[Surgical treatment of chronic constrictive pericarditis due to old tuberculosis; report of a case]

We experienced a case of pericardiectomy to treat constrictive pericarditis due to old tuberculosis. A 40-year-old woman was admitted to our hospital with dyspnea on exertion and edema of both legs. The chest computed tomography showed calcification of anterior ventricles. They were tightened up by calcified band. Subtotal pericardiectomy and removal of the calcification were performed without cardiopulmonary bypass. After the operation, symptoms were not disappeared in early phase. However, improvement for the patient was confirmed 3 months later.

Fatal propionic acidemia in mice lacking propionyl-CoA carboxylase and its rescue by postnatal, liver-specific supplementation via a transgene

Propionic acidemia (PA) is an inborn error of metabolism caused by the genetic deficiency of propionyl-CoA carboxylase (PCC). By disrupting the alpha-subunit gene of PCC, we created a mouse model of PA (PCCA(-/-)), which died in 24-36 h after birth due to accelerated ketoacidosis. A postnatal, liver-specific PCC expression via a transgene in a far lower level than that in wild-type liver, allowed PCCA(-/-) mice to survive the newborn and early infant periods, preventing a lethal fit of ketoacidosis (SAP(+)PCCA(-/-) mice). Interestingly, SAP(+)PCCA(-/-) mice, in which the transgene expression increased after the late infant period, continued to grow normally while mice harboring a persistent low level of PCC died in the late infant period due to severe ketoacidosis, clearly suggesting the requirement of increased PCC supplementation in proportion to the animal growth. Based on these results, we propose a two-step strategy to achieve an efficient PA prevention in human patients: a partial PCC supplementation in the liver during the newborn and early infant periods, followed by a larger amount of supplementation in the late infant period.

Involvement of thioredoxin in the regulation of growth hormone secretion in rat pituitary cell cultures

We report here an examination of the effect of thioredoxin (TRX) on the secretion of growth hormone (GH) from rat anterior pituitary cells in vitro. Treatment of rat pituitary cells with growth hormone-releasing factor (GRF), but not GH, led to a significant increase in intracellular TRX protein levels. GRF, recombinant human TRX (rhTRX), and a combination thereof were all shown to induce immediate GH secretion from pituitary cells, as evidenced by perifusion experiments. RhTRX, but not other reducing agents such as beta-mercaptoethanol and N-acetyl-L-cysteine, augmented GRF-stimulated and -unstimulated GH secretion from rat pituitary cells in a dose-dependent manner. RhTRX did not significantly affect the GH mRNA expression of pituitary cells stimulated in the presence or absence of GRF. In addition, rhTRX-augmented GH secretion was not significantly affected by the presence of cycloheximide. Collectively, these findings suggest that TRX is induced by stimulation with GRF and plays a regulatory role in GH secretion from rat anterior pituitary cells by enhancing the secretion of stored GH, rather than by the synthesis of GH.

Increased oxidative stress in rats with chronic nitric oxide depletion: measurement of urinary 8-hydroxy-2'-deoxyguanosine excretion

Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) has been reported to serve as a sensitive biomarker of oxidative stress. We examined the effect of chronic blockade of nitric oxide (NO) on urinary excretion of 8-OHdG in rats. Two types of NO synthase inhibitor were used: N(G)-nitro-L-arginine methyl ester (L-NAME) as a non-selective inhibitor and aminoguanidine (AG) as a selective inhibitor of the inducible isoform. Oral administration of L-NAME (20, 50 and 80 mg/dl of drinking water), but not AG (400 mg/dl), for 4 weeks induced systemic hypertension and a significant reduction in urinary excretion of NO2-/NO3-. Rats treated with L-NAME also showed a significant increase in urinary 8-OHdG excretion compared with the control animals. The effects of L-NAME (50 mg/dl) on blood pressure and urinary excretion of NO2/NO3- and 8-OHdG were restored by a large dose of L-arginine (2.0 g/dl). Chronic AG administration did not significantly alter urinary 8-OHdG excretion. On combining all the data, there was a significant negative correlation between urinary NO2-/NO,- and 8-OHdG. These observations suggest the importance of constitutive NO synthase activity in the maintenance of oxidant buffering capacity in rats. Oral administration of L-NAME may serve as a model of hypertension due to chronic NO deficiency with increased oxidative stress.

