COVID-19 Stroke Apical Lung Examination Study 2: a national prospective CTA biomarker study of the lung apices, in patients presenting with suspected acute stroke (COVID SALES 2)

BACKGROUND

Apical ground-glass opacification (GGO) identified on CT angiography (CTA) performed for suspected acute stroke was developed in 2020 as a coronavirus-disease-2019 (COVID-19) diagnostic and prognostic biomarker in a retrospective study during the first wave of COVID-19.

OBJECTIVE

To prospectively validate whether GGO on CTA performed for suspected acute stroke is a reliable COVID-19 diagnostic and prognostic biomarker and whether it is reliable for COVID-19 vaccinated patients.

METHODS

In this prospective, pragmatic, national, multi-center validation study performed at 13 sites, we captured study data consecutively in patients undergoing CTA for suspected acute stroke from January-March 2021. Demographic and clinical features associated with stroke and COVID-19 were incorporated. The primary outcome was the likelihood of reverse-transcriptase-polymerase-chain-reaction swab-test-confirmed COVID-19 using the GGO biomarker. Secondary outcomes investigated were functional status at discharge and survival analyses at 30 and 90 days. Univariate and multivariable statistical analyses were employed.

RESULTS

CTAs from 1,111 patients were analyzed, with apical GGO identified in 8.5 % during a period of high COVID-19 prevalence. GGO showed good inter-rater reliability (Fleiss κ = 0.77); and high COVID-19 specificity (93.7 %, 91.8-95.2) and negative predictive value (NPV; 97.8 %, 96.5-98.6). In subgroup analysis of vaccinated patients, GGO remained a good diagnostic biomarker (specificity 93.1 %, 89.8-95.5; NPV 99.7 %, 98.3-100.0). Patients with COVID-19 were more likely to have higher stroke score (NIHSS (mean +/- SD) 6.9 +/- 6.9, COVID-19 negative, 9.7 +/- 9.0, COVID-19 positive; p = 0.01), carotid occlusions (6.2 % negative, 14.9 % positive; p = 0.02), and larger infarcts on presentation CT (ASPECTS 9.4 +/- 1.5, COVID-19 negative, 8.6 +/- 2.4, COVID-19 positive; p = 0.00). After multivariable logistic regression, GGO (odds ratio 15.7, 6.2-40.1), myalgia (8.9, 2.1-38.2) and higher core body temperature (1.9, 1.1-3.2) were independent COVID-19 predictors. GGO was associated with worse functional outcome on discharge and worse survival after univariate analysis. However, after adjustment for factors including stroke severity, GGO was not independently predictive of functional outcome or mortality.

CONCLUSION

Apical GGO on CTA performed for patients with suspected acute stroke is a reliable diagnostic biomarker for COVID-19, which in combination with clinical features may be useful in COVID-19 triage.

A Day Seven Reflection Circle to Enhance Resilience in Residents after a Difficult Patient Loss

This article was migrated. The article was marked as recommended. Caring for the dying patient can have significant impact on physicians in training, and if unaddressed, can lead to burnout and potentially compromised patient care. The literature suggests didactics and real time supportive interventions such as "post code debriefs" may be most effective in addressing the impact of death on physicians. In this paper, we highlight and discuss a reflection that is conducted several days after the event, when resident physicians are more self-aware of their mental hygiene and the residual impact of challenging event on their personal and professional well-being.

Diagnostic and Prognostic Role of the Modified Diamond-Forrester Model in Combination With Coronary Calcium Score in Acute Chest Pain Patients

BACKGROUND

The aim of this study was to evaluate whether pretest probability (PTP) assessment using the Diamond-Forrester Model (DFM) combined with coronary calcium scoring (CCS) can safely rule out obstructive coronary artery disease (CAD) and 30-day major adverse cardiovascular events (MACE) in acute chest pain patients.

METHODS

We retrospectively evaluated consecutive patients, age ≥18 years, with no known CAD, negative initial electrocardiogram, and troponin level. All patients had coronary computed tomographic angiography (CCTA) with CCS, and our final cohort consisted of 1988 patients. Obstructive CAD was defined as luminal narrowing of ≥50% in 1 or more vessels by CCTA. Patients were classified according to PTP as low (<10%), intermediate (10%-90%), or high (>90%).

