A broadly resolved molecular phylogeny of New Zealand cheilostome bryozoans as a framework for hypotheses of morphological evolution

Larger molecular phylogenies based on ever more genes are becoming commonplace with the advent of cheaper and more streamlined sequencing and bioinformatics pipelines. However, many groups of inconspicuous but no less evolutionarily or ecologically important marine invertebrates are still neglected in the quest for understanding species- and higher-level phylogenetic relationships. Here, we alleviate this issue by presenting the molecular sequences of 165 cheilostome bryozoan species from New Zealand waters. New Zealand is our geographic region of choice as its cheilostome fauna is taxonomically, functionally and ecologically diverse, and better characterized than many other such faunas in the world. Using this most taxonomically broadly-sampled and statistically-supported cheilostome phylogeny comprising 214 species, when including previously published sequences, and 17 genes (2 nuclear and 15 mitochondrial) we tested several existing systematic hypotheses based solely on morphological observations. We find that lower taxonomic level hypotheses (species and genera) are robust while our inferred trees did not reflect current higher-level systematics (family and above), illustrating a general need for the rethinking of current hypotheses. To illustrate the utility of our new phylogeny, we reconstruct the evolutionary history of frontal shields (i.e., a calcified body-wall layer in ascus-bearing cheilostomes) and ask if its presence has any bearing on the diversification rates of cheilostomes.

Design of Bioprosthetic Aortic Valves using biaxial test data

Bioprosthetic Aortic Valves (BAVs) do not have the serious limitations of mechanical aortic valves in terms of thrombosis. However, the lifetime of BAVs is too short, often requiring repeated surgeries. The lifetime of BAVs might be improved by using computer simulations of the structural behavior of the leaflets. The goal of this study was to develop a numerical model applicable to the optimization of durability of BAVs. The constitutive equations were derived using biaxial tensile tests. Using a Fung model, stress and strain data were computed from biaxial test data. SolidWorks was used to develop the geometry of the leaflets, and ABAQUS finite element software package was used for finite element calculations. Results showed the model is consistent with experimental observations. Reaction forces computed by the model corresponded with experimental measurements when the biaxial test was simulated. As well, the location of maximum stresses corresponded to the locations of frequent tearing of BAV leaflets. Results suggest that BAV design can be optimized with respect to durability.

Caloric stimulation with near infrared radiation does not induce paradoxical nystagmus

Near infrared radiation can be used for warm stimulation in caloric irrigation of the equilibrium organ. Aim of this study was to determine whether near infrared radiation offers effective stimulation of the vestibular organ, whether it is well tolerated by the patients and especially whether it is a viable alternative to warm air stimulation in patients with defects of the tympanic membrane and radical mastoid cavities. Patients with perforations of the tympanic membrane (n = 15) and with radical mastoid cavities (n = 13) were tested both with near infrared radiation and warm dry air. A caloric-induced nystagmus could be seen equally effectively and rapidly in all patients. Contrary to stimulation with warm dry air, no paradoxical nystagmus was observed following caloric irrigation with a warm stimulus (near infrared radiation). Results of a questionnaire showed excellent patient acceptance of near infrared stimulation with no arousal effects or unpleasant feeling. In conclusion, near infrared radiation proved to be an alternative method of caloric irrigation to warm dry air in patients with tympanic membrane defects and radical mastoid cavities. Near infrared radiation is pleasant, quick, contact free, sterile and quiet. With this method an effective caloric warm stimulus is available. If near infrared radiation is used for caloric stimulus no evaporative heat loss occurs.

Bilateral posterior semicircular canal aplasia and atypical paroxysmal positional vertigo: a case report

Isolated congenital malformations of semicircular canals are rare abnormalities. Most inner ear abnormalities occur in syndromes and are associated with hearing loss. Unilateral or bilateral single aplasia of one semicircular canal does not usually result in vertigo, but these become clinically important if there are clinical complaints of vertigo. Computed tomography imaging and high resolution magnetic resonance imaging may reveal inner ear abnormalities. The case is presented here of a 46-year-old male with a 10-year history of recurrent positional vertigo with strong onset when changing position to the left side. Magnetic resonance imaging of the inner ear showed a bilateral posterior semicircular canal aplasia as well as an enlarged vestibule on both sides. Dix-Hallpike positional manoeuvre revealed a positional nystagmus in the left head-hanging position of short duration and latency of a few seconds. When rising, vertigo occurred, but no nystagmus was visible. The fast phase of the nystagmus was mainly vertical down-beating with a slight torsional component to the uppermost ear. Although benign paroxysmal vertigo of the anterior canal was suspected, physical therapy was not effective using a modified liberatory manoeuvre. Brandt-Daroff therapy was effective permanently.

Prevalence of obesity in 6- and 9-year-old children living in Central-North Italy. Analysis of determinants and indicators of risk of overweight

The objective of our article is to survey the prevalence of overweight and obesity among 6- and 9-year-old children in Emilia-Romagna, a region of Central-North Italy, and to study the eating habits and behaviours of these children and their families. During 2003 and 2005, we analysed a stratified sample of the general population of children attending pre-school (2681 children aged 6 years) and primary school (2955 children aged 9 years). Their height and weight were measured by healthcare workers. In the 6-year-old children, information concerning their eating habits was collected by means of a questionnaire completed by their parents. The prevalence of overweight was 16.5% in 6-year-old children and 20.6% in 9-year-old children. The increase of overweight from 6- to 9-year-old children was observed in males (13.5% in 6-year-old/21.3% in 9-year-old boys), but not in females. The prevalence of obesity was 8.9% in children aged 6 years and 9.0% in those aged 9 years, and it was higher in comparison with Italian surveys carried out in 1993 and in 2001: 7.5% in 6-year-old and 7.8% in 9-year-old children in 1993, and 6.6% in 6-year-old and 7.2% in 9-year-old children in 2001. In pre-school children, overweight and obesity were closely influenced by the education level, occupation and nutritional status of the parents.

