[Bone anchored hearing aid (BAHA): clinical evaluation]

The bone-anchored hearing aid (BAHA) allows direct bone-conduction through a titanium implant. This avoids skin irritation and seems to improve the sound quality when compared with a conventional bone hearing aid. Aim of this work was to evaluate this new hearing-aid.

PATIENTS AND METHODS

9 patients have been operated on between May 1994 and April 1997. Two aural atresia and 7 radical mastoidectomy; 6 had prior conventional bone hearing aid and one a bilateral air-conduction hearing aid. Their mean bone conduction threshold was 28 dB (17-38 dB). Their maximum speech discrimination score was 100%. Audiological tests and questionnaires were used for the evaluation.

RESULTS

The mean follow-up was 9-months (3-35). Osseointegration succeeded in the 9 cases. Skin tolerance was excellent in 6 cases. 3 patients had transient adverse skin reactions, with one having needed a revision surgery under local anesthesia. All patients use their BAHA everyday. The mean prosthesis gain was 36 dB (20-50 dB). Eight patients completed the questionnaire. Patients reported an overall satisfaction score between 9 and 10 (range 6-10). BAHA advantageously replaced the prior hearing aid (mean satisfaction score: 9.1 for BAHA versus 5.9). The only complaints were sensitivity to wind noise and lack of a phone connexion.

Influence of alcohol consumption and various beverages on waist girth and waist-to-hip ratio in a sample of French men and women

OBJECTIVE

The goal of the present study was to assess the association between alcohol consumption and abdominal fat deposition in France, a country where wine is the most commonly consumed alcoholic beverage.

METHODS

We analyzed the association between alcohol consumption and various markers of body weight, in a population sample recruited in three distinct geographical areas of France (MONICA centers). This sample included men (n = 1778) and women (n = 1730) aged 35- 64 y, randomly selected from electoral rolls. Alcohol consumption was assessed with a quantitative frequency questionnaire.

RESULTS

Alcohol intake ranged from 0-1655 ml of alcohol per week. Wine was the main source of alcohol, representing 67% of total alcohol intake in both genders. In men, there was no association between alcohol intake and body mass index (BMI) or body weight, whereas in women, alcohol consumption was inversely correlated with BMI (P < 0.0001) and body weight (P < 0.0002). In men, total alcohol consumption was positively associated with waist-to-hip ratio (WHR, P < 0.0002) and waist girth (P < 0.004), independently of BMI. Similarly, in women, positive associations were found between alcohol intake and WHR (P < 0.0001) as well as waist girth (P < 0.0001), independently of BMI. In a linear regression model including types of beverages and usual confounders, reporting consumption of either wine, beer or spirit was poorly associated with WHR in men, whereas wine (P < 0.0008) and beer (P < 0.0001) consumptions were both positively associated with WHR in women. However, there was no evidence of a statistically significant heterogeneous effect of wine, beer and spirits on WHR in both genders.

CONCLUSION

In a sample of representative French people, in whom wine is the most common alcoholic beverage, alcohol consumption is associated with greater WHR independently of BMI in both men and women.

An orthotopic floor-of-mouth cancer model allows quantification of tumor invasion

OBJECTIVES

To establish an orthotopic murine floor-of-mouth cancer model for the analysis of the role of proteases such as urokinase-type plasminogen activator (u-PA) and the matrix metalloprotease MMP-9 (MMP-9) in in vivo invasion.

STUDY DESIGN

Randomized, prospective animal study.

METHODS

Two human squamous cell carcinoma cell lines, UM-SCC-1 and 022, were assayed via zymography for their in vitro secretion levels of u-PA and MMP-9. Both cell lines (5 x 10(6) cells) were injected into the cervical subcutaneous tissues of female athymic nude (nu/nu) mice superficial to the mylohyoid muscle. Mice were sacrificed after 30 days, and tumor invasion characteristics were histologically compared. Additional mice were then inoculated with invasive UM-SCC-1 cells and sacrificed 10, 30, and 40 days after inoculation to identify distinct stages of invasion.

