Biomedical subjects
Publications and source records attributed to J M Lloyd.
A case of myasthenia gravis is described. The diagnosis was confirmed electromyographically and immunologically; the presenting features were those of myofascial pain. Attention is drawn to the association of myofascial pain with other systemic diseases and stresses the need to look critically at the patient for evidence of a systemic origin for myofascial pain.
The API ZYM system, a commercially-available technique that measures bacterial enzyme activity was used to test 43 isolates identified as H. somnus, H. ovis or A. seminis and 19 from related genera. The enzyme patterns resulting from the API ZYM differentiated H. somnus and H. ovis from A. seminis and related genera but not from each other. An identification scheme based on 9 of the enzymes in the API ZYM and a few simple biochemical tests is proposed for the rapid and reliable identification of these bacteria in a diagnostic bacteriology laboratory.
The number of gonadotropin-releasing hormone (GnRH) receptors is known to vary throughout the estrous cycle and in other endocrine states in the rat. These changes in receptors parallel closely the concentrations of serum estradiol during the cycle. In the present study, we used two different cytochemical techniques to determine if changes in GnRH receptors represented alterations in the number of GnRH-receptive cells. Furthermore, we tested the effects of estradiol pretreatment on this phenomenon. Dispersed pituitary monolayers taken at different stages of the cycle were stimulated for 3 min with 1 nM biotinylated [D-lys6]-GnRH (bio-GnRH) which was localized using the avidin-biotin-peroxidase complex (ABC) technique and a black peroxidase substrate. Parallel groups were stained, while living, with an avidin-fluorescein conjugate. Some monolayers were pretreated with physiological concentrations of estradiol benzoate (1 nM-1 pM) prior to bio-GnRH exposure and ABC stains. The resulting stains demonstrated that the percentage of bio-GnRH-receptive cells was 2-3 times greater at 10.00 h proestrus (20.2 +/- 4%) when compared to the same time in estrus (8.7 +/- 2%), diestrus I (5.2 +/- 0.5%), diestrus II (7.6 +/- 1%), and at 17.00 h diestrus II (11.4 +/- 0.9%) and proestrus (7.4 +/- 0.8%). These data correlated well with those obtained from living gonadotropes stained with avidin-fluorescein. Estradiol exerted a biphasic effect dependent upon the stage of the cycle at which the cells were taken.(ABSTRACT TRUNCATED AT 250 WORDS)
Two subtypes of pituitary gonadotropes are known to exist: monohormonal and multihormonal. When separated by centrifugal elutriation monohormonal cells are found in the small fractions whereas multihormonal cells predominate in the large gonadotrope-enriched fractions. Since GnRH is known to shift the proportion of subtypes to cells that are mainly multihormonal, we tested its effect on the small monohormonal gonadotropes. Dispersed cells from cycling female rats were plated on glass coverslips overnight. Storage was evaluated by application of dual immunocytochemical stains with anti-LH beta and anti-FSH beta to cells stimulated with 0.5 nM [D-Lys6]GnRH. Secretion was detected by the reverse hemolytic plaque assay for LH and a newly developed RHPA for FSH. After 4 h of GnRH stimulation, the percentage of total gonadotropes was increased only in fraction (Fr.) 3 [13.9 +/- 0.4% (+/- SE) to 25.2 +/- 2%]. However, cells in Fr. 2 responded with an increase in multihormonal cells from 18.2 +/- 7% to 46.2 +/- 5%, a proportion not different from that in gonadotrope-enriched fractions. GnRH had less striking effects on changing the size or number of LH and FSH plaques. It seems, therefore, that these small gonadotropes are multipotential and respond initially to stimulation by synthesizing and storing the other gonadotropin. In contrast, the large gonadotropes (Frs. 6 and 7) showed no significant changes in storage patterns. Gonadotropes in both fractions were predominantly multihormonal. The LH and FSH reverse hemolytic plaque assays run with cells from Fr. 7 showed striking increases in both the number of plaque-forming cells and the area of the plaques in response to GnRH. However, in the multihormonal cells in Fr. 6, which were 53.5 +/- 9% of the total cell population, a heterogeneous secretory pattern was observed. In the basal state, there were 36.6 +/- 9% LH and only 2.7 +/- 2% FSH plaques, whereas after GnRH stimulation there were 43.1 +/- 10% LH and 10.5 +/- 4% FSH plaques. This finding is the first direct evidence for nonparallel release of gonadotropins from cells known to store both hormones. These studies show that gonadotrope subpopulations exhibit differences in their storage and secretory responses to GnRH. It is suggested that other factors may be required for the release of FSH from unresponsive gonadotropes in Fr. 6.
