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A histochemical study of oogenesis in the sea urchin, Strogylocentrotus purpuratus
Oögenesis in the sea urchin Strongylocentrotus purpuratus
was studied by histological methods and by histochemical techniques
for polysaccharides, lipids, and nucleic acids Urchins were
collected at Yaquina Head, Oregon at regular intervals between
April 1966 and March 1967. An attempt was made to correlate
seasonal variations in the coastal water temperature with the gonadal
cycle.
The ovaries of the sea urchin are large rebranched sacs covered
with a flagellated peritoneal epithelium. Inside the peritoneum
is a wall of collagenous connective tissue and smooth muscle. In
the central portion of each saccule or acinus of the ovary are two
main cell types: the sex cells, which develop into mature ova, and
the accessory cells or nutritive phagocytes which apparently provide
nutriment for the sex cells.
Oögonia can be found through out the year in small groups scattered along the walls of the ovary, but are most numerous in
the late spring and early summer when the ovary is spent. The
oöcytes start growing in the late summer and early fall when the accessory
cells, which were depleted of nutriments in the spent ovary,
start filling with lipid and polysaccharide globules. At this time the
accessory cells are also found to have inclusions that appear to be
degenerate sex cells. In the late fall and early winter, the oöcytes
continue to grow and their cytoplasm fills with lipid and polysaccharides.
As the ova mature they move from the walls to the central portion of
the acinus where they displace the accessory cells that had formerly
been there.
The ova that have been shed or are about to be shed contain
pyranophilic RNA which is not found in the oöcytes. However, both
ova and oöcytes have RNA that is stainable with azure B. The pyranophilic
RNA is also found in accessory cells.
Since all the oöcytes do not mature at the same time, a sea
urchin is able to shed many times during the breeding season which
lasts from late winter to early spring, During this period the accessory
cells progressively lose their globules. When the accessory
cells are finally depleted of their lipid and polysaccharide, the
öócytes no longer grow and the ovaries are spent
A HISTOCHEMICAL STUDY OF OOGENESIS IN THE SEA URCHIN, STRONGYLOCENTROTUS PURPURATUS
Volume: 136Start Page: 167End Page: 18
Isolation of Kurthia gibsonii from non-gonorrheal urethritis: Implications for the pathomechanism upon surveying the literature
The incidence and number of species involved in the spectrum of sexually transmitted infections continue to increase. Laboratories have to be prepared for identification of unusual microbes. In our practice, a male patient had recurring urethritis and balanitis after having repeated unprotected insertive sexual intercourse with female piglets. He also had allergy to scents and some metals, otherwise he showed no general symptoms. Specimens were swabbed from the urethra, inflamed glans, rectum, mouth onto several culture media, subsequently isolates were tested for their morphology, biochemical activity. Kurthia gibsonii was isolated from urethra and glans. No concomitant infection with other microbes was detected, haemoculture was negative. Relying upon antibiotic sensitivity test, he was cured with 2 × 500 mg oral cefuroxime for 15 days, and topical gentamycin cream for 2 months. This is the first reported sexually transmitted, zoonotic infection without generalization by Kurthia spp. We report first the antibiogram of K. gibsonii. Slight differences in the antibiotic sensitivity suggest independent infection and sensitivity of urethral and mucous membrane tissues to distinct K. gibsonii strains. Allergy of the patient might predispose to opportunistic infection. Such aspects ought to be tested in details in further cases
Spectrum of Kaposi's Sarcoma-Associated Herpesvirus, or Human Herpesvirus 8, Diseases
Human herpesvirus 8 (HHV-8), also known as Kaposi's sarcoma-associated herpesvirus (KSHV), discovered in 1994, is a human rhadinovirus (gamma-2 herpesvirus). Unlike other human herpesviruses (herpes simplex virus, Epstein-Barr virus, varicella-zoster virus, cytomegalovirus, HHV-6, and HHV-7), it is not widespread in the general population and has many unique proteins. HHV-8 is strongly associated with all subtypes of Kaposi's sarcoma (KS), multicentric Castleman's disease, and a rare form of B-cell lymphoma, primary effusion lymphoma. In addition, HHV-8 DNA sequences have been found in association with other diseases, but the role of the virus in these diseases is largely unconfirmed and remains controversial. The seroprevalence of HHV-8, based on detection of latent and lytic proteins, is 2 to 5% in healthy donors except in certain geographic areas where the virus is endemic, 80 to 95% in classic KS patients, and 40 to 50% in HIV-1 patients without KS. This virus can be transmitted both sexually and through body fluids (e.g., saliva and blood). HHV-8 is a transforming virus, as evidenced by its presence in human malignancies, by the in vitro transforming properties of several of its viral genes, and by its ability to transform some primary cells in culture. It is not, however, sufficient for transformation, and other cofactors such as immunosuppressive cytokines are involved in the development of HHV-8-associated malignancies. In this article, we review the biology, molecular virology, epidemiology, transmission, detection methods, pathogenesis, and antiviral therapy of this newly discovered human herpesvirus