Serum complex of trypsin 2 and alpha 1 antitrypsin as diagnostic and prognostic marker of acute pancreatitis: clinical study in consecutive patients.

OBJECTIVE--To estimate the usefulness of serum concentrations of the complex of trypsin 2 and alpha 1 antitrypsin in diagnosing and assessing the severity of acute pancreatitis in comparison with serum C reactive protein, amylase, and trypsinogen 2 concentrations (reference markers). DESIGN--Markers were measured in consecutive patients admitted with acute abdominal pain that was either due to pancreatitis or to other disease unrelated to the pancreas (controls). SETTING--Department of surgery of a teaching hospital in Helsinki. SUBJECTS--110 patients with acute pancreatitis and 66 with acute abdominal diseases of extrapancreatic origin. On the basis of the clinical course, acute pancreatitis was classified as mild (82 patients) or severe (28 patients). MAIN OUTCOME MEASURES--Clinical diagnosis of acute pancreatitis and severity of the disease. RESULTS--At admission all patients with acute pancreatitis had clearly raised concentrations of trypsin 2-alpha 1 antitrypsin complex (32 micrograms/l), whereas only three of the controls had such values. Of the markers studied, trypsin 2-alpha 1 antitrypsin complex had the largest area under the receiver operating curve, both in differentiating acute pancreatitis from extrapancreatic disease and in differentiating mild from severe disease. CONCLUSIONS--Of the markers studied, trypsin 2-alpha 1 antitrypsin complex was the most accurate in differentiating between acute pancreatitis and extrapancreatic disease and in predicting a severe course for acute pancreatitis.     

Enhancement of phagocytosis of parasitized and nonparasitized red cells in acute Plasmodium berghei malaria

The phagocytosis by mouse peritoneal macrophages of parasitized red cells (PRCs) and nonparasitized red cells (nonPRCs) separated from Plasmodium berghei infected blood was studied in vitro. Peritoneal macrophages from acutely infected mice and normal mice were cultured on coverslips. PRCs and nonPRCs were fractionated by Ficoll density gradient centrifugation from Plasmodium berghei infected blood. PRCs were fed in triplicate cultures to normal macrophages in normal serum, normal macrophages in acute serum, acute macrophages in normal serum, and acute macrophages in acute serum. Similarly, nonPRCs were fed to macrophages in the same combinations of normal and acute macrophages and serum. In acute serum, acute macrophages ingest PRCs significantly more readily than normal macrophages (p less than 0.05). Acute macrophages in acute serum ingest PRCs more readily than acute macrophages in normal serum, but the difference does not achieve statistical significance. Acute serum apparently decreases the phagocytosis of PRCs and nonPRCs by normal macrophages, perhaps because of an inhibitory antibody present in acute serum. As with PRCs, in the presence of acute serum, acute macrophages ingest nonPRCs significantly more readily than normal macrophages (p less than 0.05).     

妊娠合并急腹症的超声诊断-附686例临床病例分析

目的:评价超声在诊断妊娠合并急腹症中的临床应用价值。方法:回顾分析686例妊娠合并急腹症患者的临床资料,总结妊娠合并急腹症超声图像特征。结果:超声诊断符合率为:异位妊娠87.2%(184/211),急性阑尾炎84.2%(32/39),卵巢囊肿蒂扭转90.0%(27/30),急性胰腺炎66.7%(6/9),不全流产及难免流产、子宫肌瘤扭转、子宫肌瘤红色变性、胎盘早剥、泌尿系结石、急性胆囊炎和胆结石、急性胃肠炎、急性肠梗阻的诊断率为100%(43/43)。结论:超声可以作为妊娠合并急腹症首选的检查手段,为临床早期诊断及治疗提供可靠依据。     

Sustained Hyperresponsiveness of Dendritic Cells Is Associated with Spontaneous Resolution of Acute Hepatitis C

