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C Kent

Publications and source records attributed to C Kent.

At least 91 records · Page 5Linked to original sources
PubMed1994

Differential expression of GAP-43 mRNA in adult central cholinergic neuronal populations.

The present study addresses a question of differential expression for a 'plasticity' gene within neurons identified by neurotransmitter type. A method combining immunohistochemical localization of choline acetyltransferase (ChAT) with in situ hybridization histochemistry (ISHH) in the same brain sections was used to quantitate the levels of mRNA for the growth-associated protein GAP-43 (neuromodulin) in rat central cholinergic neuronal populations. We found that many cholinergic neurons in the adult rat brain express levels of GAP-43 mRNA comparable to other brain regions noted for their expression of this plasticity gene. GAP-43 expression in cholinergic cell groups appeared to be highly heterogeneous; this was often true even for cholinergic neurons within the same brain region. A dorsal-ventral gradient in GAP-43 mRNA levels was evident in the rostral basal forebrain cholinergic groups; i.e., medial septum, nucleus basalis magnocellularis and the vertical limb of the diagonal band expressed intermediate levels, while the horizontal limb of the diagonal band and the substantia innominata expressed higher levels of GAP-43 mRNA. Cholinergic interneurons of the striatum were grouped in several populations according to mRNA levels, from very low to very high expression. Similarly, GAP-43 mRNA levels in the cholinergic neurons of the nucleus basalis magnocellularis/substantia innominata were quite variable. The expression of GAP-43 mRNA in brainstem cholinergic groups (laterodorsal tegmental and pedunculopontine nuclei) was in nearly uniform populations of somewhat lower levels. While the expression of GAP-43 mRNA in cholinergic neurons was heterogeneous, virtually every ChAT-positive neuron sampled contained GAP-43 mRNA at levels significantly over background.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗
PubMed1994

Complex branch renovascular disease: management options and late results.

PURPOSE: The purpose of this report is to review management options and late results of complex renovascular disease managed over the last 22 years. METHODS: Complex branch renal artery disease in 84 kidneys was repaired during 75 operations performed in 68 consecutive patients. There were 61 females (90%) and 7 males (10%) whose predominant pathologic diagnosis was fibromuscular dysplasia manifesting as either renovascular hypertension or aneurysmal degeneration. These patients underwent 15 in situ, 52 ex vivo, and 8 combined reconstructions. In situ repair primarily with use of the bifurcated internal iliac artery autograft was used for primary lesions of the proximal renal artery bifurcation (two branches). Ex vivo repairs, primarily with use of the multibranch internal iliac autograft and hypothermic perfusion preservation, were used for all other patterns of distal renal artery branch disease and reoperative problems. RESULTS: Renovascular reconstruction was successful in salvaging 83 of 84 kidneys (98.8%) in 67 of 68 patients. There were no operative deaths. Two reconstructions thrombosed in the early postoperative period. One was due to severe aortic disease, the other to branch artery dissection after a failed balloon angioplasty. Both patients continued to have hypertension. Before hospital discharge 65 patients had 81 renal revascularizations proven patent by arteriography. Their renal function was assessed and blood pressure was determined in a follow-up extending to 20 years (mean 7.5 years, median 7.9 years). Late arteriograms were obtained in 30 patients (46%) an average of 52 months after operation (range 6 months to 18 years). They demonstrate stable renal artery repair with no evidence of late graft failure in each. Hypertension was cured or improved in 51 of 53 patients (96%) with a proven patent reconstruction. Aneurysms were successfully repaired in 11 patients. Renal function was improved in four patients with ex vivo repairs, unchanged in 59 patients (15 in situ, 44 ex vivo), and persistently worse in only three patients, all of whom had in situ repairs. CONCLUSION: The branched arterial autograft allows the restoration of normal renal arterial anatomy and function when inserted to replace complex distal renovascular disease. This provides a durable repair, essential for younger patients affected by this pattern of disease who anticipate a normal life span after renovascular repair. Successful long-term correction of diastolic hypertension and aneurysmal disease was accomplished without significant morbidity.

Adolescent↗
PubMed1993

Expression, purification, and characterization of CTP:glycerol-3-phosphate cytidylyltransferase from Bacillus subtilis.

Bacillus subtilis contains the gene for CTP:glycerol-3-phosphate cytidylyltransferase, which is involved in biosynthesis of the major teichoic acid of the B. subtilis cell wall. When this gene was expressed in Escherichia coli under the control of the T7 promoter, the glycerol-3-phosphate cytidylyltransferase accumulated to a level of about 15% of cellular protein. The expressed glycerol-3-phosphate cytidylyltransferase was purified to homogeneity by ion-exchange chromatography, gel filtration, and affinity chromatography on blue Sepharose. Approximately 47 mg of pure enzyme was obtained from a 660-ml culture. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that the subunit molecular weight of the purified enzyme was about 15,000. The molecular weight of the native enzyme was found to be 30,900 by gel filtration analysis, suggesting that the native enzyme is a homodimer. The pH optimum was very broad, from 6.5 to 9.5, and the enzyme was stable at alkaline conditions. A divalent cation, either Co2+, Mg2+, Mn2+, or Fe2+, was required for enzyme activity. Km values for CTP and glycerol 3-phosphate were 3.85 and 3.23 mM, respectively, and the Vmax was 185 units/mg of protein. Initial rate studies and product inhibition patterns indicated that the enzyme catalyzes the reaction by means of a rapid eqilibrium random order mechanism. The availability of large amounts of glycerol-3-phosphate cytidylyltransferase will facilitate enzymological and structural studies on this model cytidylyltransferase.

Amino Acid Sequence↗