Fine mapping of a new common bean anthracnose resistance gene (Co-18) to the proximal end of Pv10 in Indian landrace KRC-5

KEY MESSAGE

Mapping and fine mapping of bean anthracnose resistance genes is a continuous process. We report fine mapping of anthracnose resistance gene Co-18 which is the first anthracnose gene mapped to Pv10. The discovery of resistance gene is a major gain in the bean anthracnose pathosystem research. Among the Indian common bean landraces, KRC-5 exhibit high levels of resistance to the bean anthracnose pathogen Colletotrichum lindemuthianum. To precisely map the anthracnose resistance gene, we used a Recombinant Inbred Line (F2:9 RIL) population (KRC-5 × Jawala). The inheritance test revealed that KRC-5 carries a dominant resistance gene temporarily designated as Co-18. We discovered two RAPD markers linked to Co-18 among 287 RAPD markers. These RAPD markers were eventually developed into SCARs (Sc-OPR15 and Sc-OPF6) and flank Co-18 on chromosome Pv10 at a distance of 5.3 and 4.2 cM, respectively. At 4.0-4.1 Mb on Pv10, we detected a SNP (single-nucleotide polymorphism) signal. We synthesized 58 SSRs and 83 InDels from a pool of 135 SSRs and 1134 InDels, respectively. Five SSRs, four InDels, and two SCARs were used to generate the high-density linkage map, which led to the identification of two SSRs (SSR24 and SSR36) that are tightly linked to Co-18. These two SSRs flank the Co-18 to 178 kb genomic region with 13 candidate genes including five NLR (nucleotide-binding and leucine-rich repeat) genes. The closely linked markers SSR24 and SSR36 will be used in cloning and pyramiding of the Co-18 gene with other R genes to develop durable resistant bean varieties.

Monitoring and method validation of organophosphorus/organochlorine pesticide residues in vegetables and fruits by gas chromatography

In this study, an analytical method was developed and validated for the assessment of pesticide residues in commonly consumed vegetables and fruits. Fresh samples of apple, green peas, tomatoes, and cucumbers were processed and subjected to analysis using a modified QuEChERS (quick, easy, cheap, effective, rugged, safe) extraction technique. Subsequently, quantification of pesticide residues was conducted utilizing gas chromatography (GC)-electron capture detector. Extraction and cleanup parameters were meticulously optimized, resulting in a modification of the original QuEChERS method. This modification aimed to reduce solvent consumption, making the study more environmentally friendly. The developed method was validated in terms of selectivity, specificity, linearity, precision, and accuracy by following the SANTE guidelines. Calibration curves showed good linearity (r > 0.99) within the test range. Precision was evaluated by intra- and inter-day experiments with an acceptable relative standard deviation (<20.0%). Recovery was assessed at the limit of quantification level and was observed to fall within the range of 70%-120%, with relative standard deviations below 5.45%. The validated method presented here can be applied to analyze pesticide residues in various other vegetables, fruits, and cereals. It is essential for ongoing monitoring of pesticide residues to ensure public safety.

Dissipation kinetics, residue determination and consumer risk assessment of acephate on green pea by gas chromatography-electron capture detector

The present study on "acephate persistence on green pea" was conducted in SKUAST-Kashmir. The study aimed to determine the persistence, dissipation kinetics and waiting period of acephate on green pea. Acephate was sprayed at 75% soluble powder (SP) at 560 g a.i.ha-1 at the fruiting stage followed by another application at a 10 day interval. A rapid and accurate method (quick, easy, cheap, effective, rugged and safe, QuEChERS) was used for extraction and the residue was determined by gas chromatography-electron capture detection on a CPSIL-8CB capillary column (0.25um film thickness, 0.25 mm i.d, 30 m length). At the fortification levels of 0.05, 0.1 and 0.5 mg kg-1 , the percentage recovery of acephate on green pea was found in the range of 71-107%. The initial deposit of green pea was estimated to be 0.37 mg kg-1 . At the indicated dose, the residue of acephate on green pea dissipated below the limit of quantification of 0.05 mg kg-1 after 10 days. Acephate degradation was quick in green pea, with a half-life of 4.07 days. For safe eating of green peas, a 10 day waiting period is recommended. The gas chromatography-electron capture detection technique was validated by following the SANTE standards.

Morpho-cultural, pathological and molecular variability in Phloeospora maculans causing leaf spot of mulberry (Morus species) in India

BACKGROUND

Leaf spot disease (LSD) of mulberry caused by Phloeospora maculans is a major threat to the silk industry of Jammu and Kashmir, India, therefore, it was necessary to study the population structure of the pathogen for successful management of the disease.

