A simple method for assessing the validity of the esophageal balloon technique

The validity of the conventional esophageal balloon technique as a measure of pleural pressure was tested in 10 subjects in sitting, supine, and lateral positions by occluding the airways at end-expiration and measuring the ratio of changes in esophageal (delta Pes) and mouth pressure (delta Pm) during the ensuing spontaneous occluded inspiratory efforts. Similar measurements were also made during static Mueller maneuvers. In both tests, delta Pes/delta Pm values were close to unity in sitting and lateral positions, whereas in the supine position, substantial deviations from unity were found in some instances. However, by repositioning the balloon to different levels in the esophagus, even in these instances a locus could be found where the delta Pes/delta Pm ratio was close to unity. No appreciable phase difference between delta Pes and delta Pm was found. We conclude that by positioning the balloon according to the "occlusion test" procedure, valid measurements of pleural pressure can be obtained in all the tested body positions.

Idiopathic epiretinal membranes. Ultrastructural characteristics and clinicopathologic correlation

Current theories of idiopathic epiretinal membrane (ERM) pathogenesis, based mainly on clinical and autopsy studies, emphasize a glial tissue origin. The clinical and ultrastructural features of 101 cases of idiopathic ERMs removed from the macular area during vitrectomy were studied. The predominant cell type was retinal pigment epithelium (RPE) in 51 cases, fibrous astrocytes in 29 cases, fibrocytes in 14 cases, and myofibroblasts in 7 cases. Features of myofibroblastic differentiation were present in 64 cases. Myofibrocytes were more common in younger patients with shorter duration of symptoms. Fibrous astrocytes were more common in females. The high incidence of RPE cells in this series raises new questions regarding the pathogenesis of idiopathic ERMs.

Brain tissue oxygen guided treatment supplementing ICP/CPP therapy after traumatic brain injury

OBJECTIVE

To evaluate the effects of a brain tissue oxygen (P(ti)O(2)) guided treatment in patients with traumatic brain injury.

METHODS

P(ti)O(2) was monitored in 93 patients with severe traumatic brain injury. Forty patients admitted from 1993 to 1996 were treated with intracranial pressure/cerebral perfusion pressure (ICP/CPP) management alone (ICP < 20 mm Hg, CPP > 70 mm Hg). Fifty three patients admitted from 1997 to 2000 were treated using ICP/CPP management, but in this second group CPP was also increased as individually required to raise the P(ti)O(2) above 1.33 kPa (10 mm Hg) (P(ti)O(2) guided group).

RESULTS

Cerebral hypoxic phases with P(ti)O(2) values below 1.33 kPa occurred significantly less often in the P(ti)O(2) guided group. P(ti)O(2) values were higher over the whole monitoring period. No statistical differences could be observed in outcome at six months, despite a positive trend in the P(ti)O(2) guided group.

CONCLUSIONS

Cerebral hypoxic events can be reduced significantly by increasing cerebral perfusion pressure as required. To show a clear beneficial effect of P(ti)O(2) guided cerebral perfusion pressure management on outcome, a multicentre randomised trial needs to be undertaken.

Correlation of continuously monitored regional cerebral blood flow and brain tissue oxygen

BACKGROUND

The purpose of this study was to investigate the relationship between continuously monitored regional cerebral blood flow (CBF) and brain tissue oxygen (PtiO2).

METHODS

Continuous advanced multimodal neuromonitoring including monitoring of PtiO2 (Licox, GMS) and CBF (QFlow, Hemedex) was performed in eight patients after severe subarachnoid haemorrhage (n=5) and traumatic brain injury (n=3) for an average of 9.6 days. Parameters were measured using a flexible polarographic PtiO2-probe and a thermal diffusion CBF-microprobe.

