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Y Shimada
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Temperature-dependent cardioprotection of exogenous substrates in long-term heart preservation with continuous perfusion: twenty-four-hour preservation of isolated rat heart with St. Thomas' Hospital solution containing glucose, insulin, and aspartate.
BACKGROUND AND METHODS: Using an isolated working rat heart model, we determined the effects of glucose, insulin, and aspartate on recovery of cardiac function when used as components of preservation solution at different temperatures. After measurement of baseline cardiac function, hearts (n = 6 per group) were perfused with oxygenated St. Thomas' Hospital solution containing (1) vehicle, glucose (9 mmol/L) or aspartate (20 mmol/L) for 12 hours at either 20 degrees or 4 degrees C; (2) glucose or glucose + insulin (10 U/L) at 20 degrees C for 20 hours; and (3) glucose + insulin at 20 degrees C or glucose + insulin + aspartate at either 20 degrees or 4 degrees C for 24 hours. Cardiac function was measured after preservation and expressed as a percentage of baseline values. RESULTS: At 20 degrees C, both glucose and aspartate increased recovery of cardiac output (vehicle, 57.7% +/- 3.8%; glucose, 76.5% +/- 2.4% [p < 0.05 versus vehicle]; aspartate, 79.9% +/- 1.4% [p < 0.05 versus vehicle]). At 4 degrees C, glucose decreased recovery of cardiac output, whereas aspartate did not change the value (vehicle, 74.4% +/- 2.2%; glucose, 61.4% +/- 2.8% [p < 0.05 versus vehicle]; aspartate, 80.5% +/- 1.7%). The addition of insulin to glucose increased recovery of cardiac output (glucose, 24.6% +/- 4.0%; insulin + glucose, 69.2% +/- 2.0%: p < 0.05). The combined use of these three agents showed an additive effect in improvement of recovery of cardiac output at 20 degrees C (glucose + insulin, 64.2% +/- 2.2%; glucose + insulin + aspartate, 76.0% +/- 1.1%; p < 0.05), but the recovery at 4 degrees C (63.1% +/- 1.8%) was significantly lower than at 20 degrees C. CONCLUSIONS: These results suggest that glucose and aspartate afford differential cardioprotective effects depending on the temperature of the preservation solution and that combined use of glucose, insulin, and aspartate at the optimal temperature may extend graft preservation time.
[Care of esophageal cancer patients with diabetes mellitus--preoperative management and treatment].
The care of esophageal cancer patients with diabetes mellitus is described. The main points are as follows. 1. Prevention and control of infection. 2. Sufficient nutritional support (2000 Kcal/day) and hydration. 3. Control of plasma glucose level (150 mg/dl-250 mg/dl) by means of insulin. 4. An absence of ketone bodies and minimum glucose level (< 10 g/day) in the urine. 5. Prevention and control of hypoglycemia. Good control of diabetes mellitus in esophageal cancer patients may contribute to reduced surgical rislcs.
Prostaglandin E1 ameliorates decreased tracheal blood flow after esophagectomy and aggressive upper mediastinal lymphadenectomy for esophageal carcinoma.
BACKGROUND: Aggressive upper mediastinal lymphadenectomy contributes to a better survival rate after esophageal resection to treat esophageal carcinoma, but it also increases postoperative respiratory complications. Devascularization of the airways because of mediastinal dissection is considered to be a cause of respiratory dysfunction. The present study attempts to clarify whether or not tracheal blood flow (TBF) deteriorates after esophagectomy and, if so, whether or not intravenous prostaglandin E1 (PGE1) attenuates the deterioration. STUDY DESIGN: Patients undergoing esophagectomy and aggressive upper mediastinal lymphadenectomy for the treatment of esophageal carcinoma (EC group, n = 12) or abdominal surgery (control group, n = 6) were enrolled in this study. Measurement of TBF was performed using a laser Doppler flowmeter. Changes in TBF induced by surgery and postoperative intravenous PGE1 were studied in both groups. RESULTS: The TBF deteriorated significantly in the EC group (21.78 +/- 9.60 to 11.24 +/- 4.45 mL/minute/10(-1) kg, p = 0.002) but did not change in the control group (26.13 +/- 6.84 to 26.61 +/- 4.69 mL/minute/10(-1) kg, p = 0.7371). Postoperative intravenous PGE1 partially, but significantly, reversed the deterioration in TBF in the EC group (11.53 +/- 4.58 to 14.87 +/- 6.30 mL/minute/10(-1) kg, p = 0.0207) but did not effect the control group (29.41 +/- 7.89 to 29.41 +/- 8.79 mL/minute/10(-1) kg, p = 0.9989). CONCLUSIONS: Esophagectomy and aggressive upper mediastinal lymphadenectomy cause a deterioration in TBF that is partially attenuated by PGE1.
