Heat inactivation can differentiate between IgG and IgM antibodies in the pretransplant cross match

The presence of IgG antibodies in the pretransplant cross-match (XM) test results in hyperacute rejection, but IgM antibodies are inconsequential. The XM should be able to differentiate between IgG and IgM antibodies. This study evaluated 3 methods. This study was based on 500 patients for whom XM were performed between 2004 and 2006 with all 3 techniques. Two patient sera were used: normal serum and heat inactivated serum, which was prepared by incubating patient serum at 63 degrees C for 10 minutes to destroy IgM antibodies. The efficiencies of flow cytometry XM (FC-XM), dithiothreitol complement-dependent microlymphocytotoxicity (DTT/CDC-XM), and heat inactivation (HI-CDC-XM) to differentiate between IgG and IgM were evaluated by using both sera. Patients with positive XM, and negative HI-CDC-XM were reported as negative XM. During the study period, there were 70 patients with positive B-cell XM. Forty-nine became negative after HI-XM, and 21 remained positive. Only 34 cases became negative after DTT-CDC-XM and 36 remained positive. HI-CDC-XM was comparable to FC-XM; all patients testing negative with this technique experienced successful renal transplantations without hyperacute, accelerated, or acute rejection episodes. Our study showed that HI-CDC-XM was effective at exclude donor-specific IgM antibodies, a result which was comparable to FCXM to detect only IgG antibodies. HI is simple and rapid and does not involve any extra equipment or cost.

[Venous interventions--part 1: techniques and lower torso thromboses]

Venous thrombosis is one of the most common vascular diseases. Without treatment, pulmonary embolism is a potentially life-threatening complication. Long-term complications are chronic venous insufficiency and post-thrombotic syndrome. Medical anticoagulation is currently the standard therapy, since it prevents appositional thrombus growth although it usually can not prevent the development of post-thrombotic syndrome. The structure of the thrombotic material often leads to partial recanalisation with residual stenosis. Early and sufficient systemic thrombolysis with adequate concentration may achieve disintegration of the thrombus and preservation of venous valve function. Supplementary to conservative therapy, local catheter thrombolysis is possible even in cases with contraindications for a systemic thrombolysis therapy. Additional interventional techniques reduce the required concentration of the thrombolytic. Venous stenosis can be treated by balloon angioplasty and stent implantation. This article reviews the different percutaneous treatment options as well as their application and usefulness in thrombosis of the lower torso.

[Venous interventions. Part 2: Thromboses of the upper torso and mesenteric veins]

This article focuses on the percutaneous treatment options of venous thromboses and occlusions. Interventional therapy modalities for mediastinal, brachial, axillar, cerebral, and mesenteric thromboses are reviewed. Stenoses of the superior vena cava are most often caused by mediastinal malignomas. Balloon angioplasty together with stent implantation is an effective method for revascularisation in cases of upper venous congestion. Benign central venous stenoses are common in dialysis patients for whom interventional therapy using balloon angioplasty has proven excellent results. In the treatment of insufficient dialysis access, percutaneous techniques represent the first-choice option. Regarding cerebral and mesenteric thrombosis, interventional therapy is restricted to selected individual cases.

Grey water characteristics and treatment options for rural areas in Jordan

Low water consumption in rural areas in Jordan had resulted in the production of concentrated grey water. Average COD, BOD and TSS values were 2568mg/l, 1056mg/l and 845mg/l, respectively. The average grey water generation was measured to be 14L/c.d. Three different treatment options were selected based on certain criterions, and discussed in this article. The examined treatment systems are septic tank followed by intermittent sand filter; septic tank followed by wetlands; and UASB-hybrid reactor. Advantages and disadvantages of each system are presented. It was concluded that UASB-hybrid reactor would be the most suitable treatment option in terms of compactness and simplicity in operation. The volume of UASB-hybrid reactor was calculated to be 0.268m(3) with a surface area of 0.138m(2) for each house having 10 inhabitants on average. Produced effluent is expected to meet Jordanian standards set for reclaimed water reuse in irrigating fruit trees.

Radiological central vein treatment in vascular access

In the last decades, the percutaneous interventional approach for the treatment of central venous obstructions (CVO) has become increasingly popular as the treatment of first choice because of its minimal invasiveness and reported success rates. CVOs are caused by a diverse spectrum of diseases which can be broadly categorized into two principal eliciting genera, either benign or malignant obstructions. The large group of benign venous obstructions includes the increasing number of end-stage renal disease patients with vascular access related complications. Due to the invasiveness and complexity of thoracic surgery for benign CVOs, the less invasive percutaneous interventional therapy can generally be considered the preferred treatment option. Initially, the radiological intervention consisted of balloon angioplasty alone, subsequently additional stent placement was applied. This was advocated as either primary placement or secondary in cases of elastic recoil or residual stenosis after percutaneous transluminal angioplasty (PTA). The efficacy of angioplasty of CVO in patients with vascular accesses, either with or without stenting, has been addressed by various studies. Overall, reports indicate an initial technical and clinical success rate above 95% and satisfactory patency rates. However, systematic follow-up and frequent re-interventions are necessary to maintain vascular patency to achieve long-term success.

Luteinizing hormone pulsatility in patients with major ovarian hyperandrogenism

Hyperandrogenism and ovulatory dysfunction are common in women with either polycystic ovary (PCOS) or ovarian virilizing tumor. However, contrasting with the numerous studies that have extensively described gonadotropin secretory abnormalities, principally increased LH pulse amplitude and frequency, few studies have concerned gonadotropin secretion in patients with ovarian virilizing tumors; low gonadotropin levels have occasionally been reported, but never extensively studied. The goal of the present study was to further evaluate the pulsatility of LH secretion in women with ovarian virilizing tumor compared with that of PCOS patients. Eighteen women with major hyperandrogenism (plasma testosterone level >1.2 ng/ml) were studied (5 women with ovarian virilizing tumor, 13 women with PCOS, and 10 control women). Mean plasma LH level, LH pulse number and amplitude were dramatically low in patients with ovarian tumors when compared to both PCOS (p<0.001) and controls (p<0.001). In case of major hyperandrogenism, LH pulse pattern differs markedly between women with ovarian virilizing tumor or PCOS, suggesting different mechanisms of hypothalamic or pituitary feedback.

