Early postnatal development of rat brain: in vivo diffusion tensor imaging

Perinatal hypoxia is a major cause of neurodevelopmental deficits. Neuronal migration patterns are particularly sensitive to perinatal hypoxia/ischemia and are associated with the clinical deficits. The rat model of hypoxia/ischemia at P7 mimics that of perinatal injury in humans. Before assessing the effects of postnatal injury on brain development, it is essential to determine the normal developmental trajectories of various brain structures in individual animals. In vivo longitudinal diffusion tensor imaging (DTI) was performed from postnatal day 0 (P0) to P56 on Wistar rats. The DTI metrics, mean diffusivity (MD), fractional anisotropy (FA), axial (lambdal) and radial (lambdat) diffusivities, were determined for four gray matter and eight white matter structures. The FA of the cortical plate and the body of corpus callosum decreased significantly during the first 3 weeks after birth. The decrease in the cortical plate's FA value was associated mainly with an increase in lambdat. The initial decrease in FA of corpus callosum was associated with a significant decrease in lambdal. The FA of corpus callosum increased during the rest of the observational period, which was mainly associated with a decrease in lambdat. The FA of gray matter structures, hippocampus, caudate putamen, and cortical mantle did not show significant changes between P0 and P56. In contrast, the majority of white matter structures showed significant changes between P0 and P56. These temporal changes in the DTI metrics were related to the neuronal and axonal pruning and myelination that are known to occur in the developing brain.

Three-dimensional ultrasound and three-dimensional power Doppler in the assessment of ovarian tumors

OBJECTIVE

To determine preoperative method that predicts nature of ovarian tumors.

METHODS

Fifty patients with complex pelvic masses assessed preoperatively with two-dimensional ultrasound (2DUS), two-dimensional power Doppler (2DPD), three-dimensional ultrasound (3DUS), three-dimensional power Doppler (3DPD), color Doppler.

RESULTS

All patients underwent exploration, 19 (38%) had benign tumors, 31 (62%) had ovarian cancer. 2DUS identified 29 cases suspicious for malignancy giving sensitivity, specificity, PPV and accuracy of 80%, 78%, 86%, and 80%. 2DUS with 2DPD identified 28 suspicious cases giving sensitivity, specificity, PPV and accuracy of 80%, 84%, 89%, and 82%. 3DUS identified 31 suspicious cases including 28 cancers giving sensitivity, specificity, PPV and accuracy of 90%, 84%, 90%, and 88%. 3DUS with 3DPD, identified 34 suspicious cases including all 31 cancers giving sensitivity, specificity, PPV and accuracy of 100%, 84%, 91%, and 94%. Color Doppler RI of 0.48 identified 28 cases of 31 cancers giving sensitivity of 90%.

CONCLUSION

Evaluation by 3DUS with 3DPD improves diagnostic accuracy of ovarian tumors.

Gene therapy of uterine leiomyoma: adenovirus-mediated herpes simplex virus thymidine kinase/ganciclovir treatment inhibits growth of human and rat leiomyoma cells in vitro and in a nude mouse model

Uterine leiomyomas (LM) affect a high percentage of reproductive-age women. They develop as discrete, well-defined tumors that are easily accessible with imaging techniques--making this disease ideal for localized gene therapy approaches. In this study, we determined the efficacy of adenovirus-mediated herpes simplex virus thymidine kinase gene transfer in combination with ganciclovir (Ad-TK/GCV) as a potential therapy for LM. Rat ELT-3 LM cells and human LM cells were transfected with different multiplicity of infections (10-100 plaque forming units [PFU]/cell) of Ad-TK and treated with GCV (5, 10, or 20 microg/ml) for 5 days. To test the bystander effect, Ad-TK-transfected ELT-3 cells (100 PFU/cell) or LM cells (10 PFU/cell) were cocultured with corresponding nontransfected cells at increasing percentages and treated with GCV followed by cell counting. In ELT-3 cells transfected with Ad-TK/GCV (10, 20, 50, or 100 PFU/cell), the cell count was reduced by 24, 42, 77, and 87%, respectively, compared with the control cells (transfected with Ad-Lac Z/GCV). Similarly, in LM cells transfected with Ad-TK/GCV (10, 50, or 100 PFU/cell), the cell count was reduced by 31, 62, and 82%, respectively, compared with the control. A strong bystander effect was noted in both ELT-3 and LM cells with significant killing (p = 0.001) at a ratio of infected:uninfected cells of only 1:99 and maximal killing at 1:4. This study demonstrates the potential efficacy of the Ad-TK/GCV gene therapy approach as a viable nonsurgical alternative treatment for uterine LM.

