Zooplankton dynamics in a changing environment: A 13-year survey in the northwestern Mediterranean Sea

Dynamics of the subsurface (2-3 m) mesozooplankton (i.e., > 200 μm) in the Bay of Calvi (Corsica, France) were explored, combining time series (2004-2016) of 14 zooplankton groups, wind gusts, water temperature, nitrate and chlorophyll-a. Zooplankton data was obtained through image analysis. While contrasted group-specific seasonal patterns were observed, the most productive zooplankton annual event occurred in April (spring peak), concentrating on average 25% of the total annual abundance. A "typical" year was defined based on the annual succession of different community states, highlighting particular years (2007, 2015 and 2012) mainly characterized by weak spring peak. Environmental influences on the interannual variability of zooplankton were explored and while relationship between chlorophyll-a and zooplankton abundance was unclear, the availability of nutrients (December-March), potentially mediated via the wind regime (October-January) seemed to be essential to the occurrence of the spring peak. Additionally, we observed an influence of temperature, with winter thermal thresholds (between 12.1 °C and 13.4 °C) conditioning the spring peak. Also, the occurrence of lower annual abundances after 2010 was synchronous with the sharp increase of seawater warming trend, especially regarding winter temperature (0.30 °C.year^-1). Finally, winter North Atlantic Oscillation (NAO) was found to be correlated to both winter water temperature and spring peak abundance, which suggests large-scale processes to impact regional zooplankton community.

Changes in Activated Thrombin-Activatable Fibrinolysis Inhibitor Levels Following Thrombolytic Therapy in Ischemic Stroke Patients Correlate with Clinical Outcome

BACKGROUND AND PURPOSE

Thrombin-activatable fibrinolysis inhibitor (TAFI) activation following thrombolysis may affect thrombolysis effectiveness in acute ischemic stroke (AIS). To support this hypothesis, we propose to study the relationship between TAFI consumption, activated/inactivated TAFI (TAFIa/ai) and stroke severity and outcome in 2 groups of AIS patients, one treated and one untreated with intravenous recombinant tissue type plasminogen activator (rt-PA).

METHODS

In this prospective, longitudinal, multicenter, observational study, we aimed to study the association between TAFIa/ai and stroke outcome. TAFI levels were sequentially measured in patients treated with intravenous rt-PA thrombolysis (T), and in patients not given any thrombolytic therapy (NT). Baseline reference values were established in healthy subjects matched for age and gender. The National Institutes of Health Stroke Scale (NIHSS) score assessed at baseline and on day 2 was dichotomized into 2 severity groups (0-7 vs. >7). The modified Rankin Scale (mRS) score at day 90 was dichotomized for favorable (0-1) and unfavorable (2-6) outcomes.

RESULTS

A total of 109 patients were included, with 41 receiving rt-PA. At admission, patients had higher TAFIa/ai levels than reference. A significant increase in TAFIa/ai levels was observed at the end of thrombolysis (mean change from baseline of 963%) and lasted up to 4 h (191%). Higher TAFIa/ai levels were associated with a more severe day 2 NIHSS score (p = 0.0098 at T2h post thrombolysis) and an unfavorable mRS score from T48h (p = 0.0417) to day 90 (p = 0.0046). In NT patients, higher TAFIa/ai levels at admission were associated with a more severe stroke, as assessed by day 2 NIHSS score (p = 0.0026) and mRS score (p = 0.0003).

CONCLUSION

These data demonstrate a consistent relationship between TAFI levels and early clinical severity during rt-PA treatment.

Long-term mesocosms study of the effects of ocean acidification on growth and physiology of the sea urchin Echinometra mathaei

Recent research on the impact of ocean acidification (OA) has highlighted that it is important to conduct long-term experiments including ecosystem interactions in order to better predict the possible effects of elevated pCO2. The goal of the present study was to assess the long-term impact of OA on a suite of physiological parameters of the sea urchin Echinometra mathaei in more realistic food conditions. A long-term experiment was conducted in mesocosms provided with an artificial reef in which the urchins principally fed on algae attached to the reef calcareous substrate. Contrasted pH conditions (pH 7.7 vs control) were established gradually over six months and then maintained for seven more months. Acid-base parameters of the coelomic fluid, growth and respiration rate were monitored throughout the experiment. Results indicate that E. mathaei should be able to regulate its extracellular pH at long-term, through bicarbonate compensation. We suggest that, within sea urchins species, the ability to accumulate bicarbonates is related to their phylogeny but also on the quantity and quality of available food. Growth, respiration rate and mechanical properties of the test were not affected. This ability to resist OA levels expected for 2100 at long-term could determine the future of coral reefs, particularly reefs where E. mathaei is the major bioeroder.

