Complete 1H, 13C, and 15N assignments and secondary structure of the GTPase activating domain of Gs

Complete 1H, 13C, and 15N assignments for backbone and side-chain atoms of the 145 residue GTPase activating domain of Gs are presented. The combination of gradient-enhanced versions of the HNCACB and CBCA(CO)NNH pulse sequences provided enough information to obtain sequential backbone assignments for residues 2-145 of the polypeptide, as well as assignments of asparagine and glutamine side-chain amides. HBHA(CO)NNH, HCCH-TOCSY, and 13C/15N NOESY-HSQC experiments yielded side-chain 1H and 13C assignments. Chemical shift data and 15N NOESY-HSQC experiments provided information on the secondary structure of the domain, which is similar to that observed in the cognate domain in transducin, a related G protein. The functionally essential C-terminal 15 residues are disordered in solution. These assignments provide a basis for determining the solution structure of the domain.

Increased expression of human leukocyte antigen-DR on pulmonary macrophages in bronchopulmonary dysplasia

We used an immunoperoxidase method to examine the expression of the immune activation marker HLA-DR on pulmonary tissue obtained at autopsy from 14 patients dying of bronchopulmonary dysplasia. Controls consisted of 16 age-matched, sex-matched children dying of noncardiac, nonrespiratory, noninfectious illnesses or as a result of motor vehicle accidents. We did not observe aberrant expression of HLA-DR on pulmonary endothelial cells. Positive staining appeared exclusively on macrophages. We quantitated the expression of antigen by counting the number of positive macrophages and total macrophages/monocytes per high power field. Bronchopulmonary dysplasia patients displayed significantly greater numbers of both positive and total macrophages compared with the control group (p < 0.05). The percent positive macrophages also was significantly higher in the bronchopulmonary dysplasia patients (p < 0.005). We also examined a group of patients dying with infant respiratory distress syndrome. There was no significant difference in number of total macrophages in this group compared with age-matched controls.

Nitrofen-induced congenital diaphragmatic defects in CD1 mice

In previous clinical reports, we have documented the association of several morphologic changes with congenital diaphragmatic hernia or, perhaps more appropriately termed, congenital diaphragmatic defect (CDD). These anomalies include decreased cardiac mass with left ventricular hypoplasia in infants with left-sided CDDs (Siebert et al., '84), enlarged, asymmetric chests (Siebert and Benjamin, '87), and extrathoracic anomalies (Benjamin et al., '88), including urinary tract anomalies and elevated kidney weights in otherwise normal kidneys (Glick et al., '90; Siebert et al., '90). Hypoplastic lungs and hearts and enlarged chests are thought to result from the herniation of abdominal viscera into the thoracic cavity, but for the renal abnormalities, pathogenesis is unclear. The findings are intriguing, for they could mirror unrecognized developmental relationships between the diaphragm, lung, heart, and kidney. In order to further examine these issues and to test the applicability of experimentally produced CDDs to human disease, we administered nitrofen (2,4-dichlorophenyl-p-nitrophenyl ether), an herbicide known to produce diaphragmatic defects in rodents, to time-mated CD1 mice by gavage feeding on gestational days 8 and 9. Dosages were 200 (low dose) or 500 (high dose) mg/kg body weight, and fetuses were studied on gestational day 18. Diaphragmatic defects occurred in a dose-response fashion: 0% (0/48) control or sham-fed, 5% (5/104) in the low-dose group, and 25% (19/75) in the high-dose group. Several fetuses with cleft palate, renal agenesis, exencephaly/encephalocele, and/or Di-George sequence were noted at the high dose, the latter a previously undescribed finding. Diaphragmatic defects were primarily right sided and only associated with herniation of abdominal viscera in animals exposed to 500 mg/kg.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship between epidemiologic risk factors and clinicopathologic findings in the sudden infant death syndrome

