A Model with Feedback Mechanism for Learning Hand-Eye Coordination: A Pilot Study.

BACKGROUND: Practicing neuroendoscopic skills like hand-eye coordination is mandatory before embarking on actual surgeries. Synthetic models are able alternatives for cadavers and animals. Presently available models in the literature are either very costly or lack a feedback mechanism, which makes training difficult. OBJECTIVE: We aimed to make a basic low-cost neuroendoscopic hand-eye coordination model with a feedback mechanism. METHODS AND MATERIALS: An electronic circuit in series was designed inside a clay utensil to test inadvertent contact of the working instrument with implanted steel pins, which on completion lighted a light-emitting diode (LED) and raised an alarm. Two exercises-moving-a-rubber exercise and passing copper rings of multiple sizes were made and tested by 15 neurosurgeons. RESULTS: The moving-a-rubber exercise was completed by 6/15 (40%) neurosurgeons in the first attempt, 6/15 (40%) in the second, and 3/15 (20%) in the third attempt. For the 1.5 cm copper ring passing exercise, 12/15 (80%) successfully performed in the first attempt; for 1 cm copper ring, 6/15 (40%) performed in the first; and for the 0.5 cm copper ring, 1/15 (6.6%) performed in the first attempt. The time to finish all the exercises significantly decreased in the third successful attempt compared to the first. CONCLUSION: The model gave excellent feedback to the trainee and examiner for basic neuroendoscopic hand-eye coordination skills.

Endoscopic Management of Chronic Subdural Hematoma Using a Novel Brain Retractor.

BACKGROUND: Endoscopic procedures are useful in chronic subdural hematoma especially when there are septations, solid/organized hematoma, and the presence of bridging or neovessels in the cavity. Visualizing the distal hematoma cavity by a rigid scope is challenging in large and curved ones due to the hindrance by the brain surface. Combining rigid endoscopy and brain retractor can overcome this limitation. METHODS: A retrospective study of 248 patients managed by endoscopic technique was performed and the relevant literature was reviewed. RESULTS: The brain retractor was used in all patients. Average operative time, subgaleal drainage duration, and hospital stay were 56 minutes, 3.1 days, and 4.6 days, respectively. The average preoperative Glasgow coma scale (GCS) score was 12, which improved to 14 and 15 in 223 and 23 patients, respectively at discharge. There were solid clots, septations, bridging vessels, curved hematoma cavities, rapid expansion of the brain after partial hematoma removal, and recurrences in 59, 52, 15, 49, 19, and 2 patients, respectively. There were 2 deaths, without any procedure-related mortality. CONCLUSIONS: Endoscope was very effective and safe in the management of chronic subdural hematoma, especially in about 51% patients with solid clots, septations, and bridging vessels which could have been difficult to treat by conventional burr hole. It can avoid craniotomy in such patients. Good visualization and complete hematoma removal were possible with the help of an endoscope and brain retractor in about 27% of patients which could have been difficult with a rigid endoscope alone.

Hip Fracture in a Patient with Overlap Syndrome - Conundrums Involved in the Management - A Case Report.

Introduction: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative condition producing symptoms of varying severity depending on the extent and progression of the disease pathology most importantly respiratory insufficiency and pulmonary complications. Myasthenia gravis (MG) on the other hand is an autoimmune condition due to the pathology involving failure of neuromuscular transmission causing muscle weakness exacerbated by activity and involvement of the respiratory muscles leading to respiratory failure. Overlap syndrome is a condition wherein both motor neuron disease (MND) and MG are present in the same patient. The safety of using muscle-relaxing agents in patients with MG undergoing major surgical procedures has so far been assessed as insufficient. There have been many concerns regarding anesthetic management in relation to complications with respiratory function in patients with ALS, with regional anesthesia being considered slightly safer. Case Report: An 81-year-old female presented with a closed injury to her left hip, and she was diagnosed to have a left neck of femur fracture. She was also a known case of bulbar MND with an overlap syndrome of MG. She was hypertensive and controlled with regular medication. She was planned for a left hip bipolar arthroplasty. Anesthetic requirements and management of these patients require a high degree of expertise and anesthesia in patients undergoing surgery is prone to more complications and mortality. In addition, as the patient had an overlap of both MG and MND, more meticulous assessment and management strategies were necessary. Conclusion: The importance and purpose of this study are to highlight a case of overlap syndrome of MND and MG patients who sustained a left neck femur fracture and underwent bipolar arthroplasty highlighting the anesthetic considerations in the patient for the procedure. We concluded that the choice of mode of anesthesia needs to be individualized based on each patient's requirements after careful analysis of the risk-benefit ratio of general versus regional. Regional anesthesia was successfully administered for this patient.