[An update on bone anchored hearing aids]

Hearing loss represents a hidden handicapwith various repercussions on development and social life. In the majority of cases, classical hearing aids address most hearing losses. However, the enhancement required for severe deafness frequently involves sound distortions which are very uncomfortable for patients. With the advent of bone anchored hearing aids, conductive hearing losses as well as mixed hearing losses are now better rehabilitated. Recently their indications have been expanded to profound to severe sensorineural hearing loss. The emergence of new materials as well as subcutaneous implants has lead to lessen skin complications and has diminished the aesthetic discomfort of this type of hearing devices.

Buffer capacity of the coelomic fluid in echinoderms

The increase in atmospheric CO2 due to anthropogenic activity results in an acidification of the surface waters of the oceans. The impact of these chemical changes depends on the considered organisms. In particular, it depends on the ability of the organism to control the pH of its inner fluids. Among echinoderms, this ability seems to differ significantly according to species or taxa. In the present paper, we investigated the buffer capacity of the coelomic fluid in different echinoderm taxa as well as factors modifying this capacity. Euechinoidea (sea urchins except Cidaroidea) present a very high buffer capacity of the coelomic fluid (from 0.8 to 1.8mmolkg(-1) SW above that of seawater), while Cidaroidea (other sea urchins), starfish and holothurians have a significantly lower one (from -0.1 to 0.4mmolkg(-1) SW compared to seawater). We hypothesize that this is linked to the more efficient gas exchange structures present in the three last taxa, whereas Euechinoidea evolved specific buffer systems to compensate lower gas exchange abilities. The constituents of the buffer capacity and the factors influencing it were investigated in the sea urchin Paracentrotus lividus and the starfish Asterias rubens. Buffer capacity is primarily due to the bicarbonate buffer system of seawater (representing about 63% for sea urchins and 92% for starfish). It is also partly due to coelomocytes present in the coelomic fluid (around 8% for both) and, in P. lividus only, a compound of an apparent size larger than 3kDa is involved (about 15%). Feeding increased the buffer capacity in P. lividus (to a difference with seawater of about 2.3mmolkg(-1) SW compared to unfed ones who showed a difference of about 0.5mmolkg(-1) SW) but not in A. rubens (difference with seawater of about 0.2 for both conditions). In P. lividus, decreased seawater pH induced an increase of the buffer capacity of individuals maintained at pH7.7 to about twice that of the control individuals and, for those at pH7.4, about three times. This allowed a partial compensation of the coelomic fluid pH for individuals maintained at pH7.7 but not for those at pH7.4.

[Surgical treatment of benign paroxysmal positional vertigo]

Benign paroxysmal positional vertigo (BPPV) is a common disorder that presents to the general practitioner. This condition represents one of the most common causes of peripheral vertigo. The diagnosis is made on clinical grounds. The treatment relies on repositioning maneuvers with relief of symptoms that occur in a few weeks in the majority of the cases. Rarely, patients are incapacitated by persistent or recurrent BPPV despite multiple repositioning maneuvers. In these cases, surgical therapies are available which provide excellent results.

Links between bacterial communities in marine sediments and trace metal geochemistry as measured by in situ DET/DGT approaches

Our current view about the relationship between metals and bacteria in marine sediments might be biased because most studies only use ex situ approaches to quantify metals. The aim of the present research was to compare ex situ and in situ methods of metal measurement (DET and DGT--diffusive equilibration or diffusive gradients in thin-films) and relate the results with two commonly used microbiological variables (bacterial biomass and bacterial diversity as revealed by DGGE). No previous studies have used such in situ approaches in microbial ecology. For biomass and most of the investigated trace metals (Ag, Cd, Sn, Cr, Ni, Cu, Pb, and Al) no significant correlations were found. The exceptions were Fe, Mn, Co, and As which behave like micronutrients. For bacterial diversity, no relevant relationships were found. We conclude that in situ methods are more adapted tools for microbial ecologists but that ex situ approaches are still necessary.

Molecular characterization of rotavirus strains circulating among children with acute gastroenteritis in Madagascar during 2004-2005

A survey was undertaken of the etiology of acute gastroenteritis in children <16 years of age in Antananarivo, Madagascar, from May 2004 through May 2005. With use of electron microscopy of fecal specimens, 104 (36%) of 285 children were found to be infected with rotavirus. Rotavirus strain characterization was undertaken using enzyme-linked immunosorbent assay, electropherotyping, reverse-transcription polymerase chain reaction genotyping, and nucleotide sequencing. The predominant group A rotavirus strain types identified were P[4]G2 (62%) and P[8]G9 (23%). Nucleotide sequence analysis of the VP7 genes of selected Malagasy G2 and G9 strains demonstrated similarity with those of other recently identified African rotavirus strains belonging to the same genotype.

Cryptosporidium species causing acute diarrhoea in children in Antananarivo, Madagascar

A 13-month study of children presenting with acute diarrhoeal disease at hospitals and rehydration clinics in Antananarivo, Madagascar, was undertaken between May 2004 and May 2005. Cryptosporidiosis accounted for diarrhoea in 12 (5.6%) of the 215 children investigated. Cases of cryptosporidiosis were detected only in the rainy season, and the median age of cases was 13.5 months (range=1 day-27 months). As 11 of the cases of cryptosporidiosis were caused by Cryptosporidium hominis and only one by C. parvum, most of the cases were probably the result of anthroponotic transmission. GP60/45/15 gene polymorphisms indicated that the causative pathogens were of subtypes Ia, Id, Ie and IIc.

