Aneurysm of azygos anterior cerebral artery: A report of two cases.

Aneurysms of azygos anterior cerebral artery (ACA) are rare with very few cases reported in medical literature. We report here two cases of aneurysm of azygos ACA among 105 patients with subarachnoid hemorrhage. The two aneurysms were successfully clipped by using the bifrontal basal interhemispheric approach.

Human resources, patient load, and infrastructure at institutions providing diabetic care in India: The India 11-city 9-state study.

BACKGROUND: There is a lack of information on the practice patterns and available human resources and services for screening for eye complications among persons with diabetes in India. OBJECTIVES: The study was undertaken to document existing health care infrastructure and practice patterns for managing diabetes and screening for eye complications. METHODS: This cross-sectional, hospital-based survey was conducted in 11 cities where public and private diabetic care providers were identified. Both multispecialty and standalone diabetic care facilities were included. A semi-structured questionnaire was administered to senior representative(s) of each institution to evaluate parameters using the World Health Organization health systems framework. RESULTS: We interviewed physicians in 73 hospitals (61.6% multispecialty hospitals; 38.4% standalone clinics). Less than a third reported having skilled personnel for direct ophthalmoscopy. About 74% had provision for glycated hemoglobin testing. Only a third had adequate vision charts. Printed protocols on management of diabetes were available only in 31.5% of the facilities. Only one in four facilities had a system for tracking diabetics. Half the facilities reported having access to records from the treating ophthalmologists. Direct observation of the services provided showed that reported figures in relation to availability of patient support services were overestimated by around 10%. Three fourths of the information sheets and half the glycemia monitoring cards contained information on the eye complications and the need for a regular eye examination. CONCLUSIONS: The study highlighted existing gaps in service provision at diabetic care centers in India.

Perceptions and practices related to diabetes reported by persons with diabetes attending diabetic care clinics: The India 11-city 9-state study.

BACKGROUND: India has the second largest population of persons with diabetes and a significant proportion has poor glycemic control and inadequate awareness of management of diabetes. OBJECTIVES: Determine the level of awareness regarding management of diabetes and its complications and diabetic care practices in India. METHODS: The cross-sectional, hospital-based survey was conducted in 11 cities where public and private providers of diabetic care were identified. At each diabetic care facility, 4-6 persons with diabetes were administered a structured questionnaire in the local language. RESULTS: Two hundred and eighty-five persons with diabetes were interviewed. The mean duration since diagnosis of diabetes was 8.1 years (standard deviation ± 7.3). Half of the participants reported a family history of diabetes and 41.7% were hypertensive. Almost 62.1% stated that they received information on diabetes and its management through interpersonal channels. Family history (36.1%), increasing age (25.3%), and stress (22.8%) were the commonest causes of diabetes reported. Only 29.1% stated that they monitored their blood sugar levels at home using a glucometer. The commonest challenges reported in managing diabetes were dietary modifications (67.4%), compliance with medicines (20.5%), and cost of medicines (17.9%). Around 76.5% were aware of complications of diabetes. Kidney failure (79.8%), blindness/vision loss (79.3%), and heart attack (56.4%) were the commonest complications mentioned. Almost 67.7% of the respondents stated that they had had an eye examination earlier. CONCLUSIONS: The findings have significant implications for the organization of diabetes services in India for early detection and management of complications, including eye complications.

Perception of care and barriers to treatment in individuals with diabetic retinopathy in India: 11-city 9-state study.