RESULTS

In vitro secretion levels of MMP-9 and activity of u-PA were higher in UM-SCC-1 cells than in 022 cells. In the in vivo studies, tumors formed from 022 cells were found to be noninvasive, whereas tumors derived from UM-SCC-1 cells progressed through distinct and readily identifiable histologic stages of invasion. These stages included invasion of adjacent muscle layers (mylohyoid, geniohyoid, and genioglossus muscles) and of associated structures (blood vessels, bone, nerve, and regional lymph nodes). A staging system was devised accordingly.

CONCLUSION

We developed an in vivo quantitative cancer invasion model that allows determination of the effect of the expression and activity levels of the proteases MMP-9 and u-PA. Tumor invasion occurred in an orderly and stepwise fashion involving muscles and related vascular, nervous, and bony structures of the floor of the mouth and tongue. This orderly invasion allowed the development of a staging system. We anticipate that this model will have wide applicability in the study of in vivo tumor response to a variety of novel therapeutic approaches.

Dynamic heart rate variability: a tool for exploring sympathovagal balance continuously during sleep in men

We have recently demonstrated that the overnight profiles of cardiac interbeat autocorrelation coefficient of R-R intervals (rRR) calculated at 1-min intervals are related to the changes in sleep electroencephalographic (EEG) mean frequency, which reflect depth of sleep. Other quantitative measures of the Poincaré plots, i.e., the standard deviation of normal R-R intervals (SDNN) and the root mean square difference among successive R-R normal intervals (RMSSD), are commonly used to evaluate heart rate variability. The present study was designed to compare the nocturnal profiles of rRR, SDNN, and RMSSD with the R-R spectral power components: high-frequency (HF) power, reflecting parasympathetic activity; low-frequency (LF) power, reflecting a predominance of sympathetic activity with a parasympathetic component; and the LF-to-HF ratio (LF/HF), regarded as an index of sympathovagal balance. rRR, SDNN, RMSSD, and the spectral power components were calculated every 5 min during sleep in 15 healthy subjects. The overnight profiles of rRR and LF/HF showed coordinate variations with highly significant correlation coefficients (P < 0.001 in all subjects). SDNN correlated with LF power (P < 0.001), and RMSSD correlated with HF power (P < 0.001). The overnight profiles of rRR and EEG mean frequency were found to be closely related with highly cross-correlated coefficients (P < 0. 001). SDNN and EEG mean frequency were also highly cross correlated (P < 0.001 in all subjects but 1). No systematic relationship was found between RMSSD and EEG mean frequency. In conclusion, rRR appears to be a new tool for evaluating the dynamic beat-to-beat interval behavior and the sympathovagal balance continuously during sleep. This nonlinear method may provide new insight into autonomic disorders.

Isolation of Lautropia mirabilis from oral cavities of human immunodeficiency virus-infected children

Lautropia mirabilis, a pleomorphic, motile, gram-negative coccus, has been isolated from the oral cavities of 32 of 60 (53.3%) children infected with human immunodeficiency virus (HIV) and 3 of 25 (12.0%) HIV-uninfected controls; the association of L. mirabilis isolation with HIV infection is significant (P < 0.001). All children in the study, both HIV-infected children and controls, were born to HIV-infected mothers. The presence of this bacterium was not associated with clinical disease in these children. The HIV-infected children with L. mirabilis did not differ from the HIV-infected children without L. mirabilis in immunological status, clinical status, or systemic medications. The role of HIV infection itself or concomitant factors in the establishment of L. mirabilis in the oral cavity remains to be elucidated.

Circadian and ultradian variations of leptin in normal man under continuous enteral nutrition: relationship to sleep and body temperature