IGFBP-3 and IGFBP-10 (CYR61) up-regulation during the development of Barrett's oesophagus and associated oesophageal adenocarcinoma: potential biomarkers of disease risk

Dys-regulation of the insulin-like growth factor (IGF) system increases the risk of a number of malignancies. The aim of this study was to investigate the role of members of the IGF binding protein (IGFBP) superfamily in the development of oesophageal adenocarcinoma (EAC) and their possible use as markers of disease risk. Expression of IGFBP-2, IGFBP-3, IGFBP-4, and IGFBP-10/CYR61 was assessed using Real-Time-polymerase chain reaction (PCR) and immunohistochemistry in oesophageal tissues from Barrett's oesophagus (BE) patients with and without associated EAC, and in control subjects. IGFBP-3, IGFBP-4, and IGFBP-10/CYR61 mRNA levels were up-regulated in Barrett's (n=17) and tumour tissue of EAC patients (n=18) compared with normal tissue of control subjects without BE or EAC (n=18) (p<0.001). Over-expression of IGFBP-3 and IGFBP-10/CYR61 proteins was observed in Barrett's, dysplastic and tumour tissue of EAC cases (n=47 for IGFBP-10; n=39 for IGFBP-3) compared with adjacent normal epithelium (p<0.050). Notably, IGFBP-3, IGFBP-4, and IGFBP-10/CYR61 expression in Barrett's tissue of EAC cases (n=17) was significantly (p<0.001) higher than in Barrett's tissue of BE patients with no sign of progression to cancer (n=15). Overall, the results suggest that members of the IGFBP superfamily are up-regulated during oesophageal carcinogenesis and merit further investigation as markers of EAC risk.

Endoskopische Untersuchungen der Eustachi-Röhre

BACKGROUND AND OBJECTIVE

Endoscopy of the eustachian tube allows direct examination of endoluminal alterations in the course of the organ. The aim of this study was to describe anatomic and functional findings in healthy awake subjects.

PATIENTS/METHODS

Ten eustachian tubes in six healthy individuals with no history of tube dysfunction were examined under local anesthesia using different types of rigid and flexible endoscopes.

RESULTS

Nine of ten tubes presented with no pathologic finding. The motility of the tube cartilage could be visualized in all cases and showed a wide variety. Prior anesthesia of the mucosa with the subject in the supine position, if necessary supplemented by a tube catheter, rendered the procedure more comfortable.

CONCLUSION

The eustachian tube shows a wide spectrum of anatomic and functional varieties in normal subjects. The method allows comprehensive evaluation of anatomic and functional stenoses of the eustachian tube. The transnasal-transpharyngeal approach allows only limited evaluation of the middle ear structures.

[Bilateral tumor of the nasal vestibule--a case report]

The authors report a case of a bilateral tumor of the nasal vestibule with a six-year history of progressive impairment of nasal breathing. After microsurgical transnasal excision, the finding was diagnosed as bilateral nasolabial cyst.

[Conservative treatment in mild obstructive sleep apnea: comparison of theophylline and nasal continous positive airway pressure ventilation]

BACKGROUND

Comparison of theophylline and nasal continous positive airway pressure-ventilation (nCPAP) in patients non eligible for surgical treatment with obstructive sleep apnea.

PATIENTS AND MATERIALS

In a prospective non-randomized study 60 patients with mild obstructive sleep apnea were investigated. All individuals were not eligible for surgery under general anaesthesia or refused surgical treatment. The efficacy of a daily single dose oral theophylline (5 - 7 mg/kg body weight, n = 30) and nCPAP ventilation (n = 30) was evaluated by apnea-hypopnea index (AHI) and Epworth Sleepiness Scale (ESS). Statistical data analysis was performed using the Wilcoxon-Test.

RESULTS

In the theophylline group 4/26 patients (15 %) showed a mean AHI reduction of 42 %. The ESS-Score improved from 10.0 to 8.0. Therapy compliance was 86 %. The non-responder (22/26 patients, 85 %) group showed a mean AHI increase of 11 % (from 24.6 to 27.3). This difference was not of statistical significance (p < or = 0.878). In the CPAP group the AHI decreased from 23.3 to 2.9 (p < or = 0,0001). Mean ventilation pressure was 6.4 mbar. The ESS-Score improved from 10 to 8. Compliance was 50 %. Six of thirty patients (20 %) did not use the CPAP device regularly. During the first four weeks another nine of thirty (30.7 %) patients turned back the device. Main reasons were discomfort (61 %), noise (38 %), rhinitis, conjunctivitis and discomfort of the partner (10 %).

CONCLUSIONS

None of the treatments investigated can be considered as a substantial alternative for the majority of patients non eligible for surgery. Theophylline has a high compliance but little therapeutic effect. CPAP-ventilation is more effective but has a compliance problem in the patients investigated. Both modalities may have benefit but have to be individually indicated. A multimodal approach may ease the problem.

Abschätzung der Oxygenierung von Kopf-Hals-Karzinomenmetastasen mittels Farbduplexsonographie. Ein neues nicht-invasives Verfahren

BACKGROUND

Tumor oxygenation is an important aspect of radiosensitivity. The authors describe a new method for a non-invasive assessment of tumor oxygenation in head and neck cancer.

PATIENTS AND METHODS

A group of 20 patients with neck metastases of squamous cell cancer of the head and neck region was surveyed. At first a pO (2)-polarography was performed in the metastatic cervical nodes to investigate the tissue oxygenation. In a second step, the vascularisation of these nodes was visualised by color duplex sonography. In order to evaluate the extent of vascularisation in these nodes, the density of color pixels was quantified by a custom-made software program. The color pixel density and the pO (2) values were correlated and the statistic significance was calculated by Pearson's test.

