Frequency of sister chromatid exchange in chrysotile-exposed workers

Chrysotile, which is an industrial carcinogen, has been shown to induce a dose-dependent increase in the frequency of sister chromatid exchange (SCE) in vitro. Authors designed this study to examine the increase of SCEs frequency in the workers occupationally exposed to chrysotile. Heparinized whole blood samples from 45 chrysotile-exposed and 45 control volunteers were cultured for 72 h. The significant difference of SCE frequency was found between chrysotile-exposed workers and control group. The highest SCEs frequency was found in chrysotile-exposed smokers, and the lowest in control non-smokers. The effect of chrysotile exposure on SCEs was marginally significant after controlling the effects of age and smoking by multiple regression analysis.

Low-grade malignant perineurioma of the paravertebral column, transforming into a high-grade malignancy

A demarcated 6 x 5 cm right paravertebral tumor at the level of T6 in a 39-year-old male was removed surgically. Histologically, the tumor consisted of monomorphous benign-looking, low-cellular spindle cells embedded in desmoplastic stroma. Ten years later, the tumor recurred locally with metastasis to systemic organs, including the occipital skin. Malignancy was histologically evident by the increased cellularity, cellular atypia and mitotic activity. The patient died of respiratory failure at the age of 49. Retrospectively reviewed, the primary lesion was low-grade fibrosarcoma-like spindle cell tumor, with secondary transformation into a highly malignant form. The differential diagnoses included sclerosing epithelioid fibrosarcoma, low-grade fibromyxoid sarcoma and malignant peripheral nerve sheath tumor. Immunohistochemically, the spindle cells in the primary and recurrent tumors consistently expressed epithelial membrane antigen, vimentin, type 4 collagen and laminin. The tumor cells in the present case showed a differentiation toward perineurial cells, which are normally positive for these immunohistochemical markers. Hence, the appropriate diagnostic term should be 'malignant perineurioma', a subtype of malignant peripheral nerve sheath tumor.

1',2',3',4'-tetradehydrotubulosine, a cytotoxic alkaloid from Pogonopus speciosus

Bioassay-guided phytochemical investigation of the stems of Pogonopus speciosus, using human oral epidermoid carcinoma (KB) cells as a monitor, led to the isolation of a novel alkaloid, 1',2', 3',4'-tetradehydrotubulosine (1), along with tubulosine (2) and psychotrine (3) as bioactive constituents. The structure of the novel compound was elucidated through 1D- and 2D-NMR spectroscopic methods. Alkaloids 1 and 3 showed weak cytotoxic activity against a panel of human cancer cell lines, with the potency of these compounds being markedly less than that of tubulosine (2).

EST analysis of gene expression in early cleavage-stage sea urchin embryos

A set of 956 expressed sequence tags derived from 7-hour (mid-cleavage) sea urchin embryos was analyzed to assess biosynthetic functions and to illuminate the structure of the message population at this stage. About a quarter of the expressed sequence tags represented repetitive sequence transcripts typical of early embryos, or ribosomal and mitochondrial RNAs, while a majority of the remainder contained significant open reading frames. A total of 232 sequences, including 153 different proteins, produced significant matches when compared against GenBank. The majority of these identified sequences represented ‘housekeeping’ proteins, i.e., cytoskeletal proteins, metabolic enzymes, transporters and proteins involved in cell division. The most interesting finds were components of signaling systems and transcription factors not previously reported in early sea urchin embryos, including components of Notch and TGF signal transduction pathways. As expected from earlier kinetic analyses of the embryo mRNA populations, no very prevalent protein-coding species were encountered; the most highly represented such sequences were cDNAs encoding cyclins A and B. The frequency of occurrence of all sequences within the database was used to construct a sequence prevalence distribution. The result, confirming earlier mRNA population analyses, indicated that the poly(A) RNA of the early embryo consists mainly of a very complex set of low-copy-number transcripts.

