Identification of two polyketide synthase gene clusters on the linear plasmid pSLA2-L in Streptomyces rochei.

The 200kb linear plasmid pSLA2-L was suggested to be involved in the production of two macrolide antibiotics, lankamycin (Lm) and lankacidin (Lc), in Streptomyces rochei 7434AN4. Hybridization experiments with the polyketide synthase (PKS) genes for erythromycin and actinorhodin identified two eryAI-homologous regions and an actI-homologous region on pSLA2-L. The nucleotide sequence of a 3.6kb SacI fragment carrying one of the eryAI-homologs revealed that it codes for part of a large protein with four domains for ketoreductase, acyl carrier protein, ketosynthase, and acyltransferase. Gene disruption confirmed that the two eryAI-homologs are parts of a large type-I PKS gene cluster for Lm. A 4.8kb DNA carrying the actI-homologous region contains four open reading frames (ORF1-ORF4) as well as an additional ORF, i.e. ORF5, which might code for a thioesterase. Deletion of the ORF2-ORF4 region showed that it is not involved in the synthesis of Lm or Lc. Thus, it was confirmed that pSLA2-L contains two PKS gene clusters for Lm and an unknown type-II polyketide.

Overall distribution of substance P nerves in the rat cornea and their three-dimensional profiles.

The overall distribution of substance P-like immunoreactive (SPI) fibers, examined by using whole-mounts of the rat cornea, was investigated by means of indirect immunofluorescence. SPI fibers entered the cornea from two levels; one from the middle layer of the sclera and the other from the episclera. From the sclera, a thick SPI fiber trunk, extending to the central part, subdivided into smaller SPI fiber bundles and approached the epithelium. The SPI fiber bundles from the episclera were smaller than those from the sclera. However, both fiber bundles formed a dense fiber network in the uppermost part of the stroma. This fiber plexus dissociated into SPI fibers extending to the superficial part of the epithelium where they formed an abundant arborization of fine SPI fibers. The results suggest that these fibers originate from SPI neurons in the trigeminal ganglion.

Leucine-enkephalin-like immunoreactivity in the chicken retina with a special reference to its fine structures.

Leucine-enkephalin-like immunoreactivity (LEI) in the chicken retina was investigated using light and electron microscopic immunohistochemistry. A flat-mount technique for light microscopy clearly demonstrated that LEI cells were distributed widely throughout the entire retina, without any differences between the central and peripheral retinal regions. Frozen sections for light microscopy confirmed the previous findings in pigeons that LEI is localized in amacrine cells. The present electron microscopic observations confirmed the findings of light microscopy and revealed that LEI terminals make synaptic contract mainly with vesicle-containing processes that seemed to belong to the amacrine cells. The present study further suggests that LEI terminals are both pre- and postsynaptic elements onto vesicle-containing processes mentioned above.

Effects of KRN2391 on ionic currents in rabbit femoral arterial myocytes.

The effects of KRN2391, an ATP-sensitive K+ channel opener (KCO) which also acts as a nitrate, on ionic membrane currents in rabbit femoral arterial myocytes were examined. Under whole-cell clamp conditions where cells were superfused with physiological salts solution containing 5.9 mM K+, KRN2391 elicited an outward current at a holding potential of -30 mV. KRN2391-induced current had a reversal potential of -78 mV and was abolished by glibenclamide (glib). KRN2391 was approximately 25 times more potent than nicorandil to activate an ATP-sensitive K+ current (I:(KATP)). On the other hand, 10 microM KRN2391 did not affect either voltage-dependent Ca(2+) or delayed rectifier K+ channel currents. In the inside-out patch configuration, KRN2391 activated 47 pS K+ channels in the presence of nucleotide diphosphates (NDPs) under the symmetrical 140 mM K+ conditions. Glib and intracellular ATP reversibly inhibited the activity of the 47 pS K+ channels. The 47 pS K+ channels activated by KRN2391 are similar in their conductance and other properties to NDP-sensitive K+ channels (K(NDP) channels) described in other smooth muscles and the cloned channels. KRN2391 is a potent activator of the 47 pS K+ channels and the activation can contribute to the KRN2391-induced vasodilation in arterial muscles.

Ontogeny of substance P-containing structures in the ocular tissue of the rat: an immunohistochemical analysis.

The ontogeny of the substance P-like immunoreactivity (SPI) containing system in the ocular tissue of the rat was examined by means of the indirect immunofluorescence method. SPI-containing amacrine cells first appeared at postnatal day 4 and displaced SPI-containing amacrine cells at postnatal day 5. After this time, they developed markedly reaching their maximum content and distribution at postnatal day 14. On the other hand, SPI-containing cells in the trigeminal ganglion were first seen at gestational day 17 and reached their maximum content at birth. SPI-containing fibers in the cornea and uvea were first observed at gestational days 17-19. The SPI-containing fibers in the iris reached their maximum content at birth, while those in the cornea, choroid and ciliary body were fully developed at postnatal day 3. In the adult rats, numerous SPI structures were still seen in the ocular tissue, retina, cornea and uvea. These findings suggest that SPI might play some role in the developing ocular tissue in addition to its neurotransmitter or neuromodulator role in the adult, because SPI structures appear in the retina before establishment of synaptogenesis and in the cornea and uvea during the fetal stage.

Chronic ocular ischemia associated with the Eisenmenger's syndrome.