To determine the influence of circadian rhythmicity and sleep on the 24-h leptin diurnal variations, plasma leptin levels were measured at 10-min intervals over 24 h in seven normal subjects, once during nocturnal sleep, and once after an 8-h shift of sleep. The subjects were submitted to constant conditions (continuous enteral nutrition and bed rest in controlled chambers). Body temperature and plasma glucose and insulin levels were measured simultaneously. During nighttime sleep, leptin levels increased to a maximum (109.9 +/- 2.5% of the 24-h mean) and then decreased to reach a nadir in the late afternoon. The mean diurnal variation was 18.0 +/- 3.8% of the 24-h mean. In the daytime sleep condition, leptin levels rose during the night of deprivation to a maximum of 104.7 +/- 2.3% of the 24-h mean, decreased to a minimum around 0700 h, and then rose again during diurnal sleep (108.4 +/- 3.1% of the 24-h mean); the mean diurnal variation was 13.4 +/- 3.6% of the 24-h mean. ANOVA revealed a significant interaction between time of day and sleep effects (P < 0.05). The diurnal and the sleep-related variations of plasma leptin mirrored those of body temperature and roughly paralleled those of plasma glucose and insulin; the amplitudes of the diurnal leptin variations were significantly correlated with the amplitudes of the diurnal body temperature variations (P < 0.05). Plasma leptin levels also displayed irregular pulses of low amplitude (mean duration, 70 min) that were not affected by sleep, but were associated with a significant decrease in glucose and insulin levels (P < 0.01). These results demonstrate that under continuous enteral nutrition, plasma leptin levels are modulated by both a slight circadian component and sleep, which interact under normal conditions, and suggest that leptin is implicated in circadian thermoregulatory adjustments.

Circadian and ultradian variations of leptin in normal man under continuous enteral nutrition: relationship to sleep and body temperature

To determine the influence of circadian rhythmicity and sleep on the 24-h leptin diurnal variations, plasma leptin levels were measured at 10-min intervals over 24 h in seven normal subjects, once during nocturnal sleep, and once after an 8-h shift of sleep. The subjects were submitted to constant conditions (continuous enteral nutrition and bed rest in controlled chambers). Body temperature and plasma glucose and insulin levels were measured simultaneously. During nighttime sleep, leptin levels increased to a maximum (109.9 +/- 2.5% of the 24-h mean) and then decreased to reach a nadir in the late afternoon. The mean diurnal variation was 18.0 +/- 3.8% of the 24-h mean. In the daytime sleep condition, leptin levels rose during the night of deprivation to a maximum of 104.7 +/- 2.3% of the 24-h mean, decreased to a minimum around 0700 h, and then rose again during diurnal sleep (108.4 +/- 3.1% of the 24-h mean); the mean diurnal variation was 13.4 +/- 3.6% of the 24-h mean. ANOVA revealed a significant interaction between time of day and sleep effects (P < 0.05). The diurnal and the sleep-related variations of plasma leptin mirrored those of body temperature and roughly paralleled those of plasma glucose and insulin; the amplitudes of the diurnal leptin variations were significantly correlated with the amplitudes of the diurnal body temperature variations (P < 0.05). Plasma leptin levels also displayed irregular pulses of low amplitude (mean duration, 70 min) that were not affected by sleep, but were associated with a significant decrease in glucose and insulin levels (P < 0.01). These results demonstrate that under continuous enteral nutrition, plasma leptin levels are modulated by both a slight circadian component and sleep, which interact under normal conditions, and suggest that leptin is implicated in circadian thermoregulatory adjustments.

Breast cytology and biomarkers obtained by random fine needle aspiration: use in risk assessment and early chemoprevention trials

In a prospective pilot study, we performed breast fine needle aspirations (FNAs) on 224 high-risk and 30 low-risk women and analyzed these aspirates for cytologic changes and biomarker abnormalities of aneuploidy and overexpressed estrogen receptor (ER), epidermal growth factor receptor (EGFR), p53 and HER-2/neu. High-risk women had a first-degree relative with breast cancer (74%), prior biopsy indicating premalignant breast disease (25%), a history of breast cancer (13%), or some multiple of these risk factors (12%). Median ages of the high- and low-risk groups were 44 and 42, respectively. Seventy percent of high-risk and 17% of low-risk women had cytologic evidence of hyperplasia with or without atypia (P < .0001). Aneuploidy and overexpression of EGFR and p53 occurred in 27, 37, and 29% of high-risk subjects but only 0, 3, and 3% of low-risk subjects (P < .0023). Overexpression of ER and HER-2/neu occurred in 7 and 20% of high-risk women but in none of the low-risk subjects. Biomarker abnormalities were more frequent with increasing cytologic abnormality. Restricting the analysis to those 3 biomarkers most frequently overexpressed in the high-risk group (ploidy, EGFR, p53), 13% of high-risk women with normal cytology, 19% of high-risk women with epithelial hyperplasia, and 49% of high-risk women with hyperplasia with atypia had abnormalities of 2 or more of these 3 biomarkers (P = .00004). At a median follow-up of 32 months, four women have been diagnosed with invasive cancer and two with ductal carcinoma in situ (DCIS). Later detection of these neoplastic conditions was associated (P < or = .016) by univariate analysis with prior FNA evidence of hyperplasia with atypia; overexpression of p53 and EGFR; the modified Gail risk of breast cancer development at 10 years; and multiple biomarker abnormalities. By multivariate analysis, later detection of cancer was primarily predicted by the number of biomarker abnormalities in the 3-test battery (P = .0005) and secondarily by the Gail risk at 10 years (P = .0049). In turn, hyperplasia with atypia was associated with multiple biomarker abnormalities, particularly p53 and EGFR overexpression. Thus, hyperplasia with atypia and cytologic markers in breast FNAs have promise as risk predictors and as surrogate endpoint biomarkers for breast cancer chemoprevention trials.