Impact of accreditation on documentation and staff perception in the ophthalmology department of an Indian medical college.

Purpose: National Accreditation Board for Hospitals and Healthcare Providers operates the health-care accreditation program in India. Research on impact of accreditation on eye-care centers is scarce. This article was conceptualized to scientifically evaluate the changes in documentation brought about by accreditation and its effects on staff in the Ophthalmology Department of an Indian Medical College. Methods: This was conducted as a quasi-experimental study in four steps. First, a point-based evaluation of case sheets in both pre-accreditation and postaccreditation phase, along with statistical analysis of the results, was done. Step two involved analysis of quality indicators and patient safety indices in successive years from inception of data to post-accreditation phase. Step three comprised a survey of staff employing a validated tool, and finally, face-to-face semistructured interviews with designated authorities, including finance departmental head, completed the study. Results: A statistically significant difference was seen in scores achieved by the pre and postaccreditation case sheets, with the postphase case sheets achieving 15% increased scores over the prephase case sheets. Quality indicator indices displayed improvements post-accreditation. There was an accompanying increase in quantity of documentation. Financial data analysis showed increased expenditure for accreditation under multiple heads. Staff believed that accreditation led to increased workload but did not express decreased satisfaction and felt that accreditation was eventually beneficial. However, staff believed rewards for improving quality can be enhanced. Conclusion: Accreditation increases quality and quantity of documentation, and staff workload. Increased financial costs also ensue.Staff believe that accreditation improves quality, is beneficial, but desire enhanced rewards.

Lumboperitoneal Shunts - Patient Selection, Technique, and Complication Avoidance: An Experience of 426 Cases.

BACKGROUND: Lumboperitoneal shunt is a known procedure for communicating hydrocephalus. Being an extracranial procedure, it can also be utilized in normal-sized ventricles. OBJECTIVE: To report our experience of lumboperitoneal shunt done with a minimal follow-up of 12 months with an emphasis on patient selection, technique, and complication avoidance. METHODS: This was a retrospective analysis of patients who underwent LP shunt during October 2014-October 2019 at the authors' institute. Inclusion criteria were patients with communicating hydrocephalus due to tubercular meningitis, normal pressure hydrocephalus, idiopathic intracranial hypertension, and postoperative refractory cerebrospinal fluid leaks. Data were collected for demographics, Glasgow coma scale and Glasgow outcome scale, vision, gait, memory, urinary incontinence, failed attempts, and complications. RESULTS: A total of 426 patients underwent the LP shunt procedure. The commonest indication was tubercular meningitis followed by idiopathic intracranial hypertension and normal pressure hydrocephalus. Age ranged from 16 to 72 years. There were 255 male and 171 female patients. The mean follow-up was 41 ± 8 months. Overall, 301 patients (70.6%) had neurological improvement. Shunt-related complications occurred in 112 (26.29%) patients, of which shunt block was the commonest. Other complications were infection in 17 (3.9%) patients and extrusion in four (0.9%) patients. Transient postural headache was seen in 46 (10.7%) patients, which gradually improved. CONCLUSION: Lumboperitoneal shunt was found to be a safe and effective treatment in appropriately selected communicating hydrocephalus patients. A meticulous technique reduces the complication rate.

Efficacy of small-volume gastrografin videofluoroscopic screening for detecting pharyngeal leaks following total laryngectomy.