RESULTS

The mean vascularisation as evaluated by the means of color duplex sonography was 7.78 % [95 % CI 6.04 - 9.51]. The interindividual pO (2) values in the stroma of metastatic lymph nodes ranged between 9.0 and 27.4 mmHg (16.6 [95 % CI 14.06 - 19.13]). The mean values of pO (2)-fractions < 2.5/< 5.0/10 mm Hg were 32.25 %, 44.25 % and 53.29 % respectively. The median value of the pO (2)-fraction was 10.49 % [95 % CI 7.13 - 13.85]. The vascularisation as evaluated by color pixel density showed a statistically significant correlation with the pO (2)-fractions < 5.0 and < 10 mmHg (p < 0.045 and < 0.0001) and with the mean (p < 0.002) and median values of tissue pO (2) values (p < 0.0001) in polarography.

CONCLUSION

The results in a limited number of patients suggest, that the proposed sonographic method allows a reliable non-invasive evaluation of tissue oxygenation in cervical metastases of squamous cell head and neck cancers.

[Relevance of colour-duplex echography for detection and therapy of recurrences in the follow-up of head and neck cancer]

BACKGROUND

Head and neck malignancies have a high rate of recurrences. Since the prognosis is often limited an early detection and therapy onset is essential for survival. This study surveys the relevance of regular colour-duplex echography examinations in the follow-up for detection and therapy of recurrent head and neck carcinomas.

PATIENTS AND METHODS

In a prospective non-randomized study 43 patients were surveyed over a mean observation period of 28 (8-44) months. In addition to clinical and colour-duplex echography (CDS) examinations, computed tomography (CT) and positron-emission-tomography using 18fluorodeoxyglucose (PET) were performed.

RESULTS

A recurrence was detected in 17/43 (39.5 %) patients. The median survival was 42 months. CDS was the most reliable procedure for the diagnosis of regional recurrences with an accuracy of 94.2 %. Sensitivity and specificity of CDS for the diagnosis of all recurrences was found to be 80 % and 78,6 % respectively. CT yielded identical results. In PET sensitivity was 82.4 % and specificity was found to be 88.4 %. In clinical examinations including panendoscopy sensitivity was 64.7 % only. In 7/17 recurrences a therapy was performed with curative intention. In 4 cases an early diagnosis by CDS contributed to a successful therapy.

CONCLUSION

CDS is the imaging procedure of choice for the routine follow-up of head and neck cancer patients. In order to perform a comprehensive assessment of the head and neck region, for re-staging and to exclude second primary tumours additional (pan)endoscopy is necessary. CDS supports due to a high resolution and reliability an early therapy onset and a minimal invasive therapy. Thus, this procedure can significantly contribute to the successful treatment of recurrences in head and neck cancer.

[Epiglottic abscess as a rare reason for airway obstruction in adults]

Acute epiglottitis in adults is a potentially life-threatening disease of increasing incidence. Although pharyngitis is the most common cause of sore throat in the adult, acute epiglottitis must be considered in the differential diagnosis when there is unrelenting throat pain and minimal objective signs of pharyngitis. We report the case of a 45-year old man with acute epiglottitis and occlusion of the upper airways due to an epiglottic abscess. A brief discussion of the diagnosis and treatment of adult epiglottitis is presented. Patients with acute painful dysphagia should be considered to have epiglottitis until the diagnosis is proven. Early diagnosis and aggressive airway management can be life saving.

[Long-term results of suture-free cutanous wound closure in head and neck incisions with octylcyanoacrylate topival skin adhesive]

BACKGROUND

Cyanoacrylate monomers have been developed for use as skin adhesives. So far, little is known about long-term results concerning functional and aesthetic results of wound closure with octylcyanoacrylate in head and neck region.

METHODS

In a prospective, non-randomized study we examined in 59 patients who had undergone surgery in the face and the neck in between 04/99 and 05/00 at the ENT-Department, University of Aachen, Germany. The aesthetic and functional outcome of a cutanous wound closure by use of octylcyanoacrylate was evaluated. Patients were seen preoperatively, postoperatively and in a long-term follow-up (average 7.2 months) for wound control, photographs, and evaluation with a standardized questionnary.

RESULTS

In 40 cases a complete follow-up was possible. There were 33 patients (82.5 %) satisfied with the aesthetic and the functional results of wound closure. In four patients (10 %) early complications developed but did not have an impact on the cosmetic result. Three patients showed alterations as hypertrophic scar or persisting redness of the scar in the long-term follow-up.

CONCLUSION

Octylcyanoacrylate tissue adhesive was found to be an effective method of skin closure in clean head and neck incisions. It is a fast and simple method of wound closure, providing good cosmetic results with a low infection rate.

An assisted automated procedure for vessel geometry reconstruction and hemodynamic simulations from clinical imaging

In this paper a method is described to obtain realistic 3-D geometric models of vascular districts from clinical tomographic 3-D images. The aim is the simulation of individual local hemodynamics by means of computational fluid-dynamics (CFD). As a test case, the method is applied to the carotid bifurcation. Attention is focused on the minimisation of the time demanding costs. The proposed procedure has been automated whenever possible and takes about 2h from the acquisition of the images to the attainment of the simulation results, a time lapse compatible with diagnostic exigency.

Heat shock stimulation of a tilapia heat shock protein 70 promoter is mediated by a distal element

We reported previously that a tilapia (Oreochromis mossambicus) heat shock protein 70 (HSP70) promoter is able to confer heat shock response on a reporter gene after transient expression both in cell culture and in microinjected zebrafish embryos. Here we present the first functional analysis of a fish HSP70 promoter, the tiHSP70 promoter. Using transient expression experiments in carp EPC (epithelioma papulosum cyprini) cells and in microinjected zebrafish embryos, we show that a distal heat shock response element (HSE1) at approx. -800 is predominantly responsible for the heat shock response of the tiHSP70 promoter. This element specifically binds an inducible transcription factor, most probably heat shock factor, and a constitutive factor. The constitutive complex is not observed with the non-functional, proximal HSE3 sequence, suggesting that both factors are required for the heat shock response mediated by HSE1.