Antifungal activities of recombinant antifungal protein by conjugation with polyethylene glycol

Tenecin 3, an antifungal protein isolated from coleopteran insect Tenebrio molitor larvae, inhibited growth of the fungus Candida albicans. We have previously reported that tenecin 3 has a propensity of random structure with very loose turn-like elements by circular dichroism (CD) analysis and 2D nuclear overhauser effect spectroscopy [Lee et al. (1999)]. However, the antifungal mechanism of tenecin-3 has not yet been studied due to its very low availability from natural sources. As an initial step to study the antifungal mechanism of tenecin 3, recombinant tenecin 3 (RT-3) obtained from an expression system in Escherichia coli showed antifungal activity against C. albicans as did natural tenecin 3. To elucidate the antifungal mechanism of RT-3 and to explore the possibility of preparing polyethylene glycol (PEG) conjugated derivative, we synthesized PEG conjugated RT-3 (RT-3-PEG) and examined its antifungal activity against C. albicans in vitro. RT-3-PEG showed greater antifungal activity against C. albicans than RT-3 alone at the same dose. When C. albicans was treated with RT-3-PEG in vitro, K+ in the C. albicans cell was leaked out rapidly compared to the C. albicans treated with RT-3 alone. When the morphological change of RT-3-PEG treated C. albicans was examined by scanning electron microscopy, string-like substances, which may have been derived from the fungus, were stacked around the cell whose wall was damaged. Also, no appreciable hemolysis of mouse erythrocytes was detected under conditions in which 1% melittin caused 100% hemolysis. These results suggested that the RT-3-PEG derivative probably does not interact with mammalian cell appreciably, although it has antifungal activity.

Cellular redistribution of PKCalpha, rhoA, and ROKalpha following smooth muscle agonist stimulation

Efficient receptor-coupled activation of smooth muscle requires discrete coordination of many signal transducing events from the plasma membrane to the myofilaments. Recruitment of key factors to the plasma membrane is thought to be crucial for transduction of extracellular signals leading to contractility. We investigated, therefore, for the first time in intact differentiated smooth muscle cells, the distributions of three molecules important for receptor-coupled excitation: protein kinase Calpha (PKCalpha), rhoA, and rho kinase (ROK). We also directly confirmed, by single cell force measurements, carbachol-induced [Ca(2+)](i) sensitization of contractility. Laser scanning confocal immunofluorescent microscopy of central smooth muscle cell sections determined that, at rest, PKCalpha, rhoA, and ROKalpha were distributed predominantly throughout the cytosol. Muscarinic stimulation resulted in significant redistribution of each protein to the cell membrane. By digital image analysis, peripheral:cytosolic distributions of PKCalpha, rhoA, and ROKalpha were calculated as, respectively, 1.05 +/- 0.03 (8), 1.09 +/- 0.03 (5), and 1.26 +/- 0.04 (12) at rest, increasing significantly following stimulation to 2.09 +/- 0.22 (6), 2.02 +/- 0.12 (8), and 1.93 +/- 0.05 (10). It is proposed that this receptor-coupled recruitment to the cell periphery of the downstream signaling molecules PKCalpha, rhoA, and ROKalpha contributes to the efficacy of agonist-induced contractile activation of smooth muscle.

Targeted disruption of the microsomal epoxide hydrolase gene. Microsomal epoxide hydrolase is required for the carcinogenic activity of 7,12-dimethylbenz[a]anthracene

