Ventricular remodeling: from bedside to molecule

The multiple mechanisms that bring about the decompensation of the hypertrophic remodeled myocardium are synergistic and not fully understood. Our current hypothesis is that the increased stress on the ventricle is initially offset by compensatory myocardial hypertrophy. In many instances, however, progressive ventricular dilatation and heart failure occur as a result of maladaptive hypertrophy (abnormal myosin-actin production), programmed cell death (apoptosis) and/or changes in the interstitial vasculature and collagen composition. The molecular and genetic background to these processes includes changes in myocardial gene expression, activation of the local tissue renin-angiotensin and other neurohormonal systems, increased matrix metalloproteinase activity (including collagenase), and expression of certain components of the immune system, such as TNF-alpha. Future research will hopefully provide better methods for limiting the remodeling-ventricular dilatation process by novel pharmacotherapies, gene therapy and, possibly, surgical therapy, and determine the impact of such interventions on survival.

Frequent apoptosis in human kidneys after acute renal hypoperfusion

BACKGROUND/AIMS

Apoptosis, a form of cell death characterized by DNA fragmentation and minimal inflammation, is induced by intrarenal hypoxia in rats. The objective of this study was to test whether apoptosis participates in human acute renal injury.

METHODS

We examined kidneys obtained from autopsies of 40 patients following hemodynamic compromise and from 9 controls following sudden death. Nuclear DNA fragmentation was assayed by in situ 3' end labeling (TUNEL stain) and compared to histological findings.

RESULTS

DNA fragmentation along renal tubular cells was observed in 23 (57%) of the study patients but in none of the controls (p < 0.005). Acute tubular necrosis was seen by formal histology in 27% of the patients and correlated with clinical acute renal dysfunction, while DNA fragmentation did not.

CONCLUSION

DNA fragmentation often occurs after renal hypoperfusion and does not imply renal failure. Apoptosis may participate in the adaptive response of the kidney to hypoxia.

Contemporary classification of histiocytic disorders. The WHO Committee On Histiocytic/Reticulum Cell Proliferations. Reclassification Working Group of the Histiocyte Society

Pathologists and pediatric hematologist/ oncologists of the World Health Organization's Committee on Histiocytic/Reticulum Cell Proliferations and the Reclassification Working Group of the Histiocyte Society present a classification of the histiocytic disorders that primarily affect children. Nosology, based on the lineage of lesional cells and biological behavior, is related to the ontogeny of histiocytes (macrophages and dendritic cells of the immune system). Dendritic cell-related disorders of varied biological behavior are dominated by Langerhans cell histiocytosis, but separate secondary proliferations of dendritic cells must be differentiated. Juvenile xanthogranuloma represents a disorder of dermal dendrocytes, another dendritic cell of skin. The hemophagocytic syndromes are the most common of the macrophage-related disorders of varied biological behavior. Guidelines for distinguishing the exceedingly rare malignant diseases of histiocytes from large cell lymphomas through the use of a battery of special studies are provided.

Contemporary classification of histiocytic disorders. The WHO Committee On Histiocytic/Reticulum Cell Proliferations. Reclassification Working Group of the Histiocyte Society

Pathologists and pediatric hematologist/ oncologists of the World Health Organization's Committee on Histiocytic/Reticulum Cell Proliferations and the Reclassification Working Group of the Histiocyte Society present a classification of the histiocytic disorders that primarily affect children. Nosology, based on the lineage of lesional cells and biological behavior, is related to the ontogeny of histiocytes (macrophages and dendritic cells of the immune system). Dendritic cell-related disorders of varied biological behavior are dominated by Langerhans cell histiocytosis, but separate secondary proliferations of dendritic cells must be differentiated. Juvenile xanthogranuloma represents a disorder of dermal dendrocytes, another dendritic cell of skin. The hemophagocytic syndromes are the most common of the macrophage-related disorders of varied biological behavior. Guidelines for distinguishing the exceedingly rare malignant diseases of histiocytes from large cell lymphomas through the use of a battery of special studies are provided.

Langerhans' cell granuloma confined to the bile duct

Langerhans' cell histiocytosis (LCH) of the liver is uncommon. When seen, it is part of multifocal disease and can present as biliary obstruction. We present a case of sclerosing biliary disease with a solitary LCH lesion and no evidence of systemic disease. We postulate that the LCH is a secondary phenomenon, arising against a background of a complex, familial liver disease. This case also raises the possibility that some instances of idiopathic sclerosing cholangitis may follow cryptic LCH of the bile ducts.