OBJECTIVES: Pharyngocutaneous fistulae are dreaded complications following total laryngectomy. This paper presents our experience using 3-5 ml gastrografin to detect pharyngeal leaks following total laryngectomy, and compares post-operative videofluoroscopy with clinical follow-up findings in the detection of pharyngocutaneous fistulae. METHODS: A retrospective case-control study was conducted of total laryngectomy patients. The control group (n = 85) was assessed clinically for development of pharyngocutaneous fistulae, while the study group (n = 52) underwent small-volume (3-5 ml) post-operative gastrografin videofluoroscopy. RESULTS: In the control group, 24 of 85 patients (28 per cent) developed pharyngocutaneous fistulae, with 6 requiring surgical correction. In the study group, 24 of 52 patients (46 per cent) had videofluoroscopy-detected pharyngeal leaks; 4 patients (8 per cent) developed pharyngocutaneous fistulae, but all cases resolved following non-surgical management. Patients who underwent videofluoroscopy had a significantly lower risk of developing pharyngocutaneous fistulae; sensitivity and specificity in the detection of pharyngocutaneous fistulae were 58 per cent and 100 per cent respectively. CONCLUSION: Small-volume gastrografin videofluoroscopy reliably identified small pharyngeal leaks. Routine use in total laryngectomy combined with withholding feeds in cases of early leaks may prevent the development of pharyngocutaneous fistulae.

Manipal diabetes coronary artery severity score.

AIMS: To develop a risk score, for identifying severe and complex CAD in patients with type 2 diabetes mellitus. METHODS: In this cross sectional study, 179 patients with type 2 diabetes mellitus undergoing coronary angiogram for the evaluation of suspected coronary artery disease (CAD) were recruited at a tertiary-care hospital. Patients were divided into developmental (n=124) and validation (n=55) cohorts. Biochemical and anthropometric parameters were analysed. Predictors of severe and complex CAD (SYNTAX Score>22) were identified by multiple logistic regression analysis. RESULTS: Insulin resistance>3.4 (OR: 21.26, 95% CI: 5.71-79.09), duration of diabetes>5years (OR: 13.50, 95% CI: 3.13-58.25), total cholesterol/HDL-C ratio>5 (OR: 2.75, 95% CI: 0.66-11.55) and waist circumference>96cm (OR: 5.08, 95% CI: 1.27-20.42) were independent predictors of severe and complex CAD, and Manipal Diabetes Coronary Artery Severity Score was developed. CONCLUSIONS: The prediction of severe and complex CAD was achieved with this simple score, and thus enabling effective identification of patients beforehand, who are not likely to be suitable for angioplasty.

Severity of coronary artery disease in type 2 diabetes mellitus: Does the timing matter?

AIM: The aim of our study was to compare the angiographic changes in 53 nondiabetic patients, 54 type 2 diabetic patients of less than 5 years of duration, 41 patients with 5-10 years of diabetes, and 27 with more than 10 years of diabetic duration. METHODS: In this cross-sectional study, 175 patients, who underwent coronary angiogram for the evaluation of the coronary artery disease (CAD), were recruited. Based on the angiographic findings, syntax score, vessel score, and coronary collaterals grading were analyzed. The biochemical analysis was done by using the auto analyzer. RESULTS: A significant increase in the mean syntax score (p=0.019), vessel score (p=0.007), and coronary collateral grade (p=0.008) was observed in the patients with 5-10 years of diabetes when compared to those with less than 5 years of diabetic duration. There was no significant difference in the mean syntax score (p=0.979), vessel score (p=0.299), and collateral grade (p=0.842) between the patients with 5-10 years and more than 10 years of diabetes. The difference in the mean syntax score (p=0.791), vessel score (p=0.098), and collateral grade (p=0.661) between the nondiabetic and the patients with less than 5 years of diabetes was not significant. CONCLUSION: A significant structural change in the coronary arteries was found among the patients with 5-10 years of diabetes.

Incidence of fatal snake bite in Loni, Maharashtra: An autopsy based retrospective study (2004-2014).

Snake bite is a major public health problem specially in a rural region where agricultural work is the major source of employment. A retrospective study was undertaken of all cases of deaths due to snake bite autopsied at the Mortuary of Pravara Rural Hospital, Loni a rural area in Western Maharashtra over a period of 10 years from January 2004 to December 2014. Data of the study was gathered from autopsy reports and hospital records. The cases represented approximately 2.13% (54) of the total 2539 medico legal autopsies conducted during the study period. Most of the deaths (42.60%) occurred in the age group of 11-30 years and both males and females were affected in almost equal proportions. There was a marked increase in the number of cases in monsoon season (59.26%). The lower extremity was the most frequently involved site of bite (62.96%). Snakes were identified in 43 cases (79.63%) and among the identified cases the most common culprit was Viper amounting to 29.63% of cases followed by Krait causing 24.07% of the deaths. The findings in our study reflects the necessity of educating the rural community regarding the hazards of snake bite, importance of early medical attention and to avoid wasting vital time being engaged by traditional healers.