BACKGROUND: Diabetic retinopathy is a leading cause of visual impairment. Low awareness about the disease and inequitable distribution of care are major challenges in India. OBJECTIVES: Assess perception of care and challenges faced in availing care among diabetics. MATERIALS AND METHODS: The cross-sectional, hospital based survey was conducted in eleven cities. In each city, public and private providers of eye-care were identified. Both multispecialty and standalone facilities were included. Specially designed semi-open ended questionnaires were administered to the clients. RESULTS: 376 diabetics were interviewed in the eye clinics, of whom 62.8% (236) were selected from facilities in cities with a population of 7 million or more. The mean duration of known diabetes was 11.1 (±7.7) years. Half the respondents understood the meaning of adequate glycemic control and 45% reported that they had visual loss when they first presented to an eye facility. Facilities in smaller cities and those with higher educational status were found to be statistically significant predictors of self-reported good/adequate control of diabetes. The correct awareness of glycemic control was significantly high among attending privately-funded facilities and higher educational status. Self-monitoring of glycemic status at home was significantly associated with respondents from larger cities, privately-funded facilities, those who were better educated and reported longer duration of diabetes. Duration of diabetes (41%), poor glycemic control (39.4%) and age (20.7%) were identified as the leading causes of DR. The commonest challenges faced were lifestyle/behavior related. CONCLUSIONS: The findings have significant implications for the organization of diabetes services in India.

Is India's policy framework geared for effective action on avoidable blindness from diabetes?

BACKGROUND: The growing burden of avoidable blindness caused by diabetic retinopathy (DR) needs an effective and holistic policy that reflects mechanisms for early detection and treatment of DR to reduce the risk of blindness. MATERIALS AND METHODS: We performed a comprehensive health policy review to highlight the existing systemic issues that enable policy translation and to assess whether India's policy architecture is geared to address the mounting challenge of DR. We used a keyword-based Internet search for documents available in the last 15 years. Two reviewers independently assessed retrieved policies and extracted contextual and program-oriented information and components delineated in national policy documents. Using a "descriptive analytical" method, the results were collated and summarized as per themes to present status quo, gaps, and recommendations for the future. RESULTS: Lack of focus on building sustainable synergies that require well laid out mechanisms for collaboration within and outside the health sector and poor convergence between national health programs appears to be the weakest links across policy documents. CONCLUSIONS: To reasonably address the issues of consistency, comprehensiveness, clarity, context, connectedness, and sustainability, policies will have to rely more strongly on evidence from operational research to support decisions. There is a need to involve multiple stakeholders from multiple sectors, recognize contributions from not-for-profit sector and private health service providers, and finally bring about a nuanced holistic perspective that has a voice with implementable multiple sector actions.

Micropatterned coumarin polyester thin films direct neurite orientation.

Guidance and migration of cells in the nervous system is imperative for proper development, maturation, and regeneration. In the peripheral nervous system (PNS), it is challenging for axons to bridge critical-sized injury defects to achieve repair and the central nervous system (CNS) has a very limited ability to regenerate after injury because of its innate injury response. The photoreactivity of the coumarin polyester used in this study enables efficient micropatterning using a custom digital micromirror device (DMD) and has been previously shown to be biodegradable, making these thin films ideal for cell guidance substrates with potential for future in vivo applications. With DMD, we fabricated coumarin polyester thin films into 10×20 µm and 15×50 µm micropatterns with depths ranging from 15 to 20 nm to enhance nervous system cell alignment. Adult primary neurons, oligodendrocytes, and astrocytes were isolated from rat brain tissue and seeded onto the polymer surfaces. After 24 h, cell type and neurite alignment were analyzed using phase contrast and fluorescence imaging. There was a significant difference (p<0.0001) in cell process distribution for both emergence angle (from the body of the cell) and orientation angle (at the tip of the growth cone) confirming alignment on patterned surfaces compared to control substrates (unpatterned polymer and glass surfaces). The expected frequency distribution for parallel alignment (≤15°) is 14% and the two micropatterned groups ranged from 42 to 49% alignment for emergence and orientation angle measurements, where the control groups range from 12 to 22% for parallel alignment. Despite depths being 15 to 20 nm, cell processes could sense these topographical changes and preferred to align to certain features of the micropatterns like the plateau/channel interface. As a result this initial study in utilizing these new DMD micropatterned coumarin polyester thin films has proven beneficial as an axon guidance platform for future nervous system regenerative strategies.

