A brief history of testosterone.

PURPOSE: We explore the history of testosterone in the context of medical and scientific developments. MATERIALS AND METHODS: A review of the scientific and historical literature was conducted. RESULTS: The origins and effects of testosterone have been recognized throughout the history of humankind. Hunter performed testicular transplantation experiments in 1767 while studying tissue transplantation techniques, and almost a century later Berthold linked the physiological and behavioral changes of castration to a substance secreted by the testes. Brown-Séquard gave birth to the field of organotherapy in 1889 when he announced that his auto-injection of testicular extracts resulted in rejuvenated physical and mental abilities. Steinach and Niehans expanded upon Brown-Séquard's work with rejuvenation treatments involving vasoligation, tissue grafts and cellular injections. In 1935 David et al isolated the critical ingredient in organotherapeutic treatments, testosterone. CONCLUSIONS: The effects of the powerful hormone testosterone continue to inspire research and controversy 65 years later.

A comparison of the toxinological characteristics of two Cassiopea and Aurelia species.

A comparison of the toxinological properties of nematocyst venoms from Old and New World Cassiopea and Aurelia species was undertaken. The cnidom of venomous Cassiopea andromeda (Ca) and Aurelia (Aa(RS)) from the Red Sea was identical to that of nonvenomous Bahamian Cassiopea xamancha (Cx) and Chesapeake Bay Aurelia aurita (Aa(CB)), respectively. A clean nematocyst preparation of Ca and both Aurelias could be obtained but algal particles could not be separated completely from the Cx nematocysts. Further purification of all four nematocyst preparations showed significant differences in the action of their protein. Only the Cassiopea had coexisting dermonecrotic and vasopermeability producing properties and Ca's hemolytic activity was associated with mouse lethality. The protein, hemolysin and phospholipase gel filtration eluant curves of Ca venom were similar. Venomous Aa(RS) actively stung lips and contained more potent mouse lethal, demonecrotic, vasopermeability plus hemolytic factors than Aa(CB). Cross reactivity of convalescent human serum obtained from patients stung by Ca and venomous Cx collected in Central America occurred. This was also observed between sera of bathers stung by Aa(RS) and stinging Aurelia which appeared in Florida during the recent El Niño year. IgG was stimulated by several nematocyst proteins since many venom subfractions tested positive at high titers against convalescent sera. T-cell proliferation of mice primed with either Aurelia venom was positive against the homologous preparation with cross reactivity to the heterologous venom. Crude venoms of both Red Sea jellyfish metabolically stimulated cultured human hepatocytes more than their New World counterparts. This data shows that considerable similarities and differences exist in the venoms of these Old and New World Cassiopea and Aurelia medusae with the Eastern species being more potent.

Allergic colitis: a mimic of Hirschsprung disease.

BACKGROUND: Allergy to cow milk protein is a common cause of gastrointestinal symptoms in infancy. Milk allergy is usually a clinical diagnosis, and thus there have been few reports of the radiographic findings. OBJECTIVE: To describe the barium enema findings of allergic colitis and differentiate them from Hirschsprung disease. Materials and methods. Four infants (age range 7 days-5 weeks) with constipation underwent barium enema to exclude Hirschsprung disease. Radiographic findings were correlated with the pathologic specimens from suction rectal biopsy. RESULTS: All enemas revealed irregular narrowing of the rectum and a transition zone. Rectal biopsies in each case demonstrated ganglion cells and evidence of an allergic colitis, with inflammatory infiltrates in the lamina propria. A diagnosis of milk allergy colitis was made and symptoms resolved after removal of milk from the diet. CONCLUSIONS: Milk allergy is common in infancy. The rectum is a primary target organ, with allergic colitis often diagnosed on clinical grounds alone. However, a child with allergic colitis may be referred to radiology for barium enema, especially if constipation is present. The radiologist should be aware of the unique imaging findings of allergic colitis, so as to avoid confusion with Hirschsprung disease and perhaps an unnecessary rectal biopsy.

Partial purification of box jellyfish (Chironex fleckeri) nematocyst venom isolated at the beachside.

Chironex fleckeri, the northern Australian box jellyfish produces one of, if not, the most potent animal venoms. Study of the venom has been hampered by the limits of the animals' range and the venom's thermolability. Using retained lethality and native polyacrylamide gel electrophoresis (NPAGE), we show that lyophilization of autolysis isolated nematocysts is an effective method of transporting the venom. In addition, Sephadex G-200 chromatography, spin concentration, and NPAGE fail to demonstrate the presence of a 600 kDa protein to which the bulk of the lethal activity has been ascribed. Sodium dodecyl sulfate capillary electrophoresis of crude venom yields several protein bands with a molecular weight range of 30-200 kDa. Freeze-thaw studies show a loss of activity and NPAGE bands after two freeze thaw cycles.

Autonomic neurotoxicity of jellyfish and marine animal venoms.

Venoms and poisons of jellyfish and other marine animals can induce damage to the human nervous and circulatory systems. Clues to the pathogenesis and clinical manifestations of these lesions can be obtained from data of human envenomations and animal experimentation. Because many investigators are unaware that marine animal venoms have autonomic actions, this paper aims to elucidate the broad antagonistic or toxic effects these compounds have on the autonomic nervous system. Marine venoms can affect ion transport of particularly sodium and calcium, induce channels or pores in neural and muscular cellular membranes, alter intracellular membranes of organelles and release mediators of inflammation. The box jellyfish, particularly Chironex fleckeri, in the Indo-Pacific region, is the world's most venomous marine animal and is responsible for autonomic disorders in patients. The symptoms induced by these venoms are vasospasm, cardiac irregularities, peripheral neuropathy, aphonia, ophthalmic abnormalities and parasympathetic dysautonomia. Cases of Irukandji syndrome, caused by the jellyfish Carukia barnesi, have symptoms that mimic excessive catecholamine release. Coelenterate venoms can also target the myocardium, Purkinje fiber, A-V node or aortic ring. Actions on nerves, as well as skeletal, smooth or cardiac muscle occur. Recent studies indicate that the hepatic P-450 enzyme family may be injured by these compounds. The multiplicity of these venom activities means that a thorough understanding of the sting pathogenesis will be essential in devising effective therapies.