Morphological observation on cell death and phagocytosis induced by ultraviolet irradiation in a cultured human lens epithelial cell line

The purpose of this study is to observe dynamic morphological changes induced by ultraviolet (UV) irradiation in a cultured human lens epithelial cell line using electron microscopy, cell viability staining, time-lapsed videography and immunohistochemistry. Human lens epithelial cell line SRA 01-04 was cultured in Dulbecco's Modified Eagle Medium (DMEM) containing 20% fetal bovine serum. Subconfluent cells were irradiated under a bank of UV lamps, which emitted 275-400 nm radiation with a maximum at 310 nm. The UV intensity was 20 microW cm(-2)at dosages from 0 to 10 mJ cm(-2). Alterations in the morphology of the living cells were monitored and recorded with phase-contrast microscopy and time-lapsed videography. At different times, the cells were fixed and examined by transmission electron microscopy (TEM), diamidinophenolindole (DAPI) staining, and in situ immunohistochemistry using TdT-mediated dUTP-biotin nick end labeling (TUNEL). Cell viability was also assessed with crystal violet staining. At low doses of UV exposure (2-5 mJ cm(-2)), time-lapsed videography revealed definitive cell death that appeared to be primarily apoptotic. The dead cell debris was engulfed and phagocytosed by neighboring living cells. Phase-contrast microscopy and TEM demonstrated that, at UV 10 mJ cm(-2), the cells not only showed typical apoptosis such as nuclear membrane shrinkage, chromatin condensation, and fragmentation into apoptotic bodies, but also necrosis such as swelling of the nucleus and cell body, and disruption of the plasma membrane. In support, DNA staining and in situ immunohistochemical reactions in the UV irradiated cells were both positive. The phagocytotic process was also seen with TEM. UV irradiation thus appears to cause both apoptosis and necrosis in the cultured human lens epithelial cell line. Active migration and phagocytosis of the cells appear to be stimulated by UV-induced damage. These findings may also aid in the understanding of UV injury and repair mechanisms of lens epithelial cells in vivo.

Leukocyte-depleted continuous blood cardioplegia for coronary artery bypass grafting

Many cardiac surgeries are performed with blood cardioplegia. However, some studies suggest that activated neutrophils form blood cardioplegia can cause reperfusion injury. In this study we assessed myocardial protection using a leukocyte-depleted cardioplegic solution. Patients undergoing elective coronary artery bypass grafting (CABG) with continuous blood cardioplegia were divided into two groups: the LD group, which received leukocyte-depleted blood cardioplegia (n = 11); and the control group, which received nonfiltered blood cardioplegia (n = 11). IL-6, IL-8, CK-MB, and troponin T were measured in the coronary sinus blood immediately after the release of the aortic cross-clamp. Cytokine concentrations were also measured upon the patient's return to the ICU. The total dopamine and dobutamine doses, hemodynamic measurements after surgery, and the leukocyte filtration rate were also measured. During antegrade cardioplegia infusion, leukocytes were almost completely removed (filtration rate: 85.8+/-4.0%). However, during terminal warm cardioplegia, leukocyte removal decreased (filtration rate: 39.9+/-7.8%). Immediately after the release of the aortic cross-clamp, plasma CK-MB and troponin T concentrations were significantly lower in the LD group (17.7+/-1.9 U/l and 0.017+/-0.002 ng/ml, respectively) than in the control group (30.3+/-3.6 U/l and 0.072+/-0.029 ng/ml, respectively). The IL-6 and IL-8 concentrations were similar in the LD group and the control group. After the return to the ICU, the CK-MB and troponin T concentrations were similar in the two groups. No significant differences were found in the total doses of dopamine or dobutamine after surgery in the two groups (99+/-77 vs 101+/-128 microg/kg/min). No significant differences were found in the hemodynamic parameters after surgery in the two groups. In patients undergoing CABG with continuous blood cardioplegia, leukocyte-depleted blood cardioplegic solution may attenuate reperfusion injury.

[Three-channeled aortic dissection: selection of surgery based on the images]

Three patients with 3-channeled dissection were operated upon. Images of the dissection were enlargement of the false lumens, compression of the true lumen by enlarged false lumens and visceral arteries of false lumen origin. These prevent the use of cardiopulmonary bypass (CPB) and cause malperfusion of the viscera. Three-channeled dissecion is easy to rupture for its peculiar anatomy and total repair of the thoraco-abdominal aorta is mandatory. Fenestration brings functional recovery of malperfused viscera and enables the patients to be placed on CPB for total repair. Two patients underwent infrarenal and descending aorta fenestration followed by the total repair of thoraco-abdominal aorta successfully. A third patient has been placed on the strict CT follow-up following the infrarenal fenestration.

Lp85 calpain is an enzymatically active rodent-specific isozyme of lens Lp82

PURPOSES

To clone and sequence the cDNA for Lp85 calpain from young rat lens, and to test for Lp85 protein expression and proteolytic activity.

METHODS

RT-PCR and molecular cloning were performed on total RNA from 12 day-old rats. Lp85 protein expression was visualized by immunoblotting using a specific antibody developed to the unique peptide sequence in Lp85. Proteolytic activity was assessed by casein zymography. Transient expression of Lp85 and previously characterized lens-specific calpain Lp82 were separately performed in mammalian COS-7 cells.

