Biomanagement of rice root-knot nematode Meloidogyne graminicola using five indigenous microbial isolates under pot and field trials

AIMS

To ascertain the effectiveness of Aspergillus niger, Trichoderma harzianum, Pochonia chlamydosporia, Bacillus subtilis and Pseudomonas fluorescens against rice root-knot nematode, Meloidogyne graminicola, and to optimize their application methods.

METHODS AND RESULTS

The relative effectiveness of five indigenous biocontrol agents (BCA) against M. graminicola on rice cv. PS-5 was tested initially in pot culture. The BCAs, A. niger, P. chlamydosporia and P. fluorescens proved more effective, and significantly reduced the nematode disease. It is hypothesized that success of a biocontrol module may vary with the BCA and application methods. Hence, the effectiveness of the above three BCAs as well as seven different treatment schemes were evaluated in naturally infested farmer's fields during 2 consecutive years. In nematode-infested plots without any BCA treatments, terminal galls formed on the roots, and plants suffered a 19-31% decrease in the growth and yield. The treatments with P. chlamydosporia or A. niger through root-dip (RD) plus one soil application (SA) at 15 days after planting were found to be highly effective against the nematode.

CONCLUSIONS

Relatively greater nematode control was achieved with RD plus two SAs (15 + 30 DAP) but statistically the effect was on par with RD + one SA at 15 DAP. These treatments significantly reduced galling (22-25%), egg mass production (21-29%) and reproduction factor (63-70%) of M. graminicola, and subsequently increased the grain yield (11-21%).

SIGNIFICANCE AND IMPACT OF THE STUDY

Application methods enhanced the effectiveness of BCAs against M. graminicola. The RD plus one SA at 15 DAP proved to be most effective treatment to control root-knot disease in rice. Use of multiple treatments (root dip and SA) appears cumbersome, but in view of effectiveness and limitation of chemical control in rice paddies, farmers may adopt the above module that may lead to 11-21% yield improvement.

Occipital somites guide motor axons of the accessory nerve in the avian embryo

The accessory nerve (nervus accessorius) displays a unique organization in that its axons ascend along the rostrocaudal axis after exiting the cervical spinal cord and medulla oblongata and thereafter project ventrally into the periphery at the first somite level. Little is known about how this organization is achieved. We have investigated the role of somites in the guidance of motor axons of the accessory nerve using heterotopic transplantations of somites in avian embryos. The formation of not only accessory nerve but also the vagal nerve was affected, when a more caudal occipital somite (somites 2-4) was grafted to the position of the first occipital somite. Our study reveals that only the first occipital somite permits the development of ventral projection of accessory axons, a process that is inhibited by more caudal occipital somites.

Drinking water: a major source of lead exposure in Karachi, Pakistan

Excess lead in drinking water is a neglected source of lead toxicity in Pakistan. A cross-sectional survey in 2007/08 was made of water samples from drinking water sources in Karachi, a large industrial city. This study aimed to compare lead levels between untreated ground water and treated surface (tap) water in 18 different districts. Of 216 ground and surface water samples collected, 86% had lead levels higher than the World Health Organization maximum acceptable concentration of l0 ppb. Mean lead concentration in ground water [146 (SD 119) ppb] was significantly higher than in surface water [77.1 (SD 54) ppb]. None of the 18 districts had a mean lead level of ground or surface water below the WHO cut-off and ground water sources in 9 districts had a severe level of contamination (>150 ppb). Urgent action is needed to eliminate sources of contamination.

Wilms tumor in adult

Wilms Tumor (WT) is a very rare malignancy in adults representing 1% of all renal neoplasms. It is however the most common renal tumor of children and adult patients are treated like pediatric cases. Bilateral tumors occur in 5% of adult cases. The typical presenting features are asymptomatic abdominal mass (most common), hematuria, pain, fever, and hypertension. As clinical presentation of WT is similar to that of renal cell carcinoma (RCC), it tends to be an unsuspected pathological diagnosis in most cases. The diagnosis of the tumor needs positive sonographic and computed tomography (CT) findings with histopathological confirmation. Prognosis of adult WT is relatively poor and resistant to chemotherapy. We present a case of wilms tumor in a 68 years old male patient with right sided non tender abdominal mass and occasional flank pain. The patient was normotensive but hematuric and radiological findings suggested right renal mass with enlarged lymph node and histopathological analysis revealed nephroblastoma associated with lymph node metastases.

