Relationships between apolipoprotein(a) phenotype and increase of lipoprotein(a) by troglitazone

Troglitazone is a new oral hypoglycemic agent that reduces insulin resistance in non-insulin-dependent diabetes mellitus (NIDDM). However, this agent increases serum lipoprotein(a) [Lp(a)], which is known as an atherogenic lipoprotein. The relationships between the response of Lp(a) to troglitazone and the apolipoprotein(a) [apo(a)] phenotype were investigated in this study. Nineteen NIDDM patients were treated with troglitazone for 4 weeks. Lp(a) increased significantly from 20.1+/-16.5 mg/dL to 44.1+/-31.9 mg/dL (P<.001) in all study patients. Lp(a) increased from 25.7+/-34.2 mg/dL to 50.1+/-38.7 mg/dL (P = .03) in patients with smaller apo(a) phenotypes (S1S4 to S2S4). Lp(a) also increased from 17.5+/-12.0 mg/dL to 41.3+/-29.6 mg/dL (P<.01) in patients with larger apo(a) phenotypes (S3 to S4). Therefore, the increase of Lp(a) by troglitazone may be independent of the apo(a) phenotype.

[Epidemiological study for infection with H. pylori in Japan compared with that in USA, Europe and Asian Pacific area]

The prevalence of infection with H. pylori in developed countries was about 20%, on the other hand in developing countries it reached over 80%. In developed countries 40% of infants already had anti-H. pylori antibody and the prevalence of infection rapidly increased and then reached the peak (80%) in teenager. In contrast in developed countries the rate of infection with H. pylori was below 20% in teenager and gradually increased by age (1% per 1 year). In our country an unique pattern of the prevalence of infection with H. pylori was observed. The rate of infection with H. pylori in young person was low and increased with 1% per 1 year (developed countries pattern). However, middle-aged person had higher rate of infection of H. pylori (over 85%) (developing countries pattern). These results suggested H. pylori infection would be closely associated with childhood living conditions than current living (including socioeconomic) status. From this point of view, the prevention for infection with H. pylori in childhood will be most important to prevent the gastroduodenal disease related with H. pylori in the future.

Stepwise ethanolysis of tuna oil using immobilized Candida antarctica lipase

Ethanolysis of fish oil under mild conditions has been strongly desired for preparing the starting materials for the purification of ethyl docosahexaenoate. Thus, we attempted ethanolysis of tuna oil using immobilized Candida antarctica lipase. The immobilized lipase was inactivated in the presence of 2 3 molar equivalent of ethanol against the total fatty acids in tuna oil. To avoid such inactivation, the first step of ethanolysis was conducted at 40 degrees C in a mixture of tuna oil and 1 3 molar equivalent of ethanol using 4% immobilized lipase. After a 10-h reaction, ethanol was consumed and 33% of tuna oil was converted to its corresponding ethyl esters (E-FAs). The reactant is named Gly/E-FA33. The lipase was not inactivated in the presence of 2 3 molar equivalent of ethanol against the total fatty acids in Gly/E-FA33. These findings and the consideration of several factors affecting ethanolysis of tuna oil led to the development of the two- and three-step ethanolyses. The two-step reaction was performed as follows: the first step was carried out at 40 degrees C for 12 h in a mixture of tuna oil and 1 3 molar equivalent of ethanol with 4% immobilized lipase; the second step was performed for 36 h (total reaction period, 48 h) after adding 2 3 molar equivalent of ethanol. On the other hand, the three-step reaction was conducted as follows: the first step was conducted under the same conditions as those in the two-step ethanolysis; in the second and third steps, 1 3 molar equivalent of ethanol was added after 12 and 24 h, respectively; and in the third step, the mixture was shaken for 24 h (total, 48 h). Both types of ethanolyses achieved the conversion of 95% or more of tuna oil to its corresponding E-FAs. To investigate the lipase stability, the two- and three-step ethanolyses were repeated by transferring the enzyme to a fresh substrate mixture of the first step after finishing one cycle of reaction. The two- and three-step reactions maintained over 95% of the conversion for 70 d and over 100 d, respectively.

Structure of the murine secretory leukoprotease inhibitor (Slpi) gene and chromosomal localization of the human and murine SLPI genes

Secretory leukoprotease inhibitor (SLPI) is a serine protease inhibitor involved in antineutrophil elastase protection at inflammatory sites. To elucidate both the function and regulation of SLPI in vivo, we isolated and characterized the mouse Slpi gene. An entire 3-kb mouse Slpi gene fragment was sequenced, including an 0. 8-kb 5'-flanking region, the 2.2-kb Slpi gene, and a 0.1-kb 3'-flanking region. The mouse Slpi gene spans 2,222 base pairs containing four exons and three introns. All splicing borders between exons and introns are conserved as predicted by GT-AG rules. Using primer extension analysis, the transcription start site was located 20 nucleotides upstream from the methionine (ATG) initiation codon. At the defined transcription start site, the sequence TCA+1GAGC is present. These results indicate that both mouse and human genomic structure are highly conserved. Using fluorescence in situ hybridization, we confirmed that, consistent with the genomic similarity, the human SLPI gene is localized on chromosome 20q12-13. 2 and the mouse homologue on chromosome 2H, which are syntenic with each other.

C-terminal peptide of fusarium heterosporum lipase is necessary for its increasing thermostability

Saccharomyces cerevisiae bearing a lipase cDNA from Fusarium heterosporum produced two lipases, A and B. Lipase B was significantly more stable to temperature than lipase A, but their optimum temperatures were similar. Lipase B was composed of one polypeptide (301 amino acids), and lipase A was composed of two polypeptides (275 and 26 amino acids) generated by the cleavage between Arg275 and Asp276 with a trypsin-like protease. It was suggested that the C-terminal peptide (26 amino acids) tightened the lipase structure when bound to the catalytic domain (275 amino acids) through a peptide bond. The tight structure was loosened by cleavage of the C-terminal peptide, even though the peptide interacted noncovalently with the catalytic domain, possibly through charged amino acids, in which it is rich. Deletion of the C-terminal peptide greatly decreased the lipase production by the recombinant S. cerevisiae, although its transcriptional level was the same as that of cells carrying the wild-type gene. These facts suggested that the C-terminal peptide affected the lipase production in the post-transcriptional step.

Removal of low-density lipoprotein from plasma by adsorption increases bradykinin and plasma nitric oxide levels in patients with peripheral atherosclerosis

Low-density lipoprotein (LDL) adsorption using a dextran sulfate cellulose column is brought about by electrostatic binding between the positive charges of apolipoprotein B in LDL and the negative charges of dextran sulfate cellulose. There is general agreement that the initial contact phase in the coagulation pathway may be activated by a negatively charged surface such as dextran sulfate cellulose, resulting in the generation of bradykinin. We investigated whether the increase in the generation of bradykinin during LDL adsorption is accompanied by the activation of endogenous production of nitric oxide (NO) in patients with peripheral atherosclerosis. LDL adsorption therapy was repeated ten times over a period of 3 months in ten peripheral atherosclerosis patients. Treatment significantly reduced serum total cholesterol and LDL cholesterol levels. This was associated with a significant improvement in Fontaine's classification and ankle pressure index. We also measured the kinin-kallikrein system and plasma levels of NO in the same patients. The results showed that coagulation factors of the intrinsic pathway including high-molecular-weight kininogen and prekallikrein decreased markedly after initial adsorption compared with the levels before treatment. There was a marked increase in bradykinin and NO concentrations after the initial adsorption, compared with their levels before adsorption. Our results suggest that the generation of bradykinin and increased plasma levels of NO may contribute to the improvement in peripheral circulation after LDL adsorption in peripheral atherosclerosis patients.

