19 research outputs found
AIDS-related cardiac tamponade: Is surgical drainage justified?
In order to evaluate the usefulness of surgical drainage in the
treatment of patients with acquired immunodeficiency syndrome
(AIDS)-related cardiac tamponade, we reviewed our experience with
subxiphoid pericardiostomy on 5 consequent such patients. One patient
died in the immediate postoperative period and the remaining 4 died
within 21 weeks after the operation. Similar results have been reported
by other authors who found that surgical drainage has no diagnostic or
therapeutic benefit over pericardiocentesis in this particular group of
patients. Based on our limited experience and the data of the
literature, we feel that surgical drainage cannot be justified as the
primary method of treatment of AIDS-related cardiac tamponade. (C) 2004
by The Society of Thoracic Surgeons
Benign retroperitoneal neural sheath tumors in patients without von Recklinghausen's disease
Benign retroperitoneal neural sheath tumors in patients without von
Recklinghausen’s disease are quite rare and usually presented as
isolated case reports. There are two types of benign neural sheath
neoplasms: schwannoma and neurofibroma. Confusion exists in the
nomenclature of these tumors due to the disagreement upon their cell of
origin. In a collective report from two institutions, three cases with
benign retroperitoneal neural sheath tumors are presented, and the
histological features, diagnostic and therapeutic options are discussed
p53-Dependent ICAM-1 overexpression in senescent human cells identified in atherosclerotic lesions
Most normal somatic cells enter a state called replicative senescence
after a certain number of divisions, characterized by irreversible
growth arrest. Moreover, they express a pronounced inflammatory
phenotype that could contribute to the aging process and the development
of age-related pathologies. Among the molecules involved in the
inflammatory response that are overexpressed in senescent cells and aged
tissues is intercellular adhesion molecule-1 (ICAM-1). Furthermore,
ICAM-1 is overexpressed in atherosclerosis, an age-related, chronic
inflammatory disease. We have recently reported that the transcriptional
activator p53 can trigger ICAM-1 expression in an nuclear factor-kappa B
(NF-kappa B)-independent manner (Gorgoulis et al, EMBO J. 2003; 22: 1567
- 1578). As p53 exhibits an increased transcriptional activity in
senescent cells, we investigated whether p53 activation is responsible
for the senescence-associated ICAM-1 overexpression. To this end, we
used two model systems of cellular senescence: ( a) human fibroblasts
and (b) conditionally immortalized human vascular smooth muscle cells.
Here, we present evidence from both cell systems to support a
p53-mediated ICAM-1 overexpression in senescent cells that is
independent of NF-kappa B. We also demonstrate in atherosclerotic
lesions the presence of cells coexpressing activated p53, ICAM-1, and
stained with the senescence-associated beta-galactosidase, a biomarker
of replicative senescence. Collectively, our data suggest a direct
functional link between p53 and ICAM-1 in senescence and age-related
disorders
Wound infections after minor limb lacerations: Risk factors and the role of antimicrobial agents
Background: The requirement for antimicrobial agents in patients with
minor limb lacerations was prospectively studied.
Methods: The development of wound infections in patients with minor limb
lacerations who received amoxicillin plus clavulanate acid treatment
(group ii, 52 patients) mas studied and compared with patients who did
not (group B, 48 patients).
