Measurement of myocardial fractional flow reserve during coronary angioplasty in patients with old myocardial infarction

Although myocardial fractional flow reserve (FFRmyo) has been demonstrated to be a useful index for determining functional significance of coronary stenosis, the data in previous studies was derived from a highly selected group of patients. The aim of this study was to investigate the value of FFRmyo in a more clinically relevant group of patients, especially in patients who also had resistance vessel dysfunction. We measured FFRmyo in 20 consecutive patients who had undergone elective coronary angioplasty. FFRmyo was calculated by the ratio of Pc/Pa during intracoronary adenosine 5'-triphosphate (ATP; 50 micrograms in the left coronary and 20 micrograms in the right coronary artery) induced maximal hyperemia, where Pa represents mean aortic pressure obtained by the guiding catheter and Pc represents mean distal coronary pressure measured by a 2.1 F infusion catheter. In total, 21 vessels were dilated and 14 of them were infarct-related arteries. The percent diameter stenosis significantly decreased from 80 +/- 14% to 27 +/- 17%, and the FFRmyo increased significantly from 0.46 +/- 0.18 to 0.77 +/- 0.15 after angioplasty. There was no significant differences in the FFRmyo between vessels with previous myocardial infarction and those without, after angioplasty (0.78 +/- 0.18 vs. 0.76 +/- 0.08). There was a significant correlation between the percent diameter stenosis and FFRmyo before (r = 0.83, P < 0.001) and after (r = 0.64, P < 0.01) angioplasty. In conclusion, FFRmyo significantly improved immediately after angioplasty in vessels with myocardial infarction as well as those without. These results led us to suggest the usefulness of FFRmyo in patients who had both epicardial stenosis and resistance vessel dysfunction. The significant correlation between FFRmyo and quantitative coronary arterial diameter stenosis would further support the more widespread use of FFRmyo in the clinical setting.

Diagnosis of bladder cancer by analysis of the allelic loss of the p53 gene in urine samples using blunt-end single-strand conformation polymorphism

The novel approach of blunt-end single-strand conformation polymorphism (SSCP) has been applied in the analysis of urine samples from bladder-cancer patients for detecting loss of heterozygosity (LOH) of 3 polymorphic markers in the p53 gene. Of the 28 urine samples examined by SSCP analysis of blunt-ended DNA fragments using a fluorescence-based automated sequencer, 16 were informative in more than 1 of the 3 polymorphic markers at the p53 locus and 8 (50.0%) showed allelic loss of the p53 gene. In analysis of resected tumor tissues, LOH of the p53 gene was detected in 8 of 8 informative samples (100%) with T1 and higher stages and/or Grade 2 and Grade 3 tumors, while it was detected in 6 (75.0%) urine samples obtained from these 8 patients. This new diagnostic modality enables sensitive detection of tumor cells in urine samples and would be applicable for diagnostic bladder cancer with invasive character.

Acute myocardial infarction in a patient during dobutamine stress echocardiography

We report the case of a patient who developed an acute anteroseptal and inferior myocardial infarction during dobutamine stress echocardiography. The proposed mechanism for this event is discussed based on results obtained during emergency coronary angioplasty and subsequent clinical findings.

Scintigraphic evaluation along with CT and MR images in a case of huge gravitation abscess

The authors presented a rare case of huge gravitation abscess. 67Ga scintigraphy was useful in the evaluation of the extent and activity of the disease. CT showed clearly the location and shape of the abscess. Enhanced MRI showed vertebral lesions as characteristic geographic and ring-like enhancement.

Rabbit DNase I: purification from urine, immunological and proteochemical characterization, nucleotide sequence, expression in tissues, relationships with other mammalian DNases I and phylogenetic analysis