Affinity and kinetic analysis of the molecular interaction of ICAM-1 and leukocyte function-associated antigen-1

LFA-1 is a member of the beta2 integrin family, and interacts with ICAM-1, a member of the Ig superfamily containing five Ig-like domains. Interaction of LFA-1 with ICAM-1 is important in a number of cellular events, including Ag-specific T cell activation and leukocyte transendothelial migration, which are known to be typically transient and highly regulated. In this study, we have used surface plasmon resonance technology to study the ICAM-1/LFA-1 interaction at the molecular level. A soluble form of LFA-1 (sLFA-1), normally expressed as two noncovalently associated membrane-bound subunits, has been produced, and its interaction with ICAM-1 has been examined. The kinetic analysis of a monomeric sLFA-1 binding to the first two domains of ICAM-1 expressed as a chimeric IgG fusion protein (D1D2-IgG) revealed that sLFA-1 was bound to the D1D2-IgG chimera with a Kd of 500 nM and dissociated with a k(diss) of 0.1 s(-1). Monomeric membrane-bound LFA-1 purified from plasma membranes showed a similar kinetic to sLFA-1. These results suggest that the monovalent interaction between ICAM-1 and LFA-1 has a primarily high affinity and a slow dissociation rate constant as compared with other adhesion molecules, suggesting a potential mechanism for firm adhesion.

Cloning of the murine interferon-inducible protein 10 (IP-10) receptor and its specific expression in lymphoid organs

To isolate the interferon-inducible protein 10 (IP-10) receptor gene, we searched for cells that respond to IP-10. Among several human and murine T cell lines, only CTLL2 cells ( a murine cytotoxic T cell line) responded to IP-10 with transient elevation of intracellular Ca2+. The murine IP-10 receptor gene has been cloned from cDNA derived from CTLL2 cells using the reverse transcriptase-polymerase chain reaction protocol with two degenerate primers corresponding to conserved regions of chemokine receptors. The cDNA encoding the murine IP-10 receptor has an open reading frame of 1101 bp corresponding to a protein of 367 amino acids that exhibits 86 % identity with the human IP-10 receptor. It mediates Ca2+ mobilization in response to IP-10, but does not recognize other rodent chemokines, including GRO, RANTES, monocyte chemoattractant protein-1 (MCP-1), and macrophage inflammatory protein-1alpha (MIP-1alpha). Northern blot analysis revealed that murine IP-10 and its receptor mRNA were constitutively expressed in the spleen and thymus from normal mouse, while IP-10 and its receptor mRNA were derived from stromal cells and lymphocytes in both tissues, respectively. In vivo treatment with concanavalin A (Con A) for 12 hrs revealed that splenocytes significantly induce IP-10 receptor mRNA expression and show a good chemotactic response to IP-10. Therefore, it is supposed that IP-10 and its receptor are important for lymphocyte trafficking to lymphoid organs and that the IP-10 receptor on lymphocytes is rapidly inducible on inflammation or in immunological events.

Surgical significance of supernumerary parathyroid glands in renal hyperparathyroidism

In secondary hyperparathyroidism (2HPT) fundamentally all parathyroid glands, including supernumerary glands, become hyperplastic, and stimulation of parathyroid glands continues after parathyroidectomy (PTx). Therefore supernumerary glands have special significance during surgery for 2HPT, whether persistent or recurrent HPT. In the present study 570 patients underwent initial total PTx with a forearm autograft. The frequency, type, location, histopathology, and clinical significance of the supernumerary glands were evaluated. At the initial operation 90 supernumerary glands were removed from 82 to 570 patients (14.4%); 12 patients (2.1%) required extirpation of supernumerary glands for persistent/recurrent HPT. Altogether 104 supernumerary glands were identified at operation in 94 of the 570 patients (16.5%). Among these 104 glands, 25 (24.0%) were of the rudimentary, or split, type and 79 (76.0%) of the proper type. Supernumerary glands were most frequently identified in the thymic tongue (53/104, 51.0%); 32 (60.4%) of these 53 glands were identified only microscopically. In 6 of the 570 cases (1.1%), reoperation was required for persistent HPT due to supernumerary glands located in the mediastinum, and 6 patients underwent neck reexploration for recurrence. Histopathologically, 61 of 104 (58.7%) supernumerary glands, including 36 glands recognized only microscopically, showed diffuse hyperplasia, and 43 (41.3%) displayed nodular hyperplasia. Residual small supernumerary glands with diffuse hyperplasia have the potential to be transformed to nodular hyperplasia during long-term hemodialysis. Therefore all parathyroid glands including supernumerary glands should, if possible, be removed at the initial operation. Routine removal of the thymic tongue and careful examination of the regions surrounding the lower poles of the thyroid, especially on the left side, are important steps in the surgical treatment.

Double-sector Lorenz plot scattering in an R-R interval analysis of patients with chronic atrial fibrillation: incidence and characteristics of vertices of the double-sector scattering

Animal experiments have demonstrated that the minimum R-R interval during atrial fibrillation is proportional to the functional refractory period of the atrioventricular node. On Lorenz plots, atrial fibrillation is characterized by sector-shaped scattering; the vertex of the sector (ie, the minimum R-R interval) represents the functional refractory period. According to the atrioventricular nodal dual-pathway theory, it was hypothesized that the dual atrioventricular nodal pathways associated with chronic atrial fibrillation represent two vertices with two sectors. Detection of two-sector Lorenz plot scattering was attempted in 48 patients with chronic atrial fibrillation who underwent 24-hour ambulatory electrocardiography. Lorenz plot scattering was constructed by means of a computer. Two sectors, suggesting dual pathways, were detected in 19 (40%) of the 48 patients. The two vertices, located at 388 +/- 61 ms (mean +/- SD) and 580 +/- 60 ms were considered to represent the functional refractory periods of the fast and slow pathways, respectively. The vertex indicating the fast pathway showed greater circadian variation than that indicating the slow pathway. In one patient with dual-sector Lorenz plot scattering, whose atrial fibrillation spontaneously converted to sinus rhythm, an electrophysiologic study demonstrated dual atrioventricular nodal pathways. Thus, the Lorenz plot analysis identified two sectors, indicating the dual pathways, in approximately 40% of the patients with chronic atrial fibrillation, and the characteristics of the functional refractory periods of both pathways were estimated from the characteristics of the vertices. Although this study did not provide direct evidence of the dual atrioventricular nodal pathways, the analysis of Lorenz plot scattering may be clinically useful for studying the effects of drugs and/or ablation on the ventricular response in patients with atrial fibrillation based on the dual atrioventricular nodal pathway theory.

