Cyclosporine and tacrolimus alter renin-angiotesin system in mouse medullary-thick ascending limb cultured cells.
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Animals↗
Biomedical subjects
C Yang
Publications and source records attributed to C Yang.
Intracellular mechanisms of constriction of rat aorta by ethanol.
The intracellular mechanisms mediating vasoconstriction by ethanol are poorly understood. This investigation was designed to provide evidence on the role of protein kinase C (PKC) and calmodulin in vasoconstriction by ethanol. We studied helically cut strips of rat aorta that were exposed to ethanol before and in the presence of the PKC inhibitors calphostin C (79, 239, and 798 nM) or 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H7, 10 microM), and the calmodulin inhibitor, trifluoperazine (TFP, 10 microM). To test for the specificity of the PKC inhibitors, we measured the responses of aortas to potassium and phorbol 12-myristate 13-acetate (PMA) in the absence and presence of calphostin C and H7. To test for the specificity of TFP, we measured the responses of aortas to serotonin, potassium, PMA, and the thromboxane A2 mimic. 9,11-dideoxy-11 alpha, 9 alpha-epoxy-methanoprostaglandin F2a (U46619), in the absence and presence of TFP. We also studied the effect of the combination of calphostin C and TFP on constriction of the aorta by ethanol. We also measured the importance of intracellular and extracellular calcium in constriction of the aorta by ethanol. Force generation was measured before, and then during exposure of the strips to calcium-free buffer with EGTA, or calcium-free buffer with EGTA plus caffeine. We found that both PKC inhibitors antagonized vasoconstriction by ethanol and PMA. However, H7 antagonized contractions by potassium, but calphostin C did not. We found that TFP caused 99 +/- 1% inhibition of maximum contraction to serotonin, 90 +/- 4% inhibition of maximum contraction to potassium, 63 +/- 6% inhibition of maximum contraction to PMA, and 8 +/- 5% inhibition of maximum contraction to U46619. TFP caused a 22 +/- 8% inhibition of contraction to ethanol. The combination of TFP and calphostin C antagonized vasoconstriction by ethanol to a degree similar to that of calphostin C alone. We also found that contractions to ethanol were only 16 +/- 7% of control values in a calcium-free plus EGTA buffer. Contractions to ethanol were 0 +/- 1% of control values in calcium-free buffer with EGTA plus caffeine. We conclude that: 1-vasoconstriction by ethanol is, at least in part, mediated by PKC; 2-constriction by ethanol is mediated to a minimal extent by calmodulin, and 3-part of the constriction by ethanol of the aorta is mediated by a caffeine-sensitive pool of intracellular calcium.
1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
Immunomagnetic isolation of islets from the rat pancreas.
Islets were selectively isolated from rat pancreatic digests using magnetic microspheres coated with anti-islet monoclonal antibodies. The isolation process was optimized as a function of bead concentration and time of incubation with the tissue digest. Apparent and normalized islet yields of 92 +/- 6% and 81 +/- 7%, respectively, were obtained by incubating the digests with 10(7) beads/mL for 40 min followed by isolation of the bead-coated islets under a magnetic field. While some fragmentation occurred, the isolation process did not alter islet functionality as demonstrated by an insulin secretion response to glucose stimulation equivalent to that of handpicked controls. The technique is fast, reproducible, and potentially scaleable to larger pancreases as a secondary purification step.
Animals↗
Base sequence-dependent bends in site-specific benzo[a]pyrene diol epoxide-modified oligonucleotide duplexes.
The site specifically modified oligonucleotides 5'-d(TCCTCCTG1G2CCTCTC) (I) and 5'-d(CTATG1G2G3TATC) (II) were synthesized with single modified guanine residues at positions G1, G2, or G3, derived from the covalent binding reaction of 7R,8S-dihydroxy-9S,10R-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene ((+)-anti-BPDE) with the exocyclic amino groups of the guanine residues. In denaturing 20% polyacrylamide gels, the electrophoretic mobilities of the (+)-anti-BPDE-modified oligonucleotides I and II are slower than the mobilities of the respective unmodified oligonucleotides and independent of the positions of the BPDE-modified guanines. However, in the double-stranded forms in native 8% polyacrylamide gels, the electrophoretic mobilities of the duplexes with lesions at G2 or G3 are remarkably slower (reductions in mobilities up to approximately 40%) than to duplexes with lesions at G1 and are attributed to physical bends or flexible hinge joints at the sites of the BPDE lesions. These sequence-dependent mobility effects occur whenever the BPDE-modified guanine residues with (+)-trans-stereochemistry are flanked by unmodified G's on the 5'-side. These retarded electrophoretic mobilities are attributed to bending induced by steric hindrance effects involving the bulky 5'-flanking guanines and the pyrenyl residues that are known to point into the 5'-direction relative to the modified G [Cosman, M., et al. (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 1914-1918]. These anomalous electrophoretic mobility effects are not observed in the case of (-)-anti-BPDE-modified sequences I with trans-(-)-anti-BPDE-N2-dG adduct stereochemistry.
