Decreased scene-selective activity within the posterior intraparietal cortex in amblyopic adults.

Amblyopia is a developmental disorder associated with reduced performance in visually guided tasks, including binocular navigation within natural environments. To help understand the underlying neurological disorder, we used fMRI to test the impact of amblyopia on the functional organization of scene-selective cortical areas, including the posterior intraparietal gyrus scene-selective (PIGS) area, a recently discovered region that responds selectively to ego-motion within naturalistic environments (Kennedy et al., 2024). Nineteen amblyopic adults (10 female) and thirty age-matched controls (12 female) participated in this study. Amblyopic participants spanned a wide range of amblyopia severity, based on their interocular visual acuity difference and stereoacuity. The visual function questionnaire (VFQ-39) was used to assess the participants' perception of their visual capabilities. Compared to controls, we found weaker scene-selective activity within the PIGS area in amblyopic individuals. By contrast, the level of scene-selective activity across the occipital place area (OPA), parahippocampal place area (PPA), and retrosplenial cortex (RSC)) remained comparable between amblyopic and control participants. The subjects' scores on "general vision" (VFQ-39 subscale) correlated with the level of scene-selective activity in PIGS. These results provide novel and direct evidence for amblyopia-related changes in scene-processing networks, thus enabling future studies to potentially link these changes across the spectrum of documented disabilities in amblyopia.

A previously undescribed scene-selective site is the key to encoding ego-motion in naturalistic environments.

Current models of scene processing in the human brain include three scene-selective areas: the parahippocampal place area (or the temporal place areas), the restrosplenial cortex (or the medial place area), and the transverse occipital sulcus (or the occipital place area). Here, we challenged this model by showing that at least one other scene-selective site can also be detected within the human posterior intraparietal gyrus. Despite the smaller size of this site compared to the other scene-selective areas, the posterior intraparietal gyrus scene-selective (PIGS) site was detected consistently in a large pool of subjects (n = 59; 33 females). The reproducibility of this finding was tested based on multiple criteria, including comparing the results across sessions, utilizing different scanners (3T and 7T) and stimulus sets. Furthermore, we found that this site (but not the other three scene-selective areas) is significantly sensitive to ego-motion in scenes, thus distinguishing the role of PIGS in scene perception relative to other scene-selective areas. These results highlight the importance of including finer scale scene-selective sites in models of scene processing - a crucial step toward a more comprehensive understanding of how scenes are encoded under dynamic conditions.

Using high-resolution functional MRI to differentiate impacts of strabismic and anisometropic amblyopia on evoked ocular dominance activity in humans.

We employed high-resolution functional MRI (fMRI) to distinguish the impacts of anisometropia and strabismus (the two most frequent causes of amblyopia) on the evoked ocular dominance (OD) response. Sixteen amblyopic participants (8 females), comprising 8 individuals with strabismus, 7 with anisometropia, 1 with deprivational amblyopia, along with 8 individuals with normal visual acuity (1 female), participated in this study for whom, we measured the difference between the response to stimulation of the two eyes, across early visual areas (V1-V4). In controls, as expected from the organization of OD columns, the evoked OD response formed a striped pattern that was mostly confined to V1. Compared to controls, the OD response in amblyopic participants formed larger fused patches that extended into downstream visual areas. Moreover, both anisometropic and strabismic participants showed stronger OD responses in V1, as well as in downstream visual areas V2-V4. Although this increase was most pronounced in V1, the correlation between the OD response level and the interocular visual acuity difference (measured behaviorally) was stronger in higher-level visual areas (V2-V4). Beyond these common effects, and despite similar densities of amblyopia between the anisometropic and strabismic participants, we found a greater increase in the size of V1 portion that responded preferentially to fellow eye stimulation in anisometropic compared to strabismic individuals. We also found a greater difference between the amplitudes of the response to binocular stimulation, in those regions that responded preferentially to the fellow vs. amblyopic eye, in anisometropic compared to strabismic subjects. In contrast, strabismic subjects demonstrated increased correlation between the OD responses evoked within V1 superficial and deep cortical depths, whereas anisometropic subjects did not. These results provide some of the first direct functional evidence for distinct impacts of strabismus and anisometropia on the mesoscale functional organization of the human visual system, thus extending what was inferred previously about amblyopia from animal models.

A previously undescribed scene-selective site is the key to encoding ego-motion in naturalistic environments.