Renal microcirculation and tissue damage during acute ureteral obstruction in the rat: effect of saline infusion, indomethacin and radiocontrast

Radiocontrast agents and nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used for the diagnosis and treatment of renal colic. We studied their impact during unilateral acute urinary outflow obstruction upon renal microcirculation and parenchymal integrity. Laser-Doppler and ultrasonic regional flow measurements demonstrated selective decline of outer medullary blood flow by 23 +/- 2% during an acute increase of intra-pelvic pressure to 50 to 55 cm H2O (N = 28, X +/- SEM, P < 0.01). In rats preconditioned with indomethacin, this manipulation reduced medullary blood flow by 50 +/- 4% (N = 16, P < 0.01 vs. obstruction alone), with cortical and total renal blood flow declining by 18 +/- 4% and 16 +/- 2%, respectively (P < 0.01). Unilateral obstruction alone for 24 hours in intact rats resulted in injury (hemorrhage and necrosis) to the papilla and fornix (formed laterally by inner stripe and medially by the inner medulla). These changes were detected as early as 30 minutes after ureteral ligature by staining for fragmented nuclear DNA (TUNEL). Mild damage of thick ascending limbs (mTALs) was associated with substantial medial fornix injury. Indomethacin markedly increased mTAL injury in obstructed kidneys, but attenuated inner medullary damage, both in the medial border of the urinary space and at the papilla. This latter protective effect, probably mediated by the decrease in intrapelvic pressure, was blunted by concomitant intravenous fluid load. Contrast media (iothalamate) and L-NAME (N omega nitro-L-arginine methyl ester) both augmented inner stripe and inner medullary damage in hydronephrotic kidneys. In rats concomitantly subjected to radiocontrast, indomethacin and L-NAME (an acute renal failure protocol, J Clin Invest 94:1069, 1994), unilateral obstruction augmented inner stripe hypoxic damage (65 +/- 6% vs. 24 +/- 11% of mTALs in contralateral kidneys, N = 7, P < 0.01). Injury was maximal at the fornix (93 +/- 6% vs. 39 +/- 14% of mTALs in the mid-inner stripe, P < 0.01) and extended to the outer stripe and medullary rays. Thus, in the rat acute ureteral obstruction alters medullary blood flow and within 24 hours produces medullary damage in both forniceal and inner medullary locations, that is exacerbated by concomitant measures which limit medullary oxygenation. Contrast studies, forced hydration and NSAIDs for renal colic are potentially harmful and their use should be re-evaluated.

Maternal circulation in the first-trimester human placenta--myth or reality?

The classic theory of development of the uteroplacental and intervillous circulation determined that maternal blood enters the intervillous space in high-pressure streams from the early first trimester. This theory has recently been challenged and our hypothesis to be presented is that the intervillous circulation is not fully established until the end of the first trimester. Ex vivo studies of hysterectomy specimens have demonstrated that trophoblastic plugs obstruct blood flow into the intervillous space in early pregnancy and only at 12 to 13 weeks do these plugs become loose and allow for continuous maternal blood flow into the intervillous space. This concept is supported by many other experimental findings. In complicated early pregnancies the uteroplacental circulation demonstrates flow characteristics that are strikingly different from those of normal early pregnancies. In abnormal pregnancies increased flow within the intervillous space is demonstrated by color Doppler imaging. Our hypothesis supports other studies that have shown that the embryo favors an environment low in oxygen during early development and that oxygen levels in placental tissue are low in the early first trimester. The classic drawing of placental circulations is based on second- and third-trimester studies, and its applicability to the early first trimester should be revisited because we will show that new data support the hypothesis that the development of the early intervillous circulation is a progressive phenomenon.

Expression of SSEA-1 (Lewis(x)) on transitional cell carcinoma of the bladder

The expression of stage-specific embryonic antigen 1 (SSEA-1) in transitional cell carcinomas of the bladder (TCCB) has been reported to correlate with tumor grade and the likelihood of lymphatic metastases. We examined the expression of this antigen in TCCBs to evaluate if staining correlated with grade, stage, recurrence, progression and response to intravesical chemotherapy. We studied the expression of SSEA-1 in TCCBs from 74 patients by staining with two different monoclonal antibodies (Mabs), P-12 and anti-SSEA-1, to evaluate if staining correlated with grade, stage and tumor recurrence. Staining was considered as positive or negative irrespective of the intensity of staining. Extent of tumor staining was measured in quartiles of 100% (25, 50, 75 and 100). Follow-up was available in 47/74 (63%) patients and ranged from 6 months to 13 years (median 2 years). Staining with one or both Mabs was observed in 57/75 (76%) tumors. None of the grade I tumors showed > 50% staining while 26% of grade II and only 33% of grade III tumors showed staining of > 50% of cells. 21% of patients whose tumors showed staining with both Mabs were free of recurrence after resection of the primary tumor; 41% of patients with tumors staining negative with both Mabs showed no recurrence. Expression of SSEA-1 does correlate with tumor recurrence especially in grade II tumors, but the correlation is not very strong (0.05 < p < 0.1). Expression of this antigen is a weak indicator of recurrence in superficial TCCBs.

