Multiple ganglion cysts (‘cystic ganglionosis’): an unusual presentation in a child

A case of multifocal and recurrent ganglion cysts is described. An 11-year-old boy was referred because of symptomatic cystic masses in the extremities since the age of 2 years. Over the years, he had experienced intermittent appearance of these lesions, which were associated with pain, but without any systemic manifestations. Magnetic resonance imaging (MRI) showed cystic lesions with synovio-capsular thickening along the temporomandibular joints (TMJ), atlanto-axial synovial articulation, and tendons and joints of the right wrist and hand. Histopathological examination of one lesion showed anastomosing fibro-connective tissue surrounded by a wall of smooth muscle and fibrous connective tissue, findings that were consistent with ganglion cyst. The early onset of the disease, as well as the involvement of multiple and unusual sites, including the TMJ, implies a genetic susceptibility to these lesions that we refer to as 'cystic ganglionosis'.

Phase II study of rabbit anti-thymocyte globulin, cyclosporine and granulocyte colony-stimulating factor in patients with aplastic anemia and myelodysplastic syndrome

We investigated efficacy and safety of rabbit anti-thymocyte globulin (rATG), cyclosporine and granulocyte colony-stimulating factor (G-CSF) as first-line therapy for patients with aplastic anemia (AA) and low or intermediate-1 or hypoplastic myelodysplastic syndrome (MDS). rATG 3.5 mg/kg (or 2.5 mg/kg per day for patients >or=55 years with MDS) was given for 5 days. Cyclosporine (5 mg/kg) and G-CSF (5 microg/kg) were given daily and continued for up to 6 months or longer. Responses were assessed about 3 and 6 months after therapy. Thirty-six patients have been enrolled on study and 32 patients treated; 25 were evaluable for a response (13 with AA, 12 with MDS); the rest are too early. The median age was 62 years (range, 20-83) for patients with AA and 63 (range, 42-80) for patients with MDS. Of 13 patients, 12 (92%) patients with AA responded (5 complete response (CR), 7 partial response (PR)), whereas of 12 patients, 4 (33%) patients with MDS responded (1 CR, 3 PR). For patients with AA, the median time to response (TTR) was 93 days (range, 79-623), whereas in the MDS group the median TTR was 111 days (range, 77-139). Grade III/IV toxicities were mainly cytopenias and neutropenic fever. Combination of rATG, cyclosporine and G-CSF is safe and effective as first-line treatment of AA and has significant activity in low-risk MDS.

Phase I/II study of idarubicin (Ida), high-dose ara-C, and sorafenib (S) in patients (pts) younger than 65 years with acute myeloid leukemia (AML)

