Levothyroxine Timing during Ramadan: A Randomized Clinical Trial.

Introduction: Hypothyroidism requires lifelong thyroid hormone replacement with levothyroxine. For most hypothyroid patients fasting during Ramadan, compliance with the administration procedure is a challenge. This study aimed to determine the impact of different administration times of levothyroxine on thyroid-stimulating hormone (TSH) and free T4 (FT4) levels before and after the holy month of Ramadan. Materials and Methodology. Hypothyroid patients taking levothyroxine were randomized to 3 groups during Ramadan: group 1, 30 minutes before the iftar meal; group 2, 3-4 hours after the iftar meal, with no food taken for at least 1 hour after the meal; group 3, they were not given specific instructions for taking levothyroxine during Ramadan. Thyroid function tests were performed within 2 weeks before Ramadan and within 2 weeks after Ramadan. Pre- and post-Ramadan TSH and free T4 levels were compared. Mixed-effects analyzes were performed to identify factors associated with changes in TSH and FT4 levels. Results: Compliance was lower in patients taking levothyroxine 3-4 hours after iftar. In addition, the majority of patients who had not received a specific recommendation took levothyroxine 30 minutes before iftar. There was a statistically significant increase in TSH (P=0.006) and FT4 (P=0.044) levels after Ramadan. In multivariate analysis, the cause of hypothyroidism (Hashimoto's; postthyroidectomy; compared to postradioactive iodine) and levothyroxine dose significantly affected FT4 levels. In contrast, no variable was significantly associated with TSH level. The timing of levothyroxine intake during Ramadan did not significantly affect TSH or FT4 levels. Conclusion: TSH and FT4 significantly increased after Ramadan. However, the timing of levothyroxine intake per se had no influence on TSH or free T4 levels. Therefore, hypothyroid patients might take levothyroxine either 30 minutes or 3-4 hours after iftar with no meal for 1 hour, depending on preference.

The association between plasma homocysteine level and metabolic syndrome. A record-based study of Saudi patients attending King Abdulaziz Medical City in Riyadh, Saudi Arabia.

OBJECTIVES: To investigate the association between plasma homocysteine (Hcy) status and metabolic syndrome (MS) among Saudi patients attending King Abdulaziz Medical City in Riyadh, Saudi Arabia. METHODS: A record-based cross-sectional study of 446 patients was carried out. All consecutive plasma Hcy levels from 2015 to 2018 were extracted. International Diabetes Federation criteria for MS were used to classify the patients. A multivariate regression model was developed to examine the associations between plasma Hcy and MS. RESULTS: The mean plasma Hcy level was 10.52 µmol/L, and 40% of the patients exhibited elevated Hcy status. Male patients had significantly elevated Hcy levels compared to female patients (p less than 0.001). In addition, plasma Hcy levels were significantly higher in patients diagnosed with diabetes (p=0.021) and hypertension (p less than 0.001). The prevalence of MS within the study population was 51%. Homocysteine levels were associated with the presence of MS independent of demographic, anthropometric and biochemical variables (odd ratio 1.018; 95% confidence intervals 1.011 -1.047).  Conclusion: Plasma Hcy levels were elevated in 40% of the MS patients. Homocysteine had weak association with the presence of MS. Additionally, it was associated with some of its components individually. This study has raised the importance of investigating the association between Hcy status and MS among a representative sample of Saudi population. Additionally, examining possible association and interaction between Hcy level and specific component of MS is suggested to be explored in future studies.

The Risk of Nosocomial Transmission of Rift Valley Fever.

In 2000, we investigated the Rift Valley fever (RVF) outbreak on the Arabian Peninsula-the first outside Africa-and the risk of nosocomial transmission. In a cross-sectional design, during the peak of the epidemic at its epicenter, we found four (0.6%) of 703 healthcare workers (HCWs) IgM seropositive but all with only community-associated exposures. Standard precautions are sufficient for HCWs exposed to known RVF patients, in contrast to other viral hemorrhagic fevers (VHF) such as Ebola virus disease (EVD) in which the route of transmission differs. Suspected VHF in which the etiology is uncertain should be initially managed with the most cautious infection control measures.

Activation and deactivation by temperature: behavior of Ph2PN(iPr)P(Ph)N(iPr)H in the presence of alkylaluminum compounds relevant to catalytic selective ethene trimerization.

