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A Das

Publications and source records attributed to A Das.

At least 73 records · Page 4Linked to original sources
PubMed2001

Prevalence and natural history of subclinical hepatic encephalopathy in cirrhosis.

BACKGROUND AND AIMS: The natural history of subclinical hepatic encephalopathy (SHE) is unknown. The present study was conducted to study the prevalence and the natural history of SHE in patients with cirrhosis of the liver. METHODS: One hundred and sixty-five patients with cirrhosis of the liver were studied. A total of nine psychometric tests (trail making and Wechsler adult intelligence scale-performance (WAIS-P) tests) were administered. Subclinical hepatic encephalopathy was present if two or more psychometric tests were abnormal. Seventy-two patients (SHE 40, without SHE 32) also underwent serial psychometric testing on follow-up visits at 6-8 week intervals. RESULTS: Subclinical hepatic encephalopathy was present in 103 (62.4%) patients. The number and figure connection, block design and picture completion tests were the most useful in the detection of SHE. Severity of SHE, as assessed by the number of abnormal tests, was greater in patients with more severe liver disease. During follow up, SHE tended to persist or worsen in patients with poorer liver function. Although other clinical complications were similar in different groups, overt hepatic encephalopathy developed more commonly in those patients who had SHE at entry compared to those who did not (22.6 vs 5.6%, P = 0.044). Among the patients with SHE, the development of overt hepatic encephalopathy was more common in patients with Child's score of > 6 than with Child's score of <or= 6 (40 vs 5%, P = 0.019). CONCLUSIONS: We conclude that SHE is common in cirrhosis. The natural history of SHE is worse in patients with advanced cirrhosis and SHE probably predisposes the cirrhotic patient to overt hepatic encephalopathy.

Adult↗
PubMed2001

Focal atrial tachycardia arising from the tricuspid annulus: electrophysiologic and electrocardiographic characteristics.

INTRODUCTION: Focal right atrial tachycardia (RAT) arising from the crista terminalis, para-Hisian, and coronary sinus os regions are well described. Less information exists regarding RAT arising from the nonseptal region of the tricuspid annulus (TA). METHODS AND RESULTS: From a consecutive series of 64 patients who had undergone successful radiofrequency ablation (RFA) of 67 RATs, the characteristics of 9 (13%) patients (6 men; mean age 50 +/- 20 years) with a TA focus were reviewed. The annular focus was localized to the inferoanterior TA in 7 and the superior TA in 2. Mean tachycardia cycle length was 371 +/- 66 msec. Mean activation time at the site of successful RFA in 9 of 9 patients was -43 +/- 11 msec. At 9.3 +/- 5.6 months of follow-up, 1 of 9 patients had recurrent tachycardia successfully treated with repeat RFA. In 7 of 9 patients with RAT from the inferoanterior TA, the surface ECG P wave morphology was upright in aVL, inverted in III and VI, and either inverted or biphasic with an initial negative deflection from V2 to V6. CONCLUSION: The TA is an important site of origin of RAT. In the present study, the inferoanterior region of the TA was a preferential site of origin with resulting characteristic P wave morphology. Knowledge of this anatomic distribution and P wave morphology allows targeted mapping and may facilitate successful RFA.

Adult↗
PubMed2001

ATP synthase activity in ovine ceroid lipofuscinosis [OCL6].

We measured ATP synthase activities in mitochondria isolated from livers of lambs with ceroid lipofuscinosis (OCL6) and compared them with those from similar isolations from obligate heterozygous and control lambs. Addition of excess Ca2+ to the incubation mixture resulted in an up-regulation of activity in mitochondria from control lambs but down-regulation in those from OCL6 affected lambs. The mean change in activity with Ca2+ for heterozygous animals was midway between those from control and affected groups being significantly different from control but not from affected. The change in ATP synthase activity to added Ca2+ was also measured in isolated mitochondria from affected and control lambs from 3 days to 25 months of age. As above, there was down-regulation to the addition of Ca2+ in affected lambs. There was a fall in percentage change to Ca2+ with age in both affected and control lambs. This was not significantly different in affected lambs indicating it was not associated with the stage of disease. The above in vitro results, if extrapolated to neurons in vivo, imply a potential dysfunction of mitochondria in OCL6 lambs that could lead to calcium mediated neurotoxicity and neuron death due to production of free radicals as implicit in the energy-linked excitotoxic hypothesis.