Some studies have reported that dendritic cells (DCs) may be dysfunctional in a subset of patients with chronic hepatitis C virus (HCV) infection. However, the function of DCs during acute HCV infection and their role in determining infectious outcome remain elusive. Here, we examined the phenotype and function of myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) during acute HCV infection. Three groups of injection drug users (IDUs) at high risk of HCV infection were studied: an uninfected group, a group with acute HCV infection with spontaneous resolution, and a group with acute infection with chronic evolution. We examined the frequency, maturation status, and cytokine production capacity of DCs in response to the Toll-like receptor 4 (TLR4) and TLR7/8 ligands lipopolysaccharide (LPS) and single-stranded RNA (ssRNA), respectively. Several observations could distinguish HCV-negative IDUs and acute HCV resolvers from patients with acute infection with chronic evolution. First, we observed a decrease in the frequency of mature CD86⁺, programmed death-1 receptor ligand-positive (PDL1⁺), and PDL2⁺ pDCs. This phenotype was associated with the increased sensitivity of pDCs from resolvers and HCV-negative IDUs versus the group with acute infection with chronic evolution to ssRNA stimulation in vitro. Second, LPS-stimulated mDCs from resolvers and HCV-negative IDUs produced higher levels of cytokines than mDCs from the group with acute infection with chronic evolution. Third, mDCs from all patients with acute HCV infection, irrespective of their outcomes, produced higher levels of cytokines during the early acute phase in response to ssRNA than mDCs from healthy controls. However, this hyperresponsiveness was sustained only in spontaneous resolvers. Altogether, our results suggest that the immature pDC phenotype and sustained pDC and mDC hyperresponsiveness are associated with spontaneous resolution of acute HCV infection.     

Clinical analysis of the related factors in acute appendicitis

BACKGROUND: In order to determine reliable clues for early diagnosis of acute appendicitis, this study was conducted to examine the related factors in patients with clinically suspected acute appendicitis. METHODS: We retrospectively analyzed 282 patients with the clinical diagnosis of acute appendicitis at China Medical College Hospital in Taiwan from January to December 2000. To study the significant related factors of acute appendicitis, the t-test, chi-square analysis, and multivariate logistic regression analysis were used. RESULTS: There were 153 males (54.3 percent) and 129 females (45.7 percent). The mean age was 30.3+/-17.4 years (range 1 to 81). The diagnostic rate of acute appendicitis was 86.2 percent. If the combination of elevated C-reactive protein, leukocytosis and elevated neutrophil ratio was used, satisfactory specificity and positive predictive value were achieved in diagnosing acute appendicitis. After controlling for the other covariates, the multivariate logistic regression analysis showed that the significant related factors of acute appendicitis were male sex (odds ratio = 3.4; 95 percent confidence interval = 1.6 to 7.3; p <0.01) and elevated neutrophil ratio (odds ratio = 4.6; 95 percent confidence interval = 2.0 to 10.6; p <0.001). CONCLUSIONS: If an elevated neutrophil ratio was observed, the probability of acute appendicitis was increased in patients with clinically suspected acute appendicitis. Thus, neutrophil ratio appears to be a good parameter for diagnosis of acute appendicitis in primary healthcare settings.     

