Alteration of elastin, collagen and their cross-links in abdominal aortic aneurysms

OBJECTIVES

although the mechanism of arterial dilation and aneurysm development has not been clarified, the degradation of elastin and collagen plays undoubtedly a critical role. We evaluated the elastin and collagen content through the detection of their cross-links in aneurysmal and non-aneurysmal abdominal aortic walls.

MATERIALS AND METHODS

in 26 human abdominal aortic aneurysm specimens obtained during surgery and in 24 autopsy control samples of non-aneurysmal abdominal aorta the tissue content of elastin and collagen cross-links were measured by HPLC. Collagen was also detected by evaluating two characteristic amino acids, 4-hydroxyproline (4-hypro) with a colorimetric method and 5-hydroxylysine (5-hylys) by gas chromatography.

RESULTS

significantly fewer elastin cross-links were found in aneurysm samples compared to controls (desmosines and isodesmosines: 90% reduction; p<0.01). The opposite was true for pyridinoline collagen cross-links (350% increase) and deoxypyridinolines (100% increase, p=0.01). Tissue content of 5-hylys, 4-hypro and total amino acids were reduced significantly by 50% in aneurysmal samples.

CONCLUSIONS

beside confirming decreased elastin content in aneurysmal walls, these results show a concurrent increase of collagen cross-links. Since total collagen markers were decreased (decreased 4-hypro and 5-hylys) it is reasonable to suggest that in aneurysmal aortic walls old collagen accumulates cross-links while new collagen biosynthesis is somehow defective.

Cetirizine, a second-generation H1 antagonist, modulates Rantes and MCP-1 levels in allergic rhinitis

Chemokines and their receptors are involved in several allergic diseases. We measured RANTES and MCP-1 levels in sera of allergic rhinitis patients, and also we evaluated the effect of cetrizine, a second-generation H1 antagonist, on these chemoattractant proteins. 15 subjects were studied (10 males and 5 females; mean age: 26.7 years). They were suffering from perennial or seasonal allergic rhinitis induced by Dermatophagoides pteronyssinus (8 patients) or by grasses (7 patients). RANTES and MCP-1 serum levels were detected with an enzyme immunoassay before and after two weeks of treatment with 10 mg of cetirizine daily, and again after two weeks of washout. Baseline serum levels of RANTES and MCP-1 chemokines were significantly higher (p &lt; 0.02 and p = 0.007, respectively) in allergic patients than in the healthy control group. Cetirizine resulted in a significant decrease in RANTES (p &lt; 0.02) and MCP-1 (p = 0.003) versus baseline values. There is an increase in RANTES and MCP-1 in allergic rhinitis, which is counteracted by cetirizine.

Mammary implants: laboratory simulation of recreational diving conditions

To ascertain whether mammary implants are prone to changes in conformation or structure if they are submitted to recreational dives, eight mammary implants were submitted to 40 simulated dives to imitate an average recreational diving schedule. Matching implants were used as a control group. Photographs were taken before and after completion of the protocol. All implants were observed for changes in volume and checked for integrity. Variations in density were evaluated using a Tc scan. No changes in volume occurred after each dive. None of the implants showed ruptures, and Tc scanning failed to reveal any differences in density between tested and control implants. Cohesive-gel implants submitted to the simulated dives showed some morphological alterations. This study indicates that the mammary implants tested could be implanted in a sports diver, but raises concern about whether the increased exposure to stress could negatively affect their durability.

[Pathogenic protozoans in man: differential characterization of Entamoeba histolytica/Entamoeba dispar complex, Acanthamoeba spp., Microsporidia]

The review summarizes the results in the main parasitological topics of our Lab: amoebic infections due to Entamoeba histolytica/Entamoeba dispar complex and to Acanthamoeba spp. respectively, and human infections caused by microsporidia. Different rapid and advanced techniques have been included in the standardized diagnostic protocols for each topic, and a critical comparison among them was made, in order to define the gold standard diagnostic method: a) E. histolytica/E. dispar: in vitro culture, zymodeme typization, biomolecular identification (PCR), immunoenzymatic assay (ELISA) for direct detection in stools of specific surface antigenic lectins; b) Acanthamoeba spp.: in vitro culture, light and ultrastructural characterization, species identification by immunofluorescence method with monoclonal antibodies, in vitro pharmacological studies; c) Microsporidia: ultrastructural (TEM), biomolecular (PCR), biochemical and immunological (SDS-PAGE, Immunoblotting) studies for species identification, use of advanced ultrastructural techniques ("freeze-etching", "deep-etching") in order to deepen the spore wall structure, to study the cytoskeletal function of actin and to define the mode of infection, in vitro pharmacological assays on some inhibitors of chitin-synthases.