DNase I from rabbit urine was purified approx. 3600-fold to apparent homogeneity with a 41% yield by affinity chromatography utilizing DNA-cellulose; the purity of the final preparation was assessed by SDS/PAGE, lack of contamination by other nucleases and production of a monospecific antibody against the enzyme. Although the proteochemical and enzymological properties of the purified enzyme resembled those of other mammalian DNases I, the enzymic activity of rabbit DNase I was less efficiently inhibited by monomeric actin than was that of human DNase I, probably due to substitution of an amino acid residue involved in actin binding (Tyr-65 to Phe). The effects of specific antibodies to human, rabbit and rat DNases I on the activities of the corresponding purified enzymes revealed that human DNase I lies between the rat and rabbit enzymes with regard to its immunological properties. An 1158 bp full-length cDNA encoding rabbit DNase I was constructed from the total RNA of rabbit pancreas using a combination of reverse transcriptase-PCR and rapid amplification of cDNA ends, followed by sequencing. This identified a 17- or 21-amino-acid signal sequence, with the mature enzyme containing 260 amino acids and a single N-glycosylation site at Asn-18. The amino acid sequence deduced from the cDNA sequence exactly matched that determined proteochemically from the purified enzyme up to residue 20. A systematic survey of DNase I distribution as measured by both enzymic activity and DNase I gene transcripts in 12 rabbit tissues showed the pancreas and parotid gland to produce equivalent levels, higher than those in other tissues. Enzymic activity and DNase I gene expression levels in each tissue correlated well. The results of phylogenetic and sequence identity analysis, immunological properties and tissue-distribution patterns of DNase I indicated a closer relationship between the rabbit and human enzymes than for other mammalian DNases I. Furthermore, differences between the enzymic activities expressed in mammalian parotid gland and pancreas suggest that the distribution of DNase I in mammalian tissue is species-specific.

Exercise-induced neurally mediated syncope

We describe a 16-year-old female referred for evaluation of syncope associated with competitive long distance running. She had experienced 4 episodes of syncope during competitive long distance racing. The syncope associated with marked bradycardia and asystole was demonstrated by head-up tilt testing without isoproterenol infusion. Oral propranolol therapy failed to prevent the syncope. Oral disopyramide therapy, however, prevented the syncope induced by both head-up tilt testing and competitive long distance racing. Caution should be urged in evaluating athletes with syncope, especially in the pediatric age group, because the cause of the syncope may result from life-threatening disorders such as cardiomyopathy, long QT syndrome, or exercise-induced arrhythmias. The head-up tilt test is an important diagnostic tool for the evaluation of exercise-associated syncope.

Effect of LDL-apheresis on the pharmacokinetics of the lipophilic antilipidemic agent probucol

The effect of LDL-apheresis on the pharmacokinetics of antilipidemic agents has not been evaluated thoroughly. In this study, we investigated the effect of LDL-apheresis on the pharmacokinetics of probucol, a lipophilic antilipidemic agent, by studying its distribution and changes in the blood concentration of probucol after LDL-apheresis. The concentrations of lipoproteins were measured before and after LDL-apheresis in eight patients with familial hypercholesterolemia taking probucol. Concentrations of probucol in the various lipoprotein fractions and plasma were measured by HPLC. The serum concentrations of probucol before and after LDL-apheresis were 39.8 +/- 3.3 and 16.5 +/- 1.6 micrograms/ml, and the correlation coefficient between the changes in the serum probucol concentration and those in the serum cholesterol concentration before and after LDL-apheresis was significant (r = 0.73, P < 0.01). Changes in the probucol and cholesterol concentrations after LDL-apheresis were mainly found in the LDL fraction. The calculated reductions in the serum contents of probucol and cholesterol were similar to the contents of probucol and cholesterol in the irrigation fluid of the dextran sulfate column. These data suggest that changes of probucol concentration in plasma by LDL-apheresis are mainly due to reductions in the LDL fraction.

