Issue 3-The occupational burden of respiratory diseases, an update.

INTRODUCTION AND AIMS: Workplace exposures are widely known to cause specific occupational diseases such as silicosis and asbestosis, but they also can contribute substantially to causation of common respiratory diseases. In 2019, the American Thoracic Society (ATS) and the European Respiratory Society (ERS) published a joint statement on the occupational burden of respiratory diseases. Our aim on this narrative review is to summarise the most recent evidence published after the ATS/ERS statement as well as to provide information on traditional occupational lung diseases that can be useful for clinicians and researchers. RESULTS: Newer publications confirm the findings of the ATS/ERS statement on the role of workplace exposure in contributing to the aetiology of the respiratory diseases considered in this review (asthma, COPD, chronic bronchitis, idiopathic pulmonary fibrosis, hypersensitivity pneumonitis, infectious pneumonia). Except for COPD, chronic bronchitis and infectious pneumonia, the number of publications in the last 5 years for the other diseases is limited. For traditional occupational lung diseases such as silicosis and asbestosis, there are old as well as novel sources of exposure and their burden continues to be relevant, especially in developing countries. CONCLUSIONS: Occupational exposure remains an important risk factor for airways and interstitial lung diseases, causing occupational lung diseases and contributing substantially in the aetiology of common respiratory diseases. This information is critical for public health professionals formulating effective preventive strategies but also for clinicians in patient care. Effective action requires shared knowledge among clinicians, researchers, public health professionals, and policy makers.

T11TS immunotherapy potentiates the repressed calcineurin-NFAT signalling pathway of T cells in Cryptococcus neoformans infected rats: a cue towards T-cell activation for antifungal immunity.

AIMS: To examine the modulation of the interacting partners of the calcineurin (CaN)-NFAT pathway in T cells during Cryptococcus neoformans fungal infection and post-T11TS immunotherapy. METHODS AND RESULTS: Wistar rats were infected with C. neoformans and followed by immunotherapy with immune-potentiator T11TS. T cells were analysed by flow cytometry, immunoblotting and nuclear translocation study. The signalling proteins LCK, FYN, LAT, PLCγ1 and CaN in T cells were regulated by C. neoformans infection resulting in reduced nuclear translocation of NFAT and IL-2 expression. Following T11TS immunotherapy, the expressions of the above-mentioned proteins were boosted and thus resulting in the clearance of C. neoformans from lung and spleen. CONCLUSIONS: The precise mechanism of suppression of the T-cell function by C. neoformans is still unknown. Previously, we have shown that T11TS positively regulates the function of T cells to abrogate glioma and other immunosuppressive conditions. T11TS immunotherapy increased the expression of the above signalling partners of the CaN-NFAT pathway in T cells and improved nuclear retention of NFAT. As a result, an increased IL-2 expression leads to activation and proliferation of T cells. SIGNIFICANCE AND IMPACT OF THE STUDY: Our results demonstrate the role of T11TS in restoring the CaN-NFAT signalling pathway in T cells. It identifies T11TS as an immunotherapeutic agent with potential clinical outcomes to counteract C. neoformans infection.

Respiratory Morbidity among Indian Tea Industry Workers.

BACKGROUND: Indian tea industry workers are exposed to various exposures at their workplace. OBJECTIVE: To investigate the respiratory health of Indian tea industry workers. METHODS: We administered a respiratory questionnaire to and measured lung function in workers of 34 tea gardens and 46 tea factories. We used correlation matrices to test the association between their respiratory symptoms and lung functions. RESULTS: The garden workers complained of shortness of breath 3 times higher than the factory workers. However, nasal allergy was more predominant among the factory workers compared to garden workers (69.6% vs 41.2%, p=0.02). The factory workers had higher total (median 107.3% vs 92.9%, p=0.05, as measured by R at 5 Hz) and peripheral airway resistance (143.8% vs 61.1%, p=0.005, as measured by R at 5-20 Hz) than the garden workers. Respiratory symptoms were inversely associated with airway obstruction as measured by the ratio between forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) and positively correlated with increased overall airway reactance among the workers. CONCLUSION: Respiratory symptoms and increased allergen susceptibility of Indian tea industry workers due to occupational exposures warrant routine systematic surveillance of their workplace air quality and health monitoring.

Airflow obstruction among street vendors who refill cigarette lighters with liquefied petroleum gas.