Image-guided transarticular atlanto-axial screw fixation

BACKGROUND

The aim of this paper was to outline the use of frameless stereotaxy for the safe insertion of C1/C2 transarticular screws in the clinical setting of patients with atlanto-axial instability.

METHODS

A retrospective review was conducted of cases involving the use of image guidance for the accurate placement of transarticular C1/C2 screws. The outcome measures considered were neural injury, vascular injury, death, and screw placement on postoperative imaging.

RESULTS

We evaluated 60 patients for image-guided C1/2 transarticular screw fixation. There was a total of 109 screws inserted. There were no intraoperative complications.

CONCLUSIONS

Frameless stereotaxy can be applied safely in a clinical setting for transarticular screw fixation. Image guidance can facilitate preoperative planning and help determine an optimal trajectory that avoids the vertebral artery.

Prostate cancer multi-feature analysis using trans-rectal ultrasound images

This note focuses on extracting and analysing prostate texture features from trans-rectal ultrasound (TRUS) images for tissue characterization. One of the principal contributions of this investigation is the use of the information of the images' frequency domain features and spatial domain features to attain a more accurate diagnosis. Each image is divided into regions of interest (ROIs) by the Gabor multi-resolution analysis, a crucial stage, in which segmentation is achieved according to the frequency response of the image pixels. The pixels with a similar response to the same filter are grouped to form one ROI. Next, from each ROI two different statistical feature sets are constructed; the first set includes four grey level dependence matrix (GLDM) features and the second set consists of five grey level difference vector (GLDV) features. These constructed feature sets are then ranked by the mutual information feature selection (MIFS) algorithm. Here, the features that provide the maximum mutual information of each feature and class (cancerous and non-cancerous) and the minimum mutual information of the selected features are chosen, yielding a reduced feature subset. The two constructed feature sets, GLDM and GLDV, as well as the reduced feature subset, are examined in terms of three different classifiers: the condensed k-nearest neighbour (CNN), the decision tree (DT) and the support vector machine (SVM). The accuracy classification results range from 87.5% to 93.75%, where the performance of the SVM and that of the DT are significantly better than the performance of the CNN.

Hysteroscopic and hysterosalpingographic study after intrauterine insertion of quinacrine pellets for non-surgical sterilization: results in 180 women

OBJECTIVES

Document the effects on the tube and uterus of one, two and three doses of 252 mg of quinacrine.

METHOD

The study included 180 fertile women seeking permanent contraception at the Shatby Family Planning Clinic in Alexandria, Egypt, in 1988. All cases received three applications of seven 36 mg quinacrine hydrochloride pellets during the proliferative phase of three consecutive menstrual cycles. The patients were randomly divided into groups A, B and C. Hysterosalpingography (HSG) was performed on the 6th day of menstruation and hysteroscopy on the 10th day of the same cycle after the first application in group A, the second, in group B and the third, in group C. The study was concluded in 1999.