Microsomal epoxide hydrolase (mEH) is a conserved enzyme that is known to hydrolyze many drugs and carcinogens, and a few endogenous steroids and bile acids. mEH-null mice were produced and found to be fertile and have no phenotypic abnormalities thus indicating that mEH is not critical for reproduction and physiological homeostasis. mEH has also been implicated in participating in the metabolic activation of polycyclic aromatic hydrocarbon carcinogens. Embryonic fibroblast derived from the mEH-null mice were unable to produce the proximate carcinogenic metabolite of 7,12-dimethylbenz[a]anthracene (DMBA), a widely studied experimental prototype for the polycylic aromatic hydrocarbon class of chemical carcinogens. They were also resistant to DMBA-mediated toxicity. Using the two-stage initiation-promotion skin cancer bioassay, the mEH-null mice were found to be highly resistant to DMBA-induced carcinogenesis. In a complete carcinogenesis bioassay, the mEH mice were totally resistant to tumorigenesis. These data establish in an intact animal model that mEH is a key genetic determinant in DMBA carcinogenesis through its role in production of the ultimate carcinogenic metabolite of DMBA, the 3,4-diol-1,2-epoxide.

Prevention of postoperative air leakage from lungs using a purified human collagen membrane-polyglycolic acid sheet

BACKGROUND

Human amnion has useful biomedical applications because it contains a large amount of human collagen fibers. We prepared purified human collagen membrane (HCM) from human amnion and used it to develop a new sheet by combining it with synthetic bioabsorbable polyglycolic acid (PGA) mesh. We evaluated its efficacy in preventing air leakage from the lungs of dogs.

METHODS

In 20 dogs, HCM-PGA sheet (n = 5), sheets using fibrin glue with a separate application method (n = 5), a mixed application method (n = 5), and fibrin glue alone (n = 5), were used as dressing materials after partial lung resection.

RESULTS

The HCM-PGA sheet using fibrin glue with a separate application method was shown to be significantly more effective by an air leakage pressure test than the other three methods. These results indicate that the HCM-PGA sheet is useful for preventing air leakage from the lung.

CONCLUSIONS

The HCM-PGA sheet is more effective than conventional fibrin glue for controlling postoperative air leakage.

Impact of regional intestinal pH modulation on absorption of peptide drugs: oral absorption studies of salmon calcitonin in beagle dogs

PURPOSE

To investigate the relationship between the modulation of intestinal pH and the oral absorption properties of a model peptide drug, salmon calcitonin (sCT), in conscious beagle dogs.

METHODS

Studies were performed to characterize the disintegration of the formulation, intestinal pH changes, and the appearance of the peptide in the blood. Enteric-coated formulations containing sCT and various amounts of citric acid (CA) were tethered to a Heidelberg capsule (HC) and given orally to normal beagle dogs. Blood samples were collected and analyzed by radioimmunoassay (RIA). Intestinal pH was continuously monitored using the Heidelberg pH capsule (HC) system. The integrity of the HC-delivery system tether was verified by fluoroscopy.

RESULTS

The intra-individual variation in gastric emptying (GE) of the delivery system was large. There were also large inter-individual differences in the disintegration and absorption properties of the various formulations. However, the peak plasma concentrations of sCT were always observed when the intestinal pH declined. The average baseline intestinal pH was 6.1 +/- 0.2 (mean +/- SEM, n = 12). The intestinal pH reduction was 2.6 +/- 0.4 (mean +/- SEM, n = 12, ranged from 0.5 to 4.0 units from baseline). There was a good correlation between the time to reach the trough intestinal pH (t(pH,min)) and time to reach the peak plasma concentration (tconc,max)) of sCT (t(conc,max) = 0.95 x t(pH,min) + 14.1, n = 11, r2 = 0.91). Plasma Cmax and area under the curve (AUC) increased with increasing amounts of CA in the formulations.

CONCLUSIONS

The results of these studies demonstrate that the oral absorption properties of a model peptide drug, sCT, can be modulated by changing intestinal pH. sCT is a substrate for the pancreatic serine protease trypsin which has maximal activity at pH 5 to 6. Reducing intestinal pH presumably stabilizes sCT in the GI tract enabling greater absorption of the intact peptide.

Management of stage pTxN+ adenocarcinoma of the prostate: influence of radical prostatectomy on progression-free interval

BACKGROUND

Whether stage pN+ prostate cancer patients will benefit from radical prostatectomy remains a controversial issue. We assess the impact of radical prostatectomy on a progression-free interval for patients with stage pN+ prostate cancer.

