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Biomedical subjects

A M Talaat

Publications and source records attributed to A M Talaat.

17 recordsLinked to original sources
PubMed2002

Endoscopically assisted minimally invasive microvascular decompression of hemifacial spasm.

OBJECTIVE: The aim of this study was to assess the use of endoscopy in minimally invasive surgery of the cerebellopontine angle in cases of hemifacial spasm. MATERIALS AND METHODS: Eighty patients with hemifacial spasm underwent endoscopically assisted microvascular decompression between October 1992 and October 1998, at the Ear, Nose, and Throat Department of Nord Hospital in Marseille, France. The microvascular decompression was performed via a minimally invasive retrosigmoid approach. The cerebellopontine angle was then explored by a 30-degree endoscope to visualize the root exit zone of the facial nerve and the precise location of the site of the conflict. Microvascular decompression was performed under the microscope. If the site was an artery, a Teflon sponge was inserted; if the site was a vein, it was coagulated and then dissected away from the facial nerve. RESULTS: In 80 patients seen regularly for at least 1 year of follow-up, and including patients operated on once or twice, the procedure was successful in 92.5% of patients, brought about improvement in 3.75% (96.25% success plus improvement), and failed in 3.75%. In relation to the type of conflict, success or improvement was experienced by 90.7% of patients with simple conflicts, 86.2% of patients with multiple conflicts, and 87.5% of patients with nutcracker conflicts. No major postoperative complication or mortality occurred in this series. No facial paresis or paralysis occurred immediately postoperatively. Three patients (3.25%) experienced delayed facial palsy. Postoperative cerebrospinal fluid leak occurred in 2 patients (2.5%) and was treated surgically. CONCLUSION: The principle of minimally invasive surgery in the cerebellopontine angle is gaining universal acceptance. The use of endoscopy in microvascular decompression for hemifacial spasm has helped tremendously in improving the results. In this study, the use of the endoscope enabled the authors to identify the site of the conflict in all cases, and to confirm the position of the Teflon sponge before closure.

Adult↗
PubMed2002

Endoscopy as a tool in minimally invasive trigeminal neuralgia surgery.

OBJECTIVE: The aim of this study was assessment of the use of endoscopy in minimally invasive surgery of the cerebellopontine angle in cases of trigeminal neuralgia. METHODS: This study comprises 42 cases of trigeminal neuralgia that underwent operation with endoscopic-assisted microvascular decompression between October 1992 and October 1998. This study was performed in the Ear, Nose, and Throat Department, Nord Hospital, in Marseille, France. The decompression was performed by means of a minimally invasive retrosigmoid approach without a cerebellar retractor. The cerebellopontine angle was then explored by a 30-degree endoscope that gives a panoramic view of this space, with clear visualization of the trigeminal nerve from the pons to Meckel's cave, allowing for the identification of the precise location of the site of the conflict. Microvascular decompression was performed under the microscope by separating the offending vessel from the trigeminal nerve; separation was maintained by the insertion of a piece of Teflon. RESULTS: The site of conflict was detected at the root entry zone of the nerve in 35 patients (83.3%) and at Meckel's cave in 7 patients (16.7%). In 32 cases (76.2%), the type of contact between the vessel and the nerve was of the simple type (1 vessel coming in contact with the nerve in a single point); in 6 cases (14.3%), it was a multiple type (2 vessels touching the nerve in the same point); and in 4 cases (9.5%), it was a nutcracker type (2 vessels compressing the nerve between them). After at least 1-year follow-up and a single operation (cases that required a second operation for revision were considered failures), a successful result was obtained in 31 cases (73.8%), and an improvement was obtained in 4 cases (9.5%). The operation was a failure or early recurrence occurred in 7 cases (16.7%). Postoperative complications were rare. A cerebrospinal fluid leak occurred in only 1 case (2.4%) and was subsequently treated with lumbar puncture and a compressive bandage. CONCLUSION: The minimally invasive retrosigmoid endoscopic-assisted microvascular decompression is an acceptable treatment of primary trigeminal neuralgia. Endoscopy provides a unique way to explore the cerebellopontine angle and to identify the exact location of the neurovascular conflict.

Adult↗
PubMed2001

A combination vaccine confers full protection against co-infections with influenza, herpes simplex and respiratory syncytial viruses.

Combined/composite vaccines should be useful in reducing the number of vaccinations and provide more flexibility in confronting biological warfare scenarios. We tested the effectiveness of a composite genetic vaccine designed from previously known protective antigens directed against influenza A virus (INF-A), herpes simplex virus type-1 (HSV-1) and respiratory syncytial virus (RSV) in a mouse-based challenge. Immunizing mice with a pool of four plasmids; INF-A haemagglutinin (HA), INF-A nucleoprotein (NP), HSV-1 glycoprotein D (gD) and RSV glycoprotein F, against the three pathogens provided full protection when mice were challenged with each pathogen. Remarkably, mice challenged with all three pathogens at once were also fully protected, even when a bacterial pathogen, Mycoplasma pulmonis, was included in the challenge. If these results are extendable to other combinations of vaccines in other hosts, it would support the development of gene vaccines as multi-component, combination vaccines.

