Microcalcifications increase coronary vulnerable plaque rupture potential: a patient-based micro-CT fluid-structure interaction study

Asymptomatic vulnerable plaques (VP) in coronary arteries accounts for significant level of morbidity. Their main risk is associated with their rupture which may prompt fatal heart attacks and strokes. The role of microcalcifications (micro-Ca), embedded in the VP fibrous cap, in the plaque rupture mechanics has been recently established. However, their diminutive size offers a major challenge for studying the VP rupture biomechanics on a patient specific basis. In this study, a highly detailed model was reconstructed from a post-mortem coronary specimen of a patient with observed VP, using high resolution micro-CT which captured the microcalcifications embedded in the fibrous cap. Fluid-structure interaction (FSI) simulations were conducted in the reconstructed model to examine the combined effects of micro-Ca, flow phase lag and plaque material properties on plaque burden and vulnerability. This dynamic fibrous cap stress mapping elucidates the contribution of micro-Ca and flow phase lag VP vulnerability independently. Micro-Ca embedded in the fibrous cap produced increased stresses predicted by previously published analytical model, and corroborated our previous studies. The 'micro-CT to FSI' methodology may offer better diagnostic tools for clinicians, while reducing morbidity and mortality rates for patients with vulnerable plaques and ameliorating the ensuing healthcare costs.

A dose dense low toxicity salvage regimen for histologically aggressive non-Hodgkin’s lymphoma (NHL): Gemcitabine, rituximab, oxaliplatin combination (GROC) plus pegfilgrastim

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High dose chemo/autologous stem cell transplant (ASCT) is standard treatment for relapsed aggressive NHL. However many are unable to receive ASCT because they are refractory to salvage therapy, too old or too sick. More effective, less toxic salvage regimens are needed prior to ASCT. Gemcitabine (G) and Oxaliplatin (O) are active agents in NHL and exhibit synergism so their combination is attractive to explore together with Rituximab (R). We hereby report the results of a phase I-II trial designed to explore the GROC regimen administered every 14 days with Pegfilgrastim support. After the first 6 pts were entered, the phase I portion was completed; recommended dose: R = 375 mg/m2 on day 1, G = 1,250 mg/M2 on day 2, O = 100 mg/m2 on day 2 and Neulasta 6 mg day 3. So far we have entered 21 pts of which 19 are currently evaluable. Median age = 58 (range = 27–88); 9 were refractory to 1st line therapy, 5 were on 1st relapse, 3 on 2nd and 2 >2 relapses, 12 had high LDH, 10 high Beta-2-M. Using IWG/PET criteria ORR = 79%, CR = 42%, PR = 37%. There was a correlation between response to preceding chemo regimen and response to GROC ( table ). In 6 the response to GROC was better than to preceding regimen while only in 2 was the response worse. At 1 year the projected OS is 49% and PFS 34%. So far, only 5 of 15 responders have relapsed. An intriguing finding is that in 6 of 15 responders, PFS has been longer with GROC than with preceding regimen and shorter in only 1. Grade 4 hematologic toxicity occurred only once. No neutropenic fevers seen. Most common toxicity was reversible transaminitis in 13 (grade 1–2 in 10, grade 3 in 3), neuropathy in 9 (grade 1–2 in 8, grade 3 in 1), diarrhea in 3 (grade 4 in 1). We could deliver courses at a median interval of 14 days. Conclusions: 1- GROC is an effective dose dense salvage regimen. 2- It appears effective even in pts with poor prognostic features including primary refractory disease. 3-Hematologic toxicity is very low and non-hematologic toxicity acceptable.

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[Table: see text]

Bioactive oleanolic acid saponins and other constituents from the roots of Viguiera decurrens

The bisdesmoside oleanolic acid saponin, 3-0-(methyl-beta-D-glucuronopyranosiduronoate)-28-0-beta-D-glucopyranosyl-oleanolate along with nine known compounds (two diterpenic acids, one chromene, three triterpenes, one steroidal glycoside, and two monodesmoside oleanolic acid saponins), were obtained from Viguiera decurrens roots. The chemical structure of the bisdesmoside oleanolic saponin was determined by chemical and NMR spectral evidence. A mixture of monodesmoside saponins displayed cytotoxic activity against P388 and COLON cell lines (ED50= 2.3 and 3.6 microg/ml, respectively). Two of the known compounds showed insecticidal activity against the Mexican bean beetle larvae (Epilachna varivestis).

Dealing with diversity: recruiting churches and women for a randomized trial of mammography promotion

There is little documentation about the recruitment process for church-based health education programs. In this study, the authors recruit African American, Latino, and white churches and women members (age 50 to 80) for a randomized church-based trial of mammography promotion in Los Angeles County. Efforts to enhance recruitment began 10 months before churches were invited to participate and included a variety of community-based strategies. Subsequently, 45 churches were recruited over a 5-month period through group pastor breakfast meetings and church-specific follow-up. In close collaboration with the 45 churches, the authors administered church-based surveys over 6 months and identified 1,967 age-eligible women who agreed to be contacted by the program team. It was found that an extended resource intensive period of relationship-building and community-based activities were necessary to conduct church-based programs effectively, particularly among older and ethnically diverse urban populations.

Urinary assays for desmosine and hydroxylysylpyridinoline in the detection of cirrhosis

BACKGROUND/AIMS

Non-invasive markers of liver fibrosis have great potential for both the diagnosis and therapy of liver disease and cirrhosis. The aim of this study was to evaluate the potential of urinary amino acids desmosine (DES) and isodesmosine (IDES) derived from the breakdown of elastin and hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP) derived from fibrillar collagen in diagnosing chronic liver disease.

