Capillary basal laminar thichness in diabetic human myocardium.

Biopsied myocardial tissue was obtained from 24 patients electing coronary arterial bypass surgery who were divided into three groups: chemical diabetics (CD) with normal fasting blood sugar levels and incidentally encountered elevated glucose levels after sugar loading; overt diabetics (OD) requiring insulin treatment; and euglycemic, nondiabetic patients (ND) serving as a control group. Specimens from the left anterior apical segment of the heart were processed for ultrastructural examination, with special emphasis on determining capillary basal laminar thickness with the aid of morphometric techniques. Results of this study indicate that (1) a statistically significant increase in basal laminar thickness is evident in myocardial tissue of OD patients; (2) incipient alterations in laminar width are demonstrable in the CD group; (3) the predominant morphologic abnormalities, which we have examined in the parenchymal tissue of the biopsied hearts, namely myocardial hypertrophy and interstitial fibrosis, are present to a comparable degree in all three groups of patients; and (4) the average thickness of basal laminae around myocardial capillaries tends to be narrower compared with measurements reported in other tissue compartments.     

配色粘接剂改善瓷贴面修复ND6-ND9颜色效果的初步研究

目的:应用配色粘接剂色料含量-色度值回归方程,定量计算配制个体化的配色粘接剂,研究个体化配色粘接剂对改善锂基瓷贴面修复ND6-ND9背景色的色彩效果。方法:选取IPS natural die material基牙比色板ND6、ND7、ND8、ND9各6片,共24片做为比色试件的基底;制备Ips.e.max A2 HT厚度为0.7mm试件24片。分别采用透明粘接剂和配色粘接剂将试件与基底粘接,制备透明组与配色组试件。用Crystaleye分光光度计比色仪测量试件的色度值,计算各组色度值与A2比色板色度值之间的色差值,并进行统计学分析。结果:配色组与目标色A2间色差值﹙△E﹚较透明组与目标色A2间色差值﹙△E﹚明显减小。秩和检验比较两者间差异有统计学意义﹙P<0.05﹚。结论:应用色料含量-色度值回归方程制作的配色粘接剂,可以改善锂基瓷贴面修复ND6-ND9背景色的美观效果。     

Diagnosis of hypoplasia of the heart ventricles: role of morphometry and morphology in its assessment

The article deals with the results of the study of the quantitative anatomy and morphology of hypoplastic ventricles. The object of study were 28 specimens of the heart: 15 with hypoplasia of the left ventricle and 13 with hypoplasia of the right ventricle. The control group was composed of 10 specimens of normal hearts. Morphometry was conducted in all of the 28 specimens. At the same time angiocardiometry and calculations of the volume characteristics of the ventricles were undertaken in the diagnosis of hypoplasia of the right ventricle. The morphometric criteria of hypoplasia of the heart ventricles and their morphological variants were determined as a result. It was found that the lineal characteristics of the heart yielded sufficient information both for the diagnosis of hypoplasia and for determining its degree. Morphometry showed that constant ratios exist between the diameters of the atrioventricular valves and the lineal sizes of the ventricles in normal and pathological hearts. Knowledge of the aforesaid is of much practical importance because having determined the sizes of the atrioventricular valves during echocardiography one may calculate all linear characteristics of the heart and evaluate the sizes of the ventricles by means of the quantitative criteria. The article gives the method of such calculation, while its results are evidence of the high precision of the suggested constants.     

Correlation of hormone levels and quantitative histological findings in testicular biopsies

Testicular biopsies of 84 oligo- or azoospermic males with gonades of nearly normal size and without chromosomal abnormalities were studied by morphometric methods. The mean Johnsen score and the results of the morphometric investigations were plotted against the results of the hormone assays (plasma testosterone, LH, FSH, prolactin). High LH and FSH levels showed a very good correlation with the loss of germ cells, the tubular shrinkage and interstitial fibrosis. Plasma testosterone levels, however, did not correlate with any morphological structure of the testicular parenchyma. The Johnsen score and the morphometric findings can to some degree explain the relationship between morphological abnormalities and endocrinological findings.     