Erectile dysfunction in spinal cord-injured men: different treatment options

To evaluate the efficacy, safety and patients' preference of different treatment modalities of ED in men with SCI. Sixty SCI men with ED were included in the study. They were divided into three groups. Group A received sildenafil, group B received intracorporal injection (ICI) and were then shifted to sildenafil and group C used vacuum constriction devices (VCD) and were then shifted to sildenafil. Erection was evaluated before and after each treatment. Ninety percent of patients reported improvement of erection after sildenafil and ICI treatment according to IIEF-EF and only 70% of patients reported improvement in erection with VCD. However, 14 patients reported that they preferred sildenafil due to the easier route of administration. In men with SCI, sildenafil is the most effective treatment and is widely accepted. ICI, VCD therapy in SCI patients should be used according to patient's preference and choice.

The area under the concentration-time curve versus trough and peak blood level monitoring in renal transplant recipients on cyclosporine

OBJECTIVE

The area under the concentration-time curve of cyclosporine microemulsion is the best measure of the absorption and beneficial effects in renal transplant recipients. We sought to determine the best method of monitoring cyclosporine levels in these patients.

METHODS

Prospective evaluation of peak cyclosporine blood levels and area under the curve monitoring were performed for 1 year in 65 renal transplant recipients (study group). Cyclosporine trough levels and peak cyclosporine blood levels were correlated with the calculated area under the curve. Cyclosporine trough levels were monitored in equal numbers of matched controls.

RESULTS

There were no significant differences in the incidence of acute rejection, cyclosporine nephrotoxicity, proteinuria, serum creatinine levels, or graft and patient outcomes between the groups (P = .1). Peak cyclosporine blood levels guided by calculating the area under the curve were found to be 27% to 32% lower than previously reported. The correlation coefficient was <70% for cyclosporine trough levels (P < .02) and >90% for peak cyclosporine blood levels (P < .001) when related to the calculated area under the curve. The calculated area under the curve was approximately 6000 ng/mL/h following transplantation, gradually decreasing to approximately 3000 ng/mL/h at 1 year. Both appeared to the acceptable therapeutic values.

CONCLUSION

Calculating the area under the curve using trough and peak blood levels versus using isolated readings for either of these levels alone is the most effective method of monitoring cyclosporine in recipients undergoing renal transplant.

Results in 158 consecutive cadaveric renal transplantations

OBJECTIVES

We investigated the outcome of deceased donor kidney transplantations performed in a single center in a developing country.

MATERIALS AND METHODS

A total of 158 patients (69 male and 89 female patients, including 32 children) received kidney grafts obtained from deceased donors between March 1996 and October 2004. Cadaveric renal grafts were transplanted after a cold ischemia time of 4 to 24 hours (mean, 12.5 hours). Retransplantation was performed in 19 recipients. Induction immunosuppression was achieved with antithymocyte globulin. The diagnosis of acute graft rejection was based on histopathological findings.

RESULTS

Primary graft function was observed in 77% of cases. Posttransplantation complications were: surgical (n = 60; 38%), systemic bacterial and viral infections (n = 33; 21%), acute rejection (n = 47; 30%), and malignancy (n = 2; 1.3%). Seventeen recipients died with a functioning graft, and 23 more grafts were lost. The 7-year actuarial survival rates were 89% and 75% for recipients and grafts, respectively.

CONCLUSIONS

The kidney transplantation program in Kuwait is steadily growing. Kidney grafts obtained from deceased donors contributed 28% of the transplantation activity and were associated with a high rate of primary function. Overall actuarial recipient and graft survival rates were comparable to those reported by larger centers.

[Ectopic pregnancy with etonogestrel contraceptive implant (Implanon): first case]

We describe the first case of ectopic pregnancy occurring in a patient with an etonogestrel contraceptive implant (Implanon). There was no factor predisposing to a failure of the technique (implant in place for less than 2 years and normal BMI). In addition there was no risk factor for an ectopic location of the pregnancy. We discuss the role of the micro progestative in the location of the pregnancy. This case report emphasizes the fact that ectopic pregnancy should not be ruled out in women taking this contraception, however efficient it is otherwise.

The role of ultrasound biomicroscopy in predicting the result of temporal artery biopsy in temporal arteritis patients: a preliminary study

PURPOSE

Temporal artery biopsy is considered the gold standard for the diagnosis of temporal arteritis (TA). However, complications following this procedure may occur. The goal of this study is to evaluate if ultrasound biomicroscope (UBM) findings are useful in predicting the result (positive or negative) of temporal artery biopsy in patients with TA.

METHODS

Twenty-six consecutive patients with clinical diagnosis of TA seen at the Department of Ophthalmology, Royal Victoria Hospital, Montreal, Canada, were involved in this study. All patients were submitted to UBM before temporal artery biopsy. Eight patients presented histopathologic findings consistent with the diagnosis of TA. Thus, UBM findings of these patients were compared with those from 18 patients with negative biopsy. On UBM we searched for the presence of a hypoechoic effect surrounding the walls of the temporal arteries, the so-called halo sign, as well as an intra-arterial middle reflexive filling, the so-called intra-arterial filling.

RESULTS

The halo sign and/or the intra-arterial filling were found in 8 (100%) of 8 patients with biopsy-proven TA. However, 10 (55.5%) of 18 patients with a negative biopsy presented one or both of these two UBM findings. On the other hand, the absence of these two parameters on the UBM of a patient with TA strongly suggests that the temporal artery biopsy will be negative (negative predictive value=100%).

CONCLUSIONS

This preliminary work suggests that UBM may play a role in predicting a negative result of the temporal artery biopsy in patients with TA. In the present series approximately 30% of the patients could be spared this surgical procedure and its possible complications.

Early Acute Rejection Episodes in Renal Transplantation in Relation to Immunosuppression Protocls: An Audit of 100 Cases

INTRODUCTION

Early acute rejection episodes (ARE) have deleterious effects on graft outcomes. The incidence of ARE in the first 3 months has been reported to be <20%. In a recent audit of ARE among 100 renal transplants, we observed the rates to be high (30%). We retrospectively collected details of donor type, induction therapy, immunosuppression medications, drug levels, HLA mismatches, acute tubular necrosis (ATN), and delayed graft function (DGF) to correlate with ARE and response to therapy.

