Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0277787 (stigma)
 13,352 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thaumatin and 12 purified thaumatin-like (TL) proteins were surveyed for their capacity to hydrolyse beta-1,3-glucans by using an in-gel glucanase assay. Six TL proteins identified by N-terminal amino acid microsequencing were found to be active on carboxymethyl(CM)-pachyman: a barley leaf stress-related permatin, two tomato fruit osmotins, a cherry fruit and two tobacco stigma proteins. TL enzymes ranged in specific activity from 0.07 to 89 nkat mg-1 with CM-pachyman as substrate. Hydrolytic activities were not restricted to TL proteins strongly binding to water-insoluble beta-1,3-glucans since the two osmotins were active without tight binding to pachyman. Some TL proteins hydrolysed crude fungal walls and one barley TL enzyme even lysed fungal spores. No activity was observed on laminarin in the in-gel hydrolase assay. Thin-layer chromatography revealed that the six enzymes acted as endo-beta-1, 3-glucanases leading to the formation of various oligoglucosides. Thus far, the TL enzymes (EC 3.2.1.x) appeared different from the well-known beta-1,3-glucanases (EC 3.2.1.39). No activity was found with thaumatin, zeamatin, tobacco leaf PR-R protein and four stress-related TL proteins from barley and pea. This is the first demonstration that diverse TL proteins are enzymatically active. The functions of some TL proteins must be reassessed because they display endo-beta-1,3-glucanase activity on polymeric beta-1, 3-glucans.
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PMID:Some thaumatin-like proteins hydrolyse polymeric beta-1,3-glucans. 1050 69

The pollen grains of angiosperms are usually desiccated at maturity. Following pollination, pollen hydrates on the stigma surface before germination takes place. Rehydration is an essential step for the success of pollination and depends on the movement of water from the stigmatic cells. This water flow has been shown to be biologically regulated, and components of both pollen and stigma surfaces have been demonstrated to play a role in the control of pollen hydration. Regulation of water transport between animal or plant cells involves membrane proteins, designated aquaporins, which possess water-channel activity. Such molecules may be candidates for controlling pollen hydration, and consequently we investigated whether aquaporins are present in the pollen and stigma cells in Brassica oleracea. Here, we report the identification of two new aquaporin genes, Bo-PIP1b1 and Bo-PIP1b2, which are highly homologous to PIP1b from Arabidopsis thaliana. Both Bo-PIP1b1 and Bo-PIP1b2 proteins are active water channels when expressed in Xenopus oocytes. Expression of Bo-PIP1b1 and Bo-PIP1b2 was observed in reproductive organs as well as in vegetative tissues. Interestingly, the use of a Bo-PIP1b2 cDNA probe revealed that PIP1-like transcripts were not present in the pollen grains or in the stigma papillae, but were present in the stigma cell layers underlying the papillar cells. This observation suggests that water flow between the pollen and stigma papillae may be dependent on aquaporins expressed in cells that are not directly in contact with the pollen grain.
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PMID:Aquaporin PIP genes are not expressed in the stigma papillae in Brassica oleracea. 1106 97

In crucifers, the ability of the stigma to differentially modulate hydration of pollen grains, depending on whether the pollen is recognized to be compatible or incompatible, represents a crucial stage in pollination. Our recent analysis of the mod mutation of Brassica, which results in a breakdown of the self-incompatibility response, led to the isolation of a gene linked to the MOD locus which is expressed at low levels in mod mutants. The gene is predicted to encode a plasma membrane-localized aquaporin-like protein and has been designated MIP-MOD. We utilized reporter gene analysis to demonstrate that the MIP-MOD promoter is active in Brassica papillar cells as well as in some vegetative tissues. The encoded protein is also likely to be plasma membrane-localized based on the observation that all plasma membrane-intrinsic aquaporin-like proteins in Brassica leaves are enriched in plasma membrane fractions. The MIP-MOD protein results in a low but measurable enhancement in osmotic water permeability of Xenopus oocytes and hence represents a functional aquaporin. The results are consistent with the notion that MIP-MOD is involved in the regulation of water transport across the stigma epidermal cell membrane.
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PMID:The brassica MIP-MOD gene encodes a functional water channel that is expressed in the stigma epidermis. 1124 6

