Implementation of a clinical pathway for the surgical treatment of colorectal cancer during the COVID-19 pandemic.

AIM: This report summarizes the early experience of implementing elective colorectal cancer surgery during the COVID-19 pandemic. METHODS: A pathway to minimize the risk of including COVID-19-positive patients for elective surgery was established. Prioritization and additional safety measures were introduced into clinical practice. Minimal invasive surgery was used where appropriate. RESULTS: Thirty-eight patients were prioritized, and 23 patients underwent surgery (eight colon, 14 rectal and one anal cancer). The minimal invasive surgery rate was 78%. There were no major postoperative complications or patients diagnosed with COVID-19. Histopathological outcomes were similar to normal practice. CONCLUSION: A safe pathway to offer standard high-quality surgery to colorectal cancer patients during the COVID-19 pandemic is feasible.

A nontransfusional perioperative management regimen for patients with sickle cell disease undergoing laparoscopic cholecystectomy.

BACKGROUND: Patients with sickle cell disease (SCD) are at increased risk for cholelithiasis. Laparoscopic cholecystectomy is the most frequent general surgical operation performed for this group of patients. Acute chest syndrome (ACS) is the most common cause of postoperative death among SCD patients. This study aimed to evaluate the impact of a novel perioperative management regimen involving prophylactic continuous positive airways pressure (CPAP) ventilation and avoidance of preoperative blood transfusion on postoperative SCD-related complications after laparoscopic cholecystectomy. METHODS: A retrospective study included all SCD patients who underwent laparoscopic cholecystectomy since 1997 at our institution. Medical notes were analyzed to assess the rates of postoperative complications in relation to the severity of SCD. RESULTS: A total of 13 patients were identified. There were no recorded episodes of acute painful crises and only one patient experienced an episode of ACS requiring protracted CPAP. CONCLUSION: Laparoscopic cholecystectomy can be safely performed for SCD patients without prior blood transfusion. A defined perioperative regimen including the use of routine postoperative prophylactic CPAP for these patients helps to reduce SCD-related postoperative complications such as ACS and painful vaso-occlusive crises.

Effect of 220Rn gas concentration distribution on its transmission from a delay chamber: evolving a CFD-based uniformity index.

(220)Rn mitigation can be achieved by delay chamber technique, which relies on the advantage of its short half-life. However, flow rate as well as inlet-outlet position for the delay chamber can have a significant impact on (220)Rn concentration distribution patterns and hence transmission factor. In the present study, computational fluid dynamics simulations to estimate the concentration distribution has been carried out in a chamber of 0.5 m(3) for the combination of six different inlet-outlet positions and five different flow rates. Subsequently, the transmission factor (TF) for the chamber was evaluated and found to be highly dependent on the flow rate and inlet-outlet positions. For ease of scale up, the dependency of TF on the flow rate and the inlet-outlet positions is best summarised by relative transmission factor (RTF), which is the ratio of the TFs for the case of inlet and outlet on different faces to that on the same face.

Sentinel node biopsy can replace four-node-sampling in staging early breast cancer.

AIM: Four-node axillary sampling for breast cancer is an established method of staging the axilla in the United Kingdom. We report the sensitivity of sentinel node (SN) biopsy and compare it with that of four-node sampling. METHODS: SN identification was attempted in 234 consecutive patients with unifocal breast cancers up to 25 mm in diameter on pre-operative ultrasound. A combination of isotope-labelled nanocolloid and patent blue dye techniques were used and SN were identified in 221 (94.5%). All patients underwent back-up four-node sampling and those with positive sentinel nodes on frozen section (FS) underwent immediate full axillary clearance. RESULTS: Among those patients who had SN successfully identified, an average of 1.38 SN were identified per patient. Histological examination of the SN alone would have identified all node-positive patients that the four-node sample identified. CONCLUSION: In patients who have SN identified, four-node axillary sampling does not provide any additional information.

Molecular Modeling and Docking Study to Elucidate Novel Chikungunya Virus nsP2 Protease Inhibitors.