Photoresponsive polyesters by incorporation of alkoxyphenacyl or coumarin chromophores along the backbone.

The synthesis and photochemical characterization of two classes of photoresponsive polyesters are described. These polyesters contain either alkoxyphenacyl or coumarin chromophores embedded along the polymer chain. The alkoxyphenacyl polyesters undergo efficient photoinduced chain scission upon irradiation at 300 nm in solution or as a nanoparticle suspension. At 254 nm the coumarin polyesters undergo polymer chain scission. Irradiation of the coumarin polyesters in solution at 350 nm results in both chain crosslinking and chain scission behavior, while irradiation of the coumarin polyesters as nanoparticles results in chain crosslinking. The properties of the alkoxyphenacyl and coumarin polyesters are influenced by the choice of diacid as seen from their thermal behavior. The use of glutamic acid enabled surface or bulk functionalization of the photoresponsive polymers. In addition, controlled release of Nile Red from coumarin polyester nanoparticles is demonstrated by modulation of the wavelength and intensity of irradiation.

Role of free space and conformational control on photoproduct selectivity of optically pure α-alkyldeoxybenzoins within a water-soluble organic capsule.

Optically pure α-alkyl deoxybenzoins resulting in products of Norrish Type I and Type II reactions upon excitation has been investigated within the octa acid (OA) capsule in water. The product distribution was different from that in an organic solvent and was also dependent on the length of the α-alkyl chain. Most importantly, a rearrangement product not formed in an organic solvent arising from the triplet radical pair generated by Norrish Type I reaction was formed, and its yield was dependent on the alkyl chain length. In an organic solvent, since the cage lifetime is shorter than the time required for intersystem crossing (ISC) of the triplet radical pair to the singlet radical pair the recombination with or without rearrangement of the primary radical pair (phenylacetyl and benzyl) does not occur. Recombination without rearrangement within the capsule as inferred from monitoring the racemization of the optically pure α-alkyl deoxybenzoins suggesting the capsule's stability for at least 10(-8) s (the time required for ISC) is consistent with our previous photophysical studies that showed partial opening and closing of the capsule in the time range of microseconds.

Regioselective photodimerization of pyridyl-butadienes within cucurbit[8]uril cavities.

The cucurbit[8]uril (CB8) templation strategy that is known to yield stereoselective photodimers of organic olefins has been extended to substituted butadienes. By virtue of its strong binding interactions with guests the rigid cavity of CB8 is capable of preorienting the diene guests to result in greater yields of stereoselective photodimers upon irradiation. The symmetry of the butadiene monomers influences the relative arrangement of the monomers in complexes leading to the observed product selectivity.

Coverage of hospital-based cataract surgery and barriers to the uptake of surgery among cataract blind persons in nigeria: the Nigeria National Blindness and Visual Impairment Survey.

PURPOSE: To determine cataract surgical coverage, and barriers to modern cataract surgery in Nigeria. METHODS: Multistage stratified cluster random sampling was used to identify a nationally representative sample of 15,027 persons aged 40+ years. All underwent visual acuity testing, frequency doubling technology visual field testing, autorefraction, and measurement of best corrected vision if <6/12 in one or both eyes. An ophthalmologist examined the anterior segment and fundus through an undilated pupil for all participants. Participants were examined by a second ophthalmologist using a slit lamp and dilated fundus examination using a 90 diopter condensing lens if vision was <6/12 in one or both eyes, there were optic disc changes suggestive of glaucoma, and 1 in 7 participants regardless of findings. All those who had undergone cataract surgery were asked where and when this had taken place. Individuals who were severely visually impaired or blind from unoperated cataract were asked to explain why they had not undergone surgery. RESULTS: A total of 13,591 participants were examined (response rate 89.9%). Prevalence of cataract surgery was 1.6% (95% confidence interval 1.4-1.8), significantly higher among those aged ≥70 years. Cataract surgical coverage (persons) in Nigeria was 38.3%. Coverage was 1.7 times higher among males than females. Coverage was only 9.1% among women in the South-South geopolitical zone. Over one third of those who were cataract blind said they could not afford surgery (36%). CONCLUSIONS: Cataract surgical coverage in Nigeria was among the lowest in the world. Urgent initiatives are necessary to improve surgical output and access to surgery.

