[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.

[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.

Percutaneous endoscopic gastrostomy in head and neck cancer patients: indications, techniques, complications and results

The aim of this study was to review our experience in percutaneous endoscopic gastrostomy (PEG) performed in patients with cancer of the upper aerodigestive tract. Descriptive retrospective study of 142 patients (115 males, 27 females), mean age 62.4 years (25-84 years), with head and neck or esophageal cancer, who underwent PEG tube insertion between January 2006 and December 2008. The studied parameters were indications, success rate, rate and type of complications, and their management. Percutaneous endoscopic gastrostomy was inserted before chemoradiation therapy in 80% and during or after cancer treatment in 20% of the patients. PEG placement was possible in 137 patients (96%). Major complications were observed in 9 (7%) and minor complications in 22 (17%) of the 137 patients. Seven of the 9 patients with a major complication needed revision surgery. The mortality directly related to the procedure was 0.7%. Percutaneous endoscopic gastrostomy tube insertion has a high success rate. In patients with upper aerodigestive tract cancer, PEG should be the first choice for enteral nutrition when sufficient oral intake is not possible. Although apparently easy, the procedure may occasionally lead to severe complications. Therefore, a strict technique and knowledge of clinical signs of possible complications are mandatory.

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.

Extensive (8 to 12 cm2) noncircumferential endoscopic mucosal resection for early esophageal cancer

BACKGROUND

Endoscopic mucosal resection (EMR) is an appealing method for treating intramucosal esophageal cancer but must comply with the following stringent requirements: proper preoperative staging, complete resection of the lesion, obtaining a resected specimen for histologic analysis of safety margins, and squamous reepithelialization without stricture formation.

METHODS

A rigid esophagoscope was created to resect up to 12 cm(2) of esophageal mucosa in a single specimen and at a constant depth through the submucosa. Under visual control, the esophageal mucosa is sucked into a transparent window and resected with a thin diathermy wire loop in 10 seconds. After extensive preclinical studies in a sheep model, this article reports our early experience in humans.

RESULTS

Twenty-one hemi-circumferential EMRs were performed for 11 dysplastic Barrett's esophagi and 10 early squamous cell carcinomas with no perforation, one hemorrhage controlled by embolization of the left gastric artery, and one incomplete resection. Deep safety margins were clear in 19 of 21 resected specimens (2 patients, unfit for operations, had submucosal invasion of squamous cell carcinoma and adenocarcinoma, respectively). Lateral margins were not clear by definition in 7 circumferential Barrett's esophagi, but were clear in 4 incomplete Barrett's esophagi and 10 early squamous cell carcinomas.

CONCLUSIONS

Large EMRs of 12 cm(2) can safely be performed at the submucosal level in the esophagus. Although feasible in one session, circumferential EMR in humans is not yet advisable because of the risk of stricture formation during the healing phase. The rate of complications of this series of 21 EMRs in humans is acceptable.

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.

Human astrovirus gastroenteritis in children, Madagascar, 2004-2005

We report data regarding the molecular epidemiology of human astrovirus (HAstV) infections among children in Madagascar. In a 13-month study, 5 HAstV isolates were detected in fecal samples from 237 children (2.1%) by reverse transcription-PCR. Phylogenetic analysis showed the cocirculation of usual and unusual HAstVs.

Norovirus infection in children with acute gastroenteritis, Madagascar, 2004-2005

Of 237 children with acute gastroenteritis in Antananarivo, Madagascar, during May 2004–May 2005, 14 (≈6%) were infected with norovirus. Seasonality (November–December peak) was detected. Reverse transcription–PCR identified GII as the most common genogroup. GIs belonged to GI.1, GI.3, and GI.4. Noroviruses in Madagascar show extensive genetic diversity.

In vitro activities of 18 antimicrobial agents against Staphylococcus aureus isolates from the Institut Pasteur of Madagascar

BACKGROUND

Staphylococcus aureus, one of the most frequently isolated pathogens in both hospitals and the community, has been particularly efficient at developing resistance to antimicrobial agents. In developed countries, as methicillin-resistant S. aureus (MRSA) has prevailed and, furthermore, as S. aureus with reduced susceptibility to vancomycin has emerged, the therapeutic options for the treatment of S. aureus infections have become limited. In developing countries and especially African countries very little is known concerning the resistance of S. aureus to antibiotics. In Madagascar no data exist concerning this resistance.

OBJECTIVE

To update the current status of antibiotic resistance of S. aureus in Antananarivo, Madagascar.

