Structural and functional adaptation of the lingual papillae of the Egyptian fruit bat (Rousettus aegyptiacus): specific adaptive feeding strategies.

BACKGROUND: The current investigation was aimed to clarify the correlations between the feeding strategy and lingual structure of the Egyptian fruit bat captured from the Egyptian east desert. MATERIALS AND METHODS: The current work was performed on 12 adult Egyptian fruit bats that were observed grossly and with the help of the stereo, light, and scanning electron microscope. There were three types of the lingual papillae: one mechanical (filiform) and two gustatory (fungiform and circumvallate). RESULTS: There were seven subtypes of filiform papillae recognised on the seven lingual regions. There were few fungiform papillae distributed among the filiform papillae on the lingual tip and two lateral parts of apex and body while fungiform papillae were completely absent in the median part. There were three circumvallate papillae. The central bulb of circumvallate papillae was surrounded by one layer of two segmented circular pad. The lingual tip had cornflower-like and diamond-shaped filiform papillae. CONCLUSIONS: Histochemical results revealed that the lingual glands showed a stronger Alcian Blue (AB)-positive reaction and gave dark blue colour, while the reaction for the periodic acid-Schiff (PAS)-stain was negative. Also, the glands exhibited a blue colour as an indication of positive AB reactivity with combined AB-PAS staining.

Ultrastructural features on the oral cavity floor (tongue, sublingual caruncle) of the Egyptian water buffalo (Bubalus bubalis): gross, histology and scanning electron microscope.

BACKGROUND: The present work was focused on the evaluation of morphological characteristics of the lingual caruncles and tongue with its papillae of Egyptian water buffalo (Bubalus bubalis) using gross examination, light and scanning electron microscopy. MATERIALS AND METHODS: The ventral surface of the sublingual caruncle carried a small opening of the duct of both monostomatic and mandibular salivary gland. The lingual mucosa of dorsal, lateral border and, to some extent, of ventral surface of apex had lingual papillae (filiform, fungiform), while the lingual mucosa of the lingual body especially at torus linguae had conical papillae, but circumvallate papillae observed at the caudal part of body and root. The dorsal surface of the apex and body carried numerous long, thread-like, with blunt apex, caudally directed filiform papillae that covered with keratinised scales without secondary papillae. RESULTS: The degree of keratinisation classified filiform papillae into rostral part of high keratinisation and caudal of less keratinisation. Conical papillary surface carried exfoliated epithelium with longitudinal groove on its rostral surface and carried secondary papillae. Fungiform papillae were scattered among filiform papillae on the dorsal and ventral surface of the apex and its convex surface had exfoliated keratinised epithelium. Circumvallate papillae were surrounded by circular deep groove bordered by vallum that carried small secondary papillae that ended into the primary groove. Taste buds of circumvallate papillae opened in the lateral lining epithelium facing the groove. CONCLUSIONS: Von Ebner's glands were observed in computed tomography under papillae especially toward the groove and their ducts open into the base of the groove.

Immunohistochemical evaluation of interleukin-23 and cyclooxygenase-2 in the muscles of mice infected with Trichinella spiralis.

The course of Trichinella (T.) spiralis infection includes intestinal and muscle phases. The aims of this work were to evaluate IL-23 and cyclooxygenase-2 (COX-2) by immunohistochemistry in the muscles of T. spiralis infected mice in a time-course study and to correlate their level with the serum levels of IL-23, IFN-γ, IL-4 and IL-10 cytokines. The mice were divided into an un-infected control group (UC) (10 mice) and 5 infected mouse groups (each 10 mice/group. Each mouse was infected with 200 T. spiralis larvae) and sacrificed on days 7, 14, 21, 28 and 35 post-infection (dpi). IL-23 showed weak expression (+1) on the 21st dpi, then it became moderately expressed (+2) on the 28th dpi and on day 35 pi, the immunoreactivity was strong (+3). COX-2 expressed weakly on 14 dpi, while the other mouse groups (21, 28 and 35) showed strong (+3) expression. IL-23 serum concentrations increased gradually in a significant pattern, in comparison to that of UC mice, from the 21st dpi to the end of the experiment. IFN-γ increased gradually and was significantly higher than those of UC mice from the 7th dpi, reached its maximum level on the 21st dpi, after which it decreased non-significantly. IL-4 up-regulated significantly in all infected groups in comparison to UC mice achieving its highest level on the 21st dpi and decreased after that. IL-10 increased significantly on the 7th dpi, but dropped at the 14th dpi, then reached its peak on the 21st dpi, and decreased again on the 28th and 35th dpi. In conclusion, T. spiralis infection caused increased expression of IL-23 and COX-2 in the muscle of infected mice, the effect being strongest on the 35th day. Also, the infection induced a mixed Th1/Th2 profile with a predominance of Th2 at the early muscle phase, after which the immune repose became mainly Th2.

Immunization with adult Schistosoma mansoni tegument, treated with sub-curative praziquantel, partially protects mice against the infection.