Hydroxyapatite-coating on titanium arc sprayed titanium implants

We developed a new titanium spray technique using an inert gas shielded arc spray (titanium arc spray). Hydroxyapatite (HA)-coating can be applied to the implant without any surface pore obstruction after the rough surface is made by this technique. Scanning electron microscopy (SEM) of various porous implant surfaces after HA-coating revealed that the bead and fiber metal-coated implants had either a pore obstruction or an uneven HA-coating. On the other hand, the titanium arc sprayed implant demonstrated an even HA-coating all the way to the bottom of the surface pore. In the first set of animal experiments (Exp. 1), the interfacial shear strength to bone of four kinds of cylindrical Ti-6A1-4V (Ti) implants were compared using a canine transcortical push-out model 4 and 12 weeks after implantation. The implant surfaces were roughened by titanium arc spray (group A-C) and sand blasting (group D) to four different degrees (roughness average, Ra = group A: 56.1, B: 44.9, C: 28.3, D: 3.7 microns). The interfacial shear strength increased in a surface roughness-dependent manner at both time periods. However, the roughest implants (group A) showed some failed regions in the sprayed layers after pushout test. In the second set of animal experiments (Exp. 2), four kinds of Ti implants; HA-coated smooth Ti (sHA) with Ra of 3.4 microns, bead-coated Ti (Beads), titanium arc sprayed Ti (Ti-spray) with Ra of 38.1 microns and HA-coated Ti-spray (HA + Ti-spray) with Ra of 28.3 microns were compared using the same model as that in Exp. 1. The interfacial shear strength of HA + Ti-spray was significantly greater than that of sHA and Beads at both time periods, and that of Ti-spray at 4 weeks. Although a histological examination revealed that HA-coating enhanced bone ingrowth, sHA showed the lowest shear strength at both time periods. SEM after pushout test showed that sHA consistently demonstrated some regional failure at the HA-implant substrate interface. HA + Ti-spray had many failed regions either at the HA-bone interface or within the bone tissue rather than at the HA-implant substrate interface. These results suggested that the HA-coated smooth surfaced implants had a mechanical weakness at the HA-substrate interface. Therefore, HA should be coated on the rough surfaced implants to avoid a detachment of the HA-coating layer from the substrate and thus obtain a mechanical anchoring strength to bone. HA-coating on this new type of surface morphology may thus lead to a solution to the problems of conventional HA-coated and porous-coated implants.

Effects of ischemic preconditioning on ventricular arrhythmias during ischemia and reperfusion using a retrograde blood flow model in dogs

We examined the effects of ischemic preconditioning on ventricular arrhythmias during ischemia and reperfusion from the electrophysiologic point of view by using the retrograde blood flow (RBF) model, which causes severe ischemia. A total of 51 anesthetized dogs were divided into 3 groups. Group 1 (10-min simple occlusion) consisted of 15 dogs; group 2 (10-min RBF) consisted of 20 dogs; and group 3 (10-min RBF with preconditioning) consisted of 16 dogs. Preconditioning consisted of 5 cycles of 2 min of ischemia (RBF) and 5 min of reperfusion. In the subepicardium, myocardial blood flow (MBF) in group 2 was significantly lower than in group 1 or group 3 [group 2 (4.7 +/- 2.3 ml/min per 100 g) vs group 1 (35.0 +/- 5.8) or group 3 (22.0 +/- 4.6); p < 0.01 and p < 0.05 respectively]. However, there were no differences in MBF in the subendocardium between the 3 groups. The incidence of conduction block in the subepicardium was significantly higher in group 2 than in group 1 or group 3 [group 2 (85%) vs group 1 (33%), p < 0.01; vs group 3 (38%), p < 0.01]. There were no differences in the incidence of conduction block in the subendocardium between the 3 groups. During 10-min ischemia, the incidences of ventricular fibrillation (VF) were 7% in group 1, 35% in group 2, and 6% in group 3 (group 2 vs group 1, p < 0.05; and group 2 vs group 3, p < 0.05). During 10-min reperfusion, the incidences of VF were 29% in group 1, 77% in group 2, and 33% in group 3 (group 2 vs group 1, p < 0.05; and group 2 vs group 3, p < 0.05). Ventricular arrhythmias were reduced during both 10-min ischemia and 10-min reperfusion as a result of the improvement in the conduction components by ischemic preconditioning which increased MBF in the subepicardium.

Mouse deoxyribonuclease I (DNase I): biochemical and immunological characterization, cDNA structure and tissue distribution

Mouse urinary deoxyribonuclease I (DNase I) resembles rat and human DNase Is in terms of its proteochemical and enzymological properties. Furthermore, mouse DNase I was demonstrated to be immunologically closer to the rat than to the human enzyme. A 1176 bp full length cDNA encoding mouse DNase I was constructed from RNA obtained from the kidney and parotid glands. The amino acid sequence up to the 45th residue from the N-terminal of the mature enzyme was identical to that deduced from the cDNA sequence. This DNase I was distributed most densely in the parotid glands from the standpoint of both enzyme activity and gene transcript levels.

Application of glutaraldehyde-crosslinked chitosan as a scaffold for hepatocyte attachment

The effectiveness of chitosan, a biocompatible polymer derived by the deacetylation of chitin, as a scaffold of hepatocyte attachment, was examined. Since chitosan gel was too fragile to use for cell culture, its free amino groups were crosslinked by glutaraldehyde to increase its strength. Rat hepatocytes seeded onto glutaraldehyde-crosslinked chitosan (GA-chitosan) gel could stably attach to the surface, retaining its spherical form, the same as in vivo, and then release a very small amount of lactate dehydrogenase during the 5 d culture period. By contrast, hepatocytes on a collagen-coated surface spread flat, and they released much more lactate dehydrogenase than those on the GA-chitosan gel. Hepatocytes on GA-chitosan also retained higher urea synthesis activity, a liver-specific function, than those on the collagen-coated surface. These results indicate that chitosan is a promising biopolymer as a scaffold of hepatocyte attachment, which can be applied to an effective bioartificial liver support system.