RESULTS

The DFM classified 293 (14.7%), 1445 (72.7%), and 250 (12.6%) of patients as low, intermediate, and high risk, respectively, with corresponding 30-day MACE rates of 0.0%, 2.35%, and 14.8%. For patients with intermediate PTP and CCS ≤10, the negative predictive value was 99.2% (95% confidence interval: 98.7-99.8) for 30-day MACE while it was 92.62% (95% confidence interval: 87.9-97.3) for patients with high PTP. Among patients with a high PTP and CCS of zero, the prevalence of 30-day MACE and obstructive CAD remained high (7.07% and 10.1%, respectively).

CONCLUSIONS

In acute chest pain patients without evidence of ischemia on initial electrocardiogram and cardiac troponin, low PTP by DFM or the combination of intermediate PTP and CCS ≤10 had excellent negative predictive values to rule out 30-day MACE. CCS is not sufficient to exclude obstructive CAD and 30-day MACE in patients with high PTP.

A Rare Case of Plantar Epithelioma Cuniculatum Arising from a Wart

A 68-year-old man, a known case of hypertension, coronary artery disease and old cardiovascular accident with right-sided hemiplegia, came with the chief complaints of a large cauliflower like growth with pus discharge on the left heel since 15 years. The patient had sustained a penetrating injury by a thorn on the left heel region few days before the lesion appeared. Dermatological examination revealed a single verrucous lesion measuring 7 × 7 cm on the left heel region associated with discharge of foul smelling cheesy material. There was also a enlarged right inguinal lymph node which was non-tender, firm, measuring 2 cm in diameter with normal overlying skin. X-ray left ankle was done which showed some soft tissue swelling. A skin biopsy showed hyperkeratosis, acanthosis and parakeratosis. Elongated rete ridges with keratinocyte hyperplasia, forming a large mass pressing on the underlying dermis were seen. There was formation of multiple large keratin filled invaginations and crypts. No atypical cells were seen. Based on history, clinical examination and investigations, a diagnosis of epithelium cuniculatum type of verrucous squamous cell carcinoma was made. A wide excision with a flap cover was performed in consultation with the oncosurgeon and the excision sample was sent for histopathological re-examination, which confirmed the diagnosis of epithelioma cuniculatum.

Hematuria following stereotactic body radiation therapy (SBRT) for clinically localized prostate cancer

BACKGROUND

Hematuria following prostate radiotherapy is a known toxicity that may adversely affect a patient's quality of life. Given the higher dose of radiation per fraction using stereotactic body radiation therapy (SBRT) there is concern that post-SBRT hematuria would be more common than with alternative radiation therapy approaches. Herein, we describe the incidence and severity of hematuria following stereotactic body radiation therapy (SBRT) for prostate cancer at our institution.

METHODS

Two hundred and eight consecutive patients with prostate cancer treated with SBRT monotherapy with at least three years of follow-up were included in this retrospective analysis. Treatment was delivered using the CyberKnife® (Accuray) to doses of 35-36.25 Gy in 5 fractions. Toxicities were scored using the CTCAE v.4. Hematuria was counted at the highest grade it occurred in the acute and late setting for each patient. Cystoscopy findings were retrospectively reviewed. Univariate and multivariate analyses were performed. Hematuria-associated bother was assessed via the Expanded Prostate Index Composite (EPIC)-26.

RESULTS

The median age was 69 years with a median prostate volume of 39 cc. With a median follow-up of 48 months, 38 patients (18.3%) experienced at least one episode of hematuria. Median time to hematuria was 13.5 months. In the late period, there were three grade 3 events and five grade 2 events. There were no grade 4 or 5 events. The 3-year actuarial incidence of late hematuria ≥ grade 2 was 2.4%. On univariate analysis, prostate volume (p = 0.022) and history of prior procedure(s) for benign prostatic hypertrophy (BPH) (p = 0.002) were significantly associated with hematuria. On multivariate analysis, history of prior procedure(s) for BPH (p < 0.0001) and α1A antagonist use (p = 0.008) were significantly associated with the development of hematuria.

