Biomedical subjects

A Mitra

Publications and source records attributed to A Mitra.

At least 37 records · Page 2Linked to original sources

PubMed2004

A generalized scale of free energy of excess adsorption of solute and absolute composition of the interfacial phase.

Moles of a surfactant (gamma2(1)) absorbed per unit area of the solid-liquid interface estimated analytically from the difference of the solute molality in the bulk phase before and after adsorption have been quantitatively related to the absolute compositions deltan1 and deltan2 of the solvent and solute forming the inhomogeneous surface phase in contact with the bulk phase of homogeneous composition. By use of isopiestic experiments, negative values of gamma2(1) for the adsorption of inorganic salts onto a solid-liquid interface have been calculated in the same manner. From the linear plot of gamma2(1) versus the ratio of the bulk mole fractions of the solute and solvent, values of deltan1 and deltan2 have been evaluated under a limited range of concentrations. For the adsorption of the surfactant and the inorganic salt respectively onto the fluid interface, gamma2(1) values have been evaluated from the surface tension concentration data using the Gibbs adsorption equation. Gamma2(1) based on the arbitrary placement of the Gibbs dividing plane near the fluid interface is quantitatively related to the composition of the inhomogeneous surface phase. Also, the Gibbs equation for multicomponent solutions has been appropriately expressed in terms of a suitably derived coefficient m. Integrating the Gibbs adsorption equation for a multicomponent system, the standard free energy change, deltaG degrees, per unit of surface area as a result of the maximum adsorption gamma2(m) of the surfactant at fluid interfaces due to the change of the activity alpha2 of the surfactant in the bulk from zero to unity have been calculated. A similar procedure has been followed for the calculation of deltaG degrees for the surfactant adsorption at solid-liquid interfaces using thermodynamically derived equations. deltaG degrees values for surfactant adsorption for all such systems are found to be negative. General expressions of deltaG degrees for negative adsorption of the salt on fluid and solid-liquid interfaces respectively have also been derived on thermodynamic grounds. deltaG degrees for all such systems are positive due to the excess spontaneous hydration of the interfacial phase in the presence of inorganic salt. Negative and positive values of deltaG degree for excess surfactant and salt adsorption respectively have been discussed in light of a generalized scale of free energy of adsorption.

Journal Article↗

PubMed2004

Ketotifen alone or as additional medication for long-term control of asthma and wheeze in children.

BACKGROUND: Ketotifen is an antihistamine which may be used to treat asthma. Since administering inhaled therapy to younger children can be difficult, an oral agent such as ketotifen offers potential advantages. OBJECTIVES: The objective of this review is to determine, whether ketotifen alone or in combination with other co-interventions results in better control of asthma in children with asthma and/or wheezing and examine its safety profile. SEARCH STRATEGY: We searched the Cochrane Airways Group register of trials (based on MEDLINE, EMBASE, CINAHL and handsearched respiratory journals) and reference lists of articles. The latest search was carried out in October 2002. SELECTION CRITERIA: Clinical studies had to be randomised-controlled and double-blinded, comparing oral ketotifen with placebo in children with asthma and/or wheeze for at least eight weeks at a dose not less than one mg daily. DATA COLLECTION AND ANALYSIS: Two reviewers independently performed selection of trials, quality assessment and data extraction; a third reviewer was included in the consensus process if necessary. MAIN RESULTS: A total of 26 relevant studies involving 1826 participants were included in this review. Children's age ranged from 4 months to 18 years and ketotifen was given between 10 and 32 weeks. The proportion of children able to reduce or stop their bronchodilator use within 12 to 16 weeks of treatment was significantly higher in the ketotifen group (relative risk 2.39, 95% CI 1.64 to 3.48) based on four trials; this result was statistically significant in a subgroup of two trials with well described and adequate method of blinding. Statistically significant beneficial effects of ketotifen were also observed in the following secondary outcomes: efficacy evaluated by physician (10 trials) and parents/patients (7 trials), asthma symptom score (4 trials), asthma exacerbations (2 trials), and reduction in use of oral steroids (4 trials). However, sub-group analyses of trials with well described and adequate method of blinding was only significant for the outcome asthma symptom score and non-significant for the remaining secondary outcomes. Reported side effects were more frequent in the ketotifen group (sedation: 21%, weight gain: 27%) than in the placebo group (sedation: 12%, weight gain: 17%). REVIEWER'S CONCLUSIONS: Evidence from randomised controlled trials indicates that ketotifen alone or in combination with other co-interventions improves control of asthma and wheezing in children with mild and moderate asthma. However due to the high proportion of children with atopy in some trials the results cannot necessarily be generalised to all asthmatic children. The benefit is obtained at the cost of minor side effects, namely sedation and weight gain. The validity of this conclusion is limited by the low reported, methodological quality of included trials.

