System of wheat intensification (SWI): Effects on lodging resistance, photosynthetic efficiency, soil biomes, and water productivity

Intense cultivation with narrow row spacing in wheat, a common practice in the Indo-Gangetic plains of South Asia, renders the crop more susceptible to lodging during physiological maturity. This susceptibility, compounded by the use of traditional crop cultivars, has led to a substantial decline in overall crop productivity. In response to these challenges, a two-year field study on the system of wheat intensification (SWI) was conducted. The study involved three different cultivation methods in horizontal plots and four wheat genotypes in vertical plots, organized in a strip plot design. Our results exhibited that adoption of SWI at 20 cm × 20 cm resulted in significantly higher intercellular CO2 concentration (5.9-6.3%), transpiration rate (13.2-15.8%), stomatal conductance (55-59%), net photosynthetic rate (126-160%), and photosynthetically active radiation (PAR) interception (1.6-25.2%) over the existing conventional method (plant geometry 22.5 cm × continuous plant to plant spacing) of wheat cultivation. The lodging resistance capacity of both the lower and upper 3rd nodes was significantly higher in the SWI compared to other cultivation methods. Among different genotypes, HD 2967 demonstrated the highest recorded value for lodging resistance capacity, followed by HD 2851, HD 3086, and HD 2894. In addition, adoption of the SWI at 20 cm × 20 cm enhanced crop grain yield by 36.9-41.6%, and biological yield by 27.5-29.8%. Significantly higher soil dehydrogenase activity (12.06 μg TPF g-1 soil hr-1), arylsulfatase activity (82.8 μg p-nitro phenol g-1 soil hr-1), alkaline phosphatase activity (3.11 n moles ethylene g-1 soil hr-1), total polysaccharides, soil microbial biomass carbon, and soil chlorophyll content were also noted under SWI over conventional method of the production. Further, increased root volumes, surface root density and higher NPK uptake were recorded under SWI at 20×20 cm in comparison to rest of the treatments. Among the tested wheat genotypes, HD-2967 and HD-3086 had demonstrated notable increases in grain and biological yields, as well as improvements in the photosynthetically active radiation (PAR) and chlorophyll content. Therefore, adoption of SWI at 20 cm ×20 cm (square planting) with cultivars HD 2967 might be the best strategy for enhancing crop productivity and resource-use efficiency under the similar wheat growing conditions of India and similar agro-ecotypes of the globe.

First report of association of 'Candidatus Phytoplasma asteris' with Moringa oleifera leaf yellowing and stunting disease in India

Moringa oleifera (family Moringaceae) also known as the 'drumstick tree' is a significant nutritious and medicinal plant that is commonly grown in India and contains a variety of vital phytochemicals. M. oleifera is used in several Indian herbal medicine formulations to treat a variety of illnesses (Kumar and Rao 2021). Typical phytoplasma symptoms of leaf yellowing and stunting were observed in M. oleifera trees up to 10% incidence at Acharya Narendra Dev University of Agriculture & Technology, Ayodhya, Uttar Pradesh, India in November 2021 and stunting with less fruit bearings symptoms with 8% incidence in October 2021 at Jonnalakothapalle village of Mudigubba mandal of Ananthapuramu district in Andhra Pradesh, India (Fig.1a, b). To investigate the possibility of a phytoplasma association with the symptoms, total DNA was isolated from the leaf samples collected from two diseased and two healthy plants from both the locations using CTAB method. The DNAs isolated were analysed by nested polymerase chain reaction (PCR) with universal phytoplasma primer pairs P1/P7 and R16F2n/R16R2 for the 16S rRNA gene (Deng and Hiruki 1991; Gundersen and Lee 1996) and secAfor1/sArev3 and SecAfor2/ SecArev3 for secA gene (Hodgetts et al. 2008). Amplicons of the expected size (~1.25kb from 16S rRNA gene and ~480bp from secA gene) were obtained from symptomatic plants only. The nested PCR products were cloned (pGEM-T Easy Vector, Promega), sequenced (ABA Biotech, India) and the sequences were deposited in GenBank with accession numbers OP358449, OP358450, OP358451, OP358452 for the 16SrRNA gene (~1.25 kb) and OP358443, OP358444, OP358445, OP358446 for the secA gene (~480 bp). BLASTn analysis revealed that the partial 16S rRNA gene sequences of M. oleifera phytoplasma isolate shared up to 99.9% sequence identity with the strain 'Candidatus Phytoplasma asteris' (Accession numbers MN909051, MN909047) and secA gene sequences shared up to 100% sequence identity with 'Ca. Phytoplasma asteris' (Accession numbers KJ434315, KJ462009) belonging to 16SrI group. The 16S rRNA and secA genes sequence-based phylogenetic analysis (Figure 1d,e) showed that the phytoplasma strain associated with M. oleifera leaf yellowing and stunting clustered within the 16SrI phytoplasma group closest to 16SrI-B ('Ca. P. asteris') subgroup strains. Furthermore, the virtual RFLP pattern derived from the query 16S rDNA F2nR2 fragment is identical (similarity coefficient 1.00) to the reference pattern of 16Sr group I, subgroup B (GenBank accession: AP006628). To the best of our knowledge, this is the first report of the 16SrI-B subgroup of the phytoplasma strains with M. oleifera in the world. 'Candidatus Phytoplasma asteris' (16SrI-B subgroup) strains have been reported from several other commercial crops and weed hosts in India and efficient leafhopper vectors have been identified (Rao 2021; Reddy 2021). This indicates that the 'Ca. P. asteris'-related strains (16SrI-B) are widespread and infecting several plant species in India. The increasing incidence of the 16SrI-B strain and its wide host range in India strongly suggests further research into the epidemiology involved in the dynamic spread of the disease in order to recommend a suitable management approach.