CONCLUSIONS

SBRT for prostate cancer was well tolerated with hematuria rates comparable to other radiation modalities. Patients factors associated with BPH, such as larger prostate volume, alpha antagonist usage, and prior history of procedures for BPH are at increased risk for the development of hematuria.

Proctitis following stereotactic body radiation therapy for prostate cancer

Background

Proctitis after radiation therapy for prostate cancer remains an ongoing clinical challenge and critical quality of life issue. SBRT could minimize rectal toxicity by reducing the volume of rectum receiving high radiation doses and offers the potential radiobiologic benefits of hypofractionation. This study sought to evaluate the incidence and severity of proctitis following SBRT for prostate cancer.

Methods

Between February 2008 and July 2011, 269 men with clinically localized prostate cancer were treated definitively with SBRT monotherapy at Georgetown University Hospital. All patients were treated to 35-36.25Gy in 5 fractions delivered with the CyberKnife Radiosurgical System (Accuray). Rectal bleeding was recorded and scored using the CTCAE v.4. Telangiectasias were graded using the Vienna Rectoscopy Score (VRS). Proctitis was assessed via the Bowel domain of the Expanded Prostate Index Composite (EPIC)-26 at baseline and at 1, 3, 6, 9, 12, 18 and 24 months post-SBRT.

Results

The median age was 69 years with a median prostate volume of 39 cc. The median follow-up was 3.9 years with a minimum follow-up of two years. The 2-year actuarial incidence of late rectal bleeding ≥ grade 2 was 1.5%. Endoscopy revealed VRS Grade 2 rectal telangiectasias in 11% of patients. All proctitis symptoms increased at one month post-SBRT but returned to near-baseline with longer follow-up. The most bothersome symptoms were bowel urgency and frequency. At one month post-SBRT, 11.2% and 8.5% of patients reported a moderate to big problem with bowel urgency and frequency, respectively. The EPIC bowel summary scores declined transiently at 1 month and experienced a second, more protracted decline between 6 months and 18 months before returning to near-baseline at two years post-SBRT. Prior to treatment, 4.1% of men felt their bowel function was a moderate to big problem which increased to 11.5% one month post-SBRT but returned to near-baseline at two years post-SBRT.

Conclusions

In this single institution cohort, the rate and severity of proctitis observed following SBRT is low. QOL decreased on follow-up; however, our results compare favorably to those reported for patients treated with alternative radiation modalities. Future prospective randomized studies are needed to confirm these observations.

Obstructive voiding symptoms following stereotactic body radiation therapy for prostate cancer

Background

Obstructive voiding symptoms (OVS) are common following prostate cancer treatment with radiation therapy. The risk of urinary retention (UR) following hypofractionated radiotherapy has yet to be fully elucidated. This study sought to evaluate OVS and UR requiring catheterization following SBRT for prostate cancer.

Methods

Patients treated with SBRT for localized prostate cancer from February 2008 to July 2011 at Georgetown University were included in this study. Treatment was delivered using the CyberKnife® with doses of 35 Gy-36.25 Gy in 5 fractions. UR was prospectively scored using the CTCAE v.3. Patient-reported OVS were assessed using the IPSS-obstructive subdomain at baseline and at 1, 3, 6, 9, 12, 18 and 24 months. Associated bother was evaluated via the EPIC-26.

Results

269 patients at a median age of 69 years received SBRT with a median follow-up of 3 years. The mean prostate volume was 39 cc. Prior to treatment, 50.6% of patients reported moderate to severe lower urinary track symptoms per the IPSS and 6.7% felt that weak urine stream and/or incomplete emptying were a moderate to big problem. The 2-year actuarial incidence rates of acute and late UR ≥ grade 2 were 39.5% and 41.4%. Alpha-antagonist utilization rose at one month (58%) and 18 months (48%) post-treatment. However, Grade 3 UR was low with only 4 men (1.5%) requiring catheterization and/or TURP. A mean baseline IPSS-obstructive score of 3.6 significantly increased to 5.0 at 1 month (p < 0.0001); however, it returned to baseline in 92.6% within a median time of 3 months. Late increases in OVS were common, but transient. Only 7.1% of patients felt that weak urine stream and/or incomplete emptying was a moderate to big problem at two years post-SBRT (p = 0.6854).

