Mechanism of H+ dissociation-induced O-O bond formation via intramolecular coupling of vicinal hydroxo ligands on low-valent Ru(III) centers.

The understanding of O-O bond formation is of great importance for revealing the mechanism of water oxidation in photosynthesis and for developing efficient catalysts for water oxidation in artificial photosynthesis. The chemical oxidation of the RuII2(OH)(OH2) core with the vicinal OH and OH2 ligands was spectroscopically and theoretically investigated to provide a mechanistic insight into the O-O bond formation in the core. We demonstrate O-O bond formation at the low-valent RuIII2(OH) core with the vicinal OH ligands to form the RuII2(µ-OOH) core with a µ-OOH bridge. The O-O bond formation is induced by deprotonation of one of the OH ligands of RuIII2(OH)2 via intramolecular coupling of the OH and deprotonated O- ligands, conjugated with two-electron transfer from two RuIII centers to their ligands. The intersystem crossing between singlet and triple states of RuII2(µ-OOH) is easily switched by exchange of H+ between the µ-OOH bridge and the auxiliary backbone ligand.

Configurationally Nonselective Aquation of a Mononuclear Ru(II) Chloro Complex to Aquo Complex Isomers with Distinctive Aspects in Photoisomerization, Redox, and Catalytic Water Oxidation.

distal-[Ru(EtOtpy)(pynp)Cl]+ (d-EtO1Cl) (EtOtpy = 4'-ethoxy-2,2':6',2″-terpyridine, pynp = 2-(2-pyridyl)-1,8-naphthyridine), and distal/proximal-[Ru(EtOtpy)(pynp)OH2]2+ (d/p-EtO1H2O) complexes were newly synthesized to investigate the synergistic influence of the geometric configuration coupled with substituent introduction of an ethoxy (EtO) group on the physicochemical properties and reactions of the Ru(II) complexes. Configurationally nonselective aquation of d-EtO1Cl was uniquely observed to form d/p-EtO1H2O isomers in water, in contrast to configurationally selective aquation of distal-[Ru(tpy)(pynp)Cl]+ (d-1Cl, tpy = 2,2':6',2″-terpyridine) without the EtO group [Yamazaki, H. . J. Am. Chem. Soc. 2011, 133, 8846-8849].The kinetic profiles of the aquation reactions of d-EtO1Cl were well analyzed using a sequential reversible reaction model assuming the reversible interconversion between d/p-EtO1H2O isomers via d-EtO1Cl. The observed equilibrium constant (Kiso) of isomerization between p/d-EtO1H2O was calculated from the kinetic analysis as Kiso = 0.45, which is consistent with the final concentration ratio (1:0.43) of p/d-EtO1H2O generated in the aquation reaction of d-EtO1Cl. The irreversible photoisomerization from d-EtO1H2O to p-EtO1H2O was observed in water with an internal quantum yield (Φ) of 0.44% at 520 nm. Electrochemical measurements showed that d-EtO1H2O undergoes a 2-step oxidation reaction of 1H+-coupled 1e- processes of RuII-OH2/RuIII-OH and RuIII-OH/RuIV═O at pH 1.3-9.7, whereas p-EtO1H2O undergoes a 1-step oxidation reaction of a 2H+-coupled 2e- process of RuII-OH2/RuIV═O in the pH range of 1.8-11.5. Any redox potential of d/p-EtO1H2O isomers was decreased by the electro-donating EtO substitution, compared with distal/proximal-[Ru(tpy)(pynp)OH2]2+ (d/p-1H2O). The turnover frequency (kO2 = 1.7 × 10-2 s-1) of d-EtO1H2O for water oxidation catalysis is higher than that (3.5 × 10-4 s-1) of p-EtO1H2O by a factor of 48.6. The kO2 value (1.7 × 10-2 s-1) for d-EtO1H2O is 4.5-fold higher than those of d-1H2O (3.8 × 10-3 s-1). The higher kO2 value of d-EtO1H2O compared with d-1H2O could be explained by the fast oxidation rate from RuIV═O to RuV═O involved in the rate-determining step due to the electron-donating EtO group.