Emerging innovations in cold plasma therapy against cancer: A paradigm shift

Cancer is one of the major causes of mortality, accounting for ∼ 9.5 million deaths globally in 2018. The spectrum of conventional treatment for cancer includes surgery, chemotherapy and radiotherapy. Recently, cold plasma therapy surfaced as a novel technique in the treatment of cancer. The FDA approval of the first trial for the use of cold atmospheric plasma (CAP) in cancer therapy in 2019 is evidence of this. This review highlights the mechanisms of action of CAP. Additionally, its applications in anticancer therapy have been reviewed. In summary, this article will introduce the readers to the exciting field of plasma oncology and help them understand the current status and prospects of plasma oncology.

Fabrication of chitosan/alginate/hydroxyapatite hybrid scaffolds using 3D printing and impregnating techniques for potential cartilage regeneration

Three-dimensional (3D) printed hydrogel scaffolds enhanced with ceramics have shown potential applications for cartilage regeneration, but leaving biological and mechanical properties to be desired. This paper presents our study on the development of chitosan /alginate scaffolds with nano hydroxyapatite (nHA) by combining 3D printing and impregnating techniques, forming a hybrid, yet novel, structure of scaffolds for potential cartilage regeneration. First, we incorporated nHA into chitosan scaffold printing and studied the printability by examining the difference between the printed scaffolds and their designs. Then, we impregnated alginate with nHA into the printed chitosan scaffolds to forming a hybrid structure of scaffolds; and then characterized the scaffolds mechanically and biologically, with a focus on identifying the influence of nHA and alginate for potential cartilage regeneration. The results of compression tests on the scaffolds showed that the inclusion of nHA increased the elastic moduli of scaffolds; while the live/dead assay illustrated that nHA had a great effect on improving attachment and viability of ATCD5 cells on the scaffolds. Also, our results illustrated scaffolds with nHA impregnated in alginate hydrogel enhanced the cell viability and attachment. Furthermore, antibacterial activity of hybrid scaffolds was characterized with results indicating that the chitosan scaffolds had favourable antibacterial ability, which was further enhanced with the impregnated nHA. Taken together, our study has illustrated that chitosan/HA/alginate hybrid scaffolds are promising for cartilage regeneration and the methods developed to create hybrid scaffolds based on 3D printing and impregnating techniques, which can also be extended to fabricating scaffolds for other tissue engineering applications.

Sexing chickens (Gallus gallus domesticus) with high-resolution melting analysis using feather crude DNA

Identification of sex in broiler chickens allows researchers to reduce the level of variation in an experiment caused by the sex effect. Broiler breeds commonly used in research are no longer feather sexable because of the change in their genetics. Other alternate sexing methods are costly and difficult to apply on a large scale. Therefore, a sexing method is required that is both cost effective and highly sensitive as well as having the ability to offer high throughput genotyping. In this study, high-resolution melting (HRM) analysis was used to detect DNA variations present in the gene chromodomain helicase DNA binding 1 protein (CHD1) on the Z and W chromosomes (CHD1Z and CHD1W, respectively) of chickens. In addition, a simplified DNA extraction protocol, which made use of the basal part of chicken feathers, was developed to speed up the sexing procedure. Three pairs of primers, that is, CHD1UNEHRM1F/R, CHD1UNEHRM2F/R, and CHD1UNEHRM3F/R, flanking the polymorphic regions between CHD1Z and CHD1W were used to differentiate male and female chickens via distinct melting curves, typical of homozygous or heterozygous genotypes. The assay was validated by the HRM-sexing of 1,318 broiler chicks and verified by examining the sex of the birds after dissection. This method allows for the sexing of birds within a couple of days, which makes it applicable for use on a large scale such as in nutritional experiments.

