Sclerotherapy for hemorrhoidal disease: systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis aimed to evaluate the safety and efficacy of sclerotherapy methods for hemorrhoidal disease (HD) over the past 40 years.

METHODS

The review followed the 2020 Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. A comprehensive literature search was conducted, including studies reporting the use of sclerotherapy in patients with HD. Study eligibility criteria were defined, and data were extracted independently by the authors. Random-effects meta-analyses were performed to assess outcomes of interest.

RESULTS

Out of 1965 records identified, 44 studies met the inclusion criteria, involving 9729 patients. The majority of studies were conducted in Japan, followed by the UK, Italy, and Portugal. The median age of participants was 52 years, and the majority were male. The Goligher grade distribution indicated varying degrees of HD severity. Sclerotherapy was predominantly administered through anoscopy, with polidocanol being the most commonly used agent. The procedure was generally performed without pre-injection analgesia. The meta-analysis of 14 randomized controlled trials (RCTs) revealed that sclerotherapy was not inferior to control interventions in terms of success rate (risk ratio [RR] 1.00, 95% CI 0.71-1.41) and recurrence rate (RR 1.11, 95% CI 0.69-1.77), while resulting in fewer complications (RR 0.46, 95% CI 0.23-0.92).

CONCLUSIONS

This systematic review highlights the safety and efficacy of sclerotherapy for HD, which yields similar success rates and fewer complications compared to other conservative or surgical approaches. Further research is warranted to optimize sclerotherapy techniques and evaluate long-term outcomes.

REGISTRATION

PROSPERO 2023 CRD42023396910.

Influence of quercetin on amiodarone pharmacokinetics and biodistribution in rats

OBJECTIVE

Amiodarone (AMD), a drug of choice to treat cardiac arrhythmias, has a narrow therapeutic index (NTI). It inhibits CYP3A4, CYP2C9, and CYP2D6 enzymes. Quercetin (QUE), a pharmacologically important bioflavonoid in vegetables and fruits, is important in treating cardiovascular comorbidities. QUE alters the bioavailability of drugs used concurrently by dual inhibition of P-glycoproteins (P-gp) and cytochrome (CYP) enzyme systems. The current study aimed to investigate the pre-treatment and co-administration effect of QUE on AMD pharmacokinetics in rats.

MATERIALS AND METHODS

Two separate animal trials (I and II) were planned to probe the effect of QUE on AMD pharmacokinetics by following previously cited studies. The pre-treatment group received oral doses of QUE for 14 days, and a single dose of AMD on the 15th day. Rats were administered single doses of QUE (20 mg/kg) and AMD (50 mg/kg) concurrently in a carboxymethylcellulose (CMC) in the co-administration study. Blood was collected at pre-determined time points. AMD was quantified by HPLC, and data was analyzed by PK solver software.

RESULTS

In the pre-treated group, peak plasma concentration (Cmax) and area under the curve (AUC0-∞) of AMD were increased by 45.52% and 13.70%, respectively, while time to achieve maximum concentration (tmax), half-life (t1/2) and clearance (CL) were declined by 35.72%, 16.75%, and 11.0% respectively compared to the control. In the co-administered group, compared to controls, Cmax and AUC0-∞ were elevated to 12.90% and 7.80%, respectively, while tmax, t1/2, and CL declined by 16.70%, 2.35%, and 13.40%. Further, AMD was increased in lung tissue of both treated groups, relative to the respective controls.

CONCLUSIONS

A notable pharmacokinetic drug interaction between QUE and AMD was observed in rats and warrants possible drug interaction study in humans, suggesting AMD dose adjustment specifically in patients with arrhythmia having a pre-treatment history and simultaneous administration of QUE-containing products.

