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Biomedical subjects

N Salama

Publications and source records attributed to N Salama.

At least 19 recordsLinked to original sources
PubMed2004

Satisfaction with the malleable penile prosthesis among couples from the Middle East--is it different from that reported elsewhere?

No studies from the Middle East have investigated the psychosexual aspects of penile prosthesis. Therefore, several questions were used herein to address satisfaction with the use of malleable penile prosthesis among couples from this geographic area, as an option to treat erectile dysfunction (ED). A total of 50 patients who underwent the insertion of AMS 650 and Acu-form penile prostheses and their partners were evaluated with a retrospective clinical record review, as well as patient and partner questionnaires. In all, 70% of the patients and 57% of the partners were satisfied with the prosthesis. There was an increase in frequency of intercourse, sexual desire, and ability to achieve orgasm. Dislike for the device was the most common cause for nonsatisfaction of patients with the device, while sense of unnaturalness was that for partners. Results from this evaluation highlight the obvious need for proper preoperative counseling for both the patient and his partner to minimize unrealistic expectations. They also emphasize the importance of careful screening of both psychosocial and psychosexual aspects of the couple based on cultural ethnic background, since these are important predictors of the therapeutic outcome of prosthesis insertion. Efforts to extend information about ED to the public may be useful to reduce patients' exaggerated embarrassment about this problem and make their partners actively involved in the treatment.

Adolescent↗
PubMed2004

Nocturnal electrobioimpedance volumetric assessment in diabetic men with erectile dysfunction before and after tadalafil intake.

Nocturnal electrobioimpedance volumetric assessment (NEVA) is a procedure that can measure penile volume changes together with the number and duration of nocturnal erectile events. This study was conducted to evaluate the different NEVA patterns in diabetic patients with erectile dysfunction (ED), and demonstrate the extent to which tadalafil may affect the characteristics of nocturnal penile erections in these patients. Therefore, 38 patients with noninsulin-dependent diabetes and ED participated in this study. They were assessed with history intake including evaluation by the abridged five-item version of International Index of Erectile Function, clinical and psychiatric assessment and NEVA for three consecutive nights where placebo was given on the second night and tadalafil on the third night. In all, 14 potent males were taken as a control group. Data were analyzed using t-test. Results showed normal patterns in only six (16%) patients (central organic group), while abnormal patterns were observed in the remaining 32 (84%) patients (peripheral organic group). These abnormal patterns showed significant decrease in both the number (P=0.0001) and duration (P=0.03) of erectile events compared to those of controls. The percentage of penile blood volume change over baseline also decreased significantly (P=0.0002) relative to controls. Veno-occlusive dysfunction was the main pathology (23 patients, 72%) as suggested by NEVA. Tadalafil did not significantly change basal nocturnal penile tumescence results in either the central organic or control groups, but it did so significantly in the peripheral organic group (P=0.02 for duration change and P=0.01 for % blood volume change). In conclusion, NEVA may suggest some evidence about the pathophysiology of an underlying vasculogenic cause, thus directing towards the next specific step needed for a precise diagnosis. Tadalafil improves nocturnal erections in diabetic patients with peripheral but not central organic impotence.

Arterial Occlusive Diseases↗
PubMed2001

Helicobacter pylori genetic diversity within the gastric niche of a single human host.