7-(2-Aminomethyl-1-azetidinyl)-4-oxoquinoline-3-carboxylic acids as potent antibacterial agents: design, synthesis, and antibacterial activity

2-Aminomethyl-1-azetidinyl, -1-pyrrolidinyl, and -1-piperidinyl groups were designed as novel C-7 substituents for potential antibacterial quinolone agents. Of the three substituents, the 2-aminomethyl-1-azetidinyl group (compound 12a) was found to be the most favorable for enhancing the activity of the 6,8-difluoroquinoline molecule 12. Therefore the 2-aminomethyl-1-azetidinyl group was introduced into a variety of quinolines (giving 24-26a, and 28a) and naphthyridines (giving 31a and 32a). Through optical resolution of 1-benzylazetidine-2-carboxamide (19) and chiral synthesis of its R-isomer, both enantiomers of 2-aminomethyl-1-azetidinyl quinolines 12a and 24-26a were also prepared. The most active of all the compounds was 5-amino-6,8-difluoroquinoline (R)-26a. The activity of (R)-26a was more potent than those of the corresponding 1-piperazinyl derivative (3) and sparfloxacin (1), and was comparable to those of the corresponding 3-amino-1-pyrrolidinyl (4), 3-aminomethyl-1-pyrrolidinyl (5), and 3-amino-1-azetidinyl (6) derivatives.

Synthesis and structure--antibacterial activity relationships of 7-(3-amino-1-propynyl and 3-amino-1-propenyl)quinolones

7-(3-Amino-1-propynyl)-1-cyclopropyl-6,8-difluoro-1,4-dihydro-4- oxoquinoline-3-carboxylic acid (7a) and some related compounds (7b-f, 8a, b, 9) were prepared via palladium(0)-catalyzed cross-coupling reaction of 7-iodoquinolone 12 with acetylenic compounds and their antibacterial activity was tested. The methylene homologue (7d) and the N-methyl derivative (7e) of 7a showed essentially the same activity as that of 7a. Addition of methyl group(s) to C'-3 of 7a (giving 7b, c) reduced the activity. The hydrogenation of 7a to (Z)-3-amino-1-propenyl (8a), (E)-3-amino-1-propenyl (8b) and 3-amino-1-propyl (9) compounds retained or enhanced the activity of 7a. Among the compounds prepared, 8a was the most active, but was less active than ciprofloxacin (1). In order to get insight into structure-activity relationships, the spatial distribution of the amino groups of 7a, 8a, b, and 9 was examined by means of computer-aided molecular modeling.

Expression of a soluble form of LFA-1 and demonstration of its binding activity with ICAM-1

The interaction between lymphocyte function-associated antigen-1 (LFA-1) and intercellular adhesion molecule-1 (ICAM-1) is of importance in a number of cellular events, including antigen-specific T cell activation and emigration of leukocytes into sites of inflammation. We describe here the first use of a recombinant soluble form of human LFA-1 (sLFA-1) for the measurement of the binding between LFA-1 and ICAM-1. sLFA-1 has been successfully expressed and purified. The expressed sLFA-1 was shown to be functionally active by their binding to ICAM-1. Binding of sLFA-1 to ICAM-1 was observed by receptor binding assay. Both monomeric (soluble ICAM-1 or the first two domains of ICAM-1) and dimeric ICAM-1 (IgG chimera of each ICAM-1 fragment) showed inhibitory activity on assay with IC50 values of 400 nM and 40 nM, respectively. These results suggest that the soluble constructs would be useful tools for molecular analysis of ICAM-1/LFA-1 interaction as well as in screening for ICAM-1/LFA-1 antagonists.

Effects of voglibose on glycemic excursions, insulin secretion, and insulin sensitivity in non-insulin-treated NIDDM patients

OBJECTIVE

To investigate the effects of voglibose, an alpha-glucosidase inhibitor, on daily glycemic excursions, insulin secretion, and insulin sensitivity in non-insulin-treated NIDDM patients.

RESEARCH DESIGN AND METHODS

An open prospective study was conducted in 27 NIDDM patients receiving diet therapy alone or treatment with a sulfonylurea drug. Of the study subjects, 14 patients were treated with voglibose; the remaining 13 patients served as the control group. The metabolic parameters were evaluated before treatment and at week 4 of treatment as follows: glycemic excursions by M-value and 1,5-anhydro-D-glucitol (1,5-AG), insulin secretion by area under the curve of daily serum insulin (AUCinsulin), and insulin sensitivity by the K index of the insulin tolerance test (KITT).

RESULTS

After the study treatment, HbA1c and plasma glucose in the patients who had received voglibose were comparable to those of patients in the control group. M-value was lower in the patients treated with voglibose than in the control subjects (5.7 +/- 0.9 vs. 9.8 +/- 1.2, P < 0.05). 1,5-AG was higher in the patients treated with voglibose than in the control subjects (12.2 +/- 1.0 vs. 8.2 +/- 0.7 micrograms/ml, P < 0.01). A statistically significant increase in AUCinsulin occurred after treatment with voglibose (2,223.5 +/- 390.6 to 1,546.7 +/- 303.4 pmol.l-1.h, P < 0.05), but no change occurred in the control group (2,364.5 +/- 315.4 to 2,464.2 +/- 269.3 pmol.l-1.h, P = 0.60). Insulin sensitivity (KITT) was improved to a statistically significant level in both the patients treated with voglibose and the patients in the control group. KITT in the patients after voglibose treatment was comparable to that of the control group (3.18 +/- 0.30 vs. 3.21 +/- 0.23%/min, P = 0.94).

CONCLUSIONS

The results suggest that voglibose lowers the daily glycemic excursions and inhibits overwork of the pancreatic beta-cells but has little effect on insulin sensitivity in NIDDM patients.

Administration of IL-4 prevents autoimmune diabetes but enhances pancreatic insulitis in NOD mice

The present study demonstrated that the administration of recombinant interleukin-4 (rIL-4) prevented overt diabetes in nonobese diabetic (NOD) mice whose T cells produced relatively low amounts of IL-4. However, massive insulitis was observed in rIL-4-treated NOD mice. The flow cytometric analysis of islet-infiltrating T cells revealed that the number of CD45RBlowCD4+ T cells was significantly increased by in vivo administration of rIL-4. By measuring the cytokine production of splenic T cells after stimulation, it was shown that CD45RBlowCD4+ T cells predominantly produced IL-4 and IL-10 but produced less IL-2 and interferon-gamma (IFN-gamma). A semiquantitative reverse-transcriptase polymerase chain reaction assay revealed a higher expression of IL-4 and IL-10 mRNA and an apparent decrease in IFN-gamma mRNA in the islets of NOD mice which were administered rIL-4. These results suggested that autoreactive CD45RBlowCD4+ T helper 2 (Th2)-like cells which developed following rIL-4 administration were predominant in the infiltrate of the islets, and overt diabetes was prevented. On the other hand, when splenocytes from rIL-4-treated NOD mice were transferred to irradiated NOD recipients, along with splenocytes from diabetic NOD mice, all of the recipient mice became diabetic within 8 weeks after transfer. Considered together, a supplement of rIL-4 administered to NOD mice may protect against autoimmune diabetes by facilitating the development of Th2-like autoreactive T cells in the islets.