Anterior pituitary corticotropes represent only 9-10% of the mixed pituitary cell population. However, their small size precludes their enrichment because they cannot be separated from the more abundant PRL and GH cells. They can be induced to enlarge by adrenalectomy, and this report describes the separation of larger CRH-responsive corticotropes from a subpopulation of small pituitary cells. The separation was done by counterflow centrifugation in an elutriator containing the Sanderson chamber which was designed to separate small cells under 15 micron in diameter. The corticotropes were initially eluted at flow rates under 30 ml/min along with other cells less than 12.5 micron in diameter. They were then stimulated for 2-4 h with 0.5 nM CRH and reeluted with the use of higher flow rates to separate the enlarged corticotropes from the unstimulated cells. Reelutriation of the entire pool of small cells produced an enrichment to 60% corticotropes in five separate experiments. However, when the pool was divided into smaller cells (eluted at 20 ml/min) and medium-sized cells (eluted at 30 ml/min), and the two pools were reeluted separately, the enrichment increased to over 90% corticotropes in eight separate experiments. These corticotrope populations remained enriched for up to 14 days in culture. They also secreted in a reverse hemolytic plaque assay that recognizes ACTH-(25-39). The dual labels for ACTH and beta-endorphin showed that 60% of the corticotropes stored both peptides, whereas 30% stored only ACTH, and 10% stored only beta-endorphin. No differences in storage patterns were seen when small and medium-sized corticotropes were compared. Thus, these studies present the first report of the production of an enriched fraction of CRH-responsive corticotropes by counterflow centrifugation and the first report of heterogeneous storage of ACTH and beta-endorphin. The use of enriched fractions facilitated the analysis of these heterogeneous storage patterns in over 8000 corticotropes.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Gonadotropes from cycling female rats were studied to investigate possible mechanisms for the nonparallel release of LH and FSH. The percentages of total gonadotropes increased from 14% during estrus (E) to 18% by diestrous day 2. More of these cells became multihormonal on the morning of proestrus (P; from 46% during diestrus to 69%). Since LH-containing cells increased from 7% at E to 13.3% during early proestrus, this suggests that monohormonal FSH cells may have contributed by synthesizing LH. Gonadotrope cell areas were greatest just before the LH surge (P 1600 h). Microdensitometric measurements demonstrated that the amount and density of immunoperoxidase stain for either gonadotropin subunit were highest during the midafternoon of P. Interestingly, the amount of stain for LH continued to increase during the LH surge, suggesting that the stain had detected newly synthesized LH beta. At the same time, the average density of the LH beta stain decreased. In contrast, the amount, concentration, and density of stain for FSH beta increased during the afternoon of P and decreased during late P and early E. The percentages of granules that contained immunogold stains for only LH or FSH (monohormonal granules) at P 1600-P 1700 h were 3-4 times higher than those in diestrous rats. The percentages of monohormonal LH granules declined during the proestrous surge, whereas percentages of monohormonal FSH granules declined during the first rise (P 1900 h) and after the second rise in serum FSH (E 0800 h). Finally, the average number of gold particles per micron 2 granule area rose over the value in diestrous rats during P 1600-P 1700 h. These studies suggest that multihormonal gonadotropes support nonparallel gonadotropin release by changing the rate of subunit packaging and transit in the Golgi complex.
Patterns of gonadotropin storage in individual gonadotropes change with alterations in the physiological state. After castration in the male rat, there is a 2.5-fold increase in the percentage of gonadotropes and an increase in the proportion of gonadotropes storing both LH and FSH. In addition, there are 6- to 8-fold increases in the pituitary concentrations of LH beta subunit mRNAs. In order to determine whether these changes are due to increases in the number of gonadotropes containing subunit mRNA, or the amount of mRNA per cell or both, an in situ hybridization technique using a photobiotinylated rat LH beta cRNA probe (bio-LH beta-cRNA) was applied to detect LH beta mRNA in fixed whole rat pituitary cells from intact or castrated rats. After hybridization, the bio-LH beta-cRNA was localized with either avidin-biotin peroxidase complex or the fluorescent streptavidin phycoprobe methods. The cells containing LH beta mRNA were then counted and the amount of mRNA per cell was measured by video microdensitometry. Ten percent of the anterior pituitary cells from intact animals contained LH beta mRNA. After castration (2-4 weeks) this percentage rose to 19-24.5%. Image and microdensitometric analyses showed that castration produced a 1.9-fold increase in the amount of LH beta mRNA per cell, and a 2.2-fold increase in the area of cells containing LH beta mRNA. Hence, castration resulted in an increase in the level of LH beta mRNA per cell as well as the number of LH beta mRNA-containing cells. When in situ hybridization was followed by immunocytochemistry in cells from intact rats, 83% of gonadotropes that stained for LH beta and 80% of gonadotropes that stained for FSH beta contained LH beta mRNA whereas after castration 99% of LH-storing and 93% of FSH-storing cells contained LH beta mRNA. This new in situ hybridization protocol is rapid and allows quantification of mRNA within individual gonadotropes. In addition, since the hybridization protocol does not apparently alter the gonadotropin antigens, the hormone content of the same gonadotrope may be defined by immunocytochemistry.