METHODS

From October 1990 to June 1997, 25 patients were diagnosed with stage pTxN+ adenocarcinoma of the prostate in our institute. Ten of these patients were treated with radical retropubic prostatectomy (RRP) due to false-negative frozen sections at staging pelvic lymphadenectomy. In 15 patients, radical surgery was discontinued because of grossly enlarged lymph nodes and/or positive frozen section results during staging pelvic lymph node dissection (PLND). All patients received immediate androgen ablation therapy with or without radiotherapy. Serum prostate-specific antigen (PSA) was regularly monitored in all patients.

RESULTS

During a median follow-up period of 33 months (range, 15-89 months), eight patients (53%) in the PLND group and two (20%) in the RRP group experienced disease progression as defined by significant elevation of serum PSA concentrations. The median progression-free intervals were 46 and 51 months, respectively. Both univariate and multivariate analyses failed to show statistically significant differences in the progression-free survival between the RRP and PLND groups.

CONCLUSIONS

Based on our limited experience, surgical removal of the primary tumor may have only a marginal effect in terms of the progression-free interval for prostatic cancer patients with metastasized pelvic lymph nodes (p = 0.124, log-rank test). The follow-up period was not long enough to evaluate the difference in cancer-specific survival.

Cell-retained isoforms of vascular endothelial growth factor (VEGF) are correlated with poor prognosis in osteosarcoma

Vascular endothelial growth factor (VEGF) is a major angiogenic factor. Osteosarcoma is characterised by hypervascularity and metastatic potential. We examined VEGF mRNA expression, VEGF isoform pattern and VEGF receptor (flt-1 and KDR) by RT-PCR analysis in 30 osteosarcomas. All 30 osteosarcomas expressed VEGF mRNA. 17 osteosarcomas (57%) expressed flt-1 mRNA, whilst 20 (67%) expressed KDR mRNA. 6/30 (20%) osteosarcomas were positive for VEGF121 only, 8 (27%) for VEGF121 + VEGF165, and 16 (53%) for VEGF121 + VEGF165 + VEGF189. Patients with osteosarcomas with VEGF165 (n = 24) had significantly poorer prognosis in comparison with those without VEGF165 (P = 0.022, Wilcoxon's test). The osteosarcomas with VEGF165 had significantly increased vascularity assessed on sections immunostained for CD34 (P < 0.001, Mann-Whitney U test). Although VEGF165 is a soluble isoform, it is also retained on the cellular surface. These results suggest that cell-retained VEGF isoforms (VEGF165, VEGF189) might be essential for neovascularisation in osteosarcoma, whilst the soluble VEGF121 isoform is not sufficient to stimulate neovascularisation in this type of neoplasm.

Sequential segmental approach to fetal congenital heart disease

The sequential segmental approach is now universally used in the diagnosis of congenital heart disease. Its utilization during fetal sonography has not been well described. In this review, we show how the fetal heart can be approached in a sequential segmental manner by using six basic sonographic views. The transverse view of the fetal upper abdomen is obtained to determine the arrangement of the abdominal organs, which, in most cases, provides the important clues to the determination of the atrial arrangement. The four-chamber view is obtained to evaluate the atrioventricular junctions. The views of the left and right ventricular outflow tracts are obtained to evaluate the ventriculoarterial junctions. The three-vessel view and the aortic arch view are obtained for the evaluation of the arrangement and size of the great arteries, which provides the additional clues to the diagnosis of the abnormalities involving the ventriculoarterial junctions and the great arteries. The standard protocol to acquire these six basic views is also introduced.

Tetralogy of Fallot in the fetus: findings at targeted sonography

OBJECTIVES

To evaluate the findings of tetralogy of Fallot in various fetal sonographic views.

METHODS

We reviewed the fetal sonograms and medical records of 20 fetuses with prenatal diagnosis of tetralogy of Fallot. We analyzed the indications for targeted sonography, the abnormalities seen in various sonographic views, the postnatal echocardiographic and angiographic findings and autopsy findings.

