Activation of matrix metalloproteinase dilates and decreases cardiac tensile strength.

Previous studies demonstrated that transition from compensatory pressure overload hypertrophy to decompensatory volume overload heart failure is associated with decreased cardiac tensile strength and activation of matrix metalloproteinase (MMP) in spontaneously hypertensive rat (SHR). To test the hypothesis that in the absence of nitric oxide activation of MMP during cardiac failure causes disruption in the organization of extracellular matrix (ECM) and leads to decrease systolic and diastolic cardiac tensile strength, we employed SHR of 24--32 weeks, which demonstrates significant cardiac hypertrophy and fibrosis. The normotensive Wistar rats (NWR) were used as control. To determine whether cardiac hypertrophy is associated with increased elastinolytic matrix metalloproteinase-2 (MMP-2) activity; quantitative elastin-zymography was performed on cardiac tissue homogenates. The MMP-2 activity was normalized by the levels of actin. The MMP-2/actin ratio was 2.0+/-0.5 in left ventricle (LV) and 1.5+/-0.25 in right ventricle (RV) of SHR(32wks); and 0.5+/-0.25 in LV and 0.25+/-0.12 in RV of NWR(32wks) (P<0.02 when SHR compared with NWR). To measure passive diastolic cardiac function, rings from LV as well as RV through transmyocardial wall from male SHR and NWR of 6--8 weeks and 24--36 weeks were prepared. The LV wall thickness from endocardium to epicardium was 3.75+/-0.25 mm in SHR(32wks) as compared to 2.25+/-0.50 mm in NWR(32wks) (P<0.01). The ring was placed in tissue myobath and length--tension relationships were assessed. The pressure--length relationship was shifted to left in SHR as compared to NWR. The amounts of cardiac elastin and collagen were determined spectrophotometrically by measuring desmosine--isodesmosine and hydroxyproline contents, respectively. A negative correlation between elastic tensile strength and elastin/collagen ratio was elucidated. To create situation analogous to heart failure and MMP activation, we treated cardiac rings with active MMP-2 and length--tension relation was measured. The relationship was shifted to right in both SHR and NWR when compared to their respective untreated groups. The results suggested that activation of MMP led to decreased cardiac tissue tensile strength and may cause systolic and diastolic dysfunction.

Open-label phase II trial of amprenavir, abacavir, and fixed-dose zidovudine/lamivudine in newly and chronically HIV-1--infected patients.

A Phase II clinical trial was designed to evaluate the efficacy and tolerability of twice-daily abacavir, amprenavir, and zidovudine (ZDV)/lamivudine (3TC) in HIV-1-infected study subjects naive to protease inhibitors and 3TC. Plasma and cerebrospinal fluid (CSF) HIV-1 RNA levels and T-cell subsets were measured. In all, 27 newly diagnosed and 12 chronically HIV-1-infected study subjects are included in the analysis. Week 48 plasma HIV-1 RNA levels were <500 copies/ml in 100% of study subjects, and <50 copies/ml in 80% of chronically infected and 100% of newly infected study subjects. The mean change in CD4 was (+)150 cells/microl (newly infected, p <.001), and (+)155 cells/microl (chronically infected, p <.001). At Week 48, evidence of cellular activation persisted in both cohorts. A twice-daily regimen of amprenavir, abacavir, and ZDV/3TC affords potent viral suppression and significant increases in total CD4(+) cells in HIV-1--infected study subjects. Patient intolerance may limit the efficacy of this combination.

Virologic and immunologic effect of antiretroviral therapy on HIV-1 in gut-associated lymphoid tissue.

OBJECTIVES: We evaluated virologic and immunologic responses to antiretroviral therapy in gut-associated lymphoid tissue (GALT) compared with those found in peripheral blood. METHODS: Eight HIV-1-infected individuals were treated with three reverse transcriptase inhibitors and one protease inhibitor. Endoscopic biopsies were performed at baseline, and at months 1, 2, and 6. We measured the level of cell-associated multiply spliced and unspliced HIV-1 mRNA in GALT and in peripheral blood mononuclear cells. Immunologic responses were assessed by flow cytometry. RESULTS: Levels of multiply spliced HIV-1 mRNA declined in parallel fashion both in peripheral blood and GALT. After 6 months of therapy, unspliced HIV-1 mRNA in the GALT was below assay detection although it persisted in peripheral blood mononuclear cells in 4 study subjects. Although the percentage of CD4+ lymphocytes increased significantly in peripheral blood, only modest increases occurred in GALT. The percentage of activated CD8+ T cells decreased significantly in peripheral blood whereas only modest reductions occurred in GALT. CONCLUSIONS: Antiretroviral therapy effectively suppressed HIV-1 replication in GALT. The percentage of CD4+ T cells in peripheral blood uniformly increased in all study subjects, whereas it was more variable in the GALT.