Animals↗
PubMed2001

Ten years' experience in zygomycosis at a tertiary care centre in India.

OBJECTIVE: To define the spectrum of zygomycosis due to mucorales in an Indian scenario. METHODS: One-hundred and twenty-nine patients with zygomycosis due to mucorales diagnosed at the Postgraduate Institute of Medical Education and Research, Chandigarh, India during 1990-99, were retrospectively analysed regarding the sites of involvement, underlying disease, species of fungi isolated and outcome of therapy. RESULTS: Higher prevalence rate (19.4%) was observed in 1999. Rhino-orbito-cerebral type (44.2%) was the commonest presentation followed by cutaneous (15.5%) and renal (14.0%) involvement. Disseminated zygomycosis was seen in 11.6% patients. Pulmonary and gastrointestinal zygomycosis were diagnosed in 10.1% and 4.7% patients, respectively. Uncontrolled diabetes mellitus (in 50% of cases) was the significant risk factor in rhino-orbito-cerebral type [odds ratio (OR), 9.3; P<or=0.001) and breach of skin (in 40% cases) in cutaneous zygomycosis (OR, 6.9; P<or=0.01). However, a considerable number of 22 (22.9%) patients were apparently healthy hosts in this series. Forty-five patients (34.9%) of this series were diagnosed only at post-mortem. Among 47 patients where culture was attempted, mucorales were isolated from 25 patients with Rhizopus arrhizus (11 patients) and Apophysomyces elegans (eight patients) as the predominant isolates. Adequate therapy could be provided in 33 patients. A combination of aggressive surgical debridement of necrotic tissue and amphotericin-B was found to be the best treatment protocol as 81.3% patients treated with surgical debridement and amphotericin-B were cured, compared with 46.7% patients treated with amphotericin-B alone. CONCLUSION: The study highlights the importance of increased awareness for early diagnosis of zygomycosis and aggressive management. The large number of cases in apparently healthy hosts and increased isolation of A. elegans in the present series are important characteristics of this disease in India and requires further evaluation.

Adolescent↗
PubMed2001

Cervical esophageal perforation during EUS: a national survey.

BACKGROUND: EUS is considered to be as safe a procedure as EGD. However, the longer, rigid tip of the echoendoscopes raises concern about cervical esophageal perforation during intubation. Our aim was to determine the rate of this complication. METHODS: Members of the American Endosonography Club were surveyed by questionnaire to determine the number of EUS examinations performed and the number of cervical esophageal perforations encountered up to June 1999. Each questionnaire was coded to avoid duplicate reporting. RESULTS: Questionnaires were mailed to 203 members; 86 (42.4%) responded. Cervical esophageal perforation occurred in 16 of 43,852 reported upper EUS procedures at a frequency of 0.03%. Fifteen (94%) patients were elderly. A history of difficult intubation with prior endoscopic procedures was present in 7 (44%) patients. Three patients had large cervical osteophytes. In 9 (56%) patients, the procedure was done by an endosonographer with less than 1 year of experience. Two patients required surgery. One patient died as a result of the perforation and the other 13 (81%) patients were managed successfully with conservative treatment. CONCLUSIONS: The incidence of cervical perforation during upper EUS may be higher than during EGD. Advanced patient age, difficult intubation during prior upper endoscopy, operator inexperience, and the presence of large cervical osteophytes may contribute to cervical perforation during upper EUS examination.

Aged↗
PubMed2001

Wire-guided intraductal US: an adjunct to ERCP in the management of bile duct stones.

BACKGROUND: Endoscopic retrograde cholangiography (ERC) may misdiagnose bile duct stones if air bubbles are introduced during contrast injection, and it may also fail to diagnose stones in the presence of bile duct dilation. METHODS: Our aim was to determine whether intraductal US (IDUS) improves the accuracy of cholangiography and whether it is a useful adjunct in the management of bile duct stones. IDUS with a wire-guided US probe was performed after initial ERC in patients in whom bile duct stones were suspected. The diagnostic accuracy of ERC alone was compared with that of ERC plus IDUS. RESULTS: ERC with IDUS was performed in 62 patients who were suspected to have bile duct stones. Both IDUS and ERC were performed by the same endoscopist, and ERC was performed with a C-arm fluoroscope. The presence of bile duct stones and/or sludge were confirmed after sphincterotomy and extraction in 34 patients. Overall, the accuracy of ERC combined with IDUS in the diagnosis of bile duct stone and/or sludge was higher than that of ERC alone (97% vs. 87%, p < 0.05). With dilated bile ducts, the diagnostic accuracy of ERC combined with IDUS was also higher than that of ERC alone (95.5% vs. 72.7%, p < 0.05). Additional diagnostic information provided by IDUS included identification of cystic duct stones in 5 patients, characterization of bile duct strictures in 2 patients, and choledochal varices in 1 patient. Performance of wire-guided IDUS required 5% of the total procedure time. CONCLUSIONS: IDUS improves diagnostic accuracy of ERC and is a useful adjunct to ERC when bile duct stones are suspected.