METHODS AND RESULTS

To understand the diversity in the Phloeospora maculans, a combination of conventional (morphological, cultural and pathological) and molecular (ISSR markers) approaches were employed to discern the variability in 27 isolates collected from Srinagar, Bandipora, and Baramulla districts of Jammu and Kashmir, India. The studies revealed a high level of variability in the pathogen. Based on the morpho-cultural and pathological studies, the pathogen isolates were grouped into different categories based on colony growth, texture, margin and colour besides changes in colour of medium, incubation period, leaf area infected, etc.A high level of polymorphism was observed in different isolates of P. maculans using ISSR markers, which indicated that these markers are suitable for studying the genetic diversity in this pathogen. All the isolates (27) of P. maculans were clustered into two groups or populations as indicated by mean delta K value. Analysis of molecular variance revealed the low genetic variation among the populations (1.08%) and a high level of genetic variation within the populations (98.91%). Fst value was found to be 0.01 indicating smaller amount of genetic differentiation between the populations against calculated P-value of 0.29.

CONCLUSION

A high level of diversity based on morphological, cultural, pathological and molecular levels was observed in Phloeospora maculans collected from various districts of Kashmir valley, which indicates that the study of population structure is necessary for successful management of the disease.

Morphological, pathogenic and genetic diversity in Diplodia seriata associated with black rot canker of apple in India

Apple cankers are extremely destructive diseases threatening the global apple industry through direct and indirect losses. The population structure of the pathogens is of paramount significance for the development of efficient management strategies. Therefore, phenotypic, pathogenic, and genetic diversity of Diplodia seriata causing black rot canker of apple was investigated in this study. All the isolates were included for investigating the in vitro mycelial growth, conidial dimensions, and pathogenic variability on two-year-old potted apple seedlings. The ISSR approach was used to investigate the molecular diversity of D. seriata. Mycelial growth rates were found to vary significantly amongst the isolates; however, there were no major variations seen between the different geographical groupings of isolates. Pathogenicity tests revealed variations in the size of cankers among the isolates indicating the presence of virulence variability. The isolates were segregated into three virulence groups based on canker length. The Bayesian analyses of ISSR data divided the isolates into two genetic clusters. The genetic clustering of the isolates revealed no relationship with geographical origin of the isolates. Furthermore, no direct relationship of genetic clustering was observed with morphological or pathogenic variability. The ISSR primers revealed very high level of variability in D. seriata; however, no distinct populations of the pathogen existed which is an indication of high level of gene flow between the diverse geographical populations. According to our knowledge, this is the first thorough investigation on the diversity of D. seriata associated with apple black rot canker in India.

Development of PCR based SSR markers for Wilsonomyces carpophilus and a PCR based diagnosis protocol for the early detection of shot hole disease in stone fruit crops

BACKGROUND

The conidial Ascomycota fungus Wilsonomyces carpophilus causing shot hole in stone fruits is a major constraint in the production of stone fruits worldwide. Shothole disease symptoms appear on leaves, fruits, and twigs. Successful isolation of the pathogen from different hosts on synthetic culture medium is a time consuming and tedious procedure for identification of the pathogen based on morpho-cultural characterization.

METHODS AND RESULTS

The present research was carried out to develop a successful PCR based early detection protocol for the shot hole disease of stone fruits, viz., peach, plum, apricot, cherry, and almond using the pathogen specific SSR markers developed from the Wilsonomyces carpophilus genome using Genome-wide Microsatellite Analysing Tool package (GMATA) software. Diseased leaf samples of different stone fruits were collected from the SKUAST-K orchard and the pathogen was isolated on potato dextrose agar (PDA) medium and maintained on Asthana and Hawkers' medium with a total of 50 pathogen isolates comprised of 10 isolates each from peach, plum, apricot, cherry and almond. The DNA was extracted from both healthy and infected leaf samples of different stone fruits. The DNA was also extracted from the isolated pathogen cultures (50 isolates). Out of 2851 SSR markers developed, 30 SSRs were used for the successful amplification of DNA extracted from all the 50 pathogen isolates. These SSRs were used for the amplification DNA from shot hole infected leaf samples of different stone fruits, but the amplification was not observed in the control samples (DNA from healthy leaves), thus confirming the detection of this disease directly from the shot hole infected samples using PCR based SSR markers. To our knowledge, this forms the first report of SSR development for the Wilsonomyces carpophilus and their validation for the detection of shot hole disease directly from infected leaves.