RESULTS

HSG showed 52 cases of bilateral obstruction, four of bilateral patency, and four of unilateral patency in group A. All in groups B and C elicited bilateral tubal obstruction. Cornual obstruction was seen in 33%, 65% and 85% in group A, B and C, respectively. Intramural obstruction was found in 50%, 33% and 10% in the three groups. Isthmic tubal obstruction was detected in 8%, 2.5% and 5% in groups A, B and C, respectively. Four types of ostial appearances could be recognized hysteroscopically. Type 0 (patent tubes), Type I (distal tubal blockage), Type II (intramural obstruction) and Type III (cornual obstruction). In group A, Type 0 was evident in 10%, Type I in 8%, Type II in 50% and Type III in 33% of cases. The respective figures in group B were 0%, 2.5%, 33% and 65%, while in group C, they were 0%, 5%, 10% and 85%. Hysteroscopy showed no abnormal endometrial findings in group A, but 35% and 85% of cases in group B and C showed some changes.

CONCLUSIONS

Two applications of quinacrine were 100% effective. The side effects of quinacrine pellet applications were minimal and well tolerated by all the users. The possibility of reversal of the procedure is outlined.

The role of implant alignment on stability and particles on periprosthetic osteolysis?A rabbit model of implant failure

The study objective was to determine the tissue response to polyethylene and/or titanium particles and the role that these play in peri-prosthetic osteolysis in a rabbit model of implant failure. Twenty-two mature rabbits were used. Unilateral tibial arthroplasty was performed on all of them. The test animals received implants that were intentionally rotationally unstable with reference to the host tibia in order to create a model of failure. The test rabbits were divided into three groups. Group 1 consisted of seven rabbits in which only the carrier was implanted. Group 2 consisted of seven rabbits that received only polyethylene particles suspended in the carrier. Group 3 consisted of eight rabbits that received a mixture of polyethylene and titanium alloy particles suspended in the carrier. The rabbits were sacrificed at 6 months post surgery. The entire knee, together with the immediately surrounding soft tissue, was retrieved. The position of the implant in each rabbit was assessed with reference to its alignment to the tibia. The number of inflammatory, foreign-body reactive cells, the presence of neovascularization, edema, and necrosis in the periprosthetic zones were recorded and assessed in a qualitative and semiquantitative manner. Quantitative histomorphometry was used to determine the proportion of implant surface that interfaced with osseous or fibrous tissue. Also assessed was the thickness and maturity of the fibrous tissue and the endosteal remodeling activity in the peri-implant bone counting both osteoclastic and osteoblastic activity. The results showed that implanted particles and misalignment of the implants combined to produce peri-prosthetic bone resorption. Bone resorption was found to be proportional to the degree of misalignment. The animals that received combined polyethylene/titanium particles had a greater degree of foreign-body and inflammatory response with osteolysis than the other groups. The combination of bio-material particles (polyethylene and titanium alloy) produced a greater degree of bone resorption than the single biomaterial particles (polyethylene). The amount of bone resorption surrounding the implant was directly proportional to the degree of misalignment of the implant.

The peri-implant breast capsule: an immunophenotypic study of capsules taken at explantation surgery

Silicone-based breast implants continue to be the focus of many studies attempting to correlate implant failure to clinical and pathological factors. Routine pathology of peri-implant capsule is extensively described in the literature. The actual significance of the cellular events remains unconfirmed, particularly with reference to clinical outcome. This study reviews our experience with explanted capsules. The study makes specific reference to the immunohistochemistry of the cells participating in the capsule and the significance of the immunophenotypic characterization of these cells to clinical outcome. The use of a wide selection of immunomarkers for T and B lymphocytes and histiocytes provided no supporting evidence for local cell participation in the capsule, which may indicate the presence of an immunological reaction present in the capsule at the time of explantation. One was only able to confirm the presence of a low grade inflammatory process and progression to fibrosis and calcification over time. Statistical correlation was obtained only between Baker grade of capsular contracture and CD3/CD68 immunomarker positivity. CD45RO did show correlation with pain. No correlation was demonstrated with calcification. The results obtained in this study highlighted the need for further investigations into the mechanism of histiocyte and fibrocyte recruitment and activation in the capsule, a possible source of pain and contracture, which is a serious long-term clinical finding leading to the necessity for explantation.