Isolates of the gastric pathogen Helicobacter pylori harvested from different individuals are highly polymorphic. Strain variation also has been observed within a single host. To more fully ascertain the extent of H. pylori genetic diversity within the ecological niche of its natural host, we harvested additional isolates of the sequenced H. pylori strain J99 from its human source patient after a 6-year interval. Randomly amplified polymorphic DNA PCR and DNA sequencing of four unlinked loci indicated that these isolates were closely related to the original strain. In contrast, microarray analysis revealed differences in genetic content among all of the isolates that were not detected by randomly amplified polymorphic DNA PCR or sequence analysis. Several ORFs from loci scattered throughout the chromosome in the archival strain did not hybridize with DNA from the recent strains, including multiple ORFs within the J99 plasticity zone. In addition, DNA from the recent isolates hybridized with probes for ORFs specific for the other fully sequenced H. pylori strain 26695, including a putative traG homolog. Among the additional J99 isolates, patterns of genetic diversity were distinct both when compared with each other and to the original prototype isolate. These results indicate that within an apparently homogeneous population, as determined by macroscale comparison and nucleotide sequence analysis, remarkable genetic differences exist among single-colony isolates of H. pylori. Direct evidence that H. pylori has the capacity to lose and possibly acquire exogenous DNA is consistent with a model of continuous microevolution within its cognate host.

Chromosomes, Bacterial↗
PubMed2001

Comparison of genetic divergence and fitness between two subclones of Helicobacter pylori.

Helicobacter pylori has a very plastic genome, reflecting its high rate of recombination and point mutation. This plasticity promotes divergence of the population by the development of subclones and presumably enhances adaptation to host niches. We have investigated the genotypic and phenotypic characteristics of two such subclones isolated from one patient as well as the genetic evolution of these isolates during experimental infection. Whole-genome genotyping of the isolates using DNA microarrays revealed that they were more similar to each other than to a panel of other genotyped strains recovered from different hosts. Nonetheless, they still showed significant differences. For example, one isolate (67:21) contained the entire Cag pathogenicity island (PAI), whereas the other (67:20) had excised the PAI. Phenotypic studies disclosed that both isolates expressed adhesins that recognized human histo-blood group Lewis(b) glycan receptors produced by gastric pit and surface mucus cells. In addition, both isolates were able to colonize, to equivalent density and with similar efficiency, germ-free transgenic mice genetically engineered to synthesize Lewis(b) glycans in their pit cells (12 to 14 mice/isolate). Remarkably, the Cag PAI-negative isolate was unable to colonize conventionally raised Lewis(b) transgenic mice harboring a normal gastric microflora, whereas the Cag PAI-positive isolate colonized 74% of the animals (39 to 40 mice/isolate). The genomic evolution of both isolates during the infection of conventionally raised and germ-free mice was monitored over the course of 3 months. The Cag PAI-positive isolate was also surveyed after a 10 month colonization of conventionally raised transgenic animals (n = 9 mice). Microarray analysis of the Cag PAI and sequence analysis of the cagA, recA, and 16S rRNA genes disclosed no changes in recovered isolates. Together, these results reveal that the H. pylori population infecting one individual can undergo significant divergence, creating stable subclones with substantial genotypic and phenotypic differences.

Adhesins, Bacterial↗
PubMed2001

Helicobacter pylori strain-specific differences in genetic content, identified by microarray, influence host inflammatory responses.

Helicobacter pylori enhances the risk for ulcer disease and gastric cancer, yet only a minority of H. pylori-colonized individuals develop disease. We examined the ability of two H. pylori isolates to induce differential host responses in vivo or in vitro, and then used an H. pylori whole genome microarray to identify bacterial determinants related to pathogenesis. Gastric ulcer strain B128 induced more severe gastritis, proliferation, and apoptosis in gerbil mucosa than did duodenal ulcer strain G1.1, and gastric ulceration and atrophy occurred only in B128+ gerbils. In vitro, gerbil-passaged B128 derivatives significantly increased IL-8 secretion and apoptosis compared with G1.1 strains. DNA hybridization to the microarray identified several strain-specific differences in gene composition including a large deletion of the cag pathogenicity island in strain G1.1. Partial and complete disruption of the cag island in strain B128 attenuated induction of IL-8 in vitro and significantly decreased gastric inflammation in vivo. These results indicate that the ability of H. pylori to regulate epithelial cell responses related to inflammation depends on the presence of an intact cag pathogenicity island. Use of an H pylori whole genome microarray is an effective method to identify differences in gene content between H. pylori strains that induce distinct pathological outcomes in a rodent model of H. pylori infection.

