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Biomedical subjects

M Kamel

Publications and source records attributed to M Kamel.

At least 19 recordsLinked to original sources
PubMed2006

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.

Adenoviridae↗
PubMed2006

Granular cell tumour of the neurohypophysis: a rare sellar tumour with specific radiological and operative features.

Symptomatic granular cell tumours of the neurohypophysis are rare sellar lesions. Preoperative prediction of the diagnosis on the basis of radiological appearance is useful as these tumours carry specific surgical difficulties. This is possible when the tumour arises from the pituitary stalk, rostral to a normal pituitary gland. This has not been emphasized previously.

Granular Cell Tumor↗
PubMed2005

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.

Algorithms↗
PubMed2004

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.

Alloys↗
PubMed2003

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.

Adult↗
PubMed2001

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.

Adult↗
PubMed2000

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.

Adult↗
PubMed1999

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.

Adrenal Medulla↗
PubMed1999

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.

Adult↗
PubMed1999

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.

Alanine Transaminase↗
PubMed1999

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.

Biology↗
PubMed1999

Cartilaginous metaplasia in the capsule of a Dacron-backed silicone gel breast prosthesis.

Capsular metaplastic changes described as "synovial metaplasia" have been reported in association with silicone gel breast prostheses. Initially this finding was thought to be more common with textured implants. Recent studies have shown no relation between implant shell type (textured vs. smooth). The incidence of this metaplasia has been shown to decrease with the age of the implant, suggesting that it is a transitional finding in capsular maturation. The metaplastic cells in the synovial metaplasia may have secretory characteristics, but the exact etiology and function of the metaplasia are not yet fully understood. Experimentally, a similar connective tissue reaction has been induced by repeated injections of air to produce the so-called "air pouch." The current study describes cartilaginous metaplasia in the capsule surrounding a silicone-filled, Cronin-type, Dacron-backed breast prosthesis. At 26 years after bilateral breast augmentation, this patient presented with breast pain and firmness. During surgical removal the implants were intact but the capsules were densely hyalinized, irregularly calcified, and on one side there was cartilaginous metaplasia within the connective tissue of the capsule. This had occurred independently of calcification. This was believed to be an unusual tissue response. Review of the English literature failed to identify a comparable case.

Breast↗
PubMed1999

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.

Arthritis, Rheumatoid↗
PubMed1998

Capsular calcification associated with silicone breast implants: incidence, determinants, and characterization.

Capsular calcification was present clinically in 64 of 404 silicone gel breast implant capsules (15.8%) analyzed from 1981 to 1996. It presented as white-gray plaques on the inner surface of capsules in 62 of 64 capsules, and as massive heterotopic ossification in 2 capsules. Chi-squared analysis confirmed that calcification was related to the generation of the implant (i.e., year of manufacture; p < 0.001). All 28 first-generation implants (1963-1972, with Dacron patches) were clinically intact and all demonstrated extensive calcification. Their mean duration in situ was 17.6 years (range, 14-28 years). Thirty-four of the 348 second-generation implants (9.8%; 1973-1987) were associated with capsular calcification. Their mean duration in situ was 16.0 years (range, 13-22 years). Because all first-generation implants demonstrated calcification, they were compared with the second-generation implants that had been in place for the same duration (>14 years). Only 42% of these 81 second-generation implants demonstrated calcification, compared with 100% of the first-generation implants (p < 0.001). Thus, thicker first-generation implants with Dacron patches are more likely to calcify and the effect is not entirely due to their longevity. None of the 28 third-generation implants (1987-1991) demonstrated calcification. Their mean duration in situ was 4.2 years (range, 2-7 years). For second-generation implants, calcification was related to duration in situ (p < 0.001). None of the 294 implants in place for less than 11 years were associated with significant clinical calcification. The percentages of capsules with calcification were 13 to 14 years, 33%; 15 to 16 years, 45%; and 17 to 22 years, 57%. Calcification with second-generation implants was not associated with patches on the envelopes. Of the 34 second-generation implants with calcification, only two had patches (composed of silicone, not Dacron). Among second-generation implants, calcification was related to implant integrity. Of implants in place for more than 12 years, 52.5% of those implants that were ruptured showed calcification, but only 10.0% of intact implants demonstrated calcification (p < 0.001). Seventeen of the 64 calcified capsules were examined histologically. In all of these specimens, calcification existed in two forms: globular aggregates on the surface of the capsule (adjacent to the implant) and actual bone formation within the fibrous tissue of the capsule. All calcified capsules demonstrated both globular aggregates and true bone formation regardless of the implant generation, duration in situ, or integrity. Ultrastructural analysis was performed on four capsules from 2 women who had received first-generation Dow Corning gel implants 24 and 28 years previously, and on 2 capsules from one woman who had received Heyer-Schulte gel implants 21 years previously. These capsules were analyzed according to distribution, density, mineral nature, crystal phases, and elements within crystals by electron microscopy, energy-dispersive X-ray spectrometry, and electron diffraction. These analyses confirmed two types of calcification, each with hydroxyapatite crystals. In areas of heterotopic bone, crystals 40 x 10 nm were deposited in an orderly fashion on collagen fibers. In contrast, in areas of globular aggregates, spherulitic aggregates of much larger crystals were present, without any relationship to the collagen. Titanium was demonstrated in capsules of first-generation implants at areas of attachment of the Dacron patches. The calcification associated with saline implants revealed only one form of crystal: agglomerates, which were adherent to the elastomeric shell of the implants. A hypothesis is presented to explain the differences in calcification deposition properties between silicone gel-filled and saline-filled breast implants.