Short-term reproducibility of cystometry and pressure-flow micturition studies in healthy women

AIMS: To evaluate the reproducibility of cystometry and pressure flow studies in women. We wanted to explore any clinically relevant effect of repeated, same-session cystometry. METHODS: Thirty healthy women with a mean age of 52 years were investigated with repeat medium-fill water cystometry and pressure-flow micturition studies in a single session. RESULTS: Large test-retest variability was noted, with wide limits of agreement. Of statistical significance was an increase of first desire (FD) and normal desire (ND), and a decrease in bladder opening pressure. Maximum cystometric capacity was unchanged. CONCLUSIONS: Although the nature of the conditioning effect of the first fill remains to be explored, the phenomenon could possibly be used for improved urodynamic diagnosis.     

Coronary arterial and sinusal anatomy in hearts with a common arterial trunk

Eighty-four specimens of common arterial trunk were studied with special reference to the arrangement of the leaflets in relation to the atrioventricular valves, the origin of the coronary arteries in relation to the arterial sinuses, and the epicardial course of the coronary arteries. Fourteen normal hearts were used for comparison. In the hearts with common arterial trunk, the location and level of the coronary artery orifices (as well as the relationship of the truncal root to the area of fibrous continuity with the mitral valve) are different from those in normal hearts. In none of the hearts with common arterial trunk (particularly the 53 hearts with three leaflets in the truncal valve) did the appearance of the truncal valve approximate that of a normal aortic valve. Among the 22 hearts with four leaflets, there was a high incidence of coronary artery orifices in opposite sinuses (17/22 or 77.3%) and a low incidence of coronary artery orifices in adjacent sinuses (2/22 or 9.1%). These results suggest that the formation of the truncal valve is independent of the formation of the coronary orifices. Its leaflets are not predestined to become part of either the aortic valve or the pulmonary valve.     

Myocardial energy metabolism in asphyxiated canine hearts preserved for 24 hours.

Myocardial energy metabolism in asphyxiated cadaver hearts preserved in UW solution (UWS; group 1, n = 6) or modified Collins' solution (MCS; group 2, n = 6) was compared with that in cardioplegic arrested hearts immersed in ice-cold MCS with (group 3, n = 6) or without myoprotective drugs (group 4, n = 5). All hearts were stored for 24 hr. The hearts in groups 1 and 2 were pretreated with prostacyclin, verapamil, and propranolol; asphyxiated for 10 min, reversed by coronary perfusion with warm blood cardioplegia (WBCP); perfused with ice-cold crystalloid cardioplegia for 2 hr; excised and immersed in cold storage solution for 22 hr; and perfused again with WBCP before reperfusion. ATP contents were measured in biopsy specimens by HPLC. Myocardial ATP level decreased significantly from 23.7 +/- 1.7 to 15.9 +/- 2.5 mumol/g dry wt. (P less than 0.0001) by asphyxia, but recovered to within normal limits by WBCP in group 1. The ATP level again decreased to 15.8 +/- 2.4 mumol/g dry wt. during 24-hr storage, but finally rose to 22.4 +/- 3.5 mumol/g dry wt. by terminal WBCP. The ATP metabolism in group 2 was similar to that in group 1. The ATP content in group 4 was significantly lower than that in other groups (P less than 0.01) after 24-hr preservation. The study shows that damage to cadaver hearts can be reversed and the hearts maintained satisfactorily viable for 24 hr.     

Serial morphological changes in primate skeletal myofibres after 3 hours of ischaemia and 24 hours of reperfusion.