BACKGROUND: Manual cigarette lighter refilling with butane/propane admixed liquefied petroleum gas (LPG) is a common low-income occupation in India. This practice may cause adverse health effects from LPG exposure among such workers. OBJECTIVE: To assess respiratory status among LPG-exposed workers and non-exposed controls. METHODS: We quantified the exposure and evaluated respiratory symptoms and lung function among 113 LPG refilling workers (aged 41.9±9.9 years) and 79 controls (aged 40.8±7.2 years). We used multiple linear regression analysis to estimate the LPG exposure response within the group of refilling workers, adjusting for age, height and smoking status. RESULTS: Compared to the controls, the LPG-exposed lighter refillers manifested a 190 ml decrement in 1-second forced expiratory volume (FEV1) (2.55±0.4 vs. 2.26±0.3 l) and a 6% decrement in FEV1/forced vital capacity (FVC) (both P < 0.05). We found a significantly negative exposure response among the LPG workers: for FVC and FEV1, 44 ml per ml of reported daily LPG use in refilling (P < 0.05). CONCLUSION: Likely heavy exposure to LPG through manually refilling cigarette lighters is associated with airflow decrements. This adverse effect may be relevant to other occupational groups heavily exposed to volatile hydrocarbons, especially those in marginal employment sectors.

Diagnostic dilemma of dengue fever: how much reliability are there in rapidity.

Rapid diagnosis of dengue infection is essential to patient management and disease control. In a rural tertiary health setting and diagnostic laboratories, dengue suspect cases were assessed with a rapid (15 minutes) immunochromatographic test and compared to an IgM capture enzyme-linked immunosorbent assay (ELISA) (2-3 days) and the reliability of the rapid test was tested. The objectives were to evaluate dengue rapid test against dengue IgM capture ELISA and to assess the scopes of such rapid tests in peripheral setting. A rapid immunochromatographic card test was compared with an IgM capture ELISA (National Institute of Virology, Pune, India) as the reference gold standard. The sensitivity and specificity of the test was compared over a period of five years in a rural tertiary hospital among 158 dengue suspects. The rapid test showed good sensitivity in the diagnosis of both primary and secondary dengue infection. The rapid test as confirmed by IgM capture ELISA was found to have specificity of 98.4% and a sensitivity of 96.4%.The positive predictive value was 93.1% and negative predictive value of 99.2%.The positive likelihood ratio worked out to be 62.6,with negative likelihood ratio was 0.036,signifying large impact. The rapid tests may be useful aid in screening in case of clinical diagnosis of dengue infection,particularly valuable in peripheral health settings,where it can hasten the initiation of firstline of management; while the ELISA has a place in central testing laboratories, aiding in resource optimisation.

Skin and soft tissue infections: development of a collaborative management plan between community and hospital care.

The commonest indication in the US for referral to an outpatient/home i.v. antibiotic therapy programme is the management of skin and soft tissue infections. In the UK, however, these infections account for 10% or more of admissions to infection units. The main indication for hospitalisation is to receive parenteral antibiotics. A retrospective audit of one year of admissions to a regional infection unit revealed that, although most of these patients do not progress to complications ('low risk'), they occupy a mean time of five days in hospital and for nearly half of that time they receive parenteral antibiotics. This period in hospital reflected 11.4% of the unit's bed occupancy. Even if 75% of these patients were treated in the community with parenteral therapy, this would result in bed savings of 8.55%, nearly one-tenth of the unit's occupied capacity. This type of audit should help key decision makers thinking of developing similar services in their region. Outpatient or home parenteral antimicrobial therapy (OHPAT) should be delivered as part of a complete disease management programme in collaboration with primary care.

Biochemical analysis of the stress protein response in human oesophageal epithelium.

BACKGROUND: The oesophageal epithelium is exposed routinely to noxious agents in the environment, including gastric acid, thermal stress, and chemical toxins. These epithelial cells have presumably evolved effective protective mechanisms to withstand tissue damage and repair injured cells. Heat shock protein or stress protein responses play a central role in protecting distinct cell types from different types of injury. AIM: To determine (i) whether biochemical analysis of stress protein responses in pinch biopsy specimens from human oesophageal epithelium is feasible; (ii) whether undue stresses are imposed on cells by the act of sample collection, thus precluding analysis of stress responses; and (iii) if amenable to experimentation, the type of heat shock protein (Hsp) response that operates in the human oesophageal epithelium. METHODS: Tissue from the human oesophagus comprised predominantly of squamous epithelium was acquired within two hours of biopsy and subjected to an in vitro heat shock. Soluble tissue cell lysates derived from untreated or heat shocked samples were examined using denaturing polyacrylamide gel electrophoresis for changes in: (i) the pattern of general protein synthesis by labelling epithelial cells with 35S-methionine and (ii) the levels of soluble Hsp70 protein and related isoforms using immunochemical protein blots. RESULTS: A single pinch biopsy specimen is sufficient to extract and analyse specific sets of polypeptides in the oesophageal epithelium. After ex vivo heat shock, a classic inhibition of general protein synthesis is observed and correlates with the increased synthesis of two major proteins of molecular weight of 60 and 70 kDa. Notably, cells from unheated controls exhibit a "stressed" biochemical state 22 hours after incubation at 37 degrees C, as shown by inhibition of general protein synthesis and increased synthesis of the 70 kDa protein. These data indicate that only freshly acquired specimens are suitable for studying stress responses ex vivo. No evidence was found that the two heat induced polypeptides are previously identified Hsp70 isoforms. In fact, heat shock results in a reduction in the steady state concentrations of Hsp70 protein in the oesophageal epithelium. CONCLUSION: Systematic and highly controlled studies on protein biochemistry are possible on epithelial biopsy specimens from the human oesophagus. These technical innovations have permitted the discovery of a novel heat shock response operating in the oesophageal epithelium. Notably, two polypeptides were synthesised after heat shock that seem to differ from Hsp70 protein. In addition, the striking reduction in steady state concentrations of Hsp70 protein after heat shock suggests that oesophageal epithelium has evolved an atypical biochemical response to thermal stress.