The large volumes of laser plume and char created during carbon dioxide laser endoscopy of the pelvis present a common problem to the gynecologic surgeon. Laser plume not only interferes with the view of the surgical field but also reduces the efficiency of emitted laser energy. A valving system has been designed and clinically tested that allows easy removal of laser-created debris while simultaneously maintaining control of the pneumoperitoneum. The system also removes these gas and liquid products without contaminating the operating room environment or hospital vacuum handling systems.
Explore the source record for details and available documents.
An outbreak of severe atrophic rhinitis is described. A toxigenic strain of P. multocida was isolated from one affected pig. Severe turbinate atrophy was not associated with significantly reduced bodyweight gain in a batch of 34 pigs examined at slaughter. The history of the outbreak suggested that pigs recently introduced from overseas may have been the source of the disease.
Immunohistochemical staining was performed on biopsies and cytological samples from normal, dysplastic and neoplastic squamous epithelia using the monoclonal Ca 1 antibody. The results of staining 92 biopsies and 20 cytological samples are described and it is reported that positive staining with Ca 1 antibody was detected in normal, dysplastic and neoplastic epithelia. The role of the Ca 1 antibody in the study of cervical cancer is discussed.
The distribution of an epitope of the transferrin receptor in the human uterine cervical epithelium has been investigated. Immunohistochemical staining, both immunofluorescent and immunoperoxidase, was performed on biopsy specimens and cytological samples from normal, dysplastic, and neoplastic cervical epithelia using the monoclonal OKT9 antibody. The results of staining 145 cervical biopsy specimens with OKT9 showed widespread staining in all malignant epithelia and most severely dysplastic epithelia. No such staining was seen in either normal epithelia or in mildly dysplastic epithelia apart from the staining of the basal cell layer in some normal epithelia. The incidence of staining in the 50 cervical cytocentrifuge preparations was not as high as that in the 145 tissue sections. The potential role of the OKT9 antibody in both the screening of cervical cytocentrifuge preparations and the prediction of malignancy is discussed. The antibody is considered to be of more value in the examination of biopsy material than of cytocentrifuge preparations.
Immunization of rats with native bovine type II collagen results in a polyarthritis by day 21 in approximately 40% of the rats. Sera of these rats contained anticollagen IgG, principally IgG2a. Small amounts of IgG2b were also detected, but IgG1 and IgG2c were absent. By enzyme-linked immunosorbent assay, the paw tissue of these polyarthritic rats was shown to contain anticollagen IgG, the principal subclass being IgG2a, with minor amounts of IgG2b. Immunofluorescence examination of the paws from polyarthritic rats demonstrated deposition of both IgG and C3 on the articular surface. Passive transfer of disease was accomplished by injection of affinity-purified anticollagen immunoglobulin into naive recipients; paw swelling and histopathologic changes were detected 24 hours after transfer, and by immunofluorescence techniques IgG and C3 deposits were demonstrable on the articular cartilage. On passive transfer, neutrophils invaded the joint space and became juxtaposed to the surface of the articular cartilage. Passive transfer of the disease with anticollagen immunoglobulin was unsuccessful after rats were decomplemented with cobra venom factor; immunofluorescence demonstrated IgG but not C3 on the articular cartilage of these decomplemented rats. In rats decomplemented with cobra venom factor, neutrophils did not accumulate in the joint and erosion of articular cartilage was not detected.
Explore the source record for details and available documents.
This report summarizes the results of the in vitro evaluation of Soviet and American artificial hearts. The devices were tested at the All-Union Institute of Transplantation and Artificial Organs, Moscow, U.S.S.R., and Baylor College of Medicine, Houston, Texas, U.S.A. These studies were designed to standardize procedures to allow comparison of artificial ventricles of different designs. Also, these studies might provide a means for evaluation of other characteristics such as hemolysis, durability, and reliability. Static and dynamic tests were performed, varying preload, afterload, rate, and systolic and diastolic time intervals. All designs demonstrated comparable function curves with capability of taking over the pressure and volume work of the natural heart.