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PubMed2000

[Configural and component processings in face recognition: comparison between inversion and negation effects].

It has previously been reported that subjects show difficulties in recognizing faces which are either inverted or in photographic negative. This study examined whether inversion and negation would disrupt the same aspects of face recognition processes in a same-different decision task for simultaneously presented faces. In a "different" condition, two faces were subtlely changed either in component information (eye size) or configural information (placement of inner features). The results revealed that negation equally disrupted component and configural processings, whereas inversion selectively disrupted configural processing more than component processing. Thus, the negation effect, which has been accounted for in terms of edge vs. surface processing, cannot be accounted for in terms of component vs. configural processing. It is concluded that inversion and negation selectively disrupt different aspects of cognitive processes underlying face recognition.

Adult↗
PubMed2004

Renal perfusion imaging using contrast-enhanced phase-inversion ultrasound.

AIMS: We evaluated different techniques of contrast-enhanced phase-inversion ultrasound to visualize renal perfusion in native kidneys and kidney transplants. MATERIALS AND METHODS: Contrast-enhanced phase inversion ultrasound with different levels of mechanical index and frame rate was performed in 20 kidneys of 13 healthy volunteers. In addition, five dysfunctioning kidneys of patients with chronic renal failure, five functionally intact kidney transplants, three kidney transplants with compensated renal failure, and two kidney transplants with acute rejection were studied. Analysis using a software algorithm for time-resolved perfusion imaging was compared to single-image analysis performed by three independent radiologists. RESULTS: Optimal depiction of renal perfusion was achieved only by using a mechanical index, which was high enough to destroy the microbubbles of the contrast agent (burst imaging) combined with a low frame rate (0.5 images/second). Renal cortex and medulla showed a homogeneous enhancement in kidneys of healthy volunteers and functionally intact renal transplants. Dysfunctioning kidneys of patients with chronic renal failure as well as kidney transplants with compensated renal failure or acute rejection showed a significantly reduced level of enhancement. Computer-assisted time-resolved perfusion analysis was not superior to single-image analysis. CONCLUSION: Renal perfusion patterns of normal and abnormal tissue can be visualized using contrast-enhanced phase-inversion ultrasound imaging.

Adult↗
PubMed2004

[Basic evaluation of a new technique, tailored contrast truck-fluid-attenuated driven inversion-recovery (TACT-FLADIR), to attenuate the signals of both cerebrospinal fluid and inflow artifacts].

The aim of the present study was to evaluate the new tailored contrast truck-fluid-attenuated driven inversion-recovery (TACT-FLADIR) sequence. Technically, this sequence uses a nonselectively driven inversion (DI) pulse as the inversion pulse. The DI pulse has two parameters, number of refocus pulses (NR) and preparation time (TP). Using normal volunteers, we optimized NR and TP to measure signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) of gray matter (GM) and white matter (WM), and to obtain CSF inflow artifacts. TACT-FLADIR was compared with conventional FLAIR using volunteers and patients. Among the optimized parameters, SNR and CNR were dependent on TP, and inflow artifacts were reduced by increasing NR. In brain imaging, TACT-FLADIR provided improvement in both SNR and CNR compared with conventional imaging with suppressed CSF signal and saturated flow artifacts.

Adult↗
PubMed2005

Characterization of hyperechoic focal liver lesions: quantitative evaluation with pulse inversion harmonic imaging in the late phase of levovist.

OBJECTIVE: The aim of this study was to evaluate hyperechoic focal liver lesions with pulse inversion harmonic imaging in the late phase of SH U 508A (Levovist; Schering AG, Berlin, Germany) and to determine whether quantitative evaluation improves the characterization of the lesions. METHODS: Twenty-six patients with hyperechoic liver lesions were enrolled in this study. Pulse inversion harmonic imaging was performed before and after administration of Levovist. Scan data were digitally stored, and each lesion was analyzed with a personal computer-based quantification package. All lesions were confirmed by histologic or triphasic spiral computed tomographic examinations. The intensity was measured in decibels in regions of interest drawn within the lesion and surrounding liver parenchyma. The lesion-liver ratios were than calculated. After contrast agent administration, a ratio equal to or greater than 1 was presumed benign, whereas a ratio of less than 1 was considered malignant. RESULTS: Nine malignant (7 metastases, 1 hepatocellular carcinoma, and 1 cholangiocarcinoma) and 17 benign (14 hemangioma, 1 focal nodular hyperplasia, 1 focal fatty change, and 1 inflammatory pseudotumor) hyperechoic lesions were quantitatively evaluated. All malignant (n = 9) and 2 benign lesions (1 hemangioma and 1 inflammatory pseudotumor) had ratios of less than 1. In 15 of 17 benign lesions, the ratios were equal to or greater than 1. The intensity ratios calculated for benign and malignant lesions showed a statistically significant difference (P < .05). CONCLUSIONS: Pulse inversion harmonic imaging with quantitative evaluation facilitates the differential diagnosis of hyperechoic focal liver lesions. A lesion-liver ratio equal to or greater than 1 predicts a benign nature, assuming that malignant lesions show a ratio of less than 1.

