Fetal cardiac morphology of tetralogy of Fallot with absent pulmonary valve in the rat

Fetal in situ cardiovascular and bronchial morphologies were studied in rats with tetralogy of Fallot and absent pulmonary valve to clarify the prenatal pathology of this complex. There were 42 fetal rats with this complex among 300 fetuses treated with N,N'-bis-(dichloroacetyl)-1,8-octamethylenediamine (bis-diamine) (200 mg) on the 10th day of pregnancy. After undergoing rapid whole-body freezing on the 21st day, they were studied by means of serial cross-sectional photographs of the frozen thorax. Fetuses with normal heart treated with bis-diamine served as control. Tetralogy of Fallot and absent pulmonary valve in the fetus was associated with absence of the ductus arteriosus, enlargement and hypertrophy of both ventricles, and enlargement of the pulmonary arteries that compressed the bronchial trees. These abnormalities were inversely correlated with the degree of pulmonary stenosis. Milder stenosis (pulmonary valve ring greater than 50% of control, n = 28) was associated with larger pulmonary arteries (250 +/- 12% of control) (mean +/- SEM) and larger ventricles (volume, 200 +/- 15%; mass, 130 +/- 4%). Severe stenosis (pulmonary valve ring less than 50% of control, n = 14) was associated with mildly enlarged pulmonary arteries and mild bronchial compression. We concluded that enlargement of the pulmonary arteries and bronchial compression develop in fetal life and are associated with mild pulmonary stenosis in tetralogy of Fallot and absent pulmonary valve.     

Alterations in stress distribution patterns through the forearm joint surface of the elbow in baseball players assessed using computed tomography osteoabsorptiometry

Background

The distribution of subchondral bone density well reflects long-term resultant stress acting on an articular surface in living joints. Consequently, a measurement of the distribution pattern can determine the stress distribution across the elbow joint surface under long-term loading conditions of baseball pitching. Our purpose was to elucidate the characteristic alterations in the distribution pattern of subchondral bone density across the forearm bones of the elbow with pitching activities. The hypothesis is that pitching activities would change the stress distribution in living subjects.

Methods

The analysis was performed using computed tomography (CT) images obtained from the dominant elbow of ten nonthrowing athletes (control group), ten college baseball fielders (fielder group), and ten college baseball pitchers (pitcher group). The distribution pattern of subchondral bone density through the articular surface of the proximal radius and ulna bones was assessed using CT osteoabsorptiometry.

Results

The maximum density area was located in the posterior part of the trochlea notch in all study participants. This maximum density area was significantly increased in the baseball groups compared with that in the control group. The pitcher group also showed a significant distribution of the maximum density area in the anterior part of the radial head.

Conclusion

Our analysis indicates that pitching activities increase actual stress on the articular surface not only in the posterior part of the trochlea notch but also in the anterior part of the radial head. The stress across the elbow may be expanded from the ulnohumeral to the radiohumeral joint by repetitive pitching activities in living subjects.     

A method for identifying causative chemicals of allergic contact dermatitis using a combination of chemical analysis and patch testing in patients and animal groups: application to a case of rubber boot dermatitis

A 63-year-old woman developed allergic contact dermatitis from rubber boots. Initial investigation, by patch testing in the patient and chemical analysis of the causative rubber boots, revealed that mercaptobenzothiazole (MBT) and dibenzothiazyl disulfide (MBTS) were the causative chemicals. Subsequent investigations were performed by patch testing in animal groups. An extract of the causative rubber boots, MBT and MBTS were used for sensitization of guinea pigs by the guinea pig maximization test (GPMT). 3 animal groups, A (with the boot extract), B (with MBT) and C (with MBTS) were successfully prepared. The boot extract was fractionated by column chromatography and thin-layer chromatography (TLC). Each fraction was subjected to patch testing in the animal groups. Positive reactions in all groups would show that the active fractions contained MBT-type compounds, whereas a positive reaction in group A but negative ones in group B and C would show that the active fractions did not contain any MBT-type compounds. Each fraction was then analyzed by gas chromatography (GC), GC-mass spectrometry (GC-MS), direct inlet-MS (DI-MS) and high-performance liquid chromatography (HPLC). By this investigation, we found not only known allergens (MBT, MBTS), but also unknown allergens: S-substituted MBT-type compounds and styrenated phenol (SP). Thus, SP was shown to be a candidate as a human sensitizer even though the patient did not react to it.     