Distinctive Aspects in Aquation, Proton-Coupled Redox, and Photoisomerization Reactions between Geometric Isomers of Mononuclear Ruthenium Complexes with a Large-π-Conjugated Tetradentate Ligand.

Geometric isomers of mononuclear ruthenium(II) complexes, distal-/proximal-[Ru(tpy)(dpda)Cl]+ (d-/p-RuCl, tpy = 2,2':6',2″-terpyridine, dpda = 2,7-bis(2-pyridyl)-1,8-diazaanthracene), were newly synthesized to comprehensively investigate the geometric and electronic structures and distinctive aspects in various reactions between isomers. The ultraviolet (UV)-visible absorption spectra of d-/p-RuCl isomers show intense bands for metal-to-ligand charge transfer (MLCT) at close wavelengths of 576 and 573 nm, respectively. However, time-dependent density functional theory (TD-DFT) calculations suggest that the MLCT transition of d-RuCl involves mainly single transitions to the π* orbital of the dpda ligand in contrast to mixing of the π* orbitals of the dpda and tpy ligands for p-RuCl. The aquation reaction (1.5 × 10-3 s-1) of p-RuCl to yield proximal-[Ru(tpy)(dpda)(OH2)]2+ (p-RuH2O) is faster than that (5.3 × 10-6 s-1) of d-RuCl in D2O/CD3OD (4:1 v/v) by three orders of magnitude, which resulted from the longer Ru-Cl bond by 0.017 Å and the distorted angle (100.2(3)°) of Cl-Ru-N (a nitrogen of dpda, being on a tpy plane) due to the steric repulsion between Cl and dpda for p-RuCl. Electrochemical measurements showed that d-RuH2O undergoes a 2-step oxidation reaction of 1H+-coupled 1e- processes of RuII-OH2/RuIII-OH and RuIII-OH/RuIV═O at pH 1-9, whereas p-RuH2O undergoes a 1-step oxidation reaction of a 2H+-coupled 2e- process of RuII-OH2/RuIV═O in the pH range of pH 1-10. The irreversible photoisomerization from d-RuH2O to p-RuH2O was observed in aqueous solution with an internal quantum yield (Φ) of 5.4 × 10-3% at 520 nm, which is lower compared with Φ = 1.1-2.1% of mononuclear Ru(II) aquo complexes with similar bidentate ligands instead of dpda by three orders of magnitude. This is possibly ascribed to the faster nonradiative decay rate from the excited 3MLCT state to the ground state for d-RuH2O due to the lower π* level of dpda ligands according to the energy-gap law: the rate decreases exponentially with the increasing energy gap.

Critical Hammett Electron-Donating Ability of Substituent Groups for Efficient Water Oxidation Catalysis by Mononuclear Ruthenium Aquo Complexes.

[Ru(Rtpy)(bpy)(H2O)]2+ (1R; bpy = 2,2'-bipyridine, and Rtpy = 2,2':6',2″-terpyridine derivatives) complexes with a variety of 4'-substituent groups on Rtpy were synthesized and characterized to reveal the effects of substituents on their structures, physicochemical properties, and catalytic activities for water oxidation. The geometric structures of 1R are not considerably influenced by the electron-donating ability of the 4'-substituent groups on Rtpy. Similar multistep proton-coupled electron transfer reactions were observed for 1R, and the redox potentials for each oxidation step tended to decrease with an increase in the electron-donating ability of the substituent, which is explained by the increased electron density on the Ru center by electron-donating groups, stabilizing the positive charge that builds up upon oxidation. This is consistent with the red-shift of the absorption bands around 480 nm assigned to the metal-to-ligand charge transfer transition for 1R due to the increased d orbital energy level of the Ru center. The turnover frequency (kO2) of 1R for water oxidation catalysis, however, depended greatly on the Rtpy ligands, varying from 0.05 × 10-2 to 44 × 10-2 s-1 (as the highest kO2 was observed for R = ethoxy) by a factor of 880. A critical electron-donating ability of the 4'-substituent groups with a narrow range of Hammett constants (σp = -0.27 to -0.24) found for the highest kO2 values is valuable for understanding the great difficulty in the search for efficient water oxidation catalysts. On another front, the kO2 values increased with a decrease in the redox potentials of RuIV═O/RuV═O for 1R, indicating that the potential of formation of RuV═O species for 1R is crucial for water oxidation catalysis under the employed conditions.