Animals↗
PubMed2001

Improving standards in the treatment of acute otitis externa by the use of a treatment protocol and open access to aural toilet.

A prospective audit of the procedure and outcome in the management of acute otitis externa was undertaken in our unit. The first cycle demonstrated a heterogeneous approach and clinical isolation of junior staff. A questionnaire survey of local general practitioners highlighted clinical confusion over the use of topical medication and a need for improved access to facilities for aural toilet. General practitioner liaison and education was an essential component in formulating a change in practice. In particular, open access for aural toilet was introduced and utilization encouraged. Following changes in practice, the second cycle of the audit showed that treatment protocols were effective and adhered to by junior staff.

Acute Disease↗
PubMed2001

The effectiveness of guidelines in reducing inappropriate CT scans of the paranasal sinuses.

An effective system for scoring pathological changes on CT scans of the paranasal sinuses has been developed by Lund & Mackay. We have performed an audit using 100 outpatients with nasal symptoms and found that adherence to guidelines prior to ordering CT scans of the paranasal sinuses correlates with an increased average Lund & Mackay score. Using these guidelines has also reduced the number of inappropriate CT scan requests.

Humans↗
PubMed2000

A whole-genome microarray reveals genetic diversity among Helicobacter pylori strains.

Helicobacter pylori colonizes the stomach of half of the world's population, causing a wide spectrum of disease ranging from asymptomatic gastritis to ulcers to gastric cancer. Although the basis for these diverse clinical outcomes is not understood, more severe disease is associated with strains harboring a pathogenicity island. To characterize the genetic diversity of more and less virulent strains, we examined the genomic content of 15 H. pylori clinical isolates by using a whole genome H. pylori DNA microarray. We found that a full 22% of H. pylori genes are dispensable in one or more strains, thus defining a minimal functional core of 1281 H. pylori genes. While the core genes encode most metabolic and cellular processes, the strain-specific genes include genes unique to H. pylori, restriction modification genes, transposases, and genes encoding cell surface proteins, which may aid the bacteria under specific circumstances during their long-term infection of genetically diverse hosts. We observed distinct patterns of the strain-specific gene distribution along the chromosome, which may result from different mechanisms of gene acquisition and loss. Among the strain-specific genes, we have found a class of candidate virulence genes identified by their coinheritance with the pathogenicity island.

DNA, Bacterial↗
PubMed1999

Ultra-structural changes in collagen of penile tunica albuginea in aged and diabetic rats.

Tunica albuginea (TA) of the penis, which has an important role in mechanism of erection, is composed mainly of collagen bundles. Both aging and diabetes mellitus (DM) were reported to be associated with many alterations in collagen content and architecture in several body tissues. So, the aim of this work was to evaluate the effects of both conditions on the collagen bundles of penile TA in rats. Our diabetic models were three groups of Zucker Diabetic Fatty (ZDF) rats with non-insulin-dependent DM (NIDDM) aged 15, 40 and 75 weeks. Their age-matched controls were Zucker Fatty (ZF) rats. TA were excised from the side of mid-penile shaft and were examined by scanning electron microscopy using chemical digestion to extract collagen components. With aging, only the (70 w) ZF rats showed a significant increase in both thickness (P < 0.005) and loss of undulation of its bundles (P < 0.005) compared with the younger animals. In ZDF animals, a significant gradual increase in bundle thickness (P < 0.005) and loss of its undulation (P < 0.005) were found as the disease progressed to 40 w duration. Comparing these two parameters between both study groups showed that DM animals had significantly higher bundle thickness (P < 0.005) with loss of its undulation (P < 0.005) than controls starting from 40 w old. In conclusion, with progress of both aging and NIDDM, an increase in both thickness and loss of undulation of collagen bundles of penile TA was appreciated. The association of DM with aging could represent a cofactor effect that ultimately led to a greater impact on architecture of the bundles. The resulting changes may explain the compromised rigidity of the penis during erection under both conditions.