Chikungunya is one of the tropical viral infections that severely affect the Asian and African countries. Absence of any suitable drugs or vaccines against Chikungunya virus till date makes it essential to identify and develop novel leads for the same. Recently, nsP2 cysteine protease has been classified as a crucial drug target to combat infections caused by Alphaviruses including Chikungunya virus due to its involvement viral replication. Here in, we investigated the structural aspects of the nsP2 protease through homology modeling based on nsP2 protease from Venezuelan equine encephalitis virus. Further, the ligands were virtually screened based on various pharmacological, ADME/Tox filters and subjected to docking with the modeled Chikungunya nsP2 protease using AutoDock4.2. The interaction profiling of ligand with the protein was carried out using LigPlot(+). The results demonstrated that the ligand with PubChem Id (CID_5808891) possessed highest binding affinity towards Chikungunya nsP2 protease with a good interaction profile with the active site residues. We hereby propose that these compounds could inhibit the nsP2 protease by binding to its active site. Moreover, they may provide structural scaffold for the design of novel leads with better efficacy and specificity for the nsP2 protease.

Molecular Docking and Interactions of Pueraria Tuberosa with Vascular Endothelial Growth Factor Receptors.

Pueraria tuberosa is known for its therapeutic potentials in cardiovascular disorders, but its effect in angiogenesis has not been studied so far. In this study, a computational approach has been applied to elucidate the role of the phytochemicals in inhibition of angiogenesis through modulation of vascular endothelial growth factor receptors: Vascular endothelial growth factor receptor-1 and vascular endothelial growth factor receptor-2, major factors responsible for angiogenesis. Metabolite structures retrieved from PubChem and KNApSAcK - 3D databases, were docked using AutoDock4.2 tool. Hydrogen bond and molecular docking, absorption, distribution, metabolism and excretion and toxicity predictions were carried out using UCSF Chimera, LigPlot(+) and PreADMET server, respectively. From the docking analysis, it was observed that puerarone and tuberostan had significant binding affinity for the intracellular kinase domain of vascular endothelial growth factor receptors-1 and vascular endothelial growth factor receptor-2 respectively. It is important to mention that both the phytochemicals shared similar interaction profile as that of standard inhibitors of vascular endothelial growth factor receptors. Also, both puerarone and tuberostan interacted with Lys861/Lys868 (adenosine 5'-triphosphate binding site of vascular endothelial growth factor receptors-1/vascular endothelial growth factor receptors-2), thus providing a clue that they may enforce their inhibitory effect by blocking the adenosine 5'-triphosphate binding domain of vascular endothelial growth factor receptors. Moreover, these molecules exhibited good drug-likeness, absorption, distribution, metabolism and excretion properties without any carcinogenic and toxic effects. The interaction pattern of the puerarone and tuberostan may provide a hint for a novel drug design for vascular endothelial growth factor tyrosine kinase receptors with better specificity to treat angiogenic disorders.

Core biopsy versus FNAC for palpable breast cancers. Is image guidance necessary?

The aim of this study was to assess the efficacy of free-hand percutaneous core biopsy (FHCB) and to determine the role of fine needle aspiration cytology (FNAC) as diagnostic tools for palpable radiologically-suspicious breast lumps. This retrospective study was based on reviewing the clinical records of all patients diagnosed as having breast cancer between January 1999 and December 2000 and patients who had benign lesions, but suspicious breast imaging at triple assessment. Absolute sensitivity of FHCB for diagnosing cancer in palpable lesions was 98.7% compared with 51.3% for FNAC. The difference in the sensitivity of FHCB and FNAC was statistically significant (P<0.005, Wilcoxon matched pair test). Since 94.8% of radiologically-suspicious lumps were shown to be cancers, we advocate FHCB for all patients presenting with radiologically suspicious palpable lumps to our breast clinic. We also conclude that the sensitivity of FHCB for the diagnosis of malignancy in palpable radiologically-suspicious breast lesions is so high that image-guidance is unnecessary.

Laser in situ keratomileusis for residual myopia after primary LASIK.