Anti-Asthmatic Agents↗

PubMed2003

The current role of intravenous aminophylline in acute paediatric asthma.

Intravenous aminophylline is effective in children with acute asthma and was the bronchodilator of choice for many years. However, with the advent of inhaled b agonists and anticholinergic agents an alternative, less invasive, therapeutic strategy is currently available. If children with acute asthma fail to respond to inhaled therapy clinicians may consider aminophylline a controversial treatment. The published evidence on whether aminophylline produces further beneficial effect in children already receiving inhaled therapy for acute asthma is reviewed in this paper. The published randomised controlled trials comparing aminophylline with placebo are of good methodological quality, although the numbers of children in many of the studies are small. Trial outcomes included lung function (FEV1 and PEF) and clinical scoring of asthma severity. Aminophylline improved percentage predicted FEV1 by 6 hours, and this effect was maintained for 24 hours. Improvements were also seen in clinical asthma severity scores at 6 hours. Despite improvements in lung function and asthma severity, there was no reduction in hospital stay or the number of nebulisers required. The main side effect of aminophylline therapy was an increased incidence of vomiting. In conclusion, the addition of intravenous aminophylline should be considered early in the treatment of children hospitalised with acute severe asthma with suboptimal response to the initial inhaled bronchodilator therapy. Further research should be carried out to examine whether intravenous aminophylline may have a beneficial effect in other settings such as intensive care to determine if it may reduce intubation and ventilation rates.

Acute Disease↗

PubMed2002

Clinical and immunological assessment of Mycobacterium vaccae (SRL172) with chemotherapy in patients with malignant mesothelioma.

The objectives of this study were to determine the toxicity of intratumoural/intrapleural SRL172 in addition to intradermal SRL172 and standard chemotherapy (mitomycin-C, vinblastine and cisplatin) in patients with malignant mesothelioma. Patients received chemotherapy (mitomycin-C: 8 mg m(-2), vinblastine: 6 mg m(-2), cisplatin 50 mg m(-2)) on a 3-weekly basis for up to six courses. IP SRL172 injections were given 3-weekly prior to chemotherapy and escalated in groups of three patients from 1 microg to 1 mg bacilli in 10-fold increments. Patients were also given ID SRL172 at a dose of 1 mg bacilli 4-weekly. Patients were assessed for toxicity after each course of chemotherapy and for response by CT imaging. Immuno-haematological parameters were analyzed pre-treatment and 1 month after completion of treatment. There was no dose limiting toxicity with IP SRL172 although there was greater toxicity at the highest dose (n=13). There were six out of 16 partial responses (37.5%). Haemato-immunological parameters, measured in seven patients pre and post-therapy, revealed that response rate correlated with a decrease in platelet count and there was an increase in activation of natural killer cells and a decrease in the percentage of IL-4 producing T cells in all tested patients post-treatment. SRL172 can be given safely into tumour deposits and the pleural cavity in patients with malignant mesothelioma and we have established the dose for phase II testing.

Aged↗

PubMed2002

Evaluation of chemical constituents and free-radical scavenging activity of Swarnabhasma (gold ash), an ayurvedic drug.

From ancient times, Swarnabhasma (gold ash) has been used in several clinical manifestations including loss of memory, defective eyesight, infertility, overall body weakness and incidence of early aging. Swarnabhasma has been used by Ayurvedic physicians to treat different diseases like bronchial asthma, rheumatoid arthritis, diabetes mellitus, nervous disorders, etc. In the present investigation, Swarnabhasma was prepared after proper purification and calcination as per Ayurvedic pharmacy which consisted of Realger (As(2)S(2)), Lead oxide (Pb(3)O(4)), Pure gold (Au) and Latex of Calotropis gigantea. Qualitative analyses indicated that Swarnabhasma contained not only gold but also several microelements (Fe, Al, Cu, Zn, Co, Mg, Ca, As, Pb, etc.). Infrared spectroscopy showed that the material was free from any organic compound. The metal content in the bhasma was determined by atomic absorption spectrometry. Acute oral administration of Swarnabhasma showed no mortality in mice (up to 1 ml /20 g b.w. of Swarnabhasma suspension containing 1mg of drug). Chronic administration of Swarnabhasma also showed no toxicity as judged by SGPT, SGOT, serum creatinine and serum urea level and histological studies. In an experimental animal model, chronic Swarnabhasma-treated animals showed significantly increased superoxide dismutase and catalase activity, two enzymes that reduce free radical concentrations in the body.