The sequential morphological changes occurring in skeletal myofibres after 3 hours' ischaemia and from 3 hours to 24 hours of reperfusion in vervet monkeys are described. Eight vervet monkeys were studied under general anaesthesia. A hind limb was exsanguinated and a tourniquet applied for 3 hours. Open muscle biopsy specimens were obtained from the tibialis anterior muscle before tourniquet application, just before tourniquet release and 3, 6, 12, 18 and 24 hours after tourniquet deflation. All specimens were prepared for transmission electron microscopy. After 3 hours of ischaemia and increasing periods of reperfusion, a small number of fibres showed progressive pathomorphological changes that eventually resulted in myofibre death. After initial glycogen loss and later intermyofibrillar oedema, the majority of myofibres returned to normal, while a group of fibres remained oedematous. The progressive morphological characteristics of reversibly injured myofibres undergoing repair and irreversible injured cells undergoing necrosis are described.     

Analysis of solid renal dysplasia by flow cytometry: malignant potential?

Renal nodular blastema/nephroblastomatosis is a recognized precursor of Wilms tumor. It also has been shown that nodular renal blastemata are seen in association with dysplastic renal parenchyma secondary to obstructive uropathy (i.e., ureteroceles or ectopic ureters). In an attempt to improve our understanding of the critical relationship between renal dysplasia and neoplasia, we performed flow cytometric evaluation on 16 paraffinembedded specimens of dysplastic kidneys removed during the period 1984–1989. All nephrectomy specimens were associated with obstruction, either duplex collecting systems (10), ectopic ureters (2) or posterior urethral valves (2), or vesicoureteral reflux (2). One specimen was found to contain nodular renal blastema. No evidence of malignancy was found in any specimen. A specimen of normal kidney and two of Wilms tumor (favorable histology) were studied for comparison. Nuclear deoxyribonucleic acid (DNA) ploidy studies were performed on single dissociated nuclei after deparaffinization and staining with propidium iodide. All dysplastic specimens, including the specimen with nodular renal blastema, demonstrated a diploid pattern of DNA as did the specimens of normal renal tissue. The Wilms tumor specimens demonstrated a diploid and a tetraploid pattern. In view of the fact that Wilms tumor may demonstrate diploid DNA patterns on flow cytometry, the findings of diploid patterns on all specimens of solid dysplasia militate against but do not eliminate the possibility of malignant degeneration.     

Morphology of the ventriculoaortic junction in critical aortic stenosis. Implications for hemodynamic function and clinical management.

The clinical presentation of infants with critical aortic stenosis, as well as the results of surgical treatment, differs from obstruction of the left ventricular outflow tract in older children. To investigate a possible anatomic basis for this situation, we performed a detailed morphometric study of 21 hearts from infants who had critical aortic stenosis and 11 normal hearts from infants less than 3 months of age. In each of the hearts with critical aortic stenosis, only one commissure extended to the sinutubular ridge. The other two commissures were represented by folds in the aortic wall that suspended the leaflet below the level of the sinutubular junction. The leaflet thus had a free edge shorter than the circumference of the sinus, in contrast with the normal valve, in which leaflets always were longer than the circumference of their supporting sinus. Analysis of the fibrous triangles on the ventricular aspect of abnormal valves showed a symmetric three-sinus arrangement. In all but one specimen, however, only the triangle related to the mitral valve was fully developed. Although incision of both rudimentary commissures to the aortic wall should achieve some relief of obstruction, these morphologic features strongly mitigate against surgical restoration of normal function or growth in aortic valves having the morphology observed in this series of hearts.     

Theramal, mechanical, optical, and morphologic changes in bovine nucleus pulposus induced by Nd:YAG (lambda = 1.32 microm) laser irradiation