A novel leaf rust resistance gene introgressed from Aegilops markgrafii maps on chromosome arm 2AS of wheat

A novel leaf rust resistance gene, LrM, introgressed from Aegilops markgrafii and mapped on chromosome 2AS using SSR- and SNP-based PCR markers will aid in broadening the genetic base of rust resistance in wheat. A new leaf rust resistance gene tentatively named LrM was introgressed from the diploid non-progenitor species Ae. markgrafii (2n = 2x = 14, genome CC) into common wheat using the nulli-5B mechanism. The introgression line ER9-700 showed a high degree of resistance against a wide spectrum of Puccinia triticina pathotypes. Genetic analysis was performed using the F₁, F₂, F_2:3 and BC₁F₁ generations derived from the cross ER9-700/Agra Local. The results showed a single dominant gene for leaf rust resistance. The resistance gene LrM was mapped on chromosome arm 2AS using SSR- and SNP-based PCR markers. Preliminary mapping with SSR markers in the F_2:3 population from the cross ER9-700/Agra Local identified two SSR markers flanking the LrM. SNPs were identified in the genomic region flanked by SSR markers, and SNP-based PCR markers were developed to construct the final map. Three SNP-based PCR markers co-segregated and mapped closest to the resistance gene at a distance of 2 cM. The gene LrM was distinguished from all the other genes designated and mapped on chromosome arm 2AS by molecular markers and rust reaction. All five markers used in the mapping amplified identical alleles in the donor Ae. markgrafii accession and introgression line ER9-700. The chromosomal location and rust reaction suggest that LrM is a novel leaf rust resistance gene that may be useful in broadening the genetic base of leaf rust resistance in wheat.

Assessment of Elastic-Plastic Fracture Behavior of Cortical Bone Using a Small Punch Testing Technique

The fracture properties of cortical bone are directly coupled to its complex hierarchical structure. The limited availability of bone material from many anatomic locations creates challenges for assessing the effect of bone heterogeneity and anisotropy on fracture properties. The small punch technique was employed to examine the fracture behavior of cortical bone in terms of area under the curve values obtained from load-load point displacement behavior. Fracture toughness of cortical bone was also determined in terms of J-toughness values obtained using a compact tension (CT) test. Area under the curve values obtained from the small punch test were correlated with the J-toughness values of cortical bone. The effects of bone density and compositional parameters on area under the curve and Jtoughness values were also analyzed using linear and multiple regression analysis. Area under the curve and J-toughness values are strongly and positively correlated. Bone density and %mineral content are positively correlated with both area under the curve and J-toughness values. The multiple regression analysis outcomes support these results. Overall, the findings support the hypothesis that area under the curve values obtained from small punch tests can be used to assess the fracture behavior of cortical bone.

Predicting the Dose of Warfarin for Therapeutic Anticoagulation

The validity of a previously described technique for predicting warfarin requirements based on the anticoagulant response to a fixed loading dose was assessed prospectively in 57 patients. There was a close relationship between the predicted and initially observed daily warfarin dose required to maintain the patient within the therapeutic range for anticoagulation. The significant relationship between predicted and observed maintenance dose persisted at 4 and 12 weeks although it decreased with increasing time.

The relationship between observed and predicted maintenance requirement of warfarin was not affected by the concomitant use of intermittent intravenous injections of heparin when 9 hr was allowed to elapse between the previous dose of heparin and the thrombotest estimation on which the prediction was based.

It is concluded that the method is valuable in predicting an individual’s warfarin requirement, although it does not obviate the need for regular monitoring of anticoagulant control.

Inflammasome gene profile is modulated in septic patients, with a greater magnitude in non-survivors

Inflammasome signalling induces the processing and secretion of interleukin (IL)-1β and IL-18 which, coupled with pyroptosis, activate further the inflammatory response. In the present study we evaluated the expression of genes involved in inflammasome signalling pathways in septic patients, their interaction networks and the predicted functions modulated in survivors and non-survivors. Twenty-seven patients with sepsis secondary to community-acquired pneumonia admitted to intensive care units from three general hospitals in São Paulo were included into the study. We performed a polymerase chain reaction (PCR) array encompassing 35 genes related to the nucleotide-binding oligomerization domain and leucine-rich repeat-containing (NLR)-inflammasome in peripheral blood mononuclear cells obtained at admission and after 7 days of follow-up. Eleven healthy volunteers were used as the reference group. Increased NLRC4 and NLRP3 and decreased nucleotide-binding oligomerization domain (NOD1), and NLRP1 expression was observed in septic patients compared to healthy individuals; the IL-1β and IL-18 expression levels were also high in the patients. The gene expression changes followed the same patterns in surviving and non-surviving patients, with higher magnitudes observed in non-survivors. Functional analyses revealed, however, that activation and inhibition intensity for representing functions were different in survivors and non-survivors, as for production of reactive oxygen species, synthesis of nitric oxide and for the control of bacterial infections. Our results showed that the genes involved in the activation of the NLR-inflammasome cascades were altered substantially in septic patients, with a higher number of altered genes and a higher intensity in the disturbance of gene expression found among patients dying of sepsis.

