Association between pulmonary hypoplasia and hypoplasia of arcuate nucleus in stillbirth

OBJECTIVE

To investigate lung development and to correlate pulmonary hypoplasia with hypoplasia of the arcuate nucleus in stillbirths.

STUDY DESIGN

We examined 26 stillbirths which occurred after 25 complete gestational weeks. The brainstem and the lung were the particular focus of this study. The brainstem was examined according to the protocol routinely followed in our Institute. As regards the lung examination, the development stage was evaluated on the basis of the correlation between lung and body weight (LW/BW), and according to microscopic parameters, that is, the presence of cartilaginous bronchi up to the distal level and the radial alveolar count (RAC). The normal reference values for the last 3 months of gestation correspond to >0.022 for LW/BW and from 2.2 to 4.4 for RAC.

RESULTS

In 17 cases (65%) pulmonary hypoplasia was observed, characterized by a LW/BW value below 0.022 and RAC below 2.2. In nine cases (35%), microscopic examination of brainstem serial sections showed varying degrees of hypoplasia of the arcuate nucleus (ARCn). In eight cases (31%) the pulmonary hypoplasia was associated with hypoplasia/agenesis of the ARCn.

CONCLUSIONS

This study demonstrated that in about a third of stillbirths there is a congenital hypodevelopment of both lung and arcuate nucleus. In these cases the ARCn hypoplasia would exert a negative effect on respiratory movements in utero and therefore on lung development. When the pulmonary hypoplasia is not accompanied by hypodevelopment of this nucleus the explanation could be a failure to block the inhibitory action of the Kölliker-Fuse nucleus.

Sudden death due to lymphomatous infiltration of the cardiac conduction system

We present the case of a 62-year-old white female with a history of previously treated angioimmunoblastic T-cell lymphoma, who died suddenly 1 day after presentation for presumed tumor recurrence. Postmortem gross examination revealed a 4-cm cardiac mass that was adherent to the free wall of the right atrium. Histologic examination showed extensive infiltration of the cardiac conduction system by lymphoma, which likely lead to fatal arrhythmia. Histological examination revealed systemic dissemination by an Epstein-Barr virus (EBV)-positive large B-cell lymphoma. Careful examination of the cardiac conduction system on serial sections was crucial in documenting the cause of death due to lymphomatous infiltration. As in this patient, lymphomatous infiltration of the heart may produce sudden cardiac death without obvious premortem signs of cardiac compromise. This case illustrates the utility of examination of the cardiac conduction system in necroscopy studies of sudden death.

Cell kinetics of human nasal septal chondrocytes in vitro: importance for cartilage grafting in otolaryngology

In the field of reconstructive plastic surgery, grafts of autologous cartilage are sometimes used to replace damaged or pathologic tissues, particularly in the nose, ear, and trachea. However, this procedure is difficult to apply, especially because of the scarcity of donor sites. In this study, we have cultured and characterized human chondrocytes from human nasal septal cartilage biopsies. The proliferative activity was evaluated by incorporation of 3H-thymidine into deoxyribonucleic acid (DNA) both under normal culture conditions and with different growth factors and serum concentrations. Identification of chondrocytes in culture was performed with immunohistochemistry and production of matrix with specific histochemical indicators. We observed a significant increase of cell kinetics of differentiated chondrocytes, embedded with intense metachromatic matrix, in the presence of transforming growth factor beta, and low concentrations of fetal calf serum. Therefore, in suitable conditions, human chondrocytes obtained even from small specimens can produce in vitro considerable quantities of pure autologous cartilaginous tissue within a few days. This newly formed cartilage can be used as a grafting material in reconstructive surgery, particularly in otolaryngology.

Histopathology of the cardiac conduction system in a case of metastatic pancreatic ductal adenocarcinoma

Metastatic tumor involving the heart occasionally complicates the course of patients with neoplasia. A 70-year-old white male died suddenly. Post-mortem histological examination showed the presence of cardiac metastatic pancreatic ductal adenocarcinoma compressing the cardiac conduction system, which had led to motility, hemodynamic and conductive abnormalities deteriorating into sudden death.