Researchers have determined that a $4 dose of Nevirapine, which is 70 times cheaper than a short course of AZT therapy, is more effective than the AZT treatment in reducing the transmission of HIV from mother to baby. About 1,800 infants are born each day with HIV infection, and an estimated 45 percent of pregnant women in South Africa will be infected by the end of the year. The Nevirapine therapy still remains too expensive for much of the world, and there are still many women who are not tested during pregnancy and do not know they are at risk of transmitting the disease. Because of the stigma, many African women decline testing even when it is free and treatment is available. A study in Uganda found that Nevirapine lowers the risk of HIV transmission by breast feeding by nearly 50 percent during a baby's first four months. Vertical transmission remains a difficult issue, especially where contaminated water supplies could put an infant at risk for other infections when they are fed formula mixed with contaminated water.
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PMID:Can a $4 drug stop vertical HIV transmission? 1136 85

There is strong evidence that aquaporins are central components in plant water relations. Plant species possess more aquaporin genes than species from other kingdoms. According to sequence similarities, four major groups have been identified, which can be further divided into subgroups that may correspond to localization and transport selectivity. They may be involved in compatible solute distribution, gas-transfer (CO2, NH3) as well as in micronutrient uptake (boric acid). Recent advances in determining the structure of some aquaporins gives further details on the mechanism of selectivity. Gating behaviour of aquaporins is poorly understood but evidence is mounting that phosphorylation, pH, pCa and osmotic gradients can affect water channel activity. Aquaporins are enriched in zones of fast cell division and expansion, or in areas where water flow or solute flux density would be expected to be high. This includes biotrophic interfaces between plants and parasites, between plants and symbiotic bacteria or fungi, and between germinating pollen and stigma. On a cellular level aquaporin clusters have been identified in some membranes. There is also a possibility that aquaporins in the endoplasmic reticulum may function in symplasmic transport if water can flow from cell to cell via the desmotubules in plasmodesmata. Functional characterization of aquaporins in the native membrane has raised doubt about the conclusiveness of expression patterns alone and need to be conducted in parallel. The challenge will be to elucidate gating on a molecular level and cellular level and to tie those findings into plant water relations on a macroscopic scale where various flow pathways need to be considered.
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PMID:Plant aquaporins: multifunctional water and solute channels with expanding roles. 1184 62

In this study, we have analysed ultrastructurally the mechanism of epithelial fusion and perforation during the development of branchial fissures in the larva and bud of the colonial urochordate Botryllus schlosseri. Perforation of membranes represents an important process during embryogenesis, occurring to create communication between two separate compartments. For example, all chordate embryos share the formation of pharyngeal plates, which are constituted of apposed endodermal and ectodermal epithelia, which have the capacity to fuse and perforate. Although the process of perforation is extremely common, its cellular mechanism remains little understood in detail, because of the complexity of the structures involved. In B. schlosseri, two epithelial monolayers, the peribranchial and the branchial ones, with no interposed mesenchymal cells, participate in pharyngeal perforation. Blood flows in the interspace between the two cellular leaflets. Apico-lateral zonulae occludentes seal the cells of each epithelium, so that the blood compartment is separated from the environment of the peribranchial and branchial chambers; here, sea water will flow when the zooid siphons open. Stigmata primordia appear as contiguous thickened discs of palisading cells of branchial and peribranchial epithelia. The peribranchial component invaginates to contact the branchial one. Here, the basal laminae intermingle, compact, and are degraded, while the intercellular space between the two epithelia is reduced to achieve the same width as that found between the lateral membranes of adjacent cells. Cells involved in this fusion rapidly change their polarity: they acquire a new epithelial axis, because part of the adhering basal membrane becomes a new lateral surface, whereas the original lateral membranes become new apical surfaces. Before disassembling the old tight junctions and establishing communication between branchial and peribranchial chambers, cells of the stigmata rudiments form new tight junctions organised as distinct entities, so that the structural continuum of the epithelial layers is maintained throughout the time of fusion and perforation.
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PMID:Cell reorganisation during epithelial fusion and perforation: the case of ascidian branchial fissures. 1211 60