Correction to: Comparative study using fractional carbon dioxide laser versus glycolic acid peel in treatment of pseudo-acanthosis nigricans.

Unfortunately, there are two mistakes in the published article. The first mistake is found in the Results section, Clinical improvement subsection. The last sentence "There was no statistical difference between both sides (P=0.008)." should be corrected to "There was statistical difference between both sides (P=0.008)."

Efficient Solar-Assisted O2 Reduction Using a Cofacial Iron Porphyrin Dimer Catalyst Integrated into a p-CuBi2 O4 Photocathode.

A cofacial iron porphyrin heterodimer, Fe2 TPFPP-TMP showed high electrocatalytic activity, selectivity, and stability for O2 reduction to H2 O both in homogeneous non-aqueous and heterogeneous neutral aqueous solutions. When it is integrated to FTO/p-CuBi2 O4 (FTO=fluorine doped tin oxide) photocathode prepared by a simple novel method, a remarkable efficient solar-assisted O2 reduction is achieved in neutral potassium phosphate (KPi) or basic NaOH solutions saturated with O2 .

Correction to: Comparative study using fractional carbon dioxide laser versus glycolic acid peel in treatment of pseudo-acanthosis nigricans.

The author found small mistakes in scientific content of article. Editor-in-Chief confirmed that mistakes do not change or invalidate conclusions of article.

Comparative study using fractional carbon dioxide laser versus glycolic acid peel in treatment of pseudo-acanthosis nigricans.

Pseudo-acanthosis nigricans is a common dermatological disorder that is usually difficult to treat secondary to maceration of the skin from excessive sweating, obesity, or associated with endocrine disorders. Fractional photothermolysis and chemical peeling have been reported to improve the condition. To determine whether fractional CO2 laser resurfacing or glycolic acid peel is more effective and safe option for therapy. Twenty Egyptian patients were included in the study where each patient was subjected to three sessions of both fractional CO2 on the right side of the neck and glycolic acid peel 70% on the left side of the neck. All patients were evaluated by a scoring system Acanthosis Nigricans Area and Severity Index (ANASI) score and three blinded dermatologists before and after treatment. Clinical improvement on the side treated by glycolic acid peel showed 43% improvement while the side treated by fractional CO2 showed 19% improvement. Glycolic acid peel shows superior results to fractional CO2 due to accelerated induced exfoliation, yet still fractional CO2 results are promising due to a presumably long-term improvement of skin texture.

Hospital outbreak of Middle East respiratory syndrome coronavirus.

BACKGROUND: In September 2012, the World Health Organization reported the first cases of pneumonia caused by the novel Middle East respiratory syndrome coronavirus (MERS-CoV). We describe a cluster of health care-acquired MERS-CoV infections. METHODS: Medical records were reviewed for clinical and demographic information and determination of potential contacts and exposures. Case patients and contacts were interviewed. The incubation period and serial interval (the time between the successive onset of symptoms in a chain of transmission) were estimated. Viral RNA was sequenced. RESULTS: Between April 1 and May 23, 2013, a total of 23 cases of MERS-CoV infection were reported in the eastern province of Saudi Arabia. Symptoms included fever in 20 patients (87%), cough in 20 (87%), shortness of breath in 11 (48%), and gastrointestinal symptoms in 8 (35%); 20 patients (87%) presented with abnormal chest radiographs. As of June 12, a total of 15 patients (65%) had died, 6 (26%) had recovered, and 2 (9%) remained hospitalized. The median incubation period was 5.2 days (95% confidence interval [CI], 1.9 to 14.7), and the serial interval was 7.6 days (95% CI, 2.5 to 23.1). A total of 21 of the 23 cases were acquired by person-to-person transmission in hemodialysis units, intensive care units, or in-patient units in three different health care facilities. Sequencing data from four isolates revealed a single monophyletic clade. Among 217 household contacts and more than 200 health care worker contacts whom we identified, MERS-CoV infection developed in 5 family members (3 with laboratory-confirmed cases) and in 2 health care workers (both with laboratory-confirmed cases). CONCLUSIONS: Person-to-person transmission of MERS-CoV can occur in health care settings and may be associated with considerable morbidity. Surveillance and infection-control measures are critical to a global public health response.