The risk of sudden infant death syndrome (SIDS) is said to be enhanced by factors such as prematurity, low birth weight, and perinatal distress. The significance of risk factors for SIDS research was questioned because the majority of SIDS victims seem to lack them. Therefore, postmortem records of 1144 infants who died suddenly and unexpectedly in King County, Washington, over a 25-year period were studied. Deaths were classified as "explained" if a cause was apparent, "classic" SIDS if the history and autopsy were unrevealing or, where the diagnosis of SIDS was doubtful, as "probable" or "possible" SIDS. The infants' birth certificates were compared with those of 3647 infants born during a similar period. Seventy-nine deaths (7%) were explained. The 1065 previously certified as SIDS were reclassified classic SIDS (82%), probable SIDS (13%), and possible SIDS (5%). Low birth weight, small size for gestational age, prematurity, and low 5-minute Apgar scores each form a "continuum"; the possible-SIDS group had the highest proportion of such infants, followed by the probable- and classic-SIDS groups, which exhibit extensive overlap with the control population. A 5-minute Apgar score of less than 7 and delayed postnatal growth rate are not risk factors for classic SIDS. Risk factors are more prevalent in SIDS infants where the diagnosis may be doubtful. The great majority of SIDS victims possess fewer risk factors. To avoid the bias of confounding variables, SIDS research should focus on as "pure" a SIDS population as is possible.

Multicystic pancreatic hamartoma: a distinctive lesion with immunohistochemical and ultrastructural study

A multicystic pancreatic hamartoma is reported in a 20-month-old female who presented with abdominal pain and distention. This appears to be a distinctive lesion not previously characterized in the English language literature. The 9-cm mass consisted of large, irregular lobules of well-formed pancreatic acini admixed with fibrous tissue and fat. Cystically dilated ducts of variable caliber lined by benign epithelium were present. Endocrine cell islets were not evident. Immunohistochemistry and ultrastructural examination illustrated insulin-producing cells diffusely throughout the exocrine tissue as single cells or in small groups. Cells producing other pancreatic hormones were markedly decreased when compared with an age-matched control pancreas and were similarly dispersed. The patient was alive and well without tumor 9 months later. This entity may provide an unusual opportunity for insight into pancreatic organogenesis and pancreatic cellular differentiation.

Appendiceal US scans: histologic correlation

High-resolution in vitro ultrasonography (US) of 20 surgical appendiceal specimens was performed to compare appearances of appendiceal tissue at US with corresponding histologic features. With an articulated-arm system and micropositioner, precise spatial correlation was achieved. As elsewhere in the gastrointestinal tract, five distinct echo layers were observed. Normal and inflamed specimens demonstrated these layers, but the architecture became disorganized and indistinct in cases of appendicitis. Three measurements were made for each specimen: (a) overall cross-sectional diameter, including the lumen, (b) thickness of the submucosal echo layer, and (c) the combined thickness of both walls, excluding the lumen. For the inflamed specimens, a substantial increase in the thickness of the summed wall measurements was found. Wall US appearance alone may be misleading in differentiation of normal and abnormal appendices.

Mushroom poisoning in infants and children: the Amanita pantherina/muscaria group

The clinical features and management of nine cases of mushroom poisoning due to Amanita pantherina (eight cases) and Amanita muscaria (one case) admitted to a children's hospital are described. Most ingestions were in the toddler age group with males being more frequently involved. Symptoms occurred between 30-180 min with the onset of central nervous system depression, ataxia, waxing and waning obtundation, hallucinations, intermittent hysteria or hyperkinetic behavior. Vomiting was rare. Seizures or myoclonic twitching occurred in 4/9 patients, but was controlled with standard anticonvulsant therapy. No other anticholinergic or cholinergic signs were prominent. Recovery was rapid and complete in all patients.