Animals↗

PubMed2002

Purification of pulp and paper mill effluent using Eichornia crassipes.

Konark Pulp and Paper Industries Private Limited is a medium size industry producing 1600 m3 of wastewater a day. The existing water treatment system of the industry was found to be ineffective both in performance and economy. In the present study, a new system of treatment has been developed using water hyacinth Eichornia crassipes, coagulation by lime and alum, followed by rapid sand filtration. The performance efficiency of each unit viz. Eichornia treatment; coagulation with lime, with alum, and with lime:alum combinations, and filtration was studied. Water quality parameters considered were Biological Oxygen Demand, Chemical Oxygen Demand, Dissolve Oxygen, Total Dissolved Solids, turbidity, percentage transmission, and water colour. Based on the individual performance of each unit, a continuous system has been designed and was tested. The new system of treatment could treat the wastewater to the discharge standards and also was found economically feasible. Testing culture of fish (tilapia) proved that the treated water could be safely discharged into natural waters. All fish tested, survived and remained healthy throughout the period of testing. Culture of fish further improved the water quality.

Alum Compounds↗

PubMed2001

Delay of intracellular calcium transients using a calcium chelator: application to high-throughput screening of the capsaicin receptor ion channel and G-protein-coupled receptors.

Whole-cell functional assays are often used for high-throughput screening (HTS) of molecular targets such as ion channels and G-protein-coupled receptors. A common method for assaying the activity of these membrane proteins is to measure the change in intracellular calcium concentration upon receptor stimulation. These changes in calcium concentration are typically transient and therefore not readily adapted to high-density plate formats used in HTS instruments. We have demonstrated that an intracellular calcium chelator, BAPTA, was able to delay by 5- to 20-fold and extend for several minutes the observed calcium signals initiated by extracellular calcium influx or release of calcium from intracellular stores. As examples, we used cells expressing a calcium-permeable ion channel, vanilloid receptor type 1 (the capsaicin receptor), and two G-protein-coupled receptors. These receptor-mediated increases in intracellular calcium concentration were measured by both fluorescence-based and luminescence-based detection methods. The use of an intracellular calcium chelator to delay calcium signaling should have wide application since it allows the measurement of the functional activity of any cellular receptor that signals through calcium. With this procedure, calcium fluorescence and luminescence whole-cell functional assays may be performed with standard laboratory pipetting and detection systems.

Calcium↗

PubMed2001

Intravenous aminophylline for acute severe asthma in children over 2 years using inhaled bronchodilators.

BACKGROUND: Intravenous aminophylline was the bronchodilator of choice for many years until supplanted by more effective bronchodilators in the treatment of acute paediatric asthma. Recently there has been renewed interest in this therapy for children with acute severe asthma. OBJECTIVES: To determine whether addition of intravenous aminophylline produces a beneficial effect in children with acute severe asthma receiving oxygen, maximised inhaled bronchodilators and oral/intravenous glucocorticoids. SEARCH STRATEGY: The Cochrane Airways Group register of trials (based on MEDLINE, EMBASE, CINAHL and hand searched respiratory journals) and reference lists of relevant articles were used to identify relevant studies. The latest search was carried out in October 2000. SELECTION CRITERIA: Only randomised-controlled trials comparing intravenous aminophylline with placebo in children treated with inhaled bronchodilators and systemic glucocorticoids for acute asthma were considered for this review. DATA COLLECTION AND ANALYSIS: Full text of 35 trials were anonymized for author, date and publication and two blinded independent reviewers selected eligible studies for inclusion. Disagreement was resolved through consensus. Seven trials met the inclusion criteria. Attempts were made to contact authors to verify accuracy. Results were reported as weighted mean differences (WMD) or relative risk (RR) with 95% confidential intervals (CI). MAIN RESULTS: Patients in these trials were predominantly school-aged children hospitalised for acute severe asthma with a baseline FEV1 at 35-40% of predicted and/or a baseline Pulmonary Index of 6-7. Aminophylline significantly improved percentage predicted FEV1 by 6 - 8 hours (WMD 8.4%; 95% CI: 0.82, 15.92%). The effect was maintained for 24 hours. Improvements were also seen in symptom scores at 6-8 hours (WMD= -0.71; 95% CI: -0.82,-0.60). There was no reduction in hospital stay or in number of nebulisers required. Vomiting was more likely with aminophylline therapy (Relative Risk = 3.69; 95% CI: 2.15, 6.33). REVIEWER'S CONCLUSIONS: Addition of intravenous aminophylline should be considered early in the treatment of children hospitalised with acute severe asthma with sub optimal response to the initial inhaled bronchodilator therapy. Although the improvement is sustained for 24 hours, there is no apparent reduction in length of hospital stay or number of inhaled beta2-agonists nebulisations. Treatment with aminophylline is associated with an increased risk of vomiting.