[A case of severe hypertension caused by stellate ganglion block in a patient with facial palsy].
We report a case of severe hypertension following stellate ganglion block. A 61-year old woman received the left stellate ganglion block with 5 ml of 1% mepivacaine for her left facial palsy. Before the stellate ganglion block, blood pressure was 120/68 mmHg and heart rate was 62 b.p.m. Seven minutes after the left stellate ganglion block, blood pressure increased to 230/140 mmHg, but heart rate was unchanged. Systolic blood pressure remained above 190 mmHg for 60 minutes following the stellate ganglion block. We suggest that the extreme increase in blood pressure was due to the vagal nerve block associated with the left stellate ganglion block.
[The effect of continuous perfusion with St. Thomas' Hospital cardioplegic solution containing glucose, insulin and L-aspartate on functional recovery after myocardial preservation in the rat].
UNLABELLED: The aim of this study was to determine the effect of the continuous perfusion with St. Thomas' Hospital cardioplegic solution (ST solution) containing glucose, insulin and L-aspartate upon post-preservation recovery of cardiac function in the isolated rat heart. METHODS: Hearts from Wistar male rats were perfused with Krebs-Henseleit bicarbonate buffer (KHBB) solution and cardiac function was measured using an isolated working heart preparation. Hearts were then preserved by continuous perfusion, (1) with ST solution or ST solution containing L-aspartate (20 mmol/L9 at 20 degrees C and 4 degrees C for 12 hours, (2) with ST solution containing L-aspartate at 4 degrees C for 24 hours, (3) with ST solution containing glucose (9 mmol/L) and insulin (10 U/L solution) or ST solution containing glucose, insulin and L-aspartate at 20 degrees C for 24 hours. This was followed by 15 minutes of Langendorff perfusion and 20 minutes of working perfusion with KHBB solution. During the working perfusion in the post-preservation period, cardiac function was remeasured. RESULTS: (1) At 20 degrees C, percent recovery of cardiac output (%CO) was 57.7 +/- 3.8% and 79.9 +/- 1.4*% in the L-aspartate-free group and the L-aspartate-containing group, respectively (*p < 0.05). At 4 degrees C, %CO was 74.4 +/- 2.2% and 80.5 +/- 1.7% in the L-aspartate-free group and the L-aspartate-containing group, respectively (NS). (2) %CO in L-aspartate-containing group at 4 degrees C decreased to 46.8 +/- 2.4% when preservation time was extended to 24-hours from 12 hours. (3) On the other hands, the addition of L-aspartate to the ST solution containing glucose and insulin resulted in an additive protection and %CO was 76.0 +/- 1.1% even after 24 hour preservation at 20 degrees C. CONCLUSIONS: Our results indicate that L-aspartate as an additive to perfusion medium might be beneficial for myocardial preservation, and that at 20 degrees C, the addition of L-aspartate to the ST solution containing glucose and insulin could improve the post-preservation recovery after the 24-hour preservation.
Development of connectin/titin and nebulin in striated muscles of chicken.
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Construction of a divalent cell adhesive lysozyme by introducing the Arg-Gly-Asp sequence at two sites.