Morpho-histological and ultra architectural changes during early development of endangered golden mahseer Tor putitora

Ultrastructural and histological changes in the embryonic and larval surface during ontogenesis of the endangered golden mahseer Tor putitora is studied here for the first time. Embryonic development was completed 91-92 h after fertilization at an ambient temperature of 23° ± 1° C (mean ± s.d.). The gastrula stage was characterized by presence of the Kupffer's vesicle, notochord, ectoderm and endoderm cells. Primordial germ cells were clearly identifiable from c. 55 h post-fertilization at the organogenesis stage. Mean total length of newly hatched larvae was 7·0 ± 0·5 mm. Scanning electron microscopy of newly hatched larvae demonstrated vitelline arteries, microridged epithelial cells and mucous gland openings over much of the body surface. Eye, oral cavity, pharyngeal arches, heart, intestinal loop, prosencephalon, cephalic vesicle and nasal epithelium were clearly distinguished in 3 day old hatched individuals. In 6 day old individuals, caudal-fin rays and internal organs were evident. The dorsal fin became prominent at this stage and larvae began swimming at the surface. The reserved yolk material was totally absorbed 8-11 days after hatching and larvae began feeding exogenously. Tor putitora exhibited a longer early developmental period than other cyprinids reared at similar temperatures.

Economics, energy, and environmental assessment of diversified crop rotations in sub-Himalayas of India

Reducing the carbon footprint and increasing energy use efficiency of crop rotations are the two most important sustainability issues of the modern agriculture. Present study was undertaken to assess economics, energy, and environmental parameters of common diversified crop rotations (maize-tomato, and maize-toria-wheat) vis-a-vis traditional crop rotations like maize-wheat, maize + ginger and rice-wheat of the north-western Himalayan region of India. Results revealed that maize-tomato and maize + ginger crop rotations being on par with each other produced significantly higher system productivity in terms of maize equivalent yield (30.2-36.2 t/ha) than other crop rotations (5.04-7.68 t/ha). But interestingly in terms of energy efficiencies, traditional maize-wheat system (energy efficiency 7.9, human energy profitability of 177.8 and energy profitability of 6.9 MJ/ha) was significantly superior over other systems. Maize + ginger rotation showed greater competitive advantage over other rotations because of less consumption of non-renewable energy resources. Similarly, maize-tomato rotation had ability of the production process to exploit natural resources due to 14-38% less use of commercial or purchased energy sources over other crop rotations. Vegetable-based crop rotations (maize + ginger and maize-tomato) maintained significantly the least carbon footprint (0.008 and 0.019 kg CO2 eq./kg grain, respectively) and the highest profitability (154,322 and 274,161 Rs./ha net return, respectively) over other crop rotations. As the greatest inputs of energy and carbon across the five crop rotations were nitrogen fertilizer (15-29% and 17-28%, respectively), diesel (14-24% and 8-19%, respectively) and irrigation (10-27% and 11-44%, respectively), therefore, alternative sources like organic farming, conservation agriculture practices, soil and water conservation measures, rain water harvesting etc. should be encouraged to reduce dependency of direct energy and external carbon inputs particularly in sub-Himalayas of India.

Novice lifters exhibit a more kyphotic lifting posture than experienced lifters in straight-leg lifting

As torso flexion and repetitive lifting are known risk factors for low back pain and injury, it is important to investigate lifting techniques that might reduce injury during repetitive lifting. By normalizing lumbar posture to a subject's range of motion (ROM), as a function of torso flexion, this research examined when subjects approached their range of motion limits during dynamic lifting tasks. For this study, it was hypothesized that experienced lifters would maintain a more neutral lumbar angle relative to their range of motion, while novice lifters would approach the limits of their lumbar ROM during the extension phase of a straight-leg lift. The results show a statistically significant difference in lifting patterns for these two groups supporting this hypothesis. The novice group maintained a much more kyphotic lumbar angle for both the flexion (74% of the lumbar angle ROM) and extension phases (86% of the lumbar angle ROM) of the lifting cycle, while the experienced group retained a more neutral curvature throughout the entire lifting cycle (37% of lumbar angle ROM in flexion and 48% of lumbar angle ROM in extension). By approaching the limits of their range of motion, the novice lifters could be at greater risk of injury by placing greater loads on the supporting soft tissues of the spine. Future research should examine whether training subjects to assume more neutral postures during lifting could indeed lower injury risks.

Adipose tissue gene expression and metabolic health of obese adults

Obese subjects with a similar body mass index (BMI) exhibit substantial heterogeneity in gluco- and cardiometabolic heath phenotypes. However, defining genes that underlie the heterogeneity of metabolic features among obese individuals and determining metabolically healthy and unhealthy phenotypes remain challenging. We conducted unsupervised hierarchical clustering analysis of subcutaneous adipose tissue transcripts from 30 obese men and women ⩾40 years old. Despite similar BMIs in all subjects, we found two distinct subgroups, one metabolically healthy (group 1) and one metabolically unhealthy (group 2). Subjects in group 2 showed significantly higher total cholesterol (P=0.005), low-density lipoprotein cholesterol (P=0.006), 2-h insulin during oral glucose tolerance test (P=0.015) and lower insulin sensitivity (SI, P=0.029) compared with group 1. We identified significant upregulation of 141 genes (for example, MMP9 and SPP1) and downregulation of 17 genes (for example, NDRG4 and GINS3) in group 2 subjects. Intriguingly, these differentially expressed transcripts were enriched for genes involved in cardiovascular disease-related processes (P=2.81 × 10(-11)-3.74 × 10(-02)) and pathways involved in immune and inflammatory response (P=8.32 × 10(-5)-0.04). Two downregulated genes, NDRG4 and GINS3, have been located in a genomic interval associated with cardiac repolarization in published GWASs and zebra fish knockout models. Our study provides evidence that perturbations in the adipose tissue gene expression network are important in defining metabolic health in obese subjects.