[Diagnosis of malaria in Antananarivo City: examination of the results obtained at the Institut Pasteur de Madagascar from 2001 to 2004]

Malaria diagnosis is part of the daily activities of the Clinical Biology Center (CBC) of the Institut Pasteur de Madagascar in Antananarivo. Over a period of four years (2001-2004), regardless the methods being used, out of 6537 blood samples examined, 159 (2.43%) tests were positive. All four species of Plasmodium infecting human. were detected with a high prevalence of P. falciparum (87.2%). 49/159 patients were foreigners, but their files did not allow us to distinguish imported from locally acquired malaria cases. Also, among Malagasy patients, there was no possibility to recognize introduced malaria cases (contracted in coastal areas). In Madagascar malaria remains a public health problem. But fever and recent history of fever are often considered and treated as malaria. Our results demonstrated that confirmed malaria rate was very low. Reporting malaria on the basis of clinical signs overestimates malaria cases at the national level. The importance of malaria biological diagnosis is discussed in this article.

Les teignes à madagascar : enquête dans une école d’Antsirabé

BACKGROUND

Tinea capitis is a common infection among schoolchildren in developing countries. This condition is still under-reported in Madagascar. In order to assess the prevalence of Tinea capitis in Madagascar, we conducted a study in a primary school in Antsirabe, a town located in the country's high central territories.

METHODS

Samples were taken from 210 children in the 4 school classes aged between 6 and 14 years. Only children with scaling lesions or with alopecia were sampled. No microsporic gray-patch ringworm was found in any of the children. Samples were obtained from a total of 83 children. Cotton swabs moistened with distilled sterilized water were rubbed on the children's scalps for 15 seconds and the scales thus collected were then seeded on 2 separate tubes of Sabouraud-Dextrose-Agar media containing chloramphenicol, one with and the other without cycloheximide. The tubes were incubated at a temperature of 27 degrees C for 4 weeks. All the micromycetes were identified (dermatophytes, yeasts and molds).

RESULTS

Three species of dermatophytes were isolated: one anthropophilic species, responsible for black-dot ringworm (Trichophyton tonsurans), and 2 geophilic dermatophytes, unusual in human disease (Microsporum boullardii and Trichophyton terrestre). Of the 83 children sampled, 17 had 20 dermatophytes (in 3 children, 2 different species of dermatophytes were associated). We collected 15 Trichophyton tonsurans (2 Trichophyton tonsurans were associated with Microsporum boullardii, and 1 with Trichophyton terrestre), and 2 Microsporum boullardii. The prevalence of carriers of dermatophytes was 8 p. 100 for all children and 20.5% for the sampled children.

DISCUSSION

Children in Madagascar, unlike those in Central Africa, do not develop microsporic gray-patch ringworm caused by Microsporum langeronii. However, they may present tinea capitis with small alopecic lesions, or they may frequently have Trichophyton tonsurans and seem to have healthy scalps. In contrast with Central Africa, where T. soudanense is the main cause of black-dot ringworm, and with North Africa, where T. violaceum is most frequently seen, these 2 species are not found in Antsirabe. Studies carried out in coastal regions with a more tropical climate could perhaps show other dermatophytes responsible for tinea capitis. Anthropophilic tinea capitis caused by Trichophyton tonsurans is endemic in the Antsirabe area. The lesions are inconspicuous with diffuse scaling, like those reported in surveys conducted in the USA. Mycological investigation followed up by topical treatment with a fungicide could diminish the spread of this anthropophilic, and thus contagious, dermatophyte. Trichophyton tonsurans has also reappeared regularly in France over the past few years.

[Endoscopic mucosal resection for the treatment of superficial adenocarcinima developed on the Barrett's mucosa]

We present a new technique of endoscopic mucosal resection for the treatment of extended superficial lesions of the esophagus such as early squamous cell carcinoma, high grade intraepithelial neoplasia or early adenocarcinoma arising in Barrett's esophagus. A modified rigid esophagoscope has been designed. A large mucosal area is sucked against a perforated 180 degrees window. Mucosal resection is performed by an electrical wire loop at a constant depth of 1 +/- 0,1 mm. The resected surface varies from 4 to 12 cm2. Circumferential resection consists of two opposite hemi-circumferential resections. The resection yields one or two specimens only for histological study allowing easy orientation and analysis of the resection margins. The deep resection margin is precisely located at the submucosal level, a prerequisite for a safe resection of T1a cancers.