We studied the ocular findings of two adult patients with the Eisenmenger's syndrome who had atrial septal defects that were diagnosed before the age of 10 years but not operated on and pulmonary hypertension. Both eyes of these patients showed microaneurysms, multiple small blot hemorrhages, or capillary dilation in the temporal peripheral fundus. Multiple microaneurysms and retinal collaterals were confirmed by fluorescein angiography. One of the patients developed bilateral rubeosis iridis with slow progression. These retinal lesions and the rubeosis iridis are probably related to chronic ocular ischemia caused by chronic systemic hypoxia.

The number of CD10-positive glomerular epithelial cells reflects renal prognosis in IgA nephropathy patients.

BACKGROUND: The glomerular epithelial cells play an important role in glomerular filtration of the kidney. The disruption of these cells contributes to the development of glomerulosclerosis. The present study was performed to elucidate whether loss of the glomerular epithelial cells is associated with renal injury in patients with IgA nephropathy. PATIENTS AND METHODS: Thirty renal biopsy specimens from IgA nephropathy, 12 from minor glomerular abnormalities and 5 from normal controls were observed. The specimens from IgA nephropathy were divided into 2 groups: Group IgA-1, including 11 patients who had received a follow-up renal biopsy because of deterioration of renal function, and Group IgA-2, consisting of the remaining 19 patients without follow-up biopsy. Immunohistochemistry was performed using a monoclonal antibody against CD10 antigen that appears on mature epithelial cells of glomeruli. RESULTS: The average number of CD10-positive glomerular epithelial cells (GECs) was significantly lower in IgA nephropathy than in either minor glomerular abnormalities or the normal controls. In IgA nephropathy, there were significant correlations of the GECs with renal functions. The GECs were reduced along with the progression of histopathological damage. In group IgA-1, the GECs were significantly reduced at the second biopsy compared with the first biopsy, and significantly fewer in group IgA-1 than in group IgA-2 at the first biopsy. The GECs showed a significant correlation with renal prognosis during the follow-up period. CONCLUSIONS: The reduction of GECs was associated with renal dysfunction, histopathological damage and renal prognosis. The GECs may be a useful predictor of renal prognosis in IgA nephropathy.

Weber-Christian disease presenting with ocular manifestations.

A Japanese patient with Weber-Christian disease (WCD) presenting with ocular symptoms is reported. Panniculitis in the retrobulbar fat was diagnosed according to the histological findings from biopsy specimens, and improved over a month under steroid administration. Only three patients showing ocular manifestations have previously been reported. Panniculitis was in the late stage and a medium dose of prednisolone was effective in this patient. A biopsy of the orbital fat was useful for diagnosis. However, it is important to recognise that the stage of inflammation varies according to the fat tissue involved by WCD.

[Isolated nuclear oculomotor nerve palsy due to mesencephalic infarction].

A patient with unilateral nuclear oculomotor palsy due to midbrain infarction is described. A 46-year-old man was admitted because of difficulty in opening right eye and double vision noticed when he awoke in that morning. On admission, neurological examination revealed total right oculomotor palsy with slight impairment of left upward gaze. There were no other neurologic abnormalities at all. Brain CT and cerebral angiograms were also normal. Magnetic resonance imaging (MRI) performed on the ninth day, however, demonstrated high signal intensity in the right tegmentum of the mesencephalon on T2-weighted images, which was shown more clearly after the administration of Gadolinium-DPTA. He was diagnosed as nuclear third nerve palsy caused by midbrain infarction. The majority of isolated oculomotor nerve palsy has been reported to be caused by extraaxial lesion. When the oculomotor palsy is caused by intraaxial ischemic lesion, it is usually accompanied by other brain stem signs, because abundant nuclei and fibers are present adjacent to the oculomotor nucleus and nerve in the mesencephalon. The present case clarified that such a small infarct disclosed only by MRI can cause isolated oculomotor nerve palsy. It is emphasized that the intraaxial ischemic lesion should be ruled out by using the sophisticated diagnostic aid before making diagnosis of peripheral lesion. This is the first report of the isolated third nerve palsy resulting from mesencephalic ischemic lesion in the Japanese.

Aldosterone-producing adrenocortical adenoma complicated by chronic renal failure. Case report and review of the literature.

A 61-year-old Japanese woman was hospitalized because of general malaise. The patient demonstrated hypertension, hypokalemia and chronic renal failure (CRF). Plasma aldosterone concentration and urinary excretion of aldosterone were elevated. Abdominal computed tomographic scan revealed right adrenal tumor and multiple cysts in both kidneys. Adrenal scintigram using 131I-adosterol disclosed uptake of the isotope in the area corresponding to the adrenal tumor. Plasma aldosterone concentration and renin activity (PRA) in an upright posture and daily variations in adrenocorticotropic hormone, cortisol, aldosterone levels and PRA were compatible with aldosterone-producing adrenocortical adenoma. After administration of spironolactone and manidipine hydrochloride, a calcium antagonist, general malaise disappeared, and blood pressure and serum potassium level returned to the normal range without adrenalectomy. Although adrenalectomy is known to be effective for the treatment of aldosterone-producing adrenocortical adenoma, several papers reporting cases of aldosterone-producing adrenocortical adenoma with CRF indicated that surgical therapy was not always optimal in terms of postoperative conditions. Taken together, the conservative therapy may be one of the choices considering the prognoses of hypertension and renal dysfunction in patients with aldosterone-producing adrenocortical adenoma with CRF.