Comparative cryopreservation of indian wild orange (Citrus indica Tanaka) embryonic axes.

BACKGROUND: Indian Wild Orange (Citrus indica Tanaka) is an endangered and endemic species from northeast India for which effective ex situ conservation strategies, including embryo cryopreservation, are urgently needed. MATERIALS AND METHODS: Desiccation tolerance and cryopreservation ability for embryonic axes of Citrus indica was determined using three techniques (air desiccation-freezing, PVS2 vitrification-freezing and encapsulation-dehydration-freezing). Success was assessed as survival and recovery in vitro. RESULTS: Successful cryopreservation of embryonic axes was achieved using all three methods, with the highest survival achieved when using air desiccation-freezing (90%) followed by encapsulation-dehydration (85%) and PVS2 vitrification cryopreservation (80%). Regeneration levels were lower than survival levels for all three proceedures. Post-cryo regeneration success was: encapsulation-dehydration (64%) > air desiccation-freezing (55%) > PVS2 vitrification (52%). CONCLUSION: Although there was relatively high post-cryopreservation recovery growth obtained using all the three techniques, the air desiccation-freezing technique is preferred, as it is a simple, practical and reproducible technique for the long-term cryobanking of this important wild species. Doi: 10.54680/fr23310110512.

Storage Behavior and Cryopreservation of Citrus cavaleriei, an Endangered, Cold-resistant Species of Northeast India with Exceptionally Large Seeds.

BACKGROUND: Ichang Papeda (Citrus cavaleriei H.Lév. ex Cavalerie) is a wild and endangered species of NE India that requires urgent preservation of its genetic resources. OBJECTIVE: To characterize the storage physiology of the seeds and to cryopreserve the embryo and embryonic axis (EA). MATERIALS AND METHODS: The morphology and storage physiology of the seeds were determined, and the cryopreservation of embryos and EA attempted using various techniques (viz., air desiccation-freezing, vitrification and encapsulation-dehydration). RESULTS: Weighing up to 4 g, seeds of Citrus cavaleriei are the largest known in the genus. Based on estimates using the seed coat ratio - seed mass (SCR-SM) model there was a very high probability of seed desiccation intolerance, which was validated physiologically; seeds lost vigour on drying below 30% moisture content (MC) and no seeds germinating after drying to <12% MC. Embryos and EAs could be air dried to 25-30% MC and cryopreserved with c. 50% survival. In contrast, EA optimally exposed to PVS2 (20 min) or encapsulated, sucrose pretreated (0.5 M, 24 h) and dehydrated (6 h) had c. 40% survival after cryopreservation. CONCLUSION: Citrus cavaleriei produces large, recalcitrant seeds that can, nevertheless, be cryopreserved as embryos or isolated EA after air drying to c. 25-30% MC; encapsulation-dehydration and vitrification provide alternative options for the cryopreservation of EA.

Long-term, large scale banking of citrus species embryos: comparisons between cryopreservation and other seed banking temperatures.

The long-term, large scale application of embryo cryopreservation has been assessed rarely and comparisons of viability loss for partially dried material with conventional seed bank storage conditions infrequently made. Five citrus species were cryopreserved following air drying of embryos (seed minus the testa) and embryonic axes: rough lemon (Citrus jambhiri), pommelo (C. grandis), mandarin (C. reticulata), citron (C. medica) and kagzi lime (C. aurantifolia). Although drying rates to c. 10 percent moisture content (MC) were approximately 10-times faster for isolated axes compared to embryos, the optimum MCs for cryopreservation were generally similar within a species, varying from c. 10 percent (C. jambhiri) to c. 20 percent (C. medica). Nonetheless, the hydration window for cryopreservation of the axis was usually wider than for the embryo. For all species, embryo or axis survival after cryopreservation ranged from 65 to 96 percent (C. medica axes), producing normal healthy seedlings from embryos and plantlets from axes without intervening callus growth in vitro. Whilst partially dried embryos of all five species survived fully liquid nitrogen vapour storage for 120 days, viability loss was rapid at -20 degree C, 5 degree C and ambient temperature, with a maximum interpolated half-life across these temperatures of c. 80 days for C. grandis at 5 degree C. The developed cryopreservation protocols were applied routinely to cryobank 377 accessions of Citrus germplasm from field genebanks, farmer's orchards, semi-wild and wild sources. After an average of 6.3 to 8.4 years cryo-storage, between 69 and 81 percent of accessions per species retained > 70 percent of the viability after desiccation. The results provide irrevocable evidence for the importance of cryopreservation for the banking of seeds of higher plants.