FINDINGS

Regarding the whole monitoring period in all patients, the data indicated a significant correlation between CBF and PtiO2 (r=0.36). In 72% of 400 analysed intervals of 30 minutes duration with PtiO2 changes larger than 5 mmHg, a strong correlation between CBF and PtiO2 existed (r>0.6). In 19% of intervals a still statistically significant correlation was observed (0.3<r<0.6). During the remaining 9% no correlation was found (r<0.3). Regarding the clinical stability of the monitoring devices, the CBF monitoring system allowed monitoring of CBF in 64% of the time when PtiO2 monitoring was possible only. Phases of non-monitoring were mostly due to fever of the patient, when the system does not allow monitoring to avoid overheating of the cerebral tissue.

CONCLUSIONS

This study suggests a correlation between CBF and PtiO2. The level of PtiO2 seems to be predominately determined by regional CBF, since changes in PtiO2 were correlated in 90% of episodes to simultaneous changes of CBF.

Effects of decompressive craniectomy on brain tissue oxygen in patients with intracranial hypertension

This report examined the intraoperative course of partial pressure of brain tissue oxygen (P(ti)O(2)) and intracranial pressure (ICP) during surgical decompressive craniectomy for medically intractable intracranial hypertension due to diffuse brain swelling in three patients after severe subarachnoid haemorrhage and aneurysm coiling. The mean ICP decreased from 59 mm Hg to 10 mm Hg in a two step fashion, relating to bone flap removal and dural opening. Simultaneously, P(ti)O(2) increased rapidly from 0.8 kPa (6 mm Hg) to 3.07 kPa (23 mm Hg). P(ti)O(2) and ICP remained at non-critical ranges postoperatively. Despite these beneficial effects on ICP and P(ti)O(2), the patients' clinical status remained poor with two in a persistent vegetative state and one dead.

Is hyperhomocysteinemia due to the oxidative depletion of folate rather than to insufficient dietary intake?

Hyperhomocysteinemia is considered as a risk factor for cardiovascular diseases. Usually, an inverse relationship exists between homocysteine and folate levels, and supplementation with folate lowers homocysteine concentrations in patients. Therefore, hyperhomocysteinemia is mainly ascribed to the insufficient dietary intake of folate. Hyperhomocysteinemia has also been observed in infections and inflammatory diseases. Oxidative stress appears to be involved in the pathogenesis of these disorders, and associations have been found between homocysteine and e.g., neopterin concentration. Increased neopterin concentration indicates immune system activation and also allows an estimate of thus elicited oxidative stress. It may be relevant that the active cofactor, tetrahydrofolate, is very susceptible to oxidation. Immunologically induced oxidative stress could lead to folate depletion resulting in hyperhomocysteinemia. Thus, hyperhomocysteinemia in patients can be considered as an indirect consequence of hyperconsumption of antioxidant vitamins during prolonged states of immune activation.

Prognostic factors in nonoperative therapy for chronic symptomatic calcific tendinitis of the shoulder

OBJECTIVE

To define prognostic factors in chronically symptomatic patients with calcific tendinitis of the shoulder.

METHODS

We evaluated 420 patients (488 shoulders) in the context of a prospective cohort study. Epidemiologic data were assessed. The radiographic and sonographic appearance of the calcific deposits was classified. The mean period of nonoperative therapy was 4.4 years (range 0.5-13.7 years). After referral to our institution, standardized nonoperative therapy was continued for a minimum of 3 months. Failure of nonoperative therapy was defined as the persistence of symptomatic calcific tendinitis of the shoulder after a minimum of 6 months. Prognostic factors (determined at P < 0.05 by chi-square test) were analyzed by logistic regression.

RESULTS

Of the 420 patients, 269 (64%) were women, 151 (36%) were men. The mean age of the patients was 51.3 years (range 28-84 years). Occurrence of calcific tendinitis of the shoulder was unilateral in 84% and bilateral in 16%. Gärtner type I calcific deposits were found in 37%, type II in 32%, and type III in 31%. Failure of nonoperative therapy was observed in 114 patients (27%). Negative prognostic factors were bilateral occurrence of calcific tendinitis of the shoulder, localization to the anterior portion of the acromion, medial (subacromial) extension, and high volume of the calcific deposit. Positive prognostic factors were a Gärtner type III deposit and a lack of sonographic sound extinction of the calcific deposit.