Homocyst(e)ine impairs endocardial endothelial function.

Homocyst(e)ine injured vascular endothelium and modulated endothelial-dependent vascular function. Endothelium plays an analogous role in both the vessel and the endocardium. Therefore, we hypothesized that homocyst(e)ine modulated endocardial endothelium (EE) dependent cardiac function. The ex vivo cardiac rings from normal male Wistar-Kyoto rats were prepared. The contractile responses of left and right ventricular rings were measured in an isometric myobath, using different concentrations of CaCl2. The response was higher in the left ventricle than right ventricle and was elevated in endocardium without endothelium. The half effective concentration (EC50) and maximum tension generated by homocyst(e)ine were 10(6) and 5-fold lower than endothelin (ET) and angiotensin II (AII), respectively. However, in endothelial-denuded endocardium, homocyst(e)ine response was significantly increased (p<0.005, compared with intact endothelium) and equal to the response to ET and AII. To determine the physiological significance of ET, AII, homocyst(e)ine, and endothelial nitric oxide in EE function, cardiac rings were pretreated with AII (10(-10) M) or ET (10(-13) M) and then treated with homocyst(e)ine (10(-8) M). Results suggested that at these concentrations AII, ET, or homocyst(e)ine alone had no effect on cardiac contraction. However, in the presence of 10(-10) M AII or 10(-13) M ET, the cardiac contraction to homocyst(e)ine (10(-8) M) was significantly enhanced (p<0.01, compared with without pretreatment) and further increased in the endocardium without endothelium. The pretreatment of cardiac ring with the inhibitor of nitric oxide, Nomega-nitro-L-arginine methyl ester (L-NAME), increased contractile response to homocyst(e)ine. These results suggested that homocyst(e)ine impaired EE-dependent cardiac function and acted synergistically with AII and ET in enhancing the cardiac contraction.

Stretch-induced membrane type matrix metalloproteinase and tissue plasminogen activator in cardiac fibroblast cells.

In the normal heart, cardiomyocytes are surrounded by extracellular matrix (ECM) and latent matrix metalloproteinases (MMPs), which are produced primarily by cardiac fibroblasts. An activator of latent MMPs might be induced by ischemic conditions or pressure-induced stretching. To test the hypothesis that an activator of latent MMP is induced in the ischemic heart during transformation of a compensatory hypertrophic response to a decompensatory failing response in cardiac fibroblast cells, we stretched the human cardiac fibroblasts at 25 cycles/min in serum-free or 5% serum culture condition. The membrane type (MT)-MMP activity in stretched cells was measured by zymography and immuno-blot analyses using MT-MMP-2 antibody. The MT-MMP activity was further characterized by transverse-urea gradient (TUG)-zymography. The results suggested that stretch induced a membrane MMP in the fibroblasts that was similar to the MT-MMP induced in ischemic heart. Furthermore, we observed that membrane MMP has distinct mobility in TUG-zymography. To localize the MT-MMP and tissue plasminogen activator (tPA) of latent MMPs, the membrane and cytosol were separated by a method employing a detergent and sedimentation. The MT-MMP and tPA activities of cytosol and membrane fractions were measured by gelatin- and plasminogen-zymography, respectively. Differential-display mRNA analysis was performed on control and stretched cells. In situ immuno-labelling was performed to localize the MT-MMP. The results indicate that induction of MT-MMP occurred in the membrane fractions. The secretion of tPA was elevated in the stretched cells. The MT-MMP activity was inhibited by prior incubation with an antibody generated to membrane MMP. The tPA activity was inhibited by using tPA antibody. These results suggest that, under stretched conditions, neutral transmembrane matrix proteinases are induced in the cardiac fibroblasts. This may lead to activation of adverse ECM remodeling, cardiac dilatation, and failure.