RESULTS

The 2410-bp cDNA for rat lens Lp85 encoded a protein of 737 amino acid residues with a calculated molecular weight of 85.0 kDa and a predicted pI of 5.67. The amino acid sequence of Lp85 was identical to Lp82 except for an insert region of 28 amino acids in domain IV of the calcium-binding region. mRNA and protein for Lp85 were present only in rat and mouse lenses and not in other tissues or species. Lp85 protein concentrations were highest in the nuclear region, most concentrated in the insoluble fraction, disappeared with lens maturation, and Lp85 exhibited migration similar to Lp82 on native PAGE gels. Lp85 was enzymatically active when expressed in COS-7 cells.

CONCLUSIONS

Lp85 is a newly classified, lens- and rodent-specific, enzymatically active, member of the AX1 (alternative exon 1) subclass of calpains. In conjunction with Lp82 and m-calpain in lens, Lp85 may be responsible for proteolysis during normal lens development and maturation or during cataract formation in young rodents.

[Double chambered right ventricle in a 62-year-old female: a surgical case report]

A 62-year-old female was admitted with a chief complaint of transient syncope on exertion. Angiography in right ventricle revealed a defect caused by an anomalous muscle bundle and a pressure gradient of 151 mmHg was observed between the two chambers by cardiac catheterization. Resection of the anomalouse muscle bundle was undertaken using a lower median sternotomy starting at the 2nd intercostal space level and through the outflow tract right ventriculotomy. Patch plasty was also undertaken in the outflow tract. Post-operative course was uneventful and pressure gradient had disappeared at the post-operative catheterization. A rare case of DCRV in a 62-year-old patient with a pressure gradient of 151 mmHg in the right ventricle was reported.

Modifications in electrospray tandem mass spectrometry for a neonatal-screening pilot study in Japan

In a neonatal-screening pilot study for inherited disorders in organic acid and amino acid metabolism, we analyzed butyrated acylcarnitines and amino acids in blood spots of more than 20,000 newborns by electrospray tandem mass spectrometry. In order to screen urea cycle disorders, we performed multiple scanning functions with additional stable isotope-labelled internal standards, since such reported functions as neutral loss of m/z 102 or 109 for butyrated amino acids were not sufficient. Arginine levels were measured with arginine-13C6. Hypocitrullinemia for the screening of some urea cycle disorders was detectable by measurement with synthesized citrulline-d6, although we did not find any such disorders. In the acylcarnitine analysis, we found a patient with propionic acidemia, who has been treated effectively. The increasing false positive rate due to the use of pivalic acid-containing antibiotics in the diagnosis of isovaleric acidemia was a problem in Japan.

[Aortic valve operations through an upper partial sternotomy]

The median sternotomy has been accepted as the most common approach to the heart, because this approach is easily opened and closed, and easy access to the entire heart is possible. Following the pioneering work by Cosgrove and colleagues of using a parasternal incision for aortic and mitral valve operations, several reports suggested that modified minimal access procedures are likely to be associated with reduced postoperative discomfort and faster recovery. Since July 1997, we have used an upper partial sternotomy and a limited skin incision for isolated aortic valve replacement (AVR) at our hospital. To demonstrate the benefits of this approach, we compared 14 AVR operations using our minimal access incision (group M) with 19 patients undergoing isolated AVR using a conventional sternotomy (group F). In the minimal access group of patients, a small skin incision was made from the second intercostal space to the fourth rib. The pectralis major and intercostal muscle was freed from the sternum, and then a transverse half sternotomy was made in the fourth intercostal space using a striker without injury to the right internal mammary artery. A median partial sternotomy from the supersternal notch to the level of the fourth intercostal space. Cardiopulmonary bypass was connected through the same access site to avoid cannulation of both groins. Conversion to median sternotomy was not necessary in any patient including reexploration for postoperative bleeding. There was no operative mortality, stroke, aortic dissection and perivalvular leaks due to technical factors. In group F, wound infection occurred in 1 patient. One patient in group M required reoperation to control postoperative bleeding. Although mean duration of operation, cardiopulmonary bypass, and cross clamp time in group M was not prolonged, the initiation of cardiopulmonary bypass and aortic crossclamp was delayed by difficulties of cannulations. The distance between the transverse sternotomy (lower edge of divided sternum) and the midpoint of aortic valve annulus was correlated with mean duration of cardiopulmonary bypass and cross clamp time. Our experience demonstrates that isolated AVR through an upper partial sternotomy allows the same quality operations as the full sternotomy, although more clinical experience is required to clarify the benefits of this approach. Excellent exposure of the aortic valve through a partial sternotomy may be attained, if an adequate approach can be selected by the position of aortic valve.

