Monitoring cerebral oxygenation during balloon occlusion with multichannel NIRS

We report on oxygenation changes noninvasively recorded by multichannel continuous-wave near infrared spectroscopy (CW-NIRS) during endovascular neuroradiologic interventions requiring temporary balloon occlusion of arteries supplying the cerebral circulation. Digital subtraction angiography (DSA) provides reference data on the site, timing, and effectiveness of the flow stagnation as well as on the amount and direction of collateral circulation. This setting allows us to relate CW-NIRS findings to brain specific perfusion changes. We focused our analysis on the transition from normal perfusion to vessel occlusion, i.e., before hypoxia becomes clinically apparent. The localization of the maximal response correlated either with the core (occlusion of the middle cerebral artery) or with the watershed areas (occlusion of the internal carotid artery) of the respective vascular territories. In one patient with clinically and angiographically confirmed insufficient collateral flow during carotid artery occlusion, the total hemoglobin concentration became significantly asymmetric, with decreased values in the ipsilateral watershed area and contralaterally increased values. Multichannel CW-NIRS monitoring might serve as an objective and early predictive marker of critical perfusion changes during interventions—to prevent hypoxic damage of the brain. It also might provide valuable human reference data on oxygenation changes as they typically occur during acute stroke.     

Comparative study of pulsatile and nonpulsatile flow during cardio-pulmonary bypass

The use of nonpulsatile flow during extracorporeal circulation remains popular despite theoretical advantages of pulsatile cardiopulmonary bypass (CPB). Pulsatile CPB is considered to be more physiological than nonpulsatile flow as the pulsatile energy ensures the patency of the vascular bed and mechanical motion of tissue fluid around the cell membrane, improves microcirculation and enhances diffusion. The purpose of this study was to compare the effect of pulsatile and nonpulsatile flow on the coagulation profile, liver and kidney function and also on the haemodynamics in patients undergoing coronary artery bypass grafting on CPB. One hundred patients between 35 and 65 years of age with normal left ventricular function were randomly divided into two equal groups: Pulsatile (P) and nonpulsatile (NP). Haematological parameters, clotting profile, renal parameters, hepatic function tests and haemodynamic variables were measured preoperatively and postoperatively at specific intervals. Surgical, anaesthetic and CPB regimen was standard in all cases. There was a decrease in platelet count during and after CPB in both groups. Coagulation profile and renal function parameters remained similar in both groups except that creatinine clearance was better in group P on the first postoperative day. Urine output was also better in group P. There was no change in liver function tests in both groups. The haemodynamic variables were comparable in both groups. The systemic vascular resistance was higher in group NP postoperatively and oxygen consumption was higher in group P post CPB. In conclusion we did not find any significant difference between pulsatile and nonpulsatile flow during CPB except the creatinine clearance and urine output were better in pulsatile group.     

Physiologic Changes of the Anorectum After Pelvic Radiotherapy for the Treatment of Prostate and Bladder Cancer

INTRODUCTION: The effect of pelvic radiotherapy on anorectal function is not clearly documented and is investigated in this prospective study. METHODS: Thirty-one males (median age, 70 years) with carcinoma of the prostate (n = 28) and bladder (n = 3) completed proctitis/incontinence symptom score questionnaires and anorectal physiology studies before and six weeks after pelvic radiotherapy. At six months after completion of radiotherapy, 25 of these patients were studied again. The results were expressed as medians and ranges and compared by the Mann-Whitney U test (2-tailed). RESULTS: Six weeks and six months after treatment, respectively, the proctitis symptom scores (0 (0-4) vs. 2 (0-7) (P < 0.001) vs. 2 (0-5) (P < 0.001)) and the incontinence symptom scores (0 (0-5) vs. 4 (0-11) (P < 0.001) vs. 3 (0-14) (P < 0.001)) increased. Urgency, frequency of defecation, anorectal pain, incontinence to liquid stool and to flatus, and alteration in lifestyle were significant symptoms after treatment. The following measurements decreased: anal canal resting pressure (83 (35-137) vs. 79 (26-152) (P = NS) vs. 71 (29-97) (P < 0.01) cm H2O), the squeeze increment (152 (51-135) vs. 162 (63-321) (P = NS) vs. 108 (45-296) (P < 0.042) cm H2O), and the maximum tolerated rectal volume (245 (115-450) vs. 194 (112-344) (P < 0.05) vs. 200 (109-350) (P < 0.138) ml). The rectal electrosensory threshold increased (20 (5.4-44) vs. 22 (9-50.5) (P < 0.134) vs. 31.5 (13.6-76) (P < 0.001) mA). CONCLUSIONS: Anorectal symptoms at six weeks after pelvic radiotherapy are related to reduced rectal capacity and compounded at six months by diminished internal and external sphincter function and rectal mucosal sensitivity.     