To increase the cell adhesion activity of 74RGD4, an RGDS-inserted mutant between Val74 and Asn75 of human lysozyme, one more site for the RGD introduction was investigated in the lysozyme molecule. We found that 47RGD4 with RGDS in place of AGDR (residues 47 to 50) in a beta-turn region possesses the same level of adhesion activity as that of 74RGD4. The acceptance of the RGD introduction in the beta-turn region of human lysozyme is in good agreement with recent studies on the functional conformation of RGD. We constructed (47,74)RGD4, a mutant containing RGD at two sites, by combining the N-terminal domain of 47RGD4 and the C-terminal domain of 74RGD4. The (47,74)RGD4 lysozyme, with two functional RGD sequences, exhibits even higher cell adhesion activity than that of 74RGD4 or 47RGD4.
Reduced fidelity of DNA synthesis in cell extracts from chemically induced primary thymic lymphomas of mice.
To examine whether the fidelity of DNA synthesis is reduced in tumor cells, M13 mp2-based fidelity assays were carried out using 15 samples of whole-cell extracts from primary mouse thymic lymphomas induced by alkylating agents. We found that DNA synthesis activities of thymic lymphomas, detected as incorporation of [3H]TTP into acid-insoluble materials, were 2- to 10-fold higher compared to those of normal thymus. Furthermore, mutant frequencies in the forward mutation assay of DNA synthesis were increased 2- to 7-fold in cell extracts from thymic lymphomas compared to those from normal thymus. As the DNA polymerase beta (pol beta) activity was extremely high in the thymic lymphomas, we screened mutations in the pol beta gene to examine the possibility of involvement of mutated pol beta in reduction of the fidelity of DNA synthesis. Of 20 lymphomas, one case of point mutation (T to A) was found by reverse transcription-PCR single-strand conformation polymorphism analysis. These results suggest that the mutagenic DNA synthesis is involved in murine thymic lymphoma genesis, although mutation of the pol beta gene is not a major causal event.
[A case of gastric cancer developed in the gastric tube 11 years after subtotal esophagectomy for esophageal cancer].
A case of adenocarcinoma developed in the reconstructed gastric tube after esophagectomy was reported. The patient was 66 years old man and he had received subtotal esophagectomy for the carcinoma of the esophagus 11 years previously. The follow-up examination of upper GI series revealed an ulcerative lesion in the lower part of the gastric tube and endoscopic biopsy showed adenocarcinoma. The partial resection of the lower gastric tube with mediansternotomy was performed because of limiting the invasion of the carcinoma. Pathological examination showed that poorly differentiated adenocarcinoma with signet ring cells had invaded muscularis propria. The postoperative course was uneventful and he is well without any recurrence 6 months after the operation. A double carcinoma, such as esophageal cancer concomitant gastric cancer is not rare, but a carcinoma of the gastric tube which was substituted for the esophagus is rare. Recently, the incidence of carcinoma of the gastric tube is increasing due to the increasingly long-term survival rate of patients who had esophageal carcinoma. In order to ensure the early detection of a second carcinoma which can minimalize damage from curative resections, follow up examinations should be conducted with the utmost diligence.
Relationship of the ipsilateral rotation in night period and striatal dopamine content reduction in unilateral nigrostriatal 6-OHDA lesioned rats.
In order to discriminate well-lesioned rats after unilateral microinjection of 6-OHDA into the nigrostriatal dopamine system, we measured the spontaneous rotation in the night period and calculated the rate of ipsilateral rotation movement. The rate of ipsilateral rotation movement increased along with the total rotation movement. The rats with over 95% of ipsilateral rotation kept the rate relatively constant for 4 weeks after 6-OHDA lesion and showed a significant increase of contralateral rotation (253.2 +/- 37.9) as compared with the rat that had lower than 95% ipsilateral rotation (3.6 +/- 1.4) after the injection of apomorphine (0.25 mg/kg, s.c.). The reduction percentages of striatal DA contents in animals with unilateral rotation over 95% and under 95% to the lesioned side were 97.8 +/- 0.6% and 59.6 +/- 5.8% (P < 0.001), respectively. The rats with over 90% reduction of striatal DA levels corresponded nicely to rats with 95% ipsilateral rotation among rats injected with apomorphine. These results suggested that the evaluation of ipsilateral rotation, taken the level of 95% rotation to the lesioned side as a standard, was able to discriminate well-lesioned rats without apomorphine treatment after unilateral nigrostriatal 6-OHDA application.