Lp82 is the dominant form of calpain in young mouse lens

The purpose of this study was to characterize Lp82 calpain in normal mouse. Lp82 is a lens-specific, calcium-activated isozyme from the calpain super family of cysteine proteases (EC 34.22.17). RT-PCR and molecular cloning were performed on total RNA from 12 day-old mice. Lp82 and m-calpain protein levels and proteolytic activities in lenses were measured by casein zymography, immunoblotting, and ELISA after partial purification by DEAE-HPLC. The 2334-bp cDNA encoding for mouse Lp82 contained a single large open reading frame encoding a protein of 709 amino acid residues with a calculated molecular weight of 82.2 kDa and a predicted pI of 5.8. The amino acid sequence of mouse lens Lp82 was 99% homologous to rat lens Lp82. As in rat, mouse lens Lp82 showed a unique N -terminus and deletion of the IS1 and IS2 regions. In contrast to rat, Lp82 was the dominant calpain in young mouse lens. Lp82 was lens-specific, and the lens nucleus contained the highest specific activity of Lp82 and very little m-calpain. Endogenous Lp82 in lens soluble proteins was activated by addition of calcium and caused limited proteolysis of crystallins even in the presence of large amounts of recombinant domain I from the natural calpain inhibitor calpastatin. Loss of Lp82 protein accompanied aging of mouse lens. Lp82 may be responsible for a major portion of crystallin proteolysis occurring during normal lens development and maturation, or during cataract formation in young mice.

Post-parturition infectious endocarditis in a patient with a normal mitral valve

A 29-year-old woman with no history of heart disease was admitted for the treatment of congestive heart failure. Six months earlier, she had given birth, then 20 days later developed a fever and cardiac failure ensued. An echocardiogram demonstrated severe mitral valve regurgitation. Her blood cultures were positive, and we made a diagnosis of mitral valve regurgitation due to infectious endocarditis. Despite treatment for congestive heart failure and antibiotic therapy, resulting in negative blood cultures, her congestive heart failure did not improve, and vegetation on the mitral valve was observed by echocardiography. We successfully removed the infected tissue with mitral valve plasty.

Identification of a phosphopeptide in bovine alpha s1-casein digest as a factor influencing proliferation and immunoglobulin production in lymphocyte cultures

Digestion of bovine alpha s1-casein with bovine trypsin produced peptide(s) with an inhibitory effect on concanavalin A-induced proliferation of mouse spleen cells. One of these peptides was isolated from the alpha s1-casein digest following ultrafiltration, hydroxyapatite chromatography and reversed-phase HPLC, and amino acid composition and sequence analyses showed it to be sequence 59-79 from the phosphoserine-rich region of alpha s1-casein. The isolated peptide significantly inhibited the concanavalin A-induced proliferation of mouse spleen cells and rabbit Peyer's patch cells, whereas it enhanced the lipopolysaccharide- and phytohaemagglutinin-induced proliferation of both cells. The peptide displayed mitogenic activity in the cell cultures without the commercial mitogen, and significantly enhanced immunoglobulin production. Moreover, residues 1-25 from the phosphoserine-rich region of bovine beta-casein had a similar effect on the proliferation of mouse spleen cells and rabbit Peyer's patch cells stimulated or not stimulated by the commercial mitogen. These results indicate that caseinophosphopeptides may act as a humoral immunostimulator in cell cultures.

Lp82 calpain during rat lens maturation and cataract formation

PURPOSE

To measure changes in levels of Lp82 during maturation and selenite cataract formation in rat lens. Lp82 is a lens-specific, calcium-activated isozyme from the calpain family of cysteine proteases (EC 34.22.17).

METHODS

Competitive RT-PCR was used to assess Lp82 and m-calpain mRNA concentrations. Immunoblotting and ELISA after DEAE chromatography measured Lp82 and m-calpain protein levels. Casein zymography assessed proteolytic activities in regions and whole lenses from maturing rats.

RESULTS

Levels of Lp82 mRNA, protein, and caseinolytic activity decreased more rapidly during maturation of rat lens than for m-calpain. Unexpectedly, the water-insoluble fraction of rat lens contained enzymatically active Lp82. Selenite injection also caused major loss of Lp82 protein during cataract formation.

CONCLUSIONS

Lp82 is a proteolytic enzyme likely functioning in early lens development and maturation. The rapid loss of Lp82 activity during lens maturation is probably caused by three factors: autodegradation associated with the proteolysis of soluble and insoluble proteins occurring in the rat lens nucleus, association of Lp82 with the lens insoluble fraction, and loss of Lp82 mRNA. Lp82 may function early in lens maturation along with m-calpain, which then is predominant in the latter stages of maturation. Proteolysis in selenite cataract is partially caused by over-activation of Lp82.

