Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0022568 (keratitis)
 5,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

(E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU, Brivudin, Zostex, Zerpex, Zonavir), now more than 20 years after its discovery, still stands out as a highly potent and selective inhibitor of herpes simplex virus type 1 (HSV-1) and varicella-zoster virus (VZV) infections. It has been used in the topical treatment of herpetic keratitis and recurrent herpes labialis and the systemic (oral) treatment of herpes zoster (zona, shingles). The high selectivity of BVDU towards HSV-1 and VZV depends primarily on a specific phosphorylation of BVDU to its 5'-diphosphate (DP) by the virus-encoded thymidine kinase (TK). After further phosphorylation (by cellular enzymes), to the 5'-triphosphate (TP), the compound interferes as a competitive inhibitor/alternate substrate with the viral DNA polymerase. The specific phosphorylation by the HSV- and VZV-induced TK also explains the marked cytostatic activity of BVDU against tumor cells that have been transduced by the viral TK genes. This finding offers considerable potential in a combined gene therapy/chemotherapy approach for cancer. To the extent that BVDU or its analogues (i.e., BVaraU) are degraded (by thymidine phosphorylase) to (E)-5-(2-bromovinyl)uracil (BVU), they may potentiate the anticancer potency, as well as toxicity, of 5-fluorouracil. This ensues from the direct inactivating effect of BVU on dihydropyrimidine dehydrogenase, the enzyme that initiates the degradative pathway of 5-fluorouracil. The prime determinant in the unique behavior of BVDU is its (E)-5-(2-bromovinyl) substituent. Numerous BVDU analogues have been described that, when equipped with this particular pharmacophore, demonstrate an activity spectrum characteristic of BVDU, including selective anti-VZV activity.
 ...
PMID:(E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU). 1538 33

Xeroderma pigmentosum (XP) is a rare autosomal recessive inherited disorder caused by a defect in the normal repair of DNA of various cutaneous cell types damaged by exposure to ultraviolet radiation. We present our 7-year experience with 36 XP patients who either visited the Department of Dermatology or were seen in the medical camps arranged in remote areas for patients' welfare, from 1995 to 2001. For ease of discussion we classified all cases into the following subgroups on clinical grounds only: mild, those with light brown freckles on the face alone; moderate, those with dark brown freckles with burning on the face, neck, ears, chest, hands and photophobia but without other associated obvious cutaneous and ocular changes; severe, those with extensive dark brown freckles with burning on the exposed parts as well as on the unexposed parts of the body, i.e. the chest, back, abdomen and arms including other associated cutaneous and ocular changes such as ulcers and malignancy. Of 36 patients, three (8.3%) were classified as mild, nine (25%) moderate and 24 (66.7%) severe; there were 18 males and 18 females, age range 2-30 years (mean 8.9 years). Seventeen patients had cutaneous changes: actinic keratosis, keratoacanthoma, fissures and ulcerative nodules on the exposed parts of the body. Four patients had wide ulcers, along with mass formation and severe pigmentation on the face, neck and head. Twenty-nine patients developed ocular symptoms: photophobia, conjunctivitis, corneal keratitis and lid ulcer. One patient had complete loss of vision. Histopathological findings revealed that six patients had squamous cell carcinoma (SCC) on the face, head, ear or lip. More than one sibling (two to four) was affected in four families. The majority of cases (20/36, 55.6%) were from the Brohi tribe (skin type III), while the remaining cases (16/36, 44.4%) were from the Sindhi population (skin type IV). The large number of XP patients seen in those with skin type III (Brohi tribe) compared with skin type IV (Sindhi population) indicates that the skin type and the race has a considerable value in the pathogenesis of XP. Furthermore, 24 of 36 patients were in the severe group and six of these had SCC. Moreover, no neurological abnormalities were observed in our patients. All patients were treated according to disease severity by prescribing oral antibiotics, local steroids, sunscreens and/or chemotherapy followed by irradiation in malignant cases. Two patients died because of extensive SCC.
 ...
PMID:Incidence of xeroderma pigmentosum in Larkana, Pakistan: a 7-year study. 1578 26

