Showing papers by "Cairo University published in 1993"

Mechanisms involved in the antiinflammatory effect of propolis extract.

Abstract: Propolis is a natural product produced by the honey bee. The extract contains amino acids, flavanoids, terpenes and cinnamic acid derivatives. In various in vitro models propolis extract was shown to inhibit platelet aggregation and to inhibit eicosanoid synthesis, suggesting that it might have potent antiinflammatory properties. A 13% aqueous extract was tested orally in three dose levels (1, 5 and 10 ml/kg) on the carrageenan rat paw oedema model and on adjuvant-induced arthritis in rats. In both models, the extract showed potent dose-related antiinflammatory activity, which compared well with that of diclofenac (as a reference standard). The extract was then tested on an isolated sensitized guinea pig lung preparation to study its effect on the release of prostaglandins, leukotrienes and histamine. It is concluded that propolis extract has potent antiinflammatory properties in vivo. Its activity can be well correlated with its effects on the release of various mediators of inflammation.

The Role of Vascular Mechanisms in the Development of Acute Equine Laminitis

Abstract: ACUTE LAMINITIS has long been attributed to factors or events that precede the onset of laminitis. Between 1759 and 1907 the overconsumption of grain, inflammation of the feet, suppression of perspiration (anhydrosis), excessive rest, excessive bleeding, road concussion, poor shoeing, unilateral weight bearing, sudden environmental temperature changes, prolonged standing (in the cold and aboard ships), diarrhea, and postpartum complications were all designated as causes. Today, commonly listed etiologic factors include ingestion of large amounts of grain, cold water, lush grass, or black walnut shavings, repeated concussion, endometritis or other severe infections, colic, exhaustion, stress, drug toxicities, and endocrine dysfunctions. At Texas A&M University (Table 1) the factors recorded as the cause presume a causal relationship between some preceding event and the acute laminitis. Logically, any event that precedes laminitis might be a cause, but etiologic validity depends on the definition of “cause” and the role that coincidence might have in the appearance of the disease.

Aperture realizations of exact solutions to homogeneous-wave equations

Abstract: Several new classes of localized solutions to the homogeneous scalar wave and Maxwell’s equations have been reported recently. Theoretical and experimental results have now clearly demonstrated that remarkably good approximations to these acoustic and electromagnetic localized-wave solutions can be achieved over extended near-field regions with finite-sized, independently addressable, pulse-driven arrays. We demonstrate that only the forward-propagating (causal) components of any homogeneous solution of the scalar-wave equation are actually recovered from either an infinite- or a finite-sized aperture in an open region. The backward-propagating (acausal) components result in an evanescent-wave superposition that plays no significant role in the radiation process. The exact, complete solution can be achieved only from specifying its values and its derivatives on the boundary of any closed region. By using those localized-wave solutions whose forward-propagating components have been optimized over the associated backward-propagating terms, one can recover the desirable properties of the localized-wave solutions over the extended near-field regions of a finite-sized, independently addressable, pulse-driven array. These results are illustrated with an extreme exampl—one dealing with the original solution, which is superluminal, and its finite aperture approximation, a slingshot pulse.

Towards the biological control of fungal and bacterial diseases of tomato using antagonistic Streptomyces spp.

Abstract: This investigation was designed to explore the potential of microbial antagonism in the control of some tomato diseases including bacterial, Fusarium and Verticillium wilts; early blight; bacterial canker. Three Streptomyces spp. were used: S. pulcher, S. canescens and S. citreofluorescens. The in vitro studies showed that an 80% concentration of the culture filtrate of either S. pulcher or S. canescens significantly inhibited spore germination, mycelial growth and spotulation of Fusarium oxysporum f.sp. lycopersici, Verticillium albo-atrum and Alternaria solani. The same concentration of filtrate of either S. pulcher or S. citreofluorescens was detrimental to the bacterial populations of Clavibacter michiganensis subsp. michiganensis and Pseudomonas solanacearum. The in vivo studies involved different treatments: soaking tomato seeds in filtrate of the antagonist prior to sowing, inoculation of the soil with the antagonist 7 days before sowing, and coating of tomato seeds with spores of the antagonist before sowing. The seed-coating treatment was the most effective in controlling all the pathogens at 42 and 63 days after sowing. Soil inoculation with the antagonist 7 days prior to sowing was less effective in controlling the tomato pathogens as compared to seed-coating. The seed-soaking treatment was the least effective in controlling the diseases concerned. The results also revealed that seed-coating with antagonistic Streptomyces spp. significantly improved tomato growth.