Adult↗
PubMed1998

Vitamin D administration to tuberculous children and its value.

Our study was done to assess the value of administration of vitamin D to tuberculous children. The study included twenty four newly diagnosed tuberculous children; eleven males and thirteen females. Their age ranged from one and half to thirteen years. Thirteen patients were extra thoracic type of T.B., while only seven were intrathoracic and the rest were mixed. They were randomly divided into two Groups according to the treatment administered: Group A patients were given Rifampicin, Isoniazid and Streptomycin. Group B received in addition vitamin D. After eight weeks therapy, the patients of each group were evaluated regarding clinical, laboratory, and radiological improvement. Vitamin D level is raised after treatment in both Groups A and B, but this rise is not significant. It also showed insignificant difference between the two groups. Vitamin D level showed very high significant decrease in tuberculous children than matched healthy controls (non tuberculous children). Calcium was significantly elevated after treatment in Group A whereas no significant change was detected in Group B. Phosphorous was highly significantly elevated after treatment in Group A, whereas in Group B it is just significantly elevated. Alkaline phosphatase level in both groups A and B were slightly decreased after treatment. However, this decrease was not significant. Clinical improvement was more evident in Group B patients (those taking vitamin D) as compared to Group A patients. The same was noted with X-ray and Sonographic findings. We concluded that vitamin D therapy may be of great value in addition to antituberculous drugs in the treatment of tuberculous children, and its use is highly recommended.

Adolescent↗
PubMed1997

Effectiveness of clinical guidelines for the presumptive treatment of streptococcal pharyngitis in Egyptian children.

BACKGROUND: Primary prevention of acute rheumatic fever requires antibiotic treatment of acute streptococcal pharyngitis. In developing countries, clinicians must rely on clinical guidelines for presumptive treatment of streptococcal pharyngitis since bacterial culture and rapid diagnostic tests are not feasible. We evaluated the WHO Acute Respiratory Infection guideline in a large urban paediatric clinic in Egypt. METHODS: Children between 2 and 13 years of age who had a sore throat and pharyngeal erythema were enrolled in the study. Clinical, historical, and demographic information was recorded and a throat culture for group A beta-haemolytic streptococci was done. Sensitivity (% of true-positive throat cultures) and specificity (% of true-negative throat cultures) were calculated for each clinical feature. The effect of various guidelines on correct presumptive treatment for throat-culture status was calculated. FINDINGS: Of 451 children with pharyngitis, 107 (24%) had group A beta-haemolytic streptococci on throat culture. A purulent exudate was seen in 22% (99/450) of these children and this sign was 31% sensitive and 81% specific for a positive culture. The WHO Acute Respiratory Infections (ARI) guidelines, which suggest treatment for pharyngeal exudate plus enlarged and tender cervical node, were 12% sensitive and 94% specific; 13/107 children with a positive throat culture would correctly receive antibiotics and 323/344 with a negative throat culture would, correctly, not receive antibiotics. Based on our data we propose a modified guideline whereby exudate or large cervical nodes would indicate antibiotic treatment, and this guideline would be 84% sensitive and 40% specific; 90/107 children with a positive throat culture would correctly receive antibiotics and 138/344 with a negative throat culture would, correctly, not receive antibiotics. INTERPRETATION: The WHO ARI clinical guideline has a high specificity but low sensitivity that limits the unnecessary use of antibiotics, but does not treat 88% of children with a positive streptococcal throat culture who are at risk of acute rheumatic fever. A modified guideline may be more useful in this population. Prospective studies of treatment guidelines from many regions are needed to assess their use since the frequency of pharyngitis varies.

Adolescent↗