Diagnosis and staging of head and neck cancer: a comparison of modern imaging modalities (positron emission tomography, computed tomography, color-coded duplex sonography) with panendoscopic and histopathologic findings

OBJECTIVE

To compare the clinical value of positron emission tomography (PET) using fludeoxyglucose F 18, computed tomography (CT), color-coded duplex sonography (CCDS), and panendoscopy in the detection and staging of head and neck cancer.

DESIGN

Prospective nonrandomized controlled study.

SETTING

Medical school.

PATIENTS

Convenience sample of 50 patients with suspected primary or recurrent head and neck cancer.

INTERVENTION

Biopsy, tumor surgery.

MAIN OUTCOME MEASURES

Information of diagnostic procedures compared with histopathologic features.

RESULTS

Both PET and panendoscopy had a sensitivity of 95% and 100% for detection of primary tumor or recurrent carcinomas, respectively. Specificity for PET and panendoscopy was 92% and 85% in primary tumors and 100% and 80% in recurrent carcinoma, respectively. Sensitivity of CCDS and CT was 74% and 68% in primary tumors and 67% and 63% in recurrent carcinomas, respectively. Specificity was 75% and 69% in primary tumors and 100% and 80% in recurrent neoplasms. When assessing neck nodes, all imaging procedures exhibited identical sensitivity (84%). Specificity was 90%, 96%, and 88% in PET, CT, and CCDS, respectively. In recurrent lymph node metastases, sensitivity was 100%, 67%, and 67% and specificity was 87%, 91%, and 87% for PET, CT, and CCDS, respectively.

CONCLUSIONS

Positron emission tomography was the most reliable imaging procedure in the detection of primary tumor and recurrent carcinomas localized in the head and neck region. Owing to its limited anatomical depiction, it cannot as yet replace other diagnostic procedures in preoperative planning but does contribute valuable complementary diagnostic information. Computed tomograpy may have difficulties in identifying recurrent carcinomas. For routine diagnosis of nodal spread in the neck, CCDS is recommended. Panendoscopy is a valuable diagnostic procedure that can provide key information in cases of superficial mucosal tumor involvement. Arch Otolaryngol Head Neck Surg. 2000;126:1457-1461

[Multiple primary carcinomas in patients with head and neck malignancies]

BACKGROUND

Multiple primary tumors can lead to diagnostic and therapeutical problems. In this study we surveyed frequency, localisation, diagnostic, chronologic and therapeutic aspects of multiple primary carcinomas in patients with head and neck tumors.

PATIENTS AND METHODS

The data of 843 patients from the tumor registry of the ENT-clinic Aachen were retrospectively studied.

RESULTS

Larynx (41.87%) and oropharynx (12.57%) were the main localisation of the first primary neoplasma. In 65 patients (7.71%) multiple primary tumors were observed. 24.6% of these tumors occurred synchronously. Preferential localisation of a second tumor were lung (20%), oral cavity (15.3%) and larynx (13.8%). 28.57% of the metachronous tumors were observed after more than five years. In 46.15% clinical complaints led to the suspicion of a second tumor. Panendoscopy was the most reliable diagnostic procedure. The survival rate and time was significantly reduced in patients with synchronous tumors. 3-year survival rate was 15% compared to 81% in patients with metachronous tumor appearance (p < 0.0001).

CONCLUSION

Patients with head and neck tumors have a high incidence of multiple primary malignomas varying from the region of the first presentation of a malignant tumor. Concepts comprising surgery provide the highest survival rates. Because of the high incidence of metachronous carcinomas after five years found in this study, the authors regard a prolonged follow-up period as necessary.

An in vitro study on compensation of mismatch of screw versus cement-retained implant supported fixed prostheses

In common practice a perfect fit of the prosthetic framework with the implant abutments is almost impossible to achieve. The mismatch, which is principally induced by the technological process adopted to manufacture the fixed prostheses, strains the framework thus generating constraint reactions. These are static forces that load the implant components and the bone at the implant-bone interface and may cause the bone remodelling. Depending on the magnitude of such forces, i.e. depending on the magnitude of the mismatch, the bone remodelling may lead to the loosening of the screws and of the implant-bone interface and hence cause implant failure. The present study shows an in vitro comparison of 3 different connecting abutments (standard, EsthetiCone and CerAdapt, Nobel Biocare AB, Göteborg, Sweden) with relation to the mechanical stresses induced by geometrical mismatches (technology induced errors). Two experimental devices were purposely realized and used to assess the ability of the different abutments to compensate errors. One was designed for translation errors and the other for rotation errors. The experimental apparatus set-up includes 2 freestanding implants supporting a prosthetic structure and the connecting abutments. The implants and the abutments were used as delivered by the manufacturer, while the prostheses were purposely realized and instrumented with strain gauges. The data obtained with the error devices do not give quantitative information on what happens in clinical applications where the implants are connected to living bone, which is a tissue much more deformable than the steel used for the error devices. Results allow direct comparisons of the behaviour of the different investigated abutments with respect to position errors. The CerAdapt system (cement retained ceramic abutments) showed the least strain in presence of translation errors. The standard system (screw retained abutments) showed the least strain in presence of rotation errors.

[Nuclear magnetic resonance tomography imaging and functional diagnosis of the eustachian auditory tube]

PURPOSE

To develop and evaluate a protocol for the anatomic depiction and functional testing of the auditory tube with the use of MR imaging.