CONCLUSION

PCR based SSR makers were successfully developed and used for the detection of Wilsonomyces carpophilus causing shot hole disease in stone fruits including almond in nuts for the first time. These SSR markers could successfully detect the pathogen directly from the infected leaves of stone fruits namely peach, plum, apricot and cherry including almond from the nuts.

Genetic footprint of population diversity and genetic structure of Venturia inaequalis infecting apple (Malus × domestica Borkh.)

Apple scab instigated by Venturia inaequalis impels remarkable losses to apple fruit production. In an effort to comprehend the key mechanisms of evolutionary potential defining V. inaequalis population, 132 isolates of V. inaequalis from five commercial apple orchards were collected and assayed using 14 microsatellite markers. The average diversity was observed within the individuals of populations based on the Shannon-Wieners index (I) and observed heterozygosity (Ho) was average but considerably lower than expected heterozygosity (He). The genetic differentiation based on FST values was revealed as an average measure of divergence between populations and had varying proportions of gene flow and migration among themselves. Analysis of Molecular Variance (AMOVA) revealed that variance (94%) was dispersed across individuals with a significant (6%) variation between populations from different regions. To examine host specialization within the V. inaequalis population, the assignment approach based on K-means of clustering (an unsupervised machine learning approach), revealed that the clustering method supported three clusters at (K = 3) and three major clusters were also observed in Principle Component Analysis (PCA). Additionally, Nei's genetic distance values, pairwise estimates of genetic differentiation, dendrogram using the neighbor-joining and PCoA revealed the random distribution of V. Inaequalis isolates that depicted a high proportion of genotypic diversity within populations and population genetic structure.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03672-2.

Whole genome sequencing of Wilsonomyces carpophilus, an incitant of shot hole disease in stone fruits: insights into secreted proteins of a necrotrophic fungal repository

BACKGROUND

Shot hole is one of the important fungal diseases in stone fruits viz., peach, plum, apricot and cherry caused by Wilsonomyces carpophilus and almond among nut crops. Fungicides significantly decrease the disease. Pathogenicity studies proved a wide host range of the pathogen infecting all stone fruits and almond among the nut crops, however, the mechanism underlying host-pathogen interaction is still unknown. Molecular detection of the pathogen using polymerase chain reaction (PCR) based simple sequence repeat (SSR) markers is also unknown due to the unavailability of the pathogen genome.

METHODS AND RESULTS

We examined the morphology, pathology and genomics of the Wilsonomyces carpophilus. Whole genome sequencing of the W. carpophilus was carried out by Illumina HiSeq and PacBio high throughput sequencing plate-forms through hybrid assembly. Constant selection pressure alters the molecular mechanism of the pathogen causing disease. The studies revealed that the necrotrophs are more lethal with a complex pathogenicity mechanism and little-understood effector repositories. The different isolates of necrotrophic fungus W. carpophilus causing shot hole in stone fruits namely peach, plum, apricot and cherry, and almonds among the nut crops showed a significant variation in their morphology, however, the probability value (p = 0.29) suggests in-significant difference in the pathogenicity. Here, we reported draft genome of W. carpophilus of size 29.9 Mb (Accession number: PRJNA791904). A total of 10,901 protein-coding genes were predicted, including heterokaryon incompatibility genes, cytochrome-p450 genes, kinases, sugar transporters among others. We found 2851 simple sequence repeats (SSRs), tRNAs, rRNAs and pseudogenes in the genome. The most prominent proteins showing necrotrophic lifestyle of the pathogen were hydrolases, polysaccharide-degrading enzymes, esterolytic, lipolytic, and proteolytic enzymes accounted for 225 released proteins. Among the 223 fungal species, top-hit species distribution revealed the majority of hits against the Pyrenochaeta species followed by Ascochyta rabiei and Alternaria alternata.

CONCLUSION

Draft genome of W. carpophilus is 29.9 Mb based on Illumina HiSeq and PacBio hybrid assembly. The necrotrophs are more lethal with a complex pathogenicity mechanism. A significant variation in morphology was observed in different pathogen isolates. A total of 10,901 protein-coding genes were predicted in the pathogen genome including heterokaryon incompatibility, cytochrome-p450 genes, kinases and sugar transporters. We found 2851 SSRs, tRNAs, rRNAs and pseudogenes, and prominent proteins showing necrotrophic lifestyle such as hydrolases, polysaccharide-degrading enzymes, esterolytic, lipolytic and proteolytic enzymes. The top-hit species distribution were against the Pyrenochaeta spp. followed by Ascochyta rabiei.