Scrutinizing the therapeutic response of Phyllanthus exmblica's different doses to restore the immunomodulation potential in immunosuppressed female albino rats

OBJECTIVE

Immunosuppression and microbial resistance are the major drawbacks in conventional pharmaceutics. The present research work was planned to screen and characterize phytochemical constituents present in Phyllanthus emblica and to explore the immunomodulation potential of P. emblica by evaluating stress markers and different biochemical parameters in animals.

MATERIALS AND METHODS

The phytochemical analysis explored the presence of antioxidant profiles and revealed the radical scavenging activities. In the second phase, an animal trial was performed using female albino rats. Female rats (n=18) were administered three different doses of P. emblica (low dose 100 mg/kg, intermediate 200 mg/kg, and high dose 300 mg/kg) for three weeks. After a significant change (p<0.05) in antioxidant status i.e., TOS and TAS, hematological, biochemical parameters, and immunoregulation i.e., IgM and IgG were elevated. Statistical analysis (ANOVA) illustrates that these selected plants have a great impact on microbial resistance and immunosuppression and have shown highly significant results.

RESULTS

The results of all in vitro and in vivo assays conducted as part of the recent research work offer considerable evidence that the chosen medicinal plant has the ability to induce specific hormone release and boost the immune system.

CONCLUSIONS

Based on our findings, it is proposed that medicinal herbs may be isolated using cutting-edge approaches to tackle the issues of immunosuppression and microbial resistance.

Determining the 3-substituted Coumarins inhibitory potential against the HslV protease of E. coli

OBJECTIVE

The growing bacterial resistance towards classical antibiotics demands the development of novel approaches for the effective treatment of potentially fatal bacterial infections in humans. Proteostasis is crucial for the survival of every living cell, as several important physiological functions depend on well-regulated proteostasis. Within bacteria, the regulation of proteostasis relies on AAA+ (Adenosine 5'-triphosphatases associated with diverse cellular activities), ATPases, such as the HslVU complex (heat shock locus gene products U and V), along with other proteases. The HslVU protease/chaperon complex is thought to be the progenitor of the eukaryotic proteasome that regulates proteostasis mostly in prokaryotes. This study aimed to determine the inhibitory potential of 3-substituted coumarin derivatives against Escherichia coli heat shock locus V (HslV) protease.

MATERIALS AND METHODS

In this study, twenty-three derivatives of 3-substituted coumarin were assessed for their inhibitory potential against E. coli HslV protease using both in-vitro and in-silico techniques.

RESULTS

Among all the tested compounds, US-I-64, US-I-66, US-I-67, and US-I-68 displayed notable inhibitory potential against the HslV protease, showing IC50 (half maximal inhibitory concentration) values ranging from 0.2 to 0.73 μM. Additionally, the inhibitory potential of these compounds against the eukaryotic proteasome was also evaluated using a separate in-silico study. It was found that these compounds did not bind with the proteasomal active site, suggesting no apparent side effects of these lead molecules.

CONCLUSIONS

These identified HslV protease inhibitors can be used for the development of novel and safer anti-bacterial drugs.

Halogens engineering-based design of agonists for boosting expression of frataxin protein in Friedreich's ataxia

OBJECTIVE

Decreased expression of the mitochondrial protein frataxin is the cause of the neurodegenerative disorder Friedreich's ataxia. In patients with cardiac disorders, the death rate of this disease is very high, up to 66%. In order to combat Friedreich ataxia, which is a potentially toxic disorder, de novo drug discovery and design have been created utilizing the approach of compound engineering with halogens. This study aimed to investigate the potential for effective treatment of Friedreich ataxia.

MATERIALS AND METHODS

The screening of twenty different agonist compounds was carried out in order to find the most promising agonist compound that may be used for molecular docking prediction against the Frataxin Protein. The compound with the lowest binding energies is then optimized by halogens. The final candidate's drug-like properties are identified through Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) profiling. Lipinski's rule of five was checked. Molecular dynamic stimulations were evaluated.