7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
Evoked cavernous activity: measuring penile autonomic innervation following pelvic surgery.
To assess cavernous nerve integrity, we measured evoked cavernous activity (ECA) in 16 men who underwent nerve sparing radical prostatectomy (NS group) and 11 men who underwent non-nerve-sparing surgery (non-NS group). The right median nerve was electrically stimulated and ECA was recorded with two concentric electromyography needles placed into the right and left cavernous bodies. We simultaneously recorded hand and foot sympathetic skin responses (SSRs) as controls. All subjects had recordable SSR, and all subjects following nerve-sparing radical prostatectomy had reproducible ECA. Of the 11 non-NS subjects, eight had no response, indicating interrupted corporal innervation. Three subjects had reproducible ECA, one of whom had a very late latency, suggesting residual innervation was present. The mean latencies of ECA were similar to foot SSR mean latencies (P>0.05), but not to hand SSR latencies. The non-NS group was significantly different from the NS group for the presence of ECA (P<0.001). ECA is a viable method of evaluating the autonomic innervation of the penis.
Aged↗
Polyester arterial prostheses. Recent developments from the Czech Republic and Poland.
To evaluate recent developments in the design and production of polyester vascular prostheses in eastern Europe, a series of in vitro physical and chemical tests and an in vivo study was performed on three new prototype devices from the Czech Republic and one from Poland. The in vitro results for these four prostheses, referred to as the Ra-1n (warp knitted, uncrimped), Ra-1v (warp knitted, crimped), Mikrofroté (weft knitted, uncrimped), and Dallon (warp knitted, crimped) prostheses, were compared against values for three commercial devices of western origin, namely the Triaxial, the Vasculour II, and the Cooley II grafts. The animal trial involved implanting the four prototype devices as a thoracoabdominal bypass in dogs for eight different periods ranging from 4 hrs to 6 months and undertaking histologic and structural investigations on the retrieved grafts. Because of its poor long-term dimensional stability in vivo, the continued use of a weft knitted structure, like the Mikrofroté prosthesis, is to be deprecated. Conversely, the introduction of a more dimensionally stable warp knitted structure in three prototypes is to be acknowledged. However, the presence of surface contaminants was most likely responsible for the excessive inflammatory reaction generated by all four prostheses during the first month in vivo, which resulted in delayed healing performance. In addition, an unusually high surface carbon-oxygen ratio suggests that the crimping process needs further refinement. Improved cleaning and packaging procedures are essential before these products can complete against existing commercial prostheses of western origin. In conclusion, these new developments illustrate that the technology of warp knitting, which is now spreading worldwide, should be evaluated.
Animals↗
Bony abnormalities of the paranasal sinuses in patients with Wegener's granulomatosis.
Wegener's granulomatosis is a systemic vasculitis that can affect any organ system, but primarily involves the upper and lower respiratory tracts and the kidneys. Chronic sinusitis is a well-known clinical feature of the disease. Mucosal abnormalities of the nose and paranasal sinuses have been well-characterized and range from granulomatous lesions to diffuse mucosal thickening. In contrast, abnormalities of the underlying bone of the paranasal sinuses in this disease have not been well-described, and reports have been limited. To characterize bony abnormalities of the nose and paranasal sinuses in patients with Wegener's granulomatosis, we performed a retrospective review of all patients with Wegener's granulomatosis who underwent a sinus CT scan at our institution between 1989 and 1999. Nine patients were identified. A total of 22 distinct bony abnormalities were identified in 5 patients. Specific bony findings included bony erosion and destruction of the septum and turbinates; erosion of the ethmoid sinuses; neo-osteogenesis of the maxillary, frontal, and sphenoid sinuses; and complete bony obliteration of the maxillary, frontal, and sphenoid sinuses. Although these findings are suggestive of Wegener's granulomatosis, they are not pathognomonic. Bony changes on sinus CT scan may provide radiologic evidence of underlying Wegener's granulomatosis when clinical suspicion is high.