Quality of life and visual function in Nigeria: findings from the National Survey of Blindness and Visual Impairment.

AIMS: To assess associations of visual function (VF) and quality of life (QOL) by visual acuity (VA), causes of blindness and types of cataract procedures in Nigeria. METHODS: Multi-stage stratified cluster random sampling was used to identify a nationally representative sample of persons aged ≥ 40 years. VF/QOL questionnaires were administered to participants with VA <6/60 in one or both eyes and/or Mehra-Minassian cataract grade 2B or 3 in one or both eyes and a random sample of those with bilateral VA ≥ 6/12. RESULTS: VF/QOL questionnaires were administered to 2076 participants. Spearman's rank correlation showed a strong correlation between decreasing VA and VF/QOL scores (p<0.0001) with greatest impact on social (p<0.0001) and mobility-related activities (p<0.0001). People who were blind due to glaucoma had lower VF and QOL scores than those who were blind due to cataract. Mean VF and QOL scores were lower after couching compared with conventional cataract surgery (mean VF score=51.0 vs 63.0 and mean QOL score=71.3 vs 79.3). Finally, VF and QOL scores were lower among populations with specific characteristics. CONCLUSIONS: Populations with the following characteristics should be targeted to improve VF and QOL: people who are blind, older people, women, manual labourers, people living in rural areas, those living in the northern geopolitical zones, those practising Islamic and Traditionalism faith, those not currently married and those who have undergone couching.

Ecological determinants of blindness in Nigeria: the Nigeria National Blindness and Visual Impairment Survey.

OBJECTIVE: To determine the prevalence and causes of visual loss in different ecological zones across Nigeria. METHODS: A population-based survey using multi-stage, stratified, cluster random sampling with probability proportional to size comprising a nationally representative sample of adults aged > or = 40 years from six ecological zones. OUTCOME MEASURES: Distance vision was measured using reduced logMAR charts. Clinical examination included basic eye examination for all respondents and a detailed examination including visual fields, gonioscopy and fundus photography for those who were visually impaired or blind (i.e. presenting vision < 20/40 in the better eye). A principal cause of visual loss was assigned to all respondents with presenting vision < 20/40 in the better eye. RESULTS: A total of 15 122 persons aged > or = 40 years were enumerated, 13 599 (89.9%) of whom were examined. The prevalence of blindness varied according to ecological zone, being highest in the Sahel region (6.6%; 95% confidence interval (CI) 4.2 - 10.4) and lowest in the rain forest region (3.23%; 95% CI 2.6 - 3.9). Age/ gender-adjusted analyses showed that risk of blindness was highest in Sahel (odds ratio (OR) 3.4; 95% CI 2.1 - 5.8). More than 80% of blindness in all ecological regions was avoidable. Trachoma was a significant cause only in the Sudan savannah belt. The prevalence of all major blinding conditions was highest in the Sahel. CONCLUSIONS: The findings of this national survey may be applicable to other countries in West and Central Africa that share similar ecological zones. Onchocerciasis and trachoma are not major causes of blindness in Nigeria, possibly reflecting successful control efforts for both these neglected tropical diseases.

Closed nanocontainer enables thioketones to phosphoresce at room temperature in aqueous solution.