RESULTS

The most potent agonist compound was identified out of twenty different compounds utilizing a docking approach against the Frataxin Protein. The compound with the lowest binding energies was next subjected to optimization by halogens. The optimized agonist 9-[1-[(1S, 5R)-8, 8-dimethyl-8-azoniabicyclo[3.2.1]octan-3-yl]triazol-4-yl]fluoren-9-ol  has higher binding energy of -10.4Kcal/mol with molecular weight of 705.63 g/mol. Drug-like properties are identified through ADMET profiling, having water solubility of about -7.59, skin permeation -7.08 cm/s, bioavailability score 0.17, and high GI absorption. The candidate fulfills the Lipinski rule of five and portrays efficient molecular dynamic stimulations.

CONCLUSIONS

The selected agonist is one of the most potent compounds in increasing Frataxin protein expression. Furthermore, optimization with halogens can be a productive approach to improve the candidate's drug efficacy. The development of effective medications for the treatment of Friedreich ataxia would be aided by the results of these computational investigations.

Side chain inset of neurogenerative amino acids to metalloproteins: a therapeutic signature for huntingtin protein in Huntington's disease

OBJECTIVE

Huntington's disease is a dominant autosomal inherited neurodegenerative disease that results in progressive impairment, characterized by dementia, chorea, and behavioral and cognitive decline. The objective of this study was to investigate the potential activity of metalloproteins against the huntingtin protein using various insertion-based engineering computational methods. Metalloproteins, metal protein complexes involved in important biochemical and physiological processes, were explored as potential drug candidates for Huntington's disease.

MATERIALS AND METHODS

A total of 18 metalloproteins were selected as drug candidates and studied to assess their potential inhibitory effects on the huntingtin protein. The screening process was based on the lowest binding energy. The metalloprotein with the lowest docking score was chosen for side chain insertion of neurogenerative amino acids. The engineered metalloprotein was then evaluated based on physiochemical properties, allergenicity, toxicity, and surface accessibility. Cloning and expression analysis was performed to further investigate its potential as a therapeutic agent.

RESULTS

The metalloprotein chosen for side chain insertion, cytochrome C oxidase, showed promising results. It was computed as a probable non-allergen and exhibited no toxic domains, indicating its non-toxic nature. Additionally, it demonstrated a strong binding affinity with the huntingtin protein, with a binding energy of -1,253.3 Kcal/mol.

CONCLUSIONS

Metal-based proteins, when engineered with additional neurogenerative amino acids, hold potential as drug candidates for treating neurodegenerative diseases such as Huntington's disease. The successful development of these engineered metalloproteins could offer therapeutic advantages. Further testing, both in vitro and in vivo, is necessary to evaluate their efficacy and validate their potential activity as novel drugs for the treatment of neurodegenerative diseases.

A one-health approach to design an mRNA-based vaccine candidate against the lumpy skin disease virus as an alternative to live-attenuated vaccines

OBJECTIVE

Recently, lumpy skin disease (LSD) has been spread over the Asian, European, and Middle Eastern regions making it a significant hazard to the chain of cattle production, milk production, and human milk consumption, requiring prompt attention. Lumpy skin disease virus has high morbidity and low fatality rates, but its infections have led to terrible economic and agricultural consequences. Although live-attenuated vaccines have been commercialized, farmers in different regions have not taken them well because of the allergic responses against the vaccines. The study aims to develop an mRNA-based vaccine candidate for LSDV, using immunoinformatic approaches to minimize allergenicity and homology while maximizing immunogenic potential.

MATERIALS AND METHODS

The study used extensive immunoinformatic approaches to shortlist five proteins from the LSDV genome that belong to the transmembrane region and are crucial in early viral interaction with host cells. The B-cell and T-cell-specific epitopes were chosen based on non-allergenicity, antigenicity, non-homology, surface accessibility, and lower IC50 inhibition values. The construct's stability, hydrophilicity, and antigenic potential were analyzed using the instability index, Grand Average of Hydropathicity (GRAVY) index, and antigenicity, respectively.