METHODS

Clinical S. aureus isolates were collected from patients at the Institut Pasteur of Madagascar from January 2001 to December 2005. Susceptibility tests with 18 antibiotics were performed by the disk diffusion method.

RESULTS

Among a total of 574 isolates, 506 were from community-acquired infections and 68 from nosocomial infections. There was no significant difference in the methicillin resistance rate between community-acquired strains (33 of 506; 6.5%) and nosocomial strains (3 of 68, 4.4%). Many MRSA isolates were resistant to multiple classes of antibiotics. Resistance to tetracyclin, trimethoprim-sulfamethoxazole and erythromycin was more common. Among MRSA isolates resistance rates to rifampicin, fusidic acid, gentamicin and ciprofloxacin were lower than that observed with other drugs easily available in Madagascar. No isolates were resistant to glycopeptides.

CONCLUSION

The rate of methicillin-resistant S. aureus is not different between community-acquired and nosocomial infections and is still rather low in Madagascar.

Fungus balls of the paranasal sinuses: a review

In the past 30 years, thanks in part to the advance of both endoscopic technology and imaging possibilities, the classification, diagnosis, and management of rhinosinusitis caused by fungi have been better defined. These are basically divided into invasive and non-invasive forms based on the presence or absence of microscopic evidence of fungal hyphae within the tissues. Among the non-invasive fungal sinus diseases, fungus ball has been increasingly reported and large published series have allowed better characterization of the disease and the treatment strategies. Fungus ball of the paranasal sinuses is defined as the non-invasive accumulation of dense fungal concrements in sinusal cavities, most often the maxillary sinus. To describe this entity, confusing or misleading terms such as mycetoma, aspergilloma or aspergillosis would be best avoided. Clinical presentation is non-specific and the diagnosis is usually suspected on imaging studies. Surgical treatment, usually through an endonasal endoscopic approach, is curative. In this paper, we review the clinical, radiological, and pathological presentation of the fungus ball of the paranasal sinuses as well as the surgical management with emphasis on the transnasal endoscopic approach.

Antimicrobial resistance among uropathogens that cause community-acquired urinary tract infections in Antananarivo, Madagascar

BACKGROUND

Urinary tract pathogens obtained from patients in Madagascar are becoming increasingly resistant to commonly used antibiotics that are readily available at a low price. This poses a real problem for the treatment of community-acquired urinary tract infections (UTIs) in Madagascar.

OBJECTIVES

To obtain data on the pathogens responsible for community-acquired UTIs in Antananarivo and on their susceptibility patterns to the antimicrobial agents that are currently used to treat UTIs.

METHODS

We conducted a retrospective study on bacteria isolated from the urine of patients at the Institut Pasteur of Madagascar between January 2004 and April 2006.

RESULTS

We isolated 903 pathogens from 673 women and 213 men. The most commonly isolated bacteria were Escherichia coli (607 strains), Klebsiella pneumoniae (87 strains), Staphylococcus aureus (35 strains) and Proteus mirabilis (32 strains). Seventy-seven per cent of Gram-negative bacilli were resistant to amoxicillin, 65.7% were resistant to trimethoprim/sulfamethoxazole and more than 15% were resistant to ciprofloxacin. Strains were rarely resistant to more expensive antibiotics (ceftriaxone 5.9%, fosfomycin 4.6%). Most bacteria showed intermediate susceptibility to nitroxolin. Resistance rates of E. coli to ceftriaxone and gentamicin increased significantly between 2005 and 2006, due to the increase in strains harbouring an extended-spectrum beta-lactamase. Gram-positive bacteria, Streptococcaceae and Staphylococcus spp. were rarely resistant, but 9.5% of streptococci were resistant to penicillin A and 8% of staphylococci were resistant to oxacillin.

CONCLUSIONS

The rate of amoxicillin- and trimethoprim/sulfamethoxazole-resistant Enterobacteriaceae implies that another antibiotic should be used for empirical treatment and that there is a need for new generic drugs in developing countries, especially in Madagascar.

Extended endoscopic mucosal resection in the esophagus and hypopharynx: a new rigid device

We present a new device allowing for the diagnosis and treatment of extended superficial lesions of the esophagus and hypopharynx such as early squamous cell carcinoma, intestinal metaplasia with high grade intraepithelial neoplasia or early adenocarcinoma arising in Barrett's esophagus. A new modified rigid esophagoscope (Karl Storz GmbH, Germany) has been designed. A large mucosal area is sucked against a transparent and perforated hemi-cylindrical 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 cm(2). Circumferential resection consists of two opposite individual hemi-circumferential resections. We performed three series of animal trials: hemicircumferential mucosectomies; circumferential resections of variable (2 to 6 cm) length and long-segment mucosectomies with follow-up. Hemi- and circumferential resections could be done in one or two specimens only which allowed precise histological studies. This facilitated easy orientation and analysis of the surgical margins. The deep resection margin was precisely located at the submucosal level, a prerequisite for a safe resection of superficial cancers of the esophagus and hypopharynx.