BACKGROUND AND OBJECTIVE To examine the biophysical effects of photothermal heating on herniated intervertebral discs during laser decompression surgery. STUDY DESIGN/MATERIALS AND METHODS: Ex vivo bovine nucleus pulposus specimens were irradiated with a Nd: YAG laser (lambda = 1.32 microm, 100 seconds exposure time, 9-31 W/cm(2), 4.8 mm spot diameter), whereas changes in tissue thermal, mechanical, and optical properties were monitored by using, respectively, infrared radiometry, tissue tension measurements, and diffuse reflectance from a HeNe probe laser. Morphologic changes and mass reduction were monitored by recording shape changes on video and weighing specimens before and after laser exposure. RESULTS: At power densities below 20 W/cm(2), evaporation of water and specimen volume reduction (shrinking) were consistently observed on video during irradiation. In contrast, above 20 W/cm(2), vapor bubbles formed within the specimen matrix and subsequently ruptured (releasing heated vapors). When radiometric surface temperature approaches approximately 60 to 70 degrees C (denaturation threshold for tissue), tissue tension begins to increase, which is consistent with observations of specimen length reduction. The onset of this change in tissue tension is also reflected in characteristic alterations in diffuse reflectance. With cessation of laser irradiation, a sustained increase in tissue tension is observed, which is consistent with changes in specimen length and volume. Higher laser power results in a faster heating rate and subsequently an accelerated tension change. Specimen mass reduction increased with irradiance from 19 to 72% of the initial mass for 9--31 W/cm(2), respectively. Irradiated specimens did not return to their original shape after immersion in saline (48 hours) in contrast to air-dried specimens (24 hours), which returned to their original shape and size. CONCLUSION: These observations suggest that photothermal heating results in irreversible matrix alteration causing shape change and volume reduction (observed on video and evidenced by the increase in tissue tension) taking place at approximately 65 degrees C. Inasmuch as high laser power results in vapor bubble formation and specimen tearing, the heating process must be controlled. Diffuse reflectance measurements provide a noncontact, highly sensitive means to monitor dynamically changes in tension of nucleus purposus.     

Tissue strength analysis of autologous and cadaveric allografts for the pubovaginal sling.

The aim of this study was to compare the mechanical properties of autologous rectus fascia (ARF), two groups of commercially available cadaveric fascia lata commonly used in pubovaginal sling surgery [freeze-dried (FD) and solvent-dehydrated (SD)], and commercially available cadaveric dermal grafts (DG) evaluate differences in tissue strength and stiffness. We prospectively studied the maximum load to failure (MLF) and stiffness in 20 specimens of ARF, 20 specimens of FD, 20 specimens of SD, and 10 specimens of DG. Autologous fascia was obtained from patients undergoing pubovaginal sling operation utilizing rectus fascia. Cadaveric fascia was re-hydrated in saline. All specimens were then tailored into 1 x 1-cm samples and mounted onto the Instron tensiometer. Samples were loaded to failure at a 100% strain rate and force-elongation curves were generated. MLF was defined as the minimum force needed to tear the tissue. Stiffness was determined by the slope of the linear portion of the force/elongation curve between 5 and 15% strain. Statistical analysis was performed using Student's t-test. There is no statistical difference in both MLF and stiffness among ARF, SD, and DG. These data show that MLF and tissue stiffness of SD and DG are comparable to that of ARF. FD has a significantly lower MLF and is significantly less stiff than ARF, SD, and DG. The SD cadaveric fascia lata allograft and the cadaveric dermal allograft may be suitable alternatives to ARF for pubovaginal sling surgery. Neurourol. Urodynam. 18:497-503, 1999.     

Intraoperative outflow resistance as a predictor of late patency of femoropopliteal and infrapopliteal arterial bypasses

To evaluate the efficacy of intraoperative outflow resistance (OR) measurements in predicting late graft patency rates (PR) for femoropopliteal (FP) and femoroinfrapopliteal (FD) bypasses, we have reviewed 134 such cases performed during the past 3 years at our institution. Of these, 64 bypasses were FP (13 autogenous saphenous vein [ASV] and 51 polytetrafluoroethylene [PTFE]) and 70 were FD (43 ASV and 27 PTFE). Total and distal OR measurements (measured in millimeters of mercury per milliliter per minute) were divided into four groups each for all infrainguinal bypasses combined and for FP and FD bypasses separately. The relationship of PR to total and distal OR measurements were analyzed according to the product limit method. Overall 1- and 2-year PRs were 64% and 56%, respectively. For FP bypasses the same PRs were 78% and 67% whereas for FD bypasses, they were 52% and 45%, respectively. The 1-year PRs for FP and FD bypasses within each respective OR group were analyzed. For FP bypasses in the lowest to the highest total OR groups, the 1-year PRs were 86%, 75%, 78%, and 62% (NS), and for FD bypasses they were 72%, 89%, 23%, and 22% (p less than 0.001). Similar trends were observed when distal OR measurements were analyzed. For infrainguinal PTFE bypasses, both total and distal OR measurements were significant predictors of patency, whereas for those with ASV only distal OR measurements were predictive. These data reaffirm our early experience with OR measurements. Although a trend for predicting graft patency was noted for FP bypasses, OR measurements were highly predictive only for FD bypasses.     