PURPOSE: To analyze the results of secondary laser in situ keratomileusis (LASIK) for residual myopia after primary LASIK. SETTING: Dr. Agarwal's Eye Hospital, Chennai, India. METHODS: A retrospective study of 50 eyes of 29 patients who had a secondary LASIK procedure was carried out. After a mean follow-up of 5.84 months +/- 3.24 (SD) after the primary procedure, the mean myopic residual refraction was -4.30 +/- 1.83 diopters (D). In 10 eyes, the primary corneal flap was lifted by blunt dissection. In 40 eyes, the flap was made with a second cut. The secondary LASIK was performed using the Chiron Technolas Keracor 217 excimer laser and the Automated Corneal Shaper microkeratome (Bausch & Lomb). RESULTS: The mean follow-up was 16.58 +/- 3.06 months. At 12 months, the mean spherical equivalent was -0.45 +/- 0.68 D (P <.05). Thirty-one eyes were emmetropic, 13 eyes were within +/-1.00 D of emmetropia, and 5 eyes were within +/-2.00 D. The mean uncorrected visual acuity improved from 20/80 (range 20/60 to 20/200) to 20/40 (range 20/20 to 20/200) (P <.005). Seventeen eyes gained 1 line of best spectacle-corrected visual acuity; 1 eye lost 1 line because of a decentered ablation with an induced postoperative astigmatism of -3.50 D cylinder. No sight-threatening complications such as a free cap, flap irregularity, corneal ectasia, or retinal complication occurred postoperatively. Epithelial ingrowth developed in 5 eyes and corneal thinning, in 1 eye. Three eyes had night glare. CONCLUSION: Secondary LASIK was a safe, stable, and effective method for the treatment of residual myopia after primary LASIK.

Laser in situ keratomileusis for residual myopia after radial keratotomy and photorefractive keratectomy.

PURPOSE: To evaluate the visual outcome, stability, and complications of laser in situ keratomileusis (LASIK) for residual myopia after radial keratotomy (RK) and photorefractive keratectomy (PRK). SETTING: Dr. Agarwal's Eye Hospital, Chennai, India. METHODS: Twenty eyes that had LASIK treatment for residual myopia after RK (10 eyes) or PRK (10 eyes) were retrospectively analyzed. Laser in situ keratomileusis was performed after a mean period of 24.3 months +/- 0.75 (SD) in the RK group and 22.0 +/- 1.07 months in the PRK group. RESULTS: At the last follow-up, the mean spherical equivalent was reduced from -6.05 +/- 1.98 diopters (D) to -1.26 +/- 0.32 D (P <.05) in the RK group and from -3.38 +/- 1.30 D to -0.55 +/- 0.40 D (P <.005) in the PRK group. The mean uncorrected visual acuity improved from 20/300 (range 20/600 to 20/200) to 20/40 (range 20/60 to 20/20) (P <.05) and from 20/200 (range 20/800 to 20/80) to 20/25 (range 20/40 to 20/20) (P <.05), respectively. Two eyes in the RK group and 3 in the PRK group gained 1 line of best corrected visual acuity, and 2 eyes in the RK group lost 1 line. No sight-threatening complications such as a free flap, corneal ectasia, or a retinal complication occurred. There was no statistically significant difference in corneal haze before and after LASIK. Two eyes in the RK group required repositioning of the flap because of irregular apposition to the stromal bed. CONCLUSION: Laser in situ keratomileusis was safe, effective, and stable in the treatment of residual myopia after RK and PRK.

Results of pediatric laser in situ keratomileusis.