Renal water channel expression in newborns: measurement of urinary excretion of aquaporin-2

Aquaporin-2 (AQP-2) encodes the vasopressin-regulated "water channels" of the renal collecting duct and is excreted in human urine. We measured urinary excretion of AQP-2 by radioimmunoassay in 15 term and 10 preterm infants on day 1 and day 4 of life to determine the molecular basis of water balance during the newborn period. AQP-2 was detectable in the urine of term and preterm newborns, but AQP-2 excretion was severalfold less than the reported level in normal adults. Urinary excretion of AQP-2 significantly decreased postnatally, in parallel with a reduction in urine osmolality and arginine vasopressin (AVP) excretion. Urinary AQP-2 correlated positively and significantly with urine osmolality on days 1 and 4 and with AVP on day 1 in both groups. No significant differences were detected in AQP-2 levels between term and preterm newborns. Our findings suggest that vasopressin-regulated water channels are expressed in the renal collecting duct of both term and preterm newborns, although to a lesser extent as compared with adults, and these channels encoded by AQP-2 contribute to the urine concentrating power of the newborn kidney.

[Thoracoabdominal aortic repair without using assisted bypass]

A 41-year-old man, who had undergone descending aortic repair following rupture of the DeBakey type III aortic dissection, underwent thoracoabdominal aneurysm repair 1 year after the first surgery. The operation was performed by partial-clamping and single crossclamping without using assisted bypass or shunt, in order to minimize bleeding ensuing the re-thoracotomy and dissection between lung and the graft.

[Re-do surgery with minimally invasive cardiac surgery (MICS): mitral valve replacement 6 years after open mitral commissurotomy]

A 60-year-old man, who had undergone open mitral commissurotomy 6 years ago, underwent re-do surgery (mitral valve replacement) with minimally invasive cardiac surgery (MICS), using lower partial sternotomy to the height of the right side second intercostal space. Cannulation of the heart was carried out placing a cannula directly into the superior vena cava and a second cannula in the inferior vena cava via the right atrium. Arterial return was through the ascending aorta. Cardioplegia was administered directly into the ascending aorta with intermittent perfusion. Valve replacement was performed by opening directly right side left atrium.

Protein for Lp82 calpain is expressed and enzymatically active in young rat lens

mRNA for a newly discovered isoform of calpain, termed Lp82, was recently discovered in young rat lens. The purpose of the present experiments was to test for expression of Lp82 protein. Casein zymography after incubation with calcium was used to detect Lp82 proteolytic activity in regions of lenses from young rats. Lp82 protein was detected by immunoblotting or by ELISA after DEAE-5PW chromatography using a polyclonal antibody generated to a peptide sequence in Lp82. Northern blot analysis assessed expression of Lp82 mRNA. Four results demonstrated expression of Lp82 protein; (1) immunoblot reactivity at the predicted molecular mass of 82 kDa, (2) a unique band of calcium-activated lysis in casein zymograms, (3) partial purification and retention of activity from a single Lp82 peak on DEAE-5PW chromatography, and (4) positive immunoblotting and Northern blot analysis only in lens and not in other rat tissues. These results showed that Lp82 protein is lens-preferred, relatively abundant in young rats (especially nucleus), and enzymatically active. Proteolysis of crystallins in the nucleus of young rat lens during normal maturation and cataract formation, formerly attributed solely to m-calpain, may in fact be due to concerted action of both lens Lp82 and ubiquitous m-calpain.

Urinary excretion of aquaporin-2 in term and preterm infants

Aquaporin-2 (AQP-2) is a vasopressin-regulated water channel of the renal collecting duct and is excreted in human urine. We measured the urinary excretion of AQP-2 by radioimmunoassay in 14 term and 12 preterm infants aged 1 month. Excretion of AQP-2 was low compared with adults, and correlated significantly with urine osmolality in preterm infants. Our results demonstrate that AQP-2 water channels are expressed in the renal collecting duct of both term and preterm infants.

[A case report of mitral valve replacement using a parasternal incision (minimally invasive cardiac surgery) with pleuritis tuberculosa and after esophagus operation]

A 68-year-old man underwent mitral valve replacement because of mitral regurgitation (prolaps of anterior mitral leaflet) using parasternal incision (Delos M. Cosgrove, minimally invasive surgery). He had been treated as pulmonary tuberculosis previously and had undergone esophagus operation using stomach role reconstruction beneath the sternum four years before the mitral valve procedure. We could not select median-sternotomy as an approach due to stomach role beneath the sternum, nor left posterolateral thoracotomy because of the heavy left-side pleural adhesion. Cardio-pulmonary bypass cannulations were performed through the same incision, because severe atherosclerosis was found at the distal arteries of the abdominal aorta.

Nitric oxide in septic and aseptic meningitis in children

To investigate the involvement of nitric oxide (NO) in childhood meningitis, we measured the concentrations of NO2- (a stable metabolite of NO) in serial samples of cerebrospinal fluid (CSF) from 11 children with septic and 7 with aseptic meningitis and 26 control patients without meningitis. The mean concentration of NO2- in samples obtained during the early stages of septic meningitis, but not aseptic meningitis, was significantly higher than in control samples. Clinical and laboratory improvement following administration of antibiotics and dexamethasone was associated with a fall in CSF [NO2-] to normal levels in these patients. CSF [NO2-] remained almost consistently within the normal range in patients with aseptic meningitis. Our findings indicate that NO production is enhanced in the CSF compartment of children with septic meningitis and support the hypothesis that NO is involved in the pathophysiology of septic meningitis.