RESULTS

The most common indication for targeted sonography was an abnormal (n = 12) or inadequate (n = 3) finding on sonographic screening in which the abnormality was most frequently found on the three-vessel view (n = 9). The key pathological features of tetralogy of Fallot were uniformly demonstrated in the ventricular outflow tract, three-vessel and short-axis views. The ductus arteriosus was small in 70% of cases and not identifiable in the remaining fetuses. In three of six fetuses with no identifiable ductus, the ductus was shown to be absent at autopsy. The direction of ductal flow was variable.

CONCLUSION

The key features of tetralogy of Fallot were always demonstrable in the ventricular outflow tract, three-vessel and short-axis views. The most common reason for referral was the abnormal three-vessel view.

The imbalance between coagulation and fibrinolysis is related to the severity of the illness and the prognosis in sepsis

OBJECTIVES

The coagulation and fibrinolytic system appears to be activated by the septic process independently, leading to the syndrome of disseminated intravascular coagulation (DIC). In this study, we investigated the changes within the hemostatic system related to the severity of the illness and the prognosis in patients with sepsis.

METHODS

Plasma thrombin-antithrombin III (TAT) and plasmin-alpha 2-antiplasmin (PAP) complexes were measured using ELISA methods in 32 patients with sepsis and 20 controls and were analyzed according to the APACHE III scores and survival of the patients.

RESULTS

Plasma TAT and PAP in patients with sepsis were significantly higher than controls. Nonsurvivors showed greater levels of TAT (21.7 +/- 22.3 ng/mL) and lower levels of PAP (628.4 +/- 378.1 ng/mL) than survivors (TAT: 11.1 +/- 11.2 ng/mL; PAP: 857.1 +/- 364.1 ng/mL). The imbalance between coagulation and fibrinolysis described as TAT/PAP ratio was closely related with APACHE III scores in patients with sepsis (r = 0.47) and the TAT/PAP ratio in nonsurvivors was significantly higher compared with survivors (34.4 +/- 21.4 vs. 14.4 +/- 13.8).

CONCLUSION

In sepsis, both coagulation and the fibrinolysis system are activated and the imbalance between coagulation and fibrinolysis predisposes to the hypercoagulation state and is closely related to the severity of the disease and the prognosis.

Physicochemical evidence that Treponema pallidum TroA is a zinc-containing metalloprotein that lacks porin-like structure

Although TroA (Tromp1) was initially reported to be a Treponema pallidum outer membrane protein with porin-like properties, subsequent studies have suggested that it actually is a periplasmic substrate-binding protein involved in the transport of metals across the treponemal cytoplasmic membrane. Here we conducted additional physicochemical studies to address the divergent viewpoints concerning this protein. Triton X-114 phase partitioning of recombinant TroA constructs with or without a signal sequence corroborated our prior contention that the native protein's amphiphilic behavior is due to its uncleaved leader peptide. Whereas typical porins are trimers with extensive beta-barrel structure, size exclusion chromatography and circular dichroism spectroscopy revealed that TroA was a monomer and predominantly alpha-helical. Neutron activation, atomic absorption spectroscopy, and anomalous X-ray scattering all demonstrated that TroA binds zinc in a 1:1 molar stoichiometric ratio. TroA does not appear to possess structural features consistent with those of bacterial porins.

Treponema pallidum TroA is a periplasmic zinc-binding protein with a helical backbone

The crystal structure of recombinant TroA, a zinc-binding protein component of an ATP-binding cassette transport system in Treponema pallidum, was determined at a resolution of 1.8 A. The organization of the protein is largely similar to other periplasmic ligand-binding proteins (PLBP), in that two independent globular domains interact with each other to create a zinc-binding cleft between them. The structure has one bound zinc pentavalently coordinated to residues from both domains. Unlike previous PLBP structures that have an interdomain hinge composed of beta-strands, the N- and C-domains of TroA are linked by a single long backbone helix. This unique backbone helical conformation was possibly adopted to limit the hinge motion associated with ligand exchange.