Reduction-oxidation (Redox) and vascular tissue level of homocyst(e)ine in human coronary atherosclerotic lesions and role in extracellular matrix remodeling and vascular tone.

Hyperhomocyst(e)inemia in patients with coronary and peripheral arterial occlusion has been demonstrated by others. Redox-state of homocyst(e)ine causes dysfunction of endothelial cells and promote growth of vascular smooth muscle cells. The role of tissue, protein bound and unbound, oxidative mixed disulfides in the development of fibrous plaque in atherosclerotic lesion is not known. Redox-state around the fibroblasts and vascular smooth muscle cells modulates the expression of extracellular matrix (ECM) components (Tyagi et al. 1996, J Cell Biochem, 61: 139-151). To determine the role of tissue homocystine in fibrotic atherosclerotic plaque development, coronary arteries were isolated from ischemic explanted hearts (n = 10). Apparently normal vascular tissue was obtained from idiopathic cardiomyopathic explanted hearts (n = 10). Tissue extract were prepared from atherosclerotic lesions and from normal arteries devoid of adventitia. Interaction of homocystine with Ellman's reagent (5, 5'-dithio-bis-2-nitro benzoic acid) catalyzed by limiting amount of reducing agent (catalyst) generated change in optical density (OD) at 412 nm in dose dependent fashion. We have generated a standard curve between change at 412 nm and amount of homocystine. The change in OD at 412 nm with increasing amount (0-25 microg) of homocystine demonstrated linearity. The protein-bound oxidized disulfides were precipitated by trichloroacetic acid (TCA) and free-oxidative disulfides in the supernatant were collected. The pathophysiological amount of protein-bound disulfide in atherosclerotic tissue (1.0 +/- 0.2 microg/mg total protein) was 10 times that in normal tissue (0.1 +/- 0.01 microg/mg, p < 0.001). The amount of free oxidative disulfide in atherosclerotic tissue (1.5 +/- 0.3 microg/mg) was 15 times that in normal tissue (0.12 +/- 0.02 microg/mg, p < 0.001). To determine the role of homocystine in ECM expression, ECM collagenase activity in the presence and absence of homocystine was measured by zymography. The effect of homocysteine on collagenase activity was biphasic, increased at < [0.01 mM] and inhibited at > [0.1 mM]. To determine whether homocystine regulates vascular tone, isometric measurements were carried out using normal coronary rings. Results suggested that homocystine induced endothelial-modulated vasoconstriction in coronary vessels. Tissue oxidative disulfides and the homocystine may contribute to the development of fibrotic atherosclerotic lesions and vascular dysfunction.

An approach to teaching ethical, legal, and psychosocial aspects of gynecologic oncology in a residency program.

An approach to teaching ethical, legal, and psychosocial issues in gynecologic oncology has been integrated into an obstetrics and gynecology residency program. Team-teaching is used, involving gynecologic oncology faculty members and a medical ethicist with experience teaching in the clinical setting of obstetrics and gynecology. The teaching takes place as part of ongoing teaching rounds in the division of gynecologic oncology. Articles from clinical journals are used to inform and stimulate discussion of clinical ethical, legal, and psychosocial issues. Integrating the teaching of ethical and legal aspects of gynecologic oncology into residency education is challenging, given the competing demands on the residents' time and the need for teaching to be clinically relevant. The program described in this article illustrates that such teaching can be carried out in a manner that covers main issues and has practical value for residents.

Effectiveness of paclitaxel in treating papillary serous carcinoma of the peritoneum in an adolescent.

A 15-year-old girl with papillary serous carcinoma of the peritoneum was seen with abdominal distention, ascites, and elevated CA 125 tumor marker. After other therapy failed, she achieved complete and continuing remission with paclitaxel.

The use of hetastarch as adjunct therapy in 26 dogs with hypoalbuminemia: a phase two clinical trial.