Prognostic significance of different biomarkers (DNA content, PCNA, karyotype) in colorectal adenomas

Immunohistochemical detection of proliferating cell nuclear antigen (PCNA), densitometric analysis of nuclear DNA content and fluorescence in situ hybridization with centromere-specific DNA probes to chromosomes 11 and 17 were carried out on histological sections from 55 colorectal adenomas, in order to identify those adenomas that are more likely to progress to cancer. A considerable variability of PCNA positivity (range: 23-28.2%; mean value: 12.8%), a DNA indexfrom 1 to 2.3 and numerical alterations of chromosome 11 were observed. In particular, 14 out of 55 adenomas (25%), independent of histological type, degree of dysplasia, location and size, showed a DNA-aneuploid content, trisomies and tetrasomies of chromosome 11 and high PCNA index. It was concluded that the combination of some biomarkers (additional chromosomes 11, high PCNA and DNA indices) may allow identification of more aggressive colorectal adenomas with increased ability to undergo malignant transformation.

Brain stem lesions in the sudden infant death syndrome: variability in the hypoplasia of the arcuate nucleus

In the present study we investigated quantitatively the incidence of hypoplasia of the arcuate nucleus (ARCn) of the medulla oblongata, reported earlier [Gozal D, Hathout GM, Kirlew KAT (1994) J Appl Physiol 76:207], as well as its distribution in 62 cases of sudden infant death syndrome (SIDS; mean age 14 postnatal weeks, 39 male and 23 female) and 25 controls (mean age 16 postnatal weeks, 14 male and 11 female), using detailed histopathological and morphometric analyses performed on serial sections of medulla oblongata. The SIDS cases were divided into four subtypes: SIDS A (27 cases, 43%) with histologically well-developed ARCn; SIDS B (16 cases, 26%) with severe bilateral hypoplasia along the whole length; SIDS C (11 cases, 18%) with partial bilateral hypoplasia, located mainly in the lateral portions of the caudal two thirds of the nucleus, and SIDS D (8 cases, 13%) with right monolateral hypoplasia of the ARCn. ARCn hypoplasia was detected in 56% of cases (35 cases). Three-dimensional volume reconstruction showed that in the SIDS A victims the mean volume was analogous to controls, whereas in the SIDS group with ARCn hypoplasia, severe or partial, the mean volume was significantly different from controls on both sides of the medulla oblongata (SIDS B group: P=0.003, P=0.002; SIDS C group: P=0.007, P=0.008). The mean ARCn volume in the SIDS D group was statistically significant only on the right side ( P=0.005). We also observed reduced neuron density of the ARCn, associated with a decrease in the total number of neurons over the whole length of the nucleus itself. On the basis of the morphometric results of neuronal population in the different portions of the ventrolateral medulla in SIDS cases, we hypothesized that infants without the full complement of neurons and neuropil (ARCn hypoplasia) are at risk for SIDS because they are unable to develop appropriate cardioventilatory control during this crucial developmental period.

Hypoplasia of medullary arcuate nucleus in unexpected late fetal death (stillborn infants): a pathologic study

OBJECTIVES

To evaluate the frequency, morphology, and pathogenesis (primary or secondary) of the abnormally developed medullary arcuate nucleus (ARCn) in stillbirths.

METHODS

We examined 26 stillbirths (24 antepartum, 2 intrapartum) that had a gestational age between 25 and 40 weeks and a normal karyotype. All of the stillborns were described as well-developed, with body length and weight proportional to their gestational age. Each case was submitted to complete autopsy examination, which included a systematic gross and microscopic evaluation of the body, the placental disk, and the umbilical cord and membranes. The brainstem was the particular focus of the histologic examination. The study of the various nuclei (nucleus hypoglossus, dorsal vagus motor nucleus, tractus solitarii nucleus, nucleus ambiguus, trigeminal tractus and nucleus, arcuate nucleus, and ventrolateral reticular formation and its neurons and parabrachial/Kölliker-Fuse complex) was performed on transversal serial sections through the entire pons and medulla oblongata. The histologic analysis was supplemented by volumetric reconstruction and immunohistochemical detection of both apoptosis and proliferating cell nuclear antigen.

RESULTS

Histologic examination showed abnormalities of the medulla oblongata ARCn in 9 fetuses (35%). In 8, a marked hypoplasia was evident, characterized by a volume reduction of the nucleus accompanied by neuronal depletion, whereas in 1 fetus the nucleus was completely absent (agenesis). The absence of gliosis, the negativity of the proliferating cell nuclear antigen analysis, and the similarities in apoptotic indices between the hypoplastic and well-developed arcuate are in keeping with a primary developmental defect. This anomaly is frequently associated with hypoplasia of the reticular formation and chronic hypoxia.