Magnetic and magnetocaloric properties of nanocrystalline Pr(1-x)A(x)Mn(1-y)Co(y)O3 (A = Ca, Sr) (x = 0.3; y = 0.5) manganites.

Structural, magnetic and magnetocaloric properties of sol-gel prepared, nanocrystalline oxides Pr(1-x)A(x)Mn(1-y)Co(y)O3 (A = Ca, Sr) (x = 0.3; y = 0.5) (cubic, space group Fm3m) have been studied. From the X-ray data, the crystallite size of Pro.7Ca0.3Mn0.5Co0,503 and Pr0.7Sr0.3Mn0.5Co0.5O3 samples is found to be approximately 24 nm and approximately15 nm respectively. High resolution transmission electron microscopy image shows average particle size of approximately 34 nm and approximately 20 nm. Magnetization measurements indicate a Curie temperature of approximately 153 K and approximately172 K in applied magnetic field of 100 Oe for Pr0.7Ca0.3Mn0.5Co0.5O3 and Pr0.7Sr0.3Mn0.5Co0.O3 compounds. The magnetization versus applied magnetic field curves obtained at temperatures below 150 K show significant hysteresis and magnetization is not saturated even in a field of 7 T. The magnetocaloric effect is calculated from M versus H data obtained at various temperatures. Magnetic entropy change shows a maximum near T(c) for both the samples and is of the order approximately 2.5 J/kg/K.

An improved pollen collection and cryopreservation method for highly recalcitrant tropical fruit species of mango (Mangifera indica L.) and litchi (Litchi chinensis Sonn.).

An improved method for pollen collection from freshly dehiscing anthers of mango (Mangifera indica L.) and litchi (Litchi chinensis Sonn.) using the organic solvent cyclohexane has been devised. Using this method pollen quantity sufficient for large scale pollinations could be collected and stored for future use. Transport of pollen in viable conditions over long distances, from site of collection (field genebank) to cryolab was successfully devised for both these fruit species. Cryopreservation was successfully applied to achieve long-term pollen storage over periods of up to four years. Pollen viability was tested using in vitro germination, the fluorochromatic reaction (FCR) method and by fruit set following field pollination. On retesting, four year cryostored pollen of different mango and litchi varieties showed high percentage viability as good as fresh control pollens. Pollens of more than 180 cultivars of mango and 19 cultivars of litchi have been stored in the cryogenebank using the technology developed, thus facilitating breeding programmes over the long-term.

Improved critical current density of MgB2--carbon nanotubes composite.

In the present study, we report a systematic study of doping/admixing of carbon nanotubes (CNTs) in different concentrations in MgB2. The composite material corresponding to MgB2-x at.% CNTs (35 at.% > or = x > or = 0 at.%) have been prepared by solid-state reaction at ambient pressure. All the samples in the present investigation have been subjected to structural/microstructural characterization employing XRD, Scanning electron microscopic (SEM), and Transmission electron microscopic (TEM) techniques. The magnetization measurements were performed by Physical property measurement system (PPMS) and electrical transport measurements have been done by the four-probe technique. The microstructural investigations reveal the formation of MgB2-carbon nanotube composites. A CNT connecting the MgB2 grains may enhance critical current density due to its size (approximately 5-20 nm diameter) compatible with coherence length of MgB2 (approximately 5-6 nm) and ballistic transport current carrying capability along the tube axis. The transport critical current density (Jct) of MgB2 samples with varying CNTs concentration have been found to vary significantly e.g., Jct of the MgB2 sample with 10 at.% CNT addition is approximately 2.3 x 10(3) A/cm2 and its value for MgB2 sample without CNT addition is approximately 7.2 x 102 A/cm2 at 20 K. In order to study the flux pinning effect of CNTs doping/ admixing in MgB2, the evaluation of intragrain critical current density (JJ) has been carried out through magnetic measurements on the fine powdered version of the as synthesized samples. The optimum result on Jc is obtained for 10 at.% CNTs admixed MgB2 sample at 5 K, the Jc reaches approximately 5.2 x 10(6) A/cm2 in self field, -1.6 x 10(6) A/cm2 at 1 T, approximately 2.9 x 10(5) A/cm2 at 2.6 T, and approximately 3.9 x 10(4) A/cm2 at 4 T. The high value of intragrain Jc in 10 at.% CNTs admixed MgB2 superconductor has been attributed to the incorporation of CNTs into the crystal matrix of MgB2, which are capable of providing effective flux pinning centres. A feasible correlation between microstructural features and superconducting properties has been put forward.