Quasiparticle interference, quasiparticle interactions, and the origin of the charge density wave in 2H-NbSe2.

We show that a small number of intentionally introduced defects can be used as a spectroscopic tool to amplify quasiparticle interference in 2H-NbSe2 that we measure by scanning tunneling spectroscopic imaging. We show, from the momentum and energy dependence of the quasiparticle interference, that Fermi surface nesting is inconsequential to charge density wave formation in 2H-NbSe2. We demonstrate that, by combining quasiparticle interference data with additional knowledge of the quasiparticle band structure from angle resolved photoemission measurements, one can extract the wave vector and energy dependence of the important electronic scattering processes thereby obtaining direct information both about the fermiology and the interactions. In 2H-NbSe2, we use this combination to confirm that the important near-Fermi-surface electronic physics is dominated by the coupling of the quasiparticles to soft mode phonons at a wave vector different from the charge density wave ordering wave vector.

Investigating the informed consent process, therapeutic misconception and motivations of Egyptian research participants: a qualitative pilot study.

Few studies have explored the informed consent process among research participants in developing countries. This study aimed to evaluate the informed consent process, therapeutic misconception and motivation for participation among Egyptians participating in clinical trials. In a cross-sectional qualitative pilot study 103 participants in 10 clinical trials responded to a questionnaire. Over 90% agreed they had time to ask questions and received adequate information about the risks prior to consenting. All participants thought the research and the drug would improve their condition; only 46.1% were aware of receiving a non-approved experimental drug and 21.3% of being randomized. Reasons for participation included: better treatment (100%), to benefit society & advance science (85.4%), to receive free drugs (42.6%) and medical care (43.6%), to get hospitalized (15.8%) and to receive money or gifts (4.9%). Investigators need to emphasize the distinction between research and clinical care to address the high rate of therapeutic misconception.

Risk factors of gestational diabetes mellitus in the refugee population in Gaza Strip: a case-control study.

To determine the risk factors of gestational diabetes mellitus in refugee populations in the Gaza Strip, a retrospective case-control study was performed between March and June 2011 in the United Nations Relief and Works Agency (UNRWA) primary health care clinics. Data were collected on maternal sociodemographics and the prevalence of diagnosed GDM according to World Health Organization criteria from clinics where postnatal Palestinian refugee women had been diagnosed with GDM during previous pregnancies, and non-GDM women were used as controls. Sociodemographic characteristics, pre-pregnancy body-mass index (BMI), obstetrics history and family history of diabetes were used as study variables. In total, 189 incident cases of GDM were identified. The most significant risk factors for GDM were: history of miscarriage more than once; overweight before pregnancy; history of stillbirth; history of caesarean birth; and positive family history of diabetes mellitus.

Association between human leukocyte antigen-DR and demylinating Guillain-Barre syndrome.

OBJECTIVE: To find an association between human leukocyte antigen (HLA) class II DRB1, DRB3, DRB4, and DRB5 alleles frequencies in a sample of Iraqi patients with Guillain-Barre syndrome (GBS) and compare with a healthy control group. METHODS: We performed a cross-sectional study consisting of 30 Iraqi Arab patients with GBS attending the Neurological Department in the Neuroscience Hospital, Baghdad, Iraq between September 2012 and June 2013. The control group comprised 42 apparently healthy volunteers. Human leukocyte antigen genotyping for HLA DRB1, DRB3, DRB4, and DRB5 was performed using the polymerase chain reaction-sequence-specific primers method. The allele frequencies were compared across both groups. Major histocompatibility complex (MHC)-class II HLA-DR genotyping and serotyping were performed by software analysis. RESULTS: We found increased frequencies of HLA genotype DRB1*03:01 (p=0.0009), DRB1*07:01 (p=0.0015), and DRB4*01:01 (p<0.0001) in patients with GBS compared with healthy controls. The HLA DR6 was increased in the control group (p<0.0001). CONCLUSION: Our results suggest an association between HLA-DRB1*03:01, DRB1*07:01, DRB4*01:01, and HLA DR3, DR7 and a susceptibility to GBS.