Subgingival distribution of periodontopathic bacteria in adult periodontitis and their susceptibility to minocycline-HCl

The purpose of this study was to investigate the distribution of several periodontopathic bacteria in adult periodontitis, their in vitro susceptibility to minocycline-HCl, and whether the efficacy of the drug changes with a decrease in bacterial susceptibility. Twenty-one patients (43 to 75 years old) with 62 periodontal lesions from pockets > or =4 mm participated in the study. After subgingival sampling, an ointment containing 2% minocycline-HCl was applied locally to the selected pockets once a week for 4 weeks. The lesions were clinically examined after 1 and 4 weeks of administration. The distribution of the subgingival microorganisms included Capnocytophaga sputigena (37.1%), Prevotella intermedia (22.6%), Porphyromonas gingivalis (22.6%), Fusobacterium nucleatum (20.1%), Actinobacillus actinomycetemcomitans (9.7%), and Eikenella corrodens (4.8%). The distribution was complex, with 76.8% of the sites containing 1 to 3 bacterial spieces. The minimum inhibitory concentration (MIC) of minocycline-HCl for each organism showed that most were inhibited by a minocycline-HCl concentration equal to or less than the MIC for reference strains. However, some clinical strains of Prevotella intermedia seemed to exihibit low susceptibility to minocycline-HCl. There were no significant differences among sites with strains exhibiting low or normal susceptibility to minocycline-HCl. The concentration of the drug applied to deep periodontal pockets inhibited the growth of most of the microorganisms investigated in this study.

Parathyroid hormone suppression by 22-oxacalcitriol in the severe parathyroid hyperplasia

The suppression of parathyroid hormone (PTH) secretion by the administration of 1,25-dihydroxyvitamin D [1,25(OH)2D3] and 22-oxacalcitriol (OCT) was evaluated in nude mice transplanted with human hyperplastic parathyroid tissue. The parathyroid tissue was obtained for transplantation from a patient with severe secondary hyperparathyroidism who had undergone a parathyroidectomy. Tissue specimens were transplanted into the gluteus muscle of female nude mice. Animals were divided into two groups; one group was fed a normal diet, and the other group was fed a low calcium diet during the administration of OCT and 1,25(OH)2D3. OCT and 1,25(OH)2D3 were intraperitoneally administered two times every week, for a total of eight times. Serum calcium and phosphate levels were significantly higher in the mouse administered 1,25(OH)2D3 than in the mouse administered OCT. Serum alkaline phosphatase activity was elevated similarly in the mouse administered either OCT or 1,25(OH)2D3. OCT strongly suppressed human PTH secretion from the graft in mice with normal serum calcium levels as did 1,25(OH)2D3. However, human PTH secretion from the graft was stimulated by the administration of a low-calcium diet, despite OCT and 1,25(OH)2D3 administration. In summary, OCT and 1,25(OH)2D3 suppress PTH secretion even from severe secondary hyperplastic parathyroid tissue only in mice with normal or high calcium serum levels.

Telomerase activity in pancreatic juice differentiates ductal carcinoma from adenoma and pancreatitis

Telomerase activity was measured in pancreatic juice obtained by endoscopic retrograde pancreatography from 34 patients (12 with ductal carcinoma, 12 with pancreatic adenoma, and 10 with pancreatitis). The activity in pancreatic juice was expressed as the number of cells of a human pancreatic cancer cell line, MIA PaCa-2, that exhibit an activity equal to that expressed in 1 microg of protein from pancreatic juice. A telomerase ladder was detected in the pancreatic juice obtained from a majority of the patients with ductal adenocarcinoma. The median value of relative telomerase activity in the carcinoma samples was 9.38 (25th percentile, 3.14; 75th percentile, 95.8), a value significantly higher than that derived from patients with either pancreatitis or pancreatic adenoma (P < 0.0001). When a threshold value of relative telomerase activity of 3.00 was used, 75% (9 of 12) of the samples obtained from patients with ductal carcinoma were positive. We conclude that telomerase activity in pancreatic juice differentiates adenocarcinoma from adenoma and pancreatitis and may serve as a useful diagnostic tool.

Decremental oscillation curve fitting of heart rate response following face immersion into cold water

Using 18 healthy volunteers, we attempted to fit the heart rate response to a decremental oscillation curve by the least-squares method following facial immersion into cold water. The decremental oscillation equation was as follows: HR = alpha.e(-betat) sin omegat + gamma, where HR is the instantaneous heart rate at t s, alpha the maximum amplitude of the decremental oscillation, beta the decremental rate, omega the angular velocity and gamma the basal heart rate. Each subject immersed his/her face fully in a basin filled with ice-cold water (4 degrees C) for 30 s. The heart rate response to facial immersion was significantly fitted to the decremental oscillation curve with a correlation coefficient > 0.75 in all the trials. Double trials with a 15-min intertrial interval did not show any significant change in the coefficients. Atropine sulfate decreased the value of coefficient omega and increased that of gamma but did not change alpha or beta, indicating that omega is determined mainly by parasympathetic tone. There were no differences for any coefficient between men and women. The coefficients beta and gamma increased in association with age. Given the significant fitting to the decremental oscillation curve of the heart rate response, we propose that the corresponding electrical circuit consists of a resistance and an inductor connected in series, with a condenser in a parallel circuit with a direct current impulse. This method of fitting with the corresponding electric circuit may be useful for analysis of the heart rate response to physiological stimulus.

Secondary hyperparathyroidism: pathophysiology, histopathology, and medical and surgical management

It is generally accepted that morphological changes of the parathyroid glands appear early in renal failure. When diffuse hyperplasia develops into a nodular type, the cells grow monoclonally and proliferate aggressively, with abnormal suppression of parathyroid hormone (PTH) secretion under high extracellular calcium. Based on histopathological and pathophysiological findings, patients with nodular hyperplasia in renal hyperparathyroidism might be refractory to medical treatment, including calcitriol pulse therapy. Thus, parathyroid surgery is indicated for individuals developing hypercalcemia, elevated PTH levels, and/or bone disease, who cannot be effectively treated medically. The detection of enlarged parathyroid glands by image diagnosis is another criterion for surgery. In our experience, parathyroidectomy is an effective treatment; however, the timing of the operation is important, because skeletal deformity and vessel calcification cannot be expected to diminish even after successful surgery. Technically, it is important to identify all parathyroid glands and, in autotransplantation, to use an adequate amount of suitable tissue, namely, a diffuse type of hyperplastic tissue, to guarantee satisfactory postoperative function.

Insulin resistance and arteriosclerosis obliterans in patients with NIDDM

OBJECTIVE

To investigate the risk factors for arteriosclerosis obliterans (ASO) in NIDDM, we measured insulin sensitivity and other risk factors including lipoprotein(a) [Lp(a)] in NIDDM patients with and without ASO.

RESEARCH DESIGN AND METHODS

A case-control study in 100 patients with NIDDM, 35 with and 65 without ASO, was performed. Insulin sensitivity was assessed by the short insulin tolerance test's K index (KITT). Duration of diabetes, a history of smoking, prevalence of hypertension, prevalence of coronary artery disease (CAD), serum C-peptide, 24-h urinary C-peptide, serum lipids, and Lp(a) were compared in the two groups.