Aging↗
PubMed1994

COPII: a membrane coat formed by Sec proteins that drive vesicle budding from the endoplasmic reticulum.

In vitro synthesis of endoplasmic reticulum-derived transport vesicles has been reconstituted with washed membranes and three soluble proteins (Sar1p, Sec13p complex, and Sec23p complex). Vesicle formation requires GTP but can be driven by nonhydrolyzable analogs such as GMP-PNP. However, GMP-PNP vesicles fail to target and fuse with the Golgi complex whereas GTP vesicles are functional. All the cytosolic proteins required for vesicle formation are retained on GMP-PNP vesicles, while Sar1p dissociates from GTP vesicles. Thin section electron microscopy of purified preparations reveals a uniform population of 60-65 nm vesicles with a 10 nm thick electron dense coat. The subunits of this novel coat complex are molecularly distinct from the constituents of the nonclathrin coatomer involved in intra-Golgi transport. Because the overall cycle of budding driven by these two types of coats appears mechanistically similar, we propose that the coat structures be called COPI and COPII.

Base Sequence↗
PubMed1986

Outbreak of paralytic poliomyelitis in Finland: widespread circulation of antigenically altered poliovirus type 3 in a vaccinated population.

An outbreak of 9 cases of paralytic poliomyelitis and 1 non-paralytic case occurred in Finland between August, 1984, and January, 1985, after two decades of freedom from the disease attributable to a successful immunisation programme. During the outbreak poliovirus type 3 was isolated from the patients, from about 15% of healthy persons tested, and from sewage water. At least 100 000 persons were estimated to have been infected. With 1.5 million extra doses of inactivated poliovirus vaccine to children under 18 years of age and an oral poliovirus vaccine campaign covering about 95% of the entire population in February-March, 1985, the outbreak was halted in February, 1985. Impaired herd immunity to the epidemic strain of poliovirus type 3, which differed from the type 3 vaccine strains in both immunological and molecular properties, was important in the emergence of this outbreak. The inactivated poliovaccine that had been used in the vaccination programme was relatively weakly immunogenic, especially as regards the type 3 component. Whether continuous antigenic variation of poliovirus type 3 has wider epidemiological implications is not known.

Adolescent↗
PubMed1985

Variants of polyoma-transformed BHK21 cells unresponsive to fibronectin.

To investigate the relation between cell-substratum adhesion and cell-spreading we have isolated variants of anchorage-independent cells which fail to adhere to fibronectin. The variants are poorly adhesive both to fibronectin and serum, show dramatically altered morphology in culture and are unable to spread on any protein-coated surface yet tested.

Animals↗
PubMed1979

The leprous testis.

A clinical investigative study of 148 male leprous patients demonstrated the presence of testicular lesions in 35 cases. Semen analysis revealed marked oligo-athenozoospermia in 10 cases and azoospermia in 25 cases. Testicular biopsies from leprous testes showed different histologic patterns ranging from spermatogenic arrest to complete hyalinization of both seminiferous tubules and interstitial tissue. Histochemical staining for neurovascular supply revealed degenerative nerve change in addition to altered permeability of the testicular capillaries. There was good correlation between the results of semen analysis and histological and histochemical examination of testicular biopsies.

Adolescent↗
PubMed1979

Methotrexate and fertility in men.

The possible deleterious effects of folic acid antagonist methotrexate on the fertility potential have been investigated in 26 male psoriatic patients. Examination for semen, testicular histology, and spermatogenic function using radioactive phosphorus revealed that methotrexate had no unfavorable effect on male fertility. A long follow up of the patients and their offspring is needed to exclude the possible teratogenic effect of the drug.

Adult↗