Temperature-Controlled Transformation of WO3 Nanowires into Active Facets-Exposed Hexagonal Prisms toward Efficient Visible-Light-Driven Water Oxidation.

A unique transformation of WO3 nanowires (NW-WO3) into hexagonal prisms (HP-WO3) was demonstrated by tuning the temperature of the (N2H4)WO3 precursor suspension prepared from tungstic acid and hydrazine as a structure-directing agent. The precursor preparation at 20 °C followed by calcination at 550 °C produced NW-WO3 nanocrystals (ca. <100 nm width, 3-5 µm length) with anisotropic growth of monoclinic WO3 crystals to (002) and (200) planes and a polycrystalline character with randomly oriented crystallites in the lateral face of nanowires. The precursor preparation at 45 °C followed by calcination at 550 °C produced HP-WO3 nanocrystals (ca. 500-1000 nm diameter) with preferentially exposed (002) and (020) facets on the top-flat and side-rectangle surfaces, respectively, of hexagonal prismatic WO3 nanocrystals with a single-crystalline character. The HP-WO3 electrode exhibited the superior photoelectrochemical (PEC) performance for visible-light-driven water oxidation to that for the NW-WO3 electrode; the incident photon-to-current conversion efficiency (IPCE) of 47% at 420 nm and 1.23 V vs RHE for HP-WO3 was 3.1-fold higher than 15% for the NW-WO3 electrode. PEC impedance data revealed that the bulk electron transport through the NW-WO3 layer with the unidirectional nanowire structure is more efficient than that through the HP-WO3 layer with the hexagonal prismatic structure. However, the water oxidation reaction at the surface for the HP-WO3 electrode is more efficient than the NW-WO3 electrode, contributing significantly to the superior PEC water oxidation performance observed for the HP-WO3 electrode. The efficient water oxidation reaction at the surface for the HP-WO3 electrode was explained by the high surface fraction of the active (002) facet with fewer grain boundaries and defects on the surface of HP-WO3 to suppress the electron-hole recombination at the surface.

in vivo Evaluation of Immunomodulatory Activity of Lipopolysaccharide Zinc Oxide Nanoparticles (LPS-ZnNPS).

Klebsiella pneumoniae causes a wide variety of infectious diseases. Lipopolysaccharide (LPS) is a large heat-stable polymer that is gram-negative bacteria's major outer membrane component, accounting for roughly 75% of the surface area and 5-10% of the total dry weight. Therefore the current in vivo study was carried out to investigate the immunomodulatory effect of purified lipopolysaccharide produced from local clinical Klebsiella pneumoniae isolates compared with ZnO-NPs and LPS-ZnO NPs. To do the experimental evaluations 35, Balb/c mouse was injected intramuscularly (i.m.) with different concentrations of the purified LPS, ZnoNPs and LPS-ZnoNPs for 12 days and immunized with 10% SRBCs (i.p) on day 4 and 8 of the schedule, while K. pneumoniae suspension and normal saline for positive and negative control groups. Focus on estimating body weight before and after treatment, Arthus and delayed-type hypersensitivity, and detecting serum level of cytokines (TLR-2, IL1Beta, IL4, and IL10) using sandwich ELISA. The data showed the highest value before and after treatment with LPS-ZnO NPs recorded in 2µg/mouse was 27. 92±1.48 and 31.50±0.4, respectively. In Arthurs reaction and Delayed type hypersensitivity, the highest results showed in the positive control group injected with K. pneumoniae 4.08±0.17 and 4.86±80.02, respectively. The results of TLR-2 showed the highest value in the positive control group, 242.17±3.98 pg/ml, followed by Group LPS at 135.51.58 pg/ml. The results of Interleukin-1Beta showed the highest value in the positive control group, 254.88±3.51 pg/ml, followed by Group LPS 174.3± 1.46 pg/ml. The concentration of IL-4 in serum of treated albino mice showed the highest value in the positive control group, 136.2±1.12 pg/ml, followed by Group LPS 86.12±1.49 pg/ml. While the highest value of IL-10 was recorded in the positive control group, 98.58± 4.09 pg/ml, followed by Group LPS- ZnoNP in concentration 4µg/ mouse was 86.018±0.69 pg/ml. The results of the statistical analysis showed a significant difference (P≤0.05) between LPS, ZnoNPs, and LPs-ZnoNPs treated groups and control groups (positive & negative). In the present study, we can conclude that LPS-ZnO NPs had a positive immunomodulatory effect on immune response in immunized mice. As shown in the results of the level of IL-1 beta, IL-4, IL-10, and TLRs-2, Abs titer, and Arthus and DTH reactions.