METHODS

We studied 48 patients with chronic liver disease who had varying degrees of liver fibrosis, graded 0-6 using a modified Knodell score, and 20 control subjects without liver disease. Urinary DES (microg/g creatinine) and HP (nmol/mmol creatinine) were measured by an isotope dilution, high performance liquid chromatography method. For liver disease patients, aminoterminal propeptide of type III procollagen (PIIINP) and alanine aminotransferase were determined. The urine and serum markers were correlated to degree of fibrosis and inflammation on liver biopsies. Differences between groups were analyzed by ANOVA and multiple linear regression was applied to determine independence of variables. Sensitivity, specificity and receiver operating curves were derived for each marker.

RESULTS

In the 17 patients with liver fibrosis score of 5-6, mean urinary DES, IDES, HP and LP were all significantly greater than in the control group (p<0.05). Urinary DES and IDES correlated best with fibrosis score, r=0.61 for both markers. The correlation coefficient between serum PIIINP and fibrosis score was 0.47. Urinary DES and HP each had an overall diagnostic accuracy of 77% for fibrosis. Combining markers improved accuracy to over 80%. No correlation was seen between the urinary markers and inflammation scores.

CONCLUSIONS

Urinary DES and HP are potentially useful clinical markers for liver fibrosis, especially when used in combination or in association with PIIINP.

Hemostatic abnormalities associated with monoclonal gammopathies

To confirm and expand previous observations about the association of monoclonal gammopathies with hemostatic defects, a prospective evaluation was made in 42 patients with lymphoplasmacytic disorders. The incidence of bleeding complications was low, despite the diversity of abnormal hemostatic tests observed in these patients. Patients with myeloma frequently had abnormal coagulation tests, including thrombin time (64%), fibrin degradation products (32%), platelet aggregation tests with different agonist (30% to 55%), and bleeding time (22%). The lack of platelet response to ristocetin and normal ristocetin cofactor activity in four patients with myeloma may suggest a Bernard-Soulier-type defect. Serum viscosity was negatively correlated with platelet aggregation with collagen, ristocetin, and adenosine diphosphate. In patients with immunoglobulin myeloma, there was a positive correlation between an increased viscosity and a prolonged thrombin time. This study demonstrates the wide variety of coagulation abnormalities in lymphoplasmacytic disorders, usually without significant clinical implications.

Self-disclosure of HIV infection: Preliminary results from a sample of Hispanic men

We examined self-disclosure of HIV infection among 101 seropositive Hispanic men residing in Los Angeles. Results indicated that disclosure was highly selective and presumably influenced by the social, psychological, and material consequences of informing others about one's medical condition. Subjects tended to inform significant others such as parents, friends, and lovers than less significant others such as employers, landlords, and religious leaders. There was a relatively high rate of disclosure (75%) to doctors/dentists who were not treating subjects for HIV infection. Gay and bisexual subjects (89% of the sample) were more inclined to disclose their HIV serostatus to homosexual or bisexual others than to heterosexuals and to inform those who were aware of their sexual orientation. Disclosure increased with severity of disease independently of length of time since testing seropositive. Self-rated negative changes in appearance correlated with disclosure to less significant others. The role of cultural attitudes and values in self-disclosure of HIV infection is discussed.

HIV-infected men's practices in notifying past sexual partners of infection risk

The researchers studied the self-reported practices of men infected with the human immunodeficiency virus (HIV) in Los Angeles concerning notifying past sexual partners of their risk of infection. The sample of 111 men consisted of 87 Hispanics, 14 whites, 9 blacks, and 1 Asian. Ninety-three percent identified themselves as homosexual or bisexual, and 13 percent reported having injected a nonprescription drug. Seventy-five percent had tested HIV seropositive within the previous 8 months. Subjects were asked about notifying sexual partners with whom they had contact in the 12-months before the subject tested HIV seropositive. Of the 111 subjects, 39 (35 percent) reported that they had attempted to inform 1 or more past partners. Of those who attempted, 30 subjects (76.9 percent) reported notifying at least 1 partner. Overall, the 111 subjects reported a total of 926 individual sexual partners during the 12 months; 51 partners (5.5 percent) were informed of their risk by the subjects. A multivariate logistic regression analysis indicated that those with the most past sexual partners were least likely to attempt to notify any partner. The same inverse relationship was obtained for actual notification and may stem in part from the greater frequency of nonidentifiable partners among those reporting many encounters. The extent and quality of posttest counseling regarding partner notification was not assessed. However, rates of attempted notification were nonsignificantly higher among those who received private professional counseling, who belonged to a support group, or who received social support from family or friends. The data suggest that without concerted and culturally appropriate counseling, many HIV infected persons do not attempt to notify past sexual partners of their risk.

Self-disclosure of HIV infection to sexual partners

Self-disclosure of HIV infection to current sexual partners was examined in 138 seropositive men, mostly lower income Hispanics, from Los Angeles. Forty-five percent had been sexually active since learning their serostatus. Of these, 52% had kept their infection secret from one or more partners. The likelihood of disclosure decreased in direct proportion to the number of partners. Nondisclosure occurred in conjunction with unprotected receptive and insertive anal intercourse. Potential factors promoting nondisclosure are discussed.

Bile salt metabolism in tropical sprue

Mean and peak jejunal bile salt concentrations during digestion of a standard fat meal were found to be significantly lower in six Puerto Rican patients with untreated tropical sprue, all of whom had steatorrhoea, than in six asymptomatic subjects who had normal fat absorption. Bile salt pool size and turnover time did not differ significantly in the two groups.It is suggested that bile salt concentrations may be reduced in the proximal small intestine of patients with tropical sprue as a result of excessive dilution by intestinal fluid. The finding of low bile salt concentrations in two asymptomatic subjects indicates that bile salt lack alone may not be sufficient to produce steatorrhoea.