Technological advances in the field of gene therapy has prompted more than three hundred phase I and phase II gene-based clinical trials for the treatment of cancer, AIDS, macular degeneration, cardiovascular, and other monogenic diseases. Besides treating diseases, gene transfer technology has been utilized for the development of preventive and therapeutic vaccines for malaria, tuberculosis, hepatitis A, B and C viruses, AIDS, and influenza. The potential therapeutic applications of gene transfer technology are enormous. The cornea is an excellent candidate for gene therapy because of its accessibility and immune-privileged nature. In the last two decades, various viral vectors, such as adeno, adeno-associated, retro, lenti, and herpes simplex, as well as non-viral methods, were examined for introducing DNA into corneal cells in vitro, in vivo and ex vivo. Most of these studies used fluorescent or non-fluorescent marker genes to track the level and duration of transgene expression in corneal cells. However, limited studies were directed to evaluate prospects of gene-based interventions for corneal diseases or disorders such as allograft rejection, laser-induced post-operative haze, herpes simplex keratitis, and wound healing in animal models. We will review the successes and obstacles impeding gene therapy approaches used for delivering genes into the cornea.
 ...
PMID:Gene therapy in the cornea. 1595 19

In order to determine the clinical and laboratory findings of Iranian patients with presumed hyper-immunoglobulin E syndrome (HIES), the medical records of 22 patients from 21 unrelated families, who had been registered in the Iranian Primary Immunodeficiency Registry, were observed. The median age of patients at the time of first symptom and at the time of diagnosis was 1 month and 52.5 months, respectively, with a median diagnosis delay of 70 months. 13 families had consanguineous marriages. IgE level was higher than 2000 IU/ml in all patients, ranging from >2000 to 80,000 IU/ml. The most commonly occurring manifestations were: eczema and dermatitis, pneumonia, upper respiratory tract infections, cutaneous abscesses, diarrhoea, deep abscesses, and otitis media. Other less frequent manifestations were: mucocutaneous candidiasis, sinusitis, cutaneous ulcers, Molluscum contagiosum, herpetic keratitis, onychomycosis, conjunctivitis, septic arthritis, and meningitis. Five patients were complicated by bronchiectasis due to recurrent pneumonia and 5 patients died because of severe infections and malignancy. The HIES is a multisystem disorder that affects especially cutaneous, respiratory, skeletal and the immune system. Although HIES is a rare condition, the recurrent infections should always raise a suspicion, which deserves further evaluation for detecting the syndrome.
 ...
PMID:The clinical and laboratory survey of Iranian patients with hyper-IgE syndrome. 1700 35

Sulfur mustard is an alkylating agent that reacts with ocular, respiratory, cutaneous, and bone marrow tissues, resulting in early and late toxic effects. We compare these effects based on the experience in Iranian veterans exposed to the agent during the Iran-Iraq conflict (1983-88). The first clinical manifestations of sulfur mustard poisoning occurred in the eyes with a sensation of grittiness, lacrimation, photophobia, blepharospasm, and corneal ulceration. Respiratory effects appeared as rhinorhea, laryngitis, tracheobronchitis, and dyspnoea. Skin lesions varied from erythema to bullous necrotization. Initial leukocytosis and lymphopenia returned to normal within four weeks in recovered patients, but marked cytopenia with bone marrow failure occurred in fatal cases. Late toxic effects of sulfur mustard were most commonly found in lungs, skin and eyes. Main respiratory complications were chronic obstructive pulmonary disease, bronchiectasis, asthma, large airway narrowing, and pulmonary fibrosis. Late skin lesions were hyperpigmentation, dry skin, atrophy, and hypopigmentation. Fifteen of the severely intoxicated patients were diagnosed with delayed keratitis, having corneal vascularization, thinning, and epithelial defect. Respiratory complications exacerbated over time, while cutaneous and ocular lesions decreased or remained constant. Both the severity and frequency of bronchiectatic lesions increased during long-term follow-up. The only deteriorating cutaneous complication was dry skin. The maximum incidence of delayed kaeratitis was observed 15 to 20 years after initial exposure. Being suggested as the main cause ofassociated with malignancies and recurrent infections, natural killer cells were significantly lower 16 to 20 years after intoxication.
 ...
PMID:Comparison of early and late toxic effects of sulfur mustard in Iranian veterans. 1704 Feb 11