7018

Background: S is an oral multi-kinase inhibitor with activity against the Raf/ERK/MEK pathway and FLT3. It selectively induces apoptosis in FLT3-mutant human AML cell lines at nM concentrations. Methods: Objectives of this study are to determine the tolerability and efficacy of combination of S with chemotherapy. Ara-C 1.5 g/m2 over 24 hrs daily x 4 (x 3 for pts over 60) and Ida 12 mg/m2 daily x 3 are administered with S. In the phase I part, pts with relapsed AML were treated with escalating doses of S (400 mg qod, 400 mg daily, 400 mg bid) for 7 days during induction, and 400 mg bid was established as safe. Pts achieving CR receive up to 5 courses of consolidation with Ida 8 mg/m2 daily x 2 and Ara-C 0.75 g/m2 daily x 3 in addition to S 400 mg bid for up to 28 days per cycle repeated every 4 to 6 weeks. Maintenance is with S 400 mg bid for up to a year. Results: 10 pts (median age 34, range 21–58) with relapsed AML (median prior therapy 2, range 1–6) were treated in the phase I . 7 were FLT3-ITD positive. 4 achieved CR; 6 failed. In the phase II part, 45 pts (12 with FLT3-ITD and 2 with FLT3-TKD) were treated. Median age is 53 (range 18 - 65). Cytogenetics were diploid in 19, +8 in 5, -5/-7 in 5, 11q23 in 2, other in 14. Median presentation WBC was 4.9 x 109/L (range 0.6 - 122.7 x 109/L). 8 pts were FLT3-ITD+/NPM1-. 40 pts are evaluable for response and 85% achieved CR (n = 30) or CRp (n = 4) (13 of 14 FLT3 mutated pts); 5 pts are too early (1 FLT3 mutated). Most frequent grade 3 and higher related adverse events: hyperbilirubinemia (5), rash and hand-foot syndrome (3), raised transaminases (2), diarrhea (2), hypertension (2). With a median f/u of 5.4 mo (range, 0.5 - 11.3), the probability of survival at 6 mo is 81.6%. 5 pts have relapsed; median CR duration has not been reached, (range; 0.2+ - 10.6+ mo). Among pts with FLT3 mutation, 4 have relapsed and 9 remain in CR. Plasma inhibitory assay was performed using day 7 samples from 10 pts; mutant FLT3 was suppressed by all with 5-fold more potent suppression against mutant versus wild-type FLT3. Conclusions: S can be safely combined with IA; it has a high CR rate in frontline therapy of younger pts with AML, in particular those with FLT3 mutations. Correlative studies confirm potent activity of S against FLT3 signaling.

[Table: see text]

Global-scale analyses of chemical ecology and population genetics in the invasive Argentine ant

Ants are some of the most abundant and ecologically successful terrestrial organisms, and invasive ants rank among the most damaging invasive species. The Argentine ant is a particularly well-studied invader, in part because of the extreme social structure of introduced populations, known as unicoloniality. Unicolonial ants form geographically vast supercolonies, within which territorial behaviour and intraspecific aggression are absent. Because the extreme social structure of introduced populations arises from the widespread acceptance of conspecifics, understanding how this colonymate recognition occurs is key to explaining their success as invaders. Here, we present analyses of Argentine ant recognition cues (cuticular hydrocarbons) and population genetic characteristics from 25 sites across four continents and the Hawaiian Islands. By examining both hydrocarbon profiles and microsatellite genotypes in the same individual ants, we show that native and introduced populations differ in several respects. Both individual workers and groups of nestmates in the introduced range possess less diverse chemical profiles than ants in the native range. As previous studies have reported, we also find that introduced populations possess much lower levels of genetic diversity than populations in the native range. Interestingly, the largest supercolonies on several continents are strikingly similar to each other, suggesting that they arose from a shared introduction pathway. This high similarity suggests that these geographically far-flung ants may still recognize and accept each other as colonymates, thus representing distant nodes of a single, widely distributed supercolony. These findings shed light on the behaviour and sociality of these unicolonial invaders, and pose new questions about the history and origins of introduced populations.

Number of nitrate groups determines reactivity and potency of organic nitrates: a proof of concept study in ALDH-2-/- mice

BACKGROUND AND PURPOSE

Mitochondrial aldehyde dehydrogenase (ALDH-2) has been shown to provide a pathway for bioactivation of organic nitrates and to be prone to desensitization in response to highly potent, but not to less potent, nitrates. We therefore sought to support the hypothesis that bioactivation by ALDH-2 critically depends on the number of nitrate groups within the nitrovasodilator.

EXPERIMENTAL APPROACH

Nitrates with one (PEMN), two (PEDN; GDN), three (PETriN; glyceryl trinitrate, GTN) and four (pentaerithrityl tetranitrate, PETN) nitrate groups were investigated. Vasodilatory potency was measured in isometric tension studies using isolated aortic segments of wild type (WT) and ALDH-2-/- mice. Activity of the cGMP-dependent kinase-I (reflected by levels of phosphorylated VAsodilator Stimulated Phosphoprotein, P-VASP) was quantified by Western blot analysis, mitochondrial dehydrogenase activity by HPLC. Following incubation of isolated mitochondria with PETN, PETriN-chromophore and PEDN, metabolites were quantified using chemiluminescence nitrogen detection and mass spectrometry.