Adult↗
PubMedDate not supplied

Sensory nerve conduction velocity is inversely related to axonal length.

It was found that the axonal length was inversely related to motor conduction velocity (CV). However, it is not clear that sensory CV is inversely related to axonal length. The nerve lengths of the median sensory fascicles from the C6 and C7 intervertebral foramen to the digital branches of the thumb and middle finger were compared in ten cadavers. Sixty healthy subjects (24 men, 36 women; mean age 35, range 24-54 years) had median sensory CV testing. The median sensory nerve action potentials were obtained antidromically in the thumb and middle finger with wrist and elbow. The CVs across the forearm for the thumb and the middle finger fascicles were then calculated. It was found that the nerve length of C7 was longer than C6 with a difference of 3.6 +/- 0.6 cm. The mean forearm CV for the median sensory axons innervating the middle finger (60.0 +/- 3.9 m/s) was slower than the CV for the median sensory axons innervating the thumb (61.4 +/- 4.1 m/s,p = 0.0012). These results demonstrate that sensory CV is slowed by 3.9 m/s per 10 cm of axon length. This study confirms that the inverse relation of CV and axonal length reported in motor axons also applies to the sensory nerves.

Action Potentials↗
PubMed1999

Cell type and gene-specific activity of the retinoid inverse agonist AGN 193109: divergent effects from agonist at retinoic acid receptor gamma in human keratinocytes.

Retinoids are important regulators of epithelial differentiation. AGN 193109 is a high-affinity antagonist and inverse agonist for the nuclear retinoic acid receptors (RARs). Paradoxically, both AGN 193109 and retinoid agonists inhibit the expression of the differentiation marker MRP-8 in normal human keratinocytes (NHKs). TTNPB, an RAR agonist, and AGN 193109 mutually antagonize MRP-8 inhibition at both mRNA and protein levels. We find that this antagonism, which is greatest at an AGN 193109:TTNPB ratio of about 10:1, is absent when either compound is in significant excess. The potent RARalpha-specific agonist, AGN 193836, has no effect on MRP-8 regulation. These data indicate that inverse agonists and agonists suppress MRP-8 in NHKs through RARgamma using distinct and mutually inhibitory mechanisms. The activity of AGN 193109 on MRP-8 is cell type specific. In differentiating ECE16-1 cervical cells, TTNPB inhibits while AGN 193109 induces MRP-8 mRNA levels. The effect of AGN 193109 on genes inhibited by retinoid agonists in NHKs is also selective; expression of the differentiation markers transglutaminase 1 and keratin 6 is not down-regulated by AGN 193109 whereas stromelysin-1 expression is suppressed. These results show a complex gene and cell context-specific interplay between agonist and inverse agonist for the regulation of gene expression.

Calcium-Binding Proteins↗
PubMed1999

Cecal inversion and subsequent colocolic intussusception in a red wolf (Canis rufus gregoryi).

A 2-yr-old female red wolf (Canis rufus gregoryi) presented with weight loss and diarrhea. Abnormal clinical pathology included low serum calcium, sodium, chloride, globulin, and albumin levels. Differential diagnosis included infectious enteritis, intestinal parasitism, inflammatory bowel disease, hepatic or renal disease, and malnutrition. The wolf was treated empirically, but did not improve. A second examination revealed persistent poor musculature and stool quality. Abdominal palpation revealed a firm mass; contrast radiography confirmed an intussusception. Exploratory laparotomy revealed a colocolic intussusception involving the cecum. Following reduction of the colocolic intussusception, cecal inversion (cecocolic intussusception) was identified. Because the cecal inversion could not be reduced, typhlectomy was performed through a colotomy incision. Bacterial culture of peritoneal fluid yielded two strains of Escherichia coli. Postoperatively, the wolf was placed on antibiotics and a soft diet. The diet was gradually returned to its normal formulation and the wolf progressively gained weight. Physical examination 7.5 mo following initial presentation revealed normal body weight and condition. To our knowledge, this is the first recorded incidence of cecal inversion with concurrent colocolic intussusception.