Effects of nisoldipine on cytosolic calcium, platelet aggregation, and coagulation/fibrinolysis in patients with coronary artery disease

The effect of nisoldipine, a dihydropyridine Ca2+ antagonist, on the platelet cytosolic Ca2+ concentration ([Ca2+]i), platelet aggregation, and various coagulation and fibrinolysis parameters was assessed in normotensive patients with coronary artery disease (CAD). Eleven patients with angiographically confirmed CAD (4 men, 7 women aged 67.3 +/- 5.4 years) were administered nisoldipine at 10 mg/day for two weeks. The [Ca2+]i was determined by use of fura2-loaded platelets, platelet aggregation was measured with an aggregometer, and coagulation/fibrinolysis parameters were measured by standard methods. Nisoldipine did not significantly affect blood pressure or heart rate. However, the [Ca2+]i decreased significantly (P<0.05) and platelet aggregation was also significantly inhibited. Plasma D-dimer levels decreased significantly (P<0.01). Thus, nisoldipine not only suppressed platelet activation but also affected the coagulation system, suggesting that it is not only a vasodilator and platelet inhibitor but also an antithrombotic agent.

Comparative effects of dobutamine and amrinone on coronary blood flow in patients with idiopathic dilated cardiomyopathy

Although amrinone has favorable hemodynamic effects in patients with congestive heart failure, little is known about its effects on coronary blood flow (CBF). We compared the effects of intravenous low-dose dobutamine and amrinone on CBF in 10 patients with dilated cardiomyopathy using a Doppler guidewire. We infused dobutamine at a dose of 5 and 10 microg/kg/min for 5 min. After the end of each stage, coronary flow velocity (CFV) and coronary arterial diameter (CAD) in the proximal left anterior descending coronary artery, and hemodynamic variables were obtained. After the CFV and hemodynamics returned to baseline, we infused 1 mg/kg of amrinone over 5 min, and obtained these variables at 5 and 10 min after the cessation of the infusion. CAD did not increase with dobutamine, but significantly increased after amrinone (% increase: 10 +/- 7%; P < 0.001 vs. baseline). CFV progressively increased with dobutamine (5 microg/kg/min: 21 +/- 26%; P < 0.05 vs. baseline; 10 microg/kg/min: 53 +/- 42%; P < 0.005 vs. baseline and 5 microg/kg/min), but slightly decreased after amrinone (-4 +/- 17%; P = not significant vs. baseline). CBF increased during dobutamine (5 microg/kg/min: 25 +/- 29%; P < 0.05; 10 microg/kg/min: 66 +/- 55%; P < 0.005) and after amrinone (19 +/- 22%; P < 0.05) compared to that at baseline. Although there was a significant correlation between the percent increase in CFV and that in dP/dt during dobutamine infusion (r = 0.82, P < 0.001), this correlation was not observed after amrinone (r = 0.23). In conclusion, although both agents significantly increased CBF in patients with dilated cardiomyopathy, they do so by different mechanisms. Amrinone mainly increases CBF by causing dilatation of epicardial coronary arteries. These results suggest that amrinone has beneficial effects on coronary flow dynamics in dilated cardiomyopathy.

Binding of wild-type p53 by topoisomerase II and overexpression of topoisomerase II in human hepatocellular carcinoma

In order to study the mechanisms by which p53 function is regulated, human wild-type p53 cDNA was cloned into a vaccinia virus vector and the expressed p53 protein was used to investigate binding of the p53 by cellular proteins from a cDNA expression library from human liver. One protein that bound wild-type p53 had > 99% homology with DNA topoisomerase IIb. p53 protein was coimmunoprecipitated from topoisomerase II-rich cell lysates (but not from topoisomerase II-deficient cell lysates) by an antibody to topoisomerase IIa and IIb. This binding was shown to occur without a dsDNA intermediary. Hepatocellular carcinomas (HCCs) and adjacent nontumorous liver tissues from ten patients were studied to determine the level of expression of topoisomerase II and p53. Overexpressed topoisomerase II proteins were detected by western blot in six of ten HCCs (60%), including several in which presumed wild-type p53 was detected by immunohistochemistry. No topoisomerase II expression was detectable in the ten nontumorous liver tissues from the same patients or in a sample of normal human liver.