KEY RESULTS

Compared to WT, vasorelaxation in response to PETN, PETriN and GTN was attenuated about 10fold in ALDH-2-/- mice, identical to WT vessels preincubated with inhibitors of ALDH-2. Reduced vasodilator potency correlated with reduced P-VASP formation and diminished biotransformation of the tetranitrate- and trinitrate-compounds. None of these findings were observed for PEDN, GDN and PEMN.

CONCLUSIONS AND IMPLICATIONS

Our results support the crucial role of ALDH-2 in bioactivating highly reactive nitrates like GTN, PETN and PETriN. ALDH-2-mediated relaxation by organic nitrates therefore depends mainly on the number of nitrate groups. Less potent nitrates like PEDN, GDN and PEMN are apparently biotransformed by other pathways.

Use of image analysis techniques for objective quantification of the efficacy of different hair removal methods

In the field of consumer-used cosmetics for hair removal and hair growth reduction, there is a need for improved quantitative methods to enable the evaluation of efficacy and claim support. Optimized study designs and investigated endpoints are lacking to compare the efficacy of standard methods, like shaving or plucking, with new methods and products, such as depilating instruments or hair-growth-reducing cosmetics. Non-invasive image analysis, using a high-performance microscope combined with an optimized image analysis tool, was investigated to assess hair growth. In one step, high-resolution macrophotographs of the legs of female volunteers after shaving and plucking with cold wax were compared to observe short-term hair regrowth. In a second step, images obtained after plucking with cold wax were taken over a long-term period to assess the time, after which depilated hairs reappeared on the skin surface. Using image analysis, parameters like hair length, hair width, and hair projection area were investigated. The projection area was found to be the parameter most independent of possible image artifacts such as irregularities in skin or low contrast due to hair color. Therefore, the hair projection area was the most appropriate parameter to determine the time of hair regrowth. This point of time is suitable to assess the efficacy of different hair removal methods or hair growth reduction treatments by comparing the endpoint after use of the hair removal method to be investigated to the endpoint after simple shaving. The closeness of hair removal and visible signs of skin irritation can be assessed as additional quantitative parameters from the same images. Discomfort and pain rating by the volunteers complete the set of parameters, which are required to benchmark a new hair removal method or hair-growth-reduction treatment. Image analysis combined with high-resolution imaging techniques is a powerful tool to objectively assess parameters like hair length, hair width, and projection area. To achieve reliable data and to reduce well known image-analysis artifacts, it was important to optimize the technical equipment for use on human skin and to improve image analysis by adaptation of the image-processing procedure to the different skin characteristics of individuals, like skin color, hair color, and skin structure.

[Mutation in factor II and factor V gene in patients with peripheral arterial occlusive disease]

Mutations in factor-V- and factor-II-genes are correlated with an increased risk for venous thrombosis according to the literature. The significance of the mutations in factor- II- and factor-V-genes for the development of the peripheral arterial occlusive disease is not known. Therefore, we investigated the presence of these mutations in 152 patients with documented peripheral arterial occlusive disease and 318 controls without peripheral arterial occlusive disease with polymerase chain reaction (PCR). There was no association between factor-II-mutation and peripheral arterial occlusive disease. The factor-V-mutation, however, was increased in patients with peripheral arterial occlusive disease double fold (12 positive cases in 318 controls, 12 positive cases in 152 patients with peripheral arterial occlusive disease). The significance level was reached (p = 0.05) in statistical analysis but the result did not fall below the significance level as necessary to reach statistical significance (odds ratio 2.19). Nevertheless, from these data we have to discuss a biological relevance of factor-V-mutation in the pathogenesis of peripheral arterial occlusive disease.