Animals↗
PubMed1999

Agonism and inverse agonism at dopamine D2-like receptors.

1. The processes that follow the binding of ligands to receptors are critical for their physiological functions. In the present paper I intend to review our own work and the work of other laboratories attempting to understand these processes for the dopamine D2-like receptors (D2, D3, D4) and how they contribute to the mechanisms of drug action. It is thought that the key event in agonist action for these receptors is the stabilization, by the agonist, of the agonist-receptor-G-protein ternary complex. The majority of the work I shall describe has been performed using recombinant receptors expressed in cell lines and the mechanisms of receptor action have been probed using ligand binding (competition vs [3H]-spiperone), the stimulation of [35S]-GTP gamma S binding and inhibition of adenylyl cyclase. 2. Measures of the ability of agonists to stabilize the agonist-receptor-G-protein ternary complex may be obtained in ligand-binding studies using the ratio of dissociation constants for the higher and lower affinity states (KI/KH ratio). The stimulation of [35S]-GTP gamma S binding provides a very convenient assay for agonist action and allows the determination of agonist potency and maximal response. Estimates of these quantities may also be obtained from the inhibition of adenylyl cyclase. For a range of agonists at the D2 receptor, there is a tendency for high values of KI/KH to predict high maximal activity and vice versa, but there is no general correlation. This suggests that the simple scheme of agonist action depending on the stabilization of the ternary complex is an over-simplification and further efficacy determining steps need to be included. For a number of receptors, including the D2 and D3 receptors, it has now been shown that there is activity in the absence of agonist (so-called constitutive activity). This agonist-independent activity can be inhibited by compounds previously considered to be antagonists (e.g. the antipsychotic drugs). Therefore, these compounds are inverse agonists rather than antagonists. The mechanism of this inverse agonist effect is unclear and we are examining this using a variety of biochemical approaches, including the use of constitutively active mutants. 3. The mechanisms of agonism and inverse agonism may be probed using biochemical assays and these studies are of great relevance to the understanding of drug action.

Dopamine Agonists↗
PubMedDate not supplied

Inverse correlation between apoptotic (Fas ligand, caspase-3) and angiogenic factors (VEGF, microvessel density) in squamous cell lung carcinomas.

In order to explore whether apoptosis is associated with angiogenesis in lung cancer, immunohistochemistry was employed to determine the pro-apoptotic factors Fas ligand (FasL) and caspase-3 (Cas-3) in 70 squamous cell lung carcinomas. Furthermore, the vascular endothelial growth factor (VEGF) and the microvessel density (MVD) were analyzed. The comparison between MVD and the pro-apoptotic factors demonstrated that the apoptotic factors are inversely related to MVD (Cas-3: p = 0.011, FasL: not significant). In order to confirm this result, FasL and Cas-3 were also compared with the expression of VEGF. Again, an inverse correlation between VEGF and the pro-apoptotic factors was found (Cas-3: p = 0.019, FasL: p = 0.008). The inverse correlation between angiogenesis and apoptosis may be explained by the activation of pro-apoptotic and anti-angiogenic factors caused by hypoxia.

Adult↗
PubMed1999

Inverse association between IgG-anti-kappa and antierythrocyte autoantibodies in patients with cold agglutination.