Wild-type (WT) herpes simplex virus (HSV) causes some pathology, such as ocular keratitis, by increasing infected tissue vascularity, possibly reflecting altered angiogenic factor expression in infected cells. Oncolytic HSVs possess specific mutations enabling selective replication in tumor cells. We investigated whether this ability to enhance infected tissue vascularity is retained in oncolytic HSV, which could be an undesirable effect of oncolytic HSVs that may need to be addressed when treating tumors with oncolytic HSVs. s.c. tumors derived from U87 human glioma cells in athymic mice were treated with oncolytic HSVs G207 or G47Delta in the presence or absence of a recombinant protein composed of the three type-1 repeats (3TSR) of thrombospondin-1 (TSP-1). Real-time reverse transcription-PCR and Western blot of infected cultured cells measured angiogenic factor expression. Microvessel density was assessed using immunofluorescence. G207-treated U87 s.c. tumors had elevated microvessel densities compared with saline- and G47Delta-treated tumors, and G207 treatment caused delayed tumor growth resumption. G207-infected U87 and U373 cells exhibited reduced protein, not mRNA, expression of angiogenesis inhibitors TSP-1 and thrombospondin-2 (TSP-2). 3TSR restored the G207-treated tumor microvessel density to the low level of G47Delta-treated tumors and prevented delayed growth resumption. Oncolytic HSV G207 thus retains the ability of WT HSV to increase infected tissue vascularity. In infected tumors, this increased vascularity is mediated by reduced TSP-1 and TSP-2 levels and causes delayed tumor growth resumption. Incorporating viral mutations, such as those seen in G47Delta or administering thrombospondin-derived peptides, counteracts the angiogenic effect of oncolytic HSV and should be considered when designing oncolytic HSV therapies.
Cancer Res 2007 Jan 15
PMID:Angiogenic response caused by oncolytic herpes simplex virus-induced reduced thrombospondin expression can be prevented by specific viral mutations or by administering a thrombospondin-derived peptide. 1723 49

Whilst the acute effects of sulfur mustard have been relatively well characterised, the chronic effects of short term but significant exposures are still evolving. The approximately 30,000 Iranian victims of CW exposure from the 1980 to 1988 Iran-Iraq war who are currently being followed form a key population who are now 20 years post-exposure. The key chronic findings in this population reflect the common acute effects of sulfur mustard, and are related to the skin, eye and respiratory system. Excluding pruritus, skin changes appear to settle. Eye symptoms are slowly progressive, however a severe, rapid onset form of keratitis is seen to develop in a number of patients after a latent period of 15-20 years. The respiratory tract also shows progressive deterioration, with bronchiolitis obliterans now being considered the main pathological feature of "mustard lung". In addition, there are other potential effects of sulfur mustard exposure which become evident only in the longer term and which are being investigated, including the development of cancer, immunological and neuropsychiatric changes, and reproductive effects. Finally, a chronic effect of sulfur mustard exposure that is now becoming apparent is the wider long-term social and economic effects of these illnesses on individuals and their families.
 ...
PMID:The chronic effects of sulfur mustard exposure. 1948 19