RESULTS

We selected a total of 34 epitopes, consisting of 12 B-cell-specific epitopes and 22 T-cell-specific epitopes. These epitopes were chosen based on their characteristics such as non-allergenicity, antigenicity, non-homology, surface accessibility, and lower IC50 inhibition values. Specifically, 11 epitopes were selected for Major Histocompatibility Complex-I, and another 11 epitopes were chosen for Major Histocompatibility Complex-II. The inclusion of the RS09 adjuvant enhanced the immunogenic potential of the vaccine. The instability index was found to be 38.60. Additionally, the GRAVY index, indicating hydrophilicity, was calculated as -0.151. Furthermore, the antigenicity value of 0.6073 confirmed its potential to elicit an immune response. Further supporting its immunogenic potential, strong immune stimulation was observed, with IgM+IgG titers reaching 6,000 (arbitrary units) and IFNg titers measuring 400,000 ng/mL. These results provide additional evidence of the vaccine's ability to stimulate a robust immune response.

CONCLUSIONS

The study results indicate that the developed mRNA-based vaccine candidate for LSDV has high immunogenic potential and could serve as an effective alternative to live-attenuated vaccines. Further experimental validations are required to test its efficacy. The study also highlights the potential of the One-Health approach to tackle non-zoonotic diseases that have significant consequences for the environment and humanity.

Revolutionizing treatment for toxic shock syndrome with engineered super chromones to combat antibiotic-resistant Staphylococcus aureus

OBJECTIVE

Staphylococcus aureus-induced toxic shock syndrome (TSS) is a rare, but potentially fatal disease with limited treatment options. The emergence of antibiotic-resistant strains has led to a pressing need for the development of effective therapies. This study aimed to identify and optimize potential drug candidates against toxic shock syndrome by targeting the pathogenic toxin protein using chromones as lead compounds.

MATERIALS AND METHODS

In this study, 20 chromones were screened for their ability to bind to the target protein. The top compounds were further optimized through the addition of cycloheptane and amide groups, and the resulting compounds were evaluated for their drug-like properties using chemical absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiling.

RESULTS

Among the compounds screened, 7-Glucosyloxy-5-hydroxy-2-[2-(4-hydroxyphenyl) ethyl] chromone exhibited the highest binding affinity with a molecular weight of 341.40 g/mol and a binding energy of -10.0 kcal/mol. The optimized compound exhibited favorable drug-like properties, including high water solubility, synthetic accessibility, skin permeation, bioavailability, and gastrointestinal absorption.

CONCLUSIONS

This study suggests that chromones can be engineered to develop effective drugs against TSS caused by S. aureus. The optimized compound has the potential to be a promising therapeutic agent for the treatment of TSS, providing new hope for patients suffering from this life-threatening disease of toxic shock syndrome.

A pharmacophore screening approach of homeopathic phenols for a renovated design of fragment-optimized Bauhiniastatin-1 as a drug against acromegaly

OBJECTIVE

Acromegaly is a fatal and chronic disease that is caused by the abnormal secretion of growth hormone (GH) by the pituitary adenoma or pituitary tumor, resulting in an increased circulated concentration of insulin-like growth factors 1 (IGF-1), where in most of the cases it is secreted by a pituitary tumor. Higher levels of GH cause an increase in IGF-1 in the liver leading to multiple conditions such as cardiovascular diseases, glucose imbalance, cancer, and sleep apnea. Medical treatments such as surgery and radiotherapy can be used as the first choice of patients; however, specified human growth hormone control should be an essential treatment strategy due to an incidence rate of 0.2-1.1 yearly. Therefore, the main focus of this study is to develop a novel drug for treating acromegaly by exploiting medicinal plants that have been screened using phenol as a pharmacophore model to identify target therapeutic medicinal plant phenols.