It has been known for a long time that IgG-anti-F(ab')(2) antibodies (Abs) are able to suppress the B-cell response. We showed that natural IgG-anti-F(ab')(2) autoantibodies appear in the serum of patients with cold agglutination. If the anti-F(ab')2 Ab suppresses cold agglutinin (CA)-producing B cells, one would expect an inverse correlation between the titers of these two Abs. Our study confirmed this correlation. Subsequent experiments showed that some anti-F(ab')(2) Abs bind to the hinge region of IgG. It was difficult to explain how this Ab suppresses CA-producing B cells, which are of IgM isotype. Here we show that patients with cold agglutination have an IgG-anti-kappa light chain autoantibody in their serum. This is another member of the anti-F(ab')(2) Ab group. Because the vast majority of CAs are IgM-kappa Abs, the anti-kappa Ab might suppress CA-producing B cells. If this is the case, there should be an inverse association between the titer of anti-kappa Ab and CA. In a group of 302 patients, we found that high titers of the anti-kappa Ab correlate with low titers of CA and vice versa (P =.009). Interestingly, this association is found only in patients whose disease is caused by noninfectious agents, including mainly B-cell proliferations (P =.0058). Our data show that the inverse correlation is not confined to a particular CA autoantibody specificity. The results are discussed in the light of recent findings showing that anti-IgM Abs may either inactivate or kill tumoral B cells by apoptosis.

Anemia, Hemolytic, Autoimmune↗
PubMed2000

Facilitation of constitutive alpha(2A)-adrenoceptor activity by both single amino acid mutation (Thr(373)Lys) and g(alphao) protein coexpression: evidence for inverse agonism.

The recombinant human alpha(2A)-adrenoceptor (alpha(2A)-AR, RC 2.1. ADR.A2A) can be transformed into a constitutively activated form in CHO-K1 cells by coexpression with a rat G(alphao) protein. Constitutive activity could be enhanced more by both mutation of Thr(373) of the alpha(2A)-AR to a Lys and Cys(351) of the G(alphao) protein by an Ile. The basal [(35)S]GTPgammaS binding response displayed a constitutive alpha(2A)-AR activity that amounted to 21% of the maximal receptor activation as obtained with 10 microM (-)-adrenaline. UK 14304, BHT 920, d-medetomidine, oxymetazoline, and clonidine acted as efficacious agonists. The enhancement of basal activity was entirely blocked (-50 +/- 3%) by ligands that thus appeared to act as inverse agonists (i.e., RX 811059 and its (+)-enantiomer, (+)-RX 821002, RS 15385, and yohimbine); the potencies of the ligands corresponded with their binding affinities for the alpha(2A)-AR. Fluparoxan and WB 4101 displayed partial inverse agonism. Atipamezole and dexefaroxan at 10 microM were virtually free of intrinsic activity and thus acted as neutral antagonists; idazoxan displayed potent partial agonist properties as observed with BRL 44408 and SKF 86466. The inverse agonist activity induced by (+)-RX 811059 could be reversed by atipamezole with a pK(B) value (8.73 +/- 0.07) that was similar to that required for blockade of the UK 14304-mediated response. Constitutive alpha(2A)-AR activation was mainly observed with the G(alphao) Cys(351)Ile protein compared with the pertussis toxin-resistant mutants of the G(alphai) protein subtypes. The observed spectrum of intrinsic activities for the various ligands suggests that pure, neutral antagonists are rather uncommon in this specified alpha(2A)-AR system.

Adrenergic Agonists↗
PubMed2000

Intraventricular CSF pulsation artifact on fast fluid-attenuated inversion-recovery MR images: analysis of 100 consecutive normal studies.

BACKGROUND AND PURPOSE: CSF pulsation artifact is a pitfall of fast fluid-attenuated inversion-recovery (FLAIR) brain MR imaging. We studied ventricular CSF pulsation artifact (VCSFA) on axial FLAIR images and its relationship to age and ventricular size. METHODS: Fast FLAIR axial images were obtained on a 1.5-T unit (8000/150/2 [TR/TE/ excitations], inversion time = 2200, field of view = 24 cm, matrix = 189x256, and 5-mm interleaved sections). Two observers rated VCSFA (hyperintensity on FLAIR images) in the lateral, third, and fourth ventricles by using a three-point ordinal scale in 100 consecutive subjects (ages 20-86 years) with normal brain MR studies. Left-to-right third ventricular width was also measured. RESULTS: Seventy-two subjects had VCSFA in at least one ventricular cavity. The fourth ventricle was the most common site of VCSFA (n = 58), followed by the third ventricle (n = 47) and the lateral ventricles (n = 13). VCSFA was usually severe in the third and fourth ventricles and less severe in the lateral ventricles. Fourth ventricular VCSFA was significantly associated with third ventricular VCSFA. Increasing third ventricular size and, to a lesser extent, increasing age was significantly associated with VCSFA. Ghost pulsation of VCSFA occurred across the brain parenchyma in the phase-encoding direction. VCSFA seen in the fourth ventricle on axial FLAIR images disappeared on sagittal FLAIR images in one subject. CONCLUSION: VCSFA on axial FLAIR images represents inflow artifact caused by inversion delay and ghosting effects. VCSFA might obscure or mimic intraventricular lesions, especially in the third and fourth ventricles. Although common in adults of all ages, VCSFA is associated with advancing age and increasing ventricular size. Thus, altered CSF flow dynamics that occur with ventriculomegaly and aging contribute to VCSFA on axial FLAIR MR images.