Urinary 11-dehydro-thromboxane B(2) and coagulation activation markers measured within 24 h of human acute ischemic stroke

The aim of this study was to determine the extent of change in platelet and coagulation markers in the acute phase of ischemic stroke and to assess the utility of marker measurement in stroke subtype classification. Urinary 11-dehydro-thromboxane B(2) (11-dTXB2), a marker of in vivo platelet activation, and markers of coagulation activation, including prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT), and fibrinogen, were measured in 25 patients with ischemic stroke within 24 h of onset of symptoms. Marker levels in patients with ischemic stroke were compared with those in 19 age-matched controls who had not taken aspirin for at least 2 weeks before sampling and 25 healthy controls. Median marker levels were significantly increased in stroke over those in age-matched controls for fibrinogen (344 vs. 289 mg/dl; P=0.030), F1+2 (1.40 vs. 0.80 nmol/l; P=0.003), and TAT (6.65 vs. 2.20 microg/l; P<0.0001). Median marker levels for seven patients with cardioembolic stroke and 18 with non-cardioembolic stroke were not significantly different for any marker test. Eight patients taking aspirin at the time of the stroke had significantly lower 11-dTXB2 values than patients not taking aspirin (964 vs. 4,314 pg/mg of creatinine; P=0.007). Stroke patients not taking aspirin had significantly higher 11-dTXB2 concentration than age-matched controls (4,314 vs. 1,788 pg/mg of creatinine; P=0.006). Coagulation and platelet activation markers are increased in the acute phase of stroke regardless of the clinical mechanism. This finding suggests that the markers may not be useful for predicting clinical subtype of ischemic stroke in the acute phase.

Proliferation and activation of bronchial epithelial cells in corticosteroid-dependent asthma

BACKGROUND

Structural and functional characteristics of bronchial epithelial cells in corticosteroid-dependent asthma are unknown.

OBJECTIVE

In bronchial biopsy specimens from 16 control, 9 untreated asthmatic, 9 inhaled corticosteroid-treated asthmatic, and 19 corticosteroid-dependent asthmatic subjects, we evaluated epithelium morphology and patterns of cell apoptosis, proliferation, and activation.

METHODS

We used the terminal deoxynucleotidyl-mediated dUTP nick end labeling (TUNEL) technique to study apoptosis. Immunohistochemistry was used to evaluate the expression of molecules related to apoptosis (such as Bcl-2 and P53), cell proliferation (PCNA), and cell activation (NFkappaB and CD40/CD40-L).

RESULTS

Epithelium thickness was higher in corticosteroid-dependent asthmatic and control subjects than in inhaled corticosteroid-treated and untreated asthmatic subjects (P < .0001 and P <.0003). Very few TUNEL-positive epithelial cells were found in the 4 groups. Bcl-2 expression was higher in all groups of asthmatic subjects than in controls (P < .001). In corticosteroid-dependent asthmatic subjects, PCNA, NFkappaB, and CD40-L expression was higher than in inhaled corticosteroid-treated asthmatic (P < .001), untreated asthmatic (P <.001 and P < .04), and control (P < .01) subjects. CD40 expression was greater in corticosteroid-dependent asthmatic and untreated asthmatic subjects than in inhaled corticosteroid-treated asthmatic subjects (P < .0001 and P < .0006) and controls (P < .02 and P < .03). In corticosteroid-dependent asthma, PCNA expression was correlated with the epithelium thickness (P < .007).

CONCLUSION

This study shows that in bronchial epithelial cells of corticosteroid-dependent asthma, markers of cell survival and proliferation are coexpressed with markers of cell activation, suggesting that in this disease epithelium repair is associated with a persistent activation state of epithelial cells.