MATERIALS AND METHODS

The screening identified thirty-four pharmacophore matches of medicinal plant phenols. These were selected as suitable ligands and were docked against the growth hormone receptor to calculate their binding affinity. The candidate with the highest screened score was fragment-optimized and subjected to absorption, distribution, metabolism, and excretion (ADME) analysis, in-depth toxicity predictions, interpretation of Lipinski's rule, and molecular dynamic simulations to check the behavior of the growth hormone with the fragment-optimized candidate.

RESULTS

The highest docking energy was calculated as -6.5 K/mol for Bauhiniastatin-1. Enhancing the performance of Bauhiniastatin-1 against the growth hormone receptor with fragment optimization portrayed that human growth hormone inhibition can be executed in a more efficient and better way. Fragment-optimized Bauhiniastatin-1 (FOB) was predicted with high gastrointestinal absorption, a water solubility of -2.61 as soluble, and synthetic accessibility of 4.50, achieving Lipinski's rule of 5, with low organ toxicity prediction and interpreting a positive behavior against the targeted protein. The discovery of a de novo drug candidate was confirmed by the docking of fragment-optimized Bauhiniastatin-1 (FOB), which had an energy of -4,070 Kcal/mol.

CONCLUSIONS

Although successful and completely harmless, present healthcare treatment does not always eradicate the disease in some individuals. Therefore, novel formulas or combinations of currently marketed medications and emergent phytochemicals will provide new possibilities for these instances.

Misconceptions about multiple sclerosis and pregnancy in the Qassim region in 2021-2022: a cross-sectional study

OBJECTIVE

Multiple sclerosis (MS) is a disease with higher female prevalence, and the majority of patients are of childbearing age. Thus, pregnancy concerns are important for patients with MS and their families. Improving the understanding of the effects of pregnancy on the progress of MS could improve the knowledge about pregnancy-related issues in MS patients. The aim of this study is to evaluate the general knowledge of Saudi adults living in the Qassim region regarding pregnancy-related relapses in relapsing-remitting MS (RRMS) and to identify misconceptions regarding pregnancy, breastfeeding, and the use of oral hormonal contraceptives among female MS patients.

SUBJECTS AND METHODS

A representative random cluster sample of 337 participants was used in this cross-sectional study. All participants were living in one of the following cities in the Qassim region: Buraydah, Unaizah, and Alrrass. Data collection was done between February 2022 and March 2022 using a self-administered questionnaire.

RESULTS

The overall mean knowledge score was 7.42 (SD 4.21), with poor, moderate, and good knowledge representing 77.2%, 187%, and 4.2% of the sample, respectively. Higher knowledge scores were associated with age less than 40 years, being a student, knowing about MS, and knowing someone with MS. Other variables such as gender, educational level, and residence location did not show significant differences regarding the knowledge score.

CONCLUSIONS

Our results demonstrate that knowledge and attitude are suboptimal among the Qassim population regarding the effects of MS on pregnant patients, pregnancy outcomes, breastfeeding, and usage of contraceptive methods, with 77.2% showing poor total knowledge scores.

The correlation between copy number variation in Chromosome 14 and DNA methylation in Saudi autistic children

OBJECTIVE

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that represents a range of aberrant behaviour symptoms such as repetitive behaviours and defects in social communication. The prevalence of ASD has been increasing worldwide and many studies have reported that both genetic and epigenetic factors play an important role in the etiology of this disorder. The aim of this study was to investigate the implementation of DNA methylation and Copy number variation (CNV) in the diagnosis of ASD.

PATIENTS AND METHODS

This study was carried out on 14 Saudi autistic children and four of their healthy siblings. Comparative genomic hybridization array was used to identify CNV in chromosome 14 and MethyLight qPCR was used to estimate levels of DNA methylation.