Infectious complications and mortality in an American acute care surgical service.

BACKGROUND: Acute care surgery (ACS) services have evolved in an effort to provide 24-h surgical services for a wide array of general surgical emergencies. The formation of ACS services has been shown to improve outcomes and lead to more expeditious care. Despite the advances of ACS, the etiology and timing of patient mortality has yet to be described. We hypothesized that infectious complications occur more frequently in ACS patients that die during their hospitalization. METHODS: A retrospective review of a local ACS service (non-trauma) registry was conducted. Demographic variables, admission and discharge data, and ICD-9 codes were collected. ICD-9 codes were used to identify patients with sepsis, shock, GI perforation, peritonitis, and other hospital acquired infections (urinary tract, bloodstream, and ventilator-associated pneumonias). Univariate and multivariate logistic regression analysis was performed to model the outcome of death. RESULTS: 1,329 patients were analyzed. 53 % were male with the mean age of 52 years and an average length of stay of 13 days. 106 (8 %) died while in the hospital. Of the patients who died, 34 (32 %) died within 7 days of admission. The majority of mortalities (56 %) occurred after hospital day 14. In ACS patients that died, there were significantly higher rates of sepsis, shock, peritonitis, urinary tract infections, and VAP. After adjustment; age, sepsis on admission, and shock on admission were associated with greater odds of death. CONCLUSION: ACS patients with sepsis and shock have higher mortality rate than those patients without. The majority of ACS patient deaths occurred after hospital day 14. Further investigation and continued focus on preventing and rapidly treating infectious complications as they arise is warranted.

Factors associated with no apparent coronary artery disease in patients with type 2 diabetes mellitus for more than 10 years of duration: a case control study.

BACKGROUND: Type 2 diabetes mellitus is an important risk factor in the development of coronary artery disease (CAD) and is often associated with severe disease. However, this risk is not uniform, some patients remain free of CAD even after many years of treatment for diabetes. The present study was aimed to identify the factors that are associated with a favorable CAD profile. METHODS: A case-control study of 76 patients with type 2 diabetes mellitus who were on treatment for more than 10 years duration and undergoing a coronary angiogram for the evaluation of clinically suspected CAD at a tertiary care hospital were recruited for the study. The presence and absence of significant CAD was determined after a coronary angiogram. Clinical history, and anthropometric and biochemical parameters were analyzed. Insulin resistance was determined by the Homeostasis Model Assessment. Multiple logistic regressions were done to find out the factors associated for a favorable CAD profile. RESULTS: The difference in HOMA-IR (2.37 ± 0.69 VS 3.77 ± 1.64, p < 0.001) and urine microalbumin (24.15 ± 32.16 VS 82.72 ± 117.70, p = 0.004) were found to be statistically significant among those who did not have CAD when compared to those who had CAD. The difference in lipid profile, HbA1C, fasting blood sugar, BMI, waist hip ratio, waist and hip circumference was not significant. The adjusted odds ratio for insulin resistance less than 2.5 (OR 9.09, 95 % CI 1.91-41.83, p = 0.005), females (OR 7.91, 95% CI 1.55-40.38, p = 0.013) and microalbumin <20 mg/l (OR 4.57, 95% CI 1.17-17.85, p = 0.029) were independently associated with normal coronaries. The adjusted odds ratio for lipid profile, BMI, blood pressure and HbA1C were not significant. CONCLUSIONS: HOMA-IR less than 2.5, microalbuminuria less than 20 mg/l and females are the factors appear to be associated with no apparent CAD.

Outpatient Use of Focused Cardiac Ultrasound to Assess the Inferior Vena Cava in Patients With Heart Failure.