Acute Disease↗

PubMed2001

Human cervical tumor cell (SiHa) surface alphavbeta3 integrin receptor has associated matrix metalloproteinase (MMP-2) activity.

PURPOSE: Integrins are transmembrane heterodimeric molecules that mediate cellular adhesion and are involved in different biological processes, such as tumor development and invasion of tumor cells. Matrixmetalloproteases (MMP) are a family of secreted or membrane proteins capable of digesting extracellular matrix. It has been shown that MMP-2 binds to alphavbeta3 integrin. Recent evidence suggests that a complex of membrane-type MMP (MT1-MMP) and tissue inhibitor of metalloptroteinase-2 (TIMP-2) participate in the activation of alphavbeta3-associated MMP-2. We investigated whether alphavbeta3 and MMP-2 are associated on the membranes of a human cell line, SiHa, and the possible involvement of MT1-MMP and TIMP-2 in the modulation of MMP-2 activity. METHODS: Immunoprecipitation of SiHa membrane extracts with monoclonal antibodies against alphav or MMP-2, and western blots of immunoprecipitates and serum-free conditioned media were performed. TIMP-2 in conditioned medium and MT1-MMP in the membrane fraction was assayed by western blot. Zymography of anti-alphav antibody immunoprecipitates and conditioned media were used to show gelatinolytic activity. RESULTS: The coprecipitation of MMP-2 with alphavbeta3 by anti-alphav antibody is a strong indication that SiHa cell surface alphavbeta3 integrin is a receptor for MMP-2. Immunoblot assays show the expression of MT1-MMP on SiHa cell membranes and secreted TIMP-2 and pro-MMP-2 in the medium. CONCLUSIONS: SiHa cells express all the molecules which are reported to form a complex to activate pro-MMP-2. Active MMP-2 associated with alphavbeta3 may regulate matrix degradation and thereby modulate directed motility of SiHa cells.

Biotinylation↗

PubMed2001

Accumulation of barley stripe mosaic virus is significantly reduced in transgenic wheat plants expressing a bacterial ribonuclease.

An rnc70 gene encoding a mutant bacterial ribonuclease III (RNase III) was introduced into wheat (Triticum aestivum cv. Bobwhite) by microprojectile bombardment. T1, T2, and T3 plants regenerated from three transgenic callus lines were challenged with barley stripe mosaic virus. Plants expressing RNase III exhibited a high level of resistance to the virus infection. This resistance was evidenced by the absence of virus symptoms and reduced accumulation of virions in these plants. The result demonstrates that this pathogen-targeted resistance strategy can be effectively employed in conferring resistance to viral diseases of cereal crops.

Blotting, Western↗

PubMed2001

Hereditary distal renal tubular acidosis: new understandings.