Comparison of intraoperative ultrasound with postimplant computed tomography--dosimetric values at Day 1 and Day 30 after prostate brachytherapy

PurposeTo compare the results of intraoperative dosimetry with those of postimplant computed tomography (CT)-based dosimetry after ¹²⁵I prostate brachytherapy.Methods and materialsWe treated 412 prostate cancer patients with ¹²⁵I prostate brachytherapy, with or without external beam radiotherapy at our institution. Neoadjuvant hormone therapy was administered to 331 patients (80.3%). Implantation was performed using an intraoperative interactive technique. Postimplant dosimetry was performed on Day 1 and Day 30 using CT imaging. The dosimetric results for the prostate, urethra, and rectum were compared among intraoperative ultrasound, and CT scans of Day 1 and Day 30.ResultsThe mean intraoperative minimal dose received by 90% of the prostate volume (D₉₀) was 118.8% of the prescribed dose vs. 106.4% for Day 1 (p < 0.01) and 119.2% for Day 30 (p = 0.25). There were no significant correlations between the intraoperative D₉₀ and the postimplant D₉₀ values (intraclass correlation coefficients = 0.42 and 0.33 for Day 1 and Day 30, respectively). Prostatic edema at Day 1 had the largest effect on the Day 1 D₉₀ (p < 0.01). The factor significantly affecting the Day 30 D₉₀ was neoadjuvant hormone therapy (p < 0.01). The mean Day 30 D₉₀ for the hormone-treated patients was 117.9%, compared with 124.6% for those who remained hormone naïve. The intraoperative and postimplant dosimetric values differed significantly for the urethra and rectum.ConclusionsOur results demonstrate that there are no significant differences between the D₉₀ assessments obtained intraoperatively and at Day 30 postoperatively. Furthermore, there are no definite correlations between intra- and postimplantation dosimetric values. Other D₉₀ values differed significantly between the intraoperative and postimplant dosimetry. This study suggests that dosimetry has negligible clinical utility for informing patients, at discharge, of whether or not their implants are adequate.     

Myocardial dysfunction and depressed fatty acid metabolism in patients with cyanotic congenital heart disease

Background

Myocardial contractile dysfunction has been frequently observed in adolescents or adults with cyanotic congenital heart disease. Impaired energy metabolism may be present in such dysfunctional myocardium.

Methods and Results

To evaluate the findings of myocardial free fatty acid metabolism, and its relations to ventricular wall motion and myocardial perfusion in cyanotic congenital heart disease, we performed a combined study of iodine 123-labeled 15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) scintigraphy, thallium scintigraphy, and contrast cineangiography in seven patients with single right or left ventricle. The results showed that wall motion was reduced in 17 of 35 ventricular segments (49%), which were mostly identical in location to decreased BMIPP uptake. The severity of BMIPP uptake deficit correlated positively with the degree of impairment of wall motion. On the other hand, thallium uptake was abnormal only in 5 of 35 segments (14%), and the severity of the perfusion defect did not correlate with the degree of wall motion abnormality.

Conclusions

Contractile dysfunction in cyanotic heart disease was primarily linked to impaired free fatty acid metabolism rather than to myocardial scar as represented by perfusion defect on thallium imaging.     

HCO3(-)-dependent intracellular pH regulation in the premature myocardium.

This study investigated developmental changes in Na(+)-H+ exchange and HCO3(-)-Cl- exchange activities in newborn and adult rabbit hearts. pHi was measured using the fluorescent dye 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein in isolated myocytes. Myocardial mechanical function was measured in the isolated ventricular preparation. Intracellular acidosis with normal pHo was induced by an NH4Cl (10 mM) prepulse technique. Upon removal of NH4Cl, pHi fell transiently and then recovered toward the control level. In the HCO3-/CO2-buffered solution, the rate of recovery of pHi in the newborn was greater than in the adult. In the HCO3-/CO2-buffered solution, 5-(N-ethyl-N-isopropyl)amiloride (EIPA), an inhibitor of Na(+)-H+ exchange, inhibited the recovery of pHi completely in the adult. In the newborn, however, significant recovery of pHi was observed in the presence of EIPA. In the presence of both EIPA and 4-acetamido-4'-isothiocyanatostilbene-2',2'-disulfonic acid (SITS), an inhibitor of HCO3(-)-Cl- exchange, the recovery of pHi was not observed in the two age groups. In the HEPES-buffered solution that did not contain HCO3-/CO2, the rate of recovery of pHi after NH4Cl removal was similar in the two age groups. In the HEPES-buffered solution, the recovery of pHi was completely inhibited by EIPA in the two age groups. In the presence of EIPA in the HCO3-/CO2-buffered solution, contractile function decreased during acidosis after NH4Cl removal and did not recover in the adult. In the newborn, significant recovery of contractile function was observed after NH4Cl removal in the presence of EIPA. The recovery of mechanical function observed in the presence of EIPA in the newborn was inhibited by SITS. These data suggest that, although there is no developmental change in the Na(+)-H+ exchange activity, HCO3(-)-Cl- exchange is more active in the premature myocardium. The presence of the HCO3(-)-Cl- exchanger is important in maintaining myocardial contractile function during acidosis, especially when Na(+)-H+ exchange is inhibited and may partly explain the greater resistance of the premature myocardium to acidosis.     

Pulmonary arteriography through patent ductus arteriosus with preformed catheters

Selective pulmonary arteriography was performed successfully with new preformed catheters in eight consecutive patients with pulmonary atresia or severe stenosis and patent ductus arteriosus. The catheters were inserted percutaneously into the femoral artery and passed into the patent ductus arteriosus very easily within a few minutes. Pulmonary arteriography was performed with biplane cineangiography. All eight patients showed either stenosis or secondary atresia in the central pulmonary artery. The obstructive lesions occurred at the junction of either a patent ductus arteriosus or a surgically anastomosed subclavian artery.