0.05) on both days in sows receiving DXM but not in those given ACTH compared to control values on day 19. Morphometric analysis, based on six follicles in each of three sows from each treatment group, indicated that follicular and antral diameters and granulosa cell numbers did not differ for either hormone treatment group on either day compared to those of control sows on day 19. The mitotic index suggested that cell replication continued. However, pyknotic and karyorrhectic nuclei were also seen in the hormone treatment groups. Follicles and oocytes from both DXM- and ACTH-treated sows showed signs of early degenerative changes including disorganization of cumulus cells and large lipid droplets in the cytoplasm of oocytes. Significant differences from control follicles in granulosa cell density and theca interna cell density suggested an association with the altered steroid hormone secretion.

Adrenocorticotropic Hormone↗
PubMed1990

"mdx" mouse myopathy: histopathological, morphometric and histochemical observations on young mice.

Histopathological examination of tibialis anterior (TA) and lateral gastrocnemius (LG) muscles from "mdx" mice sometimes revealed lesions of calcification and the close proximity of degenerative lesions with regenerative changes. Morphometric examinations showed that the TA was more severely affected than the LG in mice of all age groups. The soleus muscle was less severely affected than the TA in very young mice, but appeared to be affected almost as severely as the TA in older mice. Type 1 myofibres were more acid-labile in the mdx mice than in control mice and all three major fibre types degenerated and subsequently regenerated in young mdx mice. The aetiological significance of the above findings is unknown at present.

Animals↗
PubMed1985

Copper-induced myopathy in rabbits: ultrastructural observations.

Mature rabbits were injected intra-muscularly into the hamstring (HS) muscles with doses of 1.66 mg Cu/kg/day, as cupric acetate, in aqueous solution. Similar doses of Na acetate were injected into control rabbits. Skeletal (HS) and cardiac (MYO) muscles were examined by scanning electron microscopy, transmission electron microscopy and a microanalyzer and energy dispersive X-ray (MEDX). Na-injected rabbits showed slight myofibrillar lesions in HS after four injections, and mitochondrial inclusions in MYO were noted after two or seven injections. No Cu was found with MEDX. Cu-injected rabbits showed that the severity of lesions of myofibrillar degeneration and mitochondrial inclusions in HS increased with the number of injections and days the rabbits had been on experiment. After seven days on experiment signs of muscle regeneration were seen. Cu was found first to localize in the nucleus of HS after one day, thereafter it localized in the mitochondria after three and seven days. MYO lesions were found in the mitochondria after six or seven days after Cu-injection. With MEDX less Cu was found than had been found in HS. This Cu first localized in the nucleus of MYO after one day and then disappeared from the tissue altogether.

Animals↗
PubMed1985

Scanning and transmission electron microscopic studies on the oviducts of Pekin ducks fed methyl mercury containing diets.

This study was undertaken to examine the effects of varying levels of methyl mercury (MeHg) on the ultrastructure of the surface epithelium of the oviduct of ducks. Accordingly, Pekin ducks were maintained on feed containing varying doses of (0.0; 0.5; 5.0; 15.0 ppm) of MeHg (Group I - control to IV) for 12 weeks and sacrificed. Tissue from the magnum and the shell gland regions of the oviduct was processed for scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that the primary and secondary folds of these regions of the oviducts of the control and 0.5 ppm treatment group were densely populated with ciliated cells and that the cilia tend to cover the apical surfaces of the non-ciliated secretory cells. This unchanged ultrastructural morphology of the surface epithelium of 0.5 ppm treatment group was verified with TEM. The ciliated and nonciliated cells in surface epithelium appeared to be equal in frequency. The nuclei of ciliated cells were superficial in location compared to nonciliated secretory cells which had nuclei in the basal part of the cytoplasm. In the oviductal tissues from ducks fed 5.0 ppm MeHg isolated areas of ciliary loss, but minimal disruption of the apical plasma membrane were observed by SEM. In a few birds plasma membrane lesions, condensation of nuclear chromatin and very dilated rough endoplasmic reticulum were seen with TEM. In the oviductal tissues from ducks fed 15.0 ppm MeHg it could be seen that ciliary loss was much more extensive than hitherto observed, and disruption of the apex of cells could be seen. TEM showed degeneration of cytoplasmic organelles, more or less severely damaged ciliated cells, loss of ciliary extensions and formation of compound cilia. These observations indicate that methyl mercury at 5.0 and 15.0 ppm dose levels causes toxic injury to oviductal surface epithelium of Pekin duck that may cause reduced reproductive capability.

Animals↗
PubMed1983

A correlative study of porcine endometrium and hormone levels during early lactation and the late luteal phase.