Energy-momentum complex in Møller's tetrad theory of gravitation

Abstract: Moller's tetrad theory of gravitation is examined with regard to the energymomentum complex. The energy-momentum complex as well as the superpotential associated with Moller's theory are derived. Moller's field equations are solved in the case of spherical symmetry. Twodifferent solutions, giving rise to thesame metric, are obtained. The energy associated with one solution is found to be twice the energy associated with the other. Some suggestions to get out of this inconsistency are discussed at the end of the paper.

Polytetrafluoroethylene injection for the treatment of partial fecal incontinence.

Abstract: Perianal injection of polytetrafluoroethylene (Teflon or Polytef) paste was used in the treatment of 11 patients with partial fecal incontinence which followed internal sphincterotomy in 7 patients and was idiopathic in 4 All patients had been incontinent for more than 4 years, and had failed to respond to conservative measures 5 ml of Polytef paste were injected, without anesthesia, in the rectal neck submucosa, above the pectinate line at each of the 3 and 9 o'clock positions Patients were followed for 18 to 24 months They were categorized into 3 scores: 1, cured; 2, improved, and 3, no change Long-term cure (score 1) occurred in 454% after the 1st injection and in 636% after the 2nd injection 364% showed partial improvement (score 2) No failures occurred Improvement is believed to be due to the increase in rectal neck pressure produced by the cushion-effect of the polytef submucosal injection The technique is simple, easy and without complications It is performed on an outpatient basis

Role of warm-water bath in anorectal conditions. The "thermosphincteric reflex".

Abstract: Why anorectal pain is relieved by sitting in a warm-water bath was investigated in 18 healthy volunteers and 28 patients with painful anorectal disease (18 patients with fissures and 10 with hemorrhoids). Investigations consisted of measuring rectal and interstitial sphincter temperature, rectal and rectal neck pressures, and electromyographic activity of both the external and internal anal sphincters before and after the subjects sat in a warm-water bath at temperatures of 40, 45, and 50 degrees C for 10 min each time. Pain relief was more evident and lasted longer at higher bath temperatures. The rectal and interstitial sphincter temperatures were unchanged before and after bath in both the healthy volunteers and patients. The rectal neck pressure and internal and sphincter electromyographic activity dropped significantly in the bath, but increased gradually to pretest levels 25-70 min after exiting the bath. The higher the bath temperature, the greater the drop in rectal neck pressure and internal sphincter EMG activity, and the longer the time needed to return to pretest levels. Pain relief after Sitz bath seems to be the result of internal anal-sphincter relaxation with a resulting diminution of the rectal neck pressure. The relaxation of the internal sphincter following the warm bath postulates a relationship, but direct action was ruled out. A neural pathway through a "thermosphincteric reflex" seems most likely.

Vaginocavernosus reflex. Clinical significance and role in sexual act.

Abstract: The action and clinical significance of the vaginocavernosus reflex was studied in 17 healthy women with a mean age of 36.6 years. The response of the bulbo- and ischiocavernosus muscles to rapid vaginal distension by balloon was recorded by a needle electrode inserted in each muscle and displayed on the screen of an EMG apparatus. The two cavernosus muscles contracted on vaginal distension; the amplitude of contraction increased with the increase of volume of vaginal inflation. The reflex contraction was not evoked after frequent successive or slow inflations or upon inflation of the anesthetized vagina. The latency of the reflex decreased with increased volume of vaginal inflation. The reflex cavernosus muscle contraction on vaginal distension during the sexual act seems to enhance both the clitoris and penile erection. This is believed to result from the compression exerted on both the deep dorsal vein of the penis and the erectile cavernous tissue. Also, cavernosus muscles contraction may help to milk the semen in the penile urethra into the vagina while the penis is being withdrawn from the vagina after ejaculation. Furthermore, vaginal distension by the fetal head during delivery induces cavernosus muscles contraction, which is suggested to support the head during its descent and prevent vaginal and perineal tears.

The mutagenicity of Gramoxone (paraquat) on different eukaryotic systems.