Thiocarbonyl compounds possess unusual photophysical properties: they fluoresce from S(2), phosphoresce from T(1) only at extremely low concentrations in solution at room temperature, have unit quantum yield of intersystem crossing from S(1) to T(1), undergo self-quenching at diffusion-controlled rates, and are quenched by ground-state oxygen leading to self-destruction. In this article, we are concerned with finding a new method to observe phosphorescence from thioketones at room temperature in aqueous solution at high concentrations. To achieve this goal, one needs to find ways to eliminate diffusion-limited self-quenching and oxygen quenching. We present here a general strategy that has allowed us to record phopshorescence from a number of thioketones in aqueous solution at room temperature. The method involves encapsulation of thioketone molecules within a "closed nanocontainer" made up of two cavitand molecules known by its trivial name as octa acid. In these supramolecular complexes, despite two thiocarbonyl compounds being present in close proximity, no self-quenching occurs within the confined space due to curtailment of their rotational freedom. Although phosphorescence could also be observed when these thioketones are included in open containers, such as cucurbiturils and cyclodextrines, the closed container made up of octa acid is found to be the best medium to observe phosphorescence from thioketones whose excited state chemistry is essentially controlled by self-quenching.

Cavitand octa acid forms a nonpolar capsuleplex dependent on the molecular size and hydrophobicity of the guest.

We have been exploring the use of a deep cavity cavitand known by the trivial name 'octa acid' as a photochemical reaction cavity for manipulating photochemical and photophysical properties of organic molecules. In the current study, we have monitored the micropolarity of the interior of the cavitand by recording the fluorescence of five different organic probes. They all indicate that the interior of octa acid capsuleplex (2:1, H/G complex) is nonpolar and does not contain water molecules in spite of the complex being present in water. The nature of the octa acid-probe complex in each case has been characterized by 1H NMR data to be a 2:1 capsuleplex. Photophysical and 1H NMR experiments were employed to probe the factors that control the structure of the complex, 2:2, 2:1, and 1:1. The data we have on hand suggest that the structure of the host/guest complex depends on the size and hydrophobicity of the guest molecule.

Prevalence of blindness and visual impairment in Nigeria: the National Blindness and Visual Impairment Study.

PURPOSE: To determine the prevalence of blindness and visual impairment among adults aged > or = 40 years in Nigeria. METHODS: Multistage, stratified, cluster random sampling with probability proportional to size procedures was used to identify a cross-sectional nationally representative sample of 15,027 persons > or = 40 years of age from all 36 states in Nigeria and the Federal Capital Territory. Distance visual acuity (VA) was measured with a reduced logMAR tumbling-E chart at 4 and 1 m. Presenting and best corrected visual acuities were recorded. Autorefraction was performed in all examined adults. Clinical evaluations included examination under dilation for those with presenting vision < 6/12 in either eye. RESULTS: In the study, 15,122 persons aged > or = 40 years were enumerated and 13,599 (89.9%) examined. Prevalence of blindness (< 20/400 in the better eye) and severe visual impairment (< 20/200-20/400; presenting vision) was 4.2% (95% confidence interval [CI]: 3.8%-4.6%) and 1.5% (95% CI: 1.3%-1.7%), respectively. Blindness was associated with increasing age, being female, poor literacy, and residence in the North. Participants residing in the South West had the lowest prevalence while those in the North East had the highest prevalence of blindness. It is estimated that 4.25 million adults aged > or = 40 years have moderate to severe visual impairment or blindness (< 20/63 in the better eye). CONCLUSIONS: There is a high prevalence of blindness and severe visual impairment among those aged > or = 40 years in Nigeria. Significant differences exist between the geopolitical zones and emphasis should be on ensuring eye services across Nigeria, which means that planning at the regional level is necessary.

Self aggregation of supramolecules of nitroxides@cucurbit[8]uril revealed by EPR spectra.