Immunoglobulin (Ig)-containing plasma cells in the Harderian gland in broiler and native chickens of Bangladesh

The distribution and frequency of immunoglobulin (Ig)-containing plasma cells, their variations due to sex, and the mode of secretion of Ig cells into the duct system of the Harderian gland was investigated in broiler and native chickens of both sexes in Bangladesh. The Harderian gland is covered by a capsule, and the connective tissue septa divide the gland into numerous unequal-sized numerous lobes and lobules. The Ig-containing plasma cells were located in the interstitial space, interacinar space, apical part of the lobule, and lumina of the lobules of the Harderian gland in both broiler and native chickens. The population of these Ig-containing plasma cells varied in between broiler and native chickens, and also between male and female broiler and native chickens. In the broiler, the number of IgM-containing plasma cells was higher; in contrast, in the native chickens, the population of IgA-containing plasma cells was larger. In the broiler, there were more IgA- and IgG-containing plasma cells in the male; in contrast, there were more IgM-containing plasma cells in female. In native chickens the frequency of IgA-containing plasma cells was greater in the female than male. When the data for broiler and native birds were compared, it was found that there were significantly more IgA- and IgG-containing plasma cells in the native male and female chickens than in the broiler males and females. The secretory Igs were located in the lumina of acini and the duct system of the Harderian gland. In the present study Ig-containing plasma cells were observed to be released in the lumina of the lobules of Harderian gland by the breakdown of acinar tissues in broilers, and by holocrine mode of secretion in the native chicken. These results suggested that the Harderian gland, even though it is not a lymphoid organ as a whole, but acts as an immunopotent organ in chickens, and that the gland in native chicken contains more Ig-containing plasma cells due to their scavenging.

The prevalence of glaucoma in Bangladesh: a population based survey in Dhaka division

BACKGROUND/AIM

Few studies have reported on the epidemiology and clinical characteristics of glaucoma in south Asia. This project aimed to determine the prevalence of glaucoma of Dhaka, Bangladesh.

METHOD

A multistage, stratified, clustered sample was drawn from Dhaka Division, Bangladesh, using systematic sampling to identify individual subjects aged 35 years and older. Examination of all subjects included Snellen visual acuity, slit lamp examination (including gonioscopy and applanation tonometry) and a stereoscopic assessment of the vertical cup:disc ratio (CDR). In selected subjects, a threshold visual field examination was performed. Glaucoma was diagnosed on the basis of statistical abnormality of the vertical CDR combined with an abnormal visual field test, or in subjects with advanced glaucoma who could not complete field testing, a grossly abnormal CDR. If it was not possible to examine the optic discs and the subject was blind, glaucoma was diagnosed on the basis of a raised intraocular pressure.

RESULTS

Of 3562 eligible subjects, 2347 were examined (66%). Among people aged 40 years and older, the prevalence of definite glaucoma was 2.1% (95% confidence interval: 1.5 to 2.9; 39 people). The prevalence of definite and probable glaucoma was 3.1% (95% CI: 2.4 to 4.0; 58 people) in subjects of the same age. Primary open angle glaucoma was the most common form of glaucoma, accounting for 75% of the total. Among cases of blindness not attributable to refractive error, 5% were caused by glaucoma. Glaucoma prevalence was higher in men than women, but did not show the typical increase with age.

CONCLUSION

Glaucoma prevalence is relatively high in Bangladesh, although it accounts for only a small proportion of blindness in the community. It is estimated that there are approximately 586 000 people 40 years and older with definite or probable glaucoma in Bangladesh.

Metabolic and stress responses of the body to trauma: produced by the laparoscopic and open cholecystectomy

Laparoscopic cholecystectomy is regarded as gold standard therapy for symptomatic gall stone disease. This study was done to compare the metabolic and stress responses between open and lapraroscopic cholecystectomy and to evaluate their significance in postoperative recovery. Thirty patients with symptomatic gall stone disease were treated with open and laparoscopic cholecystectomy on elective basis (14 versus 16). Three samples of blood were collected from each patient to investigate serum cortisol, adrenaline, nor-adrenaline, C-reactive protein and blood glucose level. The mean age of patients was 41.86+/-10.13 blood glucose and stress hormones (cortisol, adrenaline, nor adrenaline) and C-reactive protein all were found significantly raised in the postoperative period in open cholecystectomy than laparoscopic cholecystectomy group. The postoperative recovery was also prolonged in the open group. The obvious clinical advantages of laparoscopic cholecystectomy over open cholecystectomy is mainly because of less metabolic and stress response.