[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.

Sexually Transmitted Infections in Rural Madagascar at an Early Stage of the HIV Epidemic

BACKGROUND AND OBJECTIVES

Sexually transmitted infections (STIs) in Madagascar have primarily been monitored in selected groups of patients attending STI clinics in major cities as part of the HIV surveillance program in Madagascar.

GOAL OF THE STUDY

The aim of the study was to provide complementary data related to STI prevalence in a general rural population.

STUDY DESIGN

STIs were investigated in 643 subjects aged 15 to 49 years as part of a cross-sectional morbidity study of urogenital schistosomiasis. Infection rates were reassessed 3 weeks and 6 months after systematic STI treatment at baseline.

RESULTS

Neisseria gonorrhoeae (Ng), Chlamydia trachomatis (Ct), Mycoplasma genitalium (Mg), Trichomonas vaginalis (Tv), and/or antibodies to Treponema pallidum (Tp) were diagnosed in 125 (37.5%) of 333 women and in 83 (26.8%) of 310 men. In addition, 49% of the women and 28% of the men were infected with herpes simplex virus-2. Six (0.9%) subjects were found HIV-antibody positive. Between the 3-week and 6-month follow-up surveys Ng, Ct, and/or Mg prevalence increased most prominently in women aged 15 to 24 years.

CONCLUSION

Study findings suggest that rural areas in Madagascar should be as closely monitored and assisted in STI and HIV control as their urban counterparts. Following the current consensus, young adults should constitute a priority target group in the control programs.

[Cervical nodules: diagnosis and management]

Family physicians frequently encounter patients with neck lumps. The causes are numerous but in the adult the origin is most often a lymph node, the majority of which are malignant. Inappropriate management may often lead to a very poor outcome. Relevant investigations must therefore be correctly chosen. The risk for a neck lump to be malignant depends mainly on age, male sex, and alcohol and tobacco consumption and to a lesser extent on a family history for head and neck malignancy. Careful medical history looks for symptoms such as dysphagia, pain, dysphonia, otalgia, or weight loss. On physical examination, the location, size, consistency and mobility of the mass is described. A careful inspection of the scalp, skin of the face and mucosal surface of the upper aerodigestive tract is performed followed by palpation. If no inflammatory or tumoral lesion is identified, the next step is to perform a fine needle aspiration biopsy of the neck mass which will most often lead to a definite diagnosis. When this is not the case, an otolaryngology consultation and excisional biopsy should be obtained.

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.

HIV, STIs, and sexual behaviors among men who have sex with men in Phnom Penh, Cambodia

A probability sample of 206 men who have sex with men from 16 sites in Phnom Penh were surveyed about sexual behaviors and tested for HIV and sexually transmitted infections (STIs). HIV and syphilis prevalence was 14.4% and 5.5%, respectively. Out of the total sample, 81% reported anal sex with any male partners in the past 6 months, and 61.2% reported having had vaginal sex. In the past 6 months, 82.8% of the sample reported having male partners who paid them to have sex. Self-reported sexual orientation did not match well with self-reported sexual behavior. Significant risk factors for HIV infection were anal sex with multiple partners, unprotected vaginal sex with commercial female partners in the past month, and any STI. Complex sexual networks indicate that men who have sex with men act as a bridge between higher and lower HIV prevalence populations. Better prevention efforts structured around behaviors rather than sexual identities are needed.

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.

Photoeradication of Helicobacter pylori using 5-aminolevulinic acid: preliminary human studies

BACKGROUND AND OBJECTIVES

Helicobacter pylori (HP) is an endemic pathogenic bacterium causing gastritis and gastroduodenal ulceration in humans and is linked to the development of gastric malignancies. These first human in vivo studies investigated the photoeradication of HP using laser and white light.

STUDY DESIGN/MATERIALS AND METHODS

In 13 HP-positive volunteers, a zone of gastric antrum was irradiated with laser (410 nm, 50 J/cm(2)) or endoscopic white light (10 J/cm(2)) 45 minutes after oral 5-aminolevulinic acid (5-ALA) 20 mg/kg. HP-eradication was assessed by biopsy urease test and HP-culture from irradiated and control zones 5 minutes, 4 and 48 hours post-irradiation.