PURPOSE: To evaluate the results of laser in situ keratomileusis (LASIK) for uniocular high myopia in pediatric eyes. SETTING: Dr. Agarwal's Eye Hospital, Chennai (Madras), India. METHODS: Sixteen eyes that were treated by LASIK for uniocular high myopia were retrospectively analyzed. The mean patient age was 8.4 years +/- 1.83 (SD) (range 5 to 11 years). Laser in situ keratomileusis was performed using the Technolas Keracor 217 excimer laser and the Automated Corneal Shaper microkeratome, which created a 160 microm corneal lamellar flap. Postoperatively, patients were reviewed at 1 day, 1 week, and 1, 6, and 12 months. The examination included uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), refraction, anterior segment evaluation, grading of haze based on a 5-point scale, intraocular pressure, corneal topography, and fundus evaluation. The Student t test was used for statistical analysis. RESULTS: The charts of all patients were analyzed at the 12 month visit. The mean preoperative spherical equivalent (SE) was -14.88 +/- 3.69 diopters (D) (range -9.00 to -23.00 D) and the mean postoperative SE, -1.44 +/- 1.14 D (range 0 to -2.50 D) (P < .05). The safety index was 1.01 (mean postoperative BCVA 0.54 and mean preoperative BCVA 0.53; P = .77). The efficacy index was 0.53 (mean postoperative UCVA 0.28 and mean preoperative BCVA 0.53). None of the eyes had an induced astigmatism of more than 0.5 D. Twelve eyes regained their BCVA, 2 lost 1 line of BCVA, and 2 gained 1 line. Three eyes had grade 2 haze. No retinal complications were observed. CONCLUSION: In this study, LASIK for uniocular high myopia in pediatric eyes provided encouraging results in the management of select cases of anisometropic amblyopia when other measures failed. A larger study with a longer follow-up is necessary to determine the long-term effects.

Ultrasound biomicroscopy in lens "coloboma".

PURPOSE: To study the morphology of the Lens "Coloboma" using the technique of ultrasound biomicroscopy. METHODS: We used the Paradigm 40 Ultrasound biomicroscope to study the morphology of the lens "Coloboma". RESULTS: Ultrasound biomicroscopy of the lens "Coloboma" revealed a greatly increased sphericity of the lens and the deficiency of zonules in the "colobomatous" area. CONCLUSIONS: Ultrasound biomicroscopy has helped in elucidating the pathology of the lens "Coloboma".

Cardiac autonomic neuropathy and its correlation with QTc dispersion in type 2 diabetes.

This study was conducted on 50 patients of diabetes mellitus type 2 and 20 healthy controls to correlate severity of diabetic cardiac autonomic neuropathy with QTc interval and QTc dispersion. Five standard cardiovascular response tests were carried out (i.e. Valsalva ratio, expiration-inspiration ratio, immediate heart rate response to standing, fall of systolic blood pressure on standing and sustained hand grip test) to determine the severity of cardiac autonomic neuropathy by scoring system. QTc dispersion was determined by subtracting heart rate-corrected minimum QTc interval (QTc min) from maximum QT interval (QTc max) from standard electrocardiogram. Severity of cardiac autonomic neuropathy strongly correlated with QTc dispersion (r = 0.760; p = 0.0001). Correlation of severity of cardiac autonomic neuropathy with QTc max and QTc mean was also found but weaker than with QTc dispersion (r = 0.663, r = 0.542, p = 0.0001 each) and no correlation was found with QTc min (r = 0.177; p = 0.17). This shows that QTc dispersion is a better predictor of cardiac autonomic neuropathy than any of above three QTc intervals. QTc max, QTc mean and QTc dispersion were significantly higher (p < 0.001) in diabetics with autonomic neuropathy (450 +/- 23, 423 +/- 22 and 57 +/- 12 msec; n = 30) than without neuropathy (407 +/- 14, 397 +/- 15 and 20 +/- 7 msec; n = 20) and control subjects (408 +/- 20, 399 +/- 19 and 19 +/- 7 msec; n = 20) but QTc min remained same in the three groups (393 +/- 21, 387 +/- 12, 388 +/- 19 msec, respectively) (p > 0.05). Correlation of QTc dispersion was stronger with QTc max (r = 0.781; p < 0.001) than QTc mean (r = 0.625; p = 0.001) but not with QTc min (r = 0.097; p = 1.0) which suggests that regional increase in QT interval due to regional autonomic denervation leads to increased QTc dispersion. Thus, QTc dispersion is a sensitive, non-invasive, simple and cost-effective predictor of cardiac dysautonomia.

Vitrectomy for intra ocular foreign body removal.