RESULTS

Thirty rejection episodes occurred after a mean period of 14.3 days after transplantation. Ninety-one patients had induction treatment with either antithymocyte globulin (ATG) or interleukin 2 receptor antibodies (IL2 Rab). The drugs included cyclosporine, mycophenolate, sirolimus, azathioprine, and prednisolone in these patients. There was no significant difference in ARE among the different drug protocols (30.7%-35.2%). Subjects with 4 or more HLA mismatches displayed more ARE (40.3%) compared with those with 3 or less (23%). Subjects with ATN or DGF immediately posttransplantation had a higher incidence of ARE (39.2%) than those without them (26.3%). Deceased donor recipients had a higher episode of ARE (45.1%) compared with live related donor recipients (25%). On stratifying the known risk factors for ARE, subjects with no risk factors had the least (22.2%) ARE compared with those with one (32.5%) or two (47.6%) risk factors. Subjects who failed to achieve adequate cyclosporine (C2) levels showed significantly higher rates of ARE (86.9%) than those with adequate or higher levels (8.6%).

CONCLUSION

Higher HLA mismatches, DGF, deceased donor, and failure to achieve adequate cyclosporine levels were observed to be major risk factors for the development of ARE.

Estrogen-induced abnormal accumulation of fat cells in the rat penis and associated loss of fertility depends upon estrogen exposure during critical period of penile development

We previously reported that diethylstilbestrol (DES) or estradiol valerate (EV) exposure at a dose of 0.10-0.12 mg/kg, or higher, per day, on alternate days, from postnatal days 2-12, resulted in abnormal penis development and infertility (H. O. Goyal et al., 2005, J. Androl. 26, 32-43). The objective of this study was to identify a critical developmental period(s) during which EV exposure results in the observed penile abnormalities. Male pups received EV at a dose of 0.10-0.12 mg/kg on postnatal day(s) 1, 1-3, 4-6, 1-6, 7-12, 13-18, 19-24, or 25-30. Fertility was tested at 102-115 days of age and tissues were examined at 117-137 days. Both penile morphology and fertility were unaltered in rats treated with EV after 12 days of age. Conversely, except in rats treated on postnatal day 1 only, none of the males treated prior to 12 days of age sired pups, and all had abnormal penises, including varying degrees of abnormal accumulation of fat cells and loss of cavernous spaces and smooth muscle cells in the corpora cavernosa penis, which were maximal in the 1-6-day group. Also, the preputial sheath was partially released or its release was delayed, and the weight of the bulbospongiosus muscle was significantly reduced. Plasma testosterone (T) in the 1-6- and 4-6-day groups and intratesticular T in the 4-6-day group were significantly lower. The testosterone surge, characteristic of controls in the first week of life, was suppressed in the 1-3-day group. Estrogen receptor alpha mRNA expression was enhanced in the body of the penis in the 1-3-day group, but not in the 13-18-day group. Hence, EV exposure prior to 12 days of age (as short as 1-3 days postnatal), but not after 12 days of age, results in long-term abnormal penile morphology, characterized by abnormal accumulation of fat cells in the corpora cavernosa penis and, consequently, loss of fertility.

Hemodialysis for patients bleeding or at risk for bleeding, can be simple, safe and efficient

AIM

Hemodialysis for patients bleeding or at risk for bleeding requires special modalities of treatment that are difficult to perform without potential side effects. A simple, safe and adequate method may be applied.

METHODS

A modified way of extracorporeal circuit preparation, which focuses on minimizing the blood-air interface and negligible saline flushing of 50 ml/h, is applied for a maximum of 3-hour session with routine (not one-to-one) nursing attendance. Data from 16,954 sessions performed with patients bleeding or at risk for bleeding (15,730 retrospectively and 1,224 prospectively collected) were analyzed.

RESULTS

Cumulative failure of treatment, as defined by clotting of the extracorporeal circuit requiring termination of the procedure or replacement of the clotted part, was not more than 5% as expected for anticoagulation-free hemodialysis. For the prospectively recorded sessions, blood flow was 234 +/- 30 ml/min with less than 250 ml/min in 42.4% of the sessions. Native blood access was used in 426 (34.8%), double-lumen catheter in 798 (65.2%), 42 were isolated ultrafiltration sessions and 64 blood, 21 plasma, 9 platelet units were transfused. Post/pre urea ratio was 0.50 +/- 0.12. Logistic regression showed that among the following: duration of the session, type of dialysis, ultrafiltration rate, hematocrit, number of platelets, serum total protein, transfusions, blood flow and type of access, only blood flow significantly affected failure incidence (coefficient B = -0.041, exp(B) = 0.96, p = 0.04). No complications due to treatment were noted.

CONCLUSION

In patients with active, or at risk for, bleeding, hemodialysis without systemic anticoagulation can be adequately and safely performed almost as a routine session.

Bilateral and synchronous cervical carcinoma in situ in a didelphic uterus

A case is reported of a bilateral and synchronous cervical squamous cell carcinoma in situ in a patient with uterus didelphys. Bilateral simultaneous conizations of both cervices were curative. Theories of tumor origin in such a case are discussed.

Abnormal Morphology of the Penis in Male Rats Exposed Neonatally to Diethylstilbestrol Is Associated with Altered Profile of Estrogen Receptor-α Protein, but Not of Androgen Receptor Protein: A Developmental and Immunocytochemical Study1

Objectives of the study were to determine developmental changes in morphology and expression of androgen receptor (AR) and estrogen receptor (ER)alpha in the body of the rat penis exposed neonatally to diethylstilbestrol (DES). Male pups received DES at a dose of 10 microg per rat on alternate days from Postnatal Day 2 to Postnatal Day 12. Controls received olive oil vehicle only. Tissue samples were collected on Days 18 (prepuberty), 41 (puberty), and 120 (adult) of age. DES-induced abnormalities were evident at 18 days of age and included smaller, lighter, and thinner penis, loss of cavernous spaces and associated smooth muscle cells, and increased deposition of fat cells in the corpora cavernosa penis. Fat cells virtually filled the entire area of the corpora cavernosa at puberty and adulthood. Plasma testosterone (T) was reduced to an undetectable level, while LH was unaltered in all treated groups. AR-positive cells were ubiquitous and their profile (incidence and staining intensity) did not differ between control and treated rats of the respective age groups. Conversely, ERalpha-positive cells were limited to the stroma of corpus spongiosus in all age groups of both control and treated rats, but the expression in treated rats at 18 days was up-regulated in stromal cells of corpora cavernosa, coincident with the presence of morphological abnormalities. Hence, this study reports for the first time DES-induced developmental, morphological abnormalities in the body of the penis and suggests that these abnormalities may have resulted from decreased T and/or overexpression of ERalpha.