Assessment of endogenous nitric oxide formation in newborns: measurement of urinary nitrite and nitrate concentrations

We measured the urinary nitrite and nitrate (NOx-) excretion, an index of endogenous nitric oxide formation, in term and preterm newborns on the 1st and 4th days of age. In the infants of both groups, the urinary NOx- excretion significantly increased from the 1st to the 4th day. The urinary NOx- excretion in preterm infants was significantly higher as compared with term babies on both days. Furthermore, the urinary NOx- excretion was significantly elevated in preterm infants with respiratory distress syndrome as compared with those without cardiopulmonary complications on the 4th day. These changes of urinary NOx- excretion in newborns strongly suggest the presence of an active physiological role for nitric oxide in the circulatory adaptation to extrauterine life.

[The comparison of tepid and moderate hypothermic cardiopulmonary bypass in cardiac surgery]

Normothermic cardiopulmonary bypass (CPB) is being increasingly used at some institutions. Patients undergoing normothermic CPB have a higher systemic oxygen demand and may be at higher risk for ischemic injury. This study was designed to confirm the clinical efficacy and safety of tepid hypothermic CPB. Thirty-six patients undergoing open heart surgery between June 1993 and August 1994 were divided into two groups: tepid (n = 18, 32 degrees C) and moderate (n = 18, 26 degrees C) hypothermic CPB. There were no significant differences in preoperative and perioperative patients characteristics between the two groups. The mean aortic cross-clamp time did not differ between two groups, but the mean CPB time was significantly shorter in tepid hypothermic patients. Serum lactate after CPB and lactate/pyrvate ratio during CPB in tepid hypothermic patients were significantly lower than in moderate hypothermic patients. The mixed venous oxygen saturation in tepid hypothermic patients was significantly lower however, it was maintained at levels more than 70% during CPB. This study suggests that tepid hypothermic CPB is a safe and effective alternative to moderate hypothermic CPB for patients undergoing open heart surgery. Previous reports have documented that patients undergoing normothermic CPB are at greater risk for cerebral desaturation. We should evaluate cerebral venous oxygen saturation during tepid hypothermic CPB before the induction of normothermic CPB.

Chronic erythropoietin treatment enhances endogenous nitric oxide production in rats

To examine the effect of chronic administration of recombinant human erythropoietin (rHuEPO) on endogenous nitric oxide (NO) activity, we treated Sprague-Dawley rats with rHuEPO (100 IU kg-1 or 300 IU kg-1) or a corresponding vehicle for 2 weeks, administered subcutaneously on alternate days. Treatment elicited increases in haematocrit and systolic blood pressure in a dose-dependent fashion. Simultaneous administration of NG-nitro-L-arginine methyl ester (L-NAME, 20 mg dl-1 of drinking water), but not aminoguanidine (400 mg dl-1), induced a further significant rise in blood pressure. The effect of L-NAME was inhibited by a large dose of L-arginine (2.0 g dl-1). Polycythaemia and hypertension induced by chronic rHuEPO therapy were associated with increased urinary NO2- and NO3- (NOx-) excretion, while co-administration of L-NAME, but not aminoguanidine, reduced NOx- excretion. Our results indicate that chronic rHuEPO treatment has a significant pressor effect, but induces a compensatory increase in the steady-state release of NO by constitutive NO synthase in normal rats. Such enhanced NO synthesis may act as a protective mechanism against the hypertensive effect of rHuEPO.

Identification of genetic mutations in Japanese patients with fructose-1,6-bisphosphatase deficiency

Fructose-1,6-bisphosphatase (FBPase) deficiency is an autosomal recessive inherited disorder and may cause sudden unexpected infant death. We reported the first case of molecular diagnosis of FBPase deficiency, using cultured monocytes as a source for FBPase mRNA. In the present study, we confirmed the presence of the same genetic mutation in this patient by amplifying genomic DNA. Molecular analysis was also performed to diagnose another 12 Japanese patients with FBPase deficiency. Four mutations responsible for FBPase deficiency were identified in 10 patients from 8 unrelated families among a total of 13 patients from 11 unrelated families; no mutation was found in the remaining 3 patients from 3 unrelated families. The identified mutations included the mutation reported earlier, with an insertion of one G residue at base 961 in exon 7 (960/961insG) (10 alleles, including 2 alleles in the Japanese family from our previous report [46% of the 22 mutant alleles]), and three novel mutations--a G-->A transition at base 490 in exon 4 (G164S) (3 alleles [14%]), a C-->A transversion at base 530 in exon 4 (A177D) (1 allele [4%]), and a G-->T transversion at base 88 in exon 1 (E30X) (2 alleles [9%]). FBPase proteins with G164S or A177D mutations were enzymatically inactive when purified from E. coli. Another new mutation, a T-->C transition at base 974 in exon 7 (V325A), was found in the same allele with the G164S mutation in one family (one allele) but was not responsible for FBPase deficiency. Our results indicate that the insertion of one G residue at base 961 was associated with a preferential disease-causing alternation in 13 Japanese patients. Our results also indicate accurate carrier detection in eight families (73%) of 11 Japanese patients with FBPase deficiency, in whom mutations in both alleles were identified.