血清GPAA1、SF、OPN与儿童急性淋巴细胞白血病危险度的关系及对血栓发生风险的评估效能研究

摘要 目的：分析血清糖基磷脂酰肌醇锚附着蛋白1（GPAA1）、铁蛋白（SF）、骨桥蛋白（OPN）与儿童急性淋巴细胞白血病危险度的关系及对血栓发生风险的评估效能。方法：选择我院自2017年1月至2022年12月接诊的112例急性淋巴细胞白血病患儿作为观察组，另选112例性别、年龄与观察组相匹配的健康体检儿童作为对照组。检测两组血清GPAA1、SF、OPN表达水平，分析不同危险度的急性淋巴细胞白血病患儿血清GPAA1、SF、OPN表达水平的差异性，观察急性淋巴细胞白血病患儿的血栓发生情况，通过受试者工作特征曲线（ROC）下面积（AUC）评价血清GPAA1、SF、OPN预测急性淋巴细胞白血病患儿发生血栓的效能。结果：观察组血清GPAA1、SF、OPN表达水平均高于对照组（P＜0.05）；在低危、中危和高危的急性淋巴细胞白血病患儿中，血清GPAA1、SF、OPN表达水平有差异（P＜0.05）；经Spearman相关性分析，血清GPAA1、SF、OPN表达水平与儿童急性淋巴细胞白血病危险度呈正相关（P＜0.05）；在112例急性淋巴细胞白血病患儿中，发生血栓12例，占10.71%；经多因素Logistic回归分析，血清GPAA1、SF、OPN均是急性淋巴细胞白血病患儿发生血栓的独立预测因素（P＜0.05）；经ROC曲线分析，血清GPAA1、SF联合OPN预测急性淋巴细胞白血病患儿发生血栓的AUC为0.901。结论：血清GPAA1、SF、OPN与儿童急性淋巴细胞白血病危险度密切相关，联合预测患儿发生血栓的效能较好，对此病的诊治具有重要指导意义。     

Immunological and functional characteristics of the blast cells in acute monoblastic and acute myeloblastic leukemias

The increase in the expression of membrane receptors of monoblast cells to the Fc-fragment of immunoglobulins of classes IgG, IgA, IgM, to the C3-component of complement and FcH receptor in 8 patients with acute monoblastic leukemia and in 3 patients with acute myelomonoblastic leukemia, compared to results obtained for 11 patients with acute myeloblastic leukemia. Leukemic cells in the cases of acute myelomonoblastic and monoblastic leukemia maintained such properties of the phagocytosis (restoring Nitro-blue tetrazolium). Distinctions in degrees of expression of membrane receptors and functional activity of monoblastic and myeloblastic cells may be used as criteria of differential diagnosis of acute monoblastic and acute myeloblastic leukemia.     

Characterization of Microbial Dysbiosis and Metabolomic Changes in Dogs with Acute Diarrhea

Limited information is available regarding the metabolic consequences of intestinal dysbiosis in dogs with acute onset of diarrhea. The aim of this study was to evaluate the fecal microbiome, fecal concentrations of short-chain fatty acids (SCFAs), as well as serum and urine metabolites in healthy dogs (n=13) and dogs with acute diarrhea (n=13). The fecal microbiome, SCFAs, and serum/urine metabolite profiles were characterized by 454-pyrosequencing of the 16S rRNA genes, GC/MS, and untargeted and targeted metabolomics approach using UPLC/MS and HPLC/MS, respectively. Significantly lower bacterial diversity was observed in dogs with acute diarrhea in regards to species richness, chao1, and Shannon index (p=0.0218, 0.0176, and 0.0033; respectively). Dogs with acute diarrhea had significantly different microbial communities compared to healthy dogs (unweighted Unifrac distances, ANOSIM p=0.0040). While Bacteroidetes, Faecalibacterium, and an unclassified genus within Ruminococcaceae were underrepresented, the genus Clostridium was overrepresented in dogs with acute diarrhea. Concentrations of fecal propionic acid were significantly decreased in acute diarrhea (p=0.0033), and were correlated to a decrease in Faecalibacterium (ρ=0.6725, p=0.0332). The predicted functional gene content of the microbiome (PICRUSt) revealed overrepresentations of genes for transposase enzymes as well as methyl accepting chemotaxis proteins in acute diarrhea. Serum concentrations of kynurenic acid and urine concentrations of 2-methyl-1H-indole and 5-Methoxy-1H-indole-3-carbaldehyde were significantly decreased in acute diarrhea (p=0.0048, 0.0185, and 0.0330, respectively). These results demonstrate that the fecal dysbiosis present in acute diarrhea is associated with altered systemic metabolic states.     