The tegument of schistosomes is a source of many potential anti-Schistosoma vaccine molecules. This work aimed to assess the protective effects of the adult Schistosoma mansoni tegument treated (TT) with sub-curative praziquantel (PZQ), whether in vivo (in vivo TT) or in vitro (in vitro TT), in murine schistosomiasis. In vitro TT and in vivo TT showed great similarity, and they differed from untreated tegument antigen (Teg) in terms of quantity and quality of protein bands on SDS-PAGE. Two immunization trials were performed, each with 50 mice, divided randomly into five groups of 10 mice each: (1) uninfected control mice (UC), (2) infected mice given phosphate buffer saline + adjuvant (PBS + adjuvant), (3) infected, Teg vaccinated, (4) infected, in vivo TT vaccinated, and (5) infected, in vitro TT vaccinated. All the immunizations with antigens induced mixed Th1/Th2 immune responses, as indicated by significantly high (P < 0.001) specific IgG2a and IgG1 levels, with Th1 predominating, as shown by a diminished IgG1/IgG2a ratio, as well as a high serum concentration of IFN-γ, an absence of IL-4 and increased IL-10. In vitro TT gave the most pronounced response. With respect to reduction of total worm burden, relative to PBS + adjuvant mice, in vitro TT achieved the highest significant (P < 0.001) results, followed by in vivo TT and Teg (51.8-57.04%, 44.6-50.2% and 35.2-39.3%, respectively). In scanning electron microscopy studies, all the tested antigens caused tegumental changes in adult worms, with the worst occurring with in vitro TT, such as retracted ventral sucker, an effect on the gynaecophoric canal, and changes to tubercles. In conclusion, in vitro TT, which is cheap to prepare, could be a potential vaccine against S. mansoni.

Effects of Callistemon citrinus aqueous extract on prepatent and patent infections with Schistosoma mansoni in experimentally infected mice.

Schistosomiasis is a chronic debilitating parasitic disease that causes hepatic damage and is known to be endemic in developing countries. Recent control strategies for schistosomiasis depend exclusively on chemotherapeutic agents, specifically praziquantel. Unfortunately, praziquantel has low efficacy in the early phase of infection, and resistance to treatment is increasingly reported. The aim of this work was to find an alternative treatment by assessing the in vivo activity of aqueous extract of Callistemon citrinus against Schistosoma mansoni in both prepatent and patent phases in experimentally infected mice. The study was conducted on 80 male BALB/c albino mice divided into eight groups. Callistemon was administered at a dose of 200 mg/kg on days 14 and 45 post infection as a single therapy and in combination with praziquantel. Porto-mesenteric worm burden, hepatic and intestinal egg counts, hepatic granuloma number and diameter, and oogram pattern were assessed to evaluate the anti-schistosomal properties of C. citrinus. Liver enzymes and total bilirubin were tested to assess hepatoprotective effects. Results revealed that the use of C. citrinus was associated with a significant decrease in worm burden and tissue egg load together with an increased percentage of dead eggs. In addition, there was a significant reduction in granuloma formation. Callistemon also led to a significant improvement in liver function. The best results were obtained when C. citrinus was given in the prepatent phase of infection and when combined with praziquantel. Although the effects of C. citrinus are considered to be promising, further studies using different extracts, active ingredients and doses are needed.

Regulation of Slo potassium channel alternative splicing in the pituitary by gonadal testosterone.

Slo gene-encoded BK potassium channels are prominent in both adrenomedullary and pituitary tissues. At one alternative splicing site, both tissues express variants with and without the optional 'STREX' exon. In adrenal chromaffin cells, this splicing choice, which has important ramifications for cell excitability, has been shown to be regulated by steroid hormones, including glucocorticoids and adrenal androgens. Moreover, striking sex differences are seen between male and female tree shrews. Here, we test the hypothesis that gonadal testosterone regulates splicing in these tissues. No significant sex differences were found in rats, in either adrenals or pituitaries. In the adrenal medulla, prepubertal castration in male rats increased the relative abundance of STREX transcripts slightly, but not significantly, as measured several weeks after puberty. However, castration substantially decreased STREX representation in the rat pituitary. Silastic implants of testosterone inserted at castration prevented this STREX decline. In postpubescent males, castration or T implants had less effect. Thus, we report (i) steroidal regulation of Slo splicing in the pituitary and (ii) participation of the male gonads in this regulation.

Microdomains of high calcium are not required for exocytosis in RBL-2H3 mucosal mast cells.