On the morpho-histology of the alimentary tract in the Indian climbing perch, Anabas testudineus (Bloch), in relation to food and feeding habits.

Functional morpho-histology of the alimentary tract of the Indian Climbing perch, Anabas testudineus (BLOCH) has been described. The fish possesses a wide, slightly upturned mouth. The presence of jaw, vomerine, palatine, pharyngeal, and horny pad teeth in the bucco-pharyngeal region indicates the carnivorous feeding habit of the fish. Gill-rakers are toothed but the tongue is edentulous. The latter helps in manipulation of larger prey. The nature and disposition of the taste buds in the lips and bucco-pharyngeal region indicate that the fish procures its food primarily by taste and secondarily by sight. Taste buds are also present in the middle oesophagus which indicates that the gustatory sense extends upto this region. The surface epithelium of the cardiac stomach is conspicuous in having specific mucous cells. The pyloric stomach indicates a more primitive nature due to the presence of tubular mucous glands or pyloric glands. The number of pyloric caeca is 4. The intestine is slightly looped and the dimensionless RLG (Relative Length of the Gut) is 0.42. An ileo-rectal valve and the mucosal folds distinguish the rectum from the intestine.

Morpho-histology of the hypothalamo-neurohypophyseal system in relation to gonadal maturation in Cirrhinus mrigala (Ham.), a freshwater Indian carp.

The hypothalamic neurosecretory centres, their pathway and the role of neurosecretory material responsible for gonadal maturation during its annual cycle is being reported here for the first time in an Indian freshwater major carp, Cirrhinus mrigala (Ham.).

Morpho-histology of the alimentary canal of an Indian fresh-water perch, Colisa fasciata (Bloch) in relation to food and feeding habits.

The morpho-histology of the alimentary canal in an Indian freshwater perch, Colisa fasciata (Bloch) in relation to food and feeding habits has been described. C. fasciata is an omnivorous, mid-feeder. The mouth is protractile. The alimentary canal comprises the lip, buccal cavity, pharynx, oesophagus, stomach, pyloric caeca, a long and coiled intestine and the rectum. The teeth on the roof and floor of the buccal cavity, jaw teeth, pharyngeal teeth and horny pad teeth are all adapted to the nature of the food ingested. The nature and disposition of taste-buds and mucous cells on the lips suggests that the fish is a taste-feeder. The presence of taste-buds in the anterior oesophagus indicates that the gustatory sense extends upto the oesophagus. The stomach is divided into the cardiac and pyloric regions. The surface epithelium of the cardiac stomach secretes mucous and the glandular epithelium contains numerous gastric glands. The pyloric caeca are paired. The intestine is divided into anterior, middle and posterior regions. The R.L.G. (relative length of the gut) varies from 4--5. Mucosal folds are simple.

Seasonal variations in the histology of the pituitary gland of Cirrhinus mrigala (Ham.) an Indian freshwater major carp, in relation to gonadal activity.

1. Seasonal variations in the histology of the pituitary gland of Cirrhinus mrigala (Ham.), an Indian freshwater major carp, in relation to gonadal activity has been studied during a one year period commencing, January, 1971. 2. The proximal pars distalis undergoes a great deal of seasonal variation in size, weight and nature of pituicytes. 3. The percentage composition of acidophils and cyanophils in the proximal pars distalis show a reciprocal relationship during the year. The acidophils predominate during the restitution phase of the gonads while the cyanophils preponderate among the different cell types during the breeding season. 4. The chromophobes do not show any significant fluctuation in numerical abundance in relation to gonadal activity. 5. Cyanophils of the proximal pars distalis undergo changes with change in gonadal activity Concentration of glycoproteinaceous material is extremely low during the restitution phase but high during the maturation phase. The cyanophils also undergo hypertrophy and hyperplasia during the spawning period. The latter discharge their contents and become vacuolated during the post spawning period. 6. The number and size of the globules in the cyanophils are related to gonadal activity. 7. Acidophils present in the rostral pars distalis and pars intermedia do not appear to be related to gonadal activity in C. mrigala. 8. The average weight of the gland is directly related to the state of maturation of the gonads, an observation being recorded here for the first time.