Current models of scene processing in the human brain include three scene-selective areas: the Parahippocampal Place Area (or the temporal place areas; PPA/TPA), the restrosplenial cortex (or the medial place area; RSC/MPA) and the transverse occipital sulcus (or the occipital place area; TOS/OPA). Here, we challenged this model by showing that at least one other scene-selective site can also be detected within the human posterior intraparietal gyrus. Despite the smaller size of this site compared to the other scene-selective areas, the posterior intraparietal gyrus scene-selective (PIGS) site was detected consistently in a large pool of subjects (n=59; 33 females). The reproducibility of this finding was tested based on multiple criteria, including comparing the results across sessions, utilizing different scanners (3T and 7T) and stimulus sets. Furthermore, we found that this site (but not the other three scene-selective areas) is significantly sensitive to ego-motion in scenes, thus distinguishing the role of PIGS in scene perception relative to other scene-selective areas. These results highlight the importance of including finer scale scene-selective sites in models of scene processing - a crucial step toward a more comprehensive understanding of how scenes are encoded under dynamic conditions.

First Report of 'Candidatus Phytoplasma aurantifolia' Related Strain (16SrII-D) Associated with Stunting, Little Leaf and Phyllody Disease of Pearl Millet from South India.

Pearl millet [Pennisetum glaucum (L).R.Br.] also known as bajra, is one of the oldest millets and is cultivated in dry regions of arid and semi-arid tropics where no other cereal can be successfully grown. Pearl millet cultivation in India accounts for about two-thirds of millet production and is the fourth most cultivated food crop after rice, wheat and maize in India (Reddy et al. 2021a). In February 2021, the typical symptoms of stunting, phyllody and little leaf were observed after 25-30 days after sowing pearl millet seeds at Agricultural Research Station in Perumallapalle, Tirupati, India (Fig.1 A-C). The disease incidence was recorded up to 20% in the sampling regions. Total DNA was extracted from two symptomatic and two asymptomatic plant samples using CTAB DNA extraction method (Murray and Thompson, 1980). The extracted DNA was amplified in direct PCR and nested PCR assay using phytoplasma 16S rRNA universal primer pairs P1/P7 and R16F2n/R16R2 (Gundersen and Lee.1996) and secA gene with secAfor1/SecArev3 and SecAfor2/SecArev3 primer pairs (Hodgetts et al. 2008). 16SrRNA (1.25 kb) and secA (600 bp) gene amplicons were obtained from two symptomatic samples by nested PCR. No amplicons were produced with DNA from healthy leaf samples. Nested PCR amplified products (1.25 kb and 600 bp) from the symptomatic samples corresponding to the F2nR2 region of 16S rRNA and secA were directly sequenced at automated DNA sequencing facility (Eurofin Genomics India Pvt., Ltd Bangalore) and sequence data was deposited to NCBI GenBank with accession number ON005559 and ON067810. BLAST analysis revealed that pearl millet phytoplasma strain shared 100% sequence identity in 16Sr RNA and secA genes to 'Canditatus Phytoplasma aurantifolia' related strains (Acc. Nos. OM616883 and MT952965) from India. The subgroup was identified as 16SrII-D using the iPhyClassifier based on the virtual RFLP pattern derived from the query 16S rDNA F2nR2 fragment (Zhao et al. 2009). The virtual RFLP pattern is similar to the reference pattern of 16SrII-D (Y10096) with similarity coefficient 1.00. Phylogenetic analysis of 16S rRNA and secA gene sequences using MEGA version 7.0 revealed that the pearl millet phytoplasma strain clustered with 'Ca. P. aurantifolia' isolates of 16SrII-D subgroup. (Fig.1D-E) Earlier, one of 16SrI-B-phytoplasma strain (HM 134245) associated with green ear disease of pearl millet was reported in North India (Kumar et al. 2010). In this study, we reported the association of 16SrII-D subgroup phytoplasma with little leaves and witches'-broom disease of pearl millet in South India. Phytoplasmas belonging to the 16SrII-D subgroup have a wide range of hosts, including the agricultural and horticultural crops (Reddy et al., 2021b). Hence, this is the first report of 'Ca. P aurantifolia' infection in bajra in South India. The increase in the spread of 16SrII-D sub group phytoplasma diseases and the expansion of the host range strongly suggest further studies on the epidemiology of the dynamic dissemination of this disease in India.

Video-assisted teaching versus traditional didactic lecture in undergraduate psychiatry teaching.