Ten consecutive cases of perforating ocular injuries with retained intraocular foreign bodies over a period of 2 years were reviewed retrospectively in this study. All cases were operated upon by a 3 port pars plana vitrectomy and if necessary endolaser done. All ten cases (100%) were successful in terms of intraocular foreign body removal through the pars plana sclerotomy but ultimately we lost three [3] [30%] cases of which two had retinal detachments with P.V.R. D-3 preoperatively and the other had endophthalmitis. Of the seven (70%) successful cases four eyes (40%) had a post-operative vision of 6/12 or better while 2 [20%] had 6/24 and the last had 6/60 [10%]. Nine cases [90%] had a magnetic Intraocular foreign body. Various complications of Intraocular foreign bodies like vitreous haemorrhage, retinal incarceration, cataract and retinal detachment were noted preoperatively. Silicone oil was used in three (30%) cases. Sulfur Hexafluoride was used in 5 cases (50%). Endolaser photocoagulation was done in 7 cases (70%).

An epidemiologic study of intermittent acute porphyria in Maheshwari community of Napasar, Bikaner (Rajasthan)

An epidemiologic study of intermittent acute porphyria in the Maheshwari community of Napasar, Bikaner (Rajasthan) was conducted. Twelve cases were detected among 1900 persons belonging to ten families surveyed (prevalence 1:408). The disease was more common in females and the maximum number (4 cases) was encountered in the age group 21-30 years. The disease was more common in Mundhra (4 cases) and Mohata (3 cases) subcastes.

Poor diagnostic accuracy and applicability of Siriraj stroke score, Allen score and their combination in differentiating acute haemorrhagic and thrombotic stroke.

OBJECTIVE: To evaluate the relevance of bed side clinical diagnostic scoring systems--Siriraj stroke score (SSS), Allen score and their combined use for differentiating acute haemorrhagic and thrombotic stroke. MATERIAL AND METHODS: The study was conducted on 240 admitted patients of stroke over a period of two years. SSS was calculated immediately and Allen score, 24 hours after admission. CT scan was done immediately and 48 hours after admission if required. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic gain were calculated for both the scores. Comparability between the scores and CT scan finding was determined with the help of kappa statistic programme. Receiver operating characteristic curves (ROC) were plotted to assess the diagnostic accuracy of both scores over a range of cut-off points. RESULTS: One hundred and thirty four patients (55.83%) had infarction and 106 patients (44.17%) had haemorrhage. SSS was applicable in 66.25% patients (159 out of 240) while Allen score was applicable in only 61.25% patients (147 our of 240). The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic gain for SSS were 73%, 85%, 85%, 71% and 30% for infarction and 85%, 73%, 71%, 85% and 27% for haemorrhage respectively, whereas the corresponding figures for Allen score were 91%, 60%, 77%, 82% and 18% for infarction and 60%, 91%, 82%, 77% and 41% for haemorrhage respectively. There was overall moderate comparability between SSS and Allen score for diagnosing supratentorial stroke (k = 0.396). The comparability of these scores in terms of certain results was worse (k = 0.143). However when the results that were within the diagnostic range with both the scores were considered, the agreement in diagnosing infarction and haemorrhage was almost perfect (k = 0.874). While considering CT scan finding as gold standard for differentiation of infarction and haemorrhage, the overall accuracy of SSS and Allen score was seventy eight percent. CONCLUSION: (a) Applicability of SSS only in 66.25% patients and wrong diagnosis in 22.01% patients does not reflect its usefulness because adequate management of stroke requires a gold standard diagnosis which is only possible by immediate CT scan. (b) Allen score is not useful because it can be assessed only after 24 hours of onset of stroke. This deprives the management to all thrombotic patients in speculated time window of modern management.

CFD based simulation of thoron ((220)Rn) concentration in a delay chamber for mitigation application.