CRISPR/Cas9 based mlo-mediated resistance against Podosphaera xanthii in cucumber (Cucumis sativus L.)

Powdery mildews (PM) are common and severe pathogen groups that threaten plants, and PM resistance is complex and polygenic in cucumbers. Previously mlo-based resistance was reported in various plants, including cucumber, with generated loss-of CsaMLO function mutants. However, mlo-based resistance in cucumber is also complex and involves additional mechanisms such as hypersensitive response (HR) and papillae formation. For this reason, we focused on determining the mlo-based powdery mildew resistance mechanism in cucumber. CRISPR/Cas9 was used in the present study to generate loss-of-function mutants for CsaMLO1, CsaMLO8, and CsaMLO11 of PM susceptible ADR27 cucumber inbred lines and CsaMLO mutants were obtained and validated. Trypan Blue and DAB staining were performed to detect Podosphaera xanthii germination/penetration rates and accumulation of Reactive Oxygen Species (ROS). Our results indicate that PM-susceptibility associated CsaMLOs in cucumber are negative regulators in different defense mechanisms against powdery mildew at early and late stages of infection. Further, the experiment results indicated that CsaMLO8 mutation-based resistance was associated with the pre-invasive response, while CsaMLO1 and CsaMLO11 could be negative regulators in the post-invasive defense response in cucumber against P. xanthii. Although the loss-of CsaMLO8 function confers the highest penetration resistance, CsaMLO1 and CsaMLO11 double mutations could be potential candidates for HR-based resistance against PM pathogen in cucumber. These results highlighted the crucial role of CRISPR/Cas9 to develop PM resistant cucumber cultivars, possessing strong pre-invasive defense with CsaMLO8 or post-invasive with CsaMLO1/CsaMLO11 mutations.

Fusarium chlamydosporum, causing wilt disease of chili (Capsicum annum L.) and brinjal (Solanum melongena L.) in Northern Himalayas: a first report

Chili (Capsicum annuum L.) and brinjal (Solanum melongena L.) are the most widely grown solanaceous crops in the world. However, their production has reduced over several years due to the attack of various fungal and bacterial pathogens and various abiotic factors. Still, the major constrain in their production are pathogens with fungal etiology, especially the fungal wilt of solanaceous crops. Fusarium oxysporum and Fusarium solani have been previously identified as the pathogens causing wilt disease in chili and brinjal. Recently, a new fungal pathogen F. equiseti has been reported as the causal agent of wilt disease infecting chili. The current study focused on identifying fungal pathogens associated with the wilted plants of chili and brinjal, collected from different parts of the Himalayan region of Kashmir valley, through morpho-cultural and molecular characterization. DNA extraction, PCR amplification, and sequencing were performed on various isolates. DNA barcoding using the internal transcribed spacer region (ITS) was used to identify the pathogen followed by the pathogenicity test. Further confirmation of the pathogen was done by sequencing of transcription elongation factor (TEF) and Calmodulin (CAL2). In current study Fusarium chlamydosporum has been reported as the wilt causing pathogen of chili and brinjal for the first time in Kashmir Himalayas.

Phaseolus vulgaris-Colletotrichum lindemuthianum Pathosystem in the Post-Genomic Era: An Update

Phaseolus vulgaris-Colletotrichum lindemuthianum is one among the oldest host and pathogen interface. Researchers have taken painstaking efforts across the world for understanding the dialogue during early and late phases of interaction. Collectively, these efforts resulted in the deluge of information that helped the researchers to underpin the interface. The latest molecular biology techniques furnished novel detection methods for the anthracnose pathogen, refined the understanding of pathogen population dynamics, and provided the insights on co-evolutionary common bean resistance and C. lindemuthianum virulence dynamics. One of the important breakthroughs came when the Phaseolus vulgaris and its corresponding anthracnose pathogen (C. lindemuthianum) genomes were decoded in 2014 and 2017, respectively. Availability of both the genomes yielded a significant genomic information that helped bean communities to fine map the economically important traits and to identify the pathogenicity determinants and effector molecules. The interface is in a continuous development as knowledge of the anthracnose resistance genes, their precise physical locations, and the identification of effector proteins; the fungus arsenals are being routinely updated. Hence, we revisited the interface and tried to provide an overview of host pathogen dialogue in the genomic era. Additionally, we compiled the sporadic information on this pathosystem from India and provided its futuristic road map to shape its research in the world and northern India, the major dry bean area in the country.