Cystic acoustic neuromas

Predominantly cystic acoustic neuromas are rare and they usually present with clinical and radiological features different from their more common solid counterparts. Two cases of cystic acoustic neuromas are reported here.

Soluble VEGFR1 (sVEGFR1) as a novel marker of amyotrophic lateral sclerosis (ALS) in the North Indian ALS patients

BACKGROUND AND PURPOSE

  North Indian patients with amyotrophic lateral sclerosis (ALS) exhibit substantially extended survival time after onset of the disease as compared to their Western counterparts. Earlier, we found that vascular endothelial growth factor-A (VEGF-A) may be associated with increased survival of these patients. We now measured soluble vascular endothelial growth factor receptor-1 (sVEGFR1), an inhibitor receptor for VEGF-A, in these patients with ALS.

METHODS

Patients with sporadic ALS (n = 36) attending the Neurology Outpatient at Post Graduate Institute of Medical Education and Research (PGIMER) at Chandigarh were included on the basis of El Escorial criteria. The sVEGFR1 levels were analyzed in serum of these patients using enzyme-linked immunosorbent assay (ELISA) and compared with normal controls (n = 36).

RESULTS

  Soluble vascular endothelial growth factor receptor-1 was found to be decreased significantly in serum of patients with ALS. Serum obtained from definite ALS revealed significantly lower sVEGFR1 as compared to probable ALS. However, there was no difference in serum sVEGFR1 levels between male and female patients with ALS.

CONCLUSIONS

Soluble vascular endothelial growth factor receptor-1 downregulation may result in increased serum VEGF-A reported previously in our patients with ALS and may indicate the activation of compensatory mechanism in response to neurodegeneration. The lower serum sVEGFR1 levels may have a possible clinicopathological association, if not causal, to the extended survival of North Indian patients with ALS; however, the result needs further investigations particularly in comparable Caucasian ALS population.

Presumed infectious endophthalmitis following cataract surgery in the UK: a case–control study of risk factors

AIMS

To study risk factors for presumed infectious endophthalmitis complicating cataract surgery in the United Kingdom.

METHODS

Two hundred and fourteen clinically diagnosed patients with presumed infectious endophthalmitis were compared with 445 control patients throughout the United Kingdom in a prospective case-control study. The cases were identified through the British Ophthalmological Surveillance Unit reporting card system. Control patients undergoing cataract surgery from 13 'control centres' throughout the United Kingdom were selected randomly. Risk factors were identified by univariate and multivariate logistic regression analyses. Pertinent variables relating to the cataract extraction procedure, antimicrobial prophylaxis, ophthalmic and medical history were analysed with regard to postoperative infection.

RESULTS

Statistically significant risk factors in the multivariate model included inpatient cataract surgery (P=0.001), surgery in dedicated eye theatres (P<0.001), consultant grade surgeon (compared to registrar) (P=0.001), posterior capsule tear during cataract surgery (P=0.001). The use of face masks by the scrub nurse and surgeon during cataract surgery (P<0.001) and the administration of subconjunctival antibiotics at the end of surgery (P<0.001) were protective against postoperative infection.

CONCLUSIONS

In order to minimise the risk of postoperative endophthalmitis we would recommend the wearing of face masks by the surgeon and scrub nurse during cataract surgery and subconjunctival antibiotics at the end of surgery.

Phosphate metabolism in the cyanobacterium Anabaena doliolum under salt stress

In the present study, we have investigated the effects of NaCl concentrations on the growth and phosphate metabolism of an Anabaena doliolum strain isolated from a paddy field, in order to determine the possible effects of salinization. Growth rate, chlorophyll content, and protein content decreased with increasing salt concentration in the growth medium, while carbohydrate concentration increased. Phosphate content and phosphate uptake rate decreased. There was an increase in total alkaline phosphatase activity, with an approximately 7-fold increase in extracellular activity compensating for an approximately 3-fold decrease in cell-bound activity. NaCl effects on protein and chlorophyll concentrations were greater in P-deficient medium, while presence or absence of P in the medium had little effect on cellular carbohydrate concentrations. It is concluded that growth in high salt likely leads to reduced phosphate uptake in A. doliolum.