Tobacco promotion and susceptibility to tobacco use among adolescents aged 12 through 17 years in a nationally representative sample

OBJECTIVES

The purpose of this study was to examine whether youth participation in tobacco promotion campaigns is associated with susceptibility to tobacco use.

METHODS

Data were collected from telephone interviews of a national random sample of 1047 adolescents 12 to 17 years of age.

RESULTS

A proportional odds model was used to estimate the effects of age, gender, presence of a tobacco user in the household, awareness of tobacco promotions, knowledge of a young adult or adolescent friend owning a promotional item, participation in tobacco promotions, and receipt of free tobacco samples or direct mail from tobacco companies on susceptibility to tobacco use. All of the covariates, except for receiving direct mailings and knowing a young adult friend who owned a promotional item, were significantly associated with susceptibility.

CONCLUSIONS

There is a strong association between an awareness of and involvement with tobacco promotions and being susceptible to tobacco use or a user of tobacco products.

Doppler velocimetry of intraplacental fetal vessels in the second trimester: improving the prediction of pregnancy complications in high-risk patients

The purpose of our study was to assess the value of fetal intraplacental velocimetry in predicting adverse pregnancy outcome in high-risk patients. Thirty-two women with pregnancies of 22 to 25 weeks' gestation were evaluated. They had demonstrated abnormal first-trimester Doppler characteristics, yet had normal second-trimester umbilical artery velocimetry. Doppler waveforms were obtained and the ratio between intraplacental and umbilical artery resistance indices was calculated. Abnormally high ratios of intraplacental to umbilical artery resistance indices were associated with a significantly higher incidence of pregnancy complications. Among women with abnormal ratios, 17 (80%) of 21 pregnancies had later complications, whereas among those with normal ratios, only two (18%) of 11 women experienced later complications. This study demonstrates that analysis of the ratio between intraplacental and umbilical artery resistance indices in the second trimester improves the diagnostic value of Doppler velocimetry in pregnancies at risk for later obstetric complications.

AIDS-associated non-Hodgkin's lymphomas as primary and secondary AIDS diagnoses in hemophiliacs. Hemophilia Malignancy Study Group

We studied the characteristics and temporal trends of AIDS- associated non-Hodgkin's lymphoma (AIDS-NHL) in individuals with hemophilia. Prospective data were collected on 33 HIV-positive hemophiliacs with AIDS-NHL enrolled in the Hemophilia Malignancy Study (HMS), of whom 21 had primary and 12 had secondary or subsequent AIDS-defining illnesses, and analyzed for frequency and temporal trends. As compared with primary AIDS- NHL, secondary AIDS-NHL occurred at an older mean age, 37 versus 29 years (p = 0.12); at a lower mean CD4 count, 46 versus 154 (p = 0.07); after a longer period of immunosuppression (CD4 < 200/microl), 41 versus 16 months (p = 0.03); and with shorter median survival, 2 versus 7 months (p = 0.09). The presence of EBV in tumor tissue was associated with shorter survival, 1 versus 7 months (p = 0.17). Between 1981 and 1988 and 1989 and 1994, the proportion of primary AIDS diagnoses that were AIDS-NHL changed minimally, 4.6 versus 6.1%, whereas there were significant decreases in Pneumocystis carinii pneumonia (PCP, p = 0.02) and wasting (p = 0.07), and an increase in Candida (p = 0.004). These findings confirm that an increasing proportion of AIDS-NHL in hemophiliacs are occurring as secondary or later AIDS diagnoses, and they are associated with prolonged duration of immunosuppression.

Word recall versus reading speed: evidence of preserved priming in head-injured patients

This study addressed a number of issues. One purpose was to test whether memory-impaired, head-injured patients show the same pattern of memory task dissociation as reported in amnesics, that is, impaired explicit and intact implicit memory performance. The second purpose of this study was to apply the distinction between the acquisition and retention aspects of memory, which has not, as yet, been investigated adequately in the study of implicit memory. The third purpose was to evaluate the contribution of intra-item and inter-item processes in implicit memory. A group of 18 head-injured (HI) patients and 18 control subjects participated in this study. Subjects read two lists of 15 words seven times: five times consecutively, once after 20 min, and after a 1-hr delay. One list was read in the same order and the other in a different order. Acquisition and retention of the information were measured explicitly (i.e., recall of words) and implicitly (i.e., priming-reading speed). The results indicated that novel information is preserved in HI as in other amnesic patient groups, only when implicit, rather than explicit, measures of memory are used. The effect of contextual manipulation (i.e., order of presentation) was interpreted to suggest similar involvement of intra-as well as inter-memory processes in implicit memory in normal and memory-impaired subjects.