RESULTS

The results identified CNVs in six cytobands in chromosome 14 for 13 out of 14 autistic samples: 14q11.1-q11.2, 14q11.2, 14q12, 14q21.1, 14q32.2, and 14q32.33. However, some of these cytobands were also found in normal samples with different sizes. Interestingly, chromosomal abnormalities in 14q11.1-q11.2 was only found in ASD samples. The result also showed an increase in methylation ratio of ASD samples in those CNV regions compared with their siblings.

CONCLUSIONS

The findings suggest that CNV in 14q11.1-q11.2 might be a potential target in ASD diagnosis and further work is required to detect which biological pathways are affected.

Problematic smartphone usage and quality of life among Saudi adults

OBJECTIVE

Problematic use of and/or addiction to smartphones is a cause of concern for sociologists, psychologists, and health professionals. We aimed to assess the correlation between smartphone use and perceived quality of life.

SUBJECTS AND METHODS

We conducted a sample survey of university students and the general public that visited health facilities in the Qassim region of Saudi Arabia. We used previously developed and validated questionnaires to elicit information on the extent and pattern of smartphone use and perceived quality of life. We conducted analysis of variance and binary logistic regression to evaluate the correlation between smartphone use and perceived quality of life.

RESULTS

About 73% of participants were university students aged 18 to 24 years; there were slightly more women than men. The mean quality of life scores for physical and psychological health was significantly lower among women, singles, students, and those 18 to 24 years old. Perceived quality of physical and psychological health was significantly lower among users of applications for music and movies than users of religious applications. Participants with the lowest level of perceived quality of physical and psychological health were between 2.5 and 2.7 times more likely to have the highest level of problematic smartphone use.

CONCLUSIONS

We found that problematic smartphone use was strongly associated with perceived quality of life in the Qassim region of Saudi Arabia. We recommend awareness campaigns to reduce problematic smartphone use, particularly among the younger population and physician training on the diagnosis and management of problematic smartphone use/addiction.

Dorsal median lipectomy (the arrow technique): A new approach for the treatment of the circumferential truncal skin and fatty tissue excess

The increase in the number of patients who undergo massive weight loss surgery has led to an increasing number of patients who complain of circumferential abdominal skin and soft tissue excess. Currently, the only surgical option to treat soft tissue excess is vertical median abdominal lipectomy (fleur-de-lys technique). However, many patients are reluctant to undergo this surgery because of the position of the scar. We presented a new surgical approach to manage circumferential excess - dorsal median lipectomy (arrow technique) - in which the dorsal scar is well-tolerated by patients.

[Algorithm for surgical treatment of limb lymphedema]

Whether primary or secondary, limb lymphedema is a relatively common disease whose impact on the quality of life of patients is important. Although the microsurgical reconstruction techniques seem to be the techniques of choice in the treatment of limb lymphedema, no consensus about treatment of limb lymphedema has yet been defined. Considering the advantages and disadvantages of surgical techniques and their impact on the quality of life of patients, we propose a surgical treatment algorithm of limb lymphedema.

Raman gas self-organizing into deep nano-trap lattice

Trapping or cooling molecules has rallied a long-standing effort for its impact in exploring new frontiers in physics and in finding new phase of matter for quantum technologies. Here we demonstrate a system for light-trapping molecules and stimulated Raman scattering based on optically self-nanostructured molecular hydrogen in hollow-core photonic crystal fibre. A lattice is formed by a periodic and ultra-deep potential caused by a spatially modulated Raman saturation, where Raman-active molecules are strongly localized in a one-dimensional array of nanometre-wide sections. Only these trapped molecules participate in stimulated Raman scattering, generating high-power forward and backward Stokes continuous-wave laser radiation in the Lamb-Dicke regime with sub-Doppler emission spectrum. The spectrum exhibits a central line with a sub-recoil linewidth as low as ∼14 kHz, more than five orders of magnitude narrower than conventional-Raman pressure-broadened linewidth, and sidebands comprising Mollow triplet, motional sidebands and four-wave mixing.