Animals↗
PubMed2000

Genome-directed primers for selective labeling of bacterial transcripts for DNA microarray analysis.

DNA microarrays have the ability to analyze the expression of thousands of the same set of genes under at least two different experimental conditions. However, DNA microarrays require substantial amounts of RNA to generate the probes, especially when bacterial RNA is used for hybridization (50 microg of bacterial total RNA contains approximately 2 microg of mRNA). We have developed a computer-based algorithm for prediction of the minimal number of primers to specifically anneal to all genes in a given genome. The algorithm predicts, for example, that 37 oligonucleotides should prime all genes in the Mycobacterium tuberculosis genome. We tested the usefulness of the genome-directed primers (GDPs) in comparison to random primers for gene expression profiling using DNA microarrays. Both types of primers were used to generate fluorescent-labeled probes and to hybridize to an array of 960 mycobacterial genes. Compared to random-primer probes, the GDP probes were more sensitive and more specific, especially when mammalian RNA samples were spiked with mycobacterial RNA. The GDPs were used for gene expression profiling of mycobacterial cultures grown to early log or stationary growth phases. This approach could be useful for accurate genome-wide expression analysis, especially for in vivo gene expression profiling, as well as directed amplification of sequenced genomes.

Algorithms↗
PubMed2000

Transformation and transposition of the genome of Mycobacterium marinum.

OBJECTIVE: To develop and evaluate protocols for genetic manipulations (transformation and transposition) of the fish pathogen, Mycobacterium marinum. SAMPLE POPULATION: Isolates of M. marinum obtained from fish and humans. PROCEDURE: Electrocompetent cells were prepared from isolates of M. marinum grown to various growth phases at several temperatures and with or without the addition of ethionamide or cycloheximide. Mycobacterial cells were transformed by electroporation with a replicative Escherichia coli-mycobacteria shuttle vector (pYUB18) as well as suicide vectors (pYUB285 and pUS252) that carried transposable elements (IS1096 and IS6110, respectively). Mutants from both isolates of M. marinum were recovered on 7H10 agar plates supplemented with kanamycin. Transformation and transposition efficiencies for various protocols were compared. Southern hybridization analysis was performed on mycobacterial mutants to confirm transposition events. RESULTS: Competent cells prepared at room temperature (23-25 C) from organisms in late-exponential growth phase yielded higher transposition efficiency, compared with cells prepared at 4 C or from organisms in early- or mid-exponential growth phase. Naturally developing kanamycin-resistant colonies of M. marinum were not detected. Only the IS1096-derived transposition was able to efficiently mutate M. marinum. Southern hybridization of M. marinum mutants revealed random integration of IS 1096 into the M. marinum genome. CONCLUSIONS: Transposition and transformation efficiencies were comparable, suggesting that the limiting factor in transposition is the transformation step. Most of the experiments resulted in transposition of IS1096; however, better approaches are needed to improve transposition efficiency.

Animals↗
PubMed1999

Pathogenicity of Mycobacterium fortuitum and Mycobacterium smegmatis to goldfish, Carassius auratus.

Despite the ubiquitous presence of atypical mycobacteria in the environment and the potential risk of infection in humans and animals, the pathogenesis of diseases caused by infection with atypical mycobacteria has been poorly characterized. In this study, goldfish, Carassius auratus were infected either with the rapidly growing fish pathogen, Mycobacterium fortuitum or with another rapidly growing mycobacteria, Mycobacterium smegmatis. Bacterial persistence and pathological host response to mycobacterial infection in the goldfish are described. Mycobacteria were recovered from a high percentage of inoculated fish that developed a characteristic chronic granulomatous response similar to that associated with natural mycobacterial infection. Both M. fortuitum and M. smegmatis were pathogenic to fish. Fish infected with M. smegmatis ATCC 19420 showed the highest level of giant cell recruitment compared to fish inoculated with M. smegmatis mc(2)155 and M. fortuitum. Of the three strains of mycobacteria examined, M. smegmatis ATCC 19420 was the most virulent strain to goldfish followed by M. fortuitum and M. smegmatis mc(2)155, respectively.

Animals↗
PubMed1998

Goldfish, Carassius auratus, a novel animal model for the study of Mycobacterium marinum pathogenesis.

We have developed an animal model for studying mycobacterial pathogenesis using Mycobacterium marinum and the goldfish, Carassius auratus. Goldfish are injected intraperitoneally with doses between 10(2) and 10(9) CFU of M. marinum organisms. Depending on the dose of M. marinum organisms administered, an acute or chronic disease is produced. The acute disease is characterized by systemic mycobacterial infection, severe peritonitis, tissue necrosis, and a short median survival time. The chronic disease is characterized by granuloma formation in all organs and survival of animals to the end point of the experiment (56 days). Colony counts in organ homogenates showed recovery of mycobacteria from a high percentage of inoculated animals. We believe this well-characterized animal model will be useful for studying mycobacterial pathogenesis.