We have previously shown that store-associated microdomains of high Ca(2+) are not essential for exocytosis in RBL-2H3 mucosal mast cells. We have now examined whether Ca(2+) microdomains near the plasma membrane are required, by comparing the secretory responses seen when Ca(2+) influx was elicited by two very different mechanisms. In the first, antigen was used to activate the Ca(2+) release-activated Ca(2+) (CRAC) current (I(CRAC)) through CRAC channels. In the second, a Ca(2+) ionophore was used to transport Ca(2+) randomly across the plasma membrane. Since store depletion by Ca(2+) ionophore will also activate I(CRAC), different means of inhibiting I(CRAC) before ionophore addition were used. Ca(2+) responses and secretion in individual cells were compared using simultaneous indo-1 microfluorometry and constant potential amperometry. Secretion still takes place when the increase in intracellular Ca(2+) occurs diffusely via the Ca(2+) ionophore, and at an average intracellular Ca(2)+ concentration that is no greater than that observed when Ca(2+) entry via CRAC channels triggers secretion. Our results suggest that microdomains of high Ca(2+) near the plasma membrane, or associated with mitochondria or Ca(2+) stores, are not required for secretion. Therefore, we conclude that modest global increases in intracellular Ca(2+) are sufficient for exocytosis in these nonexcitable cells.

Lawrence-Seip syndrome: report of a case from Egypt.

A case of acquired total lipodystrophy (Lawrence-Seip syndrome) is reported in a 17-year-old Egyptian girl. The patient had generalized lipodystrophy, eruptive xanthomas, diabetes mellitus, and severe osteoporosis.

Correlating Ca2+ responses and secretion in individual RBL-2H3 mucosal mast cells.

The role of Ca2+ in stimulus-response coupling in nonexcitable cells is still not well understood. The Ca2+ responses of individual cells are extremely diverse, often displaying marked oscillations, and almost nothing is known about the specific features of these Ca2+ signals that are important for the functional response of a cell. Using the RBL-2H3 mucosal mast cell as a model, we have studied the temporal relationship between changes in intracellular Ca2+ and serotonin secretion at the single-cell level using simultaneous indo-1 photometry and constant potential amperometry. Secretion in response to antigen never occurs until intracellular Ca2+ is elevated, nor is it seen during the first few oscillations in Ca2+. Exocytotic events tend to be clustered around the peaks of oscillations, but excellent secretion is also seen in cells with sustained elevations in Ca2+. Ca2+ release from stores in the absence of influx fails to elicit secretion. If refilling and continued release of Ca2+ from stores is prevented with thapsigargin, Ca2+ influx can still trigger secretion, suggesting that store-associated microdomains of Ca2+ are not required for exocytosis. Our findings demonstrate the importance of an amplitude-encoded Ca2+ signal and Ca2+ influx for stimulus-secretion coupling in these nonexcitable cells.

Basal cell carcinoma in Qatar.

BACKGROUND: There is an increasing incidence of basal cell carcinoma (BCC) and skin cancer in general among various countries, where the sun is implicated as an important causative factor. METHODS: Results of clinical and histopathologic examination and the incidence rate of BCCs were recorded over a period of 5 years at Hamad Medical Corporation, Doha, Qatar. RESULTS: Basal cell carcinoma is the commonest skin cancer in Qatar. The average annual incidence per 100,000 residents of working manpower, standardized to the 1986 census, is 9.9 for both sexes and at all ages. Expatriates formed the highest proportion and of these, Europeans were predominant. The tumor was more frequent in men, on sun-exposed areas, was mostly of the nodular and infiltrative type, and occurred in the 3rd, 4th, and 5th decades. As a whole, persons with relatively heavily pigmented skin constituted 66.7% of the patients. CONCLUSIONS: Intense sunlight exposure during outdoor work and leisure activities in Qatar puts residents at increased risk for nonmelanoma skin cancer, even in persons with relatively pigmented skin.

Fatal anaphylactic reaction to diclofenac.

A case of apparent anaphylactic reaction to diclofenac sodium (Voltaren) is reported. A 45-year-old man collapsed 15 min after intramuscular injection of diclofenac for treatment of low back pain. Twenty minutes following successful resuscitation, he went into coma from which he never recovered and was pronounced dead on the following day. To our knowledge, this is the first reported case of anaphylactic reaction to diclofenac.

Leprosy in Qatar.

Clinical and histopathologic features of 104 cases of leprosy diagnosed between 1982 and 1989 in the State of Qatar were studied. There were 88 male (84.6%) and 16 (15.4%) female patients aged 18 to 64 years. Eighty-four of the cases were diagnosed during the initial mandatory medical screening on arrival to Qatar. Almost all (103) were expatriates and only one 50-year-old woman was a Qatari. Indians formed the largest group (60.6%), followed by Bangladeshi (6.7%), Pakistani (5.8%), and others. The majority of cases were classified as lepromatous (43.3%) or tuberculoid (43.3%). Although Qatar is a relatively leprosy-free country, the influx of a large number of workers from developing countries seeking employment forms a potential public health hazard.

Klippel-Trenaunay syndrome.

An unusual and extreme case of Klippel-Trenaunay syndrome is presented. The patient has an extensive capillary hemangioma involving the right side of the body, increases in the length and girth of the right lower limb, gross varicosities of the superficial venous system, and complete absence of the deep venous system of the right lower extremity, with suprapubic shunt of the venous blood to the contralateral external iliac vein. Secondary manifestations are increased sweating and compensatory scoliosis.