Hemodynamic, hormonal, and renal effects of intracerebroventricular adrenomedullin in conscious sheep

Adrenomedullin, the recently described vasodilator that exhibits potent hypotensive actions when administered systemically, is also found in the central nervous system, suggesting a role for adrenomedullin as a neurohormone. However, only a limited number of studies have examined the central effects of adrenomedullin. Therefore, we have examined the integrative hemodynamic, renal, and hormonal effects of intracerebroventricular (I.C.V.) adrenomedullin in conscious sheep. Eight surgically prepared sheep received I.C.V. infusions of adrenomedullin at two doses (2 ng/kg x min followed immediately by 20 ng/kg x min each for 90 min) in a vehicle-controlled study. Water deprivation for 48 h before control infusion resulted in sheep drinking 2617 +/- 583 ml in the 90-min period following reintroduction of water. On the adrenomedullin day, drinking was halved to 1392 +/- 361 ml (P < 0.05). Adrenomedullin had no significant effect on urinary volume and sodium excretion. Plasma adrenomedullin levels remained unchanged during control infusions but were elevated by the end of I.C.V. adrenomedullin infusions (P < 0.001). Plasma ANP levels were also increased approximately 50% (P < 0.05). Plasma levels of both ACTH and cortisol were also increased 3- to 4-fold in response to I.C.V. adrenomedullin (P < 0.05). There was no significant difference in arterial pressure, heart rate, or cardiac output between study days. In conclusion, adrenomedullin within the central nervous system may have at least two roles: modulation of the hypothalamo-pituitary-adrenal axis and protection against fluid overload.     

Variations of bacterial populations in human feces measured by fluorescent in situ hybridization with group-specific 16S rRNA-targeted oligonucleotide probes

Six 16S rRNA-targeted oligonucleotide probes were designed, validated, and used to quantify predominant groups of anaerobic bacteria in human fecal samples. A set of two probes was specific for species of the Bacteroides fragilis group and the species Bacteroides distasonis. Two others were designed to detect species of the Clostridium histolyticum and the Clostridium lituseburense groups. Another probe was designed for the genera Streptococcus and Lactococcus, and the final probe was designed for the species of the Clostridium coccoides-Eubacterium rectale group. The temperature of dissociation of each of the probes was determined. The specificities of the probes for a collection of target and reference organisms were tested by dot blot hybridization and fluorescent in situ hybridization (FISH). The new probes were used in initial FISH experiments to enumerate human fecal bacteria. The combination of the two Bacteroides-specific probes detected a mean of 5.4 x 10(10) cells per g (dry weight) of feces; the Clostridium coccoides-Eubacterium rectale group-specific probe detected a mean of 7.2 x 10(10) cells per g (dry weight) of feces. The Clostridium histolyticum, Clostridium lituseburense, and Streptococcus-Lactococcus group-specific probes detected only numbers of cells ranging from 1 x 10(7) to 7 x 10(8) per g (dry weight) of feces. Three of the newly designed probes and three additional probes were used in further FISH experiments to study the fecal flora composition of nine volunteers over a period of 8 months. The combination of probes was able to detect at least two-thirds of the fecal flora. The normal biological variations within the fecal populations of the volunteers were determined and indicated that these variations should be considered when evaluating the effects of agents modulating the flora.     

Growth factor regulation of insulin-like growth factor (IGF) binding proteins (IGFBP) and preadipocyte differentiation in porcine stromal-vascular cell cultures

The influence of anti-IGF-1 and anti-transforming growth factor beta (TGF-beta) neutralizing antibodies on preadipocyte differentiation and secretion of IGFBPs was examined in serum free porcine stromal-vascular cultures. Cultures were stained for morphological analysis and conditioned media were collected for: TGF-beta determination by ELISA, IGF-1 by RIA, and IGFBP analysis by ligand blotting. After 6 d of treatment, anti-TGF-beta increased fat proportions by 2.7 fold compared to controls. Anti-IGF-1 decreased fat cell proportions by 14-fold. Anti-TGF-beta increased concentrations of IGF-1 5.8-fold and IGFBP-2 and IGFBP-3 by 8- and 7-fold in conditioned media whereas IGFBP-4 decreased 5-fold. Anti-IGF-1 increased concentrations of IGFBP-2 and 3 by 9- and 35-fold, respectively. TGF-beta increased concentrations of IGFBP-1, 2 and 3 by 3-fold, 18-fold and 3-fold, respectively, after 9 d in culture (6 d of treatment). There was no change in TGF-beta levels in anti-IGF-1 treated cultures compared to controls. Control antibodies and negative controls had no effect. These results provide evidence that endogenously produced IGF-1 and TGF-beta has a major influence on preadipocyte differentiation in serum free media by modulating IGFBP production/secretion.     

Cloning and overexpression of rhamnose isomerase and fucose isomerase

Rhamnose isomerase and fucose isomerase were overexpressed in E. coli, purified and characterized. The rhamnose isomerase gene was ligated to the restriction sites of PstI and Hind III of vector pTrcHis and the fucose isomerase gene was ligated to the EcoRI and PstI sites of vector pKK223-3 for overexpression of the enzymes in E. coli XL1-Blue MRF. Approximately 16,500 U of active fucose isomerase and 2400 of rhamnose isomerase can be obtained per liter of culture from these expression systems.     

Organ injury scaling: spleen and liver (1994 revision)

A case of haemangiopericytoma of the greater omentum is reported here. We discuss the presentation, treatment and prognosis of these rare tumours.