Charles S. Bakheit
Sultan Qaboos University
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Featured researches published by Charles S. Bakheit.
Mycopathologia | 2002
Abdulkadir E. Elshafie; Tahiya A. Al-Rashdi; Saif N. Al-Bahry; Charles S. Bakheit
One hundred and five samples of seven spices (cumin, cinnamon, clove, black pepper, cardamom, ginger, and coriander) were purchased from five popular companies in the Sultanate of Oman. The spices were surveyed for the mycoflora and aflatoxins. Twenty fungal species were isolated in which Aspergillus flavus , A. niger . Penicillium , Rhizopus , and Syncephalastrum racemosum were the most dominant. When colony forming units per gm (cfu/gm) of fungi were compared, significant differences were found among spices and companies. Of the seven spices studied, clove was found to be the least contaminated, while cumin was the most contaminated. None of the 15 selected samples of the spices contaminated by A. flavus were found to contain aflatoxins. Nevertheless, nine isolates (45%) of the twenty A. flavus strains screened for aflatoxins were aflatoxigenic. The moisture content of most of the spices was below the maximum standard limit. The results showed that the spices were contaminated by some fungi that might constitute health hazards for humans.
General and Comparative Endocrinology | 2013
Issa Sulaiman Al-Amri; I.Y. Mahmoud; Colin P. Waring; Abdulaziz Y. Alkindi; Tabisam Khan; Charles S. Bakheit; Kamla M. Al-Mawali
The annual testicular cycle of the house gecko Hemidactylus flaviviridis in Oman was studied. Plasma testosterone (T), estradiol (E2) and progesterone (P) concentrations were measured using a sensitive HPLC-MS/MS detection technique. The ultrastructural steroidogenic features in Sertoli and Leydig cells, which were the major source of steriodogenesis, were examined, using transmission electron microscopy (TEM). In addition, progesterone receptors (PR) were examined throughout the testicular cycle, using an immunohistochemical technique. The steroidogenic ultrastructural features were characterized by the presence of smooth endoplasmic reticulum (SER) in the form of cisternal whorls and tubular cisternae, presence of swollen vesiculated mitochondria, and association between SER, mitochondria and lipid droplets. The rise in plasma steroid concentrations was closely associated with the development of the ultrastructural features and PR expression in Leydig and Sertoli cells. During the active phase (November-May), there was a significant rise in plasma steroid concentrations (P<0.05) related to well developed steroidogenic features and strongly expressed PR. During the quiescent phase (June-August) there was a significant decline in plasma steroid concentrations, undeveloped steroiodogenic features and weakly expressed PR. The Renal Sexual Segment (RSS) was fully developed during the active phase. The data provides strong evidence that these ultrastructural steroidogenic features were related to the plasma sex steroid concentrations during the testicular cycle.
General and Comparative Endocrinology | 2012
Issa Al-Amri; I.Y. Mahmoud; Colin P. Waring; Abdulaziz Y. Alkindi; T. Khan; Charles S. Bakheit
A comprehensive study of the annual ovarian cycle in the house gecko, Hemidactylus flaviviridis, was conducted in Oman. Circulating estradiol (E(2)), progesterone (P), and testosterone (T) were measured during the active and inactive phases of the cycle. The steroid levels were related to the steroidogenic ultrastructural features such as the abundance of smooth endoplasmic reticulum (SER), the presence of cisternal whorls, and close association of lipid droplets with swollen vesiculated mitochondria and SER. The steroids were measured using a sensitive detection technique HPLC-MS/MS. E(2) levels began to rise in January at the onset of vitellogenesis and continued to rise between February and May relative to ovulation, postovulation, gravidity and oviposition. Afterwards, E(2) remained low during the inactive phase (June-December). P levels increased significantly in March and peaked in April, which coincided with luteinization. P levels began to decline relative to luteolysis (May-June). Afterwards, it remained low throughout the inactive phase. T levels rose significantly in March-April coinciding with vitellogenesis, but decreased rapidly and significantly in May and remained low during the inactive phase. Progesterone receptors (PR), identified using immunohistochemistry, were strongly expressed during the breeding period, but were absent during the non-breeding period. The appearance of the steroidogenic ultrastructural features in the preovulatory and lutein granulosa cells was correlated with the significant rise in the three steroid levels and the PR. As the steroid levels declined, the granulosa cells underwent a general degeneration and disruption of the associated steroidogenic features.