Results: Wound infection occurred in 6 (11.5%) and 10 (21%) patients
in groups A and B, respectively (p > 0.10). Statistically significant
risk factors for the development of infection were diabetes mellitus
(odds ratio [OR], 15.8; p < 0.001), lower limb lacerations (OR, 33.5;
p < 0.001), lacerations caused by compressive forces (OR, 21.6; p =
0.007), laceration length from 5 to 8 cm (OR, 7.04; p = 0.001), ragged
laceration edge (OR, 2.55; p = 0.049), and skin tension (OR, 2.00; p =
0.006),
Conclusion: The use of antimicrobial agents in minor limb injuries was
not associated with a significant reduction of infection rate. Routine
antimicrobial treatment is discouraged
Transcription factor E2F-1 acts as a growth-promoting factor and is associated with adverse prognosis in non-small cell lung carcinomas
Numerous upstream stimulatory and inhibitory signals converge to the
pRb/E2F pathway, which governs cell-cycle progression, but the
information concerning alterations of E2F-1 in primary malignancies is
very limited. Several in vitro studies report that E2F-1 can act either
as an oncoprotein or as a tumour suppressor protein. In view of this
dichotomy in its functions and its critical role in cell cycle control,
this study examined the following four aspects of E2F-1 in a panel of 87
non-small cell lung carcinomas (NSCLCs), previously analysed for defects
in the pRb-p53-MDM2 network: firstly, the status of E2F-1 at the
protein, mRNA and DNA levels; secondly, its relationship with the
kinetic parameters and genomic instability of the tumours; thirdly, its
association with the status of its transcriptional co-activator CBP,
downstream target PCNA and main cell cycle regulatory and
E2F-1-interacting molecules pRb, p53 and MDM2; and fourthly, its impact
on clinical outcome. The protein levels of E2F-1 and its co-activator
CBP were significantly higher in the tumour area than in the
corresponding normal epithelium (p < 0.001). E2F-1 overexpression was
associated with increased E2F-1 mRNA levels in 82% of the cases
examined. The latter finding, along with the low frequency of E2F-1 gene
amplification observed (9%), suggests that the main mechanism of E2F-1
protein overexpression in NSCLCs is deregulation at the transcriptional
level. Mutational analysis revealed only one sample with a somatic
mutation at codon 371 (Glu –> Asp) and one carrying a polymorphism at
codon 393 (Gly –> Ser). Carcinomas with increased E2F-1 positivity
demonstrated a significant increase in their growth indexes (r = 0.402,
p = 0.001) and were associated with adverse prognosis (P = 0.033 by Cox
regression analysis). The main determinant of the positive association
with growth was the parallel increase between E2F-1 staining and
proliferation (r = 0.746, p < 0.001), whereas apoptosis was not
influenced by the status of E2F-1. Moreover, correlation with the status
of the pRb-p53-MDM2 network showed that the cases with aberrant pRb
expression displayed significantly higher E2F-1 indexes (p = 0.033),
while a similar association was noticed in the group of carcinomas with
deregulation of the p53-MDM2 feedback loop. In conclusion, the results
suggest that E2F-1 overexpression may contribute to the development of
NSCLCs by promoting proliferation and provide evidence that this role is
further enhanced in a genetic background with deregulated pRb-p53-MDM2
circuitry. Copyright (C) 2002 John Wiley & Sons, Ltd
Growth index is independent of microvessel density in non-small-cell lung carcinomas
Induction of angiogenesis is essential for carcinogenesis and
facilitates the processes of tumor development and metastasis. Vascular
endothelial growth factor (VEGF) is an important angiogenic regulator
under physiologic and pathologic conditions. To elucidate the role of
angiogenesis in malignant growth, we evaluated angiogenesis and VEGF
expression in a panel of 68 non-small-cell lung carcinomas (NSCLCs) and
examined their relation with the kinetic parameters, ploidy, and p53
protein status, which have been analyzed previously. Angiogenesis was
estimated as microvascular density (MVD) of the tumor area by CD31
immunodetection. Expression of VEGF was also immunohistochemically
evaluated. All possible associations were assessed through a series of
statistical methods. The mean MVD value was 39 microvessels/mm(2), and
high VEGF immunoreactivity was observed in all specimens, with a mean
percentage of positive cells of 73%. The relation between MVD and VEGF
expression was not statistically significant (P = 0.065). No association
was observed between MVD or VEGF levels with the proliferation index,
apoptotic index, tumor ploidy status, p53 expression, and overall
survival. We conclude that in a subset of NSCLCs, angiogenesis may be
associated with VEGF, but other factors also participate in this
process. Angiogenesis and growth (proliferation and apoptosis) are
independent and probably differentially operated procedures, with only
growth partially controlled by p53 protein expression. Copyright 2002,
Elsevier Science (USA). All rights reserved
Additional characterization of a hexanucleotide polymorphic site in the first intron of human H-ras gene: comparative study of its alterations in non-small cell lung carcinomas and sporadic invasive breast carcinomas
Intron 1 of the human I-I-l ns gene possesses a polymorphism consisting
of repetitions of the GGGCCT consensus. Three alleles have been reported
at this locus. We confirmed that two, pi and PZ, display four and two
repeats, respectively, with their internal sequence structure similar to
that previously described. The third, P3, previously assigned as a
three-unit repetition allele according to its electrophoretic mobility
and with no other information regarding its internal structure, was also
found. Sequence analysis of the P3 allele revealed that it consists of
three perfect repeats of the GGGCCT consensus. This polymorphism is
present only in human c-H-ras gene, although single hexanucleotide
repeats are found scattered within intron 1 of this gene in rodents.