Abstract: The possible mutagenicity of the herbicide Gramoxone was evaluated using five different living systems: Allium cepa, Vicia faba, yeast, Drosophila melanogaster and human lymphocytes. The results indicate that Gramoxone has mutagenic activity at the cytological level in Allium cepa, Vicia faba and human lymphocytes. All doses were effective in inducing chromosomal abnormalities and a clear dose-response relationship was observed in the various cytological tests. Analysis of chromosomal abnormalities revealed that this herbicide displays clastogenic and turbagenic activities. At the gene mutation level Gramoxone induced gene conversion at the trp-5 locus and reversion at the ilv locus in Saccharomyces cerevisiae. In Drosophila melanogaster, Gramoxone proved to be mutagenic to germ cells and induced a high frequency of sex-linked recessive lethals (SLRL). At the protein level, Gramoxone had detectable mutagenic effects on the genetic background of two enzymes, Adh and Est-6. Gramoxone should be considered a mutagenic herbicide.

A study of infraorbital foramen, canal and nerve in adult Egyptians.

Abstract: The infraorbital foramen, canal and nerve were examined in 30 Egyptian adult skulls and 15 adult human cadavers. The infraorbital foramen was single in 90% of cases and double in 10%. It was oval in 65% of cases and round in the remaining cases. It was directed downward, forward and medially in 60%, downward in 25% and medially in 15% of cases. The distance from the centre of the foramen to the inferior orbital margin was 6.1 +/- 2.4 mm and to the lateral nasal border was 14.7 +/- 2.7 mm. The infraorbital foramen was opposite the 2nd maxillary premolar in 50% of cases, opposite the 1st premolar in 15% and between the 1st and 2nd premolar teeth in 15% of cases. The length of the infraorbital canal was 28.8 +/- 2.9 mm and it showed an infraorbital groove in 60% of cases, a complete roof in 25% and a deficient roof leaving a short bony bridge in 15% of cases. The anterior superior alveolar nerve arose either from the middle third of the infraorbital nerve (in 10 out of 15 cases) or from its anterior third in the remaining 5 cases. The middle superior alveolar nerve was not apparent in 8 cases and it arose from the middle third of the infraorbital nerve in the remaining 7 cases. Radiographic study of the infraorbital foramen and canal on 15 adult dry skulls were also done using 3 different views for each skull. The panoramic view showed to be better than either of the lateral or the postero/anterior view.

Lupus miliaris disseminatus faciei--pathologic study of early, fully developed, and late lesions.

Abstract: Background. Lupus miliaris disseminatus faciei is a chronic inflammatory disorder, which affects adults of both sexes. Methods. This study included 25 patients with lupus miliaris disseminatus faciei. Three biopsies, representing early, fully developed, and late lesions, were taken from each patient. Results. Histopathologic examination of the different lesions revealed that in early lesions, all of them showed superficial perivascular and periappendigeal cellular infiltrate composed mostly of lymphocytes and few histiocytes with occasional neutrophils. The fully developed lesions showed a sarcoidal granuloma only (40%), sarcoidal granuloma with abscess (24%), sarcoidal granuloma around areas of caseation necrosis (20%), and a mixture of sarcoidal and tuberculoid granulomas (16%). Conclusions. All the late lesions showed extensive fibrosis especially in the perifollicular areas. Scattered lymphocytes, histiocytes and neutrophils were present within the fibrotic areas. A possible explanation of the pathogenesis is discussed.

A least-squares minimization approach to depth determination from moving average residual gravity anomalies

Abstract: We have developed a least-squares minimization method to estimate the depth of a buried structure from moving average residual gravity anomalies. The method involves fitting simple models convolved with the same moving average filter as applied to the observed gravity data. As a result, our method can be applied not only to residuals but also to the Bouguer gravity data of a short profile length. The method is applied to synthetic data with and without random errors. The validity of the method is tested in detail on two field examples from the United States and Senegal.

Hyperthermic potentiation of cisplatin cytotoxicity on solid Ehrlich carcinoma.