Simultaneous reconstruction of the Achilles tendon and soft-tissue defect using only a latissimus dorsi muscle free flap

The combined loss of the Achilles tendon and the overlying soft tissue in the young ambulant patient with expectations of a normal life is a challenging problem. These patients need not only soft tissue but also dynamic and functional reconstruction. Four cases of major defects of the Achilles tendon and overlying soft tissue after trauma are presented. In each case, the tendon and the overlying soft tissues were reconstructed using only a latissimus dorsi muscle free flap and overlying split-thickness skin graft. In conventional methods, evolved in the reconstruction of the Achilles tendon and soft tissue, the size of the defect was a limit. However, this technique can be used to reconstruct an extensive defect, including distal calf muscle to the plantar metatarsal area. In one case, the flap was harvested in a myocutaneous unit, and the skin portion was deepithelialized for the coverage and enough padding on the bony exposure area in reverse position. The purpose of the present study was to reevaluate the potential of denervated muscle flap for a force-bearing conduit as an alternative reconstructive method of the Achilles tendon. The denervated latissimus dorsi muscle in this study eventually experienced the process of atrophy and fibrosis but maintained its original length. Although there remained some atrophic muscle fibers, a fibrosis of the muscle fibers formed a tendon-like fibrous band, and so the action of the posterior calf muscle could be transmitted through the tendon-like fibrotic change of the denervated latissimus dorsi muscle. The advantages of this technique are that (1) it is a single procedure, (2) it is adaptable to a wide range of defect sizes, (3) it allows faster wound healing supported by well-vascularized tissues, (4) it produces satisfactory function of the ankle joint and a padding effect, and (5) it produces good contour of the posterior calf to the sole and an acceptable donor-site morbidity.

Detection of epileptiform activities in the EEG using neural network and expert system

This paper proposes a multichannel spike detection in long term EEG monitoring for epilepsy. It is achieved by wavelet transform(WT), artificial neural network(ANN) and the expert system. First, a small set of wavelet coefficients is used to represent the characteristics of a single channel epileptic spikes and normal activities. The purpose of this WT is to reduce the number of inputs to the ANN. Next, three layer feed-forward network employing the error back propagation algorithm is trained and tested using parameters obtained by the WT. Spikes are identified in individual EEG channels by 16 identical neural networks. Finally, 16-channel expert system based on the context information of adjacent channels is introduced to reject artifacts and produce reliable results. In this study, epileptic spikes and normal activities were selected from 32 patient's EEGs (the seizure disorder: 12, normal: 20) in consensus among experts. The result shows that the WT reduced data input size and the preprocessed ANN had 97% sensitivity and 89.5% selectivity, which were more accurate than that of ANN with the same input size of raw data. In clinical result, our expert rule system, which uses neighboring channel informations, was capable of rejecting artifacts commonly found in EEG recordings.

Isozyme-specific inhibitors of protein kinase C translocation: effects on contractility of single permeabilized vascular muscle cells of the ferret