Results of treatment of malignant germ cell tumors in 93 children: a report from the Childrens Cancer Study Group

We report treatment results in 93 children entered on study from 1978 to 1984 with malignant germ cell tumors (MGCTs), excluding dysgerminoma and tumors of the testis or brain. The estimated 4-year survival and event-free survival (EFS) for all 93 patients were 54% and 49%, respectively. For 30 children with ovarian tumors, the estimated 4-year survival was 67% and EFS was 63%. For 63 children with nongonadal tumors, survival and EFS were 48% and 42%, respectively. The comparison of EFS between ovarian and nongonadal tumors was significant at P = .03. The treatment plan included a second-look surgical procedure after 18 weeks of chemotherapy. Over half of 36 patients evaluated as having a residual mass present immediately before second-look surgery had no malignant tumor after review of surgical specimens. Age greater than 11 years at diagnosis, incomplete removal of tumor at first surgery, and more than one structure or organ involved at diagnosis increased the risk for adverse event. The histologic subtype of the primary tumor was not related to outcome. Diagnosis was verified by independent pathologic review, and treatment was uniform. Seventeen percent of all registered patients (21 of 127) were excluded because of ineligible pathologic diagnoses; sixty percent (13 of 21) were immature teratomas.

Aberrant cytoplasmic expression of proliferating cell nuclear antigen in Hodgkin's disease

During a study using a monoclonal antibody directed against proliferating cell nuclear antigen (PCNA) to assess the proliferative activity of tumors, it was noted that the cytoplasm of Reed-Sternberg (RS) cells and variants of these cells in cases of Hodgkin's disease reacted very positively. This aberrant expression of PCNA has not been observed in any other tumor or in cells from normal tissues. The biological significance of this observation is currently unknown, but it may have diagnostic utility in detecting and identifying RS cells.

Proliferating cell nuclear antigen (PCNA) and pediatric tumors: assessment of proliferative activity

Monoclonal antibodies to proliferating cell nuclear antigen (PCNA) were used to detect proliferating cells in pediatric tumors fixed in Carnoy's solution. The percentage of staining cells was quantified using image analysis and compared to the S + G2M phase fraction as determined by flow cytometry. Although there was a general correlation between these indices of cellular proliferation, some variation was noted between tumor systems as well as within a specific tumor type. In some cases this variation was easily explicable by the morphologic findings (e.g., tumor heterogeneity and sampling differences, stromal cell proliferation, necrosis, extramedullary hematopoiesis), whereas in others it appeared to be an intrinsic property of the cell line. It is concluded that PCNA immunostaining is a useful and reproducible method of assessing one aspect of cellular proliferative activity and especially of addressing the questions, "which cells are dividing and where?" It has some advantages over flow cytometry in that it maintains tissue integrity and morphologic relationships.

Bronchioloalveolar carcinoma of the lung and congenital cystic adenomatoid malformation

A case of bronchioloalveolar carcinoma of the lung is described in a 19-year-old man who had had a lobectomy in infancy, for removal of a congenital cystic adenomatoid malformation. It is suggested that congenital cystic adenomatoid malformation may predispose a patient to development of epithelial malignancies of the lung, whereas mesenchymal hamartomas usually are associated with nonepithelial neoplasms.

The role of timing of high-dose cytosine arabinoside intensification and of maintenance therapy in the treatment of children with acute nonlymphocytic leukemia

The Children's Cancer Study Group instituted a pilot study to investigate the use of high doses of cytosine arabinoside (AraC) in the intensification phase of treatment for acute nonlymphocytic leukemia (ANLL). Patients achieving remission and not eligible for allogeneic bone marrow transplantation were treated with four doses of high-dose AraC and L-asparaginase. These drugs were repeated either on or after 28 days (q28 days), after recovery of hematologic parameters (for the first 49 patients entered onto this trial); or after 7 days (q7 days), despite dropping blood counts (for the last 53 patients enrolled). After completing an additional 3 months of intensification therapy, patients were then allocated by physician choice to either discontinue therapy or receive 18 28-day cycles of maintenance therapy, including the daily administration of 6-thioguanine. Despite three deaths associated with the toxicity of the aggressive (q7 days) AraC timing, patients receiving this approach demonstrated equal or better disease-free survival from the end of induction (55% versus 42% actuarially at 3 years [P = 0.52]). Maintenance therapy appeared to play no role in improving outcome for people who received the aggressive timing of AraC cycles. Fifty-nine percent were alive disease free actuarially at 3 years from the decision to not give maintenance therapy (n = 27) compared with 62% for those receiving maintenance therapy (n = 16; P = 0.49). On the other hand, patients who received the less aggressive AraC intensification timing (q28 days) had an improved survival rate if maintenance therapy was administered (n = 17) (65% versus 39% for patients not receiving maintenance therapy [n = 24] at 3 years [P = 0.07]). Maintenance therapy therefore may not improve outcome in patients receiving aggressive timing of high-dose AraC but may be important in less intensive postremission regimens in childhood ANLL.