Conclusions

SBRT treatment caused an acute increase in OVS which peaked within the first month post-treatment, though acute UR requiring catheterization was rare. OVS returned to baseline in > 90% of patients within a median time of three months. Transient Late increases in OVS were common. However, less than 10% of patients felt that OVS were a moderate to big problem at two years post-SBRT.

Patient-reported urinary incontinence following stereotactic body radiation therapy (SBRT) for clinically localized prostate cancer

Purpose

Urinary incontinence (UI) following prostate radiotherapy is a rare toxicity that adversely affects a patient’s quality of life. This study sought to evaluate the incidence of UI following stereotactic body radiation therapy (SBRT) for prostate cancer.

Methods

Between February, 2008 and October, 2010, 204 men with clinically localized prostate cancer were treated definitively with SBRT at Georgetown University Hospital. Patients were treated to 35–36.25 Gray (Gy) in 5 fractions delivered with the CyberKnife (Accuray). UI was assessed via the Expanded Prostate Index Composite (EPIC)-26.

Results

Baseline UI was common with 4.4%, 1.0% and 3.4% of patients reporting leaking > 1 time per day, frequent dribbling and pad usage, respectively. Three year post treatment, 5.7%, 6.4% and 10.8% of patients reported UI based on leaking > 1 time per day, frequent dribbling and pad usage, respectively. Average EPIC UI summary scores showed an acute transient decline at one month post-SBRT then a second a gradual decline over the next three years. The proportion of men feeling that their UI was a moderate to big problem increased from 1% at baseline to 6.4% at three years post-SBRT.

Conclusions

Prostate SBRT was well tolerated with UI rates comparable to conventionally fractionated radiotherapy and brachytherapy. More than 90% of men who were pad-free prior to treatment remained pad-free three years following treatment. Less than 10% of men felt post-treatment UI was a moderate to big problem at any time point following treatment. Longer term follow-up is needed to confirm late effects.

Clinical characteristics and management of late urinary symptom flare following stereotactic body radiation therapy for prostate cancer

Purpose: Stereotactic body radiation therapy (SBRT) is increasingly utilized as primary treatment for clinically localized prostate cancer. While acute post-SBRT urinary symptoms are well recognized, the late genitourinary toxicity of SBRT has not been fully described. Here, we characterize the clinical features of late urinary symptom flare and recommend conservative symptom management approaches that may alleviate the associated bother.

Methods: Between February 2008 and August 2011, 216 men with clinically localized prostate cancer were treated definitively with SBRT at Georgetown University Hospital. Treatment was delivered using the CyberKnife with doses of 35–36.25 Gy in five fractions. The prevalence of each of five Common Terminology Criteria for Adverse Events (CTCAE) graded urinary toxicities was assessed at each follow-up visit. Medication usage was documented at each visit. Patient-reported urinary symptoms were assessed using the American Urological Association (AUA) symptom score and the Expanded Prostate Cancer Index Composite (EPIC)-26 at 1, 3, 6, 9, 12, 18, and 24 months. Late urinary symptom flare was defined as an increase in the AUA symptom score of ≥5 points above baseline with a degree of severity in the moderate to severe range (AUA symptom score ≥15). The relationship between the occurrence of flare and pre-treatment characteristics were examined.

Results: For all patients, the AUA symptom score spiked transiently at 1 month post-SBRT. Of the 216 patients, 29 (13.4%) experienced a second transient increase in the AUA symptom score that met the criteria for late urinary symptom flare. Among flare patients, the median age was 66 years compared to 70 for those without flare (p = 0.007). In patients who experienced flare, CTCAE urinary toxicities including dysuria, frequency/urgency, and retention peaked at 9–18 months, and alpha-antagonist utilization increased at 1 month post-treatment, rose sharply at 12 months post-treatment, and peaked at 18 months (85%) before decreasing at 24 months. The EPIC urinary summary score of flare patients declined transiently at 1 month and experienced a second, more protracted decline between 6 and 18 months before returning to near baseline at 2-year post-SBRT. Statistically and clinically significant increases in patient-reported frequency, weak stream, and dysuria were seen at 12 months post-SBRT. Among flare patients, 42.9% felt that urination was a moderate to big problem at 12 months following SBRT.