Evaluation of the attachment strength of individuals of Asterina gibbosa (Asteroidea, Echinodermata) during the perimetamorphic period

A turbulent channel flow apparatus was used to determine the adhesion strength of the three perimetamorphic stages of the asteroid Asterina gibbosa, i.e. the brachiolaria larvae, the metamorphic individuals and the juveniles. The mean critical wall shear stresses (wall shear stress required to dislodge 50% of the attached individuals) necessary to detach larvae attached by the brachiolar arms (1.2 Pa) and juveniles attached by the tube feet (7.1 Pa) were one order of magnitude lower than the stress required to dislodge metamorphic individuals attached by the adhesive disc (41 Pa). This variability in adhesion strength reflects differences in the functioning of the adhesive organs for these different life stages of sea stars. Brachiolar arms and tube feet function as temporary adhesion organs, allowing repetitive cycles of attachment to and detachment from the substratum, whereas the adhesive disc is used only once, at the onset of metamorphosis, and is responsible for the strong attachment of the metamorphic individual, which can be described as permanent adhesion. The results confirm that the turbulent water channel apparatus is a powerful tool to investigate the adhesion mechanisms of minute organisms.

Endoscopic mucosal resection in the esophagus with a new rigid device: an animal study

BACKGROUND AND STUDY AIMS

: There is a growing trend toward the use of minimally invasive endoscopic methods to treat early esophageal cancers. Although there is continuing controversy regarding the management of Barrett's esophagus and the value of surveillance programs continues to be debated, the ultimate goal is to eradicate all of the foci of intestinal metaplasia and hence the risk of developing an adenocarcinoma. A number of ablative techniques have so far been applied, but none has yet been shown to be superior and entirely satisfactory. The present study evaluates the feasibility, efficacy, and safety of a promising new method of endoscopic mucosal resection (EMR) in a sheep model, based on the use of a modified rigid esophagoscope.

MATERIALS AND METHODS

The resectoscope consists of a rigid esophagoscope with a distal transparent window through which the mucosa and part of the submucosa are sucked in and then resected with a wire loop. The sheep model was chosen because of its similarities to human anatomy with regard to the thickness and histological structure of the esophagus. Fifty-five separate hemicircumferential resections and 11 circumferential resections were carried out in 21 and 11 animals, respectively. Mitomycin C, an agent inhibiting fibroblast proliferation, was administered at different time intervals after eight circumferential resections to prevent the development of esophageal strictures.

RESULTS

All of the specimens of hemicircumferential resections were obtained as single distinct pieces and were easily examined histologically. The surface of the specimen correlated with the size of the window and ranged from 6 to 12 cm (2). In circumferential resections, the specimens were obtained in two pieces. An accurate resection depth through the submucosa was achieved in 58 of 65 resected specimens. No complications occurred after hemicircumferential resections. Complications after circumferential resections (stenosis or perforation, or both) were minimized after appropriate timing of mitomycin C administration.

CONCLUSIONS

This EMR method offers a promising approach in comparison with other options currently available. It appears to be superior in terms of the size of the resected specimen, the precision and regularity of the resection depth, and the accuracy of histological diagnosis with safety margins. Hemicircumferential EMRs have been shown to be safe in the sheep model. This new technique warrants further animal studies before being used for circumferential EMR in humans.

Endoscopic fluorescence detection of intraepithelial neoplasia in Barrett's esophagus after oral administration of aminolevulinic acid

BACKGROUND AND STUDY AIMS

Barrett's esophagus is strongly associated with adenocarcinoma. Early malignant transformation of the Barrett's mucosa is often not visible endoscopically and may remain undetected until the invasive adenocarcinoma stage. Endoscopic surveillance is currently carried out on random four-quadrant biopsies at 1-2 cm intervals. Endoscopic fluorescence detection of protoporphyrin IX induced by 5-aminolevulinic acid can identify premalignant lesions. This study evaluates endoscopic fluorescence detection in patients having Barrett's esophagus and compares the results to those of standard endoscopy with random four-quadrant biopsies.

PATIENTS AND METHODS

The study included 30 examinations in 28 patients (22 men, 6 women; age range 37-78 years, mean age 60 years,), with five patients having known intraepithelial neoplasia. A dose of 20 mg/kg of 5-aminolevulinic acid was given orally 5 hours before examination. Random four-quadrant biopsies were performed 4-6 weeks before endoscopic fluorescence detection.

RESULTS

Of the biopsies taken during the endoscopic fluorescence detection procedure, 28 % (23/81) were true positives. More than one-third of the false-positive results were due to inflammation. None of the 97 control biopsies taken on nonfluorescing areas during endoscopic fluorescence detection were dysplastic. Endoscopic fluorescence detection showed low-grade intraepithelial neoplasia in five patients which was not diagnosed with random four-quadrant biopsies, while random four-quadrant biopsies alone showed three low-grade intraepithelial neoplasias that were invisible during endoscopic fluorescence detection. All high-grade intraepithelial neoplasias or adenocarcinomas (2/2) were detected with both methods.

CONCLUSIONS

Fluorescence detection achieved a similar performance when compared with four-quadrant random biopsy, but resulted in fewer biopsies (81 for endoscopic fluorescence detection vs 531 for random four-quadrant biopsies).