Chelonian Conservation and Biology | 2006
A.Y.A. AlKindi; I.Y. Mahmoud; Aziz A. Al-Habsi; Saif N. Al-Bahry; Hamad M. Al-Gheilani; Charles S. Bakheit
ABSTRACT Beaches at Ras Al-Hadd Reserve, Oman, share common physical features ideal for nesting green turtles (Chelonia mydas). However, human activities related to commercial fishing and coastal development impact nesting. Beaches with hills as a backdrop and with minimal human activities were the primary nesting sites at the reserve. During peak nesting season (monsoon/wet period), the mean number of excavation attempts was equal between oviposited and nonoviposited turtles. During nonpeak season (dry period), the mean number of excavation attempts was significantly higher in nonoviposited turtles than in oviposited turtles, and insufficient sand moisture frequently resulted in one or several nest collapses and oviposition failure.
Scientific Reports | 2017
Adviti Naik; Noura Al-Zeheimi; Charles S. Bakheit; Marwa Al Riyami; Adil Al Jarrah; Mansour S. Al Moundhri; Zamzam Al Habsi; Maysoon Basheer; Sirin A. Adham
Circulating plasma and peripheral blood mononuclear (PBMCs) cells provide an informative snapshot of the systemic physiological state. Moreover, they provide a non-invasively accessible compartment to identify biomarkers for personalized medicine in advanced breast cancer. The role of Neuropilin-1 (NRP-1) and its interacting molecules in breast tumor tissue was correlated with cancer progression; however, the clinical impact of their systemic levels was not extensively evaluated. In this cross-sectional study, we found that circulating and tumor tissue expression of NRP-1 and circulating placental growth factor (PlGF) increase in advanced nodal and metastatic breast cancer compared with locally advanced disease. Tumor tissue expression of NRP-1 and PlGF is also upregulated in triple negative breast cancer (TNBC) compared to other subtypes. Conversely, in PBMCs, NRP-1 and its interacting molecules SEMA4A and SNAI1 are significantly downregulated in breast cancer patients compared to healthy controls, indicating a protective role. Moreover, we report differential PBMC expression profiles that correlate inversely with disease stage (SEMA4A, SNAI1, PLXNA1 and VEGFR3) and can differentiate between the TNBC and non-TNBC tumor subtypes (VEGFR3 and PLXNA1). This work supports the importance of NRP-1-associated molecules in circulation to characterize poor prognosis breast cancer and emphasizes on their role as favorable drug targets.
Zoology in The Middle East | 2005
I.Y. Mahmoud; A.Y.A. AlKindi; Taher Ba-Omar; Sultan Al-Siyabi; Saif N. Al-Bahry; Abdul Qader Elshafie; Charles S. Bakheit
Abstract Green Turtle eggs were collected at random from 5 different nests from the Ras Al-Hadd Reserve in Oman. They were incubated 16hr after oviposition at constant temperatures set at 30–31°C for female producers and at 26–27° for male producers. Standard histological procedure of the gonads was performed for sex determination. Despite the constant temperatures set in the incubators, there were differences among the incubated eggs. This is similar to the natural condition, where an asynchronous pattern of emergence is common. Pipping occurs when the eggshell has a slit and hatching is when the head and one flipper are outside the eggshell. Emergence occurs when the hatchling is completely free from the extraembryonic membranes and eggshell. There was no correlation between the pipping-hatching and hatching-emergence intervals in the female, but in males the two intervals were significantly correlated (P<0.01). Hatchling weights were: 28.22 g (±0.83) for females and 25.74 g (±0.58) for males. In both sexes, hatchling weight did not influence the duration of the two intervals. The duration between pipping emergence was significantly (P<0.01) longer in females than in males. Natural and incubator observations showed that the hatchlings remained in the nest after emergence for at least 48hr until the umbilical swelling had subsided before attempting their emergence escape. While the hatchlings remain inside the eggshell after pipping attached to chorioallontoic/amniotic membranes, they are occasionally vulnerable to injury by nesting turtles, micro-organisms or early-emerged hatchlings inside the nest.
Environmental Modelling and Software | 2005
Sabah A. Abdul-Wahab; Charles S. Bakheit; Saleh M. Al-Alawi
Environmental Modelling and Software | 2008
Saleh M. Al-Alawi; Sabah A. Abdul-Wahab; Charles S. Bakheit
Marine Pollution Bulletin | 2007
Abdulkadir E. Elshafie; A.Y.A. AlKindi; Sultan Al-Busaidi; Charles S. Bakheit; Saif N. Al-Bahry
Sultan Qaboos University Medical Journal | 2006
Atsu S.S. Dorvlo; Charles S. Bakheit; Asya Al-Riyami; Magdi Morsi; Samir Al-Adawi