Multigate spectral Doppler velocimetry for fast assessment of intraplacental fetal circulation: a preliminary study

The aim of this preliminary study was to investigate the assessment of the intraplacental fetal circulation with a new multigate Doppler system. Doppler velocimetry of the umbilical artery is widely used for assessment of fetal well-being, but its sensitivity is too low for prediction and early detection of pathologic placental processes. Intraplacental velocimetry is more accurate and detects pathologic conditions of the placenta earlier. Color Doppler imaging of intraplacental circulations is a difficult process, and the multigate system was developed to enhance the assessment of intraplacental circulation. This study shows that the multigate system is accurate and is a successful means of fast evaluation of the intraplacental circulation.

Combined isoproterenol and epinephrine for the resuscitation of patients with cardiac asystole secondary to coronary artery disease

In summary, the use of isoproterenol as an adjuvant to epinephrine in asystolic patients may increase the likelihood of return of spontaneous circulation.

Treatment of experimental acute otitis media with ibuprofen and ampicillin

The efficacy of concurrent treatment of experimental acute otitis media with ibuprofen and ampicillin was evaluated in chinchillas with respect to clearance of the effusion and resolution of mucosal inflammation. Sixty-four chinchillas were infected with Streptococcus pneumoniae and randomly assigned to treatment with either IM ampicillin (control) or ampicillin plus ibuprofen (experimental) beginning on day 2 post inoculation. On days 3, 6, 9 and 12, 8 animals from each group were killed, effusions recovered for biochemical assay and the right middle ears prepared for histological study. Between group differences in the number of ears with effusion and effusion volume were not statistically significant. Mucosal thickness and the frequencies of ears with histopathological signs of inflammation were significantly less in the experimental group when compared to the control group. Differences in the effusion concentrations of total protease, 3 of 4 hydrolytic enzymes and free fatty acids favoring the experimental group were observed at the 6, 9 and 12 day endpoints. Also, at those times the levels of the 3 measured products of the cyclooxygenase pathway were less in the experimental group. These results suggest that the addition of ibuprofen to ampicillin for the treatment of acute otitis media decreases production of select eicosonoids, reduces mucosal inflammation and alters the course of the disease in this model of bacterial infection.

Adenovirus pneumonia in lung transplant recipients

Although Adenovirus (ADV) pneumonia has been documented in bone marrow, kidney, and liver transplantation recipients, it has only been sporadically reported in lung transplantation recipients. Among our 308 lung transplantation recipients, we identified four who developed ADV pneumonia. Formalin-fixed paraffin-embedded biopsy and autopsy specimens on all cases were studied by routine histology, immunohistochemistry (IHC), and by in situ hybridization (ISH) for evidence of ADV, and the results were correlated with the patients' clinical progression. Three of the four patients were children, and all four had a progressive and rapidly fatal course within 45 days posttransplantation. The lungs showed necrotizing bronchocentric pneumonia with tendency to spread diffusely to produce alveolar damage and organizing pneumonia. The occurrence of this rapidly fatal ADV pneumonia mainly affecting the pediatric population, early in the posttransplantation course, suggests that the infection is primary to the recipient with ADV either originating and reactivating in the donor lung or acquired from the upper respiratory tract of the recipient. The characteristic smudgy intranuclear inclusions of ADV, as well as IHC and ISH positivity, were observed in the lungs of all autopsies. Antemortem biopsy demonstration of ADV by inclusion formation, IHC, and ISH was observed in two patients. In another patient, antemortem ADV was shown only by ISH, and the recognition of inclusions was made difficult by coexistent CMV infection. Although IHC and ISH may have the potential for detecting early infection, recognition of the characteristic clinical setting with necrotizing bronchocentric pneumonia and smudgy intranuclear inclusions should alert one to the diagnosis of ADV pneumonia.