Optimizing the Agrobacterium tumifaciens mediated transformation conditions in Colletotrichum lindemuthianum: A step forward to unravel the functions of pathogenicity arsenals

Colletotrichum lindemuthianum is a hemibiotrophic fungal pathogen that causes bean anthracnose and it is rated among the top 10 important diseases infecting beans. Currently our knowledge on molecular mechanisms underlying C. lindemuthianum pathogenesis is limited. About five pathogenicity genes have been identified in C. lindemuthianum using Restricted Enzyme Mediated Integration (REMI) and the transformation using Agroinfection has not been optimized. In this study, a series of experiments were conducted to optimize the key parameters affecting the Agrobacterium tumefaciens- mediated transformation (ATMT) for C. lindemuthianum. The transformation efficiency increased with increase in spore concentration and co-cultivation time. However, the optimum conditions that yielded significant number of transformants were 10⁶ ml^-1 spore concentration, co-cultivation time of 72 h, incubation at 25ºC and using a cellulose membrane filter for the co-cultivation. The optimized protocol resulted in establishment of large mutant library (2400). A few mutants were melanin deficient and a few were unable to produce conidia. To determine the altered pathogenicity, two new approaches such as detached leaf and twig techniques proved reliable and require fewer resources to screen the large mutant libraries in a short time. Among the 1200 transformants tested for virulence, 90% transformants were pathogenically similar to wild type (race 2047), 96 and 24 were reduced and impaired, respectively. The altered avirulent transformants can prove vital for understanding the missing link between growth and developmental stages of pathogen with virulence. This platform will help to develop strategies to determine the potential pathogenicity genes and to decipher molecular mechanisms of host-pathogen interactions in more detail.

North-Western Himalayan Common Beans: Population Structure and Mapping of Quantitative Anthracnose Resistance Through Genome Wide Association Study

Common bean (Phaseolus vulgaris L.) is an important legume crop of north-western (NW) Himalayan region and the major disease that causes catastrophic loss to the crop is anthracnose, which is caused by Colletotrichum lindemuthianum. The pathogen is highly diverse and most of the commercial cultivars are susceptible to different races prevalent in the region. The lack of information on the genomic regions associated with anthracnose resistance in NW Himalayan common bean population prompted us to dissect Quantitative Resistance Loci (QRLs) against major anthracnose races. In this study, 188 common bean landraces collected from NW region were screened against five important anthracnose races and 113 bean genotypes showed resistance to one or multiple races. Genotyping by sequencing (GBS) was performed on a panel of 192 bean lines (4 controls plus 188 Indian beans) and 22,589 SNPs were obtained that are evenly distributed. Population structure analysis of 192 bean genotypes categorized 188 Indian beans into two major clusters representing Andean and Mesoamerican gene pools with obvious admixtures. Many QRLs associated with anthracnose resistance to Indian C. lindemuthianum virulences (race 3, 87, and 503) are located at Pv04 within the gene models that encode typical resistance gene signatures. The QRLs associated with race 73 are located on Pv08 and overlaps with Co-4 anthracnose resistance gene. A SNP located at distal end of Pv11 in a gene model Phvul.011G202300 which encodes a LRR with a typical NB-ARC domain showed association with race 73 resistance. Common bean genomic regions located at Pv03, Pv09, and Pv11 showed association with resistance to anthracnose race 2047. The present study showed presence of many novel bean genomic regions associated with anthracnose resistance. The presence of Co-4 and Co-2 genes in our material is encouraging for breeding durable anthracnose resistant cultivars for the region.

Population structure of Venturia inaequalis, a hemibiotrophic fungus, under different host resistance specificities in the Kashmir valley

Venturia inaequalis is a notorious fungal pathogen and show classical gene for gene interaction with its apple host. Neutral markers provide clues about history, evolutionary potential, genetic diversity and population structure of V. inaequalis. The genetic diversity and population structure of fungus indicates that the pathogen is highly diverse with the capacity to breach the scab resistance genes. In the present study, we collected 108 V. inaequalis isolates from three apple cultivars differing in Rvi1 resistance gene. Based on the AMOVA, the variation was mostly distributed among the isolates, providing evidence of non-existence of subpopulation in orchards thus founder population is difficult to arise in Kashmir apple orchards. Pair wise genetic differentiation is less due to regular occurrence of gene flow between the populations residing on different orchard as infected material is transported without stringent quarantine measures. Based on principal coordinate analysis and clustering algorithm as implemented in STRUCTURE, we observed admixture between the two subpopulations, which is quite low, suggesting the existence of pre-zygotic and post-zygotic barriers to gene flow and we cannot rule out the existence of other structures shared by accessions belonging to different varieties. Due to the continuous increase in introduction and monoculture of apple varieties, mixed orchard with different host resistance specificities are more suitable for managing the apple scab in Kashmir valley.

