Cessation of spermatogenesis in juvenile spermatogonial depletion (jsd/jsd) mice

Several lines of evidence have suggested that decreases in postsynaptic inhibition may have a role in epileptogenesis in cortical structures. However, other studies have suggested that GABAergic inhibition is spared, or even augmented in some forms of post-lesional epilepsy. In the studies described here, inhibitory events were recorded in two models of post-lesional chronic epileptogenesis. (i) As previously reported (D.A. Prince and G.-F. Tseng. J. Neurophysiol. 69: 1276-1291. 1993), epileptiform activity develops in slices from partially isolated rat neocortical islands 2-3 weeks after the initial in vivo lesion. In this model of post-traumatic epilepsy, large amplitude polyphasic inhibitory postsynaptic currents (IPSCs) in layer V pyramidal neurons are associated with each interictal epileptiform field potential. The frequency of spontaneous IPSCs as well as miniature IPSCs was significantly increased in neocortical slices from the epileptogenic chronically injured cortex versus controls. Immunocytochemical reactions for parvalbumin and calbindin, calcium binding proteins present in subgroups of GABAergic neurons, showed an increased staining of both neuropil and somata within the epileptogenic tissue. Immunoreactivity for glutamic acid decarboxylase (GAD) and GABA also appeared to be increased in the neuropil. (ii) Cortical microgyri resembling human malformations were produced by freeze lesions made transcranially in P0 rat cortex (K.M. Jacobs, M.J. Gutnick, and D.A. Prince. Cereb. Cortex, 6: 514-523. 1996). The boundary between the four-layered microgyrus and surrounding cortex become epileptogenic within about 2 weeks, as judged by evoked extracellular field potentials and cellular activities. Epileptogenesis in the surrounding cortex is not altered when the microgyrus itself is isolated by transcortical cuts. Patch-clamp recordings from layer V neurons in the epileptogenic zone showed that spontaneous IPSCs are larger and more dependent on glutamatergic synapses than in control neurons. The amplitudes of polysynaptic IPSCs evoked by threshold stimulation were also larger than in control cells. Although evaluation of inhibitory events in these models is still incomplete, results to date suggest that GABAergic inhibition may be enhanced in epileptogenic areas associated with chronic cortical injury. Sprouting of axonal arborizations of pyramidal cells onto interneurons, upregulation of GABAergic neurons, and perhaps sprouting of inhibitory axons that make increased numbers of contacts onto pyramidal cells may all contribute to the increased inhibitory drive. Results in these models do not support the disinhibitory hypothesis of chronic epileptogenesis.     

Papillary eccrine adenoma: immunohistochemical studies of keratin expression

Despite various studies, there are serious disagreements about the cellular differentiation of papillary eccrine adenoma. In the present study, 2 specimens of papillary eccrine adenoma were analyzed by immunohistochemical techniques, using a panel of monoclonal antibodies against keratins, to elucidate its differentiation. Histopathologically, the tumor was composed of multiple tubular structures lined by two or more layers of epithelial cells. The luminal cells of the tubules were flattened or cuboidal. The former were noted in large dilated tubules. The latter were usually observed in small-to-moderate-sized tubules, and formed intraluminal papillary projections in some tubules. Immunohistochemically, there were two kinds of cuboidal cells in the luminal layers of the tubules. Most of the large dilated tubules and some of the small-to-moderate-sized tubules expressed immunophenotypes similar to those of the eccrine dermal duct. The other tubular structures, including the small tubules resembling those of syringoma, expressed immunophenotypes similar to those of the transitional portions between the dermal ducts and the secretory segments of eccrine glands. From the above comparative studies, papillary eccrine adenoma is considered to differentiate towards the dermal duct and the transitional portions between the dermal ducts and the secretory segments of eccrine glands.     

A 400 K-transistor CMOS sea-of-gates array with continuous track allocation

A 0.8- mu m CMOS sea-of-gates (SOG) array with first-level wiring channels perpendicular to transistor rows and 40 0K transistors is integrated on a 6*7-mm/sup 2/ chip. Implementation of a 64-bit multiplier shows 60-percent gate utilization and density of 1410 G/mm/sup 2/. The wiring length of the multiplier is 70 percent of that in a conventional SOG.<>     

Anastomosis of the left juxtaposed atrial appendages in a patient with tricuspid atresia

A 9-month-old boy with left juxtaposition of the atrial appendages, tricuspid atresia, pulmonary atresia, and ventriculoarterial discordance underwent anastomosis between the atrial appendages after failure of balloon/blade atrial septostomy because of restrictive atrial septal defect. For surgical creation of atrial communication in patients with juxtaposed atrial appendages, anastomosis between the atrial appendages seemed to be safer, more effective, and less invasive than septectomy by Blalock-Hanlon technique or inflow occlusion technique.     

Simultaneous operation of intra-descending aorta bypass grafting and brachiocephalic artery reconstruction in a patient of aortitis syndrome

OBJECTIVE: To determine the intracavernous partial oxygen pressure in different etiological groups of erectile dysfunction: psychogenic (control group), arterial and veno-occlusive and the value of intracavernous gasometry as an indicator of the degree of severity of impotence. METHODS: A total of 16 patients were evaluated according to the diagnostic protocol utilized to determine the etiology of erectile dysfunction. Intracavernous blood samples were obtained during the initial phase of gasometry and PO2 was determined by standard gasometric methods. RESULTS: After injection of the vasoactive drug, the mean intracavernous PO2 was 92.4 +/- 1.27 for the control group, 62.2 +/- 0.85 for the group with arterial impotence, and 76.8 +/- 1.45 for the group with venous impotence, demonstrating a statistically significant difference (p < 0.01). CONCLUSIONS: Intracavernous gasometry, in combination with other diagnostic tests, is useful for evaluating the degree of severity of erectile dysfunction. The reduction in cavernous oxygen tension, which induces cavernous tissue fibrosis, can be considered to be a common mechanism in arterial and venous impotence.     

Effect of ferrous ion on mildiomycin production by Streptoverticillium rimofaciens

A specific regulatory effect of ferrous ion on a biosynthesis of mildiomycin by Streptoverticillium rimofaciens was investigated. The minimal concentration of ferrous ion necessary for the maximal production of mildiomycin was about 8 micrograms/ml. The physiological effects of ferrous ion on the mildiomycin production were examined in the media with and without the ferrous ion. Addition of ferrous ion to the culture medium increased both the mildiomycin production (10 times) and an assimilation of ammonium-nitrogen, activities of peptidase and protease.     

Vasoinhibitory effect of leminoprazole, a H+,K(+)-ATPase inhibitor, on rat aortic rings

The effects of the marine ascidian compound bistratene A on in vitro cultures of Plasmodium falciparum were assessed. Concentrations from 0 to 1.5 micrograms ml(-1) of the compound were tested. The parasitaemia in asynchronous cultures treated with bistratene A increased normally over the first 40 h, then decreased leaving only gametocytes. When synchronized cultures were treated with a constant dose of 50 ng ml(-1), gametocytes developed more rapidly than they did in control cultures. In addition, gametocytes developed in drug-treated cultures of P. falciparum that normally do not produce gametocytes. Bistratene A appears to inhibit merozoite invasion as well as to induce gametocytogenesis.