Abstract: BACKGROUND Hyperthermia produces marked effects on many biochemical parameters of tumor cells and has been reported to potentiate the effect of many drugs. We therefore evaluated the possible synergistic effect between hyperthermia and cisplatin against solid Ehrlich carcinoma. The study was based on the measurement of some biologic characteristics in tumor tissues, namely: DNA, RNA, and protein content and their rate of synthesis as parameters for nuclear damage; total lipids and cholesterol as parameters for membrane damage; acid-phosphatase and acid-ribonuclease as parameters for lysosomal damage; and tumor volume as a direct parameter for tumor growth. METHODS Treatment of solid Ehrlich carcinoma by hyperthermia at 43 degrees C for 30 min for 3 successive days produced a 41.5% decrease in tumor volume, as well as a significant decrease in nucleic acids, protein contents and their rate of synthesis, in total lipids and cholesterol, and in acid-phosphatase and acid-ribonuclease. Chemotherapeutic management of the tumor by 5 mg/kg x 3 of cisplatin alone showed a continuous increase in tumor volume but at a lower rate than that of the untreated control. However, when cisplatin was given 1 h prior to hyperthermia, the tumor volume was significantly decreased by 82.6%. RESULTS The effects observed on all the investigated parameter were intensified when cisplatin was combined with hyperthermia. The results obtained suggest that hyperthermia may enhance the penetration of cisplatin to its target site inside the tumor cells due to a membrane-damaging effect. The enhanced lethality of cisplatin on tumor cells may also be due to the inhibition of DNA repair processes by hyperthermia.

Intralesional Cryosurgery A New Technique Using Cryoneedles

Abstract: A new method for applying cryosurgery in depth has been performed in a trial in order to achieve more effectiveness and avoid many of the disadvantages of conventional techniques. A needle is introduced into the skin from one point and runs through the deeper tissues of the lesion, appearing at the surface on the opposite border. A cryogen is then passed through one end of the needle and vents to the atmosphere from the opposite end. An ice cylinder is formed around the embedded part of the needle within the deeper tissues. The distance of extension of freezing can be estimated by insertion of thermocouple needles as well as by the degree of extension of the whitish ice balls formed around the points of contact between the skin surface and the visible portions of the needle. New varieties of needles have been developed to facilitate improved efficacy in achieving better depth of freeze. The needles are angled, curved, and hook-shaped. Some are partially insulated to better localize the direction of freezing. The process was very practical, and effectively eradicated 85% of epidermal lesions after one freeze; 15% needed additional sessions as did deeper dermal lesions.

Toxicity of cyanobacteria to mosquito larvae―Screening of active compounds

Abstract: To study toxicity of 76 laboratory-grown strains of planktonic cyanobacteria to mosquito larvae, hydrophilic and lipophilic cell-free extracts of cyanobacteria were incubated with larvae of the Aedes aegypti mosquito and death percentages were followed during 2 days. Toxicity was clearly associated with hepato - and neurotoxins of the samples. A strain of Microcystis aeruginosa was most effective, and caused death of the larvae due to a single hepatotoxin. Pure mammalian neurotoxin, anatoxin-a, was also toxic, and probably acted as a neurotoxin with the mosquito larvae.

Molecular characterization of β‐thalassemia in Egyptians

Abstract: We sought to determine the spectrum of mutations producing beta-thalassemia in Egypt using genomic PCR and a variety of mutation-screening procedures. Thirty-four beta-thalassemia and three Hb S/beta-thalassemia patients originating from different regions of Egypt were studied, and the causative mutation was found in 69 of 71 (97%) beta-thalassemia genes. Four mutations accounted for 78% of beta-thalassemia genes in this population; IVS-1, nt 110 (41%), IVS-1 nt 6 (13%), IVS-1, nt 1 (13%), and IVS-2, nt 848 (11%). The latter allele, a C-A mutation at the third nucleotide of an acceptor site consensus sequence, has been described previously only in one Egyptian, one Iranian, one Tunisian, and one Black American patient. Nine other alleles each accounted for 1-3% of beta-thalassemia genes. Among these was one codon 27 allele (Hb Knossos), two frameshift 106/107 alleles previously seen only in a Black American, and a rarely observed mutation in the distal promoter region of the beta-globin gene, -87 (C-A). Our results suggest that from a molecular genetic standpoint a beta-thalassemia prevention program based on carrier screening and prenatal diagnosis can be implemented in Egypt. In couples at risk for beta-thalassemia, the causative mutation should be identifiable in both members in 92% and in one member in the remaining 8%.