Transmission of -ray-induced unstable chromosomal aberrations through successive mitotic divisions in human lymphocytes in vitro

Transmission of unstable chromosomal aberrations through successive mitotic divisions M1-M4 was analysed in 3 Gy gamma-ray-irradiated G0 human lymphocytes in vitro, harvested at 50, 72 and 96 h. Bromodeoxyuridine (BrdU) incorporation and subsequently the fluorescence plus Giemsa (FPG) method allowed the cell cycle status of each cell scored to be ascertained. Higher dicentric frequencies were observed in cells within the same post-irradiation division derived from extended culture times, indicating either a delay in cell cycle progression of aberrant cells or different lymphocyte sub-populations. The yield of complete dicentrics decreased by a factor of two in passing from M1 to M2 and showed further reductions of 26 and 44%, respectively, in moving from M2 to M3 and from M3 to M4. In the case of conventionally stained metaphases, wherein the cell cycle status does not enter the picture, the dicentric frequencies showed a reduction in yield of 39.6% at 72 h and 52.1% at 96 h compared with 50 h, because the cells analysed comprise a mixture of metaphases in different cell cycles. In the FPG stained first division metaphases, 92-100% of dicentrics analysed at 50, 72 and 96 h and in the conventionally stained metaphases, 90-94, 72-84 and 54-80% of dicentrics analysed at 50, 72 and 96 h respectively were complete dicentrics (with fragments). In the M1, M2, M3 and M4 metaphases analysed, 92-100, 50-89, 20-70 and 10-50% of dicentrics, respectively, were complete dicentrics and 55-75, 53-68, 43-57 and 36-50% excess acentrics, respectively, were seen in cells with complete dicentrics. Interindividual variation was observed in cell cycle kinetics, radiation-induced chromosomal aberrations and micronucleus frequencies. A salient feature of the delayed effects was the induction of giant cells and the mirror dicentrics observed in them. The reduction in dicentric frequencies due to either cell cycle delay or cell death in successive generations is aided by the multiplicity of aberrations. Bridge-breakage-fusion (BBF) events mediated by dicentric chromosomes may also be instrumental in the perpetuation of chromosomal instability.

Ascorbic acid potentiates mitomycin C-induced micronuclei and sister chromatid exchanges in human peripheral blood lymphocytes in vitro

Vitamin C (l-ascorbic acid), an effective free radical scavenger present as ascorbate in most biological systems, is one of the most extensively studied antioxidant vitamins. Vitamin C acts as either a free radical scavenger or a pro-oxidant producing hydrogen peroxide and free radicals. The modulatory effect of L-ascorbic acid (AA) on Mitomycin C (MMC) induced chromosome damage has been evaluated in human peripheral blood lymphocytes in vitro. The effect of L-ascorbic acid, 200 microg/ml as 1- and 2-h pretreatment on the frequencies of the biomarkers micronuclei (MN), sister chromatid exchanges (SCEs), and chromosome aberrations (CA) induced by mitomycin C 0.1 and 0.2 microg/ml has been studied. AA pretreatment caused a statistically significant increase in MMC-induced MN and SCE frequencies for all treatment groups, but did not show an increase in induced chromosome aberrations compared to MMC treatment alone. Cell division delays caused by MMC was reversed in the presence of AA. Interindividual variability in MMC as well as AA plus MMC-induced MN, SCE, and CA frequencies were evident. Ascorbic acid potentiated MMC-induced chromosome damage in human lymphocytes in vitro. The potentiation observed has to be viewed in the light of metal ion catalysed autooxidation of AA in oxygenated media and the existence of an antioxidant system in vivo that inactivates oxyradicals before their interaction with DNA.

Primary spinal extradural hydatid cyst

We report a rare case of spinal cord compression caused by primary multiple extradural hydatid cysts.

Posterior fossa oligodendroglioma

Oligodendroglioma are the tumors of glial cells. They are rare in children and are more common in the cerebral hemispheres. A rare case of infratentorial oligodendroglioma in a female child is being reported here.

Clinical performance of a compomer and amalgam for the interproximal restoration of primary molars: a 24-month evaluation

OBJECTIVES

To evaluate the clinical performance of a compomer material (Dyract) in comparison with dental amalgam (Contour) for management of proximal caries in primary molars in young children.

SETTING

General dental practice, and a dental hospital paediatric clinic.

METHOD

This was a prospective study. A split mouth design was used with identical pairs of minimal Class II cavities, of matched tooth type in the same dental arch, usually diagnosed with the use of bitewing radiographs. Seventy-eight pairs of restorations were completed of which 60 pairs were available for evaluation after 24 months.

RESULTS

Comparable retention rates were observed for both Dyract and amalgam. The retention rates were high for both materials, with only four amalgam and two Dyract restorations failing over 24 months. Significantly better marginal integrity (P < 0.05) was observed for Dyract compared with amalgam with no significant differences between the two materials for recurrent caries, wear or surface texture.

CONCLUSIONS

Dyract seemed to be a suitable alternative to amalgam for proximal restorations in primary molars of young children for use in general dental practice.

Bedside ultrasound: a useful tool for the on-call urologist?

OBJECTIVE

To assess the accuracy and benefit of urgent bedside ultrasound scanning in urological emergencies by urology trainees.