CONCLUSION

Our findings demonstrate the existence of prognostic factors in the nonoperative treatment of chronic symptomatic calcific tendinitis of the shoulder. Guidelines for optimal treatment can be implemented according to these factors to avoid a long-term symptomatic disease course.

A double-blind trial of synthetic salmon calcitonin in the treatment of acute pancreatitis

A multicenter randomized double-blind trial on the use of synthetic salmon calcitonin (SCT) was carried out in 94 patients with acute pancreatitis. In addition to strict standard treatment--without aprotinin, atropine, or antacids--50 patients received daily 3 x 20 micrograms = 300 MRCU SCT intravenously and 44 patients received placebo for 6 days. Mortality rate was not influenced, overall mortality being 5.3%. The number of patients without pain and with normalized serum amylase on a given day was significantly higher in the group treated with SCT. Other parameters such as doses of analgesics, leukocyte count, and normalization of seven defined clinical and laboratory criteria within 6 days showed a positive trend without reaching significance.

Pattern recognition pathways leading to a Th2 cytokine bias in allergic bronchopulmonary aspergillosis patients

BACKGROUND

Allergic bronchopulmonary aspergillosis (ABPA) is characterised by an exaggerated Th2 response to Aspergillus fumigatus, but the immunological pathways responsible for this effect are unknown.

OBJECTIVE

The aim of this study was to decipher the pattern recognition receptors (PRRs) and cytokines involved in the Aspergillus-specific Th2 response and to study Aspergillus-induced responses in healthy controls and ABPA patients.

METHODS

Peripheral blood mononuclear cells (PBMCs) were stimulated with heat-killed Aspergillus conidia, various other pathogens, or PRR ligands. PRRs and cytokine pathways were blocked with PRR-blocking reagents, anti-TNF (Etanercept or Adalimumab), IL-1Ra (Anakinra) or IFNγ (IFN-gamma). ELISA and FACS were used to analyse cytokine responses.

RESULTS

Aspergillus was the only pathogen that stimulated the Th2 cytokines IL-5 and IL-13, while Gram-negative bacteria, Gram-positive bacteria, Candida albicans, chitin, β-glucan or Toll-like receptor (TLR) ligands did not. Depletion of CD4(+) cells abolished IL-13 production. Blocking complement receptor 3 (CR3) significantly reduced IL-5 and IL-13, while blocking TLR2, TLR4 or dectin-1 had no effect. ABPA patients displayed increased Aspergillus-induced IL-5 and IL-13 and decreased IFNγ production compared with healthy controls. All biological agents tested showed the capability to inhibit Th2 responses, but also decreased Aspergillus-induced IFNγ.

CONCLUSIONS AND CLINICAL RELEVANCE

Aspergillus conidia are unique in triggering Th2 responses in human PBMCs, through a CR3-dependent pathway. ABPA patients display a significantly increased Aspergillus-induced Th2/Th1 ratio that can be modulated by biologicals. These data provide a rationale to explore IFNγ therapy in ABPA as a corticosteroid-sparing treatment option, by dampening Th2 responses and supplementing the IFNγ deficiency at the same time.

The impact of interindividual variation in NAT2 activity on benzidine urinary metabolites and urothelial DNA adducts in exposed workers