Comparisons in childhood obesity and cardiometabolic risk factors among urban Saudi Arab adolescents in 2008 and 2013

BACKGROUND

We aimed to compare the prevalence of childhood obesity and other cardiometabolic risk factors from two independent cohorts (2008 and 2013) in Riyadh, Saudi Arabia.

METHODS

A total of 4549 adolescents aged 12-18 years [2454 boys, 2095 girls], taken from two independent cohorts, 5 years apart (2008 and 2013), were included. Anthropometrics were measured, and fasting blood samples were taken to ascertain glucose and lipid profile.

RESULTS

The overall prevalence of obesity was significantly higher in 2013 [15.3 (95% confidence interval 13.7-16.9)] than 2008 [12.6 (11.3-13.9)] (P = 0.012). Stratified by sex, the prevalence of obesity among boys was significantly higher in 2013 than 2008 [2008 = 12.0 (10.3-13.7) versus 2013 = 17.4 (15.1-19.7); P < 0.001]. The age groups 13 and 15 years had a significantly higher mean triglycerides in 2013 than 2008 (P-values 0.003 and <0.001, respectively) and lower mean HDL-cholesterol also in the 13 years old age group (P < 0.001).

CONCLUSIONS

The prevalence of childhood obesity in Saudi Arabia has increased in particular age groups (13-15 years) during a 5-year span. Special attention is warranted in these vulnerable age groups, particularly in boys, as cardiometabolic risk factors appear to worsen.

Cholecystokinin-1 receptor antagonists: 5-hydroxy-5-aryl-pyrrol-2-ones as anticancer agents

Hydroxy-pyrrolones, which were potent CCK1R antagonists, showed nanomolar in vitro activity and anticancer activity in vivo for colon and pancreatic cancer.

CW hollow-core optically pumped I₂ fiber gas laser

Continuous wave lasing of a hollow-core fiber gas laser (HOFGLAS) is achieved with molecular iodine in the 1280-1340 nm region when optically pumped at 532 nm.

Ultra low-loss hypocycloid-core Kagome hollow-core photonic crystal fiber for green spectral-range applications

We report on the development of a hypocycloidal-core Kagome hollow-core photonic crystal fiber guiding, with low transmission loss in the 450-650 nm visible spectral range. Transmission loss records have been achieved with 70  dB/km at 600 nm, and 130  dB/km at 532 nm. As a demonstration of the fiber potential applications, we report on a compact 600 THz wide Raman comb generator, centered around 532 nm, and on a 10 W average power frequency-doubled Yb-fiber picosecond laser beam delivery, along with its use for organic material laser micro-processing.

Multi-meter fiber-delivery and pulse self-compression of milli-Joule femtosecond laser and fiber-aided laser-micromachining

We report on damage-free fiber-guidance of milli-Joule energy-level and 600-femtosecond laser pulses into hypocycloid core-contour Kagome hollow-core photonic crystal fibers. Up to 10 meter-long fibers were used to successfully deliver Yb-laser pulses in robustly single-mode fashion. Different pulse propagation regimes were demonstrated by simply changing the fiber dispersion and gas. Self-compression to ~50 fs, and intensity-level nearing petawatt/cm(2) were achieved. Finally, free focusing-optics laser-micromachining was also demonstrated on different materials.

Hypocycloid-shaped hollow-core photonic crystal fiber Part I: arc curvature effect on confinement loss

We report on numerical and experimental studies showing the influence of arc curvature on the confinement loss in hypocycloid-core Kagome hollow-core photonic crystal fiber. The results prove that with such a design the optical performances are strongly driven by the contour negative curvature of the core-cladding interface. They show that the increase in arc curvature results in a strong decrease in both the confinement loss and the optical power overlap between the core mode and the silica core-surround, including a modal content approaching true single-mode guidance. Fibers with enhanced negative curvature were then fabricated with a record loss-level of 17 dB/km at 1064 nm.