Glomerular basement membrane thickness in primary diffuse IgA nephropathy: Ultrastructural morphometric analysis

Sixteen renal biopsy specimens from adult patients with IgA nephropathy (IgAN) for whom both light and electron microscopy as well as immunofluorescence microscopy and full clinical data were available were examined quantitatively and compared with six cases of normal controls. The electron micrographs of the glomeruli were scanned in a Primax flatbed A4 scanner and then morphometric investigations were performed by means of a computer image analysis system to evaluated glomerular basement membrane (GBM) thickness and to study whether this parameter could correlate with the degree of the haematuria, which is thought to be a main renal symptom in this glomerulopathy. The study revealed that the mean value of the GBM thickness was in IgAN patients significantly lower in comparison with normal controls (268.6 nm versus 338.8 nm). The authors also noted the tendency to negative correlation between GBM thinning and haematuria, although this relationship was not significant. It is suggested that deposits located in the vicinity of the capillary loops may play a role in this process.     

Effects of nucleoside transport inhibition on long-term ex vivo preservation of canine hearts.

The effect of nucleoside transport inhibition on 24-hour preservation of canine hearts was studied in 36 hearts arrested either with a cold hyperkalemic cardioplegic solution without (group I) or with supplementation of a specific nucleoside transport inhibitor (R75231, 1 mg/L) (groups II and III). The hearts were excised and stored for 24 hours at 0.5 degrees C. Then they were reperfused for 3 hours with use of a closed perfusion system primed with normal blood (groups I and II) or with blood supplemented with the same nucleoside transport inhibitor (0.32 mg/L) (group III). Serial biopsy specimens for determination of myocardial purines were taken. Creatine kinase and heat-stable lactate dehydrogenase release from the myocardium were examined during reperfusion. Recovery of function was studied during reperfusion by measurement of isometric contraction in a fluid-filled intraventricular balloon. After 24 hours of preservation, without the use of the drug, myocardial inosine and hypoxanthine accumulated to, respectively, 4.05 +/- 1.18 and 0.28 +/- 0.08 mumol/gm dry weight. In the drug-treated groups (II and III pooled), significantly less inosine and hypoxanthine accumulated (1.68 +/- 0.33 and 0.05 +/- 0.02 mumol/gm dry weight, respectively) (p < 0.05 versus group I). Upon reperfusion, intramyocardial adenosine was lost in the control hearts and maintained in the drug-treated hearts. Hypoxanthine accumulated significantly (p < 0.05) during reperfusion in group I (1.08 +/- 0.43 versus 0.16 +/- 0.13 in group II and 0.03 +/- 0.03 mumol/gm dry weight in group III). The rate of creatine kinase and heat-stable lactate dehydrogenase release was significantly lower (p < 0.05) in group III (that is, pretreatment and posttreatment with the drug) than in the control group. Functional recovery of hearts in group III was superior to that in group II (p < 0.05), while hearts in group I showed no recovery at all. We conclude that nucleoside transport inhibition improves long-term preservation of the heart and that the mechanism of this protection may be related to an increase in endogenous adenosine and reduction of myocardial hypoxanthine content.     