Several epidemiologic studies indicate that NAT2-related slow N-acetylation increases bladder cancer risk among workers exposed to aromatic amines, presumably because N-acetylation is important for the detoxification of these compounds. Previously, we showed that NAT2 polymorphisms did not influence bladder cancer risk among Chinese workers exposed exclusively to benzidine (BZ), suggesting that NAT2 N-acetylation is not a critical detoxifying pathway for this aromatic amine. To evaluate the biologic plausibility of this finding, we carried out a cross-sectional study of 33 workers exposed to BZ and 15 unexposed controls in Ahmedabad, India, to evaluate the presence of BZ-related DNA adducts in exfoliated urothelial cells, the excretion pattern of BZ metabolites, and the impact of NAT2 activity on these outcomes. Four DNA adducts were significantly elevated in exposed workers compared to controls; of these, the predominant adduct cochromatographed with a synthetic N-(3'- phosphodeoxyguanosin-8-yl)-N'-acetylbenzidine standard and was the only adduct that was significantly associated with total BZ urinary metabolites (r = 0.68, P < 0.0001). To our knowledge this is the first report to show that BZ forms DNA adducts in exfoliated urothelial cells of exposed humans and that the predominant adduct formed is N-acetylated, supporting the concept that monofunctional acetylation is an activation, rather than a detoxification, step for BZ. However, because almost all BZ-related metabolites measured in the urine of exposed workers were acetylated among slow, as well as rapid, acetylators (mean +/- SD 95 +/- 1.9% vs. 97 +/- 1.6%, respectively) and NAT2 activity did not affect the levels of any DNA adduct measured, it is unlikely that interindividual variation in NAT2 function is relevant for BZ-associated bladder carcinogenesis.

A Visual Representation and the Control of Manual Aiming Movements

Three experiments were conducted to determine if a representation of the movement environment is functional in the organization and control of limb movements, when direct visual contact with the environment is prevented. In Experiment 1, a visual rearrangement procedure was employed to show that a representation of the environment that provides inaccurate information about the spatial location of a target can disrupt manual target aiming. In Experiment 2, we demonstrated that spatial information about the position of a target can be destroyed by a visual pattern mask, supporting our claim that the representation is visual. A target-cuing procedure was used in Experiment 3 to show that representation of target position can be useful for premovement organization in a target-aiming task. Together our findings suggest that a short-lived visual representation of the movement environment may serve a useful role in the organization and control of limb movements.

Combined action of the ACE D- and the G-protein beta3 T-allele in major depression: a possible link to cardiovascular disease?

Although it is well established that depression is a major risk factor for the development of coronary artery disease and that cerebrovascular disease can be a major contributing factor for the development of depression, the information about the interplay between the central nervous system and cardiovascular disease is still limited. We investigated the angiotensin I converting enzyme (ACE) ID and the G-protein beta3-subunit (Gbeta3) C825T polymorphism in 201 patients with unipolar major depression and 161 ethnically and age-matched controls. Both gene variants have earlier been associated with either cardiovascular disease or affective disorders, making them good candidates for a combined analysis. We found a significant increase in the Gbeta3 T allele (OR = 1.61, 95% CI 1.17-2.2, P = 0.0035) and a marginal altered genotype distribution of the ACE ID polymorphism with decrease in the II genotypes (chi(2) = 6.43, df=3, P = 0.04) in the patients' group. Analysing the data for both genes we found that the combined actions of ACE and Gbeta3 genotypes accumulate in carriers of the ACE D allele (ID and DD) and Gbeta3 TT homozygotes with ID/DD-TT carriers showing a more than five-fold increase in risk for major depression (crude OR = 5.83, 95% CI 1.99-17.08, P = 0.0002). As our study was carried out with depressive patients without serious cardiac impairment at the time of the investigation, we are presently unable to predict whether this combined action of the ACE ID/DD-Gbeta3 TT genotype is increasing the risk for both disorders. Nevertheless our study reports for the first time that the same allelic combination of two genes that have been shown to increase the risk for myocardial infarction (Naber et al, 2000) increase the vulnerability for depressive disorder.