Chronisch-arterielle Verschlusskrankheit der Beine im Stadium IIb-IV

Die Faktor-V- und Faktor-II-Mutationen sind nach der Literatur mit einem erhöhten Risiko für venöse Thrombosen verbunden. Die Bedeutung der Mutationen im Faktor-IIund -V-Gen für die Entstehung und das Fortschreiten der arteriellen Verschlusskrankheit ist bislang nicht geklärt. Wir untersuchten das Vorhandensein dieser Mutationen bei 152 Patienten mit dokumentierter pAVK und 318 Kontrollen (ohne pAVK) mittels Polymerase-Kettenreaktion (PCR) und RFLP-Analyse. Die Ergebnisse erbrachten keinen Hinweis auf eine Assoziation zwischen einer Faktor-II-Mutation und der Entstehung einer pAVK. Dagegen waren Faktor- V-Mutationen bei pAVK-Patienten doppelt so häufig zu beobachten wie bei Gesunden (in der Kontrollgruppe ergaben sich 12 positive Fälle bei 318 Probanden, in der Patientengruppe ergaben sich 12 positive Fälle bei 152 Patienten). In der statistischen Analyse wurde das Signifikanzniveau (p = 0,05) zwar erreicht, aber nicht unterschritten. Das Chancenverhältnis (Odds-Ratio) betrug 2,19 (Konfidenzintervall 0,96-4,99). Schlussfolgerung: Die biologische Relevanz der Faktor-V-Mutation in der Pathogenese der pAVK kann aufgrund unserer Daten diskutiert werden.

Early and Long-term Results of Replacement of the Descending Aorta

OBJECTIVES

The aim of this analysis was to evaluate our results of open surgery on the descending thoracic aorta as benchmark to define indications for endovascular treatment.

METHODS

Between January 1981 and December 2000, 115 patients underwent replacement of the descending or thoraco-abdominal aorta. Follow-up to 20 years was complete in 98%.

RESULTS

Early mortality was 19% and paraplegia rate was 7%. Surgery before 1990 and coronary artery disease were independent predictors for early mortality. Thoraco-abdominal repair and normothermia were independent predictors for paraplegia. Ten years survival rate was 63%.

CONCLUSIONS

Our results confirm that replacement of the descending aorta can be performed today with acceptable low mortality and morbidity and with consistent exclusion of the aneurysm or dissection. Long-term results of endovascular stent-grafts in the descending aorta are unclear. In our opinion endovascular stent-grafts should be reserved for high risk patients, acute dissection or acute aortic rupture.

Infrainguinal ePTFE vascular graft with bioactive surface heparin bonding. First clinical results

AIM

The ultimate aim of improved expanded polytetrafluoroethylene (ePTFE) vascular graft design is to achieve patency rates in femoropopliteal bypass grafting comparable with autologous saphenous vein grafts. Enhanced thromboresistance of the ePTFE material by bioactive surface heparin bonding is one conceivable path toward this goal. This retrospective study was performed to collect the first clinical data for a new ePTFE graft with bioactive surface heparin immobilization.

METHODS

Between March 2003 and February 2004, 43 femoropopliteal or femorocrural ePTFE vascular prostheses with bioactive end-point immobilized heparin (Gore-Tex Propaten Vascular Graft), using the Car-meda BioActive Surface technology, were implanted in 40 patients. Twelve prostheses were implanted in above-knee and 31 in below-knee position. The indication for bypass grafting was limb-threatening ischemia in 88% of the patients. The mean follow-up was 16.6 months.

RESULTS

The primary 1-year patency was 91% for above-knee bypass grafts and 92% for below-knee bypass grafts. The 2-year primary patency rate for above-knee bypass grafts was 68% and 81% for below-knee bypass grafts. Limb salvage was achieved in 98%. The perioperative mortality was 0%, but during follow-up 22% of the patients died with patent bypass grafts.