Experimentally induced acute hyperinsulinemia stimulates endogenous nitric oxide production in humans: detection using urinary NO2-/NO3-excretion

Insulin-mediated glucose metabolism in skeletal muscle is associated with a proportional increase in muscle perfusion. The vasodilatory effect of insulin is thought to be mediated in part by endothelium-derived nitric oxide (NO). The present study was performed to determine whether acute hyperinsulinemia has any stimulatory effect on endogenous NO production in humans. Bolus intravenous injection of insulin (0.1 IU/kg body weight) caused a significant increase in urinary excretion of NO2-/NO3- together with a significant decrease in blood pressure, whereas saline infusion alone had no effect on these parameters. The increased NO response to insulin was almost comparable to that obtained with infusion of 30 g L-arginine. The acute effect of hyperinsulinemia on endogenous NO formation supports the concept that NO may mediate the vasodilatory action of insulin in humans.

Endogenous nitric oxide production in Kawasaki disease

To evaluate in vivo nitric oxide production in Kawasaki disease (KD), urinary nitrite/nitrate (NOx) excretion was measured in 8 children with KD (age 1.1-2.7 years). Urinary NOx excretion was 0.66 +/- 0.22 mmol mmol-1 creatinine (mean +/- SD) in the 8 children with KD in the initial stages. The levels were significantly increased compared with those of 12 age-matched healthy control subjects (0.35 +/- 0.08 mmol mmol-1 creatinine). Urinary Nox excretion was serially determined in four patients. For each patient, there was a further rise in urinary NOx excretion from baseline levels coincident with the administration of intact-type gammaglobulin and aspirin. With clinical and laboratory improvement, however, urinary NOx excretion declined to the normal range. These findings suggest that endogenous nitric oxide production is enhanced in children with acute KD. Further studies are needed to clarify the role of nitric oxide in the pathogenesis and clinical course of KD.

A case of dyshormonogenetic goiter complicated with growth hormone deficiency

A 17-year-old male patient with dyshormonogenetic goiter complicated with follicular adenoma and growth hormone deficiency is described. He had short stature (-2.3 SD), diffuse goiter and a particularly large nodule in the right lobe of the thyroid gland. The endocrinological studies revealed slight hypothyroidism. He underwent surgical removal of the tumor, diagnosed histopathologically as follicular adenoma, embryonal type; and the diffuse goiter was diagnosed as dyshormonogenetic goiter. It was speculated that long-term hypersecretion of thyroid stimulating hormone (TSH) caused adenoma in the thyroid gland. Although the goiter disappeared after oral thyroxine replacement therapy, his height gain remained poor. Then, he was diagnosed partial growth hormone deficiency, and growth hormone therapy improved his height gain. It has been reported that a high percentage of patients with congenital hypothyroidism have additional anomalies. This is, however, the first reported case of dyshormonogenetic goiter complicated with growth hormone deficiency.

Urinary nitrite/nitrate excretion in infancy: comparison between term and preterm infants

We measured urinary nitrite/nitrate (NOx-) excretion, an index of endogenous nitric oxide formation, in term and preterm infants aged 1 week and 1, 4, 7 months. In normal term infants, urinary NOx excretion increased from 1 week to 1 month and then decreased until 4 months where it stabilized thereafter. Urinary NOx- excretion in preterm infants was significantly higher compared with term infants at 1 week of age. This finding suggests that the nitric oxide pathway in preterm infants may be activated compared with term infants in early life. With the reference values obtained in this study, this urinary marker can now be used for identifying infants with abnormal nitric oxide production.

[Application of extracorporeal membrane oxygenation for respiratory failure following septic pulmonary emboli]

A 23-year-old man, diagnosed as ventricular septal defect in childhood, was hospitalized with right-sided infective endocarditis. He developed acute respiratory failure following septic pulmonary emboli and underwent urgent surgical treatment, because vigorous medical treatment was ineffective. Extracorporeal membrane oxygenation was performed to maintain arterial blood oxygen tension after cardiopulmonary bypass and the patient was weaned from ECMO after 36 hours. Postoperatively, mechanical ventilation for respiratory failure was needed continuously and pleural leaks due to lung injuries were increased. The reduction of pleural leaks by surgical closure of fistula and plication of the cyst decreased gas exchange impairment. To our knowledge, application of extracorporeal membrane oxygenation for septic pulmonary emboli is unprecedented.