Clinical features of spontaneous intracerebral hemorrhage in Hispanics and non-Hispanic Whites in New Mexico: a community study

OBJECTIVES

To compare clinical features of spontaneous intracerebral hemorrhage (ICH) between Hispanics and non-Hispanic Whites in Albuquerque, New Mexico, occurring during the year 1993.

DESIGN

Analysis of data collected during a study of ICH incidence in a community.

METHODS

Review medical records with multiple relevant cerebrovascular diagnostic discharge codes in all 9 acute care hospitals in Albuquerque, and in the records of the State Medical Examiner. All suspected cases were verified by cerebral computed tomography or autopsy. Vascular risk factors, test results, and acute outcome were abstracted.

RESULTS

There were 38 Hispanics and 46 non-Hispanic Whites with ICH. We found no statistically significant differences between these two ethnic groups in the prevalence of hypertension or diabetes mellitus, in hematoma volume, in seasonal fluctuation of ICH incidence, or in acute mortality. However, based on our sample size, only large differences in the prevalence of risk factors between these two ethnic groups could be detected with statistical significance (>20-30 percentage points). There was a trend toward a higher proportion of subcortical ICH (centered in the basal ganglia, brainstem, or cerebellum) in Hispanics (82%) than in non-Hispanic Whites (62%, P=.09).

CONCLUSIONS

The higher proportion of subcortical ICH among the Hispanics suggests that chronic hypertension may play a greater role as a risk factor for ICH in this ethnic group than in non-Hispanic Whites in New Mexico. Our findings should be confirmed by larger community studies.

Spectrum of antiphospholipid antibodies (aPL) in patients with cerebrovascular disease

BACKGROUND

The association of stroke and antiphospholipid antibodies (aPL) other than anticardiolipin antibodies (aCL) is not well documented.

OBJECTIVE

To report the distribution of aCL, antiphosphatidylethanolamine (aPE), and antiphosphatidylserine (aPS) aPL among patients with symptomatic cerebrovascular disease evaluated by our Stroke Service at Indiana University Hospital from January 1997 to November 1999.

METHODS

We retrospectively reviewed medical records from 1997 to 1999 at Indiana University Hospital for all patients with symptomatic cerebrovascular disease using the International Statistical Classification of Diseases, 9th Revision, (ICD-9) codes. We identified patients with elevated titers of aPL. Sera from these patients were obtained within the first 30 days of the index event. We included only those patients for whom the serum samples were tested in a single laboratory by an in-house enzyme-linked immunosorbent assay (ELISA) for immunoglobulin G (IgG) immunoglobulin A (IgA) and immunoglobulin M (IgM) aCL, aPE, and aPS. We examined the clinical presentation, stroke risk factors, associated rheumatologic disorders, and distribution of aPL specificity and isotype.

RESULTS

Thirty-four of 185 patients, 26 women (76%), with a mean age of 46 years, and 8 men (24%) with a mean age of 46 years, had aPL. Nine patients had transient ischemic attacks (TIA), 25 suffered strokes, 23 had ischemic infarcts, and 2 had hemorrhagic infarcts (1 had a superior sagittal sinus thrombosis with bilateral hemispheric hemorrhagic infarcts, and one had bilateral hemorrhagic infarcts associated with systemic lupus erythematosus [SLE]). Six patients had SLE. The most common stroke risk factors were cigarette smoking (38%) and arterial hypertension (26%). Approximately two thirds (60%) of patients had a single positive aPL finding: aPE in 35%, aCL in 18%, and aPS in 6%. Multiple specificities were seen in 40%. IgA was the only aPL antibody isotype detected in 26% of the patients, IgG was the lone isotype in 24%, and IgM alone in 12%. Multiple aPL isotypes were detected in 38% of patients. Five patients (15%) presented with aPE IgA as the exclusive aPL.

CONCLUSION

In our series, aPE was the most frequent finding in stroke patients who were suspected to have an associated aPL syndrome. These specific types of aPL may be present relatively often in stroke patients and are often not assessed. Further studies are needed to determine how specific these aPL are in stroke versus other acute illnesses and versus healthy controls, and how these aPL are associated with stroke risk.