OBJECTIVES: The objectives of this study are as follows: (1) To compare video-assisted teaching versus didactic lectures using the pretest and posttest. (2) To compare the feedback on the two teaching methods using a teaching feedback form. MATERIALS AND METHODS: Two consecutive batches of 22 and 20 students, respectively, of the 3rd year medical undergraduate students posted to the department of psychiatry were included for the study. The first batch underwent video-assisted schizophrenia class and didactic lecture in bipolar disorder (BPAD). A crossover of the topics was done. The students underwent pretest and posttest for each topic using the same set of topic-specific validated multiple choice questions and also filled a prevalidated teaching feedback form for each class. RESULTS: Difference between pre- and post-test scores after all classes was significant, indicating effective gain of knowledge by both methods. Feedback analysis indicated that most students favored video-assisted teaching (total mean feedback score - 61.99) compared to the conventional method (total mean feedback score - 60.58). Increase in mean feedback scores indicates the students' preference. CONCLUSION: Both didactic and video-assisted lectures were effective in terms of knowledge gained and students' feedback. Using video assistance as a complement to lectures and not to replace the traditional methods is the way forward.

Auditory function and quality of life in patients receiving cisplatin chemotherapy in head and neck cancer: A case series follow-up study.

BACKGROUND: Cisplatin is one of the anticancer drugs used for head and neck cancers. Although some studies have shown that cisplatin can cause ototoxicity, periodic audiometric assessments have not been extensively studied in the Indian rural population. Hence, this study has been undertaken to evaluate the effects of cisplatin on hearing. MATERIALS AND METHODS: Fifty-nine patients with squamous cell carcinomas of head and neck, who received cisplatin chemotherapy, were recruited. Serum creatinine, blood urea, serum proteins, and audiometry were assessed before and after the first, second, and third chemotherapy cycle. The cochleotoxic effect of cisplatin was assessed by pure tone audiometry. Hearing loss was graded accordingly. All patients were administered a quality of life questionnaire at baseline and at the end of the third cycle. RESULTS: Hearing loss was observed in 12 patients at speech frequencies and those at higher frequencies were 12 (4000 Hz), 18 (6000 Hz), and 28 (8000 Hz). The hearing loss was symmetrical, sensorineural, and showed a strong correlation with the low serum albumin levels at the end of the third cycle. Dizziness was seen in eight patients, at the end of the study. The commonly observed adverse effects were nausea, vomiting, hair loss, fatigue, and tinnitus. CONCLUSION: The studies have shown hearing loss in higher frequencies, but in our study, we have observed hearing loss at speech frequency in 22.2% of patients receiving cisplatin, who also had low serum albumin levels. Periodic audiometric monitoring and serum albumin level may be helpful to provide timely intervention to prevent further hearing loss and deterioration in the quality of life.

Topical Olopatadine Hydrochloride versus Ketotifen Fumarate for Allergic Conjunctivitis.

PURPOSE: Allergic conjunctivitis (AC) is associated with itching, redness, tearing, pain, and burning sensation in the eyes. The inflammatory process is caused by the mechanism of immediate hypersensitivity due to direct contact with the allergen. This process triggers mast cells in the conjunctiva to activate and release mediators. The purpose of this study was to compare topical olopatadine and ketotifen in terms of effectiveness and safety for the management of AC. METHODS: Patients clinically diagnosed with AC were randomized into two groups of 60 patients each and received either topical olopatadine HCl 0.1% or ketotifen fumarate 0.025%. They were followed up on the 4th, 15th, and 30th days to evaluate symptoms, signs, and quality of life (QOL) scoring. RESULTS: There were a total of 120 patients (67 men and 53 women) with a mean age of 36.35 ± 11 years. Compared to baseline, scores of itching, tearing, redness, eyelid swelling, chemosis and papillae addition of all the individual scores mentioned above and QOL scores reduced significantly (P = 0.001) by the 4th and 15th days of olopatadine and ketotifen application. Compared with ketotifen, olopatadine significantly reduced itching, tearing, hyperemia, and total AC scores by the 4th day (P = 0.001) and conjunctival papillae by the 15th day (P = 0.001). Adverse reactions were reported in 10% and 18% of patients treated with olopatadine and ketotifen, respectively. CONCLUSION: Compared to ketotifen, olopatadine provided quicker relief of symptoms, and improved symptoms of AC and QOL, with fewer side effects.

Decrease in Anti-HBs Antibodies over Time in Medical Students and Healthcare Workers after Hepatitis B Vaccination.