[Progression of renal disease in patients with reflux nephropathy. Follow-up study]

BACKGROUND

We previously estimated the turning point of reflux nephropathy irreversibly deteriorating to end stage renal disease, mainly based on findings in renal biopsy (Eur. Urol., 26: 153-159, 1994). In this study, we aim to evaluate clinical parameters which may be closely associated with progression of reflux nephropathy to end stage renal disease.

SUBJECTS AND METHODS

Ninety five patients (84 children and 11 adults; 41 men and 54 women) with renal scar and/or reflux (>/ = grade 3), mean aged 9.4 +/- 9.1 years (3 months-53 years) were followed up for 3.7 years +/- 2.7 (6 months-18 years). Vesicoureteral reflux was bilateral in 64 and unilateral in 31; primary in 85 and secondary in 10 patients. Clinical parameters including body weight, height, blood pressure, 24 hour urinary protein excretion, serum creatinine, 99m Tc-DTPA GFR and 99 m Tc-DMSA uptake were monitored over time. All patients underwent antireflux surgery (with or without other reconstructive surgery) and open renal biopsy. Three patients progressing to end stage renal disease underwent subsequent biopsy.

RESULTS

Over-5 year observation period, the prevalence of new scare formation and further extension in scar was significantly higher in the group of renal functional deterioration (35%) than in the group of stable renal function (6.0%). Over the same period DMSA uptake decreased significantly (< 0.05) in the group of scar b (Smellie's classification), suggesting most kidneys of scar b eventually resulting in atrophic kidney (scar c). Proteinuria more than 100 mg/day appeared to be a critical level for predicting irreversible deterioration in renal function. Glomerular hypertrophy was closely related to the increase in urinary protein excretion and serum creatinine, contrary to the decrease in DTPA-GFR. In addition, bilateral renal scar b, glomerular hypertrophy (> 2 SD), proteinuria (> 300 mg/day), low GFR (mean: 49 ml/min), and diastolic hypertension seemed to be implicated in the genesis of ESRD.

CONCLUSION

Glomerular damage due to either reflux nephropathy or dysplasia may cause proteinuria. Proteinuria of 100 mg/day was significantly (p < 0.01) associated with 2 SD of glomerular hypertrophy on histology and clinical observation (suggesting hyperfiltration). Thereafter, a rapid increase in proteinuria followed by diastolic hypertension appears be significant for predicting ESRD.

Effects of an angiotensin II antagonist on reperfusion arrhythmias in dogs

Losartan, an angiotensin II receptor antagonist with no bradykinin potentiating property, provides the opportunity to study the consequences of blocking angiotensin II. The objective of this study was to evaluate the antiarrhythmic responses of reperfusion arrhythmia to losartan in dogs. The effects of losartan on ventricular tachyarrhythmias induced during occlusion and reperfusion of the left anterior descending coronary artery were investigated in 30 dogs. The animals were randomized to receive either losartan (n = 15) or saline (n = 15). The VF inducing threshold was measured before occlusion and after reperfusion. Losartan (50 micrograms/kg per min) or saline was intravenously administered 5 minutes before occlusion and continued throughout the entire study period. The incidence of ventricular tachyarrhythmias during reperfusion was lower in the losartan group than in the control group (4/15 vs 6/15). There was no significant change in VF inducing threshold between the period before occlusion and during reperfusion in the losartan group [10.9 +/- 5.7 vs 11.1 +/- 5.7 mA, P = NS), whereas there was a significant decrease in the control group (15.5 +/- 4.4 vs 7.7 +/- 3.9 mA, P < 0.01). Blockade of the angiotensin II receptor has beneficial effects on reperfusion arrhythmias.