1. The effects on contractility of three peptides reported to inhibit protein kinase C (PKC) translocation in an isozyme-specific manner were studied: a peptide from the C2 domain of conventional PKCs (C2-2), a peptide from the N-terminal variable domain of epsilonPKC (epsilonV1-2) and a peptide (ABP) from the actin-binding domain of epsilonPKC (epsilon(223-228)). 2. Isometric force was directly recorded from individual hyperpermeable ferret portal vein or aortic smooth muscle cells. 3. Phenylephrine contracted permeabilized portal vein cells at pCa 6.7 but not at pCa 7.0. However, phenylephrine did contract aortic cells at pCa 7.0. 4. C2-2 inhibited phenylephrine-induced contraction, but did not affect resting tension, in portal vein cells at pCa 6.7. In aortic cells at either pCa 6.7 or 7.0, C2-2 had no effect on either basal tension or phenylephrine-induced contraction. 5. ABP did not evoke any changes in phenylephrine-induced contraction or baseline tension in either portal vein or aortic cells. 6. epsilonV1-2 inhibited phenylephrine-induced contraction and decreased resting tension in aortic cells at pCa 7.0, but not in portal vein cells at pCa 6.7. 7. Western blots indicated that portal vein cells contained substantially more alphaPKC than aortic cells. Portal vein cells also contained small amounts of betaPKC, which was undetectable in aortic cells. In contrast, aortic cells contained more epsilonPKC than portal vein cells. Even though epsilonPKC was expressed in portal vein and alphaPKC in aorta, imaging studies indicated that they were not translocated in these cell types. 8. These results suggest that the Ca2+-dependent isozymes of PKC (alpha and/or beta) play a major role in contraction of the portal vein but not of the aorta. In contrast, the results are consistent with epsilonPKC, but not Ca2+-dependent PKC isozymes, regulating contractility of the aorta.

SM37, a skeletogenic gene of the sea urchin embryo linked to the SM50 gene

The genomic DNA region that contains the SM50 gene also included a second gene that appeared to encode another skeletogenic matrix protein. The two genes were linked at a distance of about 12 kb. Based on the molecular weight of the implied protein the gene was termed SM37. The SM37 protein included a long tandem sequence of short glycine-rich repeats that was similar to the glycine-rich repeats included in the SM50 protein and several other skeletal matrix proteins, although the sequence of SM37 repeat was distinct. The overall structure of the SM37 protein was similar to SM50 as well. However, SM37 was only about 30% identical in amino acid sequence to SM50, and coding region probes behaved as a single copy sequence under standard conditions. The SM37 gene included the same cis-regulatory elements as the SM50 gene, although in a different order with respect to transcription. This gene was regulated coordinately with SM50 during development, and like SM50 was expressed exclusively in skeletogenic mesenchyme lineages.

Discordant evolution of asymptomatic proteinuria in identical twins

We describe a pair of 17-year-old identical twin brothers with asymptomatic proteinuria, one of whom showed focal segmental glomerulosclerosis (FSGS) while the other showed immunoglobulin M (IgM) nephropathy. For each twin, audiological examination was normal. There was no family history of renal failure, deafness, or hematuria. HLA typing revealed an identical phenotype consisting of A25, A33, B44, B54, Cw1, Cw7, DR7 and DRB1. There is still controversy about whether minimal change disease, IgM nephropathy, and FSGS are discrete entities or different aspects of the same disease. The coexistence of IgM nephropathy and FSGS in identical twins suggests that the same genetic factors may be involved in the development of both diseases. However, although the brothers are identical twins, they had different eating habits and body weight. The twin who preferred to eat a protein-rich diet and who was heavier developed early proteinuria and manifested FSGS on renal biopsy. The discordant evolution of asymptomatic proteinuria in identical twins may provide a clue for the existence of environmental factors on the progression from IgM nephropathy to FSGS. Therefore, this report provides indirect support for the hypothesis that IgM nephropathy and FSGS represent different aspects in the spectrum of a single disease.

Term pregnancy in a noncommunicating rudimentary horn of an unicornuate uterus: a case report

A case of full-term pregnancy in the noncommunicating rudimentary horn of unicornuate uterus is presented. A healthy female infant weighing 2,985 g was delivered by cesarean section at 37 weeks' gestation. The diagnosis was missed by prenatal ultrasonography and was made only at laparotomy. A retrospective analysis of our ultrasound studies revealed that the echo pattern of the nongravid uterus resembled a soft pelvic mass. Color Doppler imaging revealed prominent low-impedance uterine arcuate-radial arterial blood flow surrounding the periphery of the pelvic mass, as well as multiple areas of placental implantation with a pulsatile lacunar flow pattern. A high index of suspicion of rudimentary horn pregnancy should be borne in mind whenever late-pregnancy ultrasonography shows the above-mentioned characteristic ultrasonic findings.

