Characterizing blood pressure control in individuals with Type 2 diabetes: the relationship between clinic and self-monitored blood pressure.

AIMS: To determine the relationship between blood pressure (BP) measurement in the clinic and self-monitored blood pressure (SMBP); and to evaluate the accuracy of self-reported data in patients with Type 2 diabetes treated intensively for hypertension. METHODS: Seventy subjects had baseline and 1-week follow-up clinic BP measured using an Omron 907 automated device. During a contemporaneous 14-day period these subjects measured their BP at least four times each day using an Omron IC semiautomatic portable monitor which, unknown to them, contained an onboard memory capable of storing BP with corresponding time and date. RESULTS: There was no significant difference between mean clinic and mean self-monitored BP. Correlations between clinic BP and SMBP were r=0.61 (P<0.0001) for systolic BP and r=0.69 (P<0.0001) for diastolic BP. Clinic BP classified 56 subjects as uncontrolled hypertension (BP > or = 130/80 mmHg, adjusted for diabetes) and 14 subjects as controlled hypertension. Using World Health Organization-International Society of Hypertension criteria for SMBP (> or = 125/75 mmHg), 55 cases of clinic classified uncontrolled hypertension were confirmed, resulting in 98% sensitivity. Clinic and SMBP agreed in one case of controlled hypertension, resulting in 7% specificity. For all subjects, the median percent of values exceeding SMBP criteria for controlled hypertension was systolic 92% and diastolic 70%. Self-reporting precision averaged 89+/-10% (range 45-100%); under-reporting was 25+/-16% (ranging from 0 to 56%) and over-reporting was 12+/-15% (ranging from 0 to 46%). The overall logbook mean was not significantly different from the downloaded data from the Omron IC(R) monitors. CONCLUSIONS: SMBP was able to identify 13 patients with uncontrolled hypertension who, by clinic BP measurement, had been classified as controlled.

Synthesis and processing of genetically modified human proinsulin by rat myoblast primary cultures.

Rat myoblast primary cultures were tested as a model for proinsulin synthesis and processing and unregulated insulin delivery for insulin-dependent diabetes mellitus (IDDM) gene therapy. Three human proinsulin cDNA constructs containing genetically engineered furin endoprotease cleavage sites between the B-chain and C-peptide (IFur) and between the C-peptide and A-chain (IIFur) and/or containing a histidine B10 to aspartic acid point mutation were subcloned into a mammalian expression vector (pCMV) containing the cytomegalovirus (CMV) promoter. The altered cleavage sites enable the insulin to be processed by the ubiquitous endoprotease furin. The histidine B10 to aspartic acid mutation creates a more stable form of insulin leading to an increase in insulin accumulation. Myoblasts transfected with a proinsulin cDNA construct mutated at all three sites (pCMV.IFur.IIFur.B10), a construct with only the furin sites (pCMV.IFur.IIFur), and a construct containing only the mutation at the B10 position (pCMV.B10) accumulated 852 +/- 16, 150 +/- 13, and 883 +/- 39 microU (pro)insulin/ml, respectively, in the culture medium during a 48-hr incubation. (Pro)insulin was detected in the culture medium within 2 hr post-transfection. Significant (pro)insulin release continued for 1 week and gradually diminished over a month. Approximately 50% of the proinsulin released from rat myoblasts transfected with pCMV.IFur.IIFur.B10 was completely processed into mature insulin based on densitometric analysis of autoradiographs of gels containing immunoprecipitated 35S-Cys-labeled (pro)insulin. However, only a trace of the proinsulin encoded by pCMV.B10 was processed. In an isolated rat adipocyte [14C]glucose oxidation assay, insulin released from myoblasts transfected with pCMV.IFur.IIFur.B10 was active biologically, displaying more biological activity than normal human insulin. Plasmid expression was studied by transfecting myoblasts with the beta-galactosidase (beta-Gal) gene in pCMV, allowing them to divide and fuse into multinucleated myotubes, followed by staining for beta-Gal. Approximately 80% of myotubes expressed beta-Gal. The results indicate that proinsulin encoded by genetically modified proinsulin cDNA is processed into mature insulin, which is secreted at high levels, making myoblasts a viable target cell for gene therapy of IDDM.