METHODS

In this prospective study, 111 patients (86 acute flank pain, 15 renal failure, 10 haematuria) referred as urological emergencies, were scanned for urinary tract abnormalities at the bedside, by a trainee urologist, over 18 months. The ultrasound findings were compared with the results of imaging performed by a consultant radiologist and its influence on clinical management analysed.

RESULTS

Bedside ultrasound proved life saving in 5 patients (2 pyonephrosis, 2 leaking aneurysms, one bilateral ureteric injury). It significantly influenced management in 11 patients, excluded obstruction in the presence of infection.in 13 patients, helped in early diagnosis in 32 patients and ruled out gross urological pathology in 28 patients. It was misleading in 22 patients, mainly with ureteric colic (where the timing of the test can affect the findings), though the outcome was not adversely affected in any. Bedside ultrasound was reasonably accurate (sensitivity 81% and specificity 92%).

CONCLUSIONS

Bedside ultrasound is a useful tool to help the decision-making in urological emergencies and reasonably accurate in hands of a trainee urologist. It is especially helpful for excluding obstruction in presence of infection or renal failure. However it has inherent limitations in assessing acute ureteric colic.

Correlation between CT scan and automated perimetry in supratentorial tumors

An attempt was made to correlate various types of visual field defects on automated perimetry with the findings of computed tomography in 44 patients of supratentorial tumors. All the patients above the age of 10 years were subjected to complete neurological examination including investigations like plain X-rays and CT scan, however, MRI and angiography were performed wherever indicated. Ocular examination particularly pertaining to neuro-ophthalmological profile was carried out with special emphasis on automated perimetry on Humphrey field analyser. The results indicated that automated perimetry was capable of reliably detecting and quantitating the visual field defects and thus established the location of the tumor in 72% patients when compared to CT scan. Hence, any patient with neuro-ophthalmic features should be subjected to automated perimetry for early diagnosis and probable location of intracranial space occupying lesion affecting visual pathways.

Pseudoaneurysms of the femoral artery: recommendation for a method of repair

PURPOSE

Formation of an anastomotic aneurysm in the femoral artery is one of the major complications after femoral artery surgery. The aim of this study was to assess the method of repair of femoral anastomotic aneurysms and their outcome in a District General Hospital.

METHODS

A retrospective consecutive cohort of anastomotic femoral aneurysms, operated between 1977 and 1998, were studied.

RESULTS

Twelve patients with a total of 19 pseudoaneurysms were treated. Five of the aneurysms were repaired using a vein patch and two had re-suturing of the anastomosis. Twelve aneurysms were repaired with complete revision of the anastomoses using interposition grafts. There were no recurrences in the interposition graft group whilst two recurred in the seven aneurysms repaired using re-suturing/vein patch.

CONCLUSION

Interposition grafting would appear to be the method of choice for repair of femoral pseudoaneurysms as the outcome was better than that with re-suturing or using a patch closure technique.

Need for bringing in a change in biochemistry curriculum to make it clinically oriented?

OBJECTIVES

This study was conducted to (a) assess the views of medical students and doctors regarding relevance of biochemistry training, (b) explore if they have any suggestion to bring in any improvement in contents of biochemistry curriculum and mode of teaching.

METHODS

In 1997-98, a structured questionnaire was filled up by 114 medical students and 118 doctors.

RESULTS

As many as 62/114 (55%) medical students and 40/118 (34%) doctors believed that it is not important to remember minute details of biochemical reactions (p value < 0.0001). Among medical students, 108/110 (98.2%) agree that a clinician should be invited to seminars for developing skills of interpretation of laboratory investigations; whilst 110/118 (93.2%) doctors expressed similar view, p value ns. Approximately 92% responders favored that departments biochemistry and physiology should co-ordinate on the topics of common interest in order to save time and effort. What is the most informative and effective way of teaching biochemistry?' in response to this question only 0.9% responders opted lecture as the best option. Seminars with active participation of medical students was preferred by 93.2% responders. About 6.9% responders reckoned that symposium prepared by a more than one teacher. In response to the question whether it is possible to cover pre-clinical subjects in 12 months so as to allow spiral mode of curriculum, 73% of all the responders agreed that it would be good idea, there was no difference of opinion among the doctors and medical students. On the other hand, 27% were strongly opposed to this suggestion.

CONCLUSIONS

We suggest that there is a need to modify the contents, methods of teaching, and curriculum organization of training in clinical biochemistry. How best the curriculum can be made problem oriented needs to be debated among medical educationists.

Development of a single-reaction multiplex PCR toxin typing assay for Staphylococcus aureus strains

We describe here the development of a single-reaction multiplex PCR assay for the enterotoxin genes from Staphylococcus aureus that utilizes a universal toxin gene primer in combination with toxin-specific primers to amplify characteristic toxin gene products. In combination with a new DNA purification method, the assay can detect enterotoxin genes A to E from a pure culture within 3 to 4 h. The test was used to characterize a diverse set of environmental S. aureus isolates, and a 99% correlation with toxin typing using standard immunological tests was found. The design of the assay allows it to be extended to include both newly characterized and as-yet-unknown toxin genes.