Why I use both prospective randomized trials and registry data when choosing the personalized treatment of an AAA patient

Randomized controlled trials (RCTs) have been the core of level 1 data in medical and surgical science for at least the last three decades. However, frequently patient selection is very narrow, anatomic criteria do not match real-world experience, and much of the work is done in selected academic centers. We use RCTs to help explain the rational for intervention and then rely on longitudinal registries and single center data to give the patients a real-world expectation concerning outcomes and complications in our hands.

A comparison between methadone and buprenorphine for perioperative analgesia in dogs undergoing ovariohysterectomy

OBJECTIVE

To investigate whether preoperative methadone provides superior perioperative analgesia compared to buprenorphine in dogs undergoing ovariohysterectomy.

METHODS

Eighty female dogs were recruited to an assessor-blinded, randomised, clinical trial. Dogs received a premedication dose of 0·05 mg/kg acepromazine or 10 μg/kg medetomidine combined with either 0·3 mg/kg methadone or 20 μg/kg buprenorphine intramuscularly. Anaesthesia was induced with propofol and maintained with isoflurane. Pain was assessed using two scoring schemes (a dynamic interactive visual analogue scale and the short form of the Glasgow Composite Pain Scale) before premedication, 30 minutes later and every hour for 8 hours after premedication. If indicated, rescue analgesia was provided with methadone. Meloxicam was administered after the final assessment. The area under the curve for change in pain scores over time and the requirement for rescue analgesia were compared between groups.

RESULTS

Groups premedicated with buprenorphine had significantly higher pain scores than those premedicated with methadone. There was no interaction between opioid and sedative for any outcome measure. Rescue analgesia was required by significantly more dogs premedicated with buprenorphine (45%) than that of methadone (20%).

CLINICAL SIGNIFICANCE

At the doses investigated, methadone produced superior postoperative analgesia compared to buprenorphine in dogs undergoing ovariohysterectomy.

Carotid interventions (CEA and CAS) in acute stroke patients: which procedure on which patient

Treatment of carotid bifurcation disease in patients presenting with acute stroke has been a controversial issue over the past four decades. Classically, patients were asked to wait four to six weeks before intervention was entertained in order for the brain to stabilize and the risks of intervention to be minimized. Unfortunately, up to 20% of patients will have a secondary event after their index event and the window of opportunity to save, potentially salvageable ischemic tissue will be missed. Early reports had demonstrated poor results with intervention. However, more recently, institutions such as ours have demonstrated excellent result in early intervention in patients who present with stable mild to moderate stroke with an NIH stroke scale less than 15 and preferably less than 10, present with stroke and ipsilateral carotid artery lesion of 50% or greater. Also more recently, we have been aggressively treating patients with larger ulcerative plaques even if the stenosis approaches 50%. In our and others experiences, patients who are treated at institutions that have comprehensive stroke centers (CSCs) where they have a multidisciplinary system that consists of vascular surgeons, neuro interventionalists, stroke neurologists, specifically trained stroke nursing staff and a neuro intensive ICU have had optimal results. Early assessment, diagnosis of stroke with recognition of cause of embolization is mandatory but patient selection is extremely important; finding those patients who will benefit the most from urgent intervention. Most studies have demonstrated the benefit of carotid endarterectomy in these patients. More recent studies have demonstrated acceptable results with carotid stenting, especially in smaller lesions, those less than 1.2 centimeters. Early intervention should be avoided in most patients who are obtunded or with an NIH stroke scale greater than 15 or who do not have any "brain at risk" to salvage. These patients may be better served by being treated medically than those small group of patients that do have some improvement may benefit from interval intervention.