This study sought to determine what morphological similarities there were between sow uterus 6-10 days post-partum and during the late luteal phase of the estrous cycle (day 14 post-estrum). An attempt to assess blastocyst receptivity was made. SEM examination of the uterine surfaces in all sows revealed two distinct types of gland openings: 1) Several wider openings (40-60 microM diam.) were always surrounded by large numbers of ciliated cells. At day 7 post-partum distinct epithelial "ridges" surrounding these ciliated patches were very pronounced and consisted of proliferating/differentiating non-ciliated cells. These "ridges" seemed to appear as "valleys" on day 8 post-partum and were densely populated with cells bearing a single cilium. 2) Smaller, (2-4 micron diam.) more numerous gland openings were not associated with large numbers of ciliated cells. The larger gland openings were more numerous in post-partum uterus. Surface and glandular epithelial heights were similar in all sows. Circulating levels of steroids and prostaglandins were very low in post-parturient sows and appeared to exert little effect on cell morphology. Secretory cells lacking microvilli appeared around days 6 and 7 post-partum but were less prominent around days 8-10 post-partum. Several similarities were noted between the luteal phase uterus and the uterus at days 8 and 9 post-partum. These included cell heights, lipid inclusions and large secondary lysosomes, the amount of breakdown within the surface epithelium, and the densities of the zona compacta and the zona spongiosa. It was concluded that attempts at blastocyst implantation might be feasible at around days 8 and 9 post-partum.

Animals↗
PubMed1982

The pulmonary clearance of Pasteurella haemolytica in calves infected with bovine virus diarrhea or Mycoplasma bovis.

Based on current literature which commonly associates bovine virus diarrhea virus and Mycoplasma bovis with "pneumonic pasteurellosis," an investigation was conducted into the effect of these two pathogens on the capacity of bovine lung to clear inhaled Pasteurella haemolytica. There was no significant effect (p less than 0.05) of either bovine virus diarrhea virus or M. bovis on the mean clearance rate of P. haemolytica, nor did the time interval of three, five or seven days between the first inoculation and exposure to P. haemolytica and adversely affect the lung clearance rates. However, it was found that the left lungs and a higher bacterial retention (p less than 0.05) than the right lungs.

Animals↗
PubMed1981

Preparation of muscle samples for electron microscopy.

The relevant literature on EM preparation techniques for muscle is reviewed. The currently available methodologies are presented and critically discussed from the point of view of the biologist and the food scientist. Those SEM and TEM procedures which have proved to be most useful in the present state of the art of specimen preparation for EM are summarized. Some of the more recently available staining and fracturing procedures for muscle, as well as specimen preparation procedures for intermicroscopic (LM, SEM, TEM) correlation are stressed. It is proposed that the normal ultrastructural appearance of muscle should serve as a baseline for the ultrastructural examination of meat.

Animals↗
PubMed1981

Copper-induced skeletal myopathy in rabbits.

Doses of 1.66 mg Cu/kg/day, as cupric acetate in aqueous solution, were injected intramuscularly into the lateral thigh muscles of rabbits. The rate of loss of Cu from the injection site was estimated from in vivo measurements of 64Cu injected on the 15th day. Biological half-life values were 1.0 h for the first component (accounting for 65.2% of the 64 Cu) and 14.6 h for the second component (34.8% of the 64Cu). For the control group, values were 0.8 h and 62.2%, 14.6 h and 37.8%. Grossly visible lesions of dermatitis were noted on the paws, i.e. at sites removed from the site of injection, in some rabbits injected with Cu acetate two days post injectionem (p.i.). Histologically detectable lesions of acute inflammation were seen as early as 24 hours p.i. at the injection site of rabbits which had been exposed to the Cu once. Multiple injections and longer time periods resulted in lesions of acute and chronic inflammation. Cu was detected by the use of rubeanic acid stain. Signs of muscle degeneration and regeneration were seen as early as three days p.i. in rabbits which had received two injections of Cu. Rabbits which had been killed six days p.i. after a single injection showed chronic inflammatory changes and newly formed myofibres. Rabbits which had been killed 37 days p.i. after 17 injections showed lesions of acute and chronic inflammation of muscle and surrounding connective tissue, as well as signs of muscle regeneration. The gangrene visible grossly was attributed to the ischaemia caused by conglomerations of Cu.

Animals↗
PubMed1980

An improved direct intermicroscopic (LM leads to SEM leads to TEM) correlative procedure for the examination of mammalian skeletal muscle.

The procedure for direct intermicroscopic (LM leads to SEM leads to TEM) correlation of muscle was modified. The major modification was the use of cryostat sections which showed far better ultrastructural preservation than did paraffin sections. The use of an osmium-thiocarbohydrazide ligand binding procedure (OTOTO) did not noticeably improve the scanning electron microscopic (SEM) image, but did result in a subsequent transmission electron microscopic (TEM) image which showed increased contrast of the intracellular membranous components. Besides improving the preservation at the TEM level of examination, the techniques used to locate the same structure or area previously examined under the complementary modes of microscopy (i.e. LM and SEM), were also refined.