Correlations between Aharonov-Bohm effects and one-dimensional subband populations in GaAs/AlxGa1-xAs rings.

Abstract: The Aharonov-Bohm (AB) interference patterns in ring-shaped conductors are usually dominated by random features. The amplitude of the oscillations is random from sample to sample and from point to point on the magnetic field axis owing to random scattering of the electron trajectories by impurities within the wires. We report experiments on devices made wet etching and global gates, which have shown major progress towards removing the random features. In loops that exhibit ballistic conductance plateaus and cyclotron orbit trapping at 4.2 K, the random pattern of AB oscillations (observed for T<0.1 K) can be replaced by a much more ordered one-especially if only a few transverse modes are populated in the ring

A comparative study of azithromycin and amoxycillin in paediatric patients with acute otitis media

Abstract: In this open study, a three-day regimen of azithromycin (single daily dose of 10 mg/kg) was compared with a ten-day regimen of amoxycillin paediatric suspension (30 mg/kg/day in three divided doses; children > 20 kg received 250 mg tid daily) in 154 children (aged 2-12 years) with a clinical diagnosis of acute otitis media (13 recurrent). Full clinical, bacteriological and laboratory safety assessments were performed during and after the study. Of the 77 azithromycin patients, 61 (79%) were considered cured, 15 (19%) improved and one (1%) failed, compared with 45 (58%) cured, 28 (36%) improved and four (5%) failed among the 77 amoxycillin patients. Excluding from analysis the 13 patients with recurrent otitis media, azithromycin was found to be significantly superior to amoxycillin (P = 0.003). The incidence of side-effects was low, with only two (3%) and three (4%) patients reporting adverse events with azithromycin and amoxycillin, respectively. These were gastrointestinal in nature and of mild or moderate severity, except for one case of severe diarrhoea in the amoxycillin group. No treatment-related abnormalities in the laboratory safety tests were observed, and no patients withdrew from therapy. A three-day regimen of azithromycin was therefore shown to be more effective than, and as well tolerated as, amoxycillin in the treatment of children with acute otitis media.

Constipation. Pathogenesis and management.

Abstract: Constipation is a collective term for different manifestations of different aetiology, pathology and treatment. It can be a symptom of organic disease or may disclose a colonic or anorectal functional disorder of unknown aetiology--this is called chronic idiopathic constipation (CIC). CIC could be due to colonic or anorectal dysmotility. The latter presents as rectal inertia or outlet obstruction. Outlet obstruction manifests with excessive straining (strainodynia), although stools are soft and bulky. Four types of strainodynia can be identified: band, sphincter, levator and detrusor. Idiopathic infrequent defecation (oligofaecorrhoea) is revealed by hypertrophy and degenerated nerve plexus of the internal anal sphincter. It presents clinically with 'cone anus'. The 'mass squeeze contraction' theory describes rectal motility; the wave starts at the rectosigmoid junction (RSJ) and spreads distally. A 'pacemaker' was suggested to exist at the RSJ, organising rectal motility. Indeed, studies on electromechanical rectal activity revealed pacesetter and action potentials originating at the RSJ. Faecoflowmetry and water enema tests are new methods for investigating anorectal dysmotility, and reflexometry is important in assessment. The treatment of CIC is problematic and controversial. However, the patient should be given the chance to try pharmacological treatment at the start before embarking on surgery. Biofeedback may be helpful, especially in outlet obstruction constipation. Sphincter myotomy and myectomy, partial rectal resection and colectomy have been used, with variable results. Medical treatment with a fibre-rich diet or orally or rectally administered laxative agents may be indicated in the treatment of constipation, especially when a cause can not be identified. However, it is important to stress that the untoward effects which may result from laxative abuse could be greater than those of constipation.

Lexical analysis of inflected Arabic words using exhaustive search of an augmented transition network

Abstract: This paper presents a lexical analyser for inflected Arabic words. An augmented transition network (ATN) technique was used to represent the context-sensitive knowledge about the relation between a stem and inflectional additions. An exhaustive-search algorithm is developed to traverse the ATN, generating all possible interpretations of an inflected Arabic word. The arcs of the ATN are augmented with rules containing conditions and actions. More than one rule is associated with some arcs. The states of the ATN are represented by Pascal procedures.