Prévalence des sténoses des artères rénales dépistées au cours de coronarographies diagnostiques : dans quels cas doit-on réaliser une aortographie abdominale ?

PURPOSE

To define a subgroup of patients at increased risk of renal artery stenosis (RAS) in a population of patients undergoing cardiac catheterization.

MATERIALS AND METHODS

A total of 467 patients (mean age of 64 Years +/-11) underwent cardiac catheterization and aortography Results were evaluated to detect correlations between the presence or absence of RAS and clinical and biological parameters.

RESULTS

A total of 42 (9%) patients had a renal artery stenosis. Univariate analysis defined parameters correlated with the presence of RAS: systolic blood pressure (p=0.03), pulse pressure (p=0.005), age (p<0.0001), creatinine clearance (p<0.0001), 2-vessel (p=0.028) and 3-vessel (p=0.037) coronary artery diseases. Multivariate analysis showed that the presence of RAS correlated to creatinine clearance (p=0.02) and 2-vessel coronary artery disease. A creatinine clearance between 30 and 60 ml/min and multi-vessel coronary artery disease defined a subgroup at increased risk of RAS with sensitivity, specificity, positive and negative predictive values of: 47.6, 90.1, 32.3 and 94.6%. The prevalence of renal artery stenosis was 5.2% when both parameters were absent.

CONCLUSION

Patients with mild renal insufficiency and multi-vessel coronary artery disease defined a subgroup of patients at increased risk of RAS (32.5%) that may benefit from abdominal aortography performed at the time of cardiac catheterization.

Ultrasound biomicroscopic evaluation of the traumatized eyes

PURPOSE

To review causes for performing an ultrasound biomicroscopic (UBM) examination in traumatized eyes, to present common UBM findings of 109 eyes with a history of ocular trauma and to compare these findings according to the type of the trauma.

MATERIALS AND METHODS

A total of 109 eyes with a history of mechanical ocular trauma, which underwent an UBM examination between December 1996 and April 2002, were evaluated retrospectively. All cases were classified according to the criteria of the Ocular Trauma Classification Group and UBM findings were reviewed. For statistical ana- lyses, chi(2) test and Fisher's exact test were used.

RESULTS

UBM examinations were performed for the evaluation of the zonules before cataract surgery (49.5%), examination of the anterior segment in the presence of media opacities (32.1%), detection of suspected ocular foreign bodies (10.1%) and the evaluation of ocular hypotony (8.3%). In all, 67 eyes (61.5%) had a closed-globe injury, whereas 42 (38.5%) had an open-globe injury. The most common UBM findings in a closed-globe injury were zonular deficiency (64.2%), angle recession (43.3%), iridodialysis (17.9%), and dislocated lens (16.4%). The most common UBM findings in an open-globe injury were zonular deficiency (54.8%), iridodialysis (26.2%), peripheral anterior synechiae (PAS) (26.2%), and iridocorneal adhesion (19%). Among the common UBM findings, the angle recession was significantly higher (P<0.001) in closed-globe injury group and PAS formation was significantly higher (P<0.05) in open-globe injury group.

CONCLUSIONS

UBM is particularly superior to other methods in the evaluation of the zonular status, angle recession, cyclodialysis, and the detection of small superficial and intraocular foreign bodies.

Maximum intensity projection analysis in magnetic resonance of the breast

The aim of this study was to determine the sensitivity, specificity and accuracy of vascular asymmetries and vessel location seen using MR Maximum Intensity Projection imaging for malignant and benign lesions. We enrolled 101 women, with an age ranging from 29 to 69 years (mean age of 53.1 years), with a mammary nodule and candidate for surgical intervention. MR was carried out using a 1.5 Tesla superconductive magnet, equipped with a double and bilateral Phased Array dedicated coil. All images obtained were processed using MIP. The relationship between an asymmetry due to a greater amount of vascular structures in the breast with a malignant neoplasm and symmetry with benign neoplasms were statistically significant (p < 0.001): sensitivity of 71.8%, specificity 100% and accuracy 76.2%. The relationship between perilesional or intralesional vessels with malignant versus benign neoplasms were statistically significant (p < 0.001): sensitivity 88.5%, specificity 82.6% and accuracy 87.1%. We concluded that asymmetries between breasts and the presence of perilesional or intralesional vessels seen in MIP images are important signs and, therefore, must be reported.

Ultrasound biomicroscopy of sclerotomy sites: the effect of vitreous shaving around sclerotomy sites during pars plana vitrectomy

PURPOSE

To study the difference in the amount of vitreous incarceration between conventional pars plana vitrectomy (PPV) and PPV with vitreous shaving around sclerotomy sites.

METHODS

A dynamic in vivo examination using ultrasound biomicroscopy (UBM) was performed on the sclerotomy sites of 22 eyes after PPV. Patients were divided into two groups. In the study group (n = 11), the vitreous was completely shaved from the internal initial sclerotomy by cotton-tip depressed vitrectomy under coaxial illumination. In the control group (n = 11), no vitreous shaving was performed.

RESULTS

Vitreous incarceration into sclerotomy sites was significantly less in the study group compared with the control group (P <0.001). No difference was seen among the three sclerotomy sites regarding vitreous incarceration within individual eyes. No difference was seen between eyes operated by right- and left-handed surgeons.

CONCLUSIONS

Vitreous shaving of sclerotomy sites using depressed vitrectomy significantly reduces vitreous incarceration. This may reduce the rate of sclerotomy-related complications following PPV in selected cases.