The purpose of this study was to evaluate the safety and efficacy of the synthetic colloid hetastarch in dogs with hypoalbuminemia. Individual doses of hetastarch ranged from 9 to 27 mL/kg, and multiple doses were used frequently. Total doses ranged from 9 to 59 mL/kg. Colloid oncotic pressure was measured in 13 dogs before and after treatment. Mean colloid oncotic pressure +/- SD was 9.32 +/- 2.35 mm Hg before treatment and 16.41 +/- 1.61 mm Hg in 8 healthy pet dogs used as controls. The difference in these values was significant (P < .001). There was a significant increase in mean colloid oncotic pressure after the first dose of hetastarch, but there was no relationship between the dose of hetastarch and the magnitude of increase in colloid oncotic pressure. Peripheral edema or body cavity transudates resolved or decreased in 83% of the dogs despite concurrent use of crystalloid fluid therapy. There was also no relationship between the dose of hetastarch and resolution of edema. Worsening of the results from coagulograms occurred in 5 of 18 dogs, and included increased prothrombin time (n = 1), increased partial thromboplastin time (n = 5), and decreased platelet count (n = 3). Bleeding that occurred in 3 dogs could not be directly attributed to the hetastarch. There was no relationship between the dose of hetastarch and worsening of the values in the coagulograms.

Evaluation of a urine cortisol:creatinine ratio as a screening test for hyperadrenocorticism in dogs.

The authors collected urine specimens in 31 normal dogs, 25 dogs with hyperadrenocorticism, 21 dogs in which hyperadrenocorticism was suspected but was not present, and 28 dogs with a variety of severe, nonadrenal diseases. Cortisol and creatinine were measured in unextracted urine by radioimmunoassay and spectrophotometry, respectively, and the cortisol:creatinine ratio was calculated for each specimen. The mean +/- SD urine cortisol:creatinine concentration ratio in the dogs with hyperadrenocorticism (103.1 +/- 100.7) was significantly (P < 0.001) higher than that in the normal dogs (13.1 +/- 7.0). The mean urine cortisol:creatinine ratio in dogs initially suspected of having hyperadrenocorticism (16.3 +/- 7.0) was significantly (P < 0.001) lower than the ratio in dogs with hyperadrenocorticism, but was not significantly different than that in the normal dogs. The mean urinary cortisol:creatinine ratio in the dogs with nonadrenal disease (82.8 +/- 97.7) was significantly (P < 0.001) higher than that in both the normal dogs and dogs in which hyperadrenocorticism was initially suspected, but was not different than the ratio in the dogs with hyperadrenocorticism. The sensitivity of the urine cortisol:creatinine ratio as a diagnostic test for hyperadrenocorticism was 0.92. The specificity was high in the normal dogs (0.97) and the dogs initially suspected of having hyperadrenocorticism (0.95), with < or = 5% having false-positive results. However, the specificity was very low (0.21) in the dogs with moderate to severe nonadrenal disease, with 79% having false-positive results. Similarly, both positive and negative predictive values and diagnostic efficiency were high in the normal dogs and dogs suspected of having hyperadrenocorticism but were low in the dogs with nonadrenal illness.(ABSTRACT TRUNCATED AT 250 WORDS)

The use of hetastarch for plasma expansion.

The use of colloids in hypo-oncotic individuals to increase plasma volume has been shown to have distinct and consistent advantages compared with the use of crystalloid fluids. Colloids increase plasma colloid oncotic pressure, whereas crystalloids decrease it, an effect that can be extremely detrimental in individuals with low basal plasma colloid oncotic pressure. Increasing plasma volume in hypo-oncotic individuals without inducing large increases in interstitial water content is difficult when crystalloid fluids are used. However, colloids have much better plasma volume expansion ability without the induction of concurrent increases in interstitial water content, even in hypooncotic individuals. Review of the literature indicates that hetastarch is an extremely safe colloid for acute and long-term use in humans and dogs. Its excellent safety record probably is attributable to its structural analogy to the natural compound glycogen. The lack of availability of a substance analogous to human 5% serum albumin and the scarcity of plasma in veterinary medicine leaves hetastarch as the safest option of available colloids. Its ability to increase plasma volume and colloid oncotic pressure is equal to or better than dextran 70 and 5% albumin and is clearly better than plasma or whole blood. Increases in plasma volume and colloid oncotic pressure usually last approximately 48 hours after a single injection, but the duration of increases significantly after multiple infusions. Contraindications to its use include heart failure and oliguric renal failure, because of its excellent ability to increase plasma volume, and the presence of von Willebrand's disease, because of its ability to significantly lower all components of Factor VIII-related complex in humans.