[A surgical case report of angina pectoris with multiple coronary giant aneurysms]

A 47-year-old man with sever angina pectoris was referred for surgery. Preoperative coronary angiogram revealed giant multiple aneurysms of RCA (Seg 1-Seg 3) and LCX (Seg 11) and LAD (Seg 6). Stenoses were found distal to aneurysm, 90% in RCA-Seg 4, CX-Seg 11, 100% in LAD- Seg 6 and DX-Seg 9 and OM-Seg 12, with collaterals from RCA to LAD. Left ventlicle contracted poorly with the EF of 36 due to anteroseptal infarction. Coronary artery bypass grafting were performed to LAD using a LITA, to DX and LCX using a SVG in the sequential fashion. Postoperative coronary cineangiogram demonstrated that all grafts were patent and multiple giant coronary aneurysms resembled coronary arterial changes of Kawasaki's disease.

Effect of nitric oxide synthase inhibitors on bone metabolism in growing rats

We examined the effects of chronic nitric oxide (NO) blockade on bone mineral status in growing rats. Oral administration of NG-nitro-L-arginine methyl ester (L-NAME) for 4 wk caused hypertension and a significant reduction in urinary NO2- and NO3- excretion. Four-week oral aminoguanidine (AG, 400 mg/dl of drinking water) did not alter blood pressure but caused a significant decrease in urinary NO2- and NO3-. Rats treated with L-NAME at doses of 20 and 50 mg/dl had normal bone mineral mass in the lumbar spine, but the highest dose (80 mg/dl) caused a slight decrease in bone mass. Chronic AG induced a significant spine osteopenia. This effect of AG was abolished by the simultaneous administration of L-arginine (2.0 g/dl). AG-induced osteopenia was associated with a significant increase in urine excretion of collagen cross-links with normal serum osteocalcin. These findings indicate that chronic AG administration can cause an imbalance between bone resorption and formation, resulting in a decrease in bone mass in growing rats, and suggest that NO produced by inducible NO synthase plays an important role in basal osteoclast bone degradation activity in vivo.

Prenatal diagnosis of organic acidemias based on amniotic fluid levels of acylcarnitines

Acylcarnitines in amniotic fluid samples were analyzed for the prenatal diagnosis of propionic acidemia, methylmalonic aciduria, isovaleric acidemia, and glutaric aciduria by electrospray tandem mass spectrometry. Although the levels of the specific acylcarnitine between affected and unaffected cases showed an overlap, the ratios of propionylcarnitine to 4-carbon acylcarnitine levels for propionic acidemia and methylmalonic aciduria, those of isovalerylcarnitine to propionylcarnitine for isovaleric acidemia, and those of glutarylcarnitine to propionylcarnitine for glutaric aciduria type I were shown to be reliable indicators in the prenatal diagnosis. In addition, it is suggested that the combination of the ratios of glutarylcarnitine, isovaleryl-carnitine, and hexanoylcarnitine to propionylcarnitine may be useful for the prenatal diagnosis of glutaric aciduria type II.

Inhibition of proliferative responses of mouse spleen lymphocytes and rabbit Peyer's patch cells by bovine milk caseins and their digests

The modulating effect of bovine milk casein components and their digests on the proliferative responses of mouse spleen lymphocytes and rabbit Peyer's patch cells induced or not induced by mitogens has been studied with a colorimetric assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. All the casein components and their digests tested had little mitogenic effect on the proliferative responses of mouse spleen lymphocytes and rabbit Peyer's patch cells. Intact kappa-casein significantly inhibited the proliferative responses of mouse spleen lymphocytes and Peyer's patch cells induced by mitogens such as lipopolysaccharide from Salmonella typhimurium, concanavalin A, phytohaemagglutinin and pokeweed mitogen. In contrast, intact alpha s1-casein and beta-casein had little effect. kappa-Casein had an inhibitory effect after digestion by pancreatin or trypsin, but not after pepsin or chymotrypsin digestion. Both pancreatin and trypsin digests of alpha s1-casein and beta-casein significantly inhibited the proliferative responses of mouse spleen lymphocytes and rabbit Peyer's patch cells induced by mitogens, whereas pepsin and chymotrypsin digests of both caseins were without effect. Moreover, the trypsin digest of each casein component had an inhibitory effect on mouse spleen lymphocyte proliferation in the absence of mitogen. Since trypsin is a major proteinase in pancreatin, the substrate specificity of trypsin seems to be important for the formation of the inhibitory peptides from casein components. These observations suggest that intact kappa-casein and some peptides formed from milk casein components by the action of trypsin may suppress the immune responsiveness of neonates.