Aged↗
PubMed2001

High-resolution endoscopic imaging of the GI tract: a comparative study of optical coherence tomography versus high-frequency catheter probe EUS.

BACKGROUND: Both optical coherence tomography (OCT) and catheter probe EUS (CPEUS) are candidates for high-resolution imaging of the GI wall, but their potential roles in this clinical context have not been investigated. METHODS: OCT and CPEUS were used to image normal-appearing portions of the GI tract at the same sites. CPEUS was performed with a 20-MHz or a new 30-MHz catheter probe. RESULTS: Forty-four histologically confirmed normal sites in 27 patients were evaluated. With OCT, mucosa and muscularis mucosa were clearly seen at all sites. Except for stomach, OCT demonstrated the submucosa in all sites. OCT penetration ranged from 0.7 to 0.9 mm. Microscopic structures such as esophageal glands, intestinal villi, colonic crypts, and blood vessels were easily identified. CPEUS penetration ranged from 10 mm to 20 mm, and 5 to 7 distinct layers were discernible. However, both mucosa and submucosa were seen as thin layers without microscopic detail. CONCLUSION: OCT resolution is superior to high-frequency CPEUS, but depth of penetration is limited to mucosa and submucosa. OCT images the major structural components of the mucosa and submucosa whereas CPEUS does not. Potentially, OCT and high-frequency CPEUS may be complementary for clinical imaging.

Endoscopy, Gastrointestinal↗
PubMed2001

Occupational fatigue and preterm premature rupture of membranes. National Institute of Child Health and Human Development Maternal-Fetal Medicine, Units Network.

OBJECTIVE: The aim of this study was to prospectively determine the relationship between occupational fatigue and spontaneous preterm delivery segregated into the etiologically distinct categories of spontaneous preterm labor, preterm premature rupture of membranes, and indicated preterm delivery. STUDY DESIGN: A total of 2929 women with singleton pregnancies at 22 to 24 weeks' gestation were enrolled in a multicenter (10 sites) Preterm Prediction Study. Patients reported the number of hours worked per week and answered specific questions designed to determine the following 5 sources of occupational fatigue described by Mamelle et al: posture, work with industrial machines, physical exertion, mental stress, and environmental stress. Fatigue was quantified (0-5 index) according to the number of these sources positively reported. Simple and Mantel-Haenszel chi2 tests were used to test the univariate association and hypothesis of a linear trend between sources of occupational fatigue and spontaneous preterm delivery. Covariables were considered by multivariate logistic regression analysis. Women who did not work outside the home were considered separately from those who worked but did not report any sources of occupational fatigue. RESULTS: Each source of occupational fatigue was independently associated with a significantly increased risk of preterm premature rupture of membranes among nulliparous women but not among multiparous women. The risk of preterm premature rupture of membranes increased (P = .002) with an increasing number of sources of occupational fatigue-not working outside the home, 2.1%; working but not reporting fatigue, 3.7%; working with 1 source of fatigue, 3.2%; working with 2 sources of fatigue, 5.2%; working with 3 sources of fatigue, 5.1%; and working with 4 or 5 sources of fatigue, 7.4%. There was also a significant relationship (P = .01) between preterm premature rupture of membranes and an increasing number of hours worked per week among nulliparous women. Neither spontaneous preterm labor nor indicated preterm delivery was significantly associated with occupational fatigue among either nulliparous or multiparous women. CONCLUSION: The occupational fatigue index of Mamelle et al discriminated a group of nulliparous women at increased risk for preterm premature rupture of membranes. The relationship between preterm premature rupture of membranes and occupational fatigue or hours worked may provide guidelines according to which nulliparous women and their employers can be advised.

Adolescent↗
PubMed2001

The Preterm Prediction Study: toward a multiple-marker test for spontaneous preterm birth.