High frequency ultrasonographic findings in plantar fasciitis and assessment of local steroid injection

OBJECTIVE

To investigate the value of ultrasonography in the diagnosis of plantar fasciitis and changes in plantar fascia following ultrasound guided local steroid injection.

METHODS

Twenty patients with a clinical diagnosis of plantar fasciitis and 20 healthy subjects were studied prospectively. Ultrasound examination was performed using an ATL Apogee 800 and linear array 11 MHz transducer. The affected heel was injected with 15 mg triamcinolone hexacetonide and 2 ml of 2% lidocaine. Ultrasound examination was performed at time of clinical evaluation, again immediately after injection, and at 1, 6, and 30 weeks later. The thickness, echogenicity, and marginal appearance of plantar fascia were measured.

RESULTS

Ultrasonographic measurement of plantar fascia showed a significant increase in symptomatic heels (range 4.8-6.5, mean 5.8 +/- 2.06 mm) compared with healthy subjects (range 1.8-3.4, mean 2.4 +/- 0.64 mm) (p < 0.001). A significant decrease in the thickness of plantar fascia was observed 1 week after local steroid injection (range 2.1-3.5, mean 2.3 +/- 0.91 mm). Complete relief of symptoms and signs was further observed at 6 and 30 weeks.

CONCLUSION

Ultrasonographic examination of plantar fascia is easy and quick to perform. Ultrasound procedure should be considered early in diagnosis and management of heel pain. Ultrasound guided local steroid injection proved safe and effective in the treatment of plantar fasciitis.

Anti-miracidial effect of recombinant glutathione S-transferase 26 and soluble egg antigen on immune responses in murine schistosomiasis mansoni

The anti-miracidial potential of recombinant Schistosoma mansoni glutathione S-transferase 26 (rSmGST26) or native crude soluble egg antigens (SEA) was assessed. The associated dynamics of granuloma formation and immune responses were evaluated. Naive C57BL/6 mice were injected intravenously with multiple doses of either SEA (SEA-group) or rSmGST26 (GST-group) 7 days before cercarial infection. The immunized groups and the respective controls were sacrificed 6, 8 and 16 weeks postinfection (p.i.). Acceleration of ova destruction and reduction of granuloma diameter were greater in the GST-group than the SEA-group, mainly at 8 weeks p.i. However, the amelioration of hepatic pathology and function was more evident in the SEA-group. Concurrently, serum-specific IgG1 levels were elevated throughout the course of infection in the immunized groups compared to the infected controls. Initial rise of all splenic cytokines and serum anti-SEA IgE levels at 6 weeks p.i. was observed, followed by a dramatic drop in the levels of the proinflammatory cytokines IL-2, IFNgamma, IL-4 and TNF-alpha and IgE at 8 weeks of infection. IL-10 level was lower at 8 weeks p.i. than at 6 weeks, but was higher in immunized groups than in infected controls. Several responses may be implicated as an outcome of the present immunization protocol, such as increased levels of blocking antibody (IgG1) and IL-10 with decreased levels of proinflammatory cytokines and IgE.

Peripheral blood vs bone marrow as a source for allogeneic hematopoietic stem cell transplantation