CONCLUSIONS

While conventional ePTFE grafts, particularly in the below-knee position, have shown poor results even in the short-term, the bioactive heparinized ePTFE graft evaluated in this study provides patency rates comparable with autologous vein grafts. Because the influence of luminal heparin bonding is not only limited to thromboresistance but has impact on, amongst other elements, protein adsorption (thereby improving hemocompatibility), a continuous effect for long-term patency could also be expected.

A chemical level in the coevolutionary arms race between an ant social parasite and its hosts

Here we investigate the coevolutionary interactions between the slavemaking ant Protomognathus americanus and its Temnothorax hosts on a chemical level. We show that, although this social parasite is principally well-adapted to its hosts' cuticular hydrocarbon profile, there are pronounced differences in the fine-tuning of this adaptation. Between populations, chemical adaptation varies with host community composition, as the parasite faces a trade-off when confronted with more than one host species. In addition to adaptation of its own chemical signature, the slavemaker causes a reciprocal adjustment in its slaves' cuticular profile, the degree of which depends on the slave species. On the host side, successful parasite defence requires efficient enemy recognition, and in behavioural aggression trials, host colonies could indeed discriminate between invading slaves, which commonly accompany slavemakers on raids, and free-living conspecifics. Furthermore, hosts shifted their acceptance threshold over the seasons, presumably to reduce the costs of defence.

Toxicity of concentrated sodium hypochlorite used as an endodontic irrigant

AIM

To present a clinical case that illustrates the toxicity of concentrated sodium hypochlorite (NaOCl) on vital tissues.

SUMMARY

The severe clinical consequences of extruding concentrated NaOCl into the periradicular tissues during root canal irrigation are described. After diagnosis of external resorption in tooth 34, endodontic treatment was initiated. Following irrigation with a concentrated NaOCl solution, a rapidly developing swelling and haematoma were visible. During the next few days, an extensive bruise and local necrosis of the oral mucosa developed. After healing of the involved tissues, the canal was prepared and obturated. At this time, no clinical symptoms remained.

KEY LEARNING POINTS

* The use of concentrated NaOCl as a root canal irrigant might cause severe clinical problems when extruded into vital tissues. * The present report confirms the known toxicity of NaOCl to soft tissues following inadvertent extrusion. * To avoid extrusion, it is always prudent to confirm the length and integrity of the root canal system before irrigating with concentrated solutions.

Molecular determinants of virulence, cell tropism, and pathogenic phenotype of infectious bursal disease virus

Infectious bursal disease viruses (IBDVs), belonging to the family Birnaviridae, exhibit a wide range of immunosuppressive potential, pathogenicity, and virulence for chickens. The genomic segment A encodes all the structural (VP2, VP4, and VP3) and nonstructural proteins, whereas segment B encodes the viral RNA-dependent RNA polymerase (VP1). To identify the molecular determinants for the virulence, pathogenic phenotype, and cell tropism of IBDV, we prepared full-length cDNA clones of a virulent strain, Irwin Moulthrop (IM), and constructed several chimeric cDNA clones of segments A and B between the attenuated vaccine strain (D78) and the virulent IM or GLS variant strain. Using the cRNA-based reverse-genetics system developed for IBDV, we generated five chimeric viruses after transfection by electroporation procedures in Vero or chicken embryo fibroblast (CEF) cells, one of which was recovered after propagation in embryonated eggs. To evaluate the characteristics of the recovered viruses in vivo, we inoculated 3-week-old chickens with D78, IM, GLS, or chimeric viruses and analyzed their bursae for pathological lesions 3 days postinfection. Viruses in which VP4, VP4-VP3, and VP1 coding sequences of the virulent strain IM were substituted for the corresponding region in the vaccine strain failed to induce hemorrhagic lesions in the bursa. In contrast, viruses in which the VP2 coding region of the vaccine strain was replaced with the variant GLS or virulent IM strain caused rapid bursal atrophy or hemorrhagic lesions in the bursa, as seen with the variant or classical virulent strain, respectively. These results show that the virulence and pathogenic-phenotype markers of IBDV reside in VP2. Moreover, one of the chimeric viruses containing VP2 sequences of the virulent strain could not be recovered in Vero or CEF cells but was recovered in embryonated eggs, suggesting that VP2 contains the determinants for cell tropism. Similarly, one of the chimeric viruses containing the VP1 segment of the virulent strain could not be recovered in Vero cells but was recovered in CEF cells, suggesting that VP1 contains the determinants for cell-specific replication in Vero cells. By comparing the deduced amino acid sequences of the D78 and IM strains and their reactivities with monoclonal antibody 21, which binds specifically to virulent IBDV, the putative amino acids involved in virulence and cell tropism were identified. Our results indicate that residues Gln at position 253 (Gln253), Asp279, and Ala284 of VP2 are involved in the virulence, cell tropism, and pathogenic phenotype of virulent IBDV.