Animals↗
PubMed1980

Scanning electron, light optical, and transmission electron microscopy and plasma steroid values of porcine uterus at lactation.

Sows, while nursing litters for a period of 4 to 8 weeks, do not ovulate, thereby delaying the time sows can be rebred. Therefore, this study sought to determine how soon after parturition the morphological appearance of the uterus was such that blastocyst implantation could possibly proceed. Biopsy samples taken immediately post-partum and on days 1, 2, 3, 4 post-partum show that the endometrium was considerably damaged as evidenced by sloughing of the zona compacta and zona spongiosa and the presence of leukocytes around the surface epithelial (SE) cells. Around the 6th day post-partum the numbers of leukocytes were reduced and regeneration of the SE was evident. Around the 8th day post-partum, SE cells appeared similar to those of normal cyclic sows in the late luteal phase (i.e. 15 days post-estrum). Under normal breeding conditions, blastocyst implantation takes place during the late luteal phase. From 17 to 26 days post-partum the SE cells appeared similar to those of normal cyclic sows in the early follicular phase (i.e. 21 days post-estrum), and the subepithelial layers seemed edematous. Estradiol and progesterone concentrations dropped markedly at parturition and remained low up to the 26th day of lactation. Although there was considerable heterogeneity of samples between sows it was concluded, from the morphological results, that plasma steroid levels exert relatively little effect on the sow endometrium up to 26 days post-partum. If ovulation could be induced or ova transplant be performed in lactating sows the endometrium would appear ready for blastocyst implantation after day 8 post-partum.

Animals↗
PubMed1978

Microbodies of the pig liver. A morphologic and morphometric study.

The ultrastructure of hepatic microbodies of pigs was studied in liver samples fixed in phosphate-buffered 2% glutaraldehyde (pH 7.4) and postfixed in 2% osmium tetroxide. The microbodies were rounded or ovoid in shape and contained a granular matrix enclosed with a single limiting membrane. The matrix, in many of the organelles, contained an amorphous or an organized (crystalloid) area. The crystalloids were organized as fine, alternating electron-opaque and electron-lucent lines, or as groups of tubules arranged in more than one plane. Profiles of smooth endoplasmic reticulum were usually found near the microbodies. 34 microbodies were approximately 0.67 +/- 0.02 micrometer (mean +/- standard error) in length and were approximately 0.56 micrometer (+/- 0.02 micrometer) wide. The marginal plates consisted of strata which exhibited a periodicity. The average length and width of 17 plates was approximately 0.34 +/- 0.03 micrometer and 0.002 micrometer, respectively. This study clearly establishes the occurrence of marginal plates in microbodies of porcine liver.

Animals↗
PubMed1978

Experimental polychlorinated biphenyl toxicosis in germfree pigs.

The effects of polychlorinated biphenyls were studied in eight germfree pigs. Beginning at fourteen days of age, two pigs each were fed daily 12.5, 25, 50 and 100 mg/kg body weight of polychlorinated biphenyls as Aroclor 1254. Three germfree pigs were negative controls. Clinically the treated pigs had inappetance, a hemorrhagic diarrhea, erythema of the nose and the anus, retarded growth, distended abdomen and at the higher dose levels, incoordination and coma followed by death. Deaths occurred in 11 to 35 days after exposure. At necropsy, the piglets exhibited grossly enlarged mottled liver, erosions of the gastric mucosa, hemorrhages through the mesentery and the intestinal wall, a fibrinous pericarditis, a hypoplastic thymus and congested swollen thyroid glands. The histopathological lesions included hepatic centrolobular necrosis, interstitial myocarditis, endocarditis, myopathy of the muscles, gastric erosions and colitis. All of the organs examined for polychlorinated biphenyls had elevated residue levels which were particularly high in the fat, liver, psoas muscle, brain and kidney and were higher than has been reported in conventional pigs fed approximately equal concentrations of polychlorinated biphenyls. The severity of clinical signs, pathological changes and tissue concentrations were directly related to the dose administered and were more pronounced in the germfree pigs than has been described in conventional pigs.

Adipose Tissue↗
PubMed1977

Swine dysentery: inoculation of gnotobiotic pigs with Treponema hyodysenteriae and Vibrio coli and a Peptostreptococcus.

Pure cultures of Treponema hyodysenteriae given orally to conventional pigs resulted in the development of swine dysentery, whereas identical cultures given to gnotobiotic pigs did not produce the disease. Oral inoculation of gnotobiotic pigs with Vibrio coli and/or a peptostreptococcus in addition to T. hyodysenteriae did not result in dysentery. Neutralization of gastric secretions with NaHCO3 immediately prior to inoculation with T. hyodysenteriae increased the period during which treponemes were evident in the feces, as did the inoculation of this organism via the intracecal route. None of the gnotobiotic pigs with a persistent fecal Treponema population developed signs of dysentery. Factors other than those investigated in this work must play a part in the etiology of swine dysentery.

Animals↗