In this randomized prospective study, we included 30 patients with different hematological diseases (acute myeloid leukemia, acute lymphoblastic leukemia, chronic myeloid leukemia, myelodysplastic syndrome or severe aplastic anemia) to compare peripheral blood stem cells (PBSC) (15 patients; mean age 23) and bone marrow (BM) (15 patients; mean age 21.8) as a source for allogeneic transplantation regarding the tempo of hematopoietic recovery and the incidence of acute graft-versus-host disease (GVHD). In the BM group, the median nucleated cell count harvested was 1.3 x 10(10), while in the PBSC group, the aphereses contained a median of 4.4 x 10(6) CD34+/kg recipient weight. PBSC transplantation (PBSCT) was associated with faster hematopoietic reconstitution measured as absolute neutrophil count (ANC) >0.5 x 10(9)/l (log-rank P value <0.0018) and platelet count >25 x 10(9)/l (log-rank P value <0.0098). Seven patients (46.7%) in the BM group vs only one patient (6.7%) in the PBSC group developed acute GVHD (P = 0.013). Therefore, we conclude that PBSCT is associated with faster hematopoietic recovery and the incidence of acute GVHD does not exceed that seen with BMT.

Identification and prevalence of rheumatoid nodules in the finger tendons using high frequency ultrasonography

OBJECTIVE

Rheumatoid nodules are classical diagnostic feature of rheumatoid arthritis (RA). The prevalence of rheumatoid nodules in the finger tendons is not known. We determined the prevalence of rheumatoid nodules of finger tendons in patients with RA, using high frequency linear transducers with high resolution ultrasonography.

METHODS

The study comprised 54 consecutive patients with RA and 20 controls. Dynamic ultrasound examination of various tendons was performed using real-time equipment, the Apogee 800 ATL, with an 11 MHz linear array transducer.

RESULTS

RA nodules were identified in 9 patients (16.66%); their sizes ranged from 0.21 to 0.95 cm (mean 0.35+/-0.12 cm), in 4 cases (7.4%) the nodules were intratendinous. The flexor tendons were affected in the 9 patients. The finger tendon ultrasonography identified RA nodules that had escaped routine clinical detection.

CONCLUSION

The ultrasonography technique was valuable in the confirmation of rheumatoid nodule involvement of the finger tendons. The prevalence of rheumatoid nodule in finger tendons was 16.66%. We believe that ultrasonography should be the screening procedure of choice for diagnosis of RA nodules of the fingers.

Terminals of paraventricular spinal neurones are closely associated with adrenal medullary sympathetic preganglionic neurones: immunocytochemical evidence for vasopressin as a possible neurotransmitter in this pathway

A recent study using transsynaptically transported pseudorabies virus, injected into the adrenal gland, showed labelled neurones in the paraventricular nucleus (PVN) of the hypothalamus, indicating that these neurones send projections to sympathoadrenal preganglionic neurones (SPNs). However, this technique cannot conclusively demonstrate that the pathway is monosynaptic. In order to investigate the possibility of a direct projection from the PVN to SPNs, the present study used the anterograde tracer biotin dextran amine to label paraventricular spinal projections and the retrograde tracer cholera toxin B conjugated to horseradish peroxidase to label SPNs. In addition, because electrophysiological evidence suggests vasopressin to be a neurotransmitter candidate in this pathway, immunocytochemical identification of the peptide and retrograde labelling of SPNs to the adrenal medulla were used to investigate this. The results of these studies show spinally projecting paraventricular axons with terminal varicosities closely associated with SPNs. Therefore some of these associations may represent boutons forming synaptic contact on SPNs. Similarly, vasopressin fibres were found close to the dendrites and soma of SPNs. It is suggested that spinal axons originating from paraventricular neurones can provide a direct influence on adrenal medullary function, that vasopressin is a possible neurotransmitter involved in some of these connections and this is one means by which the paraventricular nucleus can generate a defence to stressful stimuli.

Modular neural networks: a survey

Modular Neural Networks (MNNs) is a rapidly growing field in artificial Neural Networks (NNs) research. This paper surveys the different motivations for creating MNNs: biological, psychological, hardware, and computational. Then, the general stages of MNN design are outlined and surveyed as well, viz., task decomposition techniques, learning schemes and multi-module decision-making strategies. Advantages and disadvantages of the surveyed methods are pointed out, and an assessment with respect to practical potential is provided. Finally, some general recommendations for future designs are presented.