CONCLUSIONS

A high frequency of hypoplasia of the ARCn occurs in fetuses who have died "sine causa," ie, in a similar manner to that observed in sudden infant death syndrome. Chemoreceptors, although not involved in reflexogenic oxygenation in fetal life, become of vital importance intrapartum and postpartum; therefore, whenever impaired in the course of development, chemoreceptors may underlie cardioventilatory abnormalities critical to sudden infant death syndrome.

Characterization of myocardial hypertrophy by DNA content, PCNA expression and apoptotic index

BACKGROUND

At present little is known about the biological basis of cellular alterations in myocardial hypertrophy. The present study aims to analyze proliferating cell nuclear antigen (PCNA) expression, DNA content and apoptosis, in several types of myocardial hypertrophy in order to define the biological characteristics of this process.

METHODS

The biological parameters were investigated in normal hearts (n=4) and in 21 cases of left ventricular myocardial hypertrophy related to pressure overload (n=7), post-infarction remodeling (n=8) and hypertrophic cardiomyopathy (HCM) (n=8).

RESULTS

The analyzed biomarkers were similar in hypertension and in remodeling, with a very high apoptotic index (mean values: 8.1 and 8.5%, respectively), a low PCNA positivity (mean values: 1.8 and 1.6%) and a prevalent diploid DNA content (DNA index: 1.2). Conversely, HCM showed a high mean PCNA index (21.2%) associated with a prevalence of hyperdiploid myocytes (DNA index: 1.8) and a low number of apoptotic cells (mean value: 1.7%).

CONCLUSIONS

There are significant biological differences between hypertrophy in HCM and that related to arterial hypertension and post-infarction remodeling. Therefore, the combined evaluation of DNA content, PCNA and apoptotic indices could provide a powerful diagnostic tool in doubtful cases of myocardial primary or secondary hypertrophy and open new avenues in the clinical treatment of these entities.

Expression of apoptosis and proliferating cell nuclear antigen (PCNA) in the cardiac conduction system of crib death (SIDS)

Aim of this study is to determine the expression of apoptosis and Proliferating Cell Nuclear Antigen (PCNA) in the cardiac conduction system in crib death and explained death (ED) cases. Postnatal morphogenesis of the conducting tissue is an important part of its normal development. In the atrio-ventricular node (AVN) and His bundle (HB) it consists of degeneration, cell death and replacing in an orderly programmed way. However, its nature and its relation to crib death is not yet fully explained. Apoptosis and PCNA were investigated in 8 heart conduction systems of infants dying of crib death and in 3 conduction systems of infants dying of ED as controls. The cardiac conduction system was removed in two blocks: the first included the sino-atrial node (SAN) and the crista terminalis, the second contained the atrio-ventricular node (AVN), His bundle (HB), bifurcation, and bundle branches. In the conduction systems as well as in the common myocardium the PCNA Labeling Index (PCNA-LI) was found to be negative in all cases. The apoptotic indices (AI) in SIDS and in ED were found to have no statistically significant differences (p>0.05). The SAN, in both groups, showed an AI similar to the one detected in common myocardium. In almost all cases, TUNEL labeling was detected in peripheral region of the AVN, close to the atrial myocardium. The AI was higher in the AVN, HB and the initial tract of bundle branches than in the common myocardium (p<0.05; Student's t test).

The role of different biomarkers (DNA, PCNA, apoptosis and karyotype) in prognostic evaluation of superficial transitional cell bladder carcinoma

BACKGROUND

In order to clarify the variable behaviour of transitional cell bladder carcinomas (TCBC) with same clinico-pathologic pattern, we investigated the prognostic significance of various biomarkers (PCNA, DNA, apoptosis, karyotype).

MATERIALS AND METHODS

We studied 177 superficial TCBC (stage T1) undergoing transurethral resection (TUR). Analysis of biological indicators was performed on serial paraffin sections: DNA by static cytometry, karyotype by fluorescence in situ hybridisation (FISH), PCNA and apoptosis by immunohistochemistry.