OBJECTIVE: The Preterm Prediction Study evaluated 28 potential biologic markers for spontaneous preterm birth in asymptomatic women at 23 to 24 weeks gestational age. This analysis compares those markers individually and in combination for an association with spontaneous preterm birth at <32 and <35 weeks gestational age. STUDY DESIGN: With the use of a nested case-control design from an original cohort study of 2929 women, results of tests from 50 women with a spontaneous preterm birth at <32 weeks and 127 women with a spontaneous preterm birth at <35 weeks were compared with results from matched-term control subjects. RESULTS: In the univariate analysis, the most potent markers that are associated with spontaneous preterm birth at <32 weeks by odds ratio were a positive cervical-vaginal fetal fibronectin test (odds ratio, 32.7) and <10th percentile cervical length (odds ratio, 5.8), and in serum, >90th percentiles of alpha-fetoprotein (odds ratio, 8.3) and alkaline phosphatase (odds ratio, 6.8), and >75th percentile of granulocyte colony-stimulating factor (odds ratio, 5.5). Results for spontaneous preterm birth at <35 weeks were generally similar but not as strong. Univariate and multivariate logistic regression analyses demonstrated little interaction among the tests in their association with spontaneous preterm birth. Combinations of the 5 markers were evaluated for their association with <32 weeks spontaneous preterm birth. Ninety-three percent of case patients had at least 1 positive test result versus 34% of control subjects (odds ratio, 24.0; 95% CI, 6.4-93.4). Among the case patients, 59% had >or=2 positive test results versus 2.4% of control subjects (odds ratio, 56.5; 95% CI, 7.1-451.7). If a cutoff of 3 positive test results was used, 20% of case patients and none of the control subjects had positive test results (P < .002). With the use of only the 3 serum tests (alkaline phosphatase, alpha-fetoprotein, and granulocyte colony-stimulating factor), any positive test identified 81% of cases versus 22% of control subjects (odds ratio, 14.7; 95% CI, 5.0-42.7). For spontaneous preterm birth at <35 weeks gestation, any 2 positive tests identified 43% of cases and 6% of control subjects (odds ratio, 11.2; 95% CI, 4.8-26.2). CONCLUSION: Overlap among the strongest biologic markers for spontaneous preterm birth is small. This suggests that the use of tests such as maternal serum alpha-fetoprotein, alkaline phosphatase, and granulocyte colony-stimulating factor as a group or adding their results to fetal fibronectin test and cervical length test results may enhance our ability to predict spontaneous preterm birth and that the development of a multiple-marker test for spontaneous preterm birth is feasible.

Alkaline Phosphatase↗
PubMed2001

Benchmarking applications: linking state strategic planning, quality improvement, and consumer reporting.

This article demonstrates the value of using benchmark patient satisfaction data for Medicaid program quality improvement. The authors compare surveys of Maryland Medicaid and federal employees in Maryland, utilizing the latter as an external benchmark. Unadjusted and adjusted analyses found a significantly lower percentage of Medicaid than federal respondents rated telephone access excellent, very good, or good, whereas more Medicaid respondents rated advice on prevention and choice of primary care doctor highly. Patient satisfaction external benchmark data provide managed care organizations (MCOs) and state policy makers with goals to improve quality and standards to measure care objectively in vulnerable populations.

Benchmarking↗
PubMed2001

Functional analysis of the Agrobacterium tumefaciens T-DNA transport pore protein VirB8.

The VirB8 protein of Agrobacterium tumefaciens is essential for DNA transfer to plants. VirB8, a 237-residue polypeptide, is an integral membrane protein with a short N-terminal cytoplasmic domain. It interacts with two transport pore proteins, VirB9 and VirB10, in addition to itself. To study the role of these interactions in DNA transfer and to identify essential amino acids of VirB8, we introduced random mutations in virB8 by the mutagenic PCR method. The putative mutants were tested for VirB8 function by the ability to complement a virB8 deletion mutant in tumor formation assays. After multiple rounds of screening 13 mutants that failed to complement the virB8 deletion mutation were identified. Analysis of the mutant strains by DNA sequence analysis, Western blot assays, and reconstruction of new point mutations led to the identification of five amino acid residues that are essential for VirB8 function. The substitution of glycine-78 to serine, serine-87 to leucine, alanine-100 to valine, arginine-107 to proline or alanine, and threonine-192 to methionine led to the loss of VirB8 activity. When introduced into the wild-type strain, virB8(S87L) partially suppressed the tumor forming ability of the wild-type protein. Analysis of protein-protein interaction by the yeast two-hybrid assay indicated that VirB8(R107P) is defective in interactions with both VirB9 and VirB10. A second mutant VirB8(S87L) is defective in interaction with VirB9.