A preliminary evaluation of a new enzyme immunoassay to detect Chlamydia pneumoniae-specific antibodies

New enzyme immunoassays (EIAs) for determination of specific IgG, IgA, and IgM antibody titers to Chlamydia pneumoniae were evaluated independently in three research laboratories. Specificity of the EIAs was enhanced by removing LPS from the chlamydial antigen. The performance of these EIAs was evaluated in comparison with the microimmunofluorescence (MIF) test using specimens from: (i) a group of adult patients with community-acquired pneumonia (CAP) previously diagnosed as having an acute chlamydial infection by the complement fixation test or the whole inclusion fluorescence test; (ii) from a group of adult patients with acute respiratory tract infections; and (iii) from a group of young children consecutively presenting with acute respiratory tract infections. The MIF test and the EIAs detected acute infections in paired serum specimens from 12 of 14 patients from the first group. Eleven of these 12 patients were positive in both tests. The MIF test detected seven acute infections in single convalescence serum specimens from eight patients. Two of these were also positive in the EIAs. Paired serum specimens from the second group of adult patients (n=12) were collected during an epidemic of C. pneumoniae. The EIAs detected six acute infections. The MIF test detected two additional patients with acute infections. From the group of young children (n=30), the EIAs detected two patients with acute infections. Our conclusion from this preliminary evaluation is that these EIAs could be useful for laboratory diagnosis of acute C. pneumoniae infections. Comprehensive prospective studies should provide suitable data to calculate the sensitivity, specificity, and predictive values.     

Circulating Levels of Soluble MICB in Infants with Symptomatic Primary Dengue Virus Infections

Dengue is the most prevalent arthropod-borne viral illness in humans. A MHC class I polypeptide-related sequence B (MICB) single nucleotide polymorphism (SNP) was previously associated with symptomatic dengue compared to non-dengue causes of acute febrile illnesses in infants. We measured circulating levels of soluble (s)MICB in the sera of infants with symptomatic primary dengue virus infections. We found that serum levels of sMICB increased between pre-infection and acute illness among infants with symptomatic primary dengue virus infections. The likelihood of being hospitalized with an acute primary DENV infection during infancy also tended to be higher with increasing acute illness sMICB levels. The elevation of sMICB during acute primary DENV infections in infants likely represents an immune evasion strategy and contributes to the severity of the acute illness.     

Fibronectin and factor VIII-related antigen in acute leukaemia

The glycoprotein fibronectin is, as well as by various other cells, also produced in leucocytes and is said to play an important role in malignant transformation of cells. Therefore, the behaviour of plasma fibronectin and of factor VIII R:AG was investigated in acute leukaemia in order to prove their significance as prognostic and therapeutic markers (method: electroimmunoassay). In patients with acute myeloid leukaemia (n = 29) and acute lymphoblastic leukaemia (n = 11) no significant changes in fibronectin concentration could be evaluated. Fibronectin levels declined significantly only during therapy with asparaginase in patients with acute lymphoblastic leukaemia, probably as a result of disturbed synthesis in the liver. Using crossed immunoelectrophoresis against fibronectin antiserum, one normal and one slower migrating antigen (FN:C) could be observed in nearly all plasma samples in patients with acute leukaemia. By means of in vitro tests with highly purified substances and intermediate gel electrophoresis it could be shown that FN:C represents fibronectin which has bound fibrinogen, probably crosslinked by activated factor XIII. Factor VIII R:AG was found to be greatly raised in patients with acute leukaemia--up to 1400% of the normal level. Increased levels correlated well with a worsening of the disease. The protein seems to be suitable for estimating the activity and prognosis of acute leukaemia.     

Acute coronary syndromes following abrupt cessation of oral propranolol therapy.