One-step immunochromatographic dipstick tests for rapid detection of Vibrio cholerae O1 and O139 in stool samples

We describe the development and evaluation of a rapid diagnostic test for Vibrio cholerae O1 and O139 based on lipopolysaccharide detection using gold particles. The specificity ranged between 84 and 100%. The sensitivity of the dipsticks ranged from 94.2 to 100% when evaluated with stool samples obtained in Madagascar and Bangladesh. The dipstick can provide a simple tool for epidemiological surveys.

Optimization of the diameter of a radial irradiation device for photodynamic therapy in the esophagus

BACKGROUND AND STUDY AIMS

Photodynamic therapy (PDT) is a local therapeutic technique based on the photosensitization of lesions using a dye prior to light-induced tissue destruction. PDT of intraepithelial neoplasia in Barrett's esophagus, or of early squamous-cell carcinoma of the esophagus, requires light application devices that allow homogeneous and well-defined illumination of the tissue surface. Such devices must be large enough to induce complete unfolding of the esophagus in spite of esophageal motility and elasticity. The aim of this study was therefore to determine the optimal diameter of a cylindrical illumination device for PDT in this organ.

PATIENTS AND METHODS

The study included nine patients (aged 49-72 years) who underwent panendoscopy. Flexible transparent hollow tubes with diameters ranging from 13 to 19 mm were successively introduced into the esophagus, and the esophageal wall was viewed from the inside through the tube using a flexible small-diameter endoscope. The number of folds was counted. Observations of the upper, middle, and lower thirds of the esophagus were recorded. The radial location of the folds was also recorded, and defined as follows: anterior wall (up), posterior wall (down), side walls (right, left).

RESULTS

No significant difference in the number of folds between the lower and middle parts of the esophagus was noticed. However, the upper third had significantly fewer folds (about 30 %) than the other two parts. For diameters above 17 mm, this difference was less dramatic. The number of such folds was shown to decrease with the increasing diameter of the device.

CONCLUSIONS

It appears that 18 mm or more is the optimal diameter for a fixed-geometry cylindrical photodynamic therapy irradiating device for the patient category considered in this study. It was also observed that most folds were located on the side walls of the esophagus.

Localization of tetra(m-hydroxyphenyl)chlorin (Foscan) in human healthy tissues and squamous cell carcinomas of the upper aero-digestive tract, the esophagus and the bronchi: a fluorescence microscopy study

To date, little is known about precise time-dependent distribution and histological localization of tetra(m-hydroxyphenyl)chlorin (mTHPC) in human healthy tissues and squamous cell malignancies in the upper aero-digestive tract. A fluorescence microscopy study was performed on 50 healthy tissue biopsies and on 13 tumors (graded from Tis to T1 SCC) from 30 patients. Tissue samples were taken between 4 h and 11 days following injection of 0.15 mg/kg mTHPC. A fairly comparable distribution pattern in various tissues was observed over time in different patients. Vascular localization of mTHPC fluorescence predominates at a short delay, whereas the dye is essentially located in the tumoral and healthy mucosa after longer delays. A much lower uptake and retention of mTHPC fluorescence was noted in striated muscle and cartilage as compared to neoplastic lesions. No significant selectivity was found between healthy and tumoral mucosa. The obtained data are important to confirm drug-light interval that have been selected for effective PDT for early SCC malignancies while minimizing the risks of over- or under-treatment. The low fluorescence level in striated muscle provides the opportunity to develop interstitial PDT as a treatment modality for invasive SCC of unfavorable locations in the oral cavity or pharynx, such as the base of the tongue.

In vivo autofluorescence spectroscopy of human bronchial tissue to optimize the detection and imaging of early cancers

We are developing an imaging system to detect pre-/early cancers in the tracheo-bronchial tree. Autofluorescence might be useful but many features remain suboptimal. We have studied the autofluorescence of human healthy, metaplastic and dysplastic/CIS bronchial tissue, covering excitation wavelengths from 350 to 480 nm. These measurements are performed with a spectrofluorometer whose distal end is designed to simulate the spectroscopic response of an imaging system using routine bronchoscopes. Our data provide information about the excitation and emission spectral ranges to be used in a dual range detection imaging system to maximize the tumor vs healthy and the tumor vs. inflammatory/metaplastic contrast in detecting pre-/early malignant lesions. We find that the excitation wavelengths yielding the highest contrasts are between 400 and 480 nm with a peak at 405 nm. We also find that the shape of the spectra of healthy tissue is similar to that of its inflammatory/metaplastic counterpart. Finally we find that, when the spectra are normalized, the region of divergence between the tumor and the nontumor spectra is consistently between 600 and 800 nm and that the transition wavelength between the two spectral regions is around 590 nm for all the spectra regardless of the excitation wavelength, thus suggesting that there might be one absorber or one fluorophore. The use of backscattered red light enhances the autofluorescence contrast.