Highly Efficient and Durable Electrocatalysis by a Molecular Catalyst with Long Alkoxyl Chains Immobilized on a Carbon Electrode for Water Oxidation.

A dinuclear Ru complex, proximal,proximal-[Ru2L(C8Otpy)2(OH)(OH2)]3+ (C8Otpy = 4'-octyloxy-2,2'; 6',2″-terpyridine) (1) with long alkoxyl chains, was synthesized to be immobilized on a carbon paper (CP) electrode via hydrophobic interactions between the long alkoxyl chains and the CP surface. The 1/CP electrode demonstrated efficient electrocatalytic water oxidation with a low overpotential (ηonset) of 0.26 V (based on the onset potential for water oxidation) in an aqueous medium at pH 7.0, which is compared advantageously with those of hitherto-reported molecular anodes for water oxidation. The active species of RuIIIRuIII(µ-OO) with a µ-OO bridge was involved in water oxidation at 0.95 V versus Ag/AgCl. As the applied potential increased to 1.40 V, water oxidation was promoted by participation of the more active species of RuIIIRuIV(µ-OO), and very durable electrocatalysis was gained for more than 35 h without elution of 1 into the electrolyte solution. The introduced long alkoxyl chains act as a dual role of the linker of 1 on the CP surface and decrease the η value. Theoretical investigation provides insights into the O-O bond formation mechanism and the activity difference between RuIIIRuIII(µ-OO) and RuIIIRuIV(µ-OO) for electrocatalytic water oxidation.

Autologous melanocyte-keratinocyte suspension in the treatment of vitiligo.

BACKGROUND: In stable vitiligo, several techniques of autologous transplantation of melanocytes are used. Autologous melanocyte transplantation of non-cultured melanocytes is one of those techniques with variable reported outcomes. OBJECTIVE: The objective of this study was to evaluate the response to autologous melanocyte-keratinocytes suspension transplantation in cases of stable vitiligo. METHODS: A total of 25 cases of vitiligo were treated by autologous melanocyte-keratinocytes suspension transplantation. After 6-17 months, patients' response was evaluated according to the extent of pigmentation (excellent 90-100%, good 50-89%, fair 20-49% and poor response <20%). RESULTS: Of the 25 patients treated, 22 continued the follow-up period. Five (23%) patients showed excellent response, 7 (32%) good, 6 (27%) fair and 4(18%) showed poor response. CONCLUSION: Unlike transplantation of cultured melanocytes, which requires experience in culture technique, autologous melanocyte-keratinocytes suspension transplantation is an easy economic technique, which may be used in resistant areas of stable vitiligo.

Disability and prognosis of relapsing remitting multiple sclerosis, is it different in Iraqi patients?

