Cecal volvulus in the Cornelia de Lange syndrome

Cornelia de Lange syndrome is a congenital malformation characterized by severe growth failure, mental retardation, and multiple physical anomalies. A variety of gastrointestinal anomalies have been described, including malrotation, colonic duplication, and nonfixation of the colon. Two patients with Cornelia de Lange syndrome presented to our institution with acute distal bowel obstruction. In both cases, emergency laparotomy showed cecal volvulus with necrosis of the terminal ileum, cecum, and ascending colon, secondary to nonfixation of the colon. Resection and an end-ileostomy were performed and later successfully reversed in both patients. Intestinal obstruction is a known cause of death in these children, and nonfixation of the colon has been identified during autopsy. Parents of children with Cornelia de Lange syndrome should be counseled as to the possibility of bowel obstruction resulting from cecal volvulus. This awareness may lead to earlier identification and treatment of this potentially lethal gastrointestinal tract anomaly.

Massive chylothorax associated with lymphangiomatosis of the bone

Chylothorax in the absence of tumor or trauma is uncommon. Lymphangiomatosis of the bone, although extremely rare, has been associated with chylothorax. The authors describe the case of a 12-year-old boy who presented with a symptomatic left chylothorax associated with lymphangiomatosis of the ribs, scapula, and clavicle. Despite tube thoracostomies and the initiation of total parenteral nutrition, massive losses of chyle persisted, resulting in hypoproteinemia and severe lymphopenia. Control of the chylothorax was achieved by a parietal pleurectomy and application of fibrin glue (Tisseel). In the literature there are 16 cases of chylothorax associated with lymphangiomatosis of the bone. Their presentation, treatment, and outcome are reviewed. Conservative treatments such as dietary manipulations or thoracenteses were rarely successful. Thoracotomy with parietal pleurectomy on the side of the effusion is usually effective in controlling the chylothorax. Lymphangiomatosis should be considered a diagnostic possibility for any child who presents with a chylothorax.

Cutaneous malignant melanoma in Australia, 1989

OBJECTIVE

To describe the characteristics of cutaneous malignant melanoma in Australians in 1989. DESIGN AND DATA: Descriptive analysis of all invasive melanomas reported to State or Territory cancer registries in 1989.

MAIN OUTCOME MEASURES

The age, sex and State or Territory of residence of affected individuals, and the topography, morphology and thickness of the melanoma.

RESULTS

The age-standardised incidence rates of melanoma were 30.2 and 23.9 per 100,000 males and females respectively; the highest rates were observed for the male trunk (11.7 per 100,000) and female lower limbs (8.8 per 100,000); the most commonly specified morphology was superficial spreading melanoma, followed by nodular melanoma and lentigo malignant melanoma. Fifty-two per cent of melanomas of known thickness were thinner than 0.76 mm, with females having proportionally more thin melanomas than males, and males having twice the rate of melanomas thicker than 3 mm. Melanoma rates in northern latitudes were approximately double those further south.

CONCLUSIONS

Distinct patterns of melanoma incidence by latitude and body site confirm the role of sunlight exposure in melanoma aetiology. Females often have thinner melanomas than males, which is reflected in their better prognosis. People living closer to the equator more often have level 1 (in situ) and thin invasive melanoma, probably related to increased awareness of melanoma risk with decreasing latitude. The collection of melanoma data would be improved if pathologists' reports routinely included melanoma site, morphology, level and thickness. All registries should collect data on level 1 melanomas to help evaluate early melanoma detection programs and to continue surveillance of the Australian skin cancer epidemic.