[TPO immunostaining of the solitary, cold thyroid nodules]

INTRODUCTION

The chance of malignancy in scintigraphically cold thyroid nodules is 2-24%. Differentiation between malignant and benign cytology is difficult. The aim of this study was to evaluate the ability of immunostaining (MoAB47--raised against thyroid peroxidase (TPO)) to differentiate between malignant and benign cells taken from cold thyroid nodules by fine needle aspiration biopsy (FNAB) in order to reduce the number of unnecessary thyroid operations.

MATERIALS AND METHODS

One hundred and eighty-one patients (150 female) with a scintigraphically cold, solitary thyroid nodule were entered between 1993 and 1996. Fifty-seven were excluded for various reasons. Material removed by FNAB was stained with MoAB47 and routine staining. Staining of 80% or more of the cells was considered benign, less than 80% was considered malignant. Routine staining of operatively removed material was used as the final diagnosis.

RESULTS

A pattern with negative TPO staining was found in all lesions that were subsequently proved to be malignant. In all but one, the lesions subsequently diagnosed as being benign stained positive for TPO. The sensitivity and specificity were respectively 1.0 and 0.99.

CONCLUSION

TPO immunostaining of material removed by FNAB is a powerful tool in the differentiation between benign and malignant tumours.

Identification, Substrate Specificity, and Inhibition of theStreptococcus pneumoniae β-Ketoacyl-Acyl Carrier Protein Synthase III (FabH)

In the bacterial type II fatty acid synthase system, beta-ketoacyl-acyl carrier protein (ACP) synthase III (FabH) catalyzes the condensation of acetyl-CoA with malonyl-ACP. We have identified, expressed, and characterized the Streptococcus pneumoniae homologue of Escherichia coli FabH. S. pneumoniae FabH is approximately 41, 39, and 38% identical in amino acid sequence to Bacillus subtilis, E. coli, and Hemophilus influenzae FabH, respectively. The His-Asn-Cys catalytic triad present in other FabH molecules is conserved in S. pneumoniae FabH. The apparent K(m) values for acetyl-CoA and malonyl-ACP were determined to be 40.3 and 18.6 microm, respectively. Purified S. pneumoniae FabH preferentially utilized straight short-chain CoA primers. Similar to E. coli FabH, S. pneumoniae FabH was weakly inhibited by thiolactomycin. In contrast, inhibition of S. pneumoniae FabH by the newly developed compound SB418011 was very potent, with an IC(50) value of 0.016 microm. SB418011 also inhibited E. coli and H. influenzae FabH with IC(50) values of 1.2 and 0.59 microm, respectively. The availability of purified and characterized S. pneumoniae FabH will greatly aid in structural studies of this class of essential bacterial enzymes and facilitate the identification of small molecule inhibitors of type II fatty acid synthase with the potential to be novel and potent antibacterial agents active against pathogenic bacteria.