Moyamoya: Indiana University Medical Center experience

BACKGROUND

Moyamoya usually presents with cerebral ischemia in children and intracranial hemorrhage in adults. Treatment remains controversial.

DESIGN AND OBJECTIVE

We reviewed our experience from June 1995 to August 1999 of 20 adult and pediatric angiographically diagnosed patients with moyamoya to report their clinical presentation, radiological findings, management, and clinical outcomes.

RESULTS

The mean age of patients at symptom onset was 17 years (range, 2-54 years). Patients were divided into 2 age groups (group 1, <18 years; group 2, > or =18 years). There were 13 patients in group 1 and 7 patients in group 2. Ischemic strokes or transient ischemic attacks were the predominant initial presentations in both groups. One patient in group 2 had an intraparenchymal brain hemorrhage. Five patients received medical treatment, and 15 had surgical revascularization. The mean time from symptom onset to surgical procedure was significantly longer for patients in group 1 than for those in group 2 (P =.03). The mean follow-up time was 36 months. One patient in group 1 had an ischemic stroke. There was no difference in stroke recurrence, mortality, or modified Rankin scale score among medically or surgically treated patients.

CONCLUSIONS

Moyamoya disease may have a different presentation and more benign natural history in our population than in Asian populations. Our findings emphasize the need to better understand the natural history of patients with moyamoya as well as the clinical benefit of different treatment modalities. Structured multicenter randomized clinical trials are needed to further assess the best treatment modalities for patients with moyamoya in the United States.

Quantitative analysis of Fas and bcl-2 expression in hematopoietic precursors

BACKGROUND AND OBJECTIVES

We investigated the expression of bcl-2 and CD95 (Apo1-/Fas) on CD34+ cells obtained from bone marrow (BM), mobilized peripheral blood (MPB), and umbilical cord blood (UCB) samples. The expression of bcl-2 and Fas was then compared with that of other markers usually associated with immaturity; functional tests using the agonistic antibody anti- Fas CH11 were also carried out.

DESIGN AND METHODS

The analysis was performed by flow cytometry on purified CD34+ cells in a three (CD95 PE, CD34 APC and CD71 FITC) and in a four (CD38 PE, HLA-DR PerCP, CD34 APC and bcl-2 FITC) fluorescence assay.

RESULTS

The results were expressed as mean fluorescence index (MFI); bcl-2 expression was significantly higher (p < 0.001) in BM (3.73 +/- 0.63) than in MPB (2.47 +/- 0.39) and UCB (2.38 +/- 0.58); Fas was significantly less expressed (p < 0.001) in UCB (1.27 +/- 0.78) than in MBP (3.63 +/- 2.19) and BM (4.56 +/- 1.69). CD34 expression was significantly (p < 0.001) brighter in UCB compared to in MBP and BM, while CD38 and CD71 were significantly (p = 0.005 and p < 0.001, respectively) more expressed in BM than in MPB and UCB. Fas values were directly correlated to CD38; both Fas and bcl-2 were directly related to CD71 and inversely to CD34. Culture assays showed that hematopoietic precursor cells from BM, MPB and UCB had a low susceptibility to undergo Fas-mediated apoptosis.

INTERPRETATION AND CONCLUSIONS

In conclusion, bcl-2 and Fas are less expressed in UCB than in MPB and BM; early hematopoietic precursor cells are relatively resistant to CD95-triggered apoptosis; the observed correlation between Fas/bcl-2 and markers of immaturity suggests that they may be determinants of commitment in early hematopoietic precursors.

Protocol violations in community-based rTPA stroke treatment are associated with symptomatic intracerebral hemorrhage

BACKGROUND

Recombinant tissue plasminogen activator (rTPA) is an established treatment for acute ischemic stroke. The rate and type of protocol violations in rTPA use and their effect on patient outcomes in this setting are not well understood.

OBJECTIVE

The objective of this study was to examine associations between protocol violations and outcomes in community-based rTPA use.