Tumor labeling in vivo using cyanine-conjugated monoclonal antibodies

Far-red-emitting cyanine fluorochromes have many properties desirable for in vivo imaging: absorption and emission at wavelengths where blood and tissue are relatively transparent, high quantum yields, and good solubility even at high molar ratios of fluorochrome to antibody. Potentially, conjugation by multiple linkages should minimize hydrolysis in vivo. We conjugated two tumor-targeting monoclonal antibodies: anti-SSEA-1 (IgM, kappa) at ratios of 1.2-35 mol dye/mol antibody and 9.2.27 (IgG2a, kappa) at 0.6-6 mol dye/mol antibody, using the cyanine fluorochromes Cy3.18, Cy5.18, and Cy5.5.18. Nude mice were inoculated using the SSEA-1-expressing MH-15 teratocarcinoma or the 9.2.27 antigen-expressing SK-MEL-2 melanoma to give tumors at several sites. Conjugated antibody was injected, and mice were imaged immediately after injection and at appropriate intervals thereafter using a standard camera lens, dissecting microscope, or endoscopes. Images were acquired using either an image-intensified video camera or cooled CCD cameras. Immediately after injection, major blood vessels and the heart, liver, and kidneys were readily visualized. After 1 day, tumor-targeting antibody conjugates were concentrated in tumors and there was little circulating conjugate; however, the bladder and kidneys were still visible. Tumors labeled by specific antibody were the most fluorescent tissues at 2 days after injection, but non-specific antibody conjugates did not concentrate in the tumors. The small intestine was weakly visualized by both specific and non-specific antibody conjugates. These data support the possibility of visualizing tumor metastasis by optical means, including currently available endoscopes.

Pathology of intestinal transplantation in children

The role of mucosal biopsy in the monitoring of pediatric intestinal allografts is analyzed. We performed a retrospective review of all biopsy, resection, and autopsy material from 22 bowel allografts in 21 patients, followed from 6 months to 3 1/4 years and treated on an immuno-suppressive regimen based on FK 506 (Tacrolimus). There were 579 biopsies, of which 35 were stomal, with two to three fragments taken at each biopsy. There were three explanted bowels and three autopsies. Stomal biopsies proved to be inappropriate for monitoring. Biopsies with three to five pieces of tissue per site, under endoscopic direction, provided the most information. Early cellular infiltrate with lymphoid activation in the absence of epithelial apoptotic figures was not considered sufficient to diagnose rejection although preceded it in most instances. At least two apoptotic figures in a gland or several single apoptotic cells in the presence of a lymphoid infiltrate with activated lymphoid follicles and prominent endothelium correlate best with clinical rejection and response to antirejection measures. Epstein-Barr viral disease is common in this population, and early, late, and noncontiguous bowel involvement can be subtle and difficult to distinguish from rejection, though without the apoptosis. Epstein-Barr virus in situ probes are essential to make the differential diagnosis and the two conditions may co-exist. Mucosal biopsy monitoring appears to be of clinical utility and is part of a program that involves clinical, endoscopic, microbiological, and morphologic assessment.

Color Doppler imaging of the uteroplacental circulation in the first trimester: value in predicting pregnancy failure or complication

OBJECTIVE

The purpose of this study was to determine the utility of color duplex Doppler sonography of the uteroplacental circulation in predicting the outcome of first-trimester gestations.

SUBJECTS AND METHODS

One hundred women with viable pregnancies of 7 to 12 weeks' gestational age were prospectively evaluated. Color Doppler imaging was used to identify the location of blood flow within the uteroplacental circulation, and spectral Doppler imaging was used to analyze waveforms obtained from the decidual spiral arteries.

RESULTS

Abnormal color Doppler findings were associated with a significantly higher prevalence of complicated pregnancies. Among women with abnormal Doppler findings, 12 (43%) of 28 pregnancies ended in miscarriage, whereas among women with normal findings only one (1.4%) of 72 women miscarried (p < .005).

CONCLUSIONS

This study indicates that abnormal blood flow patterns of the early uteroplacental circulation are associated with an increased prevalence of pregnancy complications and that color Doppler imaging may be used to predict pregnancy outcome.

The association of Epstein-Barr virus with smooth-muscle tumors occurring after organ transplantation

BACKGROUND

Epstein-Barr virus (EBV) has been associated with nasopharyngeal carcinoma, some lymphomas, and lymphoproliferative disease after organ transplantation. Many lymphoproliferative tumors that occur after transplantation are clonal, a property that classifies them as neoplastic. Clonality can be determined by analysis of the extrachromosomal circular DNA episomes produced by EBV infection.