Adult↗
PubMed1979

Inverse correlation between species life span and capacity of cultured fibroblasts to metabolize polycyclic hydrocarbon carcinogens.

Many investigators have hypothesized that the aging process may result from an accumulation of DNA damage, and, if valid, this necessitates a means by which this accumulation can be related to the potential life span of an organism. Using an assay for cell-mediated mutagenesis, we have tested multiple diploid fibroblast strains from six mammalian species of widely differing life spans, and found a very good inverse correlation between species life span and ability to activate 7,12-dimethylbenz(a)anthracene (DMBA) to mutagenic forms. We have also found a very good inverse correlation between species life span and ability to activate DMBA to forms capable of covalent binding to DNA. Since the polycyclic hydrocarbon carcinogens such as DMBA and benzo(a)pyrene (BP) are chemically non-reactive in their native forms and must be metabolically activated by mixed-function oxidases to their biologically active forms, these data indicate that the capacity of fibroblasts to activate polycyclic hydrocarbon carcinogens to DNA-damaging forms is a species property related to potential life span. To determine the role of carcinogen metabolism in this phenomenon the capacity of diploid fibroblasts from eight mammalian species to convert BP and DMBA to water-soluble metabolites was then determined. This rate of conversion varies widely among different species and shows a very good inverse correlation with species life span. As a whole, these findings suggest that the ability of cultured cells to metabolize the polycyclic hydrocarbon carcinogens is related to species life span, and may be important in the occurrence of spontaneous cancer.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2000

Assessment of the metabolic chiral inversion of D-leucine in rat by gas chromatography-mass spectrometry combined with a stable isotope dilution analysis.

The stereoselective pharmacokinetics of leucine enantiomers in rats has been investigated to evaluate the inversion of D-leucine to L-enantiomer. After a bolus i.v. administration of D- or L-[2H7]leucine to rats, blood samples were obtained over 6 h after administration and analyzed by a stereoselective gas chromatography-mass spectrometry method. Racemic [2H3]leucine was used as an internal standard. The method involved methyl esterification and subsequent chiral derivatization with (+)-alpha-methoxy-alpha-trifluoromethylphenylacetyl chloride to form the diastereomeric amide. The derivatization made possible the separation of leucine enantiomers with good gas chromatographic behavior. Plasma concentration of both D- and L-[2H7]leucine declined biexponentially, with elimination half-lives of 60 and 14 min, respectively. In contrast to the L-enantiomer, the D-enantiomer had a lower systemic clearance. When D-[2H7]leucine was administered, the L-enantiomer was found to rapidly appear in plasma. About 30% of an administered dose of the D-isomer was stereospecifically inverted to the L-enantiomer. There was no measurable inversion of the L- to D-enantiomer. This methodology has made it possible to evaluate the pharmacokinetics of each enantiomer of amino acids and estimate of chiral inversion after administration of D-amino acids.

Animals↗
PubMed1998

Plasma carotenoid concentrations are inversely correlated with fat mass in older women.

The relationship between body composition, as measured by body mass index and bioelectrical impedance analysis, and baseline plasma carotenoid concentrations was determined in 36 healthy younger (20-40 y) and older (60-80 y) men and women (nine per group). Changes in plasma carotenoid concentrations after 15 d of consuming a controlled high-carotenoid diet were also correlated with body composition (p<0.05). Older women, who had highest percentage of body fat (38%) among the four groups, showed significant and inverse correlations between body composition (defined by body mass index, percentage of body fat, fat mass and fat free mass) and baseline plasma carotenoid concentrations. Younger women, who had 29% percent body fat, showed a significant and inverse correlation only between body mass index and plasma beta-carotene. However, younger and older men, who had lower percentages of body fat (23% and 22%, respectively), did not show any correlation between body composition measures and baseline plasma carotenoid concentrations. The increases of plasma concentrations of alpha-carotene and beta-carotene after 15 d of consuming a high-carotenoid diet were significantly and inversely associated with percentage of body fat and fat mass in older women only. Thus, fat mass appears to influence serum carotenoid concentrations in only certain subjects (i.e. older women) who have relatively high percentage of body fat.