RESULTS

A maximum eradication effect was achieved at 4 hours post-irradiation when 85% of biopsies in the monochromatic and 66% in the white light exposed zones, and 58 and 33% in the respective control zones were HP-negative.

CONCLUSIONS

HP numbers were greatly reduced following exposure to 5-ALA and either laser or white light in vivo. Photoeradication appears feasible, but further light dosimetry and the development of convenient application methods is required.

In vivo autofluorescence imaging of early cancers in the human tracheobronchial tree with a spectrally optimized system

The changes in the autofluorescence characteristics of the bronchial tissue is of crucial interest as a cancer diagnostic tool. Evidence exists that this native fluorescence or autofluorescence of bronchial tissues changes when they turn dysplastic and to carcinoma in situ. There is good agreement that the lesions display a decrease of autofluorescence in the green region of the spectrum under illumination with violet-light, and a relative increase in the red region of the spectrum is often reported. Imaging devices rely on this principle to detect early cancerous lesions in the bronchi. Based on a spectroscopic study, an industrial imaging prototype is developed to detect early cancerous lesions in collaboration with the firm Richard Wolf Endoskope GmbH, Germany. A preliminary clinical trial involving 20 patients with this spectrally optimized system shows that the autofluorescence can help to detect most lesions that would otherwise have remained invisible to an experienced endoscopist under white light illumination. A systematic off line analysis of the autofluorescence images pointed out that real-time decisional functions can be defined to reduce the number of false positive results. Using this method, a positive predictive value (PPV) of 75% is reached using autofluorescence only. Moreover, a PPV of 100% is obtained, when combining the white light (WL) mode and the autofluorescence (AF) mode, at the applied conditions. Furthermore, the sensitivity is estimated to be twice higher in the AF mode than in WL mode.

Antigen-specific and persistent tuberculin anergy in a cohort of pulmonary tuberculosis patients from rural Cambodia

Purified protein derivative (PPD) skin testing is used to identify persons infected with Mycobacterium tuberculosis (Mtb) and to assess cell-mediated immune responses to Mtb. However, lack of skin induration to intradermal injection of PPD or PPD anergy is observed in a subset of patients with active tuberculosis (TB). To investigate the sensitivity and persistence of PPD reactivity and its in vitro correlates during active TB disease and after successful chemotherapy, we evaluated the distribution of skin size induration after intradermal injection of PPD among 364 pulmonary TB patients in Cambodia. A subset of 25 pulmonary TB patients who had a positive skin reaction to mumps and/or candida antigens showed persistent anergy to PPD after successful completion of TB therapy. Strikingly, in vitro stimulation of T cells from persistently anergic TB patients with mumps but not PPD resulted in T cell proliferation, and lower levels of IL-2 and IFN-gamma and higher levels of IL-10 were detected in PPD-stimulated cellular cultures from PPD-anergic as compared with PPD-reactive pulmonary TB patients. These results show that anergy to PPD is antigen-specific and persistent in a subset of immunocompetent pulmonary TB patients and is characterized by antigen-specific impaired T cell proliferative responses and a distinct pattern of cytokine production including reduced levels of IL-2.

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.

Etiology of encephalitis syndrome among hospitalized children and adults in Takeo, Cambodia, 1999-2000

Whether or not Japanese encephalitis virus (JEV) is an important causative agent of acute encephalitis in Cambodia remains unclear. This study was carried out to determine the cause of encephalitis syndrome among children and adults admitted to Takeo Provincial Hospital from October 1999 to September 2000. Ninety-nine cases were included in the study: 52 pediatric cases (12 were fatal) and 47 adult cases (10 were fatal). A causative agent such as human herpesvirus (HHV-3 or HHV-4), Cryptococcus neoformans, or Mycobacterium tuberculosis had been identified in 8 of the 11 adults who had human immunodeficiency virus type 1 (HIV-1). An infectious agent was identified in 35 (40%) of 88 HIV-1-seronegative patients (60% of the causes remains unidentified). These comprised 11 bacterial infections, 1 fungal infection, and 23 viral infections. The viral infections were 1 fatal HHV-4 infection, 5 dengue virus infections (2 fatal), 1 coinfection with flavivirus and alphavirus, and 16 presumptive infections JEV (no virus detected), one case of which was fatal. Infection with JEV, the principal cause identified in the 99 encephalitis syndromes, concerned 16 (31%) of 52 children.

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.