Synthesis of an aza analogue of 2-deoxy-D-ribofuranose and its homologues

Azasugars were obtained in one-pot reactions by catalytic reduction reactions of amino group precursors in aldosugars followed by intramolecular reductive amino alkylation reactions. (3R,4S)-4-[(1S)-1,2-Dihydroxyethyl]pyrrolidin-3-ol was obtained from D-xylose by two different strategies through 3-C-cyano-3-deoxy-D-ribo-pentofuranose or 3-C-azidomethyl-3-deoxy-D-ribo-pentofuranose in 6 and 16% overall yields, respectively. The oxidative cleavage of the diol group in the corresponding Fmoc-azasugar followed by deprotection afforded (3R,4R)-4-(hydroxymethyl)pyrrolidin-3-ol. (3R,4S)-4-[(1S,2R)-1,2,3-Trihydroxypropyl]pyrrolidin-3-ol was synthesized from diacetone-D-glucose through 3-deoxy-3-C-nitromethyl-D-allose and the overall yield was 7%.

Lipoblastoma and lipoblastomatosis in infancy and childhood: histopathologic, ultrastructural, and cytogenetic features

Lipoblastoma is a relatively rare tumor that occurs in infancy and early childhood and arises from embryonic white fat. Although a benign tumor, lipoblastomas tend to recur and may resemble myxoid liposarcoma. The authors report 26 cases over a 15-year period at Texas Children's Hospital. There was a slight female predilection (14F:12M). The most common symptom was a painless mass with or without increasing size. The trunk, extremities, head and neck, retroperitoneum, inguinal canal, peritoneal cavity, and lung were the tumor sites. Most tumors were circumscribed lipoblastomas and the minority were diffuse infiltrative lipoblastomatosis. Reexcision for residual or recurrent tumor was necessary more frequently in patients with lipoblastomatosis. Histopathologic examination and ultrastructural examination revealed cellular neoplasms composed of immature adipocytes with relatively well-defined septa, frequent lipoblasts, a fine vascular network, and often a myxoid appearance resembling myxoid liposarcoma. Cytogenetics was performed in 4 cases with chromosome 8q abnormality being most common. The major concern with lipoblastoma in children is to completely excise the tumor to avoid leaving residual tumor and to prevent recurrences. Confusion with myxoid liposarcoma, well-differentiated liposarcoma, and typical lipomas may occur. Although asymptomatic, lipoblastomas may cause dysfunction of other organ systems due to mass effect. Complete surgical excision with at least 2 years of follow-up is the preferred therapy.

Modulating the distribution of fluxes among respiration and fermentation by overexpression of HAP4 in Saccharomyces cerevisiae

The tendency of Saccharomyces cerevisiae to favor alcoholic fermentation over respiration is a complication in aerobic, biomass-directed applications of this yeast. Overproduction of Hap4p, a positive transcriptional regulator of genes involved in respiratory metabolism, has been reported to positively affect the balance between respiration and fermentation in aerobic glucose-grown batch cultures. In this study, the effects of HAP4 overexpression have been quantified in the prototrophic S. cerevisiae strain CEN.PK 113-7D under a variety of growth conditions. In aerobic glucose-limited chemostat cultures, overexpression of HAP4 increased the specific growth rate at which aerobic fermentation set in by about 10% relative to the isogenic wild-type. Upon relief of glucose-limited conditions, the HAP4-overexpressing strain produced slightly less ethanol than the wild-type strain. The effect of Hap4p overproduction was most drastic in aerobic, glucose-grown chemostat cultures in which ammonium was limiting. In such cultures, the biomass yield on glucose was double that of the wild-type.