Adipose Tissue↗
PubMed2001

A randomized controlled trial of a passive accessory joint mobilization on acute ankle inversion sprains.

BACKGROUND AND PURPOSE: Passive joint mobilization is commonly used by physical therapists as an intervention for acute ankle inversion sprains. A randomized controlled trial with blinded assessors was conducted to investigate the effect of a specific joint mobilization, the anteroposterior glide on the talus, on increasing pain-free dorsiflexion and 3 gait variables: stride speed (gait speed), step length, and single support time. SUBJECTS: Forty-one subjects with acute ankle inversion sprains (<72 hours) and no other injury to the lower limb entered the trial. METHODS: Subjects were randomly assigned to 1 of 2 treatment groups. The control group received a protocol of rest, ice, compression, and elevation (RICE). The experimental group received the anteroposterior mobilization, using a force that avoided incurring any increase in pain, in addition to the RICE protocol. Subjects in both groups were treated every second day for a maximum of 2 weeks or until the discharge criteria were met, and all subjects were given a home program of continued RICE application. Outcomes were measured before and after each treatment. RESULTS: The results showed that the experimental group required fewer treatment sessions than the control group to achieve full pain-free dorsiflexion. The experimental group had greater improvement in range of movement before and after each of the first 3 treatment sessions. The experimental group also had greater increases in stride speed during the first and third treatment sessions. DISCUSSION AND CONCLUSION Addition of a talocrural mobilization to the RICE protocol in the management of ankle inversion injuries necessitated fewer treatments to achieve pain-free dorsiflexion and to improve stride speed more than RICE alone. Improvement in step length symmetry and single support time was similar in both groups.

Acute Disease↗
PubMed2001

T2 relaxation measurements in X-linked adrenoleukodystrophy performed using dual-echo fast fluid-attenuated inversion recovery MR imaging.

SUMMARY: The purpose of this study was to determine whether dual-echo fast fluid-attenuated inversion recovery MR imaging and corresponding T2 brain maps can show different zones in the affected white matter of patients with cerebral X-linked adrenoleukodystrophy. Ten male patients with cerebral X-linked adrenoleukodystrophy underwent imaging performed using dual-echo fast fluid-attenuated inversion recovery and dual-echo conventional spin-echo MR sequences. Corresponding T2 relaxation maps of the brain were generated. On the basis of dual-echo fast fluid-attenuated inversion recovery images and T2 maps, the affected white matter could be divided into two distinct zones in four patients with cerebral X-linked adrenoleukodystrophy.

Adolescent↗
PubMedDate not supplied

Inverse correlation of apoptotic and angiogenic markers in squamous cell carcinoma of the head and neck.

Angiogenesis is essential for tumour growth and metastasis. The induction of tumour vascularization is mediated by the release of angiogenic peptides. Among these factors, basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) are thought to be the most important. Previous experimental studies indicate that the process of apoptosis, the programme of cell death, may be related to angiogenesis in head and neck carcinogenesis. Therefore, cryostat sections of 49 head and neck squamous cell carcinomas (HNSCC) were investigated immunohistochemically for pro-apoptotic factors caspase-3 and Fas ligand (FasL) using a standard streptavidin-biotin complex procedure. Expression of bFGF, VEGF and MMP-9 served as angiogenic markers. Additionally, intratumoral microvascular density (MVD) was counted by immunostaining of endothelial cells using anti-vWF antibody. Comparing the expression of apoptotic and angiogenic factors, a statistically significant inverse correlation of caspase-3 expression and VEGF and MMP-9 expression was found. Concerning FasL, the correlation of its expression with expression of VEGF, bFGF and MMP-9 was inversely correlated. With respect to vWF-immunostaining, statistical analysis gave a clear inverse correlation between the tumour vascularity and the expression of FasL (p = 0.0008) and caspase-3 (p = 0.0068). Our results suggest that HNSCC tumour angiogenesis contributes to a reduction of apoptosis in tumour cells. This may be explained by the activation of pro-apoptotic factors caused by hypoxia.

Adult↗