Interleukin-15 enhances host protection against acute Toxoplasma gondii infection in T-cell receptor alpha-/-deficient mice

A potential role for T-cell receptor (TCR)-gamma(delta) cells in response to Toxoplasma gondii has been described. This study was undertaken to evaluate whether exogenous rIL-15 can enhance the production of gamma(delta) T cells in response to infection with T. gondii. For this, C57BL/6 and TCR alpha-gene deficient mice (alpha-/-) were vaccinated with Toxoplasma lysate antigen (TLA) in combination with interleukin (IL)-15. The cellular and humoral immune response was assessed following immunization. Administration of IL-15/TLA to alpha-/-mice lengthened survival time post lethal challenge. Several immunological parameters were increased in the alpha-/-mice following immunization with IL-15/TLA including serum immunoglobulin (Ig)G1 and IgG2a antibody titres and splenocyte lymphoproliferation in response to parasite antigen. Further, the CTL response to parasite infected target cells as well as the production of interferon gamma was enhanced by IL-15/TLA administration in the alpha-/-mice. These observations indicate that the gamma(delta) T cells response to this parasite can be enhanced by the administration of exogenous IL-15 in the presence of parasite lysate antigen.

The efficacy of potassium citrate based medical prophylaxis for preventing upper urinary tract calculi: a midterm followup study

PURPOSE

We examined the efficacy of potassium citrate based medical prophylaxis for preventing upper urinary calculous recurrence, and compared it with the stone recurrence rate in patients who only received intermittent or no medical prophylaxis.

MATERIALS AND METHODS

We retrospectively reviewed the records of 493 patients with upper urinary calculi, of whom 237 men and 76 women with a mean age of 56.1 and 51.4 years, respectively, were enrolled in the study. Of the 313 participants 64 (group 1, 20.4%) received regular medical prophylaxis for 24 to 42 months (mean 27.8), 80 (group 2, 25.6%) received intermittent medical prophylaxis for 1.5 to 19 months (mean 7.9) and 169 (group 3, 54%) did not receive any medical prophylaxis.

RESULTS

At midterm followup of 24 to 60 months 107 patients (34.2%) had stone recurrence. In group 1 the stone recurrence rate was 7.8%, which was significantly less (p <0.001) than in groups 2 (30%) and 3 (46.2%). Similarly new calculous events in patients with a history of multiple stone recurrence were less frequent in group 1 than in groups 2 and 3 (9.7, 47.4 and 52.2%, respectively, p <0.001). Multiple stone recurrence history, hypercalciuria, hyperuricosuria and calcium oxalate dihydrate calculi were independent risk factors for stone recurrence.

CONCLUSIONS

Regular medical prophylaxis may effectively prevent stone recurrence regardless of previous treatment modalities, stone composition, metabolic abnormalities and stone-free status. Cost effectiveness, patient compliance and gastrointestinal upset may limit patient acceptability and clinical use of medical prophylaxis. However, patients with a history of multiple stone recurrence, calcium oxalate dihydrate stones, hypercalciuria and hyperuricosuria benefit from regular medical prophylaxis.

Diffraction of circularly polarized light from near-field optical probes

Diffracted fields from 100-nm aperture near-field scanning optical microscopy (NSOM) probes and uncoated tapered fibres are measured and analysed. Using a solid angle scanner, the two-dimensional intensity distribution and polarization state of the diffracted light are resolved experimentally. Polarization analyses show that circularly polarized input light does not maintain its polarization state for all diffraction angles, and is completely filtered into linearly polarized light at large polar diffraction angles. This drastic decomposition originates from the vector nature of light diffracted by the sub-wavelength aperture. There is a fundamental difficulty in generating circularly polarized light near the aperture of NSOM probes owing to polarization-dependent diffraction in the near-field regime. This is illustrated by the Bethe-Bouwkamp model using circularly polarized input light.