Cloning, sequencing and expression of a novel cDNA encoding human vacuolar ATPase (14-kDa subunit).
A cDNA encoding the 14-kDa subunit of vacuolar ATPase was cloned from human fetal brain. The sequence was composed of 680 nucleotides containing an open reading frame of 357 nucleotides. The deduced peptide sequence consisted of 119 amino acid residues with a calculated molecular weight of 13,369 Da and a pI of 5.19. Overall, this amino-acid sequence was respectively 69% and 70% identical to those of Manduca sexta and Drosophila melanogaster 14-kDa subunits, although the two representatives of Class Insecta were remarkably similar to one another (91% identity). Three regions in particular (the N-terminal, amino acids 5-36; the middle, residues 58-68; and the C-terminal, residues 88-118) were highly conserved. Hence, we think that the 14-kDa subunits have evolved from the same ancestral gene, and that the three conserved regions are important for the structure and function of vacuolar ATPase. A single 0.8-kb band was detected in various human tissues by Northern blot analysis. Since the human 14-kDa subunit is expressed ubiquitously, it might be a housekeeping protein. A separate transcript found in the cDNA library lacked a 6-bp segment in the 5' non-coding region (nucleotides -40 to -35) and also carried a 23C to T (8Thr to Ile) point mutation in the coding region; these minor differences likely reflected normal polymorphism.
The sequence of a rat cDNA encoding thrombopoietin.
Overlapping cDNA clones encoding rat thrombopoietin (TPO) were isolated from liver-derived cell line cDNA libraries and the nucleotide sequences were determined. The deduced 326-amino-acid rat TPO showed significant homology to the known TPO of other species, especially in the N-terminal sequence.
Congenital dumbbell neuroblastoma.
STUDY DESIGN: New babies with neurologic deficits resulting from intraspinal extension of congenital neuroblastoma is very unusual. Two patients with congenital dumbbell neuroblastoma with paraplegia are described, and 16 other cases are reviewed. OBJECTIVE: To study the clinical features and prognosis of congenital dumbbell neuroblastoma. SUMMARY OF BACKGROUND DATA: Only 16 cases were found in the literature. METHODS: Two girls were diagnosed and underwent surgery. RESULTS: Although no recurrence occurred in both patients, incomplete paresis remained. Corrective surgery was needed because of the post-laminectomy spinal deformity in patient 2. CONCLUSIONS: Although a high survival rate in patients with congenital dumbbell neuroblastoma is encouraging, the poor neurologic recovery is of great concern. The authors recommend an early diagnosis by magnetic resonance imaging and early spinal cord decompression followed by chemotherapy for congenital dumbbell neuroblastoma.
Reaction mechanism of T4 endonuclease V determined by analysis using modified oligonucleotide duplexes.
The reaction mechanism of bacteriophage T4 endonuclease V was investigated using modified oligodeoxyribonucleotide duplexes containing a cis-syn thymine dimer. For the pyrimidine dimer glycosylase step, the formation of a covalent intermediate has been proposed. A fluorine atom was attached to the 2'-position of the 5'-component of the thymine dimer site, which could stabilize the covalent complex and prevent the ring opening of the sugar moiety. The strand cleavage of the 12 base pair substrate analog did not occur, although the glycosyl bond was cleaved by this enzyme. A covalent enzyme--substrate complex was separated by gel electrophoresis under denaturing conditions. It was shown that the enzyme molecules were completely converted to a stable complex in the reaction mixture. Two mechanisms have been proposed for the beta-elimination step. A 12-mer containing a phosphorothioate linkage between adjacent thymidines was prepared. The diastereomers were separated, and the absolute configurations were determined. After formation of the thymine dimer and 32P-labeling of the 5'-terminus, these oligonucleotides were annealed to the complementary 12-mer, and the reaction rates of the pyrimidine dimer glycosylase step and the overall reaction for each duplex were measured under the substrate-saturation conditions. The rate constants indicated that the chemical reaction at the beta-elimination step was rate-limiting. Since no difference was observed in the rate constants for the Rp- and Sp-phosphorothioate substrates, it is concluded that the beta-elimination reaction is catalyzed, not by the internucleotide phosphate, but by an amino acid residue of the enzyme.