RESULTS

Age, BMI, HbA1c, and fasting plasma glucose were comparable in the two groups. Patients with ASO were significantly more insulin resistant than patients without ASO (KITT 2.16 +/- 0.16 vs. 3.00 +/- 0.13%/min, P < 0.0001, respectively), had a longer duration of diabetes (10.3 +/- 1.2 vs. 7.5 +/- 0.8 years, P < 0.05), included a greater number of smokers (68.6 vs. 40.0%, P < 0.01), had a higher prevalence of CAD (60.0 vs. 16.9%, P < 0.01), and had a greater percentage of insulin therapy (48.6 vs. 29.2%, P < 0.05). However, urinary and serum C-peptide levels, serum lipids, and Lp(a) levels were comparable in the two groups. Multiple logistic regression analysis indicated that a history of smoking (odds ratio 3.70, P = 0.011), insulin resistance (odds ratio 3.68, P < 0.001), and an elevated Lp(a) level (odds ratio 1.03, P = 0.020) were independently related to ASO. When patients with CAD were removed from the logistic regression analysis, insulin resistance was most strongly related to ASO (odds ratio 20.9, P < 0.001).

CONCLUSIONS

Patients with ASO were characterized by a higher prevalence of CAD, a greater percentage of smokers, a greater percentage of insulin therapy, and a higher insulin resistance than were patients without ASO. Insulin resistance, especially, may be the most powerfully related to ASO. Lp(a) may play a minor role in the development of ASO.

Bacterial pneumonia causes augmented expression of the secretory leukoprotease inhibitor gene in the murine lung

The cDNA of murine secretory leukoprotease inhibitor (SLPI) was cloned from a mouse lung cDNA library. The amino acid sequence deduced from the cDNA showed 58 and 51% homology with those of human and porcine SLPI, respectively. A two-domain structure with similar amino acid sequences, four intradomain disulfide bonds, and high proline content, which are characteristics common to human and porcine SLPI, was also found in the mouse protein. The amino acid residues for the signal sequence and active site are also conserved in mouse SLPI. RNase protection assay showed the expression of the SLPI gene in liver, intestine, spleen, and epididymis, suggesting the distribution of SLPI in tissues other than lung and seminal vesicles. In the lung infected with Streptococcus pneumoniae strain FP1284, 10 h after inoculation of bacteria the number of SLPI mRNA transcripts was three times higher than baseline. The increased level of expression remained constant for at least 48 h. This result clearly contrasts to that obtained for spleen, in which the SLPI mRNA transcript level was mostly unchanged during the course of pneumonia. These facts suggested the local regulation of the SLPI gene expression in vivo in response to inflammatory stimuli at the site of inflammation.

Glucose tolerance, insulin secretion, and insulin sensitivity in nonobese and obese Japanese subjects

OBJECTIVE

To investigate the relative contributions of insulin secretion and insulin resistance to the development of glucose intolerance in Japanese subjects.

RESEARCH DESIGN AND METHODS

A cross-sectional study of 756 Japanese subjects (530 nonobese, 226 obese) was performed. A 75-g oral glucose tolerance test (OGTT) was given, and subjects were classified according to the World Health Organization (WHO) criteria (normal glucose tolerance [NGT], impaired glucose tolerance [IGT], and diabetes). Early-phase insulin secretion was assessed by the insulinogenic index (the ratio of the increment of insulin to that of plasma glucose [PG] 30 min after a glucose load [delta IRI0-30 min/delta PG0-30 min]). Total insulin secretion was assessed by mean immunoreactive insulin (IRI) during the OGTT, and insulin resistance was assessed by use of the homeostasis model [HOMA(R)].

RESULTS

Early-phase insulin secretion was significantly decreased in IGT, compared with patients with NGT, in both the nonobese and obese subjects (0.70 +/- 0.05 vs. 0.37 +/- 0.03, P < 0.01 and 1.36 +/- 0.19 vs. 0.73 +/- 0.08, P < 0.01, respectively). However, mean IRI and HOMA(R) in both nonobese and obese subjects with IGT and NGT were not statistically different. Subjects with diabetes showed a significant decline in early-phase and total insulin secretion and a significantly higher level of insulin resistance than did subjects with IGT. When the fasting glucose (FPG) exceeded 100 mg/dl, early-phase insulin decreased progressively. The graphed relationship between FPG and mean IRI did not show an inverted U-shape, and mean IRI decreased progressively when FPG exceeded 100-130 mg/dl. The pattern of changes in insulin secretion and insulin resistance associated with the progression of glucose intolerance was similar in both the nonobese and obese subjects.

CONCLUSIONS

The worsening from NGT to IGT in Japanese subjects may be associated with a decrease in early-phase insulin secretion in nonobese as well as in obese subjects. Hyperinsulinemia in IGT is not common. We suggest that impaired early-phase insulin secretion may be the initial abnormality in the development of glucose intolerance in Japanese people. Insulin resistance may be a consequence of hyperglycemia and/or obesity.

CD8 cytotoxic T-cell clone rapidly transfers autoimmune diabetes in very young NOD and MHC class I-compatible scid mice

A CD8 T-cell clone (YNK1.3) generated from acutely diabetic NOD mouse islets, showed proliferation and cytotoxicity when challenged with NOD and BALB/c islet cells and NOD-derived insulinoma cells. When 1-2 x 10(7) YNK1.3 cells were administered to 7-10-day-old NOD mice, the cells transferred overt diabetes very rapidly in each of the 16 recipients within 4 days of cell transfer. However, of 14 recipients receiving YNK 1.3 cells above 14 days of age none became diabetic. Fluorescent dye-labelled YNK1.3 cells extensively accumulated in the islets by 36 h after transfer in 7-day-old NOD recipients, while no significant insulitis was seen in 21-day-old recipients. Over half of NOD-scid recipients (5/9) rapidly became diabetic within 5 days after transfer of 1-2 x 10(7) YNK1.3 cells at 7 days of age, whereas only one of 12 recipients over 14 days of age became diabetic. Furthermore, YNK1.3 cells also transferred diabetes to H-2Kd-matched very young BALB/c-scid and CB17-scid mice, but not to C57BL/6-scid mice. Thus, optimally activated islet-specific CD8 T-cell clones are able to rapidly transfer diabetes to NOD and MHC class I compatible scid mice when a large enough number is administered at 7 days of age. Administration of monoclonal antibodies against adhesion molecules involved in the trafficking of lymphocytes from the circulation into the inflammatory tissues, could not prevent the cellular infiltration of YNK1.3 cells into the islets in 7-day-old NOD recipients. The results indicate that islet cells in the mouse around 7 days of age are generally susceptible to cytotoxic CD8 T cells, suggesting, therefore, that CD8 T cells may play an important role in the initiation of autoimmune diabetes in NOD mice.

A large right coronary artery-left ventricle fistula with mild volume overload on the left ventricle owing to its capacitive action--pulsed Doppler and cineangiographic analyses in a patient

A 54-year-old woman was admitted to our hospital because of a heart murmur without subjective symptoms. Angiography disclosed an enlarged right coronary artery and flow drainage into the left ventricle, ie, a large right coronary artery-left ventricle fistula. Analysis of pulsed Doppler studies and cineangiograms indicated considerable capacitance of this fistula owing to Windkessel action, which attenuated volume overload on the left ventricle. The features in this case suggest that evaluation of fistula hemodynamics is important in determining the overload on the ventricle through the fistula.