Heteromeric AMPA receptors assemble with a preferred subunit stoichiometry and spatial arrangement

AMPA receptors are thought to be a tetrameric assembly of the subunits GluR1-4. We have examined whether two coexpressed subunits (GluR1/2) combine at random to form channels, or preferentially assemble with a specific stoichiometry and spatial configuration. The subunits carried markers controlling ion permeation and desensitization, and these properties were monitored as a function of relative expression level and subunit composition. Homomeric receptors assembled stochastically while heteromeric receptors preferentially formed with a stoichiometry of two GluR1 and two GluR2 subunits, and with identical subunits positioned on opposite sides of the channel pore. This structure will predominate if GluR1 binds to GluR2 more rapidly during receptor assembly than other subunit combinations. The practical outcome of selective heteromeric assembly is a more homogenous receptor population in vivo.

Management of hydrocephalus in pediatric patients with posterior fossa tumors: the role of endoscopic third ventriculostomy

OBJECT

The authors undertook a study to evaluate the effectiveness of endoscopic third ventriculostomy in the management of hydrocephalus before and after surgical intervention for posterior fossa tumors in children.

METHODS

Between October 1, 1993, and December 31, 1997, a total of 206 consecutive children with posterior fossa tumors underwent surgery at Hĵpital Necker-Enfants Malades in Paris. Excluded were 10 patients in whom shunts had been placed at the referring hospital. The medical records and neuroimaging studies of the remaining 196 patients were reviewed and categorized into three groups: Group A, 67 patients with hydrocephalus present on admission in whom endoscopic third ventriculostomy was performed prior to tumor removal; Group B, 82 patients with hydrocephalus who did not undergo preliminary third ventriculostomy but instead received conventional treatment; and Group C, 47 patients in whom no ventricular dilation was present on admission. There were no significant differences between patients in Group A or B with respect to the following variables: age at presentation, evidence of metastatic disease, extent of tumor resection, or follow-up duration. In patients in Group A, however, more severe hydrocephalus was demonstrated (p < 0.01): the patients in Group C were in this respect different from those in the other two groups. Ultimately, there were only four patients (6%) in Group A compared with 22 patients (26.8%) in Group B (p = 0.001) in whom progressive hydrocephalus required treatment following removal of the posterior fossa tumor. Sixteen patients (20%) in Group B underwent insertion of a ventriculoperitoneal shunt, which is similar to the incidence reported in the literature and significantly different from that demonstrated in Group A (p < 0.016). The other six patients (7.3%) were treated by endoscopic third ventriculostomy after tumor resection. In Group C, two patients (4.3%) with postoperative hydrocephalus underwent endoscopic third ventriculostomy. In three patients who required placement of CSF shunts several episodes of shunt malfunction occurred that were ultimately managed by endoscopic third ventriculostomy and definitive removal of the shunt. There were no deaths; however, there were four cases of transient morbidity associated with third ventriculostomy.

CONCLUSIONS

Third ventriculostomy is feasible even in the presence of posterior fossa tumors (including brainstem tumors). When performed prior to posterior fossa surgery, it significantly reduces the incidence of postoperative hydrocephalus. The procedure provides a valid alternative to placement of a permanent shunt in cases in which hydrocephalus develops following posterior fossa surgery, and it may negate the need for the shunt in cases in which the shunt malfunctions. Furthermore, in patients in whom CSF has caused spread of the tumor at presentation, third ventriculostomy allows chemotherapy to be undertaken prior to tumor excision by controlling hydrocephalus. Although the authors acknowledge that the routine application of third ventriculostomy in selected patients results in a proportion of patients undergoing an "unnecessary" procedure, they believe that because patients' postoperative courses are less complicated and because the incidence of morbidity is low and the success rate is high in those patients with severe hydrocephalus that further investigation of this protocol is warranted.

A side-by-side comparison of sampling methods for settled, indoor allergens

Exposure to indoor allergens is associated with asthma, but there is no standardized sampling method for measuring allergens. We compared the association of measured allergen exposure and serum-specific IgE levels and the precision of three sampling methods (Cyclone, Mighty Mite, and Readivac II) to identify a standardized sampling method for indoor allergens. A random sample of 72 children, 5 to 17 years old, with doctor-diagnosed asthma who lived in the same residence >or=2 years were enrolled. Composite, side by side floor samples were obtained with all three methods. Dust allergen concentrations and serum-specific IgE levels were measured for Der f I, Fel d I, and Bla g I. Mean allergen concentration did not differ significantly by sampling method. Cat allergen was significantly correlated with serum-specific IgE for Cyclone (P=0.003) and Mighty Mite (P=0.008), but only marginally for Readivac II (P=0.07). Dust mite allergen was significantly correlated with serum-specific IgE for Readivac II (P=0.02) and Cyclone (P=0.038), but not for Mighty Mite (P=0.12). Cockroach allergen was not correlated with serum-specific IgE for any sampling method. In multiple linear regression, cat allergen was associated with serum-specific IgE for Cyclone (P=0.007) and Mighty Mite (P=0.02), but not for Readivac II (P=0.06). In contrast, dust mite allergen was marginally associated with serum-specific IgE for Readivac II (P=0.07), but not for Mighty Mite (P=0.64) or Cyclone (P=0.27). The Cyclone and Mighty Mite were more precise than Readivac II for cat allergen, but there was no difference for dust mite allergen (P>0.05). No single method is superior for measurement of indoor allergens. In general, cat allergen collected with the Cyclone was a better predictor of serum-specific IgE levels to Fel d I, whereas dust mite allergen collected with the Readivac II was a better predictor of serum-specific IgE levels to Der f I.

Mild thickening of the aortic wall: subtle intramural hematoma?

Recently published criteria for the diagnosis of intramural hematoma (IMH) of the ascending aorta by transesophageal echocardiogram (TEE) include the presence of a crescent-shaped thickening of the aortic wall of more than 7 mm with an echolucent space. We report a patient whose clinical presentation suggested aortic dissection but whose TEE failed to meet the conventional criteria for such a diagnosis. TEE showed a uniform intimal thickening suspicious of IMH but less than 7 mm in thickness and with no echofree space. One week later, the patient developed frank aortic dissection.

CONCLUSION

IMH can present with a subtle echo appearance. The diagnosis should not be totally discounted in the absence of a 7-mm crescentic wall thickness and an echofree space if the clinical presentation is suggestive of dissection.

Predicting sulcus size using ocular measurements

PURPOSE

To predict sulcus size using ocular measurements.

SETTING

Michel Pop Clinics, Montreal, Quebec, Canada.