METHODS

We describe three young children in whom smooth-muscle tumors developed 18 months to 5 1/2 years after liver transplantation with immunosuppression. We examined the tumors by microscopy and with immunohistochemical studies and molecular genetic analyses of the EBV DNA:

RESULTS

The tumors were composed of spindle cells with smooth-muscle features and resembled those described in patients with the acquired immunodeficiency syndrome. Immunohistochemical analysis was negative for EBV latent membrane protein and EBV receptor (CD21), but positive for EBV nuclear antigen 2. In situ hybridization revealed nuclear EBV sequences, and molecular genetic analysis showed the EBV genome to be clonal in all three patients.

CONCLUSIONS

Smooth-muscle tumors that developed after organ transplantation contained clonal EBV, suggesting that the virus has a role in the development of these neoplastic lesions.

Hypothesis: pathogenesis of skip areas in long-segment Hirschsprung's disease

The existence of skip areas in a subset of patients with long-segment Hirschsprung's disease (LSHD) is a rare phenomenon that poses practical and theoretical challenges. In this paper, three new cases are described and compared with preceding reports in the medical literature. In addition, an analogous distribution of ganglion cell precursors is reported in the developing large intestines of murine embryos, homozygous for the lethal spotted (ls) allele. In ls/ls embryos, which were destined to have "classic" short-segment aganglionosis coli, a transient phase was observed in which ganglion cells were present in the middle colon, but absent from the cecum and distal large intestine. This "skip area" is attributed to an extramural phase of neuroblast migration which is unique to the colon. Persistence of an abnormal pattern of neuroblast migration, similar to that observed transiently in ls/ls embryos, is invoked as an explanation for skip areas in humans with LSHD.

Role of right ventricular endomyocardial biopsy in infants and children with suspected or possible myocarditis

OBJECTIVES

To assess the diagnostic yield, sampling errors, risks, and therapeutic implications of right ventricular endomyocardial biopsy in children with suspected or possible myocarditis.

DESIGN

Retrospective study.

SETTING

Tertiary referral centre for paediatric cardiology, cardiac surgery, heart transplantation, and mechanical circulatory support.

PATIENTS AND METHODS

Review of clinical and histological findings among 63 consecutive children with possible myocarditis undergoing right ventricular endomyocardial biopsy. Review of cardiac histology at subsequent necropsy or after explantation at time of transplantation.

RESULTS

From January 1980 to December 1992, 76 biopsies were performed in 63 children (2 weeks to 18 years of age). In 41 cases, the biopsy was performed for evaluation of dilated cardiomyopathy. The median interval from onset of symptoms was one month. Eight children (20%; all with a history of less than six weeks duration) had biopsy proved myocarditis. Five of the eight children made a full recovery, including four who presented in cardiogenic shock. By contrast, only three of 33 children without evidence of myocarditis showed recovery of ventricular function. The whole heart was available for histological examination in 23 patients. Myocarditis was confirmed in one patient, and no evidence of myocarditis was found in the remaining 22 (all with negative biopsies). One procedure related death occurred in a 2 week old infant with dilated cardiomyopathy. In 22 cases, biopsy was performed for the evaluation of arrhythmia. Only one biopsy showed myocarditis.

CONCLUSIONS

The diagnostic yield of a biopsy is low in children with arrhythmias. In children presenting with profound ventricular dysfunction, a diagnosis of acute myocarditis may avoid premature consideration of transplantation as this group has an important potential for full recovery. In less critically ill patients and in those with a longer duration of symptoms the justification for biopsy is not as clear and the procedure is not without risk.

The cardiovascular sparing effect of fentanyl and atropine, administered to enflurane anesthetized dogs

Cardiovascular effects of high dose opioid together with low dose inhalant were compared with inhalant alone to determine whether opioid/inhalant techniques were less depressant on the cardiovascular system. The effects of positive pressure ventilation and increasing heart rate to a more physiological level were also studied. Cardiovascular measurements recorded during administration of enflurane at 1.3 minimum alveolar concentration (MAC; 2.89 +/- 0.02%) to spontaneously breathing dogs (time 1) and during controlled ventilation [arterial carbon dioxide tension at 40 +/- 3 mmHg (time 2)] were similar. At time 2, mixed venous oxygen tension and arterial and mixed venous carbon dioxide tensions were significantly decreased, while arterial and mixed venous pH were significantly increased compared to measurements at time 1. After administration of fentanyl to achieve plasma fentanyl concentration of 71.7 +/- 14.4 ng/mL and reduction of enflurane concentration to yield 1.3 MAC multiple (0.99 +/- 0.01%), heart rate significantly decreased, while mean arterial pressure, central venous pressure, stroke index, and systemic vascular resistance index increased compared to measurements taken at times 1 and 2. Pulmonary arterial occlusion pressure was significantly increased compared to measurements taken at time 2. After administration of atropine until heart rate was 93 +/- 5 beats/min (plasma fentanyl concentration 64.5 +/- 13.5 ng/mL) heart rate, mean arterial pressure, cardiac index, oxygen delivery index, and venous admixture increased significantly compared to values obtained at all other times.(ABSTRACT TRUNCATED AT 250 WORDS)