The spectrum of beta thalassaemia mutations in the UAE national population

The beta thalassaemia alleles in 50 beta thalassaemia heterozygotes originating from many parts of the United Arab Emirates (UAE) have been characterised using the allele specific priming technique of the polymerase chain reaction (PCR). The IVSI-5 (G-->C) mutation was found to be present in 66%, while six other alleles occurred at the much lower frequencies of 2% to 8%. These were codon 8/9 (+G), IVSI-1, 3' end (-25 bp), codon 5 (-CT), IVSII-1 (G-->A), codon 30 (G-->C), and codon 15 (G-->A). The mutation types and percentages are compared with other Mediterranean Arab countries and neighbouring areas. It is proposed that IVSI-5 and other Asian Indian mutations were introduced into the UAE by population migration from the region previously known as Baluchistan. These findings should be useful for genetic counselling and the development of a first trimester prenatal diagnosis programme based on direct detection of mutations in the UAE.

Routine inguinal hernia repair in the pediatric population: is office follow-up necessary?

Routine inguinal hernia repair in the pediatric population has a low complication rate. Very few complications are identified at follow-up, which brings into question the necessity of the traditional postoperative visit. A retrospective review of patients who had undergone a routine inguinal hernia repair in 1991 at our institution was done in order to determine our current follow-up practices and complication rate. To determine the perceived necessity for the follow-up visit, parents were given a short telephone questionnaire. Of 175 eligible patients, questionnaires were completed on 145. Of these 145 patients, 77 were seen in follow-up by the pediatric surgeon only, 43 by the family doctor only, 12 were seen by both, and 13 patients had no physician follow-up. The sole complication was a stitch abscess (complication rate 0.7%). Results of the questionnaire showed that 90% of parents felt the follow-up visit was "helpful," 80% felt it was "necessary," and 35% would have been satisfied with telephone follow-up. The main purpose of the postoperative visit appears to be parental reassurance. Careful preoperative and postoperative instruction and reassurance may be sufficient in a significant number of cases.

Ankle fracture is associated with prolonged venous dysfunction

Leg swelling is a significant problem following ankle fracture. Venous pump function and femoral and popliteal venous patency were assessed prospectively in 26 patients with ankle fractures requiring open reduction, internal fixation and immobilization in plaster. Functional venous volume, venous filling index (VFI), ejection volume fraction (EVF) and residual volume fraction (RVF) were measured using air plethysmography at 5 days and at 6, 12 and 18 weeks after fracture. The uninjured leg was used as a control. Popliteal and femoral venous patency was determined using duplex ultrasonography. No patient developed deep vein thrombosis during the study. At 5 days after fracture there was a significant reduction in mean(s.d.) EVF, 18.2(12.1) versus 55.9(19.5) per cent, and increase in RVF, 87.0(14.3) versus 42.5(22.2) per cent (both P < 0.001). Analogous values were similar at 6 weeks, EVF 28.5(21.2) versus 55.6(21.9) per cent, RVF 82.2(16.8) versus 48.5(23.8) per cent (both P < 0.001), and at 12 weeks, EVF 39.1(16.0) versus 60.3(14.9) per cent, RVF 64.7(18.8) versus 38.8(13.2) per cent (both P < 0.001). However, by 18 weeks there was no significant difference in venous function between fractured and control limbs. It is concluded that there is a significant and prolonged impairment in venous pump function following ankle fracture.

Non-Rayleigh first-order statistics of ultrasonic backscatter from normal myocardium

Historically, it has been assumed that the first-order envelope statistics of ultrasonic backscatter from myocardium are best described by the Rayleigh probability distribution function (PDF); however, few studies have tested this assumption. This study compares the ability of five PDFs, including the Rayleigh, to describe high-frequency (5-15 MHz) ultrasonic backscatter from in vivo canine myocardium and in vitro human myocardium. The PDFs used have all been previously proposed as descriptions of backscatter from parenchymal tissue or other random media. In this study goodness-of-fit testing of backscatter recorded at several frequencies and insonification angles shows that only in a minority of cases is the envelope. Rayleigh-distributed. In most cases, the K distribution provides the best fit. In addition, computer simulation shows that sparse Poisson scattering can produce K-distributed backscatter. Scattering of this type may contribute to the observed non-Rayleigh character of myocardial backscatter. We conclude that the Rayleigh distribution is not an adequate description of backscatter from myocardium. Non-Rayleigh distributions may offer an additional approach to myocardial tissue characterization.