METHODS

Forty-three eyes were evaluated using several techniques. Ultrasound biomicroscopy (UBM) echograms were taken to measure the anterior chamber depth (ACD), sulcus size, and central corneal thickness. The limbus size was measured with a caliper. Axial length, ACD, and pachymetry were measured by contact ultrasonography. Refraction and corneal power were also evaluated.

RESULTS

The coefficient of linear regression was 0.05 between the limbus and the sulcus size (P =.78), 0.76 between ultrasonography and UBM ACD measurements (P <.001), and 0.69 between ultrasonography and UBM pachymetry (P <.001). Paired t tests showed that ultrasound and UBM ACD measurements were not statistically different (P =.70) but that ultrasound and UBM pachymetry measurements were (P <.001). The sulcus versus limbus difference was 0.6 mm for myopia and 0.3 mm for hyperopia. A backward elimination multiple regression performed with all measures to predict sulcus size resulted in the following formula: Sulcus size = 18.9 - 0.023 x sphere + 0.15 x mean keratometry (R = 0.49; P =.005; statistical power = 0.89; standard error of estimate = 0.5 mm).

CONCLUSION

Traditional estimation of sulcus size through limbal measurement is inadequate because limbus size alone cannot predict sulcus size. A general formula using the sphere and the mean corneal power can help predict sulcus size. Corneal power was significantly and negatively correlated with sulcus and limbus size as well as sphere. The standard error of sulcus measurement by UBM was 0.4 mm.

TNF-alpha and homocysteine levels in type 1 diabetes mellitus

The role of homocysteine as an independent risk factor for vascular endothelial damage, and the possible link between homocysteine and tumour necrosis factor-alpha (TNF-alpha) as two synergistic risk factors for beta-cell apoptosis in type 1 diabetes mellitus was studied. Plasma homocysteine levels were significantly elevated in all diabetic patients compared with controls and diabetic patients with vascular complications showed higher elevations. Furthermore, homocysteine levels showed significant positive correlation with the degree of microalbuminuria. TNF-alpha levels were elevated in all diabetic patients compared with controls. These results may have therapeutic implications.

Application of coupled liquid chromatography-mass spectrometry in photolysis studies of the herbicide triflusulfuron-methyl

The photochemical fate of the herbicide triflusulfuron-methyl in aqueous solution under UV light (lambda > 290 nm) was investigated. Nine photoproducts were detected and tentatively identified by LC/MS and LC/MS/MS analysis. The main routes of degradation involve the cleavage and/or contraction of the sulfonylurea bridge with the elimination of sulfur dioxide, which increases the acidity of the reaction medium. On the basis of the results obtained a photodegradation pathway is proposed.

Left-to-right gradient of atrial frequencies during acute atrial fibrillation in the isolated sheep heart

BACKGROUND

Recent studies demonstrated spatiotemporal organization in atrial fibrillation (AF). We hypothesized that waves emanating from sources in the left atrium (LA) undergo fragmentation, resulting in left-to-right frequency gradient. Our objective was to characterize impulse propagation across Bachmann's bundle (BB) and the inferoposterior pathway (IPP) during AF.

METHODS AND RESULTS

In 13 Langendorff-perfused sheep hearts, AF was induced in the presence of acetylcholine (ACh). Fast Fourier transform of optical and bipolar electrode recordings was performed. Frequency-dependent changes in the left-to-right dominant frequency (DF) gradient were studied by perfusing D600 (2 micromol/L) and by increasing ACh concentration from 0.2 to 0.5 micromol/L. BB and IPP were subsequently ablated. At baseline, a left-to-right decrease in DFs occurred along BB and IPP, resulting in an LA-right atrium (RA) frequency gradient of 5.7+/-1.4 HZ: Left-to-right impulse propagation was present in 81+/-5% and 80+/-10% of cases along BB and IPP, respectively. D600 decreased the highest LA frequency from 19.7+/-4.4 to 16.2+/-3.9 Hz (P<0.01) and raised RA DF from 8.6+/-2.0 to 10.7+/-1.8 Hz (P<0.05). An increase in ACh concentration increased the LA-RA frequency gradient from 4.9+/-1.8 to 8.9+/-1.8 Hz (P<0.05). Ablation of BB and IPP decreased RA DF from 10.9+/-1.2 to 9.0+/-1.5 Hz (P<0.01) without affecting LA DF (16.8+/-1.5 versus 16.9+/-1.8 Hz, P=NS).

CONCLUSIONS

Left-to-right impulse propagation and frequency-dependent changes in the LA-RA frequency gradient during AF strongly support the hypothesis that this arrhythmia is the result of high-frequency periodic sources in the LA, with fibrillatory conduction away from such sources.

Neural networks studies: quantitative structure-activity relationships of antifungal 1

Models of relationships between structure and antifungal activity of 1-[2-(substituted phenyl)allyl]imidazoles and related compounds were constructed by means of a multilayer neural network using the back-propagation (BP) algorithm. Each molecule was described by three structural and one physicochemical parameters. The leave-one-out procedure was used to assess the predictive ability of a neural network model. The results obtained were compared to those given in the literature by the multiple linear regression (MLR), and were found to be better. The contribution of each descriptor to the structure-activity relationships was evaluated. Hydrophobicity of the molecule was confirmed to take the most relevant part in the molecular description.

Diethylstilbestrol-treated adult rats with altered epididymal sperm numbers and sperm motility parameters, but without alterations in sperm production and sperm morphology