Accurate assessment of volume status is critical in the management of patients with heart failure (HF). We studied the utility of a pocket-sized ultrasound device in an outpatient cardiology clinic as a tool to guide volume assessment. Inferior vena cava (IVC) size and collapsibility were assessed in 95 patients by residents briefly trained in focused cardiac ultrasound (FCU). Cardiologist assessment of volume status and changes in diuretic medication were also recorded. Patients were followed for occurrence of 30-day events. There was a 94% success rate of obtaining IVC size and collapsibility, and agreement between visual and calculated IVC parameters was excellent. Most patients were euvolemic by both FCU IVC and clinical bedside assessment (51%) and had no change in diuretic dose. Thirty-two percent had discrepant FCU IVC and clinical volume assessments. In clinically hypervolemic patients, the FCU evaluation of the IVC suggested that the wrong diuretic management plan might have been made 46% of the time. At 30 days, 14 events occurred. The incidence of events increased significantly with FCU IVC imaging categorization, from 11% to 23% to 36% in patients with normal, intermediate, and plethoric IVCs. By comparison, when grouped in a binary manner, there was no significant difference in event rates for patients who were deemed to be clinically volume overloaded. Assessment of volume status in an outpatient cardiology clinic using FCU imaging of the IVC is feasible in a high percentage of patients. A group of patients were identified with volume status discordant between FCU IVC and routine clinic assessment, suggesting that IVC parameters may provide a valuable supplement to the in-office physical examination.

Hepatic metastasis arising from diverse primary pathologies diagnosed on 99mTc-Methylene diphosphonate bone scan.

We are presenting two cases that illustrate nonosseous localization of 99mTc-Methylene diphosphonate (MDP) in hepatic metastases arising from varied primary pathology and review of the literature. This series emphasizes the evidence of MDP localization in hepatic metastases arising from adenocarcinoma of rectum and infiltrating duct cell carcinoma of the breast.

Comparative study of lipid composition of two halotolerant alga, Dunaliella bardawil and Dunaliella salina.

The composition of polar, neutral and glycolipid fractions of two halotolerant algae, Dunaliella salina and Dunaliella bardawil, which are exclusively used for the production of beta-carotene was determined in modified medium. In D. salina the glycolipid fraction accounted to 28%, in comparison with 40% of D. bardawil. However, in D. salina the polar lipid was 42% compared with D. bardawil at 24%. The glycolipid fraction of D. bardawil was rich in linolenic acid (81%). In both the species we could find elongation in the fatty acids from C(16) to C(20) to C(22) and the percentage was higher than the earlier reports (>3%). The polar lipid fraction was composed of (in descending order) phosphatidyl glycerol, phosphatidic acid, phosphatidic ethanolamine, phosphatidyl choline and phosphatidyl glycerol and the neutral lipid fraction, which was rich in monoglycerides and diglycerides and diacylglycero-trimethylhomoserine.

Specific pretreatments reduce curing period of vanilla (Vanilla planifolia) beans.

With the aiming of reducing the curing period, effects of pretreatments on flavor formation in vanilla beans during accelerated curing at 38 degrees C for 40 days were studied. Moisture loss, change in texture, levels of flavoring compounds, and activities of relevant enzymes were compared among various pretreatments as well as the commercial sample. Use of naphthalene acetic acid (NAA; 5 mg/L) or Ethrel (1%) with blanching pretreatment resulted in 3-fold higher vanillin on the 10th day. Other flavoring compounds-vanillic acid, p-hydroxybenzoic acid, and p-hydroxybenzaldehyde-fluctuated greatly, showing no correlation with the pretreatments. Scarification of beans resulted in nearly 4- and 3.6-fold higher vanillin formations on the 10th day in NAA- and Ethrel-treated beans, respectively, as compared to control with a significant change in texture. When activities of major relevant enzymes were followed, addition of NAA or Ethrel helped to retain higher levels of cellulase throughout the curing period and higher levels of beta-glucosidase on the 20th day that correlated with higher vanillin content during curing and subsequent periods. Peroxidase, being highest throughout, did not correlate with the change in levels of major flavoring compounds. The pretreatment methods of the present study may find importance for realizing higher flavor formation in a shorter period because the major quality parameters were found to be comparable to those of a commercial sample.

Impact of an easily reducible disulfide bond on the oxidative folding rate of multi-disulfide-containing proteins.