Pharmacokinetics and pharmacodynamics of tetra(m-hydroxyphenyl)chlorin in the hamster cheek pouch tumor model: comparison with clinical measurements

The pharmacokinetics (PK) of the photosensitizer tetra(m-hydroxyphenyl)chlorin (mTHPC) was measured by optical fiber-based light-induced fluorescence spectroscopy (LIFS) in the normal and tumoral cheek pouch mucosa of 29 Golden Syrian hamsters with chemically induced squamous cell carcinoma. Similar measurements were carried out on the normal oral cavity mucosa of five patients up to 30 days after injection. The drug doses were between 0.15 and 0.3 mg per kg of body weight (mg/kg), and the mTHPC fluorescence in the tissue was excited at 420 nm. The PK in both human and hamster exhibited similar behavior although the PK in the hamster mucosa was slightly delayed in comparison with that of its human counterpart. The mTHPC fluorescence signal of the hamster mucosa was smaller than that of the human mucosa by a factor of about 3 for the same injected drug dose. A linear correlation was found between the fluorescence signal and the mTHPC dose in the range from 0.075 to 0.5 mg/kg at times between 8 and 96 h after injection. No significant selectivity in mTHPC fluorescence between the tumoral and normal mucosa of the hamsters was found at any of the applied conditions. The sensitivity of the normal and tumoral hamster cheek pouch mucosa to mTHPC photodynamic therapy as a function of the light dose was determined by light irradiation at 650 nm and 150 mW/cm2, 4 days after the injection of a drug dose of 0.15 mg/kg. These results were compared with irradiations of the normal oral and normal and tumoral bronchial mucosa of 37 patients under the same conditions. The reaction to PDT of both types of human mucosae was considerably stronger than that of the hamster cheek pouch mucosa. The sensitivity to PDT became comparable between hamster and human mucosa when the drug dose for the hamster was increased to 0.5 mg/kg. A significant therapeutic selectivity between the normal and neoplastic hamster cheek pouch was observed. Less selectivity was found following irradiations of normal mucosa and early carcinomas in the human bronchi. The pharmacodynamic behavior of mTHPC was determined by test irradiations of the normal mucosa of hamsters and patients between 6 h and 8 days after injection of 0.5 and 0.15 mg/kg in the hamsters and the patients, respectively. The normal hamster cheek pouch showed a maximum response to irradiation 6 h after injection and then decreased continuously to no observable reaction at 8 days after injection. The reaction of the normal human oral mucosa, however, showed an increasing sensitivity to the applied light between 6 h and 4 days after mTHPC injection and then decreased again at 8 days. The hamster model with the chemically induced early squamous cell cancer in the cheek pouch thus showed some similarity to the early squamous cell cancer of the human oral mucosa considering the PK. However, a quantitative difference in fluorescence signal for identical mTHPC doses as well as a significant difference in pharmacodynamic behavior were also observed. The suitability of this animal model for the optimization of PDT parameters in the clinic is therefore limited. Hence great care must be taken in screening new dyes for PDT of early squamous cell cancer of the upper aerodigestive tract based upon observables in the hamster cheek pouch model.

[Impact of diagnosis and treatment of early stage secondary tumors on outcome for the oncologic ORL patient]

OBJECTIVE

To study the incidence, location and stage of second primary tumours in patients with head and neck cancer and analyse the survival and outcome of patients with early-stage second primary tumours.

METHODS

Retrospective chart review of patients treated for head and neck cancer from 1989 to 1993. Survival analyses and statistical comparisons with the Kaplan-Meier method and log-rank test.

RESULTS

99 of the 311 patients had second primary tumours. 45 patients had synchronous second primary tumours and 54 metachronous second primary tumours, diagnosed at an early stage (stage 0 or I) in 78 and 63% of cases respectively. Patients with second primary tumours had a significantly (p = 0.03) lower survival rate than patients with single tumour. However, for patients with early stage second primary tumours survival was not significantly decreased (p = 0.3).

DISCUSSION

This study confirms the high incidence of second primary tumours and their negative impact on the outcome of patients with head and neck cancer. Early diagnosis and treatment of second primary tumours results in a survival rate very similar to that of patients with a single head and neck cancer. This provides indirect evidence that in patients with curable initial head and neck cancer intensive screening for second primary tumours may result in an improved overall outcome.

Pulse oximeter as a cause of skin burn during photodynamic therapy

Photodynamic therapy is increasingly being used for the treatment of various cancers. However, this technique has a major adverse effect, namely skin photosensitization. An unusual case of skin burn associated with pulse oximetry during photodynamic therapy in a patient treated for an early esophageal tumor is described. The patient, who was treated with mTHPC, suffered a second-degree burn on the index finger with subsequent loss of the nail. The only previously reported case of such a complication occurred with Photofrin, whereby no tissue other than skin was damaged.

Abrasive esophageal cytology for the oncological follow-up of patients with head and neck cancer

OBJECTIVES

The occurrence of a second primary cancer in the esophagus in patients with head and neck squamous cell carcinoma is frequent and is associated with a poor prognosis. The aim of this study was to evaluate the yield of abrasive esophageal cytology as a means of screening for metachronous cancer of the upper aerodigestive tract.