BACKGROUND: Hepatitis B is one of the most important occupational hazards among healthcare workers (HCWs). This study aimed to measure the anti-HBs titres among the medical students and HCWs vaccinated against hepatitis B virus and to determine the association between anti-HBs levels and time since vaccination. MATERIALS AND METHODS: In this cross-sectional study, medical students and healthcare workers who had received all three doses of hepatitis B vaccination and completed at least six months after vaccination since the last dose were included. 3 ml blood was collected from subjects (n = 340) and anti-HBs titre was estimated using ELISA. RESULTS: A total of 340/400 subjects were aged between 18 and 60 years; 204 were females and 136 males. The median and interquartile range for time since vaccination were 5 and 5 years, respectively. Duration since vaccination was ≤5 years in 223 (65.5%), 6-10 years in 84 (24.7%), and >10 years in 33 (9.70%); among them, antibody titres were >10 mIU/ml in 94.1%, 79.7%, and 72.7% subjects, respectively. There was significant decline in antibody titres as duration of postvaccination increased. CONCLUSION: The proportion of subjects who were unprotected after 5 and 10 years after vaccination were 20% and 27%, respectively. The need for a booster dose can be made mandatory at least for healthcare professionals.

Serum creatine phosphokinase as predictor of intermediate syndrome in organophosphorus poisoning.

BACKGROUND: Organophosphorus (OP) compounds are commonly used pesticides. In OP poisoning, intermediate syndrome (IMS) manifests between the end of the acute cholinergic crisis and delayed neuropathy. Respiratory paralysis in IMS, if identified early can reduce the need for ventilator support, morbidity, and mortality. Serum creatine phosphokinase (CPK) is elevated in IMS. The objectives of our study were to measure serum CPK level, correlate CPK levels with severity of poisoning and estimate atropine dose used. MATERIALS AND METHODS: A prospective, observational study was conducted for 1-year. Patients diagnosed with OP poisoning were included. Demographic characteristics, type of poison, time since poisoning, Peradeniya Organophosphorus Poisoning (POP) score, serum pseudocholinesterase, CPK levels, atropine dose, and outcome of treatment were documented. RESULTS: Seventy-five patients were recruited of which 57% and 43% were males and females, respectively, with a mean age of 31.48 ± 11.76 years. The most common OP compound was chlorpyriphos followed by triazophos and methylparathion. The time required to reach hospital was 181.26 ± 89.53 min. About 73.3% and 26.7% of patients had mild and moderate poisoning, respectively, as per POP scale. Pseudocholinesterase level was 364 (205-2168) IU. The amount of atropine used was 190.66 ± 78.83 mg. Serial serum CPK values were 279.72 ± 350.21 IU, 389.78 ± 376.33 IU and 163.13 ± 155.15 IU at admission, 48 h, and 96 h after admission, respectively. A weak positive correlation between serum CPK levels and severity of poisoning (r = 0.352) was observed. All patients recovered completely within 10.69 ± 5.57 days. Three patients developed IMS, and their serial CPK levels were 1837.33 ± 243.19 IU/L, 1935 ± 97.41 IU/L, and 714.66 ± 394.82 IU/L; and recovered in 17 ± 5.6 days. CONCLUSION: Increased serum CPK levels at 48 h after poisoning was observed in all the patients, but three patients had more than 1500 IU/L, who manifested with IMS. Early diagnosis of IMS by serial estimation of CPK may help in timely intervention and reduce further life-threatening complications.

Papaya extract to treat dengue: a novel therapeutic option?

Dengue is a viral disease that today affects a vast number of people in over 125 countries and is responsible for a sizable number of deaths. In the absence of an effective antiviral drug to treat the disease, various treatments are being investigated. Studies have indicated that the juice of the leaves of the Carica papaya plant from the family Caricaceae could help to increase the platelet levels in these patients. This review describes some of the published studies on this topic. The search was done independently by the two authors using PubMed, Google and the library database and included relevant articles of the last 10 years. A total of 7 studies were included in this review, which were one animal study, one case report, three case series and two randomized controlled trials. Although many of the studies and case reports published in literature lack adequate information, some of the studies do raise the possibility that this treatment could be an important option in the future. Further large-scale studies could establish the usefulness or ineffectiveness of this natural product in the treatment of dengue.

Regadenoson.

Single-photon emission computerized tomography for myocardial perfusion imaging (MPI) is a non-invasive technique. MPI is performed by subjecting the patient to exercise or by using a pharmacological stress agent. Regadenoson is a selective A 2A adenosine receptor agonist used when MPI with exercise is contraindicated. It binds to the A 2A receptor and stimulates adenylate cyclase, resulting in increased cAMP, which phosphorylates protein kinase A thereby opening the ATP-dependant potassium channels leading to hyperpolarization in the coronary vascular smooth muscle. After a single bolus dose of regadenoson 400 µg, a peak plasma concentration (C max) of 13.6 ng/mL is attained in 1-4 min, with a terminal half-life of 2 h. It has a quick onset, short duration sufficient enough for hyperemic response, with comparable efficacy to adenosine, but with fewer side-effects. The adverse effects of this drug are dyspnea, headache, flushing, chest pain and atrioventricular block. Regadenoson is used for MPI in patients with co-morbid conditions like mild-to-moderate reactive airway disease, obstructive lung disease and renal impairment.