The burial of native disulfide bonds, formed within stable structure in the regeneration of multi-disulfide-containing proteins from their fully reduced states, is a key step in the folding process, as the burial greatly accelerates the oxidative folding rate of the protein by sequestering the native disulfide bonds from thiol-disulfide exchange reactions. Nevertheless, several proteins retain solvent-exposed disulfide bonds in their native structures. Here, we have examined the impact of an easily reducible native disulfide bond on the oxidative folding rate of a protein. Our studies reveal that the susceptibility of the (40-95) disulfide bond of Y92G bovine pancreatic ribonuclease A (RNase A) to reduction results in a reduced rate of oxidative regeneration, compared with wild-type RNase A. In the native state of RNase A, Tyr 92 lies atop its (40-95) disulfide bond, effectively shielding this bond from the reducing agent, thereby promoting protein oxidative regeneration. Our work sheds light on the unique contribution of a local structural element in promoting the oxidative folding of a multi-disulfide-containing protein.

Utilization of glycerol as carbon source on the growth, pigment and lipid production in Spirulina platensis.

The ability of the cyanobacterium Spirulina platensis to utilize glycerol as the carbon source was investigated. In this work, we report on some physiological parameters that characterize the adaptive response of Spirulina platensis for the utilization of glycerol as the carbon source. A marked decrease was observed in the pigments Chlorophyll a (Chl a) and phycocyanin content of Spirulina platensis grown on glycerol medium when compared to the control. The lipid content in the glycerol-grown groups was comparable with the control, but variations were observed in the fatty acid profile of the total lipid mainly in the level of monoenes and polyenes. There was an increase in the gamma-linolenic acid (GLA) in the Neutral lipid (NL) fraction.

Food-grade chemical and biological agents permeabilize red beet hairy roots, assisting the release of betalaines.

Hairy root cultures of red beet, Beta vulgaris L., were permeabilized under the functions of food-grade chemical and biological agents cetyl trimethylammonium bromide (CTAB), Triton X-100, Tween-80, Lactobacillus helveticus, Saccharomyces cereviseae, and Candida utilis, as well as cell fractions of L. helveticus, for the recovery of betalaines with or without oxygen stress. Tween-80 (0.15%), Triton X-100 (0.2%), and CTAB (0.05%), in combination with oxygen stress, released 45%, 70%, and 90% pigment into the medium, respectively, with significantly lesser levels in agitated cultures receiving similar treatments. The release was rapid (1 h) in CTAB treatment with a much slower release in Tween-80. CTAB (0.002%) was found to be also useful in effluxing betalaines (80%) from hairy roots grown in a bubble column reactor. Viability of permeabilized hairy roots, tested on agar medium, was not affected by any level of CTAB treatment and was significantly retarded at higher levels of Triton X-100 and Tween-80. An altogether new approach of pigment release using biological agents such as live cells of food-grade microbes was used where C. utilis, L. helveticus, and S. cereviseae released 60%, 85%, and 54% betalaines, respectively, in 24 h, though lower level treatments also released similar levels of pigment by 48 h. Dried whole cell powder of L. helveticus, its total insoluble carbohydrate, and free lipid fractions released 10%, 0%, and 85% pigment, respectively. An extended study with a bubble column reactor using the free lipid fraction of L. helveticus showed 50% and 84% pigment release in 8 and 12 h, respectively, exhibiting good viability when plated on agar medium. Even in the bioreactor, replenishment of medium 8 h after treatment with free lipid of L. helveticus allowed regrowth of hairy roots. The high level of pigment release recorded here, using CTAB or lipid of L. helveticus, appears useful for developing processes for in situ recovery of betalaines. The live microbes, applicable only for batch cultures, are expected to impart improved sensory/nutraceutical effects to the recovered pigment and hence may add value to the product receiving the red beet pigment thus produced.

Antioxidant activity of the anthocyanin from carrot (Daucus carota) callus culture.

Antioxidant properties of water-soluble anthocyanin obtained from the carrot (Daucus carota) callus cultures were evaluated by the estimation of the amount of hydroperoxide formed by the autoxidation of linolenic acid at pH 2, 4 and 7. A major anthocyanin, cyanidin-3-lathyroside, was isolated and the antioxidant property was compared with malvidin, peonidin delphinidin and alpha-tocopherol. The malvidin, peonidin and delphinidin were obtained from grapes, Chinese mustard and egg-plant. At pH 2 and 4 the anthocyanin was better than malvidin and peonidin. The results indicate that anthocyanin obtained from carrot showed an antioxidation activity stronger than malvidin, peonidin and alpha-tocopherol, and weaker than delpinidin at pH 2, 4 and 7 by the linolenic acid auto-oxidation system.