STUDY DESIGN

We retrospectively reviewed the results of abrasive esophageal cytology performed twice yearly for the screening of patients with prior head and neck cancer.

METHODS

From 1987 to 1996, 320 patients treated for head and neck cancer underwent 1,673 abrasive cytology examinations of the esophagus during a mean follow-up period of 4 years. Cytological results were classified as negative, suspect, or positive for malignancy.

RESULTS

Twenty-five patients without symptoms had one or more suspect or positive cytologic findings, leading to 29 endoscopic examinations. These revealed 20 premalignant or early malignant lesions of the esophagus (2 dysplasias, 18 squamous cell carcinomas), 2 glandular carcinomas, and 10 clinically unsuspected oral or pharyngeal carcinomas. In seven patients, positive cytological results were associated with clinically visible head and neck cancer. Of the 34 patients with suspect cytological results for malignancy, 10 had no evidence of tumor at endoscopy and 24 had no endoscopic examination because of refusal or because suspected cells were not found in additional examinations. Negative results on cytological examination were found for 254 patients throughout their follow-up, and none of them developed esophageal cancer during a mean follow-up period of 3 years.

CONCLUSIONS

For patients with head and neck cancer, abrasive sponge cytology is useful for detecting esophageal cancer at an early stage. In addition, it may reveal unsuspected second primaries or recurrences in the head and neck region.

Stability of the fluorescence measurement of Foscan in the normal human oral cavity as an indicator of its content in early cancers of the esophagus and the bronchi

Photodynamic therapy (PDT) with Foscan (mTHPC) is used to cure early cancers of the esophagus or the tracheobronchial tree. However, fixed PDT parameters (drug dose, light dose, etc.) do not permit an accurate prediction of the tissue damage. Large interpatient fluctuations in tissue drug level, at the time of light application, suggest that the light dose must be adjusted to the drug dose shortly before the PDT. This drug dose can be measured endoscopically by light-induced fluorescence spectroscopy, but this measurement is inconvenient and somewhat difficult. A better test site, yielding comparable information, is needed. The oral cavity seems ideal. However, it first had to be established to what extent the estimation of the drug dose was dependent upon the location of the measurement and the pressure applied to the probe. These measurements prove to be not only correlated to similar measurements in the esophagus or the bronchi but also more consistent and less sensitive to the location and the applied pressure. The buccal mucosa is therefore recommended as a test site for measuring the Foscan fluorescence signal at the time of PDT in the esophagus or the bronchi. This measurement is accurate enough for use in light-dose adjustment.

Clinical evaluation of the cutaneous phototoxicity of 5,10,15,20-tetra(m-hydroxyphenyl)chlorin

The cutaneous phototoxic reaction induced by intravenous injection of 5,-10,-15,-20-tetra(m-hydroxyphenyl)chlorin (mTHPC) has been clinically evaluated in patients undergoing photodynamic therapy. These tests were performed on the backs of 23 patients with a solar simulator at various times after drug administration ranging from 5 h to 57 days. The mTHPC doses ranged from 0.1 to 0.3 mg/kg, and the illuminations lasted from 30 s up to 8 min. These tests have shown that the duration of the skin photosensitization induced after a typical therapeutic dose of mTHPC (0.15 mg/kg) is less important than with Photofrin (2 mg/kg). The level of mTHPC in the skin was also assessed in vivo and at times corresponding to the irradiations using an optical fiber-based spectrofluorometer. This study indicates that the light-induced fluorescence spectroscopy of mTHPC enables prediction of the degree of photosensitivity of the skin.

Clinical photodynamic therapy for superficial cancer in the oesophagus and the bronchi: 514 nm compared with 630 nm light irradiation after sensitization with Photofrin II

Photodynamic therapy (PDT) for cancer in the oesophagus and bronchi with red (630 nm) light may occasionally lead to wall perforation and fistula. Therefore, we investigated the clinical use of a less penetrating wavelength (514 nm) for the curative treatment of nine superficial carcinomas in the oesophagus and bronchi after photosensitization with Photofrin II. Tumours without infiltration beyond the submucosa in the oesophagus and beyond the lamina propria in the bronchi were considered as superficial cancers. The outcome and complications were compared with those of 13 superficial cancers treated with PDT and 630 nm light. In addition, we evaluated histologically the extent of the long-term tissue damage and scarring following treatment of six oesophageal cancers with either green or red light. At first endoscopic control, 7-10 days after PDT, tissue necrosis simply matched the illuminated area, without evidence of selective tumour damage. Six of nine tumours treated with 514 nm light had a complete response compared with nine of 13 after 630 nm irradiation. No perforation or fistula occurred in either treatment group. However, severe chest pain and fever with or without pleural effusion, consistent with occult perforation, were observed in three patients after 630 nm illumination in the oesophagus. Histologically, fibrous scarring in the three distinct sites treated with green light was limited to the superficial layers of the oesophagus. After red light treatment, transmural fibrosis with marked thinning of the oesophageal wall was evident in two of the three specimens available for inspection. These results indicate that PDT with 514 nm light has the potential to cure superficial cancer in the oesophagus and bronchi with essentially the same probability of success as red light. In the oesophagus, green light prevents deep tissue damage, thus reducing the risk of perforation.