Coordination, deprotonation, rearrangement, and cleavage of Ph(2)PN(iPr)P(Ph)N(iPr)H (1) by trialkylaluminum compounds R(3)Al (R=Me, Et) are reported that are relevant to the selective ethene trimerization system consisting of the ligand 1, CrCl(3)(THF)(3) and Et(3)Al that produces 1-hexene in more than 90% yield and highest purity. With increasing temperature and residence time first the formation of an adduct [Ph(2)PN(iPr)P(Ph)N(iPr)H][AlR(3)] (2), second the aluminum amide [Ph(2)PN(iPr)P(Ph)(AlR(3))N(iPr)][AlR(2)] (3) and third its rearrangement to the cyclic compound [N(iPr)P(Ph)P(Ph(2))N(iPr)][AlR(2)] (4) were observed. The cleavage of 3 by an excess of R(3)Al into an amidophosphane and an iminophosphane could be the reason for its rearrangement to complex 4, as well as to the cyclic dimer [R(2)AlN(iPr)P(Ph)(2)](2) (5). The chemistry of ligand 1 in the presence of alkylaluminum compounds gives hints on possible activation and deactivation mechanisms of 1 in trimerization catalysis.

Coordination chemistry of new selective ethylene trimerisation ligand Ph2PN(iPr)P(Ph)NH(R) (R = iPr, Et) and tests in catalysis.

The synthesis of [Ph(2)PN((i)Pr)P(Ph)NH(R)] (R = (i)Pr, Et) (1, 2) is described and the structure of 2 has been determined by single-crystal X-ray analysis. Compound 1 readily reacts with chromium(0), nickel(0), nickel(II), palladium(II), platinum(II) and iron(II) complexes to give four-membered rings (3-10) via P,P' coordination. The molecular structures of [Cr(CO)(4){Ph(2)PN((i)Pr)P(Ph)NH(R)-P,P'}] (R = (i)Pr, Et) (3, 4), [Cr(CO)(3)(NCCH(3)){Ph(2)PN((i)Pr)P(Ph)NH((i)Pr)-P,P'}] (5), [Ni{Ph(2)PN((i)Pr)P(Ph)NH((i)Pr)-P,P'}(2)] (6), cis-[MX(2){Ph(2)PN((i)Pr)P(Ph)NH((i)Pr)-P,P'}] (M = Ni, Pd, Pt; X = Cl or Br) (7, 8, 9) and trans-[Fe(NCCH(3))(2){Ph(2)PN((i)Pr)P(Ph)NH((i)Pr)-P,P'}(2)](BF(4))(2) (10) have been determined by X-ray diffraction. In the solid state, these complexes show tight phosphine bite angles in the range 67.89(2) degrees to 74.97(4) degrees and the central nitrogen atom adopts an almost planar (sp(2)) geometry. Complexes 3, 5, 6, 7 and 10 are tested for their catalytic activity in ethylene oligomerisation. Additionally, complex 10 is tested in hydrogenation of olefins.

Influence of process parameters on the reaction kinetics of the chromium-catalyzed trimerization of ethylene.

In this paper we report the results of an extensive experimental kinetic study carried out on the novel ethylene trimerization catalyst system, comprising the chromium source [CrCl(3)(thf)(3)] (thf=tetrahydrofuran), a Ph(2)P-N(iPr)-P(Ph)-N(iPr)H (PNPNH) ligand (Ph=phenyl, iPr=isopropyl), and triethylaluminum (AlEt(3)) as activator. It could be shown that the initial activity shows a first-order dependency on the ethylene concentration. Also, a first-order dependency was found for the catalyst concentration. The initial activity follows a typical Arrhenius behavior with an experimentally determined activation energy of 52.6 kJ mol(-1). At elevated temperatures (ca. 80 degrees C), a significant deactivation was observed, which can be tentatively traced back to a ligand rearrangement in the presence of AlEt(3). After a fast initial phase, a pronounced 'kink' in the ethylene-uptake curve is observed, followed by a slow, almost linear, further increase of the total ethylene consumption. The catalyst composition, in particular the ligand/chromium and the cocatalyst/chromium molar ratio, has a strong impact on the catalytic performance of the trimerization of ethylene.

An alternative mechanistic concept for homogeneous selective ethylene oligomerization of chromium-based catalysts: binuclear metallacycles as a reason for 1-octene selectivity?

An alternative concept for the selective catalytic formation of 1-octene from ethylene via dimeric catalytic centers is proposed. The selectivity of the tetramerization systems depends on the capability of ligands to form binuclear complexes that subsequently build up and couple two separate metallacyclopentanes to form 1-octene selectively. Comparison of existing catalytic processes, the ability of the bis(diarylphosphino)amine (PNP) ligand to bridge two metal centers, and the experimental background support the proposed binuclear mechanism for ethylene tetramerization.