Expression of IFN-inducible protein-10 in chronic hepatitis

Chemokines such as IFN-inducible protein-10 (IP-10) and JE/monocyte chemotactic protein-1 (MCP-1) are induced in the murine liver in a tissue-specific manner. We examined whether IP-10 and MCP-1 are pathologically involved in chronic hepatitis. Whereas the serum levels of IP-10 and MCP-1 in patients with chronic persistent hepatitis C were elevated compared with those in normal volunteers, both chemokine levels were further significantly higher in patients with the active form (chronic active hepatitis (CAH)). The elevated IP-10 level was not a general phenomenon of inflammation, because it was not seen in patients with rheumatoid arthritis, whereas MCP-1 levels were elevated to the same extent in both patient groups. Better responsiveness to IFN therapy in CAH was related to lesser grades of necroinflammatory activity and was predicted by the lower IP-10 and higher MCP-1 levels. IP-10 levels in patients cured by IFN therapy decreased to the levels in normal volunteers, while the MCP-1 levels only slightly decreased. Serum levels of both chemokines in patients who were not cured remained unchanged after IFN therapy. In situ hybridization analysis of CAH revealed that IP-10 mRNA was expressed mainly in hepatocytes around intralobular focal and periportal piecemeal necrosis, while some MCP-1 mRNA was expressed in some sinusoidal cells. These results suggested that IP-10 plays a specific role in the intralobular accumulation of mononuclear cells and/or the death of hepatocytes in chronic hepatitis.

Expression of IFN-inducible protein-10 in chronic hepatitis

Chemokines such as IFN-inducible protein-10 (IP-10) and JE/monocyte chemotactic protein-1 (MCP-1) are induced in the murine liver in a tissue-specific manner. We examined whether IP-10 and MCP-1 are pathologically involved in chronic hepatitis. Whereas the serum levels of IP-10 and MCP-1 in patients with chronic persistent hepatitis C were elevated compared with those in normal volunteers, both chemokine levels were further significantly higher in patients with the active form (chronic active hepatitis (CAH)). The elevated IP-10 level was not a general phenomenon of inflammation, because it was not seen in patients with rheumatoid arthritis, whereas MCP-1 levels were elevated to the same extent in both patient groups. Better responsiveness to IFN therapy in CAH was related to lesser grades of necroinflammatory activity and was predicted by the lower IP-10 and higher MCP-1 levels. IP-10 levels in patients cured by IFN therapy decreased to the levels in normal volunteers, while the MCP-1 levels only slightly decreased. Serum levels of both chemokines in patients who were not cured remained unchanged after IFN therapy. In situ hybridization analysis of CAH revealed that IP-10 mRNA was expressed mainly in hepatocytes around intralobular focal and periportal piecemeal necrosis, while some MCP-1 mRNA was expressed in some sinusoidal cells. These results suggested that IP-10 plays a specific role in the intralobular accumulation of mononuclear cells and/or the death of hepatocytes in chronic hepatitis.

Telomerase elevation in pancreatic ductal carcinoma compared to nonmalignant pathological states

Telomerase activity was measured in surgically resected tissues of 20 human pancreatic ductal carcinomas, 12 adenomas, 5 pancreatitis tissues, 14 normal pancreatic ducts, and 13 normal pancreatic tissues (primarily made up of acinar cells) using a PCR-based telomerase assay. Relative telomerase activity was expressed as the equivalent telomerase intensity of the number of cells of a human pancreatic cancer cell line, MIA PaCa-2, per microgram of protein in the tissue samples. The median value (25th percentile, 75th percentile) of relative telomerase activity in pancreatic carcinomas was 13.2 (3.58, 244), which was significantly higher relative to normal tissues, normal ducts, pancreatitis tissues, and adenomas (P < 0.0001). When the cutoff value of relative telomerase activity was set at 1.00 and 3.00, the positivity rates of telomerase activity in pancreatic ductal carcinomas were 100 and 80%, respectively. Some of the adenoma samples displayed a weak telomerase ladder. However, when semiquantitatively analyzed, the relative telomerase activity of all adenoma tissues was less than 1.00 equivalent cells per microgram protein of the tissues, which was equivalent to the values encountered in normal ducts. Thus, our results indicate that reactivation of telomerase may occur at a late stage of pancreatic ductal carcinogenesis. Therefore, telomerase may be a specific marker for distinguishing pancreatic cancer from pancreatitis and adenomas.

Histopathology, pathophysiology, and indications for surgical treatment of renal hyperparathyroidism

Morphological changes in the parathyroid glands evidently occur early during renal failure. Histopathological investigations have suggested that parathyroid cells initially increase diffusely with a normal lobular structure (diffuse hyperplasia). The parathyroid glands then become hyperplastic with some nodules (nodular hyperplasia). Cells in nodules grow monoclonally and proliferate aggressively, possibly induced by some kind of genetic abnormality. Pathophysiologically, in cells consisting of hyperplastic nodules, suppression of parathyroid hormone (PTH) secretion under the influence of excess extracellular calcium is more deranged, possibly due to a reduction of calcium-sensing receptors. Vitamin D receptor density decreases more severely in these cells, possibly causing abnormal PTH synthesis, PTH secretion, and even parathyroid cell proliferation. According to histopathological and pathophysiological findings, patients with nodular hyperplasia during renal hyperparathyroidism may be refractory to medical treatments, including calcitriol pulse therapy, and parathyroidectomy will become necessary. There is a relationship between the pattern of parathyroid hyperplasia and glandular weight in which glands weighing more than 500 mg may be pathognomonic of nodular hyperplasia. Glandular volume, estimated by ultrasonography, is one of several important criteria indicating parathyroidectomy. In order to prevent a recurrence of hyperparathyroidism, all nodular hyperplastic tissue should be extirpated.

Alkylation-induced apoptosis of embryonic stem cells in which the gene for DNA-repair, methyltransferase, had been disrupted by gene targeting

An enzyme O6-methylguanine-DNA methyltransferase (MGMT) catalyzes transfer of a methyl group from O6-methylguanine and O4-methylthymine of alkylated DNA to its own molecule, thereby repairing the pre-mutagenic lesions in a single step reaction. Making use of gene targeting, we developed mouse embryonic stem (ES) cell lines deficient in the methyltransferase. Quantitative immunoblot analysis and enzyme assay revealed that MGMT-/- cells, in which both alleles were disrupted, contained no methyltransferase protein while cells with one intact allele (MGMT+/-) contained about half the amount of protein carried by the parental MGMT+/+ cells. MGMT-/- cells have an extremely high degree of sensitivity to simple alkylating agents, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and N-methyl-N-nitrosourea (MNU), whereas MGMT+/- cells are slightly more sensitive to these agents, as compared with findings from normal cells. A high frequency of mutation was induced in MGMT-/- cells on exposure to a relatively low dose of MNNG. Electrophoretic analyses of the DNAs as well as fluorochrome staining of the cells revealed that MGMT-/- cells treated with MNNG undergo apoptotic death, which occurs after G2-M arrest in the second cycle of cell proliferation.