Effects of lidocaine and diltiazem on recovery of electrophysiologic activity during partial reperfusion following severe myocardial ischemia in canine hearts

The effects of lidocaine and diltiazem on recovery of electrophysiologic activity during partial reperfusion following severe myocardial ischemia were investigated in 28 dogs. The left anterior descending artery was ligated, and the distal end was connected to the carotid artery. Myocardial ischemia was induced by retrograde blood flow for 10 minutes, after which flow-limited reperfusion (30-60% of the coronary flow before ischemia) was performed. The dogs were divided according to the agent administered before ischemia into the following three groups: saline (group S, n = 11); lidocaine (group L, n = 8, 0.07 mg/kg/min by intravenous drip infusion following 2 mg/kg intravenous injection); and diltiazem (group D, n = 9, 0.02 mg/kg/min by intravenous drip infusion. There were no significant differences among the three groups in the incidence of ventricular tachyarrhythmia, which occurred as ventricular tachycardia (VT) or ventricular fibrillation (VF). In each group, the occurrence of VT was frequently preceded by delayed potential which was initiated after reperfusion, with depressed conduction in the epicardium, suggesting reentry (82%, 96%, and 87%, not significant). The determining factors for VT with degeneration into VF were long duration of VT in groups S and L (VT with degeneration into VF vs VT without, 1.2 +/- 0.2 seconds vs 0.6 +/- 0.1 seconds, P < .05, in group S and 11.6 +/- 2.5 seconds vs 2.2 +/- 0.4 seconds, P < .05, in group L), and decrease in average R-R interval during VT in groups L and D (195 +/- 8 ms vs 313 +/- 17 ms, P< .01, in group L and 201 +/- 11 ms vs 327 +/- 28 ms, P< 0.01, in group D). In addition, occurrence of epicardial electrophysiologic activity with reduced time from onset of the QRS complex in the surface electrocardiogram to the onset of the activity during VT preceded VF in group L (VT with degeneration into VF vs VT without, 130.0 +/- 15.1 ms vs 185.8 +/- 21.4 ms, P < .05), while that with prolongation of the time had this effect in group D (116.0 +/- 15.7 ms vs 69.0 +/- 10.7 ms, P < .05). It is concluded that, even when partial reperfusion is applied, neither lidocaine nor diltiazem suppresses VT because neither drug decreases delayed potential acting as a triggering factor or suppresses VF, since the alteration of the epicardial conductivity during VT can change the VT circuit to a smaller one.

Hexachlorobenzene accumulated by dams during pregnancy is transferred to suckling rats during early lactation

The distribution of ingested stable, lipophilic environmental pollutants in dams and their transfer to fetuses and sucklings were investigated in rats fed a diet containing a small amount (35.1 nmol/100 g diet) of hexachlorobenzene (HCB). In the first experiment, we examined the distribution of HCB in pregnant and nursing rats fed the HCB diet during pregnancy and lactation. Its transfer to their sucklings was also studied. On d 16 after parturition, HCB concentrations in the blood, and subcutaneous and perirenal fat of nursing rats fed the HCB diet during pregnancy and lactation were approximately 1/3.5, 1/15 and 1/2.8, respectively, those of pregnant rats fed the HCB diet only during pregnancy. On the other hand, the HCB concentrations in the blood, and subcutaneous and perirenal fat of sucklings were approximately 6, 29 and 15 times higher than those of their dams. Therefore, a large amount of HCB apparently was transferred from dams to suckling pups through the milk. In the second experiment, we fed dams the HCB diet only during pregnancy and determined the distribution of HCB in the pregnant rats and fetuses as well as in the nursing rats and suckling pups. The estimated amount of HCB transferred from a dam to her fetuses corresponded to about 0.39% of her total intake during pregnancy. The amount of HCB detected in nursing rats on d 16 after parturition was much smaller than that in the pregnant rats, suggesting that a large proportion of the HCB that accumulated during pregnancy disappeared from the organs and fat tissues during lactation. The HCB concentration in the stomach contents of suckling pups fed by the dams who had consumed HCB before parturition was highest on d 2 after birth and decreased gradually during the 16 d after birth. In the blood, liver and fat tissues of suckling rats, the HCB concentrations increased until 7 d after birth and then decreased gradually. We conclude that the HCB that accumulated in dams during pregnancy was transferred to their suckling pups through milk in the early days after birth.

Effect of aortic valve replacement on coronary flow velocity during metabolic stress in a patient with aortic stenosis

The effect of aortic valve replacement on coronary flow velocity during atrial pacing and papaverine-induced-resistance vessel dilatation was tested in a patient with aortic stenosis. Although systolic flow reversal disappeared early after the valve replacement, rapid atrial pacing caused myocardial ischemia with lactate production. The coronary flow reserve also remained depressed. These results suggest that the alteration in the coronary flow profile early after the aortic valve replacement does not reflect an improvement in the flow increase during metabolic stress in a patient with aortic stenosis.