Abrupt cessation of oral propranolol therapy was followed by 15 acute coronary events in 14 patients with severe angina who had been receiving propranolol in daily doses of 80 to 400 mg for periods of 7 days to 6 years. Propranolol had been stopped 1 to 14 days before each acute event because of angiographic study (seven patients), increasing symptoms (three), acute coronary insufficiency (one), asymptomatic bradycardia (one), elective surgery (one) and unknown reasons (two). Before abrupt cessation of propranolol treatment anginal symptoms had been stable in six instances but had increased in the other nine. Cessation was followed by rapid progression of symptoms prior to 11 of the 15 acute events. There were six acute transmural myocardial infarctions with three deaths, three intramural myocardial infarctions, one with ventricular fibrillation, and six episodes of acute coronary insufficiency, Unstable angina followed nine of the events and responded to propranolol therapy (160 to 320 mg/d) in eight instances. Three other patients underwent aortocoronary bypass surgery; perioperative acute myocardial infarction occurred in two. These data suggest that in a minority of patients abrupt cessation of propranolol may be hazardous, particularly in severe or unstable disease. Cessation or propranolol therapy in such patients should be gradual and closely observed. Recurrent symptoms respond to reinstitution of propranolol therapy.     

High serum levels of soluble interleukin-2 receptor in acute myeloid leukemia: Correlation with poor prognosis and CD4 expression on blast cells

Backgorund: Although increased serum levels of soluble interleukin-2 receptor (sIL-2R) and their clinical importance are well known in mature type lymphoproliferative disorders (LD), little data is available about such information in acute type hematological malignancies. Methods: We examined the serum levels of sIL-2R in 57 adult patients with acute type leukemias: 32 with acute myeloid leukemia (AML), 14 acute lymphoblastic leukemia (ALL) and 11 chronic myelocytic leukemia in blast crisis (CMLBC), and in 29 adult patients with mature type LD, and assessed their cellular and clinical relevance in acute type leukemias. Results: No significant differences were seen in the sIL-2R levels between acute type leukemias and mature type LD. In AML, serum sIL-2R levels were related to the cell surface CD4 expression on blast cells, and patients with higher levels ≧2000U/ml had a poorer prognosis (lower response to chemotherapy and shorter overall survival). Conclusions: These results suggest that serum sIL-2R level elevates in acute type leukemias like mature type LD, and increased sIL-2R levels in adult AML are correlated with certain biological and clinical characteristics.     

Etiology of acute bronchitis in adults

A total of 126 adult patients with acute bronchitis were subjected to microbiological, virological and immunological examination. Influenza and other acute respiratory viral infections were detected in 104 (82.5%) cases of acute bronchitis. The results of microbiological examination and the study of local and systemic immunity showed that in 94.4 +/- 2.6% of the patients the development of acute bronchitis was linked with the appearance of acute pneumococcal infection irrespective of the presence, or absence, of virologically and serologically confirmed acute viral or mycoplasmal infections.     

Antileukemic Efficacy of Continuous vs Discontinuous Dexamethasone in Murine Models of Acute Lymphoblastic Leukemia

Osteonecrosis is one of the most common, serious, toxicities resulting from the treatment of acute lymphoblastic leukemia. In recent years, pediatric acute lymphoblastic leukemia clinical trials have used discontinuous rather than continuous dosing of dexamethasone in an effort to reduce the incidence of osteonecrosis. However, it is not known whether discontinuous dosing would compromise antileukemic efficacy of glucocorticoids. Therefore, we tested the efficacy of discontinuous dexamethasone against continuous dexamethasone in murine models bearing human acute lymphoblastic leukemia xenografts (n = 8 patient samples) or murine BCR-ABL+ acute lymphoblastic leukemia. Plasma dexamethasone concentrations (7.9 to 212 nM) were similar to those achieved in children with acute lymphoblastic leukemia using conventional dosages. The median leukemia-free survival ranged from 16 to 59 days; dexamethasone prolonged survival from a median of 4 to 129 days in all seven dexamethasone-sensitive acute lymphoblastic leukemias. In the majority of cases (7 of 8 xenografts and the murine BCR-ABL model) we demonstrated equal efficacy of the two dexamethasone dosing regimens; whereas for one acute lymphoblastic leukemia sample, the discontinuous regimen yielded inferior antileukemic efficacy (log-rank p = 0.002). Our results support the clinical practice of using discontinuous rather than continuous dexamethasone dosing in patients with acute lymphoblastic leukemia.     