The applied physiology of cough

The cough reflex is such an important defense mechanism of the respiratory tract that a thorough knowledge of its applied physiology in respiratory disease is essential for clinicians. It is a well-integrated reflex, which has afferent limb consisting of receptors and afferent nerves, the central cough center in the brainstem and the efferent limb consisting of motor nerves supplying the muscles of coughing. The cough process consists of inspiratory phase, compressive phase and expiratory phase. Stimuli that can initiate the cough process can be central or peripheral in the lungs or outside the lungs. The important function of the cough reflex is to maintain the airways and alveoli clear and healthy. The mechanisms by which it achieves this are (i) high velocity of expiratory gas flows produced in the expiratory phase (ii) the compression of the lungs and airways by high positive pleural pressure generated in the compressive phase. Cough threshold can be determined by giving acetic acid, citric acid or capsaicin inhalation challenge test. This has practical application in clinical research. The pathophysiological basis of different types of cough encountered in clinical practice is discussed.

Effects of an aqueous extract of processed bidi tobacco on the growth of hamster tracheal epithelial cells

Inhalation of tobacco dust is responsible for elevated genotoxicity and pulmonary ailments in workers engaged in processing tobacco for the manufacture of bidis, the Indian version of cigarettes. Tracheal tissue being the major site of interaction with tobacco dust, the effects of different concentrations of an aqueous extract of bidi tobacco (ATE) on the growth of a hamster tracheal epithelial cell line (HTE) were investigated. Colony forming efficiency assay revealed that ATE was cytotoxic only at the highest concentration of 5.0 mg/ml. In cultures treated with 1.25 mg/ml ATE, the cell doubling time and growth rate were similar to that of the controls, while a significant increase in cell doubling time (29.4+/-0.3 h vs 14.0+/-3.75 h, P<0.001) was observed at 2.5 mg/ml ATE concentration. Exposure of HTE cells to the non-toxic ATE concentration of 2.5 mg/ml was found to stimulate ornithine decarboxylase (ODC) activity, incorporation of [3H] methyl thymidine into DNA and increase in the S phase fraction was seen by flow cytometry. However, a 56% reduction in the growth rate of cultures treated with 2.5 mg/ml ATE was related to the prolongation of the traverse of cells through S phase. ATE-induced growth suppression was reversed when cultures were grown in ATE-free medium or upon repeated exposure to ATE. The findings suggest that increased tracheal cell proliferation induced by chronic inhalation of tobacco dust may contribute to the development of pulmonary disorders and possibly neoplasia in exposed individuals.

Childhood asthma--office management

Childhood asthma is a major problem in office practice. For an acute life threatening attack (which is indicated by presence of severe distress, pulsus paradoxus, oxygen saturation less than 93%, cyanosis, peak expiratory flow rate of less than 50% of predicted) child should be directly admitted in intensive care unit. If it is a non life threatening attack the child can be managed in the office. Initially, the child should be given b2 agonists by inhalation route with either metered dose inhaler (MDI), MDI with spacer or nebuliser. It there is severe bronchospasm or inhalation therapy is not possible then epinephrine of b2 agonists may be given subcutaneously. The medications can be repeated 2-3 times. If response is adequate the child may be sent home on b2 agonist by oral or inhalation route at an interval of 406 hours. In case of inadequate response the child is started on oral or parenteral corticosteroids. Even after steroids if inadequate response the child is started on intravenous theophylline. Once the acute exacerbation is controlled the child is assessed for starting maintenance therapy. For this purpose his illness is graded from stage I to V depending on the severity. For stage I and II b2 agonists are prescribed as and when required. For stage III sodium cromoglycate by inhalation should be prescribed. For stage IV inhalation steroids in usual doses and for stage V inhalation steroids in higher doses are prescribed along with a minimum dose of oral steroids is added. For symptomatic control slow release theophylline or long acting b2 agonists may be added along with maintenance therapy as and when required. Apart from medications a proper education of parents and patients is necessary to improve the outcome of asthma by increasing the compliance and better control of environment.

Pulmonary hypertension associated with portal hypertension in a child with Williams syndrome--a case report

A 14-year-old white female with Williams syndrome and portal hypertension presented in shock; at autopsy she was found to have grade II to VI vascular changes of pulmonary hypertension. This case demonstrates the association of portal hypertension and pulmonary hypertension in a pediatric patient.