The normal Langerhans cell and the LCH cell

The epidermal Langerhans cell is the bone marrow-derived dendritic, antigen-presenting cell of the skin. It is characterised by a unique intracytoplasmic organelle--the Birbeck granule--and constitutively expresses class II MHC molecules and the CD1a glycoprotein. The Langerhans cell represents one of the most potent antigen-presenting cells of the body, and fulfils an important role in detecting foreign antigen entering the body through the skin and in immune surveillance. The distribution of Langerhans cells is restricted to the skin, lymph nodes, bronchial mucosa and thymus. The discovery by Nézelof in 1973 that the lesional cells in the disease then called 'Histiocytosis X' contained Birbeck granules established the close relationship between the Langerhans cell and this disease and led ultimately to the adoption of the name Langerhans cell histiocytosis to replace the older term. The LCH cell expresses the phenotype of a Langerhans cell apparently 'fixed' at an early stage of cell activation. The LCH cell is, however, functionally defective in antigen presentation, and the tissue distribution of the disease--affecting bone, skin, lymph node, lung, liver, spleen, CNS, gastro-intestinal tract and bone marrow--is quite different from the normal distribution of the Langerhans cell. Studies are now under way throughout the world to investigate the relationship between the normal Langerhans cell and the LCH cell. Specifically we need to identify whether the LCH cell is a cell arrested at a specific time in normal Langerhans cell ontogeny or if it represents a response to a biological insult to the mature Langerhans cell or its precursors.

Sudden unexpected death in childhood due to unsuspected diabetes mellitus

We report the case of an otherwise healthy 11-year-old girl who died suddenly of previously undiagnosed diabetes mellitus type I, following a 2-day minor upper respiratory infection. Insulin dependent diabetes mellitus (IDDM) is a rare cause of sudden death of apparently healthy children. This report demonstrates a recommended diagnostic pathway for IDDM from the substantiation of vesicular fatty liver to specific pancreatic histological and histochemical changes.

The histopathology of Langerhans cell histiocytosis

Selected aspects of the histopathology of Langerhans cell histiocytosis representing diagnostic difficulty and/or controversy are presented with emphasis on the composition of pathological lesions. Lesional cell phenotypes and the factors influencing variations are noted. Features of several skin-based histiocytic disorders, dermatopathic lymphadenopathy and Rosai-Dorfman disease are compared. Associations between Langerhans cell histiocytosis and juvenile xanthogranuloma and malignant disorders are considered. Observations of potential significance in the eventual elucidation of the pathogenesis of these enigmatic diseases are presented.

Recurrent and de novo giant cell hepatitis after orthotopic liver transplantation

This study examines the clinical and pathologic course of seven patients who developed giant cell hepatitis (GCH) after liver transplantation. Five of these patients also had GCH as their native liver disease and experienced a particularly aggressive course because of recurrent disease, beginning 1-21 months after transplantation. Two died and another two required hepatic retransplantation because of recurrent GCH; one of them had GCH recurrence in a second liver allograft. A remaining patient with recurrent GCH is alive 6 years after transplantation. Follow-up of the two patients who developed de novo GCH between 8 and 24 months after hepatic transplantation showed active micronodular cirrhosis in one and persistent giant cell transformation in the other at 4 years. All of the patients were serologically negative for hepatitis C virus, hepatitis B virus, and human immunodeficiency virus before transplantation. One patient became positive for hepatitis C virus after transplantation. Two patients had an associated autoimmune syndrome, which could have been accounted for by the GCH. None had a history of drug exposure. Interestingly, human papilloma virus (HPV) type 6 was detected by PCR analysis of liver tissues with GCH from one of three cases before and three of four cases after transplantation. This small series shows that GCH occurs in liver allografts, but it is uncommon. Documentation of recurrent disease in five of seven patients suggests that GCH in a subgroup of patients may be related to a transmissible agent, or that a particular recipient may injure livers in a way that elicits a giant cell reaction.

Failure of methotrexate treatment for term placenta percreta

Placenta percreta is a severe condition associated with maternal morbidity and mortality even when surgery is performed electively. Methotrexate has been suggested as a possible treatment modality for adherent placenta to avoid catastrophic surgery. The purpose of this report is to present a case where the placenta was left in situ to avoid cystectomy at the time of cesarean section, with subsequent failure of treatment with methotrexate.