RESULTS

The most salient results are represented by prevalence of diploidy (56%), a mean PCNA labeling index (PCNA-LI) of 8.2%, nonrandom trisomies and tetrasomies of chromosome 7, and a high presence of apoptosis (in 72% of cases). These data were not related to histological grading. Multivariate analysis showed that only PCNA-LI is a an independent prognostic marker for patient survival (p = 0.01). Besides, we observed a worse prognosis in the presence of both very high PCNA indices and low or absent apoptosis.

CONCLUSIONS

The results of this study suggest that tumor prognostic potential in TCBC should be evaluated on the basis of the association between PCNA cell kinetics and cell apoptosis information.

[Proliferative activity and chromosomal alterations of smooth muscle cells in atherosclerosis]

Atherosclerosis is the most frequent cause of death in industrialized countries. Lesions are characterized by lipid deposits, focal thickening of the arterial wall with proliferation of smooth muscle cells (SMC), mononuclear infiltrates and neoformed vessels. In this paper, we studied the proliferative characteristics and cytogenetic alterations of SMC. These cells, expressing specific muscular actin, were diploid with an increased proliferative index for PCNA. A high percentage of SMC showed intense expression of p53. There were signs of chromosomal instability, being the most frequent findings chromosome 7 trisomy and chromosome 11 monosomy. Additionally, the gene for FGF-3 showed a marked amplification. These findings strongly suggest that SMC proliferation is active, and is related to the accumulation or mutation of the p53 oncoprotein. It also presents specific chromosomal alterations in close relation with growth factors. According to these findings SMC hyperplasia in the atherosclerosis plaque may be considered as a cellular clonal expansion.

Chromosomal alterations in atherosclerotic plaques

Alterations of chromosomes 7 and 11 have been involved in the progression of atherosclerosis. Twenty-three carotid endarterectomy specimens were studied for the presence of alterations in chromosomes 7 and 11, and fibroblastic growth factor-3 (FGF-3) gene amplification. Besides classic histological stainings, immunophenotyping of cellular and vascular components and fluorescence in situ hybridization (FISH) were performed. At the caps, unstable plaques (n=18) showed inflammatory infiltration of macrophages, smooth muscle cells, and T-lymphocytes. Specifically in these regions, the FISH showed varying percentages of trisomy (15/18) and tetrasomy (8/15) of chromosome 7. In four cases polisomy 7 was noted in some nuclei. Monosomy of chromosome 11 and gene amplification of FGF-3 gene was observed. The FISH of the five stable plaques and normal arterial walls showed no chromosome alterations; furthermore, chromosome 3, which is not involved in atherosclerotic progression, presented a normal ploidy of smooth muscle cells in stable and unstable plaques and normal arterial walls. In conclusion, chromosome 7 and 11 alterations and FGF-3 gene amplification are components of unstable plaques, and might contribute to the evolution of stable plaques into complicated plaques.

Inflammatory cells, apoptosis and Chlamydia pneumoniae infection in atherosclerosis

Chlamydia pneumoniae (CP), chromosomal alterations and apoptosis were suggested as contributing factors in the pathogenesis of atherosclerosis. Early (EP) and unstable plaques (UP) were studied in order to assess infiltrate composition, the apoptotic index, chromosome 7 stability and to investigate the concurrent presence of CP in EP and UP. Paraffin embedded sections of three iliac arteries and four aortas from young donors (EP), and four coronaries and nine carotid arteries (UP) were used. Aside from histological techniques, immunophenotypification for macrophages, T and B cells, smooth muscle and endothelial cells; FISH and DNA nick end labeling were performed. The amplifications with PCR for CP infection were negative in all specimens. In the EP, a focal myointimal thickening with foam cells and scarce smooth muscle cells was observed. Macrophages were most frequent in the intima (10.8%) while T and B cells were found in 2.3 and 1.5%. In the UP a thin cap covering a lipid-rich core with widespread vascularization and with severe luminal obstruction was observed. Macrophages were increased (21%), and T (1.5%) and B cells (3.5%) in the caps and inner areas of the lipid cores. At these sites, the FISH showed trisomy and tetrasomy of chromosome 7 and apoptosis was very frequent (10-30%). Macrophages in intimal lesions is one of the most prominent, consistent and permanent features in EP, and an elevated apoptotic index and chromosome 7 instability might contribute to evolution from stable to complicated plaques, while CP seems to play no role. However, further studies are needed with more cases to confirm this last observation.