Agrobacterium tumefaciens↗
PubMed2001

Five-gene cluster in Clostridium thermoaceticum consisting of two divergent operons encoding rubredoxin oxidoreductase- rubredoxin and rubrerythrin-type A flavoprotein- high-molecular-weight rubredoxin.

A five-gene cluster encoding four nonheme iron proteins and a flavoprotein from the thermophilic anaerobic bacterium Clostridium thermoaceticum (Moorella thermoacetica) was cloned and sequenced. Based on analysis of deduced amino acid sequences, the genes were identified as rub (rubredoxin), rbo (rubredoxin oxidoreductase), rbr (rubrerythrin), fprA (type A flavoprotein), and a gene referred to as hrb (high-molecular-weight rubredoxin). Northern blot analysis demonstrated that the five-gene cluster is organized as two subclusters, consisting of two divergently transcribed operons, rbr-fprA-hrb and rbo-rub. The rbr, fprA, and rub genes were expressed in Escherichia coli, and their encoded recombinant proteins were purified. The molecular masses, UV-visible absorption spectra, and cofactor contents of the recombinant rubrerythrin, rubredoxin, and type A flavoprotein were similar to those of respective homologs from other microorganisms. Antibodies raised against Desulfovibrio vulgaris Rbr reacted with both native and recombinant Rbr from C. thermoaceticum, indicating that this protein was expressed in the native organism. Since Rbr and Rbo have been recently implicated in oxidative stress protection in several anaerobic bacteria and archaea, we suggest a similar function of these proteins in oxygen tolerance of C. thermoaceticum.

Amino Acid Sequence↗
PubMed2001

Prevalence and predictors of immunization among inner-city infants: a birth cohort study.

CONTEXT: Although the proportion of US children who are appropriately immunized increased dramatically in the past decade, rates remain suboptimal among low-income, inner-city youth. Timely initiation of immunization is an important predictor of immunization status later in childhood; however, prospective studies identifying predictors of initiation are lacking. OBJECTIVES: The objectives of this study were to: 1) describe immunization patterns in a cohort of infants born to predominantly low-income, inner-city mothers; 2) identify determinants, as measured at birth, of immunization status at 3 and 7 months of age; and 3) identify determinants of continuation of immunization among those who initiate immunization by 3 months of age. DESIGN: Prospective, birth cohort study. METHODS: Maternal/infant dyads were systematically selected from 3 District of Columbia hospitals between August 1995 and September 1996. Three hundred sixty-nine mothers were interviewed shortly after delivery, at 3 to 7 months postpartum, and at 7 to 12 months postpartum. Medical records were reviewed at all reported sites of care for 324 (88%) infants. Vaccinations assessed included diphtheria, tetanus, and pertussis; polio; and Haemophilus influenzae type B. Multivariate logistic regression analyses were used to determine factors associated with immunization status of infants at 3 and 7 months of age. RESULTS: At 3 months of age, 75% of infants were up-to-date (UTD) versus only 41% at 7 months. In adjusted analyses, baseline factors associated with being UTD at 3 months included enrollment in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) during pregnancy, intention to breastfeed, and presence of the infant's grandmother in the household. Infants were less likely to be UTD if their mothers perceived higher barriers to immunization. Baseline factors associated with being UTD at 7 months included lower birth order and maternal employment. Among the subset of infants who were UTD at 3 months, only 53% remained UTD at 7 months. Factors measured at the first follow-up interview that were associated with continuation of immunization at 7 months included maternal employment and lower perceived barriers. CONCLUSIONS: Immunization rates during the first 7 months of life were low in this inner-city population. Factors associated with immunization status that are potentially amenable to change included perceived barriers to immunization and enrollment in WIC during pregnancy.

Adult↗
PubMed2001

Effects of early erythropoietin therapy on the transfusion requirements of preterm infants below 1250 grams birth weight: a multicenter, randomized, controlled trial.