In this study, we characterized estrogenic effects of diethylstilbestrol (DES) on reproductive parameters in male rats to identify a minimal dose level that alters epididymal and sperm functions but has little or no effect on sperm production and/or spermatogenesis. Adult rats (five animals/group) received s.c. injections of 0.2 ml of corn oil containing DES at a rate of 1.0 mg, 200 microg, 40 microg, 8 microg, 1.6 microg, or 320 ng x rat(-1) x day(-1) for 12 days. The control group received corn oil only. DES effects were similar in the 8-microg group and higher dose groups and included significant (P < or = 0.05) reductions in 1) absolute and relative weights of the head and body of the epididymis (EP), tail of the EP, and seminal vesicle, 2) numbers of sperm in both regions of the EP, and 3) motility characteristics in sperm collected from the tail of the EP. Conversely, no significant changes were observed in relative testis weight, daily sperm production, spermatogenesis, seminiferous epithelial height in stage VII, and sperm morphology. All of the above parameters in the 1.6-microg group (except seminal vesicle weight) and 320-ng group were comparable to those of controls. Plasma testosterone (T) level was reduced to an almost undetectable level in the > or = 8-microg groups and to a very low level in the 1.6-microg group (0.35 vs. 2.36 ng/ml in controls or 320-ng group), but LH level was unaltered. In a parallel fertility study, males received DES at a rate of 40, 8, or 1.6 microg x rat(-1) x day(-1) for 12 days prior to and 12 days during cohabitation (1:1) with untreated females. Of the 15 females cohabited with treated males (5 females/dose), none in the 40-microg and 8-microg groups and 1 in the 1.6-microg group formed a copulatory plug and delivered 8 pups, in contrast to 5/5 copulatory plugs and 13-15 pups/litter in the controls. DES at a rate of 8 microg x rat(-1) x day(-1) for 12 days reduced EP weights, sperm numbers in the EP, and sperm motility patterns but caused minimal to no alterations in daily sperm production, spermatogenesis, or sperm morphology. Factors other than T, or in addition to lower T, may be responsible for DES-induced reproductive disorders (despite lower T, sperm contents and sperm motility patterns in the EP were normal in the 1.6-microg group). Deficits in EP sperm functions and/or sexual behavior (as evident from absence of copulatory plugs) probably accounted for reduced fertility in treated males.

Complexins regulate a late step in Ca2+-dependent neurotransmitter release

Synaptic vesicle fusion at synapses is triggered by increases in cytosolic Ca2+ levels. However, the identity of the Ca2+ sensor and the transduction mechanism of the Ca2+ trigger are unknown. We show that Complexins, stoichiometric components of the exocytotic core complex, are important regulators of transmitter release at a step immediately preceding vesicle fusion. Neurons lacking Complexins show a dramatically reduced transmitter release efficiency due to decreased Ca2+ sensitivity of the synaptic secretion process. Analyses of mutant neurons demonstrate that Complexins are acting at or following the Ca2+-triggering step of fast synchronous transmitter release by regulating the exocytotic Ca2+ sensor, its interaction with the core complex fusion machinery, or the efficiency of the fusion apparatus itself.

Uveal effusion after cataract surgery: an echographic study

PURPOSE

To determine the incidence of uveal effusion after cataract surgery and to relate its presence to selected preoperative, intraoperative, and postoperative variables.

DESIGN

Prospective consecutive observational case series.

PARTICIPANTS

Two hundred seven eyes of 205 subjects undergoing cataract surgery.

METHODS

Several preoperative, intraoperative, and postoperative variables of potential significance in uveal effusion after cataract surgery were studied. On the first postoperative day and within 2 weeks after the surgery, subjects were examined clinically and echographically with B-scan for evidence of suprachoroidal (uveal) effusion. When effusion was present, follow-up examinations were performed until complete resolution was documented.

MAIN OUTCOME MEASURES

Echographic presence of uveal effusion in the postoperative period.

RESULTS

Uveal effusion was documented echographically in 12 patients (5.8%). Only one of these cases was clinically evident. All effusions were small and resolved with no intervention. The presence of postoperative hypotony related to wound leak (intraocular pressure <10 mmHg) was significantly correlated with uveal effusion after cataract surgery (P<0.0001). The combination of oral acetazolamide and topical pilocarpine gel given after the surgery also correlated with effusion (P<0.02). Intraoperative complications and prolonged phacoemulsification time were not shown to be risk factors for effusion.

CONCLUSIONS

Uveal effusion is rarely seen after modern, small-incision, closed-system cataract surgery. It is correlated with postoperative hypotony related to wound leak and with the administration of both oral acetazolamide and topical pilocarpine after surgery.

NMDA receptor mediated changes in IGF-II gene expression in the rat brain after injury and the possible role of nitric oxide

This study was undertaken in order to investigate the role of insulin-like growth factor (IGF)-II, c-fos, N-methyl-D-aspartate (NMDA) receptors, and nNOS in the cellular processes following a penetrating brain injury. IGF-II mRNA levels, as determined by Northern analysis, were decreased at 4, 8, and 24 h after brain injury, in the lesioned, compared to the contralateral intact hemisphere. Forty-eight and 72 h after the injury, there was no difference between the lesioned and the contralateral intact hemisphere in IGF-II mRNA levels. c-fos mRNA levels followed a parallel, but opposite course: They were increased at 4, 8 and 24 h after the injury, while at 48 and 72 h c-fos mRNA levels in the lesioned hemisphere did not differ from those in the intact. Administration of MK-801 reversed the injury-induced decrease in IGF-II mRNA levels. Administration of MK-801 resulted in an increase in IGF-II mRNA in both the intact and the lesioned hemispheres. Brain injury resulted in an increase in nNOS immunopositive cells in the hippocampal formation, which was detectable at 4 and 12, but not 48 h after the injury. These results suggest that IGF-II, c-fos, NMDA receptors and nNOS are involved in the cellular responses to brain injury.

Effects of captopril on interleukin-6, leukotriene B(4), and oxidative stress markers in serum and inflammatory exudate of arthritic rats: evidence of antiinflammatory activity

We previously demonstrated that captopril (CP) exhibited a high ability to inhibit enzymatically generated leukotrienes, particularly LTB(4), from stimulated intact human neutrophils. This finding together with the immunosuppressive effect of CP have proposed a possible antiinflammatory activity for the drug. Thus, the present study was conducted to investigate the effect of CP on immunologically mediated chronic inflammation; two models were chosen, namely, Freund's adjuvant arthritis and mixed-type hypersensitivity in rat. The effect of CP was assessed on the basis of physical parameter (paw edema) and biochemical markers in blood and inflammatory exudate. CP was given daily during the course of inflammation development. It was administered ip at three doses, viz. 1, 10, and 100 mg/kg. The results claimed that CP succeeded in suppressing edema evolution in hind paws of Freund's arthritic animals, during all phases of the disease. During the chronic phase of inflammation, in either model, CP reduced the elevated serum and exudate (local) LTB(4) and IL-6 levels. The effect on LTB(4) was more pronounced in the exudate and tended to be dose-related. The antiarthritic effect of CP was also accompanied by augmentation of serum level of protein thiols, with reduction or normalization of elevated systemic and/or local levels of lipid peroxide, superoxide dismutase, and glutathione. It could be concluded that long-term treatment with CP confers a good antiinflammatory activity against arthritis in rat, leading to improvement of the oxidative stress induced by the arthritic insult. The reparative effect of the drug could be mediated via reduction of LTB(4) and IL-6.