Anti-invasive activity of alkaloids and polyphenolics in vitro

Invasiveness, the ability of certain tumour cells to migrate beyond their natural tissue boundaries, often leads to metastasis, and usually determines the fatal outcome of cancer. The need for anti-invasive agents has led us to search for possibly active compounds among alkaloids and polyphenolics. One hundred compounds were screened in an assay based on the confrontation of invasive human MCF-7/6 mammary carcinoma cells with fragments of normal embryonic chick heart in vitro. Anti-invasive activity was frequently found among chalcones having a prenyl group. Six compounds were found to inhibit invasion when added to the culture medium at concentrations as low as 1 microM. For at least three of them the anti-invasive effect could be associated with a cytotoxic effect on the MCF-7/6 cells, but not on the heart tissue. This selective cytotoxicity was substantiated by different methods, such as histology and growth assays (volume measurements, cell counts, MTT and sulforhodamine B assays). The anti-invasive effects of the compounds could neither be ascribed to induction of apoptosis nor to the promotion of cell-cell adhesion. Our data indicate that among the alkaloids and polyphenolics a number of molecules can inhibit growth and invasion of human mammary cancer cells via selective cytotoxicity.

Ductal (endometrioid) adenocarcinoma of the prostate: a clinicopathological study of 16 cases

Sixteen cases of ductal (endometrioid) carcinoma of the prostate are presented. The tumour presents in elderly men (age range 65-87 years) with haematuria or obstructive symptoms. Serum prostate specific antigen may be normal or raised. On cytoscopy, there is often an exophytic lesion in the region of the verumontanum. Histologically, two variants are recognized: papillary and cribriform, of which there were eight cases each. Eight cases consisted of pure ductal carcinoma and seven were mixed, containing a variable proportion of micro-acinar carcinoma. The associated micro-acinar carcinoma had a Gleason score of at least 5. One case of carcinosarcoma with a ductal epithelial component was also included. All cases displayed positive immunohistochemical staining for prostate specific antigen and prostatic acid phosphatase and but were negative for the basal cell marker MA903. The tumour responds well to orthodox micro-acinar carcinoma therapy and appears notably sensitive to hormonal manipulation. Follow-up of the mixed group is restricted to a maximum of 3 years. Of the eight pure cases, five patients are still alive with survival periods of 11, 8, 7, 3 and 1 years. Three patients died of intercurrent disease of which one patient survived 12 years, having received no treatment. This tumour, therefore, can be regarded as having a good prognosis.

A study of immunoglobulins and complements (C3 & C4) in alopecia areata

Estimation of serum Immunoglobulins (IgG, IgM and IgA) and complements (C3 and C4) was carried out in 100 cases of alopecia areata as per method described by Mancini (1965).[1] Clinically patients were divided in two groups, alopecia areata circumscribed (group I) and severe alopecia areata (group II). Significant decrease in levels of one or more Immunoglobulins were observed in most of the patients. However, Serum complements (C3 and C4) were within range of normal control values.

Heterogeneity in chemical mutagen-induced chromosome damage after G2 phase exposure to bleomycin, ara-C and gentian violet in cultured lymphocytes of beta-thalassaemia traits

Chemical mutagen-induced chromosome damage was analysed in cultured peripheral blood lymphocytes from beta-thalassaemia traits and healthy individuals. This was promoted by the fact that beta-thalassaemia trait is present in 1-17% of different population groups in India. To study mutagen-induced chromosome instability, G2 lymphocytes were exposed to bleomycin, ara-C or gentian violet in 48-h cultures. Spontaneous chromosome aberration frequencies in lymphocytes from beta-thalassaemia traits were found to be in the normal range. In all three clastogen-treated lymphocytes from beta-thalassaemia traits, there is a degree of hypersensitivity, when the results are averaged over a number of individuals, but some individuals overlap within the normal range. The heterogeneity in chemical mutagen sensitivity observed in beta-thalassaemia traits is discussed in terms of the oxidative damage consequent on the genetic and biochemical features peculiar to the beta-thalassaemia trait cell.

Angiokeratoma corporis diffusum

A case of angiokeratoma corporis diffusum having some classical features with dilatation of retinal vessels, but without urinary signs of renal involvement, is reported.

A study of peripheral T-Lymphocytes in alopecia areata

Estimation of peripheral T-lymphocytes (active and total) was carried out in 100 cases of alopecia areata as per method described by Boyam (1977) and West et al (1978). Clinically patients were divided in two groups, alopecia areata circumscribed (group I) and severe alopecia areata (group II). Thirty healthy subjects served as controls. Decrease in percentage of both active and total E-RFC was observed in 70% cases. The decrease was more significant in group II.

Acneform eruptions and antitubercular drugs

Out of total 774 cases under antitubercular therapy only 11 cases (1.42%) developed acneform eruptions. Individual drugs found to cause these eruptions were Isoniazid (0.53%), Rifampicin (1.48%) and Ethambutol (0.63%).