A complex chromosome rearrangement forms the BCR-ABL fusion gene in leukemic cells with a normal karyotype

Chromosome in situ hybridization studies showed that the normal karyotype of leukemic cells from a patient with Ph1-negative, BCR-positive chronic myeloid leukemia (CML) concealed a complex t(9;22;20)(q34;q11;p13). The close association of 5'-BCR and 3'-ABL was demonstrated by field inversion gel electrophoresis, and in situ hybridization showed that BCR-ABL was located on the short arm of chromosome 20. Our findings further indicate that chromosome rearrangement is the cause of BCR-ABL gene fusion in leukemic cells that show a normal karyotype. Results from in situ hybridization studies were consistent with formation of the t(9;22;20) by a two step chromosomal rearrangement, but field inversion gel electrophoresis results indicated a more complex rearrangement.

Human rib bone marrow mononuclear cells spontaneously synthesize and secrete IgE in vitro

We have examined spontaneous secretion of IgE by human rib bone marrow mononuclear cells (MNC). Bone marrow MNC from nine out of 12 rib specimens synthesized and secreted substantial amounts of IgE during 14 days of in vitro culture. The 14-day supernatants from these bone marrow MNC contained a mean of 2589 pg/ml of IgE (n = 12) with a maximum production of 15,408 pg/ml of IgE compared with small amounts of IgE (80-200 pg/ml) produced by similarly cultured normal and inflammatory bowel disease intestinal lamina propria MNC. Using two rib specimens, time-course studies revealed spontaneous secretion of IgE to be minimal during the first 2 days of culture (152 pg/ml), followed by a steady increase between days 4 (517 pg/ml) and 14 (3588 pg/ml). The addition of pokeweed mitogen resulted in 72% suppression of spontaneous IgE production by bone marrow MNC. The bone marrow MNC isolated from the ribs consisted of 22% Leu12+ (B) cells of which 3.2% were surface IgE positive. Staining for cytoplasmic immunoglobulin revealed 1% of the bone marrow MNC to be cytoplasmic IgE+. The presence of IgE-bearing and IgE-secreting MNC in human bone marrow is consistent with the observation that allergen-specific IgE-mediated hypersensitivity is adoptively transferred by human bone marrow transplantation and demonstrates the usefulness of human bone marrow MNC for examination of IgE secretory and regulatory events.

Intravascular ultrasound as a guiding modality for mechanical atherectomy and laser ablation

One of the most compelling practical applications for intravascular ultrasound imaging is in enhancing the safety and efficacy of the second-generation catheter devices designed to ablate or remove plaque. Initial studies have shown that intravascular ultrasound is well suited to demonstrate the amount of atheroma present in a vessel, and the distribution within the vessel wall at any given point. Further clinical studies are required to determine whether more complete debulking of atheroma, guided by ultrasound imaging, has a favorable impact in reducing the rates of acute closure and restenosis following the procedure.

Bronchopulmonary dysplasia: a radiographic and clinical review of 20 patients

This paper reviews the radiological features of 20 infants with bronchopulmonary dysplasia, with particular emphasis on the early radiological findings in these infants, the clinical findings and radiological progression. Of 20 infants, eight had idiopathic respiratory distress in the first week of life, two infants had early radiological abnormalities other than idiopathic respiratory distress and 10 infants had normal initial chest radiographs. The complicating features included lower respiratory infections (88%), patent ductus arteriosus (40%) and areas of atelectasis (40%). Areas of atelectasis were more common in infants with an initially normal chest radiograph than in those with idiopathic respiratory distress syndrome (p = 0.015). Mortality from severe bronchopulmonary dysplasia was 70% in this series.