METHODS

Eleven volunteers were included into this study. For the morphological assessment, the imaging protocol included axial and coronal T2-weighted turbo-spin echo sequences (TR/TE = 3194/100 ms) and a T1-weighted gradient echo sequence (TR/TE = 42/4.6 ms). For the functional test a dynamic turbo-gradient echo sequence (TFE) with spectral fat suppression (TR/TE = 15/6.2 ms; 4 sec) was obtained using the single slice technique before and during the Valsalva manoeuvre.

RESULTS

With multi-slice sequences, the osseous part of the auditory tube, the tubal cartilage (middle and lateral lamina), the ciliated epithelium, Ostmann's adipose body and the levator and tensor veli palatini muscles were delineated in all cases. During the Valsalva test, opening of the auditory tube was demonstrated in 20 of the 22 investigated sides using the dynamic TFE single slice sequence.

CONCLUSIONS

The introduced MRI protocol allow visualization of the opening of the auditory tube and provides detailed anatomical information of the nasopharynx. Comprehensive morphological and functional evaluation of the auditory tube becomes possible within a single examination'.

Dose range evaluation of a new inactivated hepatitis A vaccine administered as a single dose followed by a booster

A total of 242 healthy adults were immunised with a first dose of an investigational inactivated hepatitis A vaccine. Three concentrations (3, 6 and 12 EU [ELISA units]) of the experimental vaccine were used and compared to a licensed reference vaccine. The aim was to determine the antigenic concentration of the study vaccine inducing the highest seroconversion rate and anti-Hepatitis A virus (HAV) antibody response at 2 weeks after the primary immunisation. A booster dose was given at month 6. At 15 days after the primary immunisation the seroconversion rates in subjects vaccinated with the 6 and 12 EU vaccines were 78 and 94%, respectively. At 30 and 180 days after the primary immunisation the percentages of seropositivity were 100% for both groups. The antibody response to the 12 EU study vaccine was similar to that to the reference vaccine. The percentages of seropositivity at 15 and 180 days after the primary immunisation were 94 vs 93%, and 100 vs 93% in the experimental and reference vaccine respectively. Thus, because it induces early and lasting seroconversion, the 12 EU study vaccine seems to be the most effective as a high potency HAV vaccine.

[Results of pretherapeutic lymph node diagnosis in head and neck tumors. Clinical value of 18-FDG positron emission tomography (PET)]

BACKGROUND

Histological studies demonstrate that there is a high percentage of occult nodal metastasis in head and neck malignomas. Patients with positive lymph nodes have a comparatively worse prognosis. A neck dissection is required in these cases. By demonstrating morphological abnormalities, imaging procedures like ultrasound, computer tomography (CT), and magnetic resonance imaging (MRI) can provide important initial informations about possible malignant alteration of the lymph nodes. Positron emission tomography (PET) allows functional metabolic imaging of a suspected tumor site. The aim of this study was a comparative evaluation of different diagnostic procedures with special emphasis on the value of PET in the pretherapeutic diagnosis of nodal spread in head and neck cancer.

PATIENTS AND METHODS

Forty patients (28 male and 12 female) with a suspected malignoma in the head and neck region underwent clinical examination including palpation of the neck sides, ultrasound, CT, and PET to detect a nodal spread of the malignancy. Fifty neck dissections were performed in 28 patients. Lymph node biopsies were performed in the remaining patients. The results of the diagnostic procedures were compared to the histology and the clinical course of the patients. The mean follow-up period was 12.5 months.

RESULTS

A nodal metastasis was verified in 35% of all cases. Sensitivity of all imaging procedures including PET was 82%. Palpation had a sensitivity of only 61%. Specificity was 85% for ultrasound, 94% for CT and palpation, and 87% for PET. PET produced false negative results in 13.4% of all cases. Inflammation was detected in these cases. The positive predictive value was marginally better for PET than for ultrasound (77% vs. 75%). It proved to be lower than the values for palpation (86%) and CT (88%). Negative predictive value was 90-91% for all imaging procedures.

CONCLUSION

In the primary diagnosis of nodal alterations in the head and neck region, a PET scan has the same diagnostic value as ultrasound or CT. By imaging the metabolism of a suspected nodal metastasis, PET can help to improve the assessment of regions with uncertain anatomic features. To avoid false positive results, acute and chronic inflammatory alterations have to be ruled out before the PET imaging.

Diagnostic evaluation of malignant head and neck cancer by F-18-FDG PET compared to CT/MRI

AIM

Evaluation of F-18-FDG PET in comparison to CT/MRI as diagnostic tool in primary and recurrent head and neck cancer.

METHODS

78 F-18-FDG PET studies were performed in 71 patients with known or suspected primary (n = 48) or recurrent (n = 30) head and neck cancer and compared to CT (n = 75) or MRI investigations (n = 3) concerning detection of the primary or recurrent tumor and detection of regional lymph node metastases in the ipsilateral and contralateral neck sides. Glucose uptake (SUV) of PET findings was correlated to tumor location, grading and dignity of the lesion.

RESULTS

Sensitivity and specificity for PET in detection of primary tumors were 87%* and 67%, respectively (CT/MRI 67%* and 44%) (*p < 0.05), in detection of local recurrence 86% and 75%, respectively (CT/MRI 57% and 92%), in detection of necks affected by lymph node metastases 80% and 92%, respectively (CT/MRI 80% and 84%). Laryngeal, buccal (cheek) and salivary gland tumors had significant lower glucose uptake (SUV) when compared to tumors of the hypopharynx (p < 0.05). G1-tumors (mean SUV 4.26) had significant (p < 0.05) lower glucose uptake when compared to G2- and G3-tumors (mean SUV 7.73 and 8.19, respectively). Mean SUV of malignant PET findings (7.88) was significant (p < 0.05) higher than mean SUV of benign PET findings (5.70). However, a SUV threshold to improve diagnostic accuracy could not be defined.

CONCLUSIONS

F-18-FDG PET is significantly more accurate than CT/MRI for detection of head and neck cancer. Both methods are valuable for detection of cervical lymph node metastases. Glucose uptake shows correlation to histological grading. A quantitative SUV analysis does not improve diagnostic accuracy.