The primary or hereditary form of distal renal tubular acidosis (dRTA), although rare, has received increased attention recently because of dramatic advances in the understanding of its genetic basis. The final regulation of renal acid excretion is effected by various acid/base transporters localized in specialized cells in the cortical collecting and outer medullary collecting tubules. Inherited defects in two of the key acid/base transporters involved in distal acidification, as well as mutations in the cytosolic carbonic anhydrase gene, can cause dRTA. The syndrome is inherited in both autosomal dominant and recessive patterns; patients with recessive dRTA present with either acute illness or growth failure at a young age, sometimes accompanied by deafness, whereas dominant dRTA is usually a milder disease and involves no hearing loss. The AE1 gene encodes two Cl-/HCO3- exchangers that are expressed in the erythrocyte and in the acid-secreting intercalated cells of the kidney. AE1 contributes to urinary acidification by providing the major exit route for HCO3- across the basolateral membrane. Several mutations in the AE1 gene cosegregate with dominant dRTA. The modest degree of hypofunction exhibited in vitro by these mutations, however, does not explain the abnormal distal acidification phenotype. Other AE1 mutations have been linked to a recessive syndrome of dRTA and hemolytic anemia in which hypofunction can be discerned by in vitro studies. Several mutations in the carbonic anyhdrase II gene are associated with the autosomal recessive syndrome of osteopetrosis, renal tubular acidosis, and cerebral calcification. Some of these individuals present with deafness of the conductive type. By contrast, more recent studies have shown that mutations in ATP6B1, encoding the B-subtype unit of the apical H(+) ATPase, are responsible for a group of patients with autosomal recessive dRTA associated with sensorineural deafness. Thus, the presence of deafness and the type provide an important clue to the genetic lesion underlying hereditary dRTA.

Acidosis, Renal Tubular↗

PubMed2001

Early retardation of 99mTc-DTPA radioaerosol transalveolar clearance in irradiated canine lung.

UNLABELLED: The alteration of 99mTc-labeled diethylenetriaminepentaacetic acid (DTPA) transalveolar clearance in an initial phase of radiation lung injury was experimentally investigated. METHODS: Fourteen dogs were irradiated to the hemithorax with a single dose of 20 Gy. A DTPA radioaerosol study was performed before irradiation and on day 12 after irradiation. On day 14, the DTPA study was repeated again, with seven animals undergoing the study after inhalation of an aerosolized synthetic surfactant. The penetration index (P.I.) and clearance half-time (T(1/2)) of DTPA were measured in each lung. To evaluate the changes in lung surfactant after irradiation, alveolar lipids were stained in the resected lungs (n = 14), and the amounts of alveolar surfactant phospholipid and protein were measured by a bronchoalveolar lavage study in another six irradiated dogs. RESULTS: In all of the 14 irradiated animals, DTPA radioaerosol distributed uniformly throughout the lungs without significant changes in P.I. The T(1/2) values in irradiated lungs were significantly prolonged compared with the matched baseline values and those in nonirradiated lungs (P < 0.05 and 0.001, respectively). The aerosolized synthetic surfactant retarded the DTPA clearance both in the irradiated and in the nonirradiated lungs (P < 0.001) without significant changes in P.I. The histologic and bronchoalveolar lavage studies revealed an increase of alveolar surfactant materials in the irradiated lungs without substantial histologic changes in the alveolar structures. CONCLUSION: DTPA transalveolar clearance was retarded soon after irradiation. Increased alveolar surfactant may be partly responsible for this retarded DTPA clearance because the aerosolized synthetic surfactant also prolonged the clearance in nonirradiated lungs. A DTPA clearance test is sensitive for the early detection of radiation lung injury and seems helpful for clarifying the association of epithelial integrity changes and lung surfactant in radiation lung injury.

Administration, Inhalation↗

PubMed2001

Role of alphavbeta3 integrin receptors in breast tumor.

The intriguing problem of tumor metastasis involves adhesion of the metastatic cells via the integrin group of cell surface receptors to the ECM proteins of the basement membrane. Modulation of integrin family of cell surface receptors is believed to be associated with stages of tumor metastasis. In this present study, results obtained indicate that alphavbeta3 vitronectin receptors may play an important role in the malignant behaviour of human breast tumor. Alphavbeta3 integrin receptors can modulate the activity of collagenase enzyme and thereby the invasive property of breast tumor cells.

Breast Neoplasms↗

PubMed2001

Binding of globular proteins to DNA from surface tension measurement.

Extent of binding (gammap) of globular proteins to calf-thymus DNA have been measured in mole per mole of nucleotide as function of equilibrium protein concentration. We have exploited measurement of the surface tension of the protein solution in the presence and absence of DNA to calculate the binding ration (gammap). Interaction of bovine serum albumin with DNA has been studied at different pH. Interaction of bovine serum albumin with DNA has been studied at different pH, ionic strength and in presence of Ca2+. Interaction of BSA with denatured DNA has also been investigated. Binding isotherms for other globular proteins like beta-lactoglobulin, alpha-lactalbumin and lysozyme have been compared under identical physicochemical condition. It has been noted with considerable interest that globular form of protein is important to some extent in protein-DNA interaction. An attempt has been made to explain the significance of difference in binding ratios of these two biopolymers in aqueous medium for different systems in the light of electrostatic and hydrophobic effects. Values of maximum binding ration (gammap(m)) at saturated level for different systems have been also presented. The Gibb's free energy decrease (-deltaG0) of the binding of proteins to DNA has been compared more precisely for the saturation of binding sites in the DNA with the change of activity of protein in solution from zero to unity in the rational mole fraction scale.