Use of serum creatine kinase MM isoforms for predicting the progression of left ventricular dilation in patients with hypertrophic cardiomyopathy

Serum creatine kinase (CK) isoforms were examined to detect the progression of left ventricular (LV) enlargement with reduced motion, resembling dilated cardiomyopathy (DCM), in hypertrophic cardiomyopathy (HCM). Changes in LV indices were determined annually by echocardiography in 51 patients until serum measurements (first follow-up period, 6.5 +/- 2.2 years). Serum creatine isoforms (CKMM1, CKMM2 and CKMM3) were measured with high-voltage electrophoresis in 35 of these patients from 1991 to 1992, and the data for these latter patients are reported here. Serum total CK, CKMB, lactate dehydrogenase and its isoenzyme LDH1 were also measured. The changes in LV indices were further monitored until January, 1995 (second follow-up). During the 2 follow-up periods, the patients in the on-going group showed a reduction in the LV ejection fraction (LVEF) to < 55% with LV end-diastolic dimension (LVDd) < 55 mm, and those in the DCM-like group showed a reduction in LVEF to < 55% and an increase in LVDd to > 55 mm. During the first follow-up period, LVEF and LVDd remained at > or = 55% and < 55 mm, respectively, in 26 patients (nonprogressive-disease group), while 3 patients entered the on-going group and 6 entered the DCM-like group. The CKMM3/CKMM1 ratios in the on-going and DCM-like groups were significantly higher than those in the control and nonprogressive-disease groups. The CKMM3/CKMM1 ratio was significantly correlated with the annual rate of change for the LV end-systolic dimension (LVDs), LVDd, and LVEF, with the closest correlation observed for the annual change in LVDs. Moreover, 5 patients in the nonprogressive-disease group with elevation of the CKMM3/CKMM1 ratio to > + 2SD above the mean for the controls had an elevated annual change in LVDs within +/- 1SD of the mean in the DCM-like group. These results indicate that the ratio of CKMM3 to CKMM1 can be used to predict the progression of LV enlargement in HCM.

Renal transplantation and secondary hyperparathyroidism

Secondary hyperparathyroidism (2'HPT) improves after renal transplantation (RTx) along with recovered function of the renal allograft. However, normal renal function does not last long due to rejection, drug-induced nephrotoxic nepthropathy, or recurrence of post-transplant glomerulonephritis. Therefore, improved calcium and phosphate metabolism, and parathyroid function after RTx fluctuate in accordance with the function of the renal allograft. In cases with severe 2'HPT, parathyroidectomy should be performed before RTx because hypercalcemia due to secondary or tertiary hyperparathyroidism aggravates the renal allograft function. In the follow-up of mild 2'HPT after RTx, hypercalcemia and vascular calcification should be monitored carefully by serum parathyroid hormone, calcium and phosphate concentrations, alkaline phosphatase activity, and bone X-ray film. If serum calcium level exceeds 12 mg/dl, parathyroidectomy (PTx) should be performed to prevent the acceleration of vascular calcification. Total PTx with forearm allograft is a preferred surgical procedure for 2'HPT even after RTx.

Surgical treatment of renal hyperparathyroidism

Advanced secondary (renal) hyperparathyroidism induced by chronic renal disturbance is one of the most serious complications for long-term hemodialysis patients. Parathyroidectomy is indicated in patients with severely advanced renal hyperparathyroidism refractory to medical treatment (including calcitriol pulse therapy) and the clinical effect of parathyroidectomy is striking. However, skeletal deformity, vessel calcification, and remarkable reduction of bone content is irreversible, and it is important to perform parathyroidectomy at right time. Based on histopathological and pathophysiological investigations, nodular hyperplasia is monoclonal neoplasia with abnormal parathyroid hormone (PTH) response to extracellular calcium and vitamin D. When parathyroid hyperplasia progresses to nodular hyperplasia, parathyroidectomy should be required. Total parathyroidectomy with forearm autograft is the preferable procedure for renal hyperparathyroidism, especially for patients who need to continue hemodialysis treatment after parathyroidectomy. Removal of all parathyroid glands, including supernumerary glands, at the initial operation, and proper choice of adequate parathyroid tissue for autograft, are important to prevent persistent and recurrent hyperparathyroidism. Preoperative image diagnosis is useful for localization, and routine resection of thymic tissue is necessary to remove supernumerary glands. In our series of 548 patients, graft-dependent recurrent hyperparathyroidism was not negligible and the incidence was about 20% at the 5th year postoperatively. Enlarged autografts of parathyroid tissue could be removed from forearm under local anesthesia with fewer invasions. The function of autografted parathyroid tissue is nearly satisfactory and no re-transplantation of cryopreserved parathyroid tissue was necessary. To avoid adynamic bone disease, relatively high PTH level is required-over-suppression of PTH by excess of vitamin D and calcium salts should be avoided. In our experience, total parathyroidectomy with forearm autograft is very effective and adequate treatment for advanced renal hyperparathyroidism, and parathyroid function can be controlled after parathyroidectomy.

Parathyroid function and bone metabolic markers in primary and secondary hyperparathyroidism

Remarkable changes of parathyroid function immediately after parathyroidectomy were evaluated in primary (PHPT) and secondary (RHPT) hyperparathyroidism. Bone metabolism was also evaluated by new specific markers of bone formation and resorption. A rapid decline into the undetectable range, and a rapid recovery of serum bioactive parathyroid hormone (PTH) concentrations were observed after parathyroidectomy in PHPT. Since the function of the remnant parathyroid glands was not clear, we investigated the transcription of PTH mRNA. Despite the suppression of PTH secretion in the remnant parathyroid glands, no significant difference was found in the amount of PTH mRNA present in an adenoma as compared to a remnant gland when evaluated by cytoplasmic dot hybridization and in situ hybridization. Although measurement of serum PTH concentration by assays of inactive fragment was available for the longterm follow-up of PTH function in RHPT, parathyroid function should be evaluated by biologically active intact PTH immediately after operation. The PTH gradient also was successfully evaluated by the measurement of intact PTH. A discrepancy was observed between bone resorption evaluated by type I collagen cross-linked N-telopeptide as compared to bone formation evaluated by osteocalcin immediately after operation. This discrepancy will improve and bone mineral density will increase in the first 6 months after parathyroidectomy.

Surgery for renal hyperparathyroidism--experience of 640 cases

Our experience in the field of surgery for renal hyperparathyroidism, gained from 640 cases, the largest number in the world, was reviewed. Additional comments were made on the relation between renal transplantation and renal hyperparathyroidism.