Photodynamic therapy of early squamous cell carcinomas of the esophagus: a review of 31 cases

BACKGROUND AND STUDY AIMS

Patients with cancers of the head and neck have a strong tendency to develop early synchronous and metachronous carcinomas of the esophagus. In many of these patients, whose general condition is poor as a result of alcohol and tobacco abuse, the second primary cancers require minimally invasive treatment. The aims of this study were to evaluate the efficacy of photodynamic therapy for the treatment of early esophageal carcinomas and to compare the results obtained with three different photosensitizers (hematoporphyrin derivative), porfimer sodium (Photofrin II), and meta-(tetrahydroxyphenyl)chlorin (m-THPC).

PATIENTS AND METHODS

Thirty-one early squamous cell carcinomas (Tis or T1a) of the esophagus were treated by photodynamic therapy in 24 patients. Nine tumors were treated with hematoporphyrin derivative, eight with Photofrin II and 14 with m-THPC.

RESULTS

The early cancers were cured in 84% of patients after a mean follow-up period of 2 years. Because the number of cases included in each group was small, the differences in recurrence rates for the different photosensitizers could not be evaluated statistically, but m-THPC was more phototoxic, induced a shorter period of photosensitization of the skin, and had better selectivity than either of the other photosensitizers. There were four major complications: two stenoses and two esophagotracheal fistulas.

CONCLUSIONS

Photodynamic therapy eradicates early squamous cell carcinomas (Tis and T1a) of the esophagus efficiently. Transmural necroses leading to fistulas can be avoided by using a low-penetrating wavelength of laser light (green light at 514.5 m instead of red light at 630 or 652 nm). Stenoses always result from circumferential irradiation of the esophageal wall, and this can be avoided by using a 180 degrees or 240 degrees windowed cylindrical light distributor.

[The current status of broncho-esophagoscopy in otorhinolaryngology]

Most bronchoscopies and esophagoscopies are currently performed with flexible instruments by the respective specialist. Thus the field of bronchoesophagology is in danger of being fragmented; neither the pneumologist nor the gastroenterologist have the complete overview of the upper respiratory and digestive tract. This review shows that number of pathologic conditions in the ENT area and the mediastinum involve the upper respiratory as well as the digestive tract, and thus underscore the need for combined tracheobronchial and esophageal endoscopy. Mastering of rigid and flexible endoscopy is mandatory to be efficient in diagnostic and therapeutic broncho-esophagoscopy. The ENT specialist is in the best position to maintain an overview of this whole field. New developments in broncho-esophagoscopy are presented and discussed in terms of cost effectiveness.

[Rapidly progressive ascites]

A 50-year-old woman rapidly developed ascites with jaundice and worsening of general condition. On admission a nodule of the left breast was noted. Workup showed slight anomalies in liver tests and led to the diagnosis of portal hypertension, without visible lesion (CT scan, ultrasonography) of the liver. The patient suffered severe bleeding caused by esophageal varices necessitating urgent sclerotherapy. Several days later, her condition worsened rapidly due to acute respiratory distress syndrome followed by irreversible shock.

Photodynamic therapy for cancer of the upper aerodigestive tract using tetra(m-hydroxyphenyl)chlorin

A major step in the development of photodynamic therapy (PDT) is the clinical optimization and evaluation of new photosensitizers (PS). Ideally, new compounds should be more effective and/or induce fewer side effects than the first generation PS such as hematoporphyrin derivative and Photofrin. We report the results of our study of PDT applied in the human upper aerodigestive tract, using tetra(m-hydroxyphenyl)chlorin (mTHPC) as the photosensitizing drug. Twenty-seven patients with early (i.e., in situ or microinvasive) squamous cell carcinomas and 4 patients with T1 or T2 cancers were studied. In most cases, illumination of the tumor was performed 4 days after i.v. injection of 0.15 mg/kg of mTHPC using 652 or 514 nm laser light. Of the 36 early tumors evaluated 30 (83%) showed no recurrence after a mean disease-free follow-up of 15.3 months (3-35 months). Of the T1 and T2 cancers, only one achieved a complete response. Major complications, all following red light illuminations, included 1 bronchial stenosis, 1 esophagotracheal fistula, and 2 probable occult perforations of the esophagus. PDT in the esophagus with green light renders such perforations essentially impossible, without, however, reducing the efficacy of the treatment. Skin photosensitization, never observed later than the first week after injection, was seen in 12 patients. In conclusion, photodynamic therapy with mTHPC is a safe and effective technique for the treatment of early carcinomas of the upper aerodigestive tract. Its efficacy is much lower for more advanced cancers.