Sporadic human renal tumors display frequent allelic imbalances and novel mutations of the HRPT2 gene.

Inactivation of the HRPT2 gene encoding parafibromin was recently linked to the familial hyperparathyroidism-jaw tumor syndrome. Patients with this syndrome carry an increased risk of parathyroid and renal tumors. To determine the relevance of HRPT2 for sporadic renal tumors, clear cell, papillary and chromophobe renal cell carcinomas as well as oncocytomas and Wilms tumors were analysed for HRPT2 gene alterations. Loss of heterozygosity (LOH) of HRPT2 was found in seven of 56 (12.5%) clear cell, three of 14 (21%) papillary, six of 10 (60%) chromophobe renal cell carcinomas, three of eight (38%) oncocytomas and four of 10 (40%) Wilms tumors. In addition, two novel HRPT2 point mutations, causing K34Q and R292K changes in parafibromin, were detected in one clear cell carcinoma and one Wilms tumor, respectively. These tumors displayed LOH of the remaining wild-type allele, but interestingly no von Hippel-Lindau (VHL) mutation. Functional analysis revealed that the K34Q mutant species of parafibromin is, unlike wild-type protein, defective in suppressing cyclin D1 expression in vivo. Taken together, these results suggest that renal cancer-associated mutations in parafibromin occur in the absence of VHL mutation, which in turn may contribute to constitutively elevated cyclin D1 expression and abnormal cell proliferation.

Characterization of an organic anion-transporting polypeptide (OATP-B) in human placenta.

Organic anion-transporting polypeptides (OATPs) are a family of multispecific carriers that mediate the sodium-independent transport of steroid hormone and conjugates, drugs, and numerous anionic endogenous substrates. We investigated whether members of the OATP gene family could mediate fetal-maternal transfer of anionic steroid conjugates in the human placenta. OATP-B (gene symbol SLC21A9) was isolated from a placenta cDNA library. An antiserum to OATP-B detected an 85-kDa protein in basal but not apical syncytiotrophoblast membranes. Immunohistochemistry of first-, second-, and third-trimester placenta showed staining in the cytotrophoblast membranes and at the basal surface of the syncytiotrophoblast. Trophoblasts that reacted with an antibody to Ki-67, a proliferation-associated antigen, expressed lower levels of OATP-B. OATP-B mRNA levels were measured in isolated trophoblasts under culture conditions that promoted syncytia formation. Real-time quantitative PCR estimated an 8-fold increase in OATP-B expression on differentiation to syncytia. The uptake of [(3)H]estrone-3-sulfate, a substrate for OATP-B, was measured in basal syncytiotrophoblast membrane vesicles. Transport was saturable and partially inhibited by pregnenolone sulfate, a progesterone precursor. Pregnenolone sulfate also partially inhibited OATP-B-mediated transport of estrone-3-sulfate in an oocyte expression system. These findings suggest a physiological role for OATP-B in the placental uptake of fetal-derived sulfated steroids.

Increased cerebral infarct volumes in polyglobulic mice overexpressing erythropoietin.

There is increasing evidence that erythropoietin (Epo) has a protective function in cerebral ischemia. When used for treatment, high Epo plasma levels associated with increases in blood viscosity, however, may counteract beneficial effects of Epo in brain ischemia. The authors generated two transgenic mouse lines that overexpress human Epo preferentially, but not exclusively, in neuronal cells. In mouse line tg21, a fourfold increase of Epo protein level was found in brain only, whereas line tg6 showed a dramatic increase of cerebral and systemic transgene expression resulting in hematocrit levels of 80%. Cerebral blood flow (CBF), as determined by bolus tracking magnetic resonance imaging, was not altered in the tg6 line. The time-to-peak interval for the tracer, however, increased approximately threefold in polyglobulic tg6 mice. Immunohistochemical analysis revealed an increase in dilated vessels in tg6 mice, providing an explanation for unaltered CBF in polyglobulic animals. Permanent occlusion of the middle cerebral artery (pMCAO) led to similar perfusion deficits in wild-type, tg6, and tg21 mice. Compared with wild-type controls, infarct volumes were not significantly smaller (22%) in tg21 animals 24 hours after pMCAO, but were 49% enlarged (P < 0.05) in polyglobulic tg6 mice. In the latter animals, elevated numbers of Mac-1 immunoreactive cells in infarcted tissue suggested that leukocyte infiltration contributed to enlarged infarct volume. The current results indicate that moderately increased brain levels of Epo in tg21 transgenic mice were not sufficient to provide significant tissue protection after pMCAO. The results with tg6 mice indicate that systemic chronic treatment with Epo associated with elevated hematocrit might deteriorate outcome after stroke either because of the elevated hematocrit or other chronic effects.