[TIPSS: 10 years of clinical experience]

To demonstrate and document 10 years of clinical experience gathered by us with TIPSS and to discuss achievements, problems and outlook.

MATERIAL AND METHODS

The analysis is based on the following parameters: portosystemic gradient; morphological delineation of the portal circulation; determination of the portal perfusion fraction (PPF) and the total liver perfusion (GLP); arterial flow changes; hepatic encephalopathy; incidence of restenotic shunt occlusion and recurrent variceal bleeding.

RESULTS

Variceal filling was widely reduced by TIPSS, and significantly reduced portal liver perfusion as assessed morphologically and rheologically. However, there was an immediate onset of compensated liver perfusion by increased arterial inflow. Total liver perfusion did not change significantly. In TIPSS portal decompression was readily achieved, the portosystemic gradient dropping from an average of 24 mm Hg to 10.5 mm Hg. In our series we could not demonstrate an increased incidence of hepatic encephalopathy during the 30-day post-TIPSS period. Early mortality was 4% and early rebleeding rate 3%. The 12-month re-intervention rate based on an invasive portography follow-up protocol was 76%, and the 24-month re-intervention rate was 90%. The definite occlusion rate was below 5%. Beyond a follow-up time span of 24-months the necessity for re-intervention dropped significantly: less than one-third of our patients required some sort of re-intervention.

CONCLUSION

The concept of TIPSS represents an individually calibrated H-shunt. The significant reduction of post-TIPSS portal perfusion appears to be compensated by increased arterial inflow. This is reflected by an invasive flow measurement results and by the clinical results. Lethality of TIPSS is low mostly as a result of a refined technique, careful patient selection, follow-up care and meticulous shunt surveillance.

Expression of ARNT, ARNT2, HIF1 alpha, HIF2 alpha and Ah receptor mRNAs in the developing mouse

The basic helix-loop-helix-PAS (bHLH-PAS) protein ARNT is a dimeric partner of the Ah receptor (AHR) and hypoxia inducible factor 1 alpha(HIF1 alpha). These dimers mediate biological responses to xenobiotic exposure and low oxygen tension. The recent cloning of ARNT and HIF1(homologues (ARNT2 and HIF2 alpha) indicates that at least six distinct bHLH-PAS heterodimeric combinations can occur in response to a number of environmental stimuli. In an effort to understand the biological relevance of this combinatorial complexity, we characterized their relative expression at a number of developmental time points by parallel in situ hybridization of adjacent tissue sections. Our results reveal that in general there is limited redundancy in the expression of these six transcription factors and that each of these bHLH-PAS members displays a unique pattern of developmental expression emerging as early as embryonic day 9.5.