Analysis of this locus in matched tumor/distant normal samples from. (i)
38 patients with nonsmall-cell lung carcinoma (NSCLC), and (ii) 35
patients with sporadic invasive breast carcinoma, revealed: (1) 6.6%
and 19% loss of heterozygosity (LOH) respectively, and (2) 10.5% and
2.9% hexanucleotide instability (III) respectively, detected by the
presence of shifted in length alleles. Shifted alleles exhibited altered
internal sequence structure in comparison to normal ones, suggesting
complex mutational events. The same pattern of alterations was also
detected in tissues adjacent to lung adenocarcinomas and dysplasias
adjacent to squamous cell carcinomas (7.7% LOH, 5.9% III), implying
that abnormalities at this locus may be early events in lung
carcinogenesis. The frequency of alterations (LOH vs. HI) was
significantly different among NSCLC and breast cancer (P=.005), probably
due to the different tumor biology of each system. Finally, altered mRNA
expression of H-ras gene was detected in all cases with HI, but this
finding was also observed in samples without I-II. In view of reports
showing that elements in intron 1 of H-ras gene potentially influence
its transcriptional regulation, from our results we cannot exclude that
the hexanucleotide locus could be an element with possible involvement
in expressional regulation of this gene. (C) 2001 Elsevier Science Tnc.
All rights reserved
Relationship of the K-ras/c-mos expression patterns with angiogenesis in non-small cell lung carcinomas
Background: Neo-angiogenesis is an acquired capability vital for a tumor
to grow and metastasize. Evidence has shown that the mitogen-activated
protein (MAP) kinase pathway is involved in this process. Alterations of
K-ras and c-mos, two pivotal components of this pathway, have been
implicated in non-small cell lung carcinogenesis. In the present report,
we examine, in a series of non-small cell lung carcinomas (NSCLCs), the
status of K-ras and c-mos oncoproteins in correlation with the tumor
neo-angiogenesis state and the major angiogenic factor, vascular
endothelial growth factor (VEGF).
Materials and Methods: c-mos and p-ERK1/2 status was evaluated
immunohistochemically in a total of 65 NSCLCs, whereas the presence of
K-ras mutations was examined by reverse transcriptase-polymerase chain
reaction (RT-PCR) restriction fragment length polymorphism (R-FLP) in
available matched normal tumor material from 56 cases. Microvessel
density (MVD) was estimated by immunodetection of CD31 endothelial
marker, and VEGF expression was assessed by immunohistochemistry. All
possible associations were examined by a series of statistical methods.
Results. Expression of oncogenic activated K-ras and c-mos
overexpression was observed in 12 of 49 (25%) and in 16 of 61 (26%)
informative cases, respectively. Only 1 of the 25 deregulated for K-ras
or c-mos cases exhibited both alterations, suggesting a mutually
exclusive relationship between activated K-ras and c-mos overexpression.
(p = 0.074) in a subset of NSCLCs. In these cases, the MAPK kinase
kinase/MEK/ERK pathway was found to be activated. MVD and VEGF
expression were 36.9 +/- 10.6 mv/mm(2) and 73.1 +/- 20.0%,
respectively. The most intriguing finding was that the
[K-ras(No)/c-mos(P)] profile was significantly associated with low MVD
levels compared to normal cases (p = 0.004); by contrast, no correlation
was found: between the other K-ras/c-mos patterns and MVD. Furthermore,
the former group exhibited the lowest VEGF levels.
Conclusions: The mutually exclusive relationship between mutated K-ras
and c-mos overexpression in a subset of NSCLCs implies a common signal
transduction pathway in lung carcinogenesis. The effect of this pathway
on NSCLC neo-angiogenesis seems to depend upon the status of c-mos,
which acts as a molecular “switch,” possibly exerting a negative
selective pressure on tumor progression