Diagnostic evaluation of malignant head and neck cancer by F-18-FDG PET compared to CT/MRI

AIM

Evaluation of F-18-FDG PET in comparison to CT/MRI as diagnostic tool in primary and recurrent head and neck cancer.

METHODS

78 F-18-FDG PET studies were performed in 71 patients with known or suspected primary (n = 48) or recurrent (n = 30) head and neck cancer and compared to CT (n = 75) or MRI investigations (n = 3) concerning detection of the primary or recurrent tumor and detection of regional lymph node metastases in the ipsilateral and contralateral neck sides. Glucose uptake (SUV) of PET findings was correlated to tumor location, grading and dignity of the lesion.

RESULTS

Sensitivity and specificity for PET in detection of primary tumors were 87%* and 67%, respectively (CT/MRI 67%* and 44%) (*p < 0.05), in detection of local recurrence 86% and 75%, respectively (CT/MRI 57% and 92%), in detection of necks affected by lymph node metastases 80% and 92%, respectively (CT/MRI 80% and 84%). Laryngeal, buccal (cheek) and salivary gland tumors had significant lower glucose uptake (SUV) when compared to tumors of the hypopharynx (p < 0.05). G1-tumors (mean SUV 4.26) had significant (p < 0.05) lower glucose uptake when compared to G2- and G3-tumors (mean SUV 7.73 and 8.19, respectively). Mean SUV of malignant PET findings (7.88) was significant (p < 0.05) higher than mean SUV of benign PET findings (5.70). However, a SUV threshold to improve diagnostic accuracy could not be defined.

CONCLUSIONS

F-18-FDG PET is significantly more accurate than CT/MRI for detection of head and neck cancer. Both methods are valuable for detection of cervical lymph node metastases. Glucose uptake shows correlation to histological grading. A quantitative SUV analysis does not improve diagnostic accuracy.

[Drug therapy of sleep apnea syndromes: results of short-term treatment with theophylline]

BACKGROUND

In the treatment of obstructive sleep apnoea syndrome (OSA) nasal ventilation therapy (nCPAP) and various surgical strategies like uvulopalatopharyn-goplasty proved effective. However, not all patients can be successfully treated with these therapies. In our study we investigated the effects of oral theophylline taken at night in patients with OSA.

PATIENTS AND METHODS

50 patients with polysomnographically verified OSA were enrolled in two groups in this study. In the therapy group we administered 300-500 mg of oral theophylline at night for 4-22 weeks. In all patients nCPAP therapy was indicated in the beginning of the trial.

RESULTS

We found a positive effect of theophylline treatment in patients with a comparatively low apnoea-hypopnoea index, low overweight and inconspicuous status of the upper airways. In 5 cases the initially indicated nCPAP treatment could be cancelled. In the therapy group the number of apnoea and hypopnoea was reduced by 17.08%. The mean apnoa duration and the time of sleep with an oxygen saturation below 90% was reduced by 8.41% and 19.58%, respectively. In the control group we found an increase in apnoeas and hypopnoeas by 10.48%. Apnoea duration and desaturation time increased by 4.71% and 11.04%, respectively. Comparison of the effects between the two groups using the Wilcoxon 2-sample test proved to be statistically significant. Besides these positive effects we found 27.2% non-responders.

CONCLUSION

Theophylline has a short-term relevant beneficial effect only on patients with mild OSA. Because of the limited beneficial effects, permanent theophylline treatment has to be monitored regularly via control polysomnography. Under certain conditions noctural oral administration of theophylline may supplement conventional therapy strategies.

[Effect of adenoid hyperplasia on nasal airflow]

BACKGROUND

Adenoid hyperplasia is one of the most common reasons for nasal obstruction in childhood. The consequences of a nasopharyngeal obstruction on the airflow in the nasal cavity and the epipharynx were investigated.

MATERIALS AND METHODS

In a model of a nose we conducted experiments with adenoids of different size, documenting their influence on inspiratory and expiratory nasal flow. Rhinoresistometry was performed to obtain further information concerning resistance and turbulence.

RESULTS

The flow experiments showed no alterations of the inspiratory nasal flow regardless of adenoid size. Instead the adenoid had a significant influence on the direction of the expiratory nasal flow in the cavity. Depending on the extension of the hyperplasia, parts of the nasal cavity were excluded from the flow. Rhinoresistometry showed that relation between nasopharyngeal obstruction and nasal resistance was nonlinear.

CONCLUSION

Adenoid hyperplasia affects only expiratory nasal flow. In our model a critical mass seemed to be reached in case of more than 60% nasopharyngeal obstruction. A narrowing of the epipharynx up to 50% of its volume has no significant effects on nasal resistance.

Biomechanics of abdominal aortic aneurysm in the presence of endoluminal thrombus: experimental characterisation and structural static computational analysis

OBJECTIVES

To evaluate the role played by biomechanical and geometrical parameters of endoluminal thrombus and of aortic wall on abdominal aortic aneurysm (AAA) behaviour.

MATERIALS AND METHODS

Tensile tests on 21 AAA thrombus specimens from six patients undergoing AAA repair and numerical evaluation of aneurysmal aortic wall stress and strain distribution. Parameters of the analysis were lumen eccentricity, thrombus Young's Modulus and the aortic wall constitutive equation.

RESULTS

There was a linear stress/strain for all the thrombus specimens. The numerical analyses show the mechanical behaviour of AAA as a function of lumen eccentricity and biomechanical parameters.

CONCLUSIONS

Well organised thrombus reduces the effect of the pressure load on the aneurysmal aortic wall.