Inhibition of the p38 mitogen-activated protein kinase by SB 203580 blocks PMA-induced Mr 92,000 type IV collagenase secretion and in vitro invasion

Although the p38 mitogen-activated protein kinase (MAPK) has been implicated in signal transduction events, its role in regulating the Mr 92,000 type IV collagenase matrix metalloprotease-9 (MMP-9) and in vitro invasiveness in cancer has not yet been determined. We made the surprising observation that, in a human squamous cell carcinoma cell line (UM-SCC-1), phorbol ester-enhanced MMP-9 secretion and in vitro invasiveness were associated with a strong activation of the p38 MAPK and its downstream target, MAPK-activated protein kinase-2. To determine the role of p38 activation in these events, we investigated the effect of SB 203580, a novel specific p38 inhibitor, on protease expression and in vitro invasion of these cells. We found that inhibition of p38 by SB 203580 resulted in the almost complete reduction of phorbol myristate acetate-induced MMP-9 secretion but not of urokinase-type plasminogen activator secretion. In contrast, the activation of a transiently transfected wild-type MMP-9 promoter by MEKK-1, a specific c-Jun NH2-terminal kinase activator, was only marginally inhibited by the compound, arguing for the specificity of SB 203580. Moreover, phorbol myristate acetate-enhanced in vitro invasion was completely blocked by SB 203580, whereas p38 inhibition had little effect on growth. These findings suggest that activation of p38 may contribute to a more invasive phenotype in vitro, possibly via the expression of MMP-9, and that targeting of p38 using SB 203580 may provide a novel means of controlling invasion of cancers in which this MAPK is activated.

A pilot study of combination therapy with indinavir, stavudine (d4T), and didanosine (ddI) in children infected with the human immunodeficiency virus

Twelve children infected with the human immunodeficiency virus were treated orally with indinavir, stavudine, plus didanosine for 12 to 48 weeks. Therapy was limited in some cases by nonadherence, intolerance, toxicity, and virologic failure. Marked increases in CD4+ lymphocyte counts and decreases in plasma human immunodeficiency virus RNA concentrations suggest that the regimen has potent antiviral activity.

[Follow-up of albumin excretion during pregnancy and post partum in type 1 diabetic patients in comparison with health pregnant probands]

32 diabetic and 31 metabolic healthy pregnant women are studied to answer the following questions: Is there a difference in the albumin-excretion rate (AER) during the pregnancy in primary normoalbuminuric type 1 diabetics and non-diabetics? Is there a difference 6 months post partum between the 2 groups? The average age of the diabetics (D) is 28, of the non-diabetics (ND) 27 years; the diabetics suffer from diabetes mellitus 12.5 years. In the 16th week of pregnancy, we find a AER (D vs. ND) of 5.0 vs. 2.37 micrograms/min (not significant [n.s.]), creatinin in serum 0.77 vs. 0.75 mg/dl (p < 0.05), creatinin clearance 92.5 vs. 103.4 ml/min (n.s.). In the 28th and in the 34th to 38th week, there is no significant elevation of the AER compared to the 16th week; but there is a significant elevation in the diabetics vs. the non-diabetics. 6 months post partum, the AER (D vs. ND) are: 6.13 vs. 5.11 micrograms/min (n.s. vs. 16th week and D vs. ND); in each group one person is found with a positive microalbuminuria (MA): 48.2 micrograms/min (D) and 27.4 mg/min (ND). Another diabetic woman shows post partum an isolated higher value of creatinin in serum: 1.5 mg/dl (without MA). This parameter is post partum significant higher (0.97 [D], 0.96 [ND] mg/dl) than in the 16th week of pregnancy (0.77 [D], 0.75 [ND] mg/dl). The creatinin clearance decreases post partum (pp): 92.2 ml/min (pp) vs. 102.0 ml/min (28th week) in the diabetics (n.s.) and 80.6 ml/min (pp) vs. 111.0 ml/min (28th week) in the non-diabetics (p < 0.05). Concerning the studied renal parameters, there is a significant difference of the albumin-excretion rates during the pregnancy between preconceptional normoalbuminuric type 1 diabetic and non-diabetic women, but 6 months post partum, there is no significant difference. The diabetics show a significant increase of the creatinin in urine and in serum and no significant change of the creatinin clearance 6 months post partum.

[Lipoma of the internal auditory canal. Report of two cases simulating acoustic neuroma]

We report two cases of intra-auditory canal lipoma, presenting as acoustic neuroma, observed in respectively 45 and 53 year old patients. Cerebellopontine angle lipomas are unusual lesions, more exceptional than their intracranial counter-parts. The knowledge of these tumoral lesions and of their close relationships with cranial nerves incite to perform a frozen section when imagery is evocative, to limit functional postoperative sequelae.