Morphohistobiochemical characteristics of embryogenic and nonembryogenic callus cultures of sweet potato (Ipomoea batatas L.).

Ipomoea batatas callus culture raised in a medium supplemented with 2,4-D (2,4-dichlorophenoxy acetic acid) alone or 2,4-D in combination with benzyl adenine, were found to be embryogenic. Supplementation of exogenous chemicals, such as 5 g/l NaCI or 0.7 g/l proline together with a mild dose of 0.2 mg/l 2,4-D, enhanced somatic embryogenesis significantly in all the genotypes tested. Morphological, growth, physiological, histological, and biochemical characteristics of the embryogenic callus were different from the nonembryogenic callus. The former was compact, slow growing, and nodular compared with the fast growing, fragile, nonembryogenic callus. The embryogenic callus tissue had more dry matter, protein and reducing sugar contents compared with the less embryogenic callus. The somatic embryogenic response remained steady in the cultures for up to 96 weeks.

Plant regeneration via somatic embryogenesis in pigeonpea (Cajanus cajan L. Millsp).

Efficient plant regeneration via somatic embryogenesis has been developed in pigeonpea. Cotyledon and leaf explants from 10-day-old seedlings produced embryogenic callus and somatic embryos when cultured on Murashige and Skoog (MS) medium supplemented with 10 µM thidiazuron (TDZ). Subsequent withdrawal of TDZ from the induction medium resulted in the maturation and growth of the embryos into plantlets on MS basal medium. The rooted plantlets were transferred and acclimatized on vermiculite where they showed normal morphological characters.

Plant regeneration from various expiants of cultivated Piper species.

Morphogenetic potential of root, leaf, node and internode expiants of 3 cultivated Piper species was investigated to develop a reliable plant regeneration protocol. P. longum (pipli) was the most responsive followed by P. betle (betel vine) and P. nigrum (black pepper). In P. longum the highest number of shoot buds was produced on root expiants followed by node, internode and leaf expiants. In P. betle and P. nigrum adventitious shoot buds differentiated only from internodal and nodal ring regions, respectively. Histological examination in P. longum showed that adventitious shoot buds originate directly from the cortical cells of the root and the internode without an intervening callus phase. Benzyladenine was superior to kinetin for shoot induction and its optimum concentrations for P. longum, P. betle and P. nigrum were 1-2, 10 and 10 µM, respectively. Shoot elongation and rooting were achieved in B5 medium containing 0.5 µM benzyladenine and 1 µM indoleacetic acid, respectively. Regenerated plants were established in soil.

The epidemiology of tuberculosis in Bahrain.

Incidence and mortality from tuberculosis in Bahrain have been examined for the years 1965, 1971, 1980-1981 and 1983-1987. Both incidence and mortality rates have shown a large decline since 1965. Most of the decrease in incidence rates occurred in the period 1983-1987 when there was a sharp decline among non-Bahrainis by an average of 20.4% per annum, from 157.3 per 100,000 in 1983 to 63.1 per 100,000 in 1987. Rates for Bahrainis have decreased gradually since 1965 and during 1983-1987 declined from 15.8 per 100,000 to 11.9 per 100,000; an average annual decline of 6.8%. In 1983-1987, non-Bahrainis showed, on average, rates which were seven times higher than Bahrainis. In 1987, among Bahrainis the age distribution of cases shifted to older age groups in comparison to previous years, and in all the study years, there were more males with pulmonary tuberculosis than females. Rates for non-pulmonary tuberculosis showed only small fluctuations during the study period.

Congenital bronchial cyst.

A case of congenital bronchial cyst in a young female is reported. Relevant literature has been reviewed.

Fine needle aspiration cytology of intrathoracic lesions--a repraisal.

FNAC was performed in 186 cases. Inadequate material was obtained in 41 cases. A definite diagnosis of malignancy could be made in 120 cases. In five cases a diagnosis "suspicious" of malignancy could be made. No serious complication was encountered with the technique. FNAC is of definite help in diagnosing the intra thoracic lesion whether malignant or inflammatory in nature. It also avoids unnecessary thoracotomy for diagnostic purposes.