Acute Disease↗
PubMed1997

Identification of mycobacteria infecting fish to the species level using polymerase chain reaction and restriction enzyme analysis.

An assay is described utilizing PCR technology for a rapid diagnostic test to identify fish infection with Mycobacterium marinum, M. fortuitum and M. chelonae. A 924 bp DNA fragment from a highly conserved area of the mycobacterial 16S rRNA gene was amplified using mycobacteria genus-specific primers and digested with restriction enzymes (BanI and ApaI). This examination yielded unique restriction patterns for each mycobacterial specie enabling identification of mycobacteria infecting fish to the species level. The protocol can be applied to purified DNA, a simple colony preparation or infected fish tissue. This protocol can be completed in 1-2 days.

Animals↗
PubMed1989

Nasopharyngeal bacterial flora before and after adenoidectomy.

Fifty patients (23 males and 27 females), with chronically hypertrophied and infected adenoids were subjected to adenoidectomy. Pre- and post-operative nasopharyngeal swabs were taken to study bacterial colonization of the nasopharynx both quantitatively and qualitatively. Twenty healthy controls were included in this study. The swabs were cultured on MacConkey's and Columbia blood agar plates. The rate of isolation of potentially pathogenic microorganisms decreased markedly following operation, while normal inhabitant organisms showed notable increase in their numbers post-operatively to reach a near normal level. It is concluded from this work that adenoidectomy produces a physiological effect on the nasopharyngeal microflora by conversion of an abnormal flora to a nearly normal one.

Adenoidectomy↗
PubMed1983

Cardiopulmonary changes secondary to chronic adenotonsillitis.

Thirty children with lower respiratory tract infection of varying degrees secondary to chronic tonsillitis and/or enlarged adenoids were studied clinically and roentgenographically. Symptoms and signs of alveolar hypoventilation and signs of cor pulmonale were present in two of them. These symptoms and signs improved markedly after adenoidectomy and tonsillectomy. The relationship of the lung changes to the incidence of cor pulmonale is discussed. The development of recurrent attacks of severe lower respiratory tract infection secondary to diseased tonsils and adenoids is believed to play an important role in the pathogenesis of cor pulmonale in children with upper respiratory tract obstruction due to chronically enlarged tonsils and adenoids.

Adenoids↗
PubMed1983

Ceruminous glands in otosclerosis. A histopathological and histochemical study.

The ceruminous glands of the external auditory canal skin of 20 patients suffering from otosclerosis were examined histologically and histochemically. The histological changes included flattening of the lining cells and widening of the lumina of the glands. Histochemical alterations were in the form of diminished succinic dehydrogenase, alpha esterase and alkaline phosphatase enzyme activities. The histological and histochemical changes indicated that atrophy of the ceruminous glands with diminished wax production occurred in some otosclerotic patients. This atrophy may be secondary to the involvement of the ground substance, vessels and nerves of the external auditory canal by the same etiologic factor responsible for the pathogenesis of the otosclerotic process.

Cerumen↗
PubMed1980

Human respiratory nasal mucosa in progressive systemic sclerosis (scleroderma). An electron microscopic study.

The fine structure of the respiratory nasal mucosa in cases of systemic scleroderma was studied in 5 patients. The cilia were absent in all the sections examined, and the epithelium showed characteristic morphological details. Absence of the mucous elements in the sero-mucinous glands was noticed with evidence of increased activity of the serous units. The capillaries and small arterioles showed severe changes. Electron-dense deposits were seen within the various constituents of the nasal mucosa. It was assumed that the characteristics of the disease are dependent on individual reactivity of a genetically determined immune system stimulated by an undetermined factor.

Adult↗
PubMedDate not supplied

Physical therapy in the management of myofacial pain dysfunction syndrome.

A study of the effectiveness of physical therapy for patients with myofacial pain dysfunction syndrome was performed. Clinical evaluation of 120 patients revealed marked male preponderance, distribution according to age showed a great prevalence of the third decade, and most common chief complaints were pain and muscle tenderness. Patients were classified randomly into three equal groups treated by muscle relaxant drugs, shortwave diathermy, and ultrasonic therapy, respectively. Regular follow-up was carried out for 6 to 12 months to assess patients' responses to different forms of treatment. Evaluation revealed marked relief of symptoms by the use of physical therapy, and the best results were obtained by the use of ultrasonic therapy.

Adolescent↗
PubMedDate not supplied

Histologic and histochemical study of effects of anabolic steroids on the female larynx.

The larynges of 30 unmated, mature female albino mice were examined histologically and histochemically after injecting them with 19-nandrolone phenylpropionate. Permanent irreversible changes, in the form of parakeratosis and squamous metaplasia of the epithelium, and hypertrophy of the muscle fibers, were observed together with persistence of increased alkaline phosphatase enzyme intensity in the endothelium of capillaries and increased activity of nonspecific esterase in the muscles. Similar changes may be responsible for the alteration in the human female's voice after prolonged treatment with anabolic steroids.

Anabolic Agents↗