Acute phase cytotoxic T lymphocyte escape is a hallmark of simian immunodeficiency virus infection

Cytotoxic T-lymphocyte (CTL) responses peak coincident with the decline in acute HIV viremia. Despite two reports of CTL-resistant HIV variants emerging during acute infection, the contribution of acute CTL escape to HIV pathogenesis remains unclear. Difficulties inherent in studying acute HIV infection can be overcome by modeling virus-host interactions in SIV-infected rhesus macaques. We sequenced 21 complete simian immunodeficiency virus (SIV)mac239 genomes at four weeks post-infection to determine the extent of acute CTL escape. Here we show that viruses from 19 of 21 macaques escaped from CTLs during acute infection and that these escape-selecting CTLs were responsive to lower concentrations of peptide than other SIV-specific CTLs. Interestingly, CTLs that require low peptide concentrations for stimulation (high 'functional avidity') are particularly effective at controlling other viral infections. Our results suggest that acute viral escape from CTLs is a hallmark of SIV infection and that CTLs with high functional avidity can rapidly select for escape variants.     

Genetic polymorphism in GST, NAT2, and MTRR and susceptibility to childhood acute leukemia

It is known that presence of xenobiotic-metabolizing gene polymorphisms in some cases correlates with hereditary predisposition to the oncological diseases. In the present work the frequencies of xenobiotic-metabolizing gene polymorphisms in 332 children with the diagnosis acute lymphoblastic leukemia (ALL), 71 children with the diagnosis acute myeloblastic leukemia (AML) and 490 healthy donors have been determined using allele-specific hybridization on the biochip. Statistically significant increase in the frequency of GSTT1 "null" genotype (OR = 1.9, p = 4.7E-5) and GSTT1/GSTM1 double "null" genotype (OR = 3.1, p = 2.5E-8) in children with acute leukemia relative to healthy donors group has been revealed. Also 1.8-fold increase in the frequency of NAT2 genotype 341T/T, 481C/C, 590G/G in children with acute leukemia relative to healthy donors group (p = 0.026) has been recognized. Analysis of gene-gene interactions has showed that in patients with acute leukemia genotype NAT2 341T/T, 481C/C, 590G/G in combination with GSTT1 "null" and/or GSTM1 "null" genotype is significantly more frequent than in population control. Besides the reduction of MTRR genotype 66G/G frequency in girls with acute leukemia relative to female healthy donors has been found (OR = 0.50, p = 0.0015). Analysis of gene-gene interactions has shown that the presence of GSTT1 "null" and/or GSTM1 "null" genotype in combination with MTRR genotype 66A/- may consider as risk factor of acute leukemia in girls. Thus, the studied polymorphic variants of genes GSTT1, GSTM1, NAT2 and MTRR can modulate the risk of childhood acute leukemia, residents of European part of Russia.     