Spatially distributed dominant excitation frequencies reveal hidden organization in atrial fibrillation in the Langendorff-perfused sheep heart

INTRODUCTION

Atrial fibrillation (AF) is characterized by complex wave propagation, yet periodic excitation suggesting a high degree of organization may be revealed during sustained AF. We provide a systematic quantification of the spatial distribution of dominant frequencies (DFs) of local excitation on the epicardium of the right atrial (RA) free wall and left atrial (LA) appendage of the isolated sheep heart during AF. The data reveal, for the first time, hidden organization, independent of the activation sequences or nature of electrograms.

METHODS AND RESULTS

In 13 Langendorff-perfused sheep hearts, AF was induced in presence of 0.1 to 0.6 microM acetylcholine. Video movies (potentiometric dye di-4-ANEPPS) of the RA and LA (>30,000 and >20,000 pixels, respectively) were obtained at 120 frames/sec and a biatrial electrogram was recorded. Spectral analyses were performed on movies with DF maps constructed. During AF, the activity formed stable discrete domains with uniform DFs within each domain. Acceleration of AF increased the number of domains (R = 0.81, P < 0.0001) and the DF variance (R = 0.63, P < 0.001), indicating a decrease in organization. Also, the LA was faster and more homogeneous, with smaller number of DF domains, compared to the RA (P < 0.00001).

CONCLUSION

In this model, AF is characterized by multiple domains with distinct DFs on the atrial epicardium. The decrease in domain area with increased rate suggests that AF results from high-frequency impulses that undergo spectral transformations. The LA is generally faster and more organized than the RA, suggesting that the sources for the impulses are localized to the LA.

B2-1, a Sec7- and pleckstrin homology domain-containing protein, localizes to the Golgi complex

B2-1 is a human protein that contains both a Sec7 and a pleckstrin homology domain. The yeast Sec7 protein was previously shown to be involved in vesicle formation in the Golgi and endoplasmic reticulum. Recently, several groups have shown that B2-1 and highly similar proteins (e.g., ARNO, ARNO3) have varied cellular functions and subcellular locations. One of these is an association of the B2-1 Sec7 domain with the plasma membrane, binding to the cytoplasmic portion of the integrin beta2 chain (CD18) and is postulated to be involved in inside-out signaling. Other groups have shown that B2-1 and these related proteins are guanine nucleotide-exchange factors that act upon ADP ribosylation factors (ARFs) and are localized to the Golgi or plasma membrane. Here we report the subcellular localization of B2-1 protein. Interestingly, B2-1 does not localize to the plasma membrane but rather associates with a distinct Golgi complex compartment. B2-1's distribution can be disrupted by brefeldin A, a drug that rapidly disrupts the Golgi apparatus by inhibiting ARF activity. Furthermore, transient transfection of GFP-tagged B2-1 shows Golgi complex targeting. Excessive overexpression of transfected B2-1 causes partial Golgi dispersion.

Inhibition of calcium ionophore-stimulated leukotriene generation from intact human neutrophils by captopril

Effects of captopril on the formation of leukotrienes (LTs) from stimulated intact human neutrophils were investigated. Neutrophils were stimulated with 1 microM calcium ionophore A23187 for the generation of LTs. A reverse phase high performance liquid chromatography technique and UV spectroscopy were used to detect and quantitate the released LTs namely, LTB4. LTC4. delta6-trans-LTB4 and delta6-trans-12-epi-LTB4. Preincubation of neutrophils with captopril significantly reduced LTB4 formation in a concentration-dependent manner, as compared to diluent-treated control cells. Since LTA4 is the substrate for both LTB4 and LTC4, thus in presence of captopril, shunting of LTA4 from synthesis of LTB4 was not directed to LTC4 formation. This finding was evidenced by the significant decrease of LTC4 production under the influence of high concentration of the drug. Formation of LTB4 stereoisomers, delta6-trans-LTB4 and delta6-trans-12-epi-LTB4 was not markedly altered by captopril. In subsequent experiments, when neutrophils were stimulated with A23187 after preincubation with exogenous arachidonic acid (75 microM), and treatment with captopril, similar findings were obtained for LTB4 and LTC4. Meanwhile, formation of the nonenzymatic hydrolysis products of LTA4 tended to rise reaching significant level in case of delta6-trans-LTB4, at the high concentration of captopril. These results demonstrate that captopril is an inhibitor of enzymatically generated LTs produced by intact human neutrophils, being more potent against LTB4. These effects of captopril on LTs are not mediated via an inhibition of arachidonic acid formation from membrane phospholipids. It could be suggested that captopril, at doses used clinically. could inhibit the generation of LTB4 without affecting LTC4. Consequently, these findings might account for possible antiinflammatory activity for captopril, and further suggest that some of the observed side effects of captopril might not be related to an overproduction of LTC4.

Inhibitory combinations of nisin, sodium chloride, and pH on Listeria monocytogenes ATCC 15313 in broth by an experimental design approach

The influence of pH (5.0-8.2), NaCl concentrations (0-6% w/v), and incubation time (0-24 h) on the inhibitory activity of nisin (0-100 I.U./ml) against Listeria monocytogenes (10(3) cfu/ml) was studied using the Doehlert experimental design and was confirmed by kinetic experiments. Predicted values were in agreement with experimental values. Experiments were carried out at 22 degrees C in reconstituted TSB-YE1 broth with or without NaCl. Nisin had an immediate pH-dependent bactericidal effect, which increased with decreasing pH values. In modified TSB-YE1 broth without NaCl, the bactericidal efficacy of nisin (50 I.U./ml) was maximum at pH 6.6, with no L. monocytogenes survivors until 120 h at 22 degrees C. Nisin (50 I.U./ml) action decreased in the presence of NaCl, with a minimal inhibitory effect between 2 and 4%. This partially protective effect was cancelled at higher levels of nisin.