Structure of a conformationally constrained Arg-Gly-Asp sequence inserted into human lysozyme.
To examine the effect of a conformational constraint introduced into the Arg-Gly-Asp (RGD) sequence on cell adhesion activity, we constructed a mutant protein by inserting an RGD-containing sequence flanked by two Cys residues between Val74 and Asn75 of human lysozyme. The CRGDSC-inserted lysozyme was expressed in yeast, purified, and designated as Cys-RGD4. Using baby hamster kidney cells, Cys-RGD4 was shown to possess even higher cell adhesion activity than that of the RGDS-inserted lysozyme, RGD4. The Cys-RGD4 protein was co-crystallized with a lysozyme inhibitor, tri-N-acetylchitotriose, and the three-dimensional structure was determined at 1.6-A resolution by x-ray crystallography. In contrast to RGD4, the inserted RGD-containing region of Cys-RGD4 was well defined. The structural analysis revealed that the two inserted Cys residues form a new disulfide bond in Cys-RGD4, as expected, and that the RGD region assumes a type II' beta-turn conformation of Gly-Asp with a hydrogen bond between the C = O of Arg and the H-N of Ser. In addition, it was confirmed that two more hydrogen bonds are present in the RGD region of the Cys-RGD4 lysozyme. These results suggest that the conformation of the RGD-containing region is rigid and stable in the Cys-RGD4 molecule and that the type II' beta-turn structure of RGD is essential for binding to integrins with high affinity.
Decreased interleukin-6 level in the cerebrospinal fluid of patients with Alzheimer-type dementia.
We examined IL-6 levels in the cerebrospinal fluid (CSF) of patients clinically diagnosed with Alzheimer-type dementia (ATD) and with vascular dementia (VD) and of age-matched normal subjects. The IL-6 levels in the CSF of ATD, but not VD patients, were significantly decreased. In the early onset ATD patients (disease onset < 65 years), IL-6 levels were reduced to 21% of the control level. The IL-6 levels in the CSF were not associated with the severity of the dementia or the duration of the disease since the identification of the first symptoms.
Relation of angiographically defined coronary artery disease and plasma concentrations of insulin, lipid, and apolipoprotein in normolipidemic subjects with varying degrees of glucose tolerance.
We investigated the association between hyperinsulinemia and changes in lipid, lipoprotein, and apolipoprotein that would increase the risk of coronary artery disease (CAD) independent of glucose tolerance. A coronary angiogram was recorded in 127 male subjects, including 41 with normal glucose tolerance, 41 with impaired glucose tolerance, and 45 with non-insulin-dependent diabetes mellitus (NIDDM). Subjects were divided into 2 groups according to results: the group with CAD (n = 94) and the group with normal coronary arteries (n = 33). All subjects were normolipidemic (total cholesterol < 230 mg/dl and triglycerides < 150 mg/dl). The CAD group had a significantly lower plasma level of high-density lipoprotein (HDL) cholesterol and apolipoprotein A-I (apo A-I) and a higher level of apolipoprotein B (apo B) than the normal group with normal glucose tolerance. In considering subjects with impaired glucose tolerance or NIDDM, the CAD group had a significantly lower plasma level of HDL cholesterol and apo A-I and a significantly higher plasma level of total cholesterol, triglycerides, and apo B than the normal group. In each of the subjects with normal and impaired glucose tolerance, and NIDDM, the elevation of plasma insulin concentration during both the complete test period and the early phase of an oral glucose challenge was significantly higher in the CAD than in the normal group. In all subjects, graded reductions in HDL cholesterol and apo A-I and graded increases in plasma total cholesterol, triglycerides, and apo B were observed with increasing tertiles of the postglucose challenge measurements of insulinemia.(ABSTRACT TRUNCATED AT 250 WORDS)