Association of a variable number tandem repeat in the NLRP3 gene in women with susceptibility to RVVC

Vaginal infections with Candida spp. frequently occur in women of childbearing age. A small proportion of these women experience recurrent vulvovaginal candidosis (RVVC), which is characterized by at least three episodes of infection in one year. In addition to known risk factors such as antibiotics, diabetes, or pregnancy, host genetic variation and inflammatory pathways such as the IL-1/Th17 axis have been reported to play a substantial role in the pathogenesis of RVVC. In this study, we assessed a variable number tandem repeat (VNTR) polymorphism in the NLRP3 gene that encodes a component of the inflammasome, processing the proinflammatory cytokines IL-1β and IL-18. A total of 270 RVVC patients and 583 healthy controls were analyzed, and increased diseases susceptibility was associated with the presence of the 12/9 genotype. Furthermore, functional studies demonstrate that IL-1β production at the vaginal surface is higher in RVVC patients bearing the 12/9 genotype compared to controls, whereas IL-1Ra levels were decreased and IL-18 levels remained unchanged. These findings suggest that IL-1β-mediated hyperinflammation conveyed by the NLRP3 gene plays a causal role in the pathogenesis of RVVC and may identify this pathway as a potential therapeutic target in the disease.

Structural elements common to mitosis and apoptosis

Both mitotic and apoptotic cells display hypercondensation of the chromatin and loss of the nuclear envelope (Lazebnik et al., 1993). Herein, we describe a third similarity between the two processes. We have observed, initially in apoptotic cells of the PC-12 lineage clusters of 40-60 (approximately 50) nm vesicles adjoined by a minor contingent of tubule vesicular elements of 100-200 nm which are indistinguishable from their vesicular counterparts in mitotic PC-12 cells. The clusters of approximately 50 nm vesicles were subsequently observed in all studied rat tissue cells in apoptosis (plasma cells and macrophages, secretory epithelial cells from pancreatic acini, ventral lobe of prostate and mammary gland). Clusters of approximately 50 nm vesicles comparable to those of the PC-12 cells were found in HeLa cells treated with human alfa TNF, in WEHI-3 cells exposed to VM 26 (a teneposide) (Sesso et al., 1997) and in HL-60 cells treated with thapsigargin. PC-12 and HeLa cells affixed to coverslips were double labelled and examined with the fluorescence microscope to reveal simultaneously the disposition of the chromatin with Hoechst stain and the distribution of the fluorescence of Golgi or of Golgi-associated proteins. A common pattern of fluorescence was observed in a minor proportion of apoptotic cells using three different antibodies used. The label frequently appeared as finely dispersed granules in the cytoplasm. In some apoptotic cells, relatively coarse granules were observed. This pattern of label distribution is compatible with the disposition of vesicular clusters we have encountered in apoptotic PC-12 cells sectioned serially or semi serially. In such sections of both mitotic and apoptotic PC-12 cells, we noticed that the conglomerates of 50 nm vesicles were frequently associated with cisternae of the rough ER. Vesicles of similar size were also noted pinching off from the extremities of Golgi cisternae reduced in size. These cisternae diminish in length and width when they are in the process of disassembling at the very beginning of mitosis and in apoptosis.

Characterization of the cellular component of polymorphous low-grade adenocarcinoma by immunohistochemistry and electron microscopy

In order to characterize the cellular component of the polymorphous low-grade adenocarcinoma (PLGA) of the salivary gland, a morphological and immunohistochemical study was carried out. Thirty cases of PLGA were studied by light microscopy and immunohistochemistry and five cases by transmission electron microscopy (TEM). The expression of cytokeratins (CKs) 7,8,10,13,14,18,19, vimentin and muscle-specific actin (MSA) was investigated through the streptavidin-biotin method. The majority of tumor cells stained for vimentin, CKs 8, 18 and 7. CK 14 was positive in most cells of the papillary and trabecular sub-types. Although the expression of CKs 8,18 and 14 varied among the tumors sub-types, a straight relationship between each histologic pattern and the CK expression could not be delineated. MSA was reactive in only three tumors while CKs 10 and 13 were not detected in any tumor studied. The absence of MSA and the expression of CKs 8,18 and 7, in most of the tumor cells, lead to the hypothesis that myoepithelial cells are not the major cellular component of the PLGA. TEM revealed cells exhibiting microvilli and variable amounts of secretory granules, some of them suggesting an excretory activity. The presence of CKs 8,18 and 7, added to the secretory granules, indicates that PLGA originates from cells located at the acinar-intercalated duct junction.