Autoaggressive inflammation of the myenteric plexus resulting in intestinal pseudoobstruction.

After a 3-year history of severe constipation, a 16-year-old girl required surgery to be relieved of impacted stools. Histologic examination showed ganglionitis in the myenteric plexus of the large bowel and ileum, whereas the submucosal plexus was spared. At this time, antineuronal nuclear antibodies (ANNA-1, anti-Hu) were found at high titer in the serum of the patient. One and a half years earlier, a paravertebral ganglioneuroblastoma had been removed. Histologic examination had shown undifferentiated neuroblasts and morphologically mature ganglion cells with both cell types embedded in an inflammatory infiltrate morphologically similar to the lymphoplasmocytic infiltration seen in the myenteric plexus. The patient's serum was found to bind to nuclei of mouse intestinal tract neurons, thus fulfilling defining criteria for ANNA-1. The serum also reacted with antigens of defined molecular weight in a Western blot, thus fulfilling defining criteria for anti-Hu. Expression of the Huantigen could be visualized in the nuclei of the patient's tumor cells by immunohistochemistry. These tests showed that an antitumor inflammatory response was the cause of the bowel disease. This is the first report of a tumor from the neuroblastoma group that caused paraneoplastic intestinal pseudoobstruction. Ganglionitis and subsequent aganglionosis are the hallmark of the morphologic diagnosis which cannot be obtained by suction biopsy in patients with intact submucosal plexus. Instead, serum testing for autoantibodies can reveal the etiology.

Hypoplastic thymus and T-cell reduction in EECUT syndrome.

We report on a patient with EEC/EECUT syndrome and concomitant hypoplasia of the thymus and reduction of T cells in secondary lymphatic organs. The patient was born prematurely at 35 weeks of gestational age and exhibited ectodermal dysplasia, ectrodactyly, cleft palate and urinary tract abnormalities. On the left side, a large ureterocele was present. On the right side, an atretic ureter was found. Both conditions had led to intrauterine hydronephrosis, renal dysplasia, oligohydramnios, pulmonary hypoplasia, and death of the child. Ureteral malformations are thought to be of epithelial origin. Autopsy showed only small rudiments of thymic tissue containing single epithelial cells, but were completely devoid of Hassall corpuscules. Again, this clearly points to an ectodermal defect. Although there was severe reduction of T cells in secondary lymphatic organs, the thymic defect would not have necessarily led to immunological deficiency; perhaps this is the reason that an epithelial defect in the thymus of patients with EEC syndrome has not yet been reported. With regard to an updating of the diagnosis of the EEC/EECUT syndrome, an "EEC/EECUT plus" syndrome is suggested.

Lethal multiple pterygium syndrome: suggestion for a consistent pathological workup and review of reported cases.

We report on 2 brothers with lethal multiple pterygium syndrome (LMPS) born to non-consanguineous parents as late spontaneous abortions. Both fetuses presented with massive nuchal edema, and facial anomalies including cleft palate and broad ribs. Apparently, several subgroups of LMPS exist. Differentiation is difficult, as there is no consistent agreement on a workup protocol for autopsies. We compared the findings in the literature on cases with LMPS, and we suggest a standardized workup as an initial step for more efficient differentiation between various subgroups.