Effect of heparin and low-molecular weight heparin on serum potassium and sodium levels.

INTRODUCTION: To study the effects of heparin and low-molecular weight heparin (LMWH) on potassium and sodium levels in patients with cardiovascular diseases (CVDs) and stroke. MATERIALS AND METHODS: Sixty patients were recruited with 30 patients each receiving heparin and enoxaparin. Patients with CVD and stroke receiving heparin and LMWH were compared for their demographic profile and laboratory data, and this was analyzed by descriptive statistics. Risk factors associated with the development of hyperkalemia were analyzed using multiple logistic regression model. RESULTS: There was an increase in potassium levels and decrease in sodium levels compared with baseline in both the groups. The difference between the groups with respect to sodium and potassium levels was not statistically significant. On analysis, the risk factors for development of hyperkalemia were baseline potassium levels, serum creatinine, and creatinine clearance. The change in sodium and potassium levels on the fifth day of therapy was increased with LMWH compared with heparin, although not statistically significant. CONCLUSIONS: The clinician should anticipate hyperkalemia especially in patients with renal impairment receiving these drugs.

Analysis of different types of poisoning in a tertiary care hospital in rural South India.

The global problem of acute poisoning has steadily increased over the past few years. It is an important cause of morbidity and mortality in developing countries. Better preventive and management strategies can be developed if the incidence and pattern of acute poisoning is known. The study aims at analyzing the pattern, cause and mortality rate of poisoning. The study was conducted in a rural area in South India. This retrospective study was conducted from January 2003-December 2003. The data was analysed using descriptive statistics. Out of the 225 cases 139 were males and 86 females. Poisoning was common in the age group of 21-30 years which was 84 cases and 11-20 years was 73 cases. The poisons consumed were as follows: Organophosphorous 135 cases, aluminum and zinc phosphide 50 cases, phenobarbitone 18 cases, benzodiazepines 7 cases, paracetamol 2 cases, miscellaneous 13 cases. 94% were suicides and 6% accidental. Mortality rate was 12.8%. Establishment of strict policies against the sale and availability of pesticides and over the counter drugs is an effective way to control organophosphorous and drug poisoning.

A comparative study of nebivolol and (S) atenolol on blood pressure and heart rate on essential hypertensive patients.

OBJECTIVES: To study the effect of nebivolol 5 mg once daily versus (S)-atenolol 25 mg once daily in patients with essential hypertension. MATERIALS AND METHODS: A prospective study was conducted at RLJH and Research Centre which included 30 patients in each group with essential hypertension. The sex, age, presenting illness, and family history of the patients were recorded. Investigations such as blood sugar, urine analysis, kidney function test, lipid profile, and ECG were performed before starting the treatment. Any adverse effects during the treatment were noted. Blood pressure and heart rate were recorded at baseline and during follow-up. One group received nebivolol 5 mg once daily and other group (S)atenolol 25 mg once daily. Patients were followed-up every 15 days for 3 months. RESULTS: Nebivolol group had 18 males and 12 females with mean age 50.6 ± 9.5 years, (S)-atenolol had 16 males and 14 females with mean age 54.4 ± 9 years. Patients receiving nebivolol and (S)-atenolol showed a significant fall (P <·0001) in systolic (SBP), diastolic blood pressure (DBP), and heart rate at the end of first, second, and third month when compared to baseline. The difference in fall in SBP and DBP was insignificant between the groups, but fall in heart rate was significant (P <·0001). Adverse effects such as headache, dizziness, and fatigue were reported with both drugs. CONCLUSION: Reduction of blood pressure with nebivolol and (S)atenolol was similar, but fall in blood pressure from baseline was highly significant in both groups.

Ondansetron induced fatal ventricular tachycardia.

Ondansetron is a serotonin receptor antagonist used widely in the prophylaxis and treatment of postoperative nausea and vomiting (PONV) and vomiting associated with cancer chemotherapy. The common side effects of ondansetron are fever, malaise, diarrhoea, constipation, and allergic reactions. Extra-pyramidal reactions are rare and cardiovascular side effects are even rarer. Even though its clinical safety has been established in a large number of studies, its adverse effects have been reported and these include cardiovascular events like acute myocardial ischemia and arrhythmias in adults.([1]) Studies of its adverse effects in children are few. We report a rare adverse effect of ondansetron in a 14-year-old girl, presenting as ventricular tachycardia.