Mortality in men admitted to hospital with acute urinary retention: database analysis

Objectives To investigate mortality in men admitted to hospital with acute urinary retention and to report on the effects of comorbidity on mortality.Design Analysis of the hospital episode statistics database linked to the mortality database of the Office for National Statistics.Setting NHS hospital trusts in England, 1998-2005.Participants All men aged over 45 who were admitted to NHS hospitals in England with a first episode of acute urinary retention.Main outcome measures Mortality in the first year after acute urinary retention and standardised mortality ratio against the general population.Results During the study period, 176 046 men aged over 45 were admitted to hospital with a first episode of acute urinary retention. In 100 067 men with spontaneous acute urinary retention, the one year mortality was 4.1% in men aged 45-54 and 32.8% in those aged 85 and over. In 75 979 men with precipitated acute urinary retention, mortality was 9.5% and 45.4%, respectively. In men with spontaneous acute urinary retention aged 75-84, the most prevalent age group, the one year mortality was 12.5% in men without comorbidity and 28.8% in men with comorbidity. The corresponding figures for men with precipitated acute urinary retention were 18.1% and 40.5%. Compared with the general population, the highest relative increase in mortality was in men aged 45-54 (standardised mortality ratio 10.0 for spontaneous and 23.6 for precipitated acute urinary retention) and the lowest for men 85 and over (1.7 and 2.4, respectively).Conclusions Mortality in men admitted to hospital with acute urinary retention is high and increases strongly with age and comorbidity. Patients might benefit from multi-disciplinary care to identify and treat comorbid conditions.     

Significance of Legionella pneumophila in human respiratory pathology

The etiological structure of acute pneumonia and acute respiratory diseases was studied with a view to establishing the proportion of L. pneumophila among other causative agents of such diseases. A total of 299 patients were examined over time. The etiological diagnosis based on the data of serological examination was made in 70.6% of the patients with acute pneumonia and in 65% of the patients with acute respiratory viral infections and influenza. In the etiology of pneumonia, the leading role was found to belong to influenza A (H3N2) and B viruses, as well as to adenovirus, while in the etiology of acute respiratory viral infections and influenza, to influenza B virus, adenovirus and Mycoplasma pneumoniae. The importance of L. pneumophila in the etiology of acute pneumonia and acute respiratory diseases was shown. The proportion of L. pneumophila proved to be, on the average, 9.9% in acute pneumonia and 9.8% in acute respiratory diseases. L. pneumophila occurred most frequently in mixed infections in combination with adenovirus and influenza B virus. Diseases of Legionella etiology were found to have a seasonal character, occurring mostly in winter and spring.     

Differential effects of pressure or volume overload on myocardial MMP levels and inhibitory control

Left ventricular (LV) pressure (PO) or volume (VO) overload is accompanied by myocardial remodeling, but mechanisms that contribute to this progressive remodeling process remain unclear. The matrix metalloproteinases (MMPs) contribute to tissue remodeling in a number of disease states. This study tested the hypothesis that increased MMP expression and activity occur after the induction of an LV overload, which is accompanied by a loss of endogenous MMP inhibitory control. LV MMP zymographic activity and species abundance were measured in dogs under the following conditions: acute PO induced by ascending aortic balloon inflation (6 h, n = 9), prolonged PO by aortic banding (10 days, n = 5), acute VO through mitral regurgitation secondary to chordal rupture (6 h, n = 6), prolonged VO due to mitral regurgitation (14 days, n = 7), and sham controls (n = 11). MMP zymographic activity in the 92-kDa region, indicative of MMP-9 activity, increased over threefold in acute PO and VO and fell to control levels in prolonged PO and VO. The MMP-9 activity-to-abundance ratio increased by over fourfold with acute VO and twofold in acute PO, suggesting a loss of inhibitory control. Endogenous MMP inhibitor content was unchanged with either PO or VO. Interstitial collagenase (MMP-1) content decreased by 50% with acute VO but not with acute PO. Stromelysin (MMP-3) levels increased by 40% with acute VO and increased by 80% with prolonged PO. Although changes in LV myocardial MMP activity and inhibitory control occurred in both acute and prolonged PO and VO states, these changes were not identical. These results suggest that the type of overload stimulus may selectively influence myocardial MMP activity and expression, which in turn would affect the overall LV myocardial remodeling process in LV overload.