Sudden Infant Death Syndrome (SIDS): a study of cardiac conduction system

The theory that Sudden Infant Death Syndrome (SIDS) may be related to lethal cardiac arrhythmias or heart block due to structural abnormalities of the conduction system is attractive and still of particular interest. We analyze 69 autopsied cases of SIDS (46 males and 23 females, infants ranging in age from 3 to 365 days) and 24 age-matched cases of explained death (ED) as controls (16 males and 8 females), infants who died from extracardiac cause (cerebral and respiratory). SIDS and ED groups were divided into three subgroups according to the age: (A) from 3 to 60 days; (B) from 61 to 120 days; (C) from 121 to 365 days. Histological observations were focused on the cardiac conduction system (CCS) which was examined on serial sections with the technique devised by one of the present authors (L. Rossi). The following findings were observed: resorptive degeneration (97.10% of SIDS, 75% of ED), His bundle dispersion (33. 33% of SIDS, 16.66% of ED), Mahaim fibers (21.73% of SIDS, 8.3% of ED), cartilaginous meta-hyperplasia (5.79% of SIDS, 4.16% of ED), persistent fetal dispersion (24.63% of SIDS, 16.66% of ED), intramural right bundle (20.29% of SIDS, 25% of ED), left sided His bundle (20.29% of SIDS and 8.3% of ED), hemorrhage of the atrio-ventricular junction (15.94% of SIDS), septation of the bifurcation (13.04% of SIDS), atrio-ventricular node (AVN) dispersion (7.24% of SIDS), sino-atrial node hypoplasia (5.79% of SIDS), Zahn node (1.45% of SIDS), His bundle hypoplasia (1.45% of SIDS), intramural left bundle (1.45% of SIDS), AVN dualism (2.89% of SIDS), and His bundle dualism (2.89% of SIDS, 4.16% of ED). Only the presence of resorptive degeneration was significantly higher in SIDS than in ED cases (p = 0.004). Regarding the subgroups, the only significant difference was the higher presence of intramural right bundle in SIDS-A than in SIDS-B (p = 0.01). Despite the non-specificity of most of these findings, we believe that these changes, associated with particular conditions and/or neurovegetative stimuli, could cause potentially malignant arrhythmias. These data suggest the need for an accurate approach and examination of the cardiac conduction system in all cases of sudden death in infancy

PCNA immunostaining as a valid alternative to tritiated thymidine-autoradiography to detect proliferative cell fraction in transitional cell bladder carcinomas

BACKGROUND

The thymidine labeling index (T-LI) evaluated with the autoradiographic technique on fresh specimens is the most objective and specific marker of tumor proliferative cell fraction. In this study we investigated T-LI and PCNA expression in 68 cases of transitional cell bladder carcinomas in order to evaluate whether PCNA immunostaining in paraffin sections could be a valid alternative to autoradiographic methods for cell kinetic detection. Immunohistochemistry was applied after different fixatives: usual formalin, neutral 4% buffered formalin and Bouin. The results revealed that only in buffered formalin-fixed tumor specimens, considering the most darkly stained cells, the PCNA-LI in all cases overlapped with T-LI. Higher values than those observed with autoradiography were detected in PCNA values obtained after usual formalin fixation whereas no or faint PCNA staining was seen in material fixed in Bouin. Thus, only cells with strong PCNA staining can be considered as significant in evaluating the proliferative activity in transitional cell bladder carcinoma. By using immunohistochemical methods it should thus be possible to overcome many of the inherent difficulties of autoradiography and likewise to obtain accurate and significant information on the biological aggressiveness of bladder tumors and consequently of patient prognosis.

Severe hypoplasia of medullary arcuate nucleus: quantitative analysis in sudden infant death syndrome

The human arcuate nucleus (ARCn) is postulated to be homologous to ventral medullary cells involved in chemoreception, and respiratory and blood pressure responses. Abnormalities in central respiratory control may result from dysfunction of this anatomic ventral area. We evaluated the changes of the neuronal population of the medullary ARCn in infants victims of the sudden infant death syndrome (SIDS). In this study we tested the hypothesis that anatomical deficiency of the ARCn is associated with SIDS. The volume and neuronal density of the ARCn were morphometrically quantified with an image analyzer in 36 cases of SIDS and 12 age-matched controls. We found a marked hypoplasia in the SIDS ARCn compared to controls and, particularly, in 11 SIDS cases (30%) in which the ARCn exhibited a severe hypoplasia, being almost totally absent. Three-dimensional reconstructions and morphometric measurements of ARCn confirmed this marked hypoplasia in all the serial sections examined (P = 0.0001) and the reduced neuronal density (P = 0.0025) in relation to control cases. In conclusion these abnormalities observed in the ARCn are consistent with the idea that ARCn dysfunction plays an important role among the causative factors of sudden infant death. The hypoplasia of the ARCn represents the most frequent congenital abnormality in our experience, and can be a plausible morphological substrate for a subset of SIDS.