Animals↗

PubMed2001

Alginate immobilization of Spirulina platensis for wastewater treatment.

Immobilization of cyanobacterium Spirulina platensis in sodium alginate (1.5 %) gave the best quality of bead and 15-16 beads were formed per mL of aqueous solution of alginate. The immobilized cells were used in a batch process for treatment of diluted sewage. After 8 days, 95 % of BOD5, 77 % of COD, 90 % of ammonia, and 94 % of TSS were removed.

Alginates↗

PubMed2000

Plasma exchange for the removal of digoxin-specific antibody fragments in renal failure: timing is important for maximizing clearance.

Life-threatening digoxin toxicity may be effectively treated with digoxin-specific antibody fragments (Fab). However, in end-stage renal disease, the digoxin-Fab complexes persist in the circulation and dissociate, potentially resulting in rebounding free digoxin levels and the recurrence of symptomatic toxicity. To prevent this rebound phenomenon, plasma exchange (PE) has been implemented for the removal of the digoxin-Fab complexes in renal failure. However, there is only one case report describing its use in this setting. To better determine the optimal timing of PE after Fab administration, we performed two PE treatments (each preceded by Fab) in a patient with acute renal failure and acute digoxin poisoning. The admission serum digoxin level was 21 ng/mL. The timing of the PE treatments relative to Fab dosing was as follows: the first PE was performed 26 hours post-Fab, and the second PE was performed 2.5 hours post-Fab. The plasma ultrafiltrate digoxin concentration was 2.5-fold greater when PE was performed 2.5 hours versus 26 hours after Fab administration (19.9 versus 8.1 ng/mL). The combined total amount of digoxin removed in the ultrafiltrate plasma was minimal (0.13 mg), less than 1% of the total amount of ingested drug. We conclude that the optimal timing of PE is within the first 3 hours after Fab administration. Although PE is efficacious for removing digoxin-Fab complexes, thus preventing rebound digoxin toxicity, it is not efficacious for improving total digoxin clearance because of the large apparent volume of distribution of digoxin (5 to 8 L/kg).

Acute Kidney Injury↗

PubMed2000

Compartment syndrome in a patient with X-linked agammaglobulinaemia and ecthyma gangrenosum. Case report.

Compartment syndrome is a surgical emergency that requires immediate decompression. We know of no documented cases that describe ecthyma gangrenosum as a primary cause of compartment syndrome. We present a case of a baby with x-linked agammaglobulinaemia who developed compartment syndrome associated with systemic Pseudomonas aeruginosa infection and ecthyma gangrenosum of the leg. He was treated by debridement and fasciotomies followed by primary closure and skin grafting and made an uneventful recovery.

Agammaglobulinemia↗

PubMed2000

A unique 33-kD cysteine proteinase accumulates in response to larval feeding in maize genotypes resistant to fall armyworm and other Lepidoptera.

Plants respond to insect feeding with a number of defense mechanisms. Using maize genotypes derived from Antiquan germ plasm that are resistant to Lepidoptera, we have demonstrated that a unique 33-kD cysteine proteinase accumulates in the whorl in response to larval feeding. The abundance of the proteinase increased dramatically at the site of larval feeding after 1 hr of infestation and continued to accumulate for as long as 7 days. The 33-kD cysteine proteinase was most abundant in the yellow-green portion of the whorl-the normal site of larval feeding and the tissue that has the greatest inhibitory effect on larval growth in bioassays. The proteinase was expressed in response to wounding and was found in senescent leaves. It may be a marker of programmed cell death. The gene coding for the proteinase, mir1, has been transformed into Black Mexican Sweet callus. When larvae were reared on callus expressing the proteinase, their growth was inhibited approximately 60 to 80%. The expression of a cysteine proteinase, instead of a cysteine proteinase inhibitor, may be a novel insect defense mechanism in plants.

Animals↗