Urinary tract anomalies associated with congenital diaphragmatic defects

Anomalies of the urinary tract occur in some 13-27% of infants with congenital posterolateral diaphragmatic defect (CDD) and are often severe (renal agenesis, dysplasia, hypoplasia, or hydronephrosis). To test the hypothesis that urinary and diaphragmatic anomalies share elements of pathogenesis, we reviewed 60 autopsy cases of CDD studied at our institution. Sixteen patients (27%) manifested anomalies of the urinary tract: 12 had markedly altered kidneys, 8 of which were unilateral and ipsilateral to the diaphragmatic defect. Among 27 patients free of gross urinary tract anomalies, kidney weights formed a skewed distribution, with most values above published norms for body weight; by analysis of covariance, kidney weight (as a function of body weight) was significantly greater in CDD than in a control population of infants free of chronic illnesses and congenital anomalies who died suddenly and unexpectedly. Differences in glomerular number and diameter could not be identified between the latter groups. In 71% of patients with isolated left CDD, the left kidney was heavier than the right, a reversal of the usual condition in infancy. These findings demonstrate that both marked and subtle changes of the urinary tract in CDD are generally ipsilateral to the diaphragmatic defect and suggest that the pathogenetic mechanisms responsible for urinary and diaphragmatic anomalies may overlap topographically. Aberrant morphogenesis within a developmental field or fields is one explanation for this.

Pathophysiology of congenital diaphragmatic hernia: I. Renal enlargement suggests feedback modulation by pulmonary derived renotropins--a unifying hypothesis to explain pulmonary hypoplasia, polyhydramnios, and renal enlargement in the fetus/newborn with congenital diaphragmatic hernia

Survival of newborns with congenital diaphragmatic hernia (CDH) is largely dependent on the severity of pulmonary hypoplasia (PH) present at birth. Intrathoracic compression by the herniated abdominal viscera is thought to be the primary factor involved in the pathogenesis of the PH in CDH. Humoral and/or amniotic pulmonary growth factors (PGF) have been hypothesized to play a role in normal fetal pulmonary development and may be involved in the pathogenesis of CDH as well. The hypothesis of this paper is that growth of the fetal lung is stimulated by a PGF produced by the kidneys, which is modulated by a feedback signal from the lungs, a pulmonary derived renotropin (PDR). In the fetus with CDH, the lungs may be unable to respond to PGF due to compression by the herniated abdominal viscera. Theoretically, PH associated with CDH would maximally stimulate this feedback loop to release more PDR, resulting in continual stimulation of the kidneys and renal enlargement. If such a scheme plays a role in the in utero pathophysiology of CDH, then newborns with CDH should have enlarged kidneys. To investigate this hypothesis, we reviewed 30 autopsy cases of newborns with CDH and analyzed their kidney weights versus body weights, using historical data as control. Kidney weights in CDH cases were greater than the control population in 77% of the cases; 57% of kidney weights were more than one standard deviation above control values. Adjusted group mean kidney weights were 29.8 g (+/- 1.0 SE) in CDH cases and 25.9 g (+/- 1.5 SE) in the control population (P less than .04). These data support our hypothesis and demonstrate that in newborns with CDH and morphologically normal kidneys, there is significant renal enlargement associated with CDH. The presumed mechanism of this renal enlargement, as well as its relationship to normal and aberrant pulmonary growth and regulation are discussed. If such a selective PGF exists, its therapeutic implications for fetuses and newborns with PH are considerable.