The amino acid sequence of the pancreatic islet mitochondrial glycerol phosphate dehydrogenase is not unique and the enzyme is not thyroid or glucose responsive.

The mitochondrial glycerol phosphate dehydrogenase (mGPD) is one of several proteins that are abundant in the pancreatic islet. Hormonal and nutritional influences confer tissue-specific patterns of expression on many of these proteins and the primary amino acid sequence of these proteins in the islet often differs from those in other tissues. However, the deduced amino acid sequence of the rat islet mGPD was identical to that of testis and liver. (The islet mGPD also possesses calmodulin-like calcium-binding sequences.) Islet mGPD activity and amount of protein were not changed by culturing islets at various concentrations of the insulin secretagogues, glucose, leucine, glutamine, or methyl succinate, which are conditions that alter the amounts of other enzymes in the islet. Unlike mGPD in tissues, such as liver, where mGPD activity is low, the high amount of islet mGPD was not further induced in hyperthyroid rats or by adding T3 to cultured islets or rat insulinoma cells. This suggests that the islet mGPD is under different regulation than the enzyme in tissues where its activity is low.

Genomic organization and promoter sequence of a gene encoding a rat liver-specific type-I transport protein.

We report the isolation and characterization of a rat gene (designated TI-LTP) encoding a liver-specific cell-surface glycoprotein that belongs to the type-I transporter family. This gene, including 5' and 3' flanking domains, was cloned from a rat lambda DASH genomic library and its nucleotide sequence was determined. TI-LTP is a single-copy gene which spans over 6 kb, and contains nine introns ranging in size from 90 bp to over 1.8 kb. Two transcription start points were located using a nuclease S-1 protection assay. The TI-LTP promoter (pTI-LTP) lacks a canonical TATA-box element, but does contain five TAGA elements. Several putative transcription-factor-binding sites were identified in the pTI-LTP, including activator protein 2 (AP-2) sites and a peroxisome proliferator response element (PPRE).

The sequence of a human mitochondrial glycerol-3-phosphate dehydrogenase-encoding cDNA.

A 2618-bp cDNA that encodes the human mitochondrial glycerol-3-phosphate dehydrogenase has been isolated from a HeLa cell cDNA library and the nucleotide sequence determined. An open reading frame encodes a protein of 727 amino acids that is 96% similar to the rat protein and, like the rat protein, contains sites homologous to the Ca(2+)-binding sites of calmodulin, as well as FAD- and putative glycerol-phosphate-binding sites.

Molecular cloning and characterization of a novel liver-specific transport protein.

Monoclonal antibodies that specifically recognize a membrane component located on the sinusoidal domain of the hepatocyte have been used to screen a rat liver cDNA expression library and a clone encoding a novel transporter (NLT) protein has been identified. Analysis of the deduced 535 amino acid protein sequence indicates that it is unique, but shares the twelve-transmembrane domain hydrophathicity profile as well as the presence of transporter-specific amino acid motifs with bacterial and mammalian transporters. Since overall homology of NLT to known transporter genes is low (20-25% identity) it may represent a new subgroup within the transporter family of proteins. The NLT was characterized further with respect to its tissue distribution and its expression during liver development. A 2.1 kb transcript has been found in liver and at lower levels in kidney, but not in several other tissues tested. Studies on the developing liver indicate that NLT transcripts are present at a very low level from 19 through 21 gestation days with a 4- to 5-fold increase within two weeks after birth. Overall, we have cloned a novel transporter that is preferentially expressed in liver, is located on the sinusoidal domain of the plasma membrane and represents a marker for the late stage of liver development.