OBJECTIVES: Infants of </=1250 g birth weight receive multiple erythrocyte transfusions during their hospitalization. We hypothesized that early erythropoietin (Epo) and iron therapy would 1) decrease the number of transfusions received (infants 401-1000 g birth weight; trial 1) and 2) decrease the percentage of infants who received any transfusions (1001-1250 g birth weight; trial 2). METHODS: A total of 172 infants in trial 1 and 118 infants in trial 2 were randomized to treatment (Epo, 400 U/kg 3 times weekly) or placebo/control. Therapy was initiated by 4 days after birth and continued through the 35th postmenstrual week. All infants received supplemental parenteral and enteral iron. Complete blood and reticulocyte counts were measured weekly, and ferritin concentrations were measured monthly. Transfusions were administered according to protocol. Phlebotomy losses and transfusion data were recorded. RESULTS: Treated and placebo/control infants in trial 1 received a similar number of transfusions (4.3 +/- 3.6 vs 5.2 +/- 4.2, respectively). A similar percentage of treated and control infants in trial 2 received at least 1 transfusion (37% vs 46%). Reticulocyte counts were higher in treated infants during each week of the study in both trials. Hematocrits were higher among treated infants from week 2 on in both trials. Ferritin concentrations were higher in placebo/controls than in treated infants at weeks 4 and 8 in trial 1 and at week 4 in trial 2. No adverse effects of Epo or supplemental iron occurred. CONCLUSION: The combination of early Epo and iron as administered in this study stimulated erythropoiesis in infants who were </=1250 g at birth. However, the lack of impact on transfusion requirements fails to support routine use of early Epo.neonate, intravenous iron, donor exposure.

Anemia, Neonatal↗
PubMed2001

The brain decade in debate: VI. Sensory and motor maps: dynamics and plasticity.

This article is an edited transcription of a virtual symposium promoted by the Brazilian Society of Neuroscience and Behavior (SBNeC). Although the dynamics of sensory and motor representations have been one of the most studied features of the central nervous system, the actual mechanisms of brain plasticity that underlie the dynamic nature of sensory and motor maps are not entirely unraveled. Our discussion began with the notion that the processing of sensory information depends on many different cortical areas. Some of them are arranged topographically and others have non-topographic (analytical) properties. Besides a sensory component, every cortical area has an efferent output that can be mapped and can influence motor behavior. Although new behaviors might be related to modifications of the sensory or motor representations in a given cortical area, they can also be the result of the acquired ability to make new associations between specific sensory cues and certain movements, a type of learning known as conditioning motor learning. Many types of learning are directly related to the emotional or cognitive context in which a new behavior is acquired. This has been demonstrated by paradigms in which the receptive field properties of cortical neurons are modified when an animal is engaged in a given discrimination task or when a triggering feature is paired with an aversive stimulus. The role of the cholinergic input from the nucleus basalis to the neocortex was also highlighted as one important component of the circuits responsible for the context-dependent changes that can be induced in cortical maps.

Animals↗
PubMed2001

The balance between proteinases and inhibitors in a murine model of proliferative retinopathy.

PURPOSE: To examine the expression of matrix metalloproteinases (MMPs) and their inhibitors during the development of retinal neovascularization (NV) in a mouse model. METHODS: A well-characterized murine model of retinal NV was used to study the expression of specific MMPs (MMP-2, MMP-9, and MT1-MMP) and tissue inhibitor of metalloproteinases (TIMPs types 1, 2, and 3). NV of the retina was induced in mice by exposure to 75% O(2) from postnatal day (P)7 to P12, followed by return to room air from P12 to P17. Expression of MMP mRNA was analyzed by reverse transcription-polymerase chain reaction (RT-PCR). In addition, retinal tissue removed from control (without NV) and experimental animals (with NV) was analyzed for the expression of TIMP-1, TIMP-2, and TIMP-3 mRNA and protein using RT-PCR and Western blot analysis. RESULTS: During the angiogenic period from P13 to P17, MMP-2 and -9, and MT1-MMP message expression increased in experimental retinas compared with control samples. The TIMP-2 message and protein levels increased steadily in the retina of control animals until P17. This was in contrast to that seen in the retinas of the experimental animals in which TIMP-2 message and protein remained low and significantly less than in control samples. There were no significant changes in TIMP-3 message levels in retinal tissues, and TIMP-1 message and protein were undetectable. CONCLUSIONS: Correlation was made at the mRNA and protein levels of TIMP expression compared with that of MMPs in a murine model of retinal NV, which suggests a temporal role for MMP-2 and -9, MT1-MMP, and TIMP-2 in new vessel formation in response to hypoxic stimulation.

Animals↗