Diaphragmatic defects, limb deficiencies, and ossification defects of the skull: a distinctive malformation syndrome.

We report on prenatal and postnatal findings in 4 consecutive fetuses with a pattern of severe congenital anomalies who were born to a healthy nonconsanguineous couple. The spectrum of malformations includes diaphragmatic defects, hypoplastic lungs, omphalocele, limb deficiencies, syndactyly of toes, and ossification defects of the skull. This specific spectrum of anomalies is not fully compatible with that of any established syndrome. No prenatal exposure to any possible teratogen was found. Family history is suggestive for autosomal recessive inheritance, even though germ-line mosaicism in one of the parents cannot completely be excluded.

Augmentation of fetal granulopoiesis with chorioamnionitis during the second trimester of gestation.

Chorioamnionitis is a major hazard to pregnancy in the second trimester. It affects the fetomaternal unit, causing febrile illness in the mother. The fetus eventually is expelled because uterine contractions can no longer be suppressed after a certain stage of the disease. To determine the effects of chorioamnionitis on the fetus we examined fetal hematopoiesis, which is, for the most part, located extramedullarily during the second trimester of gestation. The study was performed morphometrically on sections of fetal tissues; the results are given as an increase of cells per square millimeter. In chorioamnionitis the fetuses (n = 18) showed increased granulopoiesis in the parenchyma of the liver (x12), in the spleen (x 5), in the portal triads of the liver (x3), and in the bone marrow (x1.35). Erythropoiesis and total hematopoiesis were reduced in all compartments. Inflammatory disease in the mother other than chorioamnionitis did not alter fetal hematopoiesis (n = 13). Under normal conditions fetal liver granulopoiesis is at a very low level within the sinusoids, but an early and substantial increase can be seen most easily in this location during infection; chorioamnionitis can thus be diagnosed from the fetal liver alone. Alterations in fetal hematopoiesis might be caused by cytokines generated at the fetomaternal interface during chorioamnionitis.

Chronic deciduitis in the placental basal plate: definition and interobserver reliability.

This study tested whether concordance could be achieved for abnormal inflammation in the basal decidua of placental specimens among 6 pathologists experienced in placental pathology. Thirty microscope slides were evaluated by the pathologists for chronic deciduitis. They also scored the severity and extent of inflammation and the presence of plasma cells. No definition of chronic deciduitis was provided. Concordance (5/6 or 6/6 agreement) was achieved in 23 cases (76%). Spearman's rank correlation showed that the diagnosis of chronic deciduitis was almost identical to the assessment of the severity of the inflammation. A regression analysis showed that the perception of severity (and hence chronic deciduitis) was influenced by the other 2 variables, extent and plasma cells. The results were shared with the pathologists, and 25 cases (excluding those with previous 6/6 consensus) were reevaluated. Concordance was now achieved in the 83% of those remaining cases. Using a threshold based on the severity and the extent of lymphocytes, and the presence of plasma cells, pathologists are able to diagnose chronic deciduitis with sufficient concordance to be of value in clinical correlation studies.

Incidental choriocarcinoma confined to a near-term placenta.

A large solitary choriocarcinoma was found incidentally in a placenta from a 36-week gestation following caesarean section performed because of intrauterine fetal distress. Macroscopically, there appeared to be a large old infarct in the centre of the placenta proper. Microscopically, there was extensive central necrosis with a rim of viable trophoblastic tumour that had the typical morphology of choriocarcinoma. Although the tumour was floating within maternal blood and was also detected in direct contact with fetal vessels, no metastatic disease was reported in the subsequent 1 1/2 years either in the mother or in the child. Placental infarcts are often not examined histologically, and an intraplacental tumour may thus be missed. Central friability and an unusual colour should alert the pathologist and lead to histological clarification. The management of an incidentally discovered intraplacental choriocarcinoma should be an expectant one, consisting of extensive workup for any evidence of metastases and serial beta-HCG measurements in both mother and child.