Sequential dependence of freeze-drying and irradiation on biomechanical properties of rat bone

Femurs of Sprague-Dawley rats were subjected to in vitro 3-Mrad irradiation and/or freeze-drying to investigate whether these processes have an order-dependent effect on the biomechanical properties of bone. Four experimental groups were designated-irradiated (RAD); freeze-dried (FD); irradiated, then freeze-dried (RAD/FD); and freeze-dried, then irradiated (FD/RAD). After the various treatments, the bones were inspected for microfractures and then torsion-tested. Microfractures were seen in more than 90% of the specimens that had undergone freeze-drying alone or with irradiation. Regarding the normalized relative ratios of torque, there was a statistically significant difference (P < .05) between the RAD group (1.0) and the 3 other groups (FD, .32; RAD/FD, .40; FD/RAD, .14). Differences among the FD, RAD/FD, and FD/RAD groups were not significant. However, a trend was bones were weaker than FD and noted: FD/RAD RAD/FD bones.     

The sinus node artery: anatomic investigations based on injection-corrosion of 60 sheep hearts

The purpose of this study was to investigate the sinus node artery in the sheep heart to establish adequate baseline information for use in cardiovascular research, and to compare this information with similar data for man. The coronary arteries were exposed by using injection-corrosion casting technique in 60 sheep hearts. Polyester and diluted sulfuric acid were used. When the corrosion was completed, the specimens were photographed. The sinus node artery was single in 59 specimens, and double in one specimen. The artery originated from the right coronary artery (in 42 specimens), left coronary artery (in 16 specimens), and right aortic sinus (in 1 specimen). In the majority of specimens, sinus node artery corresponded to the right superior (anterior) atrial artery. Pericaval termination was common. Mean measurements about the sinus node artery were tabulated. According to the present study, we can state that the sinus node artery in sheep heart is similar to that of humans. Because of the importance of animal research, we suggest that experimental surgical studies of the sinus node artery should be performed on the sheep heart.     

Pravastatin prevents the progression of accelerated coronary artery disease after heart transplantation in a rabbit model

Abstract  This study was designed to investigate the effects of pravastatin (Pr) on accelerated coronary arteriosclerosis in transplanted hearts. The rabbit hearts were transplanted to the recipients' neck heterotopi-cally, and received FK506. The rabbits in group 1 were fed a normal diet (ND), and cholesterol-rich diet (CD) in group 2 and 3. Pr (10 mg/kg) was given to group 3. They were sacrificed at 4 weeks and the severity of m%cardial rejection and arteriosclerosis was assessed and scored histologically. The serum lipid levels were significantly elevated by a CD. However, addition of Pr had no effect on the levels of LDL and total cholesterol (TC). There was no significant difference in m%cardial rejection in each group. Transplanted hearts in group 2 showed more severe arteriosclerotic lesions than those in group 1. Pr treatment in group 3 diminished the severity of coronary arteriosclerosis. Pr may prevent the accelerated coronary arteriosclerosis after heart transplantation without significant changes in TC and LDL.     

Pixel intensity and fractal analyses: detecting osteoporosis in perimenopausal and postmenopausal women by using digital panoramic images.

OBJECTIVE: Pixel intensity values (PI) and fractal dimensions (FD) were compared in selected mandibular regions on digital panoramic images of normal, osteopenic, and osteoporotic perimenopausal and postmenopausal women to evaluate their relative efficacies in detecting osteoporotic-associated bone density changes. STUDY DESIGN: Standardized mandibular angle, body, and canine/premolar (C/PM) regions on 54 charge-coupled device (CCD) digital panoramic images of normal and potentially osteoporotic postmenopausal women were analyzed for PI and FD. Lumbar spine and femoral neck dual-energy x-ray absorptiometry (DXA) on each patient served as the reference standard examination. Pearson correlation coefficients and analysis of variance (ANOVA) were performed. RESULTS: There was significant correlation among PI measurements (P < 0.01), and no significant correlation between FD. C/PM had significantly lower PI than control C/PM (P = 0.049). CONCLUSIONS: Osteoporotic changes in mandibular C/PM cancellous bone were detected in our study population on CCD digital panoramic images by using a robust image analysis paradigm. Future automated application of such image analysis could enable widespread, cost effective screening for osteoporosis in dental settings.