Conclusion: In this study, we characterize late urinary symptom flare following SBRT. Late urinary symptom flare is a constellation of symptoms including urinary frequency/urgency, weak stream, and dysuria that transiently occurs 6–18 months post-SBRT. Provision of appropriate anticipatory counseling and the maintenance of prophylactic alpha-antagonists may limit the bother associated with this syndrome.

Incidence of patient-reported urinary incontinence after stereotactic body radiation therapy for clinically localized prostate cancer

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Background: Urinary incontinence (UI) following prostate radiotherapy is a rare toxicity that adversely affects a patient’s quality of life. The potential for hypofractionated radiotherapy to increase the risk of UI was investigated. This study sought to evaluate the incidence and severity of UI following stereotactic body radiation therapy (SBRT) for prostate cancer. Methods: Between February 2008 and August 2011, 216 men with clinically localized prostate cancer were treated definitively with SBRT at Georgetown University Hospital. Patients were treated to 35 to 36.25Gy in five fractions delivered with the CyberKnife (Accuray). UI was defined as self-reported involuntary urine loss and was assessed via the UI domain of the Expanded Prostate Index Composite (EPIC)-26 at baseline and at months 1, 3, 6, 9, 12, 18, and 24. EPIC scores range from 0 to 100 with lower values representing worsening incontinence. The minimally important difference (MID) was defined as a change of one-half standard deviation from the baseline. Results: The median age was 66 with a median prostate volume of 38 cc. The median follow-up was 3.2 years. Baseline UI was common with 22.0%, 26.2%, and 3.3% of patients reporting leaking, dribbling and pad usage, respectively. At two year post treatment, 31.1%, 34.7%, and 7.1% of patients reported some degree of incontinence based on leaking, dribbling and pad usage, respectively. Average EPIC UI domain scores showed a slow decline over the first two years following treatment. At two year post treatment, the median decreased from a baseline of 92.1 to 88.0. This change was statistically (p < 0.001) but not clinically significant (MID=6.7). The proportion of men feeling that their UI was a moderate to big problem increased from 1% at baseline to 6% at two years post treatment. Conclusions: SBRT for clinically localized prostate cancer was well tolerated with UI rates comparable to conventionally fractionated radiotherapy and brachytherapy. Greater than 90% of men who were pad-free prior to treatment remained pad-free two years following treatment. Less than 10% of men felt posttreatment UI was a moderate to big problem.

Urinary obstruction following stereotactic body radiation therapy (SBRT) for clinically localized prostate cancer

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Background: Obstructive urinary symptoms are common following prostate cancer treatment with radiation therapy. Given the higher dose of radiation per fraction using stereotactic body radiation therapy (SBRT) there is concern that post-SBRT obstructive urinary symptoms would be more severe. This study sought to evaluate obstructive urinary symptoms and urinary retention requiring catheterization following SBRT for prostate cancer. Methods: Patients treated with SBRT monotherapy for localized prostate cancer from August 2007 to July 2011 at Georgetown University Hospital with a minimum of two years of follow-up were included in this study. Treatment was delivered using the CyberKnife with doses of 35 Gy to 36.25 Gy in five fractions. Urinary retention was recorded and scored using the CTCAE v.4. Patient-reported urinary symptoms were assessed using the International Prostate Symptom Score (IPSS) before treatment and at months 1, 3, 6, 9, and 12 and every six months thereafter. Results: Two hundred sixty nine patients at a median age of 69 received SBRT with a median follow-up of three years. Prior to treatment, 32.1% of patients utilized alpha-antagonists and 17.8% were dissatisfied with their urinary function. The two-year actuarial incidence rates of acute and late urinary retention greater than or equal to grade 2 were 39.5% and 41.4%. Alpha-antagonist utilization rose at one month (57.9%) and 18 months (48.0%) post-treatment. However, grade 3 urinary retention was low with four men (1.5%) requiring catheterization and/or transurethral resection of the prostate. A mean baseline IPSS obstructive symptom score of 3.6 significantly increased to 5.0 at one month (p < 0.0001), however returned to baseline at three months (p = 0.74). Late IPSS increases were common, but transient. The IPSS obstructive symptom score returned to baseline in 79.6% of patients by six months and 92.6% by two years. Dissatisfaction with urinary function declined to 14% by two years post treatment (p < 0.05). Conclusions: Treatment of prostate cancer with SBRT resulted in an acute increase in obstructive urinary symptoms, which peaked at one month post-treatment. However, the risk of acute urinary retention requiring catheterization was low. Obstructive urinary symptoms returned to baseline in the majority of patients by six months and in more than 90% by two years.