C-reactive protein and prealbumin in suspected sudden infant death syndrome

This study investigated the levels of C-reactive protein (CRP) and prealbumin in 87 infants suspected of dying from sudden infant death syndrome (SIDS). These proteins change rapidly, within 24 hr, in patients who have an acute phase response, especially a response resulting from bacterial infection. In addition, prealbumin is sensitive to a recent reduction of protein or calorie intake. Eighty patients were determined to have typical SIDS. Only four of these had a minimal increase in CRP (0.8-2 mg/dl), and in none could an explanation be found. Seven patients were uncovered who had a significant infection, four of whom had prominent CRP elevations. Prealbumin was not decreased in the SIDS population. We conclude that there is no evidence that the acute inflammatory response is activated in infants dying of SIDS. An elevation of CRP above 2 mg/dl should prompt additional studies to find the cause. There is also no evidence of a recent, significant decrease in nutrition in these patients.

Congenital monocytic leukemia: report of a case with cutaneous involvement, and review of the literature

Congenital leukemia is a rare disease that can become manifest soon after birth. Cutaneous involvement consists of red, brown, or purple papules and nodules, and confluent areas of purpura. The diagnosis is established by the presence of leukemic cells in biopsy specimens of bone marrow and involved skin, and by immunocytochemical characterization of these cells. We report a case of congenital monocytic leukemia with a normal karyotype, whose disease underwent temporary spontaneous regression.

Ebstein's anomaly and extracardiac defects

Ebstein's anomaly of the tricuspid valve occurs as an isolated defect with other forms of congenital heart disease such as transposition of the great arteries or tetralogy of Fallot or, rarely, in association with extracardiac malformations. Because so little is known about this latter group, we studied four cases clinically, at autopsy, and by means of a retrospective chart review. Major extracardiac changes most often involved the craniofacial region, central nervous system, and limbs. Karyotypes were normal, and no distinctive syndromes or anatomic patterns were identified. Since the timing of Ebstein's anomaly is quite precise, ascertainment of such cases on the basis of cardiac morphology may enhance the understanding of etiology and pathogenesis. Both causes and mechanisms may well be diverse, for the clinical histories and anatomic findings in present and previously reported cases vary considerably. Isolated Ebstein's anomaly may develop from topographically and temporally localized damage. Ebstein's anomaly with extracardiac defects may involve damage during a longer, and perhaps earlier, period.

Laboratory tests and nutritional assessment. Protein-energy status

1. There is no one definitive laboratory test, group of tests, or indices that are satisfactory for the assessment of protein-calorie status. 2. Clinical evaluation remains the simplest, most widely available, most reproducible, and wisest method. It is satisfactory for the majority of clinical situations. 3. The laboratory should be used selectively and to complement clinical evaluation. Routine testing must be relegated to research protocols. 4. Always include some assessment of inflammation (for example, C-reactive protein, erythrosedimentation rate [ESR]), because its presence affects the interpretation of all the other tests. 5. The pathophysiologic effects of the underlying disease, especially in hospitalized patients, will affect the interpretation of every one of the laboratory tests. 6. Nutritional status often impacts more on the interpretation of commonly performed laboratory tests than laboratory tests impact on the assessment of nutrition.

Acute nonlymphocytic leukemias of childhood. Inter-observer variability and problems in the use of the FAB classification

The French-American-British (FAB) classification system and some recent modifications were applied to 486 children with a diagnosis of acute nonlymphocytic leukemia (ANLL) to determine the distribution of the subtypes in children, to document the extent of inter-observer variation in assigning subtypes, and to examine the reasons for the differences. The distribution of FAB subtypes of childhood ANLL was similar to that reported for adults. In the initial year of the study, the inter-observer concurrence between the institutional diagnosis and the reviewing pathologists was 50%, but in the more recent years, concurrence between institutions and the review pathologist has approached 80%, averaging around 73% for the entire study. Many problems remain to be solved with this classification system, including the imprecision in wording, the subjectiveness of the interpretation, errors due to the random distribution of cells, and the current lack of evidence that certain FAB subtypes, such as M1 and M2, differ significantly in terms of biological behavior and prognosis.