Two-dimensional temperature estimation using diagnostic ultrasound

A two-dimensional temperature estimation method was developed based on the detection of shifts in echo location of backscattered ultrasound from a region of tissue undergoing thermal therapy. The echo shifts are due to the combination of the local temperature dependence of speed of sound and thermal expansion in the heated region. A linear relationship between these shifts and the underlying tissue temperature rise is derived from first principles and experimentally validated. The echo shifts are estimated from the correlation of successive backscattered ultrasound frames, and the axial derivative of the accumulated echo shifts is shown to be proportional to the temperature rise. Sharp lateral gradients in the temperature distribution introduce ripple on the estimates of the echo shifts due to a thermo-acoustic lens effect. This ripple can be effectively reduced by filtering the echo shifts along the axial and lateral directions upon differentiation. However, this is achieved at the expense of spatial resolution. Experimental evaluation of the accuracy (0.5 degrees C) and spatial resolution (2 mm) of the algorithm in tissue mimicking phantoms was conducted using a diagnostic ultrasound imaging scanner and a therapeutic ultrasound unit. The estimated temperature maps were overlaid on the gray-scale ultrasound images to illustrate the applicability of this technique for image guidance of focused ultrasound thermal therapy.

Terlipressin may influence the outcome of hepatorenal syndrome complicating alcoholic hepatitis

Hepatorenal syndrome is a frequent complication associated with extremely short survival in cirrhotic patients with alcoholic hepatitis. Vasopressin analogs have been reported to induce transient regression of hepatorenal syndrome in patients with cirrhosis. However, treatment withdrawal was followed by early recurrences in every case. We report the case of a 68-yr-old woman with severe alcoholic hepatitis complicated by hepatorenal syndrome. Terlipressin induced a prolonged recovery of renal function that was associated with improvement in hepatic function.

Cervical lymph node metastasis from an unknown primary: is a tonsillectomy necessary?

PURPOSE

The detection of an infraclinical primary by tonsillectomy in case of cervical lymph node of an epidermoid carcinoma with unknown primary after a radical neck dissection, allows avoiding irradiation of the normal larynx. The aim of this study is to quantify the rate of tonsil primary to justify this procedure.

METHODS AND MATERIALS

From 1969 to 1992, 87 patients had a tonsillectomy as part of the workup for cervical nodal metastasis of an epidermoid carcinoma with unknown primary. The mean age was 57 years (range: 39-75 years) and the sex ratio was 8.6. Sixty-seven patients had a single cervical adenopathy (17 N1, 30 N2a, 5 N3, 15 Nx), and 20 patients multiple cervical adenopathies (17 N2b, 3 N2c). The treatments included always an irradiation to the node areas (50 Gy), and to the pharyngolarynx in case of normal tonsil (50 Gy), or to the tonsil if it was the primary (50 Gy with a brachytherapy boost of 20-25 Gy). In this last case, the larynx could be protected.

RESULTS

Tonsillectomy never induced specific complication. Out of 87 patients, 26% had a tonsil primary. There was not specific histological differentiation in this group. In the 67 patients with a single cervical adenopathy, 31% had a tonsil primary (6 N1, 7 N2, 1 N3, 7 Nx). It was a subdigastric adenopathy in 38%, a submandibular in 28% and a midjugulocarotidian in 23%. Among the 17 patients N2b, none had a tonsil primary. In the three patients N2c, two presented a tonsil carcinoma (two subdigastric nodes).

CONCLUSION

Tonsillectomy allows avoiding irradiation of normal larynx in 26% of patients who have a cervical lymph node with unknown primary. It should be performed in case of a single node of the subdigastric, midjugulocarotidian or submandibular area or bilateral subdigastric adenopathies.