Potency preservation following stereotactic body radiation therapy for prostate cancer

BACKGROUND

Erectile dysfunction after prostate radiation therapy remains an ongoing challenge and critical quality of life issue. Given the higher dose of radiation per fraction using stereotactic body radiation therapy (SBRT) there is concern that post-SBRT impotency would be higher than conventional radiation therapy approaches. This study sought to evaluate potency preservation and sexual function following SBRT for prostate cancer.

METHODS

Between February 2008 and March 2011, 216 men with clinically localized prostate cancer were treated definitively with SBRT monotherapy at Georgetown University Hospital. Potency was defined as the ability to have an erection firm enough for intercourse with or without sexual aids while sexual activity was defined as the ability to have an erection firm enough for masturbation and foreplay. Patients who received androgen deprivation therapy (ADT) were excluded from this study. Ninety-seven hormone-naïve men were identified as being potent at the initiation of therapy and were included in this review. All patients were treated to 35-36.25 Gy in 5 fractions delivered with the CyberKnife Radiosurgical System (Accuray). Prostate specific antigen (PSA) and total testosterone levels were obtained pre-treatment, every 3 months for the first year and every 6 months for the subsequent year. Sexual function was assessed with the Sexual Health Inventory for Men (SHIM), the Expanded Prostate Index Composite (EPIC)-26 and Utilization of Sexual Medication/Device questionnaires at baseline and all follow-up visits.

RESULTS

Ninety-seven men (43 low-, 50 intermediate- and 4 high-risk) at a median age of 68 years (range, 48-82 years) received SBRT. The median pre-treatment PSA was 5.9 ng/ml and the minimum follow-up was 24 months. The median pre-treatment total serum testosterone level was 11.4 nmol/L (range, 4.4-27.9 nmol/L). The median baseline SHIM was 22 and 36% of patients utilized sexual aids prior to treatment. Although potency rates declined following treatment: 100% (baseline); 68% (6 months); 62% (12 months); 57% (18 months) and 54.4% (24 months), 78% of previously potent patients had erections sufficient for sexual activity at 24 months post-treatment. Overall sexual aid utilization increased from 36% at baseline to 49% at 24 months. Average EPIC sexual scores showed a slow decline over the first two years following treatment: 77.6 (baseline); 68.7 (6 months); 63.2 (12 months); 61.9 (18 months); 59.3 (24 months). All sexual functions including orgasm declined with time. Prior to treatment, 13.4% of men felt their sexual function was a moderate to big problem which increased to 26.7% two years post treatment. Post-treatment testosterone levels gradually decreased with a median value at two year follow-up of 10.7 nmol/L. However, the average EPIC hormonal scores did not illustrate a statistically significant difference two years post-treatment. Review of the radiation doses to the penile bulb in this study, a potential marker of post-treatment sexual function, revealed that the dose was relatively low and at these low doses the percentage of the penile bulb receiving 29.5 Gy did not correlate with the development of ED.

CONCLUSIONS

Men undergoing SBRT monotherapy for prostate cancer report sexual outcomes comparable to those reported for conventional radiation modalities within the first 24 months after treatment. Longer follow-up is required to confirm the durability of these findings.