The release of (220)Rn gas (conventionally referred to as thoron) is an issue of concern from the radiological point of view for occupational environments pertaining to the thorium fuel cycle. Studies for understanding its release and developing systems to control it are crucial for exposure control research. A thorough study of the "Delay Volume Technique" for mitigation of (220)Rn has been carried out. Experiments have been carried out with (220)Rn source and associated measurement system in a cubical chamber (delay chamber) of 0.5 m(3) volume. For different flow conditions and inlet-outlet positions, (220)Rn transmission factor has been obtained. Computational Fluid Dynamics (CFD) technique has been employed for these experimental conditions and the simulated transmission factors have been compared. The results show that the flow and the position of the inlet and outlet play an imperative role in the transportation, mixing and subsequent mitigation of thoron inside the chamber. Predictive capability of CFD technique for such delay volume experiments has been validated in this work. A comparison has been made with uniform mixing model and it is found that the results of simulation differ appreciably from that of uniform mixing model at the tested flow regime.

Study of indoor radon distribution using measurements and CFD modeling.

Measurement and/or prediction of indoor radon ((222)Rn) concentration are important due to the impact of radon on indoor air quality and consequent inhalation hazard. In recent times, computational fluid dynamics (CFD) based modeling has become the cost effective replacement of experimental methods for the prediction and visualization of indoor pollutant distribution. The aim of this study is to implement CFD based modeling for studying indoor radon gas distribution. This study focuses on comparison of experimentally measured and CFD modeling predicted spatial distribution of radon concentration for a model test room. The key inputs for simulation viz. radon exhalation rate and ventilation rate were measured as a part of this study. Validation experiments were performed by measuring radon concentration at different locations of test room using active (continuous radon monitor) and passive (pin-hole dosimeters) techniques. Modeling predictions have been found to be reasonably matching with the measurement results. The validated model can be used to understand and study factors affecting indoor radon distribution for more realistic indoor environment.

Management of perianal abscess and fistula-in-ano in children.

INTRODUCTION: Perianal abscess (PA) and fistula-in-ano (FIA) are common acquired anorectal disorders in children, but their management is still controversial. This study was performed to evaluate our experience with the treatment of PA and FIA in children of different age groups. MATERIAL AND METHODS: A retrospective study was conducted of children below 16 years of age treated for PA/FIA in a pediatric surgery center between January 2002 and April 2006. The standard treatment for PA was incision and drainage (I&D). Judicious probing for fistulae was only performed in recurrent abscess or if a discharge of pus was identified from the anal verge at surgery. Fistulotomy was routinely performed in low fistulae not associated with inflammatory bowel disease (IBD). IBD associated fistulae were treated with topical tacrolimus in the absence of deep seated infection. Patients were divided into 3 age groups: <2 years, 2-8 years and >8 years. Mode of treatment, microbial organisms, recurrence, associated FIA and association with IBD were recorded. The median follow-up period was 6 months (8 weeks-3 years). Fisher's exact test was used for the analysis of categorical variables. RESULTS: A total of 78 (39 [<2 years]; 17 [2-8 years]; 22 [>8 years]) patients were treated for PA/FIA during the four year period. In children aged <2 years, 33 (85%) had I&D of PA and the other 6 (15%) had fistulotomy. Recurrence was seen in 9 (23%) children, of which 3 (8%) had FIA. In children aged 2-8 years, 13 (76%) had PA and 4 (24%) had a FIA and there were no recurrences. In children >8 years, 12 (55%) had I&D, 1 (4%) had a fistulotomy and 9 (41%) were treated non-surgically. Six of 7 patients with IBD associated FIA were treated successfully with topical tacrolimus. The recurrence rate after primary surgery was significantly higher for <2 years and >8 years age groups compared to the 2-8 years age group. The incidence of FIA identified either at primary operation or during exploration for recurrence was highest (50%) in >8 years age group and lowest (21%) in the <2 years age group. Lactose fermenting coliforms were the most common organisms isolated from pus. The presence of intestinal organisms in pus was associated with significantly higher recurrence rates in children aged <2 years. CONCLUSIONS: Surgery for PA/FIA in children aged <2 years resulted in low recurrence rates and should be considered as the primary treatment. Topical tacrolimus was found to be an effective treatment for IBD associated FIA.