P-[N-(Diphenyl-phospho-rothio-yl)iso-propyl-amino]-N-isopropyl-P-phenyl-thio-phosphinic amide.

The title compound, C(24)H(30)N(2)P(2)S(2), was obtained by the reaction of Ph(2)PN(iPr)P(Ph)N(iPr)H with elemental sulfur in tetra-hydro-furan. In the solid state, intra-molecular N-H⋯S hydrogen bonding influences the mol-ecular conformation; a P-N-P-N torsion angle of 2.28 (9)° is observed. The two phenyl rings attached to one P atom form a dihedral angle of 74.02 (4)°.

Ocular complications of Rift Valley fever outbreak in Saudi Arabia.

OBJECTIVE: To report ocular complications of Rift Valley fever (RVF) during its first reported outbreak in southwest Saudi Arabia in autumn 2000. DESIGN: Cross-sectional study of patients in a referral hospital. PARTICIPANTS: One hundred forty-three consecutive patients with confirmed RVF serologic test results and ocular lesions were enrolled in the study. METHODS: Hospitalized patients (n = 30) and outpatients (n = 113) with clinical symptoms consistent with RVF, positive RVF serologic test results, and ocular abnormalities were studied. Ophthalmologic examinations, including fundus photography and fluorescein angiography, were performed. Patients were followed up at regular intervals to determine the prognosis and outcome of identified ocular abnormalities. MAIN OUTCOME MEASURES: Visual acuity at initial presentation and course of anterior and posterior segment complications. RESULTS: Among 143 patients (78% males; mean age, 53.2 years), 212 eyes were affected, comprising 47 eyes in 30 inpatients and 165 eyes in 113 outpatients. The mean interval between the onset of RVF and visual symptoms ranged from 4 to 15 days (mean, 8.8 days). Macular or paramacular retinitis was identified in all the affected eyes (n = 212) at the time of initial assessment. Lesions included retinal hemorrhages (40%), vitreous reactions (26%), optic disc edema (15%), and retinal vasculitis (7%). Anterior uveitis was present in 31% of outpatients. Fluorescein angiography of the retinitis showed early hypofluorescence with late staining of retinal lesions and blood vessels. Initial visual acuity was less than 20/200 in 80% of eyes in the outpatient group; their vision improved, deteriorated, or remained the same in 13%, 15%, or 72%, respectively. Evaluation at the last follow-up showed macular (60%) or paramacular (9%) scarring, vascular occlusion (23%), and optic atrophy (20%) in the outpatient group. CONCLUSIONS: Rift Valley fever was associated with major ocular morbidity. Ocular manifestations of RVF occurred with a relatively higher frequency than reported up to now and were not limited to severe infections. Rift Valley fever affects the uvea and posterior chorioretinal area and is associated with permanent visual loss resulting from macular and paramacular scarring, vascular occlusion, and optic atrophy. The study demonstrated for the first time that transient nongranulomatous anterior uveitis is associated with RVF.

Pediatric gastrointestinal basidiobolomycosis.

Basidiobolomycosisis an unusual fungal infection that manifests in the skin and rarely involves other systems including the gastrointestinal tract. We retrospectively reviewed records of six pediatric patients (< or =14 years of age) diagnosed with gastrointestinal basidiobolomycosis from March 2000 to March 2002. Four patients came from the same region, suggesting environmental exposure. Basidiobolomycosis should be considered in the differential diagnosis in pediatric patients presenting with abdominal mass and eosinophilia.

Epidemic Rift Valley fever in Saudi Arabia: a clinical study of severe illness in humans.

We describe the clinical patterns and case-fatality rate associated with severe Rift Valley fever (RVF) in patients who were admitted to the Gizan regional referral hospital during an outbreak of RVF in Saudi Arabia from September through November 2000. A total of 165 consecutive patients (136 men and 29 women) were prospectively studied; all were identified according to a strict case definition, were confirmed to have RVF by serologic testing, and were treated according to a predetermined protocol. The major clinical characteristics of RVF included a high frequency of hepatocellular failure in 124 patients (75.2%), acute renal failure in 68 patients (41.2%), and hemorrhagic manifestations in 32 patients (19.4%). Sixteen patients had retinitis and 7 patients had meningoencephalitis as late complications in the course of the disease. A total of 56 patients (33.9%) died. Hepatorenal failure, shock, and severe anemia were major factors associated with patient death.