Influence of evolutionary events on the Indian subcontinent on the phylogeography of dengue type 3 and 4 viruses

During 1960-80 dengue disease profile in India was mild despite circulation of all four serotypes of dengue virus (DENV). Increase in disease severity with a concomitant change in the population of DENV-1 and 2 have been reported since then. To determine population dynamics of DENV-3 and 4, the envelope (E) gene sequence was determined for 16 Indian isolates of DENV-3 and 11 of DENV-4 and analyzed together with 97 DENV-3 and 43 DENV-4 global sequences. All Indian DENV-3 isolates belonged to genotype III, lineages C, D, E and F. Lineage F was newly identified and represented non-circulating viruses. Three non-conservative amino acid changes in domain I, II & III were identified during the transition from lineages F/E, associated with mild disease, to A-D, associated with severe disease. For DENV-4, the current viruses clustered in genotype I, lineage C, whilst the isolates from 1960s formed the new genotype V. A 1979 Indian isolate of DENV-4 was found to be an inter-genotypic recombinant of Sri Lankan isolate (1978) of genotype I and Indian isolate (1961) of genotype V. The rates of nucleotide substitution and time to the most recent common ancestor (tMRCA) estimated for DENV-3 (1782-1934) and DENV-4 (1719-1931) were similar to earlier reports. However, the divergence time for genotype III of DENV-3, 1938-1963, was a more accurate estimate with the inclusion of Indian isolates from the 1960s. By phylogeographical analysis it was revealed that DENV-3 GIII viruses emerged from India and evolved through Sri Lanka whilst DENV-4 emerged and dispersed from India. The present study demonstrates the crucial role that India/Sri Lanka have played in the evolution and dispersion of the major genotypes, GIII of DENV-3 and GI of DENV-4 which are more virulent and show higher dissemination potential.

Thermal properties of rhodopsin: insight into the molecular mechanism of dim-light vision

Rhodopsin has developed mechanisms to optimize its sensitivity to light by suppressing dark noise and enhancing quantum yield. We propose that an intramolecular hydrogen-bonding network formed by ∼20 water molecules, the hydrophilic residues, and peptide backbones in the transmembrane region is essential to restrain thermal isomerization, the source of dark noise. We studied the thermal stability of rhodopsin at 55 °C with single point mutations (E181Q and S186A) that perturb the hydrogen-bonding network at the active site. We found that the rate of thermal isomerization increased by 1-2 orders of magnitude in the mutants. Our results illustrate the importance of the intact hydrogen-bonding network for dim-light detection, revealing the functional roles of water molecules in rhodopsin. We also show that thermal isomerization of 11-cis-retinal in solution can be catalyzed by wild-type opsin and that this catalytic property is not affected by the mutations. We characterize the catalytic effect and propose that it is due to steric interactions in the retinal-binding site and increases quantum yield by predetermining the trajectory of photoisomerization. Thus, our studies reveal a balancing act between dark noise and quantum yield, which have opposite effects on the thermal isomerization rate. The acquisition of the hydrogen-bonding network and the tuning of the steric interactions at the retinal-binding site are two important factors in the development of dim-light vision.

Thermal decay of rhodopsin: role of hydrogen bonds in thermal isomerization of 11-cis retinal in the binding site and hydrolysis of protonated Schiff base

Although thermal stability of the G protein-coupled receptor rhodopsin is directly related to its extremely low dark noise level and has recently generated considerable interest, the chemistry behind the thermal decay process of rhodopsin has remained unclear. Using UV-vis spectroscopy and HPLC analysis, we have demonstrated that the thermal decay of rhodopsin involves both hydrolysis of the protonated Schiff base and thermal isomerization of 11-cis to all-trans retinal. Examining the unfolding of rhodopsin by circular dichroism spectroscopy and measuring the rate of thermal isomerization of 11-cis retinal in solution, we conclude that the observed thermal isomerization of 11-cis to all-trans retinal happens when 11-cis retinal is in the binding pocket of rhodopsin. Furthermore, we demonstrate that solvent deuterium isotope effects are involved in the thermal decay process by decreasing the rates of thermal isomerization and hydrolysis, suggesting that the rate-determining step of these processes involves breaking hydrogen bonds. These results provide insight into understanding the critical role of an extensive hydrogen-bonding network on stabilizing the inactive state of rhodopsin and contribute to our current understanding of the low dark noise level of rhodopsin, which enables this specialized protein to function as an extremely sensitive biological light detector. Because similar hydrogen-bonding networks have also been suggested by structural analysis of two other GPCRs, beta1 and beta2 adrenergic receptors, our results could reveal a general role of hydrogen bonds in facilitating GPCR function.