p53 over-expression and its correlation with PCNA index in nasal polyps

Our knowledge about the etiopathogenesis of nasal polyps (Nps) is still limited. In this study, in order to define the biological features of these neoformations, we investigated with immunohistochemistry the p53 over-expression and the proliferating cell nuclear antigen (PCNA) in 32 cases of Nps and in normal mucosa of 11 control cases. The evaluation of PCNA showed a wide range of indices (0.5-18.2%) with a mean value (6.8%) significantly higher than in normal mucosa (2.9%). Over-expression of the p53 oncoprotein, observed in 50% of Nps, was statistically related to a high PCNA-index (> 6.8%). Our results suggest that Nps can behave, in a high percentage of cases, like tumours.

Prognostic significance of different biomarkers in non-small cell lung cancer

The purpose of our study was to examine the prognostic significance of different biomarkers [DNA content, proliferating cell nuclear antigen labeling index (PCNA-LI), p53 mutation and apoptosis], in 152 surgically resected non-small cell lung cancer (NSCLC). The ploidy was carried out by densitometry; PCNA-LI, p53 and apoptosis were determined with immunohistochemistry. The results were correlated to histology, stage and patient survival. A considerable variability of the PCNA indices, ranging from 0 to 33.5% with a mean value of 7.0%, was found. DNA evaluation showed a prevalence of aneuploid tumors (62%) with a DNA index >1. Overexpression of p53 protein and apoptotic positivity were observed in low percentages of cases (16% and 32% respectively). Only stage and PCNA-LI were found to be significant prognostic factors on multivariate analysis. PCNA was superior to stage in predicting shortened survival of patients with NSCLC. PCNA immunostaining can be applied on a routine basis in formalin-fixed, paraffin-embedded samples of NSCLC to predict patient prognosis and thus to identify patients in need of additional postoperative therapies.

Evidence for apoptosis in non-small cell lung carcinoma. Relationship with cell kinetics and prognosis

OBJECTIVE

To investigate cell death via apoptosis in non-small cell lung carcinoma (NSCLC) and its correlation with proliferative indices and follow-up.

STUDY DESIGN

In 38 cases of NSCLC (21 squamous cell carcinomas and 17 adenocarcinomas) we analyzed apoptosis by nuclear morphology and in situ DNA fragmentation end labeling and the cell kinetics by an autoradiographic method with tritiated thymidine and by immunohistochemistry with anti-proliferating cell nuclear antigen (anti-PCNA) antibodies. We also evaluated mitotic frequency. Apoptotic index (AI) was correlated with the thymidine and PCNA labeling indices (T-LI and PCNA-LI, respectively) and with the mitotic index.

RESULTS

The percentage of proliferating cells (T-LI range, 0.1-20.1%; PCNA-LI range, 0-14.7%) was generally considerably higher than that of apoptotic cells (range, 0-8%) and of mitotic cells (range, 0.1-1%). Survival at six years was significantly higher in patients with high levels of apoptosis and low T-LI values.

CONCLUSION

AI and T-LI are independent and very useful prognostic factors in NSCLC. A high percentage of proliferating cells in terms of T-LI correlates with poor prognosis, whereas a high AI indicates a favorable outcome.

Proliferating cell nuclear antigen (PCNA) and apoptosis in hyperacute and acute myocardial infarction

The aim of this study was to determine whether cell proliferation and/or apoptotic cell death occur in hyperacute and acute infarction. Proliferating cell nuclear antigen (PCNA) and apoptosis were investigated in ten autoptic hearts within a few hours of infarction and in three normal hearts as controls. The PCNA Labeling Index (PCNA-LI) ranged from 0 to 3.1 in hyperacute infarction (mean 1.38), from 0.3 to 4 in acute infarction (mean 2.04) and from 0 to 1.2 in controls (mean 0.7). Although the results were not statistically significant, PCNA-LI was higher in acute than in hyperacute myocardial infarctions; and it was higher in hyperacute infarctions than in controls. Regarding apoptosis, the Apoptotic Index (AI) in hyperacute infarctions ranged from 0.7 to 3 (mean 1.78), in acute infarctions from 0.9 to 5 (mean 3.24) and in controls from 0 to 0.4 (mean 0.1). The AI was significantly higher in hyperacute and acute infarctions than in controls (p < 0.05).