Aberrant positioning of trophoblast and lymphocytes in the feto-maternal interface with pre-eclampsia.

Pregnancy represents the growth of an allograft where fetal trophoblast cells evade immune rejection and invade maternal tissue. There should be a balance between fetal trophoblast and maternal immune-responsive cells and alterations in the proportion of these cells may relate to pregnancy disorders. To test this, the decidual tissue of placental bed biopsies was examined and trophoblast cells and lymphocytes were quantified morphometrically; spiral arteries were classified as unchanged, transformed or affected by acute atherosis. Normal pregnancy (n=19) was characterized by the transformation of about one half of all spiral arteries within the placental bed. We found that 40% of all lymphocytes were CD56+ uterine NK cells and 60%, CD3+ T-lymphocytes; about 30% of these were CD8+ T cells. Intrauterine growth retardation in the context of preeclampsia (n=15) was accompanied by reduced trophoblast numbers within smaller and more tortuous arteries and an increase in the proportion of CD56+ uterine NK cells and CD8+ T lymphocytes in the decidua (70% of all CD3+ cells). In the case of pre-eclampsia without fetal growth retardation (n=14) no increase in CD56+ uterine NK cells was seen, while CD8+ T lymphocytes were significantly increased compared with the normal level (50% of all CD3+ cells). Fetal growth retardation is associated with poor transformation of spiral arteries and characterized by an increase of uterine NK cells. Symptoms of pre-eclampsia are independently associated with an increase in the cytotoxic T subset of decidual lymphocytes. Pre-eclampsia and related fetal growth retardation are seemingly caused by an enhancement of the maternal cytotoxic defence against the fetal allograft.

Fetal varicella syndrome: disruption of neural development and persistent inflammation of non-neural tissues.

Primary varicella zoster virus (VZV) infection during pregnancy is rare. If it occurs between the 8th and 20th week of gestation, fetal varicella syndrome results in 1-2% of the fetuses. We report about a varicella infection that affected a pregnant mother in the 12th week of gestation. At 33 weeks, a premature girl was born with destruction of neurons in spinal cord, spinal ganglia and plexus myentericus, and secondary developmental disturbance including mummification of one arm and segmental intestinal atresia. The brain did not show any abnormalities. However, VZV DNA could be detected by PCR in tissues from the brain and spinal ganglia. Chronic necrotizing inflammation was found in the placenta, fetal membranes, and one ovary. These locations showed nuclear inclusions which by in-situ-hybridization were proven to be VZV derived. This case demonstrates that in the fetal age, 'neurotropism' of VZV signifies severe destruction but not necessarily persistent inflammation of neural tissue. However, due to the inefficient fetal immune system, inflammation can go on for weeks, preferentially in non-neural tissues.

Adrenal crisis presenting as hypoglycemic coma.

An 18-month-old male infant presented with hypoglycemic coma and clinical signs of bronchopneumonia. He was suspected of suffering from septic shock. The patient progressed to irreversible multiple organ failure before the diagnosis of adrenal crisis was established. Plasma levels of ACTH and cortisol remained undetectable. Renin and aldosterone were normal. An autopsy failed to demonstrate any adrenal gland cortical tissue. Immunohistochemical staining demonstrated the presence of all pituitary hormones except ACTH, establishing the diagnosis of isolated ACTH deficiency. Intensive care clinicians should consider adrenal crisis in non-diabetic children with hypoglycemia and rapid circulatory deterioration.

Assessing gestational age from histology of fetal skin: an autopsy study of 379 fetuses.