Synthesis and bronchodilator activity of new quinazolin derivative

Taking lead from a naturally occurring quinazolin vasicine, a number of compounds were developed and evaluated for bronchodilator and anti-allergic activities. One of these compounds was 2,4-diethoxy-6,7,8,9,10,12-hexahydroazepino[2,1-b]quinazolin-12-one, hereinafter named 95-4, exhibited marked bronchodilator activity evaluated on contracted trachea or constricted tracheo-bronchial tree. On intestinal smooth muscle too it showed relaxant effect. Tracheal relaxant effect was not found to be mediated through beta-adrenoceptors. Cumulative dose-response study with acetylcholine and histamine indicated for its non-specific direct effect on smooth muscles. 95-4 was found to be more potent than theophylline and less to that of salbutamol on dose basis. Tested by a number of experimental models, it was found devoid of anti-allergic activity. It was also found to be free from any adverse effect. 95-4 due to its marked bronchial muscle relaxant effect can find use in conditions associated with spasm of bronchial muscles.

Bilateral ptosis following wasp sting

We report a case of bilateral ptosis due to wasp sting which was completely treatable.

Cannabis psychosis and acute schizophrenia. a case-control study from India

Twenty cases of cannabis psychosis were compared with a control group of 20 patients with 'acute schizophrenic episode' on a number of demographic, clinical, illness-related and outcome variables in a case-control study design using a retrospective chart review. The two groups were comparable on demographic, past and family histories of mental illness, premorbid personality, psychomotor activity, Schneiderian first-rank symptoms and mild cognitive deficits. The cases, in contrast to the control group, had a psychosis of shorter duration characterized by reactive and congruent affect, relative absence of schizophrenic formal thought disorder and a predominantly polymorphic clinical picture. Relapse was always preceded by cannabis use. This study suggests that, in spite of certain overlaps, 'cannabis psychosis' may still be considered nosologically distinct from schizophrenia in India. The implication of the study is that the role of cannabis in any acute psychosis should be investigated carefully so as to prevent an overdiagnosis of schizophrenia.

A community day care programme for psychiatric patients: the role of occupational therapy

This paper examines the need for and role of occupational therapy in the organization and functioning of a community day care centre for psychiatric patients in a developing country. It highlights the debilitating effects of institutionalization associated with a previously established system of institutional care and explores the role of occupational therapy in facilitating the move away from that approach towards community-based day care centres for such patients. The paper describes the community care programme; the patients attending the programme; the methods used by occupational therapists to evaluate patients; and the effectiveness of the various individual, group and family focused methods of treatment deployed.

Autoradiographic localization of 3H-digoxin binding by neural cells in the medulla

The purpose of this investigation was to localize binding sites for the cardiac glycoside digoxin in the medulla of the rat in vivo. Adult male Sprague-Dawley rats were injected (IV) with 3H-digoxin and killed 30 minutes later. Autoradiographs of medullas showed evidence of 3H-digoxin binding to small- and medium-sized neural cells in the regions of the nucleus solitarius, dorsal motor nucleus of the vagus, area postrema, and in the zone between the area postrema and the underlying neuropil. However, the parasympathetic preganglionic neurons of the dorsal motor nucleus were not labeled. The 3H-digoxin-labeled cells in the medulla were located mainly in the commissural and medial portions of nucleus solitarius at the level of the area postrema. Animals injected with unlabeled digoxin followed by 3H-digoxin showed reduced binding of radioactivity. The small- and medium-sized neurons of the caudal portions of the nucleus solitarius are internuncial in position with respect to cardiovascular afferents of the glossopharyngeal and vagus nerves and sympathetic and parasympathetic cardiovascular efferent neurons of the medulla. The results of this study suggest that these 3H-digoxin-labeled cells, presumably neurons of nucleus solitarius, may possess high affinity binding sites for digoxin. Further, the area postrema, which lacks a blood-brain barrier, may provide a portal of entry for 3H-digoxin into regions of the medulla known to contain neurons that play a role in the regulation of cardiac rhythm.