Endometrial adenocarcinoma: genetic analysis suggesting heritable site-specific uterine cancer.

UNLABELLED: Genetic factors are clearly integral to the etiology of neoplasia. A cancer family syndrome (Lynch syndrome II) consisting of uterine, colon, and ovarian cancer is recognized, but the heritability of isolated endometrial adenocarcinoma has not otherwise been thoroughly investigated. We have performed pedigree studies in index cases with endometrial adenocarcinoma, using spouses as controls. Preliminary results from 64 probands showed four families in which endometrial adenocarcinoma was diagnosed in at least one first-degree relative of the proband (mother, daughter, sister); none showed relatives with colon or ovarian cancer. In none of the 34 control pedigrees did either a mother or sister have endometrial adenocarcinoma. In four other families, multiple first- and second-degree relatives of probands had adenocarcinoma of the uterus, colon, or ovary, presumably representing a cancer family syndrome (Lynch syndrome II). CONCLUSION: Our preliminary data not only show familial and probably heritable tendencies for endometrial adenocarcinoma, but further suggest that there are at least two distinct forms: (1) the previously described Lynch syndrome II (cancer family syndrome), and (2) a heretofore unemphasized entity characterized by a tendency to endometrial adenocarcinoma alone.

Prognostic factors in stage IB squamous cervical cancer patients with low risk for recurrence.

About one-half of cervical cancer patients whose tumors recur after radical surgery have negative lymph nodes and clear resection margins. We evaluated 95 patients with squamous cell tumors who underwent radical hysterectomy and pelvic lymphadenectomy between January 1975 and December 1985 and who were thought to be at low risk for recurrence to see whether other clinical or histopathologic factors were predictive of tumor recurrence. Detailed retrospective record review and complete pathology review were accomplished for each case. The 5-year actuarial survival rate was 89%. Nine patients developed recurrent disease (9.5%), of whom eight died. Several clinical features were evaluated as possible prognostic factors: patient age (P = .26), patient race (P = .60), cervical diameter (P = .24), extent of gross cervical involvement (P = .36), and presence of contact bleeding (P = .82). Histopathologic features were examined: depth of invasion (P = .31), number of mitoses (P = .42), character of the tumor-stromal border (P = .15), histologic differentiation (P = .02), lymph-vascular space invasion (P = .56), and width of tumor (P = .23). Depth of invasion did correlate with increasing tumor width (P less than .001). Once node- and margin-positive patients are excluded, differentiation may be the only feature useful in identifying patients at risk for recurrence. Because almost one-half of our patients had poorly differentiated tumors, sole use of this feature as a criterion for adjuvant therapy would have resulted in overtreatment of low-risk patients.

Effectiveness and cost benefit of a proposed live cytomegalovirus vaccine in the prevention of congenital disease.

Congenital infection by human cytomegalovirus (CMV) is presently the leading infectious cause of mental retardation and congenital deafness in the United States. Live CMV vaccines in healthy adults have been shown to be safe and to induce immune responses similar to those that occur with natural CMV infection. Yet, only recently has a live CMV vaccine been tested for its protective ability. To evaluate the cost benefit and effectiveness of the proposed live CMV vaccine, we compared the following strategies: routine immunization, selective immunization of those women screened and found to be seronegative, and no immunization. Our results show that, when direct costs alone are considered, routine immunization of healthy women aged 15-25 years is cost beneficial even in populations with CMV seroprevalence as high as 87%. In populations with lower seroprevalence (55%-70%), for every 100,000 women immunized, more than 24 cases of symptomatic congenital CMV infection at birth and a similar number of cases with late sequelae (mainly deafness) would be prevented yearly. Such immunization would result in a net annual saving of $2.5 million.

Natural killing of cytomegalovirus-infected targets in renal transplant recipients.

The ability of peripheral blood mononuclear cells of renal transplant recipients to lyse cytomegalovirus (CMV) infected fibroblasts was determined in an 18-hr 51Cr release assay. Natural killing (NK) against CMV-infected targets was generally depressed for the first two years after transplantation. In three individuals who developed CMV disease after transplantation, NK activity against CMV-infected and uninfected targets rose to high levels following reductions in immunosuppressive therapy and in temporal association with resolution of disease.