Endoscopic balloon dilation of esophageal strictures in children

A total of 17 patients, ages 3 weeks to 14 1/2 years, had 20 esophageal strictures develop after repair of esophageal atresia (9 strictures); primary gastroesophageal reflux (3 strictures); Nissen fundoplication (4 strictures); epidermolysis bullosa congenita dystrophica (1 stricture); congenital esophageal stenosis (2 strictures); or colonic interposition (1 stricture). These strictures were treated with 132 endoscopic balloon catheter dilations (average, 6.6/patient, range, 1 to 24) during a period of 42 months (average, 8 months; range, 2 to 42 months). Fifteen of the 17 patients are now asymptomatic. Thirteen of the 17 patients had documented reflux esophagitis and were also medically treated. The two residually symptomatic patients included a patient with severe proximal esophagitis secondary to epidermolysis bullosa congenita dystrophica who had only a temporary response to dilations and another patient with a tight Nissen fundoplication who did not improve after dilation but is now asymptomatic after corrective surgery. The 10 patients with tracheoesophageal fistula repair were asymptomatic within 3 to 21 months (average, 10.8 months). Only one patient had perforation develop as a result of the procedure. Sixteen of 17 patients had the procedures performed as outpatients. All patients were given oral feedings throughout the course of dilation and had normal growth.

Malignant hypertension due to reflux nephropathy in an adolescent (a case report)

Malignant hypertension in an adolescent due to reflux nephropathy (RN) is rare. Here we are presenting such a case unassociated with the usual symptoms of hypertension. The problems of diagnosis, management, prognosis and prevention of RN are discussed with a review of relevant literature.

Congenital intermittent atrio-ventricular dissociation in tetralogy of Fallot (a case report)

A case of tetralogy of fallot with congenital intermittent atrioventricular dissociation is reported. A review of standard postgraduate books of cardiology fails to describe this condition, thus showing its extreme rarity. The therapeutic dilemma in treating such a case is also discussed.

Congenital lipodystrophy with defective leucocyte function (a case report)

A 6 1/2 year old female child with congenital lipodystrophy is being presented. The noteworthy feature in this case was the defective leucocyte function and its association with tuberculous pericardial effusion.

Enzyme-linked immuno-assay for the detection of mycobacterium tuberculosis specific IgG antibody in the cerebrospinal fluid in cases of tuberculous meningitis

The efficacy of enzyme-linked immuno-assay in the detection of IgG antibody against mycobacterium tuberculosis in the cerebrospinal fluid of patients suffering from tuberculous meningitis was measured in 50 children consecutively admitted to hospital. The controls were 15 cases of tuberculosis other than of the central nervous system; 24 cases of pyogenic meningitis; 19 cases of neurologic problems but with essentially normal cerebrospinal fluid. The specificity of the test ranged from 93 to 100 per cent and the sensitivity from 82 to 95 per cent.

Study of EEG and CT scan in neurologically normal cases of focal convulsions

Twenty-three neurologically normal children with focal convulsions were studied with EEG and CT scan. Thirty-five per cent had an abnormal CT scan. Lesions of potential therapeutic significance were seen in 30 per cent of all scans. Abnormalities detected on CT scans were as follows: tuberculomas, five cases; acute infarct, one case; gliosis, one case; multiple cortical cysts, one case. All the cases with intracranial tuberculomas were aged more than 5 years. A good correlation was found between the EEG and the CT scan findings. Maximum percentage (57 per cent) of CT scan abnormality was seen in cases exhibiting focal abnormality on EEG and minimum percentage in those with a normal EEG (18 per cent).

Late hemorrhagic disease of infancy

Over a period of 1 1/2 years, 9 infants ages ranging between 3 weeks and 7 months presented with the syndrome of late hemorrhagic disease related to vitamin K deficiency. All were exclusively breast fed and had not received vitamin K at birth. Four of these had acute intracranial hemorrhage, of which 2 expired and the surviving 2 have residual neurologic handicap. Of the remaining 5 who had skin and mucosal bleeds, all recovered on administration of vitamin K.

Crosscultural differences in frontalis muscle tension levels: an exploratory study comparing Japanese and Westerners

This paper describes a comparison between Japanese (N = 20) and Westerners (N = 20) in their respective frontal EMG levels and their ability to relax during one 5-minute biofeedback training session. The data indicated a significantly lower baseline muscle tension level in Japanese than in Westerners. After EMG biofeedback, however, no significant difference was found between the two groups. Japanese females showed significantly higher tension levels both during baseline and biofeedback phases than did japanese males.

Comparison of intramuscular and intravenous succinylcholine on intraocular pressure

The effect of succinylcholine on intraocular pressure was determined in one group of patients who received the drug intravenously, compared with a similar group receiving the drug intramuscularly. The group receiving intravenous succinylcholine showed a significantly earlier rise in pressure and a significantly higher rise in pressure compared to the group receiving the drug intramuscularly. In both groups the pressure returned to normal within five minutes. It is suggested that in cases with a ruptured globe or wound leak in which succinylcholine is used to facilitate tracheal intubation, the drug should be administered intramuscularly.