Gastric metastasis and ectopic amylase production in bronchogenic carcinoma.

A case of small cell anaplastic carcinoma of bronchus is described. Primary tumour had metastasized in the stomach and there was production of amylase by the tumour evidenced by raised serum amylase and pleural fluid amylase.

Pulmonary hydatid disease presenting as non-resolving bilateral consolidations.

A 45-year-old female, post menopausal, presented with extensive bilateral radiological opacities in the lungs. Diagnosis of hydatid diseases was confirmed through open lung biopsy. Treatment with albendazole showed striking improvement in clinical symptoms as well as clearing of radiological shadows.

Combination chemotherapy in inoperable lung cancer--a trial of 2 regimens.

Combination chemotherapy with 3 drugs (vincristine + cyclo-phosphamide + methotrexate of adriamycin) were administered to 36 cases of advanced bronchogenic carcinoma. The median survival for patients with small cell carcinoma (SCC) was 24.5 weeks whereas that for non small cell carcinoma was 27.5 weeks (P greater than 0.05). Fifty-five per cent of the patients survived beyond 6 months; 30.5 per cent survived beyond 1 year and 11 per cent of the patients survived beyond two years. Adriamycin did not prove more effective than methotrexate. However, omission of adriamycin from the regimen may reduce the cost of chemotherapy.

Factors influencing the cellular response in bronchoalveolar lavage and peripheral blood of patients with pulmonary tuberculosis.

Subsegmental bronchoalveolar lavage was performed in 30 patients with active pulmonary tuberculosis and six control subjects. Total leucocyte count, absolute lymphocyte count, count of polymorphonuclear leucocytes, T and B lymphocytes were determined in peripheral venous blood. These parameters and macrophage counts were also determined in bronchoalveolar lavage fluid. Variations in the cellular responses were correlated with patients' age, sex, nutritional status and duration of symptoms as well as radiological severity of disease. Patients of both sexes (seven female) showed similar responses. Decreased cell counts in peripheral blood were observed in patients aged 31 to 40 years. Well-nourished patients (n = 19) had higher counts of lymphocytes in peripheral blood and polymorphonuclear leucocytes in bronchoalveolar lavage fluid. The duration of symptoms had a significant influence on cellular responses. In blood, lymphocyte counts were increased in those with symptoms of shorter duration but reduced in those symptomatic for more than 6 months. In bronchoalveolar lavage fluid also all cellular elements were increased in those symptomatic for less than 6 months but a decline followed in those with symptoms for longer duration. Patients with minimal disease radiologically showed higher total leucocyte counts in blood, whereas those with moderately advanced lesions had elevated absolute lymphocyte counts. T cell lymphopenia was observed in blood of patients with far advanced disease. The inflammatory response in bronchoalveolar lavage fluid, however, increased in parallel with the severity of disease. Patients with far advanced lesions showed marked inflammation irrespective of duration of symptoms. Thus, the pattern of inflammation in bronchoalveolar lavage fluid was not similar to that in peripheral blood, particularly in patients with far advanced lesions.

Single dose kinetics of rifampicin and isoniazid in well-nourished and malnourished patients of tuberculosis.

A single dose kinetics of isoniazid and rifampicin alone, and combination was studied in well-nourished and malnourished patients of tuberculosis. The elimination half-life of isoniazid was significantly increased when administered in combination with rifampicin in well-nourished and malnourished patients, while no significant difference was observed in any of the pharmacokinetic parameters of rifampicin in combination with isoniazid or alone in both groups of patients. Results are discussed on the basis of pharmacokinetic drug interaction.

False-positive reactions with enzyme-linked immunosorbent assay of Mycobacterium tuberculosis antigens in pleural fluid.

The value of enzyme-linked immunosorbent assay (ELISA) for the diagnosis of tuberculous pleural effusion has not been defined. We performed ELISA by a double antibody sandwich technique with anti-BCG antibody in the solid phase to detect Mycobacterium tuberculosis antigen in pleural fluid from 36 patients with pleural effusion (tuberculosis 15, lung cancer 12, miscellaneous 9). Pleural fluids from 12 of the tuberculosis patients, 12 of the cancer patients and one patient in the miscellaneous group had optical densities above the cut-off point. False-positive reactions in patients with lung cancer limit the usefulness of ELISA with conventional anti-BCG antibody for detection of M. tuberculosis antigen.