There are about 20 epidemiological studies on epilepsy from different parts of India. They include both rural and urban studies. The prevalence rate stands at around 5/1000 population (at this rate present estimate of total epileptics in this country is about 5 million) and incidence rate varies from 38 to 49.3 per 100,000 population per year from two community-based studies in India. Case-control studies indicate that febrile seizures, family history of epilepsy and head trauma are significant risk factors. Type of seizure pattern showed maximum number of cases belonged to generalised seizures which is different from Western countries where partial seizure is the commonest variety. Treatment gap, which is a measure of per cent of patient populations not receiving the treatment, estimated to be up to 73.7% to 78% in India. Aetiology is unknown in about two-thirds of cases. Hot water epilepsy is unique in South India and single solitary ring enhancing lesion in brain imaging is a common feature in Indian subcontinent. Evaluation of prevalence study indicates that more case-control studies to find out the aetiology, pharmaco-economic study to find out the affordable drug for general public and mass health education should be undertaken to dispel the social stigma and to bring about change in the attitude about the disease.
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PMID:Epidemiology of epilepsy--Indian perspective. 1241 36

Epilepsy is a common disease found in 2% of the population, affecting both young and old. Unfortunately, epileptics have previously been discouraged from participation in physical activity and sports for fear of inducing seizures or increasing seizure frequency. Despite a shift in medical recommendations toward encouraging rather than restricting participation, the stigma remains and epileptics continue to be less active than the general population. This results in increased body mass index, decreased aerobic endurance, poorer self-esteem, and higher levels of anxiety and depression. Although there are rare cases of exercise-induced seizures, studies have shown that physical activity can decrease seizure frequency, as well as lead to improved cardiovascular and psychologic health. The majority of sports are safe for epileptics to participate in with special attention to adequate seizure control, close monitoring of medications, and preparation of family, coaches, or trainers. Contact sports including football, hockey, and soccer have not been shown to induce seizures, and epileptics should not be precluded from participation. Water sports and swimming are felt to be safe if seizures are well controlled and direct supervision is present. Additional care must be taken in sports involving heights such as gymnastics, harnessed rock climbing, or horseback riding. Sports such as hang-gliding, scuba diving, or free climbing are not recommended, given the risk of severe injury or death, if a seizure were to occur during the activity. This article reviews the risks and benefits of physical activity in epileptics, discusses sports in which epileptics may participate, and addresses how to decrease possible risks for injury.
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PMID:Epilepsy and sports participation. 1472 9

The corm size of Crocus sativus, a well-known medicine, is a key limiting factor for its stigma harvest. A water cultural experiment with four different potassium (K) concentrations showed that the K content, chlorophyll content, relative ATP content and net photosynthetic rate in C. sativus leaves increased with improving K concentration, which enhanced the function of leaves to be metabolic source. On the other hand, the K absorbing ability and the contents of soluble sugars, vitamin C (Vc) and protein in new-born corms were increased with improving K concentration, which also strengthened the function of new-born corms to be metabolic sink. This study also showed that K could promote the new-born corm growth rate of C. sativus through strengthening the function of "source" and "sink".
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PMID:[Physiological and ecological effects of potassium on expansion of crocus corm]. 1533 66

Several processes during sexual reproduction in higher plants involve the movement of water between cells or tissues, such as occurs during dehiscence of the anther and hydration of the pollen grain after it is deposited on a stigma. To get more insight in these processes, a set of putative aquaporins was cloned and it was found that at least 15 are expressed in reproductive organs, which indicates that the control of water flow is important for reproduction. Functional studies in Xenopus laevis oocytes using two of the cDNAs showed that NtPIP2;1 is an efficient aquaporin, whereas NtPIP1;1 is not. Expression studies on RNA and protein levels showed that PIP1 and PIP2 genes are differently expressed in reproductive organs: PIP1 RNA accumulates in the stigma, and PIP1 and PIP2 RNA can be detected in most tissues of the anther.
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PMID:PIP1 and PIP2 aquaporins are differentially expressed during tobacco anther and stigma development. 1552 27


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