Histopathology, pathophysiology, and indications for surgical treatment of renal hyperparathyroidism

Morphological changes in the parathyroid glands evidently occur early during renal failure. Histopathological investigations have suggested that parathyroid cells initially increase diffusely with a normal lobular structure (diffuse hyperplasia). The parathyroid glands then become hyperplastic with some nodules (nodular hyperplasia). Cells in nodules grow monoclonally and proliferate aggressively, possibly induced by some kind of genetic abnormality. Pathophysiologically, in cells consisting of hyperplastic nodules, suppression of parathyroid hormone (PTH) secretion under the influence of excess extracellular calcium is more deranged, possibly due to a reduction of calcium-sensing receptors. Vitamin D receptor density decreases more severely in these cells, possibly causing abnormal PTH synthesis, PTH secretion, and even parathyroid cell proliferation. According to histopathological and pathophysiological findings, patients with nodular hyperplasia during renal hyperparathyroidism may be refractory to medical treatments, including calcitriol pulse therapy, and parathyroidectomy will become necessary. There is a relationship between the pattern of parathyroid hyperplasia and glandular weight in which glands weighing more than 500 mg may be pathognomonic of nodular hyperplasia. Glandular volume, estimated by ultrasonography, is one of several important criteria indicating parathyroidectomy. In order to prevent a recurrence of hyperparathyroidism, all nodular hyperplastic tissue should be extirpated.

Surgical treatment of renal hyperparathyroidism

Advanced secondary (renal) hyperparathyroidism induced by chronic renal disturbance is one of the most serious complications for long-term hemodialysis patients. Parathyroidectomy is indicated in patients with severely advanced renal hyperparathyroidism refractory to medical treatment (including calcitriol pulse therapy) and the clinical effect of parathyroidectomy is striking. However, skeletal deformity, vessel calcification, and remarkable reduction of bone content is irreversible, and it is important to perform parathyroidectomy at right time. Based on histopathological and pathophysiological investigations, nodular hyperplasia is monoclonal neoplasia with abnormal parathyroid hormone (PTH) response to extracellular calcium and vitamin D. When parathyroid hyperplasia progresses to nodular hyperplasia, parathyroidectomy should be required. Total parathyroidectomy with forearm autograft is the preferable procedure for renal hyperparathyroidism, especially for patients who need to continue hemodialysis treatment after parathyroidectomy. Removal of all parathyroid glands, including supernumerary glands, at the initial operation, and proper choice of adequate parathyroid tissue for autograft, are important to prevent persistent and recurrent hyperparathyroidism. Preoperative image diagnosis is useful for localization, and routine resection of thymic tissue is necessary to remove supernumerary glands. In our series of 548 patients, graft-dependent recurrent hyperparathyroidism was not negligible and the incidence was about 20% at the 5th year postoperatively. Enlarged autografts of parathyroid tissue could be removed from forearm under local anesthesia with fewer invasions. The function of autografted parathyroid tissue is nearly satisfactory and no re-transplantation of cryopreserved parathyroid tissue was necessary. To avoid adynamic bone disease, relatively high PTH level is required-over-suppression of PTH by excess of vitamin D and calcium salts should be avoided. In our experience, total parathyroidectomy with forearm autograft is very effective and adequate treatment for advanced renal hyperparathyroidism, and parathyroid function can be controlled after parathyroidectomy.

Possible participation of cyclooxygenase-2 in the recurrence of allergic inflammation in rats

In the recurrence of allergic inflammation in a rat air pouch model, pouch fluid volume, prostaglandin E2 concentration in the pouch fluid, leukocyte infiltration into the pouch fluid, and granulation tissue weight were markedly increased by the antigen challenge. To clarify the role of cyclooxygenase-2 in the recurrence of allergic inflammation, the time-course of changes in protein levels of cyclooxygenase-1 and cyclooxygenase-2 in the granulation tissue and in the infiltrated leukocytes was examined by Western blot analysis. It was shown that cyclooxygenase-1 levels in the granulation tissue and in the infiltrated leukocytes were not changed by the antigen challenge, but cyclooxygenase-2 levels were increased. Furthermore, treatment with the selective cyclooxygenase-2 inhibitor, NS-398 ([N-2(cyclohexyloxy-4-nitrophenyl]-methanesulfonamide), suppressed the recurrence of allergic inflammation as did the non-selective cyclooxygenase-1/cyclooxygenase-2 inhibitor, indomethacin. The steroidal anti-inflammatory drug, dexamethasone, inhibited the induction of cyclooxygenase-2, and suppressed the allergic inflammation. These findings strongly suggested that cyclooxygenase-2 induced by the antigen challenge plays a role in the recurrence of inflammation induced by the allergic mechanism.

Organization and expression of the mouse MTH1 gene for preventing transversion mutation

An enzyme, 8-oxo-7,8-dihydrodeoxyguanosine triphosphatase (8-oxo-dGTPase), is present in various organisms and plays an important role in the control of spontaneous mutagenesis. The enzyme hydrolyzes 8-oxo-dGTP, an oxidized form of dGTP, to 8-oxo-dGMP, thereby preventing the occurrence of A:T to C:G transversion, caused by misincorporation. We isolated the mouse genomic sequence encoding the enzyme and elucidated its structure. The gene, named MTH1 for mutT homologue 1, is composed of at least five exons and spans approximately 9 kilobase pairs. A genomic region containing the pseudogene was also isolated. The promoter region for the gene is GC-rich, contains many AP-1 and AP-2 recognition sequences, and lacks a typical TATA box. Primer extension and S1 mapping analyses revealed the existence of multiple transcription initiation sites, among which a major site was defined as +1. The putative promoter region was placed upstream of the chloramphenicol acetyltransferase reporter gene, and control of expression of the gene was examined by introducing the construct into mouse NIH 3T3 cells. Deletion analysis indicated that a sequence from -321 to +9 carries the basic promoter activity while an adjacent region, spanning from +352 to +525 stimulates the frequency of transcription.

A unique enzyme from Saccharothrix sp. catalyzing D-amino acid transfer

A newly isolated actinomycete belonging to Saccharothrix sp. was found to produce a unique enzyme catalyzing D-amino acid transfer. The enzyme, which was tentatively named D-amino acid transferase, was purified 2600-fold to electrophoretic homogeneity and the molecular mass was 41 kDa. The enzyme was D-configuration specific and recognized aromatic D-amino acid esters to form oligo D-amino acid esters. D-Phenylalanine ester was favored as substrate over other D-amino acid esters. The optimum conditions for oligo D-phenylalanine ester formation by D-amino acid transferase were pH 7.0 and 40 degrees C. The enzyme was inhibited by DAN, EPNP and DFP.

Semi-quantitative analysis of telomerase in pancreatic ductal adenocarcinoma

Using a polymerase chain reaction-based amplification assay, we measured telomerase activity in surgically resected pancreatic ductal carcinomas (n = 16 cases) and normal ducts (n = 6), comparing findings with the telomerase activity of a human pancreatic cancer cell line, MIA PaCa-2, as a standard, i.e., relative telomerase activity was determined. Telomerase activity was expressed as the equivalent telomerase intensity of the number of cells of MIA PaCa-2 per microgram protein of tissue samples. The median value for telomerase activity in normal pancreatic ducts was 0.13 and the 25th and 75th percentile were 0.01 and 0.76. The median value for telomerase activity in pancreatic ductal adenocarcinoma was 34.7 (25th percentile, 4.98; and 75th percentile, 296), significantly higher than that of normal ducts (P < 0.001). When the cut-off value was set at 1.0 and 3.0, the telomerase positivity rate of pancreatic ductal adenocarcinomas was 100% and 81.3%, respectively. Telomerase may be specific marker for pancreatic ductal carcinomas.