Temporal relationship between dynamic heart rate variability and electroencephalographic activity during sleep in man

In previous sleep studies, it has been demonstrated that Poincare plots of RR intervals, which provide a beat to beat dynamic measure of heart rate variability, have distinctive and characteristic patterns according to sleep stages. This study was designed to evaluate the temporal relationship between heart rate variability and sleep electroencephalographic activity (EEG) by using the Pearson's interbeat autocorrelation coefficients of RR intervals derived from the Poincare plots. The coefficients were calculated in 12 subjects over each minute and were related to the profiles of EEG mean frequency (0.5-35 Hz) computed using a Fast Fourier Transformation algorithm. Overnight profiles of interbeat autocorrelation coefficients and of EEG mean frequency were found to be related with highly significant cross-correlation coefficients ranging between 0.216 and 0.638 (P < 0.001). The variations in heart rate variability preceded changes in brain activity by 1-2 min. These results demonstrate that beat to beat heart rate variability and EEG activity are closely linked during sleep in normal man.

Post-operative brachytherapy: a prognostic factor for local control in epidermoid carcinomas of the mouth floor

The aim of this study was to analyse the role of post-operative brachytherapy (BT) in a group of patients with a high risk of local relapse (positive or narrow surgical margins) for squamous cell carcinoma of the mouth floor (SCCFM). A comparison with post-operative external beam irradiation (EBI) in a group of patients with standard risk of local relapse for SCCFM with free margins is performed to estimate the benefit of BT. From 1979 to 1992, an initial group of 32 patients with SCCFM (12, T1-2; 20, T3-4x) received an Ir 192 low dose rate BT using plastic tubes (+EBI for 20 patients) after surgery with positive or close margins. BT was applied in one or two planes to the surgical scar. The mean dose of BT was 57 Gy (range: 50-60) for exclusive BT and 22 Gy (range: 15-30) when a boost was applied (mean EBI dose = 50 Gy). During the same period, 36 patients had post-operative external irradiation alone after satisfactory surgical resection. Excluding the post-operative margin, these two groups were comparable for other prognostic factors. The mean follow-up was 46 months (range: 5-145) with a minimum follow-up of 2 years. For BT and EBI groups, the 5-year results (Kaplan-Meier) were, respectively, overall survival 62% and 43%, local control 81% and 60% (P = 0.09) (log-rank) and severe complications 4/32 and 1/36. Post-operative BT achieves good local control for patients with narrow or positive margins by increasing the dose to the surgical scar, with good tolerance. Given these encouraging results, we confirm this treatment for these patients.

Elevated urokinase-type plasminogen activator receptor expression in a colon cancer cell line is due to a constitutively activated extracellular signal-regulated kinase-1-dependent signaling cascade

The urokinase-type plasminogen activator receptor (u-PAR) facilitates extracellular matrix degradation in part by accelerating plasmin formation at the cell surface. We previously reported that u-PAR expression is elevated in colon cancer cell lines characterized by their in vitro invasive capacity. Since, u-PAR expression is increased by a variety of growth factors, which signal through the extracellular signal-regulated kinases 1 and 2 (ERK1/ERK2), we determined if these mitogen-activated protein kinases (MAPKs) regulate u-PAR expression in two cultured colon cancer cell lines. An in-gel kinase assay showed that ERK1 activity was considerably higher in RKO cells, which display > or = 10(5) receptors/cell, than the GEO cells which have approximately 10(4) urokinase receptors per cell. The expression of either an ERK-inactivating phosphatase (CL100), or a kinase-defective ERK1, decreased the activity of a u-PAR promoter-driven CAT reporter in RKO cells. Immune complex kinase assays indicated that the constitutive ERK1 activity in RKO cells was largely a result of an activated MEK1. Further, treatment of RKO cells with a specific inhibitor (PD 098059) of MEK1 activation, which diminished ERK1 activity, reduced the amount of urokinase specifically bound to the cell surface and this was associated with reduced laminin degradation. The expression of a dominant negative c-Raf-1 also reduced u-PAR promoter activity suggesting that MEK1 activation involved an activator at, or upstream, of this serine-threonine kinase. Transfection of the u-PAR-deficient GEO cells with a constitutively activated MEK1 expression construct up-regulated u-PAR promoter activity. Similarly treatment of GEO cells with a phosphatase inhibitor (sodium vanadate) caused a dose-dependent increase in ERK1 activity which paralleled increased cell surface binding of urokinase. Taken together, these data suggest that elevated u-PAR expression, in at least a sub-population of colon cancer, is partly a consequence of a constitutively activated ERK-1-dependent signaling cascade.