Proteinuria and perinatal lethality in mice lacking NEPH1, a novel protein with homology to NEPHRIN

A high-throughput, retrovirus-mediated mutagenesis method based on gene trapping in embryonic stem cells was used to identify a novel mouse gene. The human ortholog encodes a transmembrane protein containing five extracellular immunoglobulin-like domains that is structurally related to human NEPHRIN, a protein associated with congenital nephrotic syndrome. Northern analysis revealed wide expression in humans and mice, with highest expression in kidney. Based on similarity to NEPHRIN and abundant expression in kidney, this protein was designated NEPH1 and embryonic stem cells containing the retroviral insertion in the Neph1 locus were used to generate mutant mice. Analysis of kidney RNA from Neph1(-/-) mice showed that the retroviral insertion disrupted expression of Neph1 transcripts. Neph1(-/-) pups were represented at the expected normal Mendelian ratios at 1 to 3 days of age but at only 10% of the expected frequency at 10 to 12 days after birth, suggesting an early postnatal lethality. The Neph1(-/-) animals that survived beyond the first week of life were sickly and small but without edema, and all died between 3 and 8 weeks of age. Proteinuria ranging from 300 to 2,000 mg/dl was present in all Neph1(-/-) mice. Electron microscopy demonstrated NEPH1 expression in glomerular podocytes and revealed effacement of podocyte foot processes in Neph1(-/-) mice. These findings suggest that NEPH1, like NEPHRIN, may play an important role in maintaining the structure of the filtration barrier that prevents proteins from freely entering the glomerular urinary space.

Severe obesity does not adversely affect perioperative mortality and morbidity in coronary artery bypass surgery

OBJECTIVE

Obese patients are usually thought to have an increased risk for complications in coronary artery bypass surgery.

METHODS

Therefore, the data of 500 consecutive patients undergoing coronary artery bypass grafting at our department in 1998 by use of cardiopulmonary bypass were analyzed. Severe obesity was defined as body mass index (BMI) > or = 30.0 kg/m(2). Obese patients (n=100; group O) were compared to the remaining 400 patients (group C). Both groups were comparable with respect to sex, history of prior myocardial infarction, chronic obstructive pulmonary disease, previous stroke, duration of cardiopulmonary bypass, aortic cross-clamp time and number of distal anastomoses performed. Obese patients were slightly younger and diabetes and hypertension were more common in these patients.

RESULTS

Survival and potential complications including perioperative myocardial infarction, sternal wound infection, wound infection at the leg, renal failure, stroke, prolonged mechanical ventilation, pneumonia, reexploration for bleeding, and atrial arrhythmias were analyzed. No significant differences between obese and non-obese patients were detected.

CONCLUSION

Severe obesity does not necessarily adversely affect perioperative mortality and morbidity in patients undergoing coronary artery bypass grafting in this study.

The impact of ultrasound examinations on the management of children with suspected appendicitis: a 3-year analysis

BACKGROUND/PURPOSE

The aim of this study was to evaluate the usefulness of ultrasonography in the routine management of children with suspected appendicitis in a children's hospital.

METHODS

Data from surgical, radiologic, and pathologic databases were cross referenced retrospectively to allow for review of all children undergoing appendectomy and all children undergoing an ultrasound scan to rule out appendicitis in the 3-year period August 1, 1996 to July 31, 1999.

RESULTS

Pathology reports were available for 1,007 of 1,032 patients undergoing appendectomy. Eighty-four percent had acute appendicitis (26% of these were perforated). Fifty-eight percent of all children undergoing appendectomy had at least 1 preoperative ultrasound scan. Eighty-six percent of those having ultrasound scans had acute appendicitis compared with 82% of those who did not have an ultrasound scan (P <.05 chi(2) Test). During the same period, 2,056 ultrasound examinations were performed by staff radiologists who were available 24 hours a day to rule out appendicitis. Ultrasonography in this setting had a sensitivity of 89%, specificity of 95%, positive predictive value of 86%, and a negative predictive value of 96% (true-positives, n = 496; false-positive, n = 81; true-negative, n = 1,417; false-negative, n = 62). An alternate ultrasound diagnosis was offered in 157 children.

CONCLUSIONS

Ultrasound scan improves diagnostic accuracy in children with suspected appendicitis. The high negative predictive value of ultrasound scan, especially when used repeatedly, may reduce the need for admission to hospital for clinical observation to rule out appendicitis.