Physiological factors in infantry operations

Male infantry soldiers (n = 34) were studied before, during, and after a 5-day simulated combat exercise. During the exercise, subjects were rated on their field performance by senior infantry non-commissioned officers. Prior to the exercise, direct measures of body composition and maximal oxygen uptake were obtained. Before and after the exercise the Army Physical Fitness Test and various measures of anaerobic capacity (Wingate and Thorstensson tests) and muscular strength (isometric and isokinetic) were obtained. Results showed no significant decrement in field performance during the exercise. Upper-body anaerobic capacity and strength declined following the exercise, although the results for upper-body strength were not consistent on all measures. Field performance was significantly correlated with measures of upper-body anaerobic capacity and strength. Upper-body strength and anaerobic capacity appear to be important for infantry operations and subject to declines during combat operations.

Fc receptors for IgE (Fc epsilon R) on human lymphoid cells: inducible expression of Fc epsilon RII (CD23) on lymphocytes and detection by monoclonal anti-Fc epsilon RII antibody

The studies presented herein describe (1) a sensitive, quantitative, and objective assay for detecting cell membrane-bound form of Fc receptors for IgE displayed on human lymphoid cells based on measuring unlabeled Fc epsilon R-bound IgE by a solid-phase RIA of cell lysate fluids; (2) the development and characterization of an IgM monoclonal antibody, termed 7E4, which is specific for human lymphocyte Fc epsilon RII (CD23) molecules; and (3) a system for reproducibly inducing de novo synthesis and expression of Fc epsilon RII proteins on human lymphocytes following exposure to the mitogenic lectin, pokeweed mitogen. The Fc epsilon RII molecules induced by exposure to PWM were proven to be present on lymphocytes, and not on other cell types in several ways, including (1) documenting sensitivity of such proteins to both acid pH and trypsin treatment, the latter manipulation being ineffective in removing Fc epsilon RII molecules on basophils and mast cells; (2) demonstrating specific reactivity of the expressed Fc epsilon RII molecules with the 7E4 monoclonal antibody, which is specific for human lymphocyte Fc epsilon RII molecules and does not react with Fc epsilon R molecules on other cell types; and (3) observing the required concomitant presence of both T and B lymphocytes during the induction process and proving that the induced Fc epsilon R+ cells are indeed B cells of the Leu-12+ phenotype by fluorescence analysis. The ability to induce expression of Fc epsilon RII molecules on human lymphocytes exposed to a mitogen such as PWM requires special technical attention to the method of preparation and isolation of human lymphoid cells from peripheral blood. This in vitro system for up-regulating Fc epsilon RII expression on human lymphocytes should provide us with an important new tool to analyze the participation of such cells in the regulatory mechanisms controlling the human IgE antibody system.

Accidental hemlock poisoning

Images

Ascorbate potentiates DNA damage by 1-methyl-1-nitrosourea in vivo and generates DNA strand breaks in vitro

Ascorbic acid (vitamin C) is an important intracellular reducing agent. It also has been suggested to be (i) a protective agent against development of cancer, (ii) a therapeutic agent for malignancies and (iii) a mutagen. We have found that high concentrations of ascorbate leads to DNA damage in several in vivo and in vitro situations. Guinea-pigs receiving oral 1-methyl-1-nitrosourea (MNU) were used as a whole animal model. Administration of sodium ascorbate prior to MNU increased strand breakage in pancreatic DNA. Concentrations of ascorbate greater than 0.5 mM increased the frequency of DNA strand breaks caused by MNU in both L1210 murine leukemia cells and guinea-pig pancreatic cells in tissue culture; ascorbate alone led to DNA strand breaks in the latter cells. Investigations of the mechanism of DNA damage were carried out with purified DNA. Ascorbate produced single- and double-strand breaks in plasmid DNA. Cleavage was catalyzed by copper(II), inhibited by catalase and blocked by the presence of thiols. We conclude that superoxide and hydrogen peroxide produced during the oxidation of ascorbate leads to generation of hydroxyl free radicals that can mediate DNA strand scissions and potentiate the effects of alkylating carcinogens.