Publications by authors named "Muallem A"

: Osteoporotic hip fractures in cirrhotic subjects are associated with increased post-fracture mortality. Our aim was to identify unfavorable factors that were associated with increased post-fracture mortality. : We employed a retrospective evaluation of the short- and long-term prognosis of cirrhotic patients that were admitted with a hip fracture to our institution.

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Introduction: Clinical Practice Guidelines (CPGs) development and implementation in the Kingdom of Saudi Arabia are suboptimal. The Kingdom's Vision 2030 envisages a transformational change to achieve an effective, integrated, value-based ecosystem focused on patient health.

Objectives: This study aimed to develop a CPG appraisal tool that will support the realization of the Kingdom's Vision 2030 through the development of high-quality and highly implementable CPGs.

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This study aimed to explore the effects of the lockdown due to the coronavirus disease 2019 pandemic on the incidence and characteristics of hip fracture in older adults. Data from the three-month lockdown period and the corresponding period in the previous year were obtained from the computerized medical records of a large acute-care hospital. No significant differences were observed in the absolute and relative numbers of hip fractures.

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Loss of heterozygosity (LOH) on 18q predicts poor survival in head and neck squamous cell carcinomas (HNSCCs). Several putative tumor suppressor genes, such as DCC, DPC4/Smad4, and MADR2/Smad2, are mapped to 18q, but thus far, the important gene locus in HNSCC is not known. To identify possible gene loci on 18q, we performed LOH studies using tumor DNA from 57 HNSCC primary tumor cell lines and DNA isolated from fibroblasts or lymphoblastoid cells from the same patients.

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Cytogenetic and molecular deletion analyses of azoospermic and oligozoospermic males have suggested the existence of AZoospermia Factor(s) (AZF) residing in deletion intervals 5 and 6 of the human Y-chromosome and coinciding with three functional regions associated with spermatogenic failure. Nonpolymorphic microdeletions in AZF are associated with a broad spectrum of testicular phenotypes. Unfortunately, Sequence Tagged Sites (STSs) employed in screening protocols range broadly in number and mapsite and may be polymorphic.

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Background: Some infertile men with azoospermia or severe oligospermia have small deletions in regions of the Y chromosome. However, the frequency of such microdeletions among men with infertility in general is unknown. We sought to determine the prevalence of Y-chromosome microdeletions among infertile men and to correlate the clinical presentation of the men with specific deletions.

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Microdeletions linked to deletion intervals 5 and 6 of the Y chromosome have been associated with male factor infertility. Members from at least two gene families lie in the region containing azoospermia factor (AZF), namely YRRM and DAZ. With the advent of intracytoplasmic sperm injection (ICSI), it is possible for men with severe male factor infertility to produce a child.

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The photoproduction of hydrogen by 2-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU)-inhibited chloroplasts from ascorbate under anaerobic conditions was studied in the pH range 5.0 to 7.5 using methyl viologen (MV), N,N,N',N'-tetramethyl-P-phenylenediamine (TMPD), and excess hydrogenase from Desulfovibrio desulfuricans.

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Light induced modulated signal of oxygen uptake by isolated chloroplasts in the presence of methyl viologen, when Photosystem II activity was inhibited and in the absence of any electron donors, was detected by a modulated oxygen Pt electrode, polarized negatively. Evidence is brought to show that an electrochemical process which takes place on the surface of the negatively polarized Pt-cathode produces an intermediate which serves as an electron donor to Photosystem I. Atempts to identify this intermediate show that it may be very probably the superoxide radical generated by the electrochemical reduction of oxygen which continuously diffuses from the external circulating medium to the electrode.

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Intact isolated chloroplasts were shown to exhibit a characteristic three-phase pattern of development of oxygen evolution activity. The first phase, Phase I, appeared to be an equilibration phase in which the isolated chloroplasts adapted to the conditions on the electrode surface. It was characterised by a rapidly increasing rate of oxygen evolution accompanied by decreasing enhancement signals.

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