Hypoxia-induced respiratory patterned activity in Lymnaea originates at the periphery

Respiration in Lymnaea is a hypoxia-driven rhythmic behavior, which is controlled by an identified network of central pattern generating (CPG) neurons. However, the precise site(s) (i.e., central or peripheral) at which hypoxia acts and the cellular mechanisms by which the respiratory chemosensory drive is conveyed to the CPG were previously unknown. Using semi-intact and isolated ganglionic preparations, we provide the first direct evidence that the hypoxia-induced respiratory drive originates at the periphery (not within the central ring ganglia) and that it is conveyed to the CPG neurons via the right pedal dorsal neuron 1 (RPeD1). The respiratory discharge frequency increased when the periphery, but not the CNS, was made hypoxic. We found that in the semi-intact preparations, the frequency of spontaneously occurring respiratory bursts was significantly lower than in isolated ganglionic preparations. Thus the periphery exerts a suppressive regulatory control on respiratory discharges in the intact animal. Moreover, both anoxia (0% O(2)) and hypercapnia (10% CO(2)) produce a reduction in respiratory discharges in semi-intact, but not isolated preparations. However, the effects of CO(2) may be mediated through pH changes of the perfusate. Finally, we demonstrate that chronic exposure of the animals to hypoxia (90% N(2)), prior to intracellular recordings, significantly enhanced the rate of spontaneously occurring respiratory discharges in semi-intact preparations, even if they were maintained in normoxic saline for several hours. Moreover, we demonstrate that the peripherally originated hypoxia signal is likely conveyed to the CPG neurons via RPeD1. In summary, the data presented in this study demonstrate the important role played by the periphery and the RPeD1 neuron in regulating respiration in response to hypoxia in Lymnaea.

CREB-binding protein is a nuclear integrator of nuclear factor-kappaB and p53 signaling

Transcriptional coactivators may function as nuclear integrators by coordinating diverse signaling events. Here we show that the p65 (RelA) component of nuclear factor-kappaB (NF-kappaB) and p53 mutually repress each other's ability to activate transcription. Additionally, tumor necrosis factor-activated NF-kappaB is inhibited by UV light-induced p53. Both p65 and p53 depend upon the coactivator CREB-binding protein (CBP) for maximal activity. Increased levels of the coactivator relieve p53-mediated repression of NF-kappaB activity and p65-mediated repression of p53-dependent gene expression. Nuclear competition for limiting amounts of CBP provides a novel mechanism for altering the balance between the expression of NF-kappaB-dependent proliferation or survival genes and p53-dependent genes involved in cell cycle arrest and apoptosis.

Collagen cross-linking in sun-exposed and unexposed sites of aged human skin

A recently described nonreducible, acid-heat stable compound, histidinohydroxylysinonorleucine (HHL), is a collagen cross-link isolated from mature skin tissue. Its abundance is related to chronologic aging of skin. The present communication describes the quantity of HHL from aged human skin of the same individuals in sun-exposed (wrist) and unexposed (buttock) sites. Punch biopsies were obtained from these sites from nine people of age 60 or older. HHL contents (moles/mole of collagen) at these sites were for wrist 0.13 +/- 0.07 and for buttock 0.69 +/- 0.17 (mean +/- SD, p less than 0.001). In addition, it was found that acute irradiation of the cross-linked peptides with UVA (up to 250 J/cm2) and UVB (up to 1 J/cm2) had no effect on HHL structure. The same treatment significantly degraded another nonreducible, stable collagen cross-link, pyridinoline. The results suggest that chronic sunlight exposure may be associated with an impediment to normal maturation of human dermal collagen resulting in tenuous amount of HHL. Thus, the process of photoaging in dermal collagen is different from that of chronologic aging in human skin.

Effect of malnutrition and subsequent rehabilitation on the development of mouse brain myelin

Malnutrition in mice from birth resulted in myelin of brain having higher than normal molar proportions of cholesterol and phospholipids relative to a molar unit of cerebroside + sulphatide. This was found at all ages between 20 and 60 days, and the molar ratio of these lipids in older animals was comparable to that in the younger controls. The phospholipid and the ganglioside patterns were also immature for age. The phospholipid composition was characterized by lower molar proportions of ethanolamine phosphoglyceride (EPG) and sphingomyelin (SPh) and higher proportion of choline phosphoglyceride (CPG), and the ganglioside pattern was characterized by higher molar proportions of the disialogangliosides GD1a and GD1b and markedly lower proportion of the monosialoganglioside GM1. Malnutrition imposed from 30 days of age did not affect the contents of the major lipids (and so their molar ratio), but within the phospholipids there was a small but significant deficit of SPh, which was compensated by a higher content of CPG. The ganglioside pattern was as if the animals were malnourished from birth. Nutritional rehabilitation up to 60 days of age subsequent to malnutrition for the first 30 days fully corrected the ganglioside pattern, but not the molar ratio, of the major lipids (because of persistent deficit in cerebroside + sulphatide) and the composition of the phospholipids (because of small but significant deficit of SPh). The results indicate that malnutrition instituted at any time during the entire programme of myelination can affect one or other aspect of myelin development, and nutritional rehabilitation of animals malnourished in early life cannot fully correct this developmental gap.