OBJECTIVE: To assess the prognostic factors of relapsing remitting multiple sclerosis (RR-MS) in Iraqi patients. METHODS: This retrospective study of patients with RR-MS was carried out at the MS Clinic in Baghdad Teaching Hospital, Baghdad, Iraq between March 2008 and January 2010. Patients history and extended disability status scale scores were reviewed using the clinic database. RESULTS: Five hundred patients (270 female, and 230 male) fulfilled the McDonald criteria for RR-MS, their mean age was 45.58 years. Mono symptoms were found in 70% of patients. Hemiplegia (48%) was the most common clinical feature followed by optic neuritis (24%). Poor prognostic indicators were older age at onset, pyramidal and sphincter involvement at the beginning of the illness, and more relapses in the first 2 years of the illness. There were no significant effects of gender or symptom type as prognostic indicators on the residual disability of the studied patient. CONCLUSION: Older age at onset, pyramidal and sphincter involvement at the beginning of the illness, and more relapses in the first 2 years of the illness were poor prognostic indicators.

Clinical and radiological study of Iraqi multiple sclerosis patients with childhood onset.

OBJECTIVE: To study the clinical and radiological characteristics of multiple sclerosis (MS) with onset below 18 years. METHODS: This retrospective study was carried out at the MS Clinic in the Medical City Hospital in Baghdad, Iraq between March 2008 and March 2009. The records of the center were surveyed, and 77 patients with the onset of MS below 18 years were identified. Their clinical and radiological data were then analyzed. RESULTS: The female:male ratio was 1.6:1, and the mean age at onset was 14.95 years. Seven (9.1%) patients where children (age below 10 years), and 70 (90.9%) patients where adolescents (age 10-18 years) at onset. Seventy patients (90.9%) had an initial course of relapsing remitting MS, 9 (11.7% of the total) of them progressed to secondary progressive MS after a mean duration of 9.87+/-4.135 years. Seven patients had primary progressive MS as the initial course. The most common presenting symptom was optic neuritis (35.8%). Fifty-nine (76.6%) patients had monofocal presentation, and 18 (23.4%) had polyfocal presentation. Fifty-one (63%) patients had periventricular MRI lesions. The percentage of supratentorial lesions was higher than infratentorial lesions, children had a higher incidence of basal ganglionic lesions than adolescents (p=0.002), and males had a higher incidence of infratentorial lesion than females (p=0.033). CONCLUSION: Male patients have a higher incidence of infratentorial MRI lesions than female patients. Children had a higher incidence of MRI lesions in the basal ganglia than adolescents.

Intestinal protozoan infections among Egyptian neutropenic patients with acute leukemia.

Several enteric protozoan species are linked to diarrhea in humans, with some causing debilitating illnesses, essentially in immunocompromised and neutropenic patients as in acute leukemias. The aim of this study was to detect intestinal protozoa in Egyptian neutropenic patients with acute leukemia. The study comprised two groups; 40 newly diagnosed neutropenic acute leukemia patients and 30 controls. Stool samples were collected from all participants and subjected to routine microscopic examination, special staining and detection of copro-antigen using rapid diagnostic test (RDT) RIDA®QUICK Entamoeba/ Giardia/ Cryptosporidium Combi. Cases were tested post-chemotherapy at the nadir of neutropenia (absolute neutrophil count ANC<= 0.5x109/L) and 19 cases were also tested initially prior to chemotherapy. Of examined patients, 15/40 (37%) were positive for Blastocystis hominis by wet mount, 10/40 (25%) had microsporidia using modified trichrome stain and only 2 cases (5%) of Cryptosporidium spp. by Ziehl-Neelsen stain. By RDT, 8/40 cases (20%) were positive compared to entirely negative controls. The positive cases included 4 patients with G. intestinalis 2 with Entamoeba and 2 with Cryptosporidium.19/40 cases were tested both pre- and post-chemotherapy. microsporidian spp. was diagnosed in 6/19 cases at the nadir of neutropenia compared to none of the cases pre-chemotherapy and the difference was statistically significant (p= 0.031*). Intestinal protozoa in acute leukemia patients post-chemotherapy are common especially B. hominis. Furthermore, RDT might be helpful for diagnosing intestinal protozoa in acute leukemia. Attention is highly required as intestinal protozoa infection can emerge after chemotherapy such as microsporidia.