Supramolecular complexation behavior of cucurbiturils with paramagnetic nitroxide spin probes was examined by (1)H NMR, X-ray diffraction studies of crystals, computation, and EPR. Both cucurbit[7]uril (CB7) and cucurbit[8]uril (CB8) form a 1:1 complex with 4-(N,N,N-trimethylammonium)-2,2,6,6-tetramethylpiperidinyl-N-oxy bromide (CAT1). The structure of the complex in the solid state was inferred by X-ray diffraction studies and in the gas phase by computation (B3LYP/6-31G(d)). Whereas ESI-MS data provided evidence for the existence of the complex in solution, indirect evidence was obtained through (1)H NMR studies with a structural diamagnetic analogue, 4-(N,N,N-trimethylammonium)-2,2,6,6-tetramethyl-N-methylpiperidine iodide (DCAT1). The EPR spectrum of the CAT1@CB7 complex consisting of three lines suggested that probe CAT1 is associated with host CB7 such that the nitroxide part is exposed to water. The spectral pattern was independent of the concentration of the complex and the presence of salt such as NaCl. The most interesting observation was made with CB8 as the host. In this case, in addition to the expected three-line spectrum, an additional spectrum consisting of seven lines was recorded. The contribution of the seven-line spectrum to the total spectrum was dependent on the concentration of the complex and added salt (NaCl) to the aqueous solution. The coupling constant for the seven-line spectrum for (14)N-substituted CAT1 is 5 G, and that for the four-line spectrum for (15)N-substituted CAT1 is 7.15 G. The only manner by which we could reproduce the observed spectra by simulation for both (14)N- and (15)N-substituted CAT1@CB8 was by assuming a spin exchange among three nitroxide radicals. To account for this observation, we hypothesize that three CAT1 molecules included within CB8 interact in such a way that there is an association of three supramolecules of CAT1@CB8 (i.e., [CAT1@CB8](3)) in a triangular geometry that leads to spin exchange between the three radical centers. We have established, with the help of 13 additional examples, that this is a general phenomenon. We are in the process of understanding this unusual phenomenon.

The Nigerian national blindness and visual impairment survey: Rationale, objectives and detailed methodology.

BACKGROUND: Despite having the largest population in Africa, Nigeria has no accurate population based data to plan and evaluate eye care services. A national survey was undertaken to estimate the prevalence and determine the major causes of blindness and low vision. This paper presents the detailed methodology used during the survey. METHODS: A nationally representative sample of persons aged 40 years and above was selected. Children aged 10-15 years and individuals aged <10 or 16-39 years with visual impairment were also included if they lived in households with an eligible adult. All participants had their height, weight, and blood pressure measured followed by assessment of presenting visual acuity, refractokeratomery, A-scan ultrasonography, visual fields and best corrected visual acuity. Anterior and posterior segments of each eye were examined with a torch and direct ophthalmoscope. Participants with visual acuity of < = 6/12 in one or both eyes underwent detailed examination including applanation tonometry, dilated slit lamp biomicroscopy, lens grading and fundus photography. All those who had undergone cataract surgery were refracted and best corrected vision recorded. Causes of visual impairment by eye and for the individual were determined using a clinical algorithm recommended by the World Health Organization. In addition, 1 in 7 adults also underwent a complete work up as described for those with vision < = 6/12 for constructing a normative data base for Nigerians. DISCUSSION: The field work for the study was completed in 30 months over the period 2005-2007 and covered 305 clusters across the entire country. Concurrently persons 40+ years were examined to form a normative data base. Analysis of the data is currently underway. CONCLUSION: The methodology used was robust and adequate to provide estimates on the prevalence and causes of blindness in Nigeria. The survey would also provide information on barriers to accessing services, quality of life of visually impaired individuals and also provide normative data for Nigerian eyes.

Crystal engineering principles applied to solution photochemistry: controlling the photodimerization of stilbazolium salts within gamma-cyclodextrin and cucurbit[8]uril in water.

Borrowing concepts from crystal engineering techniques we have been able to steer the photodimerization of stilbazolium salts included in gamma-cyclodextrin towards a desired dimer.