Wear of polyethylene cups in total hip arthroplasty: a parametric mathematical model

This paper presents a parametric mathematical model of the head-cup wear coupling in total hip arthroplasty (THA). The model evaluates the dependence of acetabular volumetric wear upon the characteristic parameters of patient and hip prosthesis. Archard's law is assumed to calculate the wear coupling behaviour. The wear factor is taken from pin-on-disc wear tests as a function of materials and finishing of the articular joint. The forces acting on the hip joint are taken from experimental data found in the literature whilst the load distribution is calculated under the hypotheses of perfectly rigid ideal wear coupling. The sliding distance is obtained by combining the three elementary displacements -- due to rotations around the three axes -- at the generic bearing surface location. The simulations show that the polymeric wear volume per step cycle decreases ranging from fast walking speeds to low running speeds, it increases linearly with patient body weight and with femoral head diameter, it decreases slightly for positive variations of the socket inclination angle and it increases exponentially with femoral head roughness. The volumetric wear rate per year calculated for a standard reference patient is 5.8 mm3. The relevant iso-wear maps show a marginal pattern with the maximum located near the cup superior borderline. At the instant of peak load, the iso-stress maps show a paracentral pattern with the maximum superior to the cup polar point, and the iso-sliding distance maps show a marginal pattern with two maxima located near the cup's superior and inferior borderlines.

Optimisation of a stentless valve prosthesis based on an analytic parametric model of the aortic valve

An analytical mathematical model of a stentless aortic valve has been implemented. The valve is characterised by a trileaflet geometry, cylindrical leaflets; the aortic root is schematised by a conical surface which includes the leaflet attachments. The model is defined through six geometric parameters: the base radius, the valve height, the commissure radius, the leaflet radial, circumferential and attachment line lengths. Five performance indexes have been used to optimise the valve geometry, namely: the systolic area, the leaflet circumferential stress in diastole, the leaflet bending strain in systole and two bending angles related to the rotation of the leaflets from the diastolic to the systolic configuration. The sensitivity analysis is carried out which can identify the influence of each geometric parameter on the performance indexes adopted for the optimum valve design. The analysis of the results provides the geometric configuration which optimises the overall function of the valve throughout the cardiac cycle.

Optimisation of a Stentless Valve Prosthesis Based on an Analytic Parametric Model of the Aortic Valve

An analytical mathematical model of a stentless aortic valve has been implemented. The valve is characterised by a trileaflet geometry, cilindrical leaflets; the aortic root is schematised by a conical surface which includes the leaflet attachments.

The model Is defined through six geometric parameters: the base radius, the valve height, the commissure radius, the leaflet radial, circumferential and attachment line lengths. Five performance indexes have been used to optimise the valve geometry, namely: the systolic area, the leaflet circumferential stress in diastole, the leaflet bending strain in systole and two bending angles related to the rotation of the leaflets from the diastolic to the systolic configuration.

The sensitivity analysis is carried out which can identify the influence of each geometric parameter on the performance indexes adopted for the optimum valve design.

The analysis of the results provides the geometric configuration which optimises the overall function of the valve throughout the cardiac cycle.

Assessment of the influence of the compliant aortic root on aortic valve mechanics by means of a geometrical model

In recent years several researchers have suggested that the changes in the geometry and angular dimensions of the aortic root which occur during the cardiac cycle are functional to the optimisation of aortic valve function, both in terms of diminishing leaflet stresses and of fluid-dynamic behaviour. The paper presents an analytical parametric model of the aortic valve which includes the aortic root movement. The indexes used to evaluate the valve behaviour are the circumferential membrane stress and the stress at the free edge of the leaflet, the index of bending strain, the bending of the leaflet at the line attachment in the radial and circumferential directions and the shape of the conduit formed by the leaflets during systole. In order to evaluate the role of geometric changes in valve performance, two control cases were considered, with different reference geometric configuration, where the movement of the aortic root was ignored. The results obtained appear consistent with physiological data, especially with regard to the late diastolic phase and the early ejection phase, and put in evidence the role of the aortic root movement in the improvement of valve behaviour.

Echistatin induces decrease of pp125FAK phosphorylation, disassembly of actin cytoskeleton and focal adhesions, and detachment of fibronectin-adherent melanoma cells

B16-BL6 mouse melanoma cells cultured on fibronectin-coated dishes were detached by treatment with echistatin, an RGD-containing disintegrin. Echistatin was active at micromolar concentrations and was not cytotoxic. Its effect was dose-dependent and reversible. Sequential morphological changes leading to rounding up of the cells were detected by phase-contrast microscopy and by immunofluorescence analysis. A dramatic reduction in the number and size of focal adhesions and loss of cytoplasmic actin filaments were observed well before cell detachment occurred. Echistatin treatment down-regulated the phosphorylation of pp125FAK in fibronectin-adherent cells in a dose- and time-dependent fashion. The reduction of pp125FAK phosphorylation preceded cell detachment and occurred even in the presence of orthovanadate, an inhibitor of protein tyrosine phosphatases. These results suggest that echistatin detaches cells from the fibronectin substratum by inducing a decrease of pp125FAK phosphorylation and that echistatin acts by inhibiting protein tyrosine kinase activity rather than activating protein tyrosine phosphatases.