Improvement of brain tissue oxygen and intracranial pressure during and after surgical decompression for diffuse brain oedema and space occupying infarction

BACKGROUND

We evaluated the perioperative and intraoperative changes of intracranial pressure (ICP) and partial pressure of brain tissue oxygen (PtiO2) after decompressive craniectomy in patients with diffuse brain oedema and space occupying infarction.

METHODS

Ten patients suffering from medically intractable raised intracranial pressure (ICP) were included. The underlying diseases and causes for elevated ICP were diffuse brain oedema after subarachnoid haemorrhage (n = 3) and head injury (n = 3), or space occupying infarction of the middle cerebral artery territory due to vasospasm after SAH (n = 4). Continuous perioperative and intraoperative monitoring of PtiO2 and ICP was performed at the side of decompression.

FINDINGS

ICP and PtiO2 improved significantly in a uniform pattern during bone flap removal and dura opening, irrespective of the underlying disease (mean ICP from 52 mmHg to 8 mmHg, mean PtiO2 from 9 mmHg to 25 mmHg). ICP, PtiO2, and cerebral perfusion pressure were further improved in the subsequent 12 hours after surgery, as compared to the preoperative 12 hours.

CONCLUSIONS

Decompressive craniectomy seems to be a successful option in the treatment of intractable intracranial hypertension with associated cerebral hypoxia. These positive effects may last for several hours after the procedure irrespective of the underlying disease.

Vapor bubble generation around gold nano-particles and its application to damaging of cells

We investigated vapor bubbles generated upon irradiation of gold nanoparticles with nanosecond laser pulses. Bubble formation was studied both with optical and acoustic means on supported single gold nanoparticles and single nanoparticles in suspension. Formation thresholds determined at different wavelengths indicate a bubble formation efficiency increasing with the irradiation wavelength. Vapor bubble generation in Bac-1 cells containing accumulations of the same particles was also investigated at different wavelengths. Similarly, they showed an increasing cell damage efficiency for longer wavelengths. Vapor bubbles generated by single laser pulses were about half the cell size when inducing acute damage.

Chronic, topical exposure to benzo[a]pyrene induces relatively high steady-state levels of DNA adducts in target tissues and alters kinetics of adduct loss

Carcinogen-DNA adduct measurements may become useful biomarkers of effective dose and/or early effect. However, validation of this biomarker is required at several levels to ensure that human exposure and response are accurately reflected. Important in this regard is an understanding of the relative biomarker levels in target and nontarget organs and the response of the biomarker under the chronic, low-dose conditions to which humans are exposed. We studied the differences between single and chronic topical application of benzo[a]pyrene (BAP) on the accumulation and removal of BAP-DNA adducts in skin, lung, and liver. Animals were treated with BAP at 10, 25, or 50 nMol topically once or twice per week for as long as 15 weeks. Animals were sacrificed either at 24, 48, or 72 hr after the last dose at 1 and 30 treatments, and after 24 hr for all other treatment groups. Adduct levels increased with increasing dose, but the slope of the dose-response was different in each organ. At low doses, accumulation was linear in skin and lung, but at high doses the adduct levels in the lung increased dramatically at the same time when the levels in the skin reached apparent steady state. In the liver adduct, levels were lower than in target tissues and apparent steady-state adduct levels were reached rapidly, the maxima being independent of dose, suggesting that activating metabolism was saturated in this organ. Removal of adducts from skin, the target organ, was more rapid following single treatment than with chronic exposure. This finding is consistent with earlier data, indicating that some areas of the genome are more resistant to repair. Thus, repeated exposure and repair cycles would be more likely to cause an increase in the proportion of carcinogen-DNA adducts in repair-resistant areas of the genome. These findings indicate that single-dose experiments may underestimate the potential for carcinogenicity for compounds that follow this pattern.