Morbidity compression or expansion? A temporal analysis of the age at onset of non-communicable diseases in India

While there is evidence of morbidity compression in many countries, temporal patterns of non-communicable diseases (NCDs) in developing countries, such as India, are less clear. Age at onset of disease offers insights to understanding epidemiologic trends and is a key input for public health programs. Changes in age at onset and duration of major NCDs were estimated for 2004 (n = 38,044) and 2018 (n = 43,239) using health surveys from the India National Sample Survey (NSS). Survival regression models were used to compare trends by sociodemographic characteristics. Comparing 2004 to 2018, there were reductions in age at onset and increases in duration for overall and cause-specific NCDs. Median age at onset decreased for NCDs overall (57 to 53 years) and for diabetes, hypertension, heart disease, asthma, mental diseases, eye disease, and bone disease in the range of 2–7 years and increased for cancer, neurological disorders, some genitourinary disorders, and injuries/accidents in the range of 2–14 years. Hazards of NCDs were higher among females for cancers (HR 1.51, 95% CI 1.19–1.90) and neurological disorders (HR 1.18, 95% CI 1.06–1.32) but lower for heart diseases (HR 0.88, 95% CI 0.79–0.97) and injuries/accidents (HR 0.87, 95% CI 0.77–0.99). Hazards were greater among those with lower educational attainment at younger ages and higher educational attainment later in life. Unlike many countries, chronic disease morbidity may be expanding in India for many chronic diseases, indicating excess strain on the health system. Public health programs should focus on early diagnosis and prevention of NCDs.

     

Enhanced electron transfer mediated detection of hydrogen peroxide using a silver nanoparticle–reduced graphene oxide–polyaniline fabricated electrochemical sensor

The current study aims at the development of an electrochemical sensor based on a silver nanoparticle–reduced graphene oxide–polyaniline (AgNPs–rGO–PANI) nanocomposite for the sensitive and selective detection of hydrogen peroxide (H₂O₂). The nanocomposite was fabricated by simple in situ synthesis of PANI at the surface of rGO sheet which was followed by stirring with AEC biosynthesized AgNPs to form a nanocomposite. The AgNPs, GO, rGO, PANI, rGO–PANI, and AgNPs–rGO–PANI nanocomposite and their interaction were studied by UV-vis, FTIR, XRD, SEM, EDX and XPS analysis. AgNPs–rGO–PANI nanocomposite was loaded (0.5 mg cm⁻²) on a glassy carbon electrode (GCE) where the active surface area was maintained at 0.2 cm² for investigation of the electrochemical properties. It was found that AgNPs–rGO–PANI–GCE had high sensitivity towards the reduction of H₂O₂ than AgNPs–rGO which occurred at −0.4 V vs. SCE due to the presence of PANI (AgNPs have direct electronic interaction with N atom of the PANI backbone) which enhanced the rate of transfer of electron during the electrochemical reduction of H₂O₂. The calibration plots of H₂O₂ electrochemical detection was established in the range of 0.01 μM to 1000 μM (R² = 0.99) with a detection limit of 50 nM, the response time of about 5 s at a signal-to-noise ratio (S/N = 3). The sensitivity was calculated as 14.7 μA mM⁻¹ cm⁻² which indicated a significant potential as a non-enzymatic H₂O₂ sensor.

The current study aims at the development of an electrochemical sensor based on a silver nanoparticle–reduced graphene oxide–polyaniline (AgNPs–rGO–PANI) nanocomposite for the sensitive and selective detection of hydrogen peroxide (H₂O₂).     

Orbital apex osteodural fistula - An unusual surgical access

Dural arteriovenous fistulas (DAVFs) are fistulas connecting the branches of dural arteries to dural veins or a venous sinus. Osteodural fistulas are a rare subset of this group of diseases. We wish to report a rare case of an osteodural arteriovenous fistula at the foot of the superior ophthalmic vein (SOV), treatment of which required an unusual surgical approach via the orbit and SOV. Though access for endovascular treatment via the SOV for treatment of caroticocavernous fistulas is reported, the external approach is relatively infrequently performed, outside Europe and the Americas, with this being the first reported procedure from the Indian subcontinent. We wish to explain the steps of this unusual surgical access and highlight the salient precautions and pitfalls in the technique.     

Choroidal thickness profile in healthy Indian children

Purpose:

The purpose was to study choroidal thickness and its profile based on location in healthy Indian children using enhanced depth spectral-domain-optical coherence tomography (SD-OCT).

Methods:

In this cross-sectional observational study 255 eyes of 136 children with no retinal or choroidal disease were consecutively scanned using enhanced depth SD-OCT. Eyes with any ocular disease or axial length (AXL) >25 mm or < 20 mm were excluded. A single observer measured choroidal thickness from the posterior edge of the retinal pigment epithelium to the choroid/sclera junction at 500-microns intervals up to 2500 microns temporal and nasal to the fovea. Generalized estimating equations were used to evaluate the correlation between choroidal thickness at various locations and age, AXL, gender and spherical equivalent (SEq).

Results:

Mean age of the subjects was 11.9 ± 3.4 years (range: 5–18 years). There were 62 Females and 74 males. The mean AXL was 23.55 ± 0.74 mm. Mean subfoveal choroidal thickness was 312.1 ± 45.40 μm. Choroid was found to be thickest subfoveally, then temporally. Age, AXL and SEq showed a significant correlation with choroidal thickness, whereas gender did not affect choroidal thickness.

Conclusion:

Our study provides a valid normative database of choroidal thickness in healthy Indian children. This database could be useful for further studies evaluating choroidal changes in various chorioretinal disorders. Age and AXL are critical factors, which negatively correlated with choroidal thickness.