Pathology of the heart and conduction system in a case of sudden death due to a cardiac fibroma in a 6-month-old child

A 6-month-old female infant considered to be in good health died suddenly and unexpectedly. Post-mortem examination was requested, with clinical diagnosis of sudden infant death syndrome. Gross examination revealed, however, the presence of a cardiac mass 4.5 X 4 x 3.5 cm in diameter. Histological examination of the heart confirmed the presence of a cardiac fibroma. In the present case, the sudden death could have been due to the left ventricular outflow obstruction, as much as to conductive disturbances caused by overstretching and compression of the atrioventricular node and of the bundle branches. Hemodynamic and conductive abnormalities are presumed to have provoked bradycardia degenerating into ventricular fibrillation and sudden death. Necroscopy studies of sudden death should always include histological examination of the cardiac conduction system but seldom do.

The prognostic value of cell proliferation in colorectal adenomas assessed with tritiated thymidine and anti-proliferating cell nuclear antigen

We analyze the cell kinetics of colorectal adenomas by tritiated thymidine (3HTdR) autoradiographic method and anti-proliferating cell nuclear antigen (PCNA) antibodies. A total of 46 patients who underwent prior endoscopic polypectomy for colorectal adenomas were reevaluated by colonoscopy for 4 years. Thymidine labeling index (T-LI) in index adenomas ranged from 1.40 to 38.0% (median value: 10. 75%); PCNA labeling index (PCNA-LI) in index adenomas ranged from 0 to 27.0% (median value: 1.95%). Among the 46 patients studied, 16 developed recurrent adenomas (Group A) and 30 were free of recurrent adenomas (Group B). The T-LI and PCNA-LI comparisons between Groups A and B were statistically significant (p < 0.0001, chi2 test). These results demonstrate that T-LI and PCNA-LI in colorectal adenomas might be helpful to predict the development of metachronous adenomas and hence to plan the follow-up of patients with adenomatous polyps after polypectomy.

Sudden and unexpected infant death due to an hemangioendothelioma located in the medulla oblongata

Herein, we report the case of a 4-month-old male infant dying suddenly and unexpectedly. Post mortem examination was requested with clinical diagnosis of Sudden Infant Death Syndrome (SIDS). Histological examination showed instead the presence of an hemangioendothelioma located in the medulla oblongata. Sudden unexpected death is the commonest form of death among babies between 1 month and 1 year of age. Although the vast majority of these fatalities are related to SIDS, a very small percentage is due to primary neoplasm. Necroscopy studies of sudden infant death should always include an accurate histological examination of the medulla oblongata on serial sections but seldom do.

Carotid rupture and intraplaque hemorrhage: immunophenotype and role of cells involved

BACKGROUND

A complete immunohistochemical characterization in complicated carotid plaques is still lacking. The cellular components of 165 carotid endarterectomy specimens were analyzed to assess their role in the pathogenesis of plaque rupture and intraplaque hemorrhage without rupture.

METHODS AND RESULTS

The fibrous caps at the sites of plaque rupture showed CD68+ macrophages, T-lymphocytes, and scarce B-lymphocytes. Ruptured plaques showed mononuclear infiltrates in the caps, shoulders, and bases of the plaques in 85% of the cases. Only 46% of nonruptured plaques showed such infiltrates (P <.0001). Two types of lipid cores were recognized: avascular or mildly vascularized and highly vascularized. The vessels of the latter type reacted with CD31 and CD34. In 57.5% of the cases, the base and the shoulders of the plaques showed neoformed, CD34+ vessels, often surrounded by mononuclear infiltrates. Intraplaque hemorrhage without rupture had highly vascularized lipid cores in all cases. T-lymphocytes and macrophages were in close contact with neoformed vessels.

CONCLUSIONS

Plaque rupture is characterized by mononuclear cell infiltration of the caps, whereas intraplaque hemorrhage without rupture is characterized by extensive vascularization of the plaque.