Adverse interaction between clonidine and verapamil

OBJECTIVE

To report two cases of a possible adverse interaction between clonidine and verapamil resulting in atrioventricular (AV) block in both patients and severe hypotension in one patient.

CASE SUMMARIES

A 54-year-old woman with hyperaldosteronism was treated with verapamil 480 mg/d and spironolactone 100 mg/d. After the addition of a minimal dose of clonidine (0.15 mg bid), she developed complete AV block and severe hypotension, which resolved upon cessation of all medications. A 65-year-old woman was treated with extended-release verapamil 240 mg/d. After the addition of clonidine 0.15 mg bid she developed complete AV block, which resolved after all therapy was stopped.

DISCUSSION

An adverse interaction between clonidine and verapamil has not been reported previously. We describe two such cases and discuss the various mechanisms that might cause such an interaction. Clinicians should be acquainted with this possibly fatal interaction between two commonly used antihypertensive drugs.

CONCLUSIONS

Caution is recommended in combining clonidine and verapamil therapy, even in patients who do not have sinus or AV node dysfunction. The two drugs may act synergistically on both the AV node and the peripheral circulation.

Acute myocarditis. Rapid diagnosis by PCR in children

BACKGROUND

The diagnosis of viral myocarditis remains difficult and generally depends on clinical and histological criteria. Viral cultures and serology are often unrewarding, with low yields. The purpose of this study was to analyze the usefulness of polymerase chain reaction (PCR) in the rapid diagnosis of acute myocarditis in children.

METHODS AND RESULTS

PCR was used to analyze 38 myocardial tissue samples from 34 patients with suspected acute viral myocarditis and 17 control patients with congenital heart disease (14) or hypertrophic cardiomyopathy (3). Myocardial samples were obtained at the time of right ventricular biopsy (13 samples), from explanted hearts (18 samples) at transplantation, and from cardiac autopsy specimens (24 samples) and were evaluated for the presence of enterovirus, cytomegalovirus (CMV), adenovirus, and herpes simplex virus (HSV) using PCR primers designed to consensus and unique sequences of these viral genomes. Blood also was obtained at the time of biopsy (11) or transplant (18). In 26 of 38 myocardial samples (68%), viral genome was detected by PCR (15 adenoviral, 8 enteroviral, 2 HSV, 1 CMV), whereas all control myocardial samples and blood samples were negative. Four patients had positive viral cultures, and these matched the PCR findings. Disagreement with histopathology occurred in 13 of 26 PCR-positive specimens, usually associated with adenovirus.

CONCLUSIONS

PCR offers a rapid, sensitive diagnostic method for myocardial viral infection. While enterovirus is an important etiological agent, adenovirus was more prevalent in this series and should be evaluated when etiology is sought. PCR used in conjunction with standard endomyocardial biopsy appears to enhance the likelihood of detecting viral genome in the myocardium of patients with clinical evidence of myocarditis.

Overexpression of the oncoprotein p53 in primary hepatic tumors of childhood does not correlate with gene mutations

High levels of expression of the p53 protein and gene mutations have been described in adult hepatocellular carcinomas. It has been postulated that specific mutations in exon 7 may be caused by aflatoxin exposure. To determine whether p53 mutations occur in childhood liver cancer unassociated with aflatoxin exposure or hepatitis B virus (HBV) infection, we have analyzed three histologically distinct tumor types. Two techniques were used to access p53 in the tumors: (1) expression studies of the p53 protein were performed using the polyclonal antibody CM1 and immunohistochemistry, and (2) DNA sequencing was performed. p53 Protein was detectable by immunohistochemistry in 10 of 15 hepatoblastomas, six of nine hepatocellular carcinomas, and one of one embryonal sarcomas. Solid phase single-stranded DNA sequencing across exons 5 through 9 showed normal sequence in all cases. These results indicate that p53 is overexpressed in a majority of childhood liver cancers, but this abnormal p53 expression does not seem to be caused by mutations in the p53 gene.

The A1 pulley in rheumatoid flexor tenosynovectomy. To retain or divide?

We report a detailed comparative evaluation of flexor tenosynovectomy in 55 fingers in which the A1 pulley was divided and 45 fingers in which the A1 pulley was retained. The metacarpophalangeal joint subluxed volarly in 49% when the A1 pulley was divided, compared to 11% when the pulley was preserved. Bowstringing occurred in 7% and only when the A1 pulley was divided. Ulnar deviation was 7 degrees worse when the pulley was divided. Active range of movement was limited in both groups. It was 11 degrees less when the A1 pulley was divided.