OBJECTIVE: To develop guidelines for recognizing stages of fetal skin development to allow objective assessment of gestational age. METHODS: Three hundred seventy-nine human fetuses with known gestational ages of 12-30 weeks were examined at autopsy. Skin samples were taken from the abdomen. Two hundred fifty samples constituted a reference to establish histologic criteria from the development of skin appendages, hair, and apocrine and eccrine glands. One hundred twenty-nine additional skin samples were evaluated as a test set by the same investigators without knowledge of the condition of pregnancy or gestational age. RESULTS: The assessment of 250 skin samples allowed a description of those features that are suddenly discernible and can be used to determine gestational age as having reached or passed weeks 14, 16, 18, 20, 23, 25, and 29 or 30 (after the last menstrual period). Two examiners assessed these histologic features in a random and masked manner in the 129 skin samples of the test set. A 97% agreement with the actual gestational age of the fetus was achieved. CONCLUSION: Skin development is a continuous process, but some discrete patterns are strongly related to fetal age, are easy to recognize, and are insensitive to artifacts. In our institution, they have become indispensable in evaluating fetal and neonatal pathology.

Rescue by birth: defective placental maturation and late fetal mortality.

OBJECTIVE: To estimate the incidence and lethality of placental maturation defect, and to determine the impact of the pattern of placental dysfunction on the risk of recurrent stillbirth or maternal disease in later life. METHODS: Questionnaire and archival analysis of fetal deaths from placental dysfunction at 32-42 weeks (1975-1995 in Zurich), classified as chronic (parenchyma loss) or acute (maturation defect of the terminal chorionic villi). Population survey of 17,415 consecutive unselected singleton placentas (1994-1998 in Berlin). RESULTS: Of the 71 stillbirths, 34 were due to parenchyma loss and 37 to maturation defect. Parenchyma loss predominated in the first pregnancy (73.5% compared with 43.2%; P <.05). The risks of recurrent stillbirth and subsequent childlessness did not differ between the two groups. Eleven percent of mothers whose placenta had maturation defect had diabetes in the index pregnancy; none of the other women in the group developed diabetes over the 5-20-year observation period. In the population survey, incidence of maturation defect was 5.7%, and was associated with fetal death in 2.3% of cases. Normal placentas were associated with fetal death in 0.033%. CONCLUSION: Placental maturation defect can be a cause of fetal hypoxia. Although the risk of stillbirth is 70-fold that of a normal placenta, few affected fetuses actually die. The risk of recurrent stillbirth is tenfold above baseline and occurs mostly after 35 weeks' gestation.

Hypercalcemic-type of small cell carcinoma of the ovary: characterization of a new tumor line.

BACKGROUND: The aim of this study was to develop and characterize a mouse xenograft model for the hypercalcemic-type of small cell carcinoma of the ovary (HTSCCO). PATIENTS AND METHODS: Tumor fragments were removed from a patient and cultured in six subsequent generations of nude mice. Histology, comparative genomic hybridization (CGH), electron microscopy and serum calcium levels were investigated. RESULTS: Morphology remained the same from the primary tumor of the patient through the 6th passage in the mouse. Serum calcium levels were significantly higher in the tumor-bearing mice compared to controls. CGH of the HTSCCO did not show evidence of a close relationship to either a germ cell tumor or an epithelial ovarian cancer. CONCLUSION: Some evidence was provided that the HTSCCO is an inhomogeneous tumor that is neither related to a germ cell tumor nor to an epithelial ovarian cancer, but is a distinct tumor entity.

Explanted cryopreserved allografts: a morphological and immunohistochemical comparison between arterial allografts and allograft heart valves from infants and adults.