Hypocycloid-shaped hollow-core photonic crystal fiber Part II: cladding effect on confinement and bend loss

We report on numerical and experimental studies on the influence of cladding ring-number on the confinement and bend loss in hypocycloid-shaped Kagome hollow core photonic crystal fiber. The results show that beyond the second ring, the ring number has a minor effect on confinement loss whereas the bend loss is strongly reduced with the ring-number increase. Finally, the results show that the increase in the cladding ring-number improves the modal content of the fiber.

Management of the perineal wound after abdominoperineal resection

Although many options are available for the management of perineal wounds after abdominoperineal resection, ranging from direct closure to flap reconstruction, treatment remains challenging. A better understanding of the aims, drawbacks and progress in perineal wound management after abdominoperineal rectal resection can help the surgeon make better choices for each patient, but it is very difficult to propose a single, optimal, evidence-based procedure for the management of pelvic exenteration. Recent progress provided by the extralevator abdominoperineal resection technique and perforator flap concepts have changed our conception of reconstruction leading to the different technical options highlighted in this review.

Design and fabrication of hollow-core photonic crystal fibers for high-power ultrashort pulse transportation and pulse compression

We report on the recent design and fabrication of kagome-type hollow-core photonic crystal fibers for the purpose of high-power ultrashort pulse transportation. The fabricated seven-cell three-ring hypocycloid-shaped large core fiber exhibits an up-to-date lowest attenuation (among all kagome fibers) of 40 dB/km over a broadband transmission centered at 1500 nm. We show that the large core size, low attenuation, broadband transmission, single-mode guidance, and low dispersion make it an ideal host for high-power laser beam transportation. By filling the fiber with helium gas, a 74 μJ, 850 fs, and 40 kHz repetition rate ultrashort pulse at 1550 nm has been faithfully delivered at the fiber output with little propagation pulse distortion. Compression of a 105 μJ laser pulse from 850 fs down to 300 fs has been achieved by operating the fiber in ambient air.

Millijoule laser pulse delivery for spark ignition through kagome hollow-core fiber

We report on power handling oriented design of kagome lattice hollow-core fiber and demonstrate through it for the first time nanosecond laser pulses induced spark ignition in a friendly manner. Two different core designs and transmission bands are investigated and evaluated. The energy threshold damage was measured to be in excess of the 10 mJ level and the output power density is approaching the TW/cm2 after focusing; demonstrating the outstanding ability of such fiber for high power delivery.

Pamidronate treatment of children with moderate-to-severe osteogenesis imperfecta: a note of caution

BACKGROUND/AIMS

Bisphosphonates have been reported to decrease fractures related to osteogenesis imperfecta (OI). We assessed the efficacy and long-term safety of pamidronate therapy in patients with moderate-to-severe OI.

METHODS

We conducted an open-label uncontrolled study in 14 boys and 13 girls whose mean age was 6.8 years at baseline. Intravenous pamidronate, 1 mg/kg/day, was given for 3 consecutive days every 4 months for 2-6 years, with physical therapy and orthopedic surgery as appropriate. Mobility score, fracture rate, height, bone mineral density (BMD) and bone healing were evaluated throughout follow-up.

RESULTS

In 24 (89%) patients, the fracture rate decreased to <or=2/year and/or the mobility score improved. The remaining 3 (11%) patients continued to experience more than 2 fractures per year with mobility scores <2 despite significant BMD gains. Delayed radiographic fracture healing (>6 months) occurred in 8 (29.6%) patients; their BMD gains, baseline age and treatment duration were not significantly different from those in the other patients. Tolerance was good.

CONCLUSION

Pamidronate with physiotherapy and orthopedic management improved outcomes without delaying fracture healing in 19 (70%) of 27 patients. Delayed fracture healing occurred in 8/27 patients. Pamidronate should be reserved for severe OI with multiple fractures and/or flattened vertebras.