Adult↗
Differentiating human from animal isolates of Cryptosporidium parvum.
We analyzed 92 Cryptosporidium parvum isolates from humans and animals by a polymerase chain reaction/restriction fragment length polymorphism method based on the thrombospondin-related anonymous protein 2 gene sequence. Used as a molecular marker, this method can differentiate between the two genotypes of C. parvum and elucidate the transmission of infection to humans.
Animals↗
Dynamic contrast-enhanced T2*-weighted MR imaging of tumefactive demyelinating lesions.
PURPOSE: Dynamic contrast-enhanced T2*-weighted MR imaging has been helpful in characterizing intracranial mass lesions by providing information on vascularity. Tumefactive demyelinating lesions (TDLs) can mimic intracranial neoplasms on conventional MR images, can be difficult to diagnose, and often result in surgical biopsy for suspected tumor. The purpose of this study was to determine whether dynamic contrast-enhanced T2*-weighted MR imaging can be used to distinguish between TDLs and intracranial neoplasms that share common features on conventional MR images. METHODS: We retrospectively reviewed the conventional and dynamic contrast-enhanced T2*-weighted MR images and medical records of 10 patients with tumefactive demyelinating disease that was diagnosed by either biopsy or strong clinical suspicion supported by laboratory evaluation that included CSF analysis and evoked potential tests. Twelve TDLs in 10 patients and 11 brain tumors that appeared similar on conventional MR images were studied. Relative cerebral blood volume (rCBV) was calculated from dynamic MR data and was expressed as a ratio to contralateral normal white matter. rCBV values from 11 patients with intracranial neoplasms with very similar conventional MR imaging features were used for comparison. RESULTS: The rCBV values of TDLs ranged from 0.22 to 1.79 (n = 12), with a mean of 0.88 +/- 0.46 (SD). The rCBV values of intracranial neoplasms ranged from 1.55 to 19.20 (n = 11), with a mean of 6.47 +/- 6.52. The difference in rCBV values between the two groups was statistically significant (P =.009). The difference in rCBV values between TDLs and primary cerebral lymphomas (n = 4) was less pronounced but was statistically significant (P =.005). CONCLUSION: Dynamic contrast-enhanced T2*-weighted MR imaging is a useful diagnostic tool in differentiating TDLs from intracranial neoplasms and may therefore obviate unnecessary surgical biopsy.
Adolescent↗
Ethical decision making in assisted suicide.
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American Nurses' Association↗
Effect of energy restriction on riboflavin retention in normal and deficient tissues of the rat.
We investigated the effects of energy restriction on tissue riboflavin depletion and subsequent repletion of deficient tissues. Groups of male Sprague Dawley rats with average body weights between 268 and 275g were placed on energy-restricted diets consisting of 8g (31kcal or 130kJ) per day of a basal diet adequate in all other nutrients and either 12mg of riboflavin/kg or no added riboflavin. The ad libitum controls received additional energy as a mixture of sucrose, starch, and corn oil (10:3:1 by wt). No significant difference in the degree of riboflavin deficiency was detected between energy-restricted and ad libitum-fed rats as assessed by riboflavin concentrations in the liver and gastrocnemius and soleus muscles and by the erythrocyte glutathione reductase activity coefficient (EGRAC). Additional energy-restricted riboflavin-deficient rats were subsequently repleted by feeding either the supplemented basal diet with no additional energy or with ad libitum energy. Repletion of liver riboflavin concentration and reduction of the EGRAC values to control levels occurred regardless of energy intake. Muscle riboflavin concentrations were normal in the ad libitum-fed group but decreased in the energy-restricted rats despite 4 weeks of supplementation. The latter group had muscle riboflavin levels similar to those in the rats fed the riboflavin-deficient diet for 8 weeks. The results suggest that energy restriction impairs flavo-protein synthesis in muscle but not in the liver.
Animals↗
Use of restraints in the elderly in long term care facilities.
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Aged↗