OBJECTIVE: Life expectancy of cryopreserved allografts implanted in infants is different from those implanted in adults. A morphological study of explanted allograft heart valves was performed to determine the mechanism of deterioration and to compare cryopreserved arterial and heart valve allografts from adult patients with those explanted from infants. METHOD: Between 1987 and 1996, 209 cryopreserved allografts were implanted: 125 valved conduits or monocusps to reconstruct the right ventricular outflow tract in congenital heart disease, 50 allograft heart valves to treat native aortic and prosthetic aortic valve endocarditis and 34 cryopreserved arterial allografts to replace mycotic aortic aneurysms or infected aortic prosthetic grafts. Two months to 8 years after implantation, 23 heart valve allografts, 11 right-sided and 12 left-sided, and four arterial allografts had to be explanted for reasons such as degeneration, recurrent infection, aneurysm formation or rupture. Besides conventional staining, immunohistochemical detection of cell populations was performed as follows: CD45RO, CD3 and CD43 for T lymphocytes, CD20 for B lymphocytes, CD68 for macrophages, protein S100 for Langerhans-cells, vimentin for fibroblasts, alpha-actin for smooth muscle cells and factor VIII for endothelial cells. RESULTS: Explanted cryopreserved allografts were all fibrotic, acellular, non-vital and without endothelial cells. The fibrous tissue was preserved. T lymphocytes, indicating rejection, were found in all right-sided allografts from the paediatric population, but only in 9% of left-sided valves explanted from adults and in one of the four of arterial allografts. Macrophages and Langerhans-cells were found only in right-sided allografts from paediatric patients. CONCLUSION: Right-sided cryopreserved allografts from a paediatric population showed ongoing cellular rejection. By contrast, there was only a weak T-cell mediated rejection to adult heart valve and arterial allografts. Therefore, similar long-term results can be expected in adult arterial and heart valve allografts, whereas longevity of right-sided heart valve allograft in the paediatric age group seems endangered by cellular rejection.

Expression pattern of cytokines in the different compartments of the feto-maternal unit under various conditions.

Concentrations of five cytokines, GM-CSF, G-CSF, IL-1, IL-6 and IL-8, were determined within five compartments under four different conditions: at the time of a Caesarean section performed between 25 and 38 weeks' gestational age in normal pregnancy without uterine contraction (n = 12), in normal pregnancy with labour already established (n = 8), in pregnancy complicated by amniotic infection (n = 11), or under the conditions of preeclampsia with fetal intrauterine dystrophy (n = 13), cytokine concentrations were determined in fetal arterial and venous blood, in amniotic fluid, and in retroplacentally obtained maternal blood and peripheral maternal blood. With dystrophy, the concentrations of GM-CSF, G-CSF and IL-1 were about 20-50% lower (P < 0.01) in the amniotic fluid, and IL-6 and IL-8 were elevated in maternal peripheral blood (P < 0.01) but not within maternal retroplacental blood. Thus, preeclampsia/intrauterine dystrophy is characterized by reduction of some cytokines within the amniotic fluid compartment and concomitant reactive augmentations of other cytokines within the maternal and fetal organism. With amniotic fluid infection, concentrations of G-CSF, IL-6 and IL-8 were elevated in all compartments (P < 0.001) but GM-CSF and IL-1 showed a significant rise only within amniotic fluid and retroplacental maternal blood (P < 0.001), a rise that was apparently not transmitted to peripheral maternal or fetal blood. Care was taken to exclude the presence of uterine contractions in the group of controls, because this condition by itself causes severe elevation of cytokine concentrations, which are pronounced within amniotic fluid.

Cardiac regression sequence: reversal of blood flow is diagnostic but not causative in an acardiac fetus.

In 1% of monozygotic twin pregnancies, one fetus is without a heart; blood circulation is maintained by an accompanying "pump" twin. Such an acardiac condition is usually diagnosed on the basis of further malformations visible by ultrasonography. We describe a monoamniotic twin pregnancy with early growth reduction in one twin. His skeleton and the shape of the body including the head were normal; however, heart, lungs and liver were absent. "Death of one twin" had thus been the diagnosis before termination of pregnancy. Studies of the blood flow in acardiac fetuses by several investigators have shown that perfusion of a heartless fetus is opposite to the normal direction and the term "twin reversed arterial perfusion sequence" has been proposed. While "reversed arterial perfusion" might be a key diagnostic element for the ultrasonographic examination of the acardiac condition, it need not necessarily be the primary cause. A lethal defect in early heart development is much more likely to be the primary event which is temporarily rescued by the presence of the accompanying "pump" twin. A term like "cardiac regression sequence" would be much better suited to describe the condition.