To investigate the clinical and microbiological characteristics of infections caused by Tsukamurella spp., the computerised database of the Bacteriology Laboratory at National Taiwan University Hospital (Taipei, Taiwan) was reviewed retrospectively to identify patients with infections caused by this species during the period January 1997 to December 2008. All of the isolates had been initially misidentified as Rhodococcus spp. Identification of Tsukamurella isolates to species level was carried out by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the heat shock protein gene (hsp65) as well as 16S rRNA gene sequencing. During the study period, a total of eight patients with Tsukamurella infection and two patients with Tsukamurella colonisation were identified. Tsukamurella tyrosinosolvens (n=6) was the most prevalent species, followed by Tsukamurella spumae (n=3) and Tsukamurella pulmonis (n=1). Keratitis was the most common type of infection (n=3), followed by catheter-related bloodstream infection (n=2). One of the patients with Tsukamurella infection died due to bacteraemia; the other seven patients with Tsukamurella infection had favourable outcomes. The three species had different drug susceptibility patterns; T. pulmonis was the most resistant pathogen, with higher minimum inhibitory concentrations of clindamycin (>2 mg/L), erythromycin (2 mg/L) and tetracycline (8 mg/L) than those for the other Tsukamurella spp. In conclusion, strains of Tsukamurella spp., including T. spumae, are uncommon causative agents of ocular infections and bacteraemia in cancer patients. Molecular diagnostic methods are essential to distinguish species in the Tsukamurella genus from species in other phylogenetically related genera such as Rhodococcus.
 ...
PMID:Clinical characteristics of infections caused by Tsukamurella spp. and antimicrobial susceptibilities of the isolates. 2201 86

The widespread use of sulphur mustard (SM) as an incapacitating chemical warfare agent in the past century has proved its long-lasting toxic effects. It may also be used as a chemical terrorist agent. Therefore, all health professionals should have sufficient knowledge and be prepared for any such chemical attack. SM exerts direct toxic effects on the eyes, skin, and respiratory tissue, with subsequent systemic action on the nervous, immunological, haematological, digestive, and reproductive systems. SM is an alkylating agent that affects DNA synthesis, and, thus, delayed complications have been seen since the First World War. Cases of malignancies in the target organs, particularly in haematopoietic, respiratory, and digestive systems, have been reported. Important delayed respiratory complications include chronic bronchitis, bronchiectasis, frequent bronchopneumonia, and pulmonary fibrosis, all of which tend to deteriorate with time. Severe dry skin, delayed keratitis, and reduction of natural killer cells with subsequent increased risk of infections and malignancies are also among the most distressing long-term consequences of SM intoxication. However, despite a lot of research over the past decades on Iranian veterans, there are still major gaps in the SM literature. Immunological and neurological dysfunction, as well as the relationship between SM exposure and mutagenicity, carcinogenicity, and teratogenicity are important fields that require further studies, particularly on Iranian veterans with chronic health effects of SM poisoning. There is also a paucity of information on the medical management of acute and delayed toxic effects of SM poisoning-a subject that greatly challenges health care specialists.
 ...
PMID:Chronic health effects of sulphur mustard exposure with special reference to Iranian veterans. 2246 Feb 16

Recently, there has been an increase in the use of targeted therapies for cancer treatments. Nevertheless, the ocular side-effects of the commonly used targeted agents are generally under-reported and not well studied in the literature. We conducted multiple searches in databases, including Medline, EMBASE, Cochrane Library and conference proceedings, using the following strings: 'name of targeted therapeutic agent (both generic and commercial names)' AND 'eye OR ocular OR vision OR ophthalmological'. Various targeted agents have been found to be associated with ocular side-effects due to their specific targeting of activities in the eye. Imatinib commonly causes periorbital oedema, epiphora and occasionally conjunctival haemorrhage. Cetuximab causes corneal lesions, meibomian gland dysfunction, periorbital and lid dermatitis, blepharitis and conjunctivitis. Erlotinib is related to various ocular toxicities, mainly on the ocular surface, and perifosine has been reported to be associated with severe keratitis. Bevacizumab could potentially disrupt intrinsic ocular circulation and lead to the development of thromboembolic events; there are rare reported cases of optic neuritis or optic neuropathy. Other targeted agents, such as trastuzumab, sunitinib and crizotinib, also have specific ocular toxicities. In conclusion, ocular effects of targeted agents are not uncommon in cancer patients receiving targeted therapy. Ophthalmologists should have high indexes of suspicion to diagnose and treat these complications promptly.
...
PMID:The ophthalmological complications of targeted agents in cancer therapy: what do we need to know as ophthalmologists? 2297 Jul 9


<< Previous 1 2 3 4 5 6 Next >>