METHODS

We reviewed medical records of stroke patients treated with rTPA in 10 acute-care hospitals in Indianapolis from July 1996 to February 1998 and assessed complications and outcome. Retrospective National Institute of Health Stroke Scale (on admission and discharge), Canadian Neurological Scale, and length of hospital stay were calculated. Appropriate use of rTPA was determined by the National Institute of Neurological Disorders and Stroke (NINDS) protocol.

RESULTS

Fifty patients (mean age, 66 years; 76% white; 56% men) were treated by general neurologists (70%), stroke neurologists (24%), or emergency physicians (6%). Mean times to hospital arrival, brain CT, and start of rTPA infusion were 44, 86, and 141 minutes, respectively. In-hospital mortality rate was 10% (4 intracerebral hemorrhage [ICH], 1 cardiogenic shock). Complications were more frequent among patients with protocol violations (n=8) compared with those without all hemorrhages (75% versus 10%, P:<0.001), symptomatic ICH (38% versus 5%, P:<0.02), and ICH attributable to rTPA, occurring within 36 hours (38% versus 2.4%, P:<0.01), respectively.

CONCLUSIONS

NINDS protocol violations are relatively common and are associated with symptomatic cerebral and systemic hemorrhages. When the NINDS protocol is strictly followed, hemorrhage rates in community-based rTPA use are similar to those in the NINDS trial.

Prevention of pin track infection in external fixation with silver coated pins: clinical and microbiological results

Pin tract infection is a frequent complication of external fixation; according to literature its frequency ranges from 2-30%. The recent introduction of silver coating of polymeric materials was found to decrease bacterial adhesion; its clinical use with Foley catheters and central venous catheters led to significant results. To verify the ability of the same silver coating to decrease the bacterial colonization on external fixation screws, a prospective randomized study was carried out on 24 male patients; a total of 106 screws were implanted in the lower limb to fix femoral or tibial diaphyseal fractures: 50 were coated with silver and 56 were commercially available stainless steel screws. Although the coated screws resulted in a lower rate of positive cultures (30.0%) than the uncoated screws (42.9%), this difference was not statistically significant (p = 0.243). The clinical behavior of the coated screws did not differ from that of the uncoated ones. Furthermore, the implant of silver-coated screws resulted in a significant increase in the silver serum level. These results led us to consider it ethically unacceptable to continue this investigation.

Prevention of pin track infection in external fixation with silver coated pins: clinical and microbiological results

Pin tract infection is a frequent complication of external fixation; according to literature its frequency ranges from 2-30%. The recent introduction of silver coating of polymeric materials was found to decrease bacterial adhesion; its clinical use with Foley catheters and central venous catheters led to significant results. To verify the ability of the same silver coating to decrease the bacterial colonization on external fixation screws, a prospective randomized study was carried out on 24 male patients; a total of 106 screws were implanted in the lower limb to fix femoral or tibial diaphyseal fractures: 50 were coated with silver and 56 were commercially available stainless steel screws. Although the coated screws resulted in a lower rate of positive cultures (30.0%) than the uncoated screws (42.9%), this difference was not statistically significant (p = 0.243). The clinical behavior of the coated screws did not differ from that of the uncoated ones. Furthermore, the implant of silver-coated screws resulted in a significant increase in the silver serum level. These results led us to consider it ethically unacceptable to continue this investigation.

Prevention of pin track infection in external fixation with silver coated pins: clinical and microbiological results

Pin tract infection is a frequent complication of external fixation; according to literature its frequency ranges from 2-30%. The recent introduction of silver coating of polymeric materials was found to decrease bacterial adhesion; its clinical use with Foley catheters and central venous catheters led to significant results. To verify the ability of the same silver coating to decrease the bacterial colonization on external fixation screws, a prospective randomized study was carried out on 24 male patients; a total of 106 screws were implanted in the lower limb to fix femoral or tibial diaphyseal fractures: 50 were coated with silver and 56 were commercially available stainless steel screws. Although the coated screws resulted in a lower rate of positive cultures (30.0%) than the uncoated screws (42.9%), this difference was not statistically significant (p = 0.243). The clinical behavior of the coated screws did not differ from that of the uncoated ones. Furthermore, the implant of silver-coated screws resulted in a significant increase in the silver serum level. These results led us to consider it ethically unacceptable to continue this investigation.