Amino acid sequence and molecular modelling of glycoprotein IIb-IIIa and fibronectin receptor iso-antagonists from Trimeresurus elegans venom

Low-molecular-mass Arg-Gly-Asp (RGD)-containing polypeptides were isolated from the venom of Trimeresurus elegans by a simple two-step procedure consisting of membrane filtration and reverse-phase HPLC. A combination of electrospray MS, fast-atom bombardment MS and Edman degradation allowed us to ascertain the presence in the venom of different isoforms and to determine their primary structures. The amino acid sequences resembled the structure of elegantin, the only disintegrin previously reported from the T. elegans venom [Williams, Rucinski, Holt and Niewiarowski (1990) Biochim. Biophys, Acta 1039, 81-89]. MS analyses indicated the occurrence of differential proteolytic processing at both the N-terminus and the C-termins of the polypeptide chains. The amino acid sequence alignment of the elegantin isoforms with known components of the disintegrin family demonstrated the complete conservation of the 12 cysteine residues involved in disulphide bridges. Molecular modelling of elegantins predicted an overall folding of these molecules quite similar to that reported for the kistrin solution structure. The newly identified polypeptide isoforms strongly inhibited ADP-induced aggregation in both human and canine platelet-rich plasma but showed a different species-dependent specificity. These molecules were also able to inhibit B16-BL6 murine melanoma cell adhesion to immobilized fibronectin. The comparison of the structures and biological activities of elegantin isoforms and kistrin allowed us to highlight some structural features that, in addition to the RGD locus might be involved in the interaction of these snake-venom polypeptides with the integrin receptors on the platelet and cell surface.

A new pulsatile blood pump for adult cardiopulmonary bypass: design criteria and preliminary fluid dynamic evaluation

A new pulsatile pumping device for adult cardiopulmonary bypass has been designed. Its main characteristic consists in having a fully disposable pumping head, since polymeric materials have been adopted for the housing as well as for the built-in inlet and outlet valves. Furthermore, the valves show an innovative design, as they are ring-shaped and accomplish their task by virtue of their elastic deformability. The design phase of the pumping head and the first fluid dynamic evaluations have been performed by numerical methods. Particularly, a three-dimensional CAD model of the pumping head (in the current configuration) is presented in this paper. On the basis of this model, computational fluid dynamic analysis of the hydraulic behaviour has been performed for some components. The obtained results show complex velocity patterns in the pumping chamber during the filling phase as well as limited pressure gradients across the inlet valve.

Echistatin inhibits the adhesion of murine melanoma cells to extracellular matrix components

Echistatin, an RGD containing peptide isolated from Echis carinatus snake venom, inhibited the in vitro attachment of B16-BL6 mouse melanoma cells to fibronectin, vitronectin and laminin. Its inhibitory activity on cell adhesion was non-cytotoxic, dose-dependent and fully reversible. Kinetic analysis showed a competitive type of inhibition for all the three substrates examined here. Chemical reduction and alkylation of echistatin almost abolished its effect on cell adhesion to extracellular matrix components. Native echistatin was also able to inhibit B16-BL6 cell attachment to IgG antihuman fibronectin receptor-coated wells, thus suggesting that the molecule binds to adhesive receptors on melanoma cell surface. Our results indicate that echistatin is an useful disintegrin for research on cell adhesion.

Glutathione depletion induced in rat liver fractions by seven pesticides

Glutathione (GSH) plays a central role in the chemical detoxication. Xenobiotics which induce GSH depletion, either via GSH conjugation or via oxidation of GSH to glutathione disulfide (GSSG), alter the mechanism of natural cellular defence against toxicants. The aim of this study was to evaluate the ability of seven widely used pesticides (Alachlor, Atrazine, Benomyl, Captan, Linuron, Methyl Parathion and Propanil) and/or of their metabolites to deplete GSH in rat liver fractions. In our experimental conditions, Atrazine, Linuron and Propanil failed to interact with rat liver GSH. Conversely, Alachlor, Benomyl and Methyl Parthion were able to deplete GSH in rat liver, probably by forming GSH conjugates. The fungicide Captan rapidly reduced the rat liver concentration of GSH by converting it to the oxidized form GSSG. But a longer incubation of Captan with rat hepatic enzymes produced the formation of metabolites which depleted GSH via conjugation. Our results suggest that exposure to the pesticides Alachlor, Benomyl, Captan and Methyl Parathion may induce an alteration of natural mechanisms of defence against toxicants in mammals, including humans.

Regulation of the function of eukaryotic DNA topoisomerase I: topological conditions for inactivity

The effects of supercoiling on the cleavage reaction by eukaryotic DNA topoisomerases I (wheat germ, chicken erythrocyte, and calf thymus) have been analyzed on DNA fragments (0.96 and 2.3 kilobases) encompassing an immunoglobulin kappa light-chain promoter. In one topological condition of the substrate, the absolutely relaxed state, cleavage was found to be impeded. This finding defines the topology-dependent step of the eukaryotic DNA topoisomerase I reaction and shows that for the cleavage reaction topology is more critical than sequence effects. These findings suggest a simple model for the regulation of the DNA topoisomerase I reaction based on topological factors, which may explain the regulatory function of the enzyme in in vivo eukaryotic transcription.

Eukaryotic DNA topoisomerase I reaction is topology dependent

The effects of supercoiling on the topoisomerization reaction by eukaryotic DNA topoisomerases I have been analyzed. The systems used were: DNA topoisomerase I from wheat germ, chicken erythrocyte and calf thymus on a 2.3 kb DNA fragment which encompasses the immunoglobulin kappa-light chain (L kappa) promoter of the mouse plasmacytoma MPC11; S. cerevisiae DNA topoisomerase I on a 2.2 kb DNA fragment from the same organism which encompasses the regulatory and the coding region of the ADH II gene; wheat germ DNA topoisomerase I on the plasmid pUC18. It was found in every system that lack of torsional stress prevents topoisomerization of the substrate. A simple regulatory model of DNA topoisomerase I function, based on topological considerations, is presented.

[Lesion of the ramus profundus of the radial nerve (supinator syndrome). Dissociated radial paralysis of the proximal under arm type]

Anatomy and clinical patterns of dissociated distal paralysis of the radial nerve ("supinator syndrome" or paralysis of posterior interosseous nerve) due to trauma, tumors, rheumatic diseases and with spontaneous onset are discussed in the light of the literature and 6 personally observed cases, 5 of them with traumatic lesions. Surgical exploration and intraneural neurolysis resulted in total or partial remission in 5 instances. In our experience surgical exploration should be performed at the earliest moment after spontaneous recovery is no longer to be expected.