Sacral insufficiency fracture, an unsuspected cause of low-back pain in elderly women

Sacral insufficiency fractures (SIF) usually occur in elderly women and are secondary to various conditions, mainly postmenopausal or steroid-induced osteoporosis and radiation therapy. They are often overlooked or confused clinically and radiographically with metastatic disease. We report a case of a 72-year-old woman who presented to our department with severe low-back pain. She was thoroughly investigated for the cause of her back pain. Plain X-rays did not reveal any abnormality, but magnetic resonance (MR) scan revealed marked oedema within both sides of the sacrum, suggesting a neoplastic lesion. Bone scintigraphy did show a hyperfixation pattern forming an 'H' in the sacrum which is a characteristic sign of SIF. Computed tomography (CT) confirmed sclerotic changes interpreted as insufficiency fractures through both sacral alae. Increased awareness of these fractures may help to avoid unnecessary investigations and treatment. Bed rest and analgesia followed by rehabilitation provide good relief of symptoms.

Benzidine-DNA adduct levels in human peripheral white blood cells significantly correlate with levels in exfoliated urothelial cells

In a cross-sectional study of 33 workers exposed to benzidine and benzidine dyes and 15 non-exposed controls, we previously reported that exposure status and internal dose of benzidine metabolites were strongly correlated with the levels of specific benzidine-DNA adducts in exfoliated urothelial cells. We also evaluated DNA adduct levels in peripheral white blood cells (WBC) of a subset of 18 exposed workers and 7 controls selected to represent a wide range of adducts in exfoliated urothelial cells. Samples were coded and then DNA was analyzed using 32P-postlabeling, along with n-butanol extraction. One adduct, which co-chromatographed with a synthetic N-(3'-phospho-deoxyguanosin-8-yl)-N'-acetylbenzidine standard, predominated in those samples with adducts present. The median level (range) of this adduct in WBC DNA was 194.4 (3.2-975) RAL x 10(9) in exposed workers and 1.4 (0.1-6.4) in the control subjects (p = 0.0002, Wilcoxon Rank Sum Test). There was a striking correlation between WBC and exfoliated urothelial cell adduct levels (Pearson r = 0.84, p < 0.001) among exposed subjects. In addition, the sum of urinary benzidine, N-acetylbenzidine and N,N'-diacetylbenzidine correlated with the levels of this adduct in both tissues. This is the first study in humans to show a relationship for a specific carcinogen adduct in a surrogate tissue and in urothelial cells, the target for urinary bladder cancer.

Transcranial magnetic stimulation: specific and non-specific facilitation of magnetic motor evoked potentials

Different physiological mechanisms of facilitation of latencies and amplitudes of magnetic motor evoked potentials (MEPs) were evaluated in a cohort of 140 healthy volunteers. The potentials were induced at the vertex and recorded at the abductor pollicis brevis. The aim of the present investigation was to compare physiological mechanisms which presumably facilitate motor pathways at the cortical level with those known to occur during contraction of small hand muscles. When compared with MEPs at rest, the maximum average decrease of latencies (1.5, SD 1.1 ms) as well as the highest increase of peak to peak amplitudes (2.6, SD 2.1 mV) was observed during exertion of a voluntary background force, at the muscle recorded from. Pre-innervation of a neighbouring muscle (abductor digiti minimi) led to a lesser average decrease of latencies by 1.0, SD 1.1 ms and an average increase of amplitudes by only 0.5, SD 1.5 mV. Non-specific manoeuvres, like sticking out the tongue or counting aloud, reduced mean latencies slightly by 0.4 ms, SD 0.8 ms and 0.3 SD 0.85 ms respectively, but increased amplitudes markedly by an average of 1.0, SD 1.6 mV and 0.8, SD 1.4 mV respectively. It is concluded that facilitation of MEPs by non-specific manoeuvres occurs and must be taken into account when evaluating MEPs.