Computer vision model for the detection of canine pododermatitis and neoplasia of the paw

BACKGROUND

Artificial intelligence (AI) has been used successfully in human dermatology. AI utilises convolutional neural networks (CNN) to accomplish tasks such as image classification, object detection and segmentation, facilitating early diagnosis. Computer vision (CV), a field of AI, has shown great results in detecting signs of human skin diseases. Canine paw skin diseases are a common problem in general veterinary practice, and computer vision tools could facilitate the detection and monitoring of disease processes. Currently, no such tool is available in veterinary dermatology.

ANIMALS

Digital images of paws from healthy dogs and paws with pododermatitis or neoplasia were used.

OBJECTIVES

We tested the novel object detection model Pawgnosis, a Tiny YOLOv4 image analysis model deployed on a microcomputer with a camera for the rapid detection of canine pododermatitis and neoplasia.

MATERIALS AND METHODS

The prediction performance metrics used to evaluate the models included mean average precision (mAP), precision, recall, average precision (AP) for accuracy and frames per second (FPS) for speed.

RESULTS

A large dataset labelled by a single individual (Dataset A) used to train a Tiny YOLOv4 model provided the best results with a mean mAP of 0.95, precision of 0.86, recall of 0.93 and 20 FPS.

CONCLUSIONS AND CLINICAL RELEVANCE

This novel object detection model has the potential for application in the field of veterinary dermatology.

Novel Management of Masticatory Myositis in Three Dogs with a Selective Janus Kinase (JAK-1) Inhibitor

Masticatory myositis (MM) is an inflammatory myopathy reported in dogs and is characterized by inflammation of the masticatory muscles (temporalis, masseter, and pterygoid muscles). Immunosuppressive therapy is the current recommended treatment for MM and may involve glucocorticoids, cyclosporine, azathioprine, mycophenolate mofetil, leflunomide, or a combination of these treatments that are slowly tapered to the lowest effective dose. However, side effects from multimodal medical therapy and complications associated with MM relapses have been reported. The purpose of this case series was to report oclacitinib as a treatment alternative to traditional medical management of MM. The intent of this alternative is to manage side effects from glucocorticoid use. Oclacitinib (1mg/kg per os q12h) was used solely for treatment of MM in three dogs. The dogs were followed up to >6 months after oclacitinib administration. An increase in oral range of motion, as determined by gape angle, was noted in all three dogs. However, a corresponding drop in antibody titers (2M fiber) did not occur. All dogs showed improvement in overall clinical management of MM, side effects from glucocorticoids, and clinical signs related to chronic prednisone use. Larger controlled trials with consistent measurements (interincisal distance, gape angle) and 2M fiber antibody titers are indicated to further assess validation of oclacitinib treatment of MM. The clinical outcome of all dogs was considered successful.

Independent COL5A1 Variants in Cats with Ehlers-Danlos Syndrome

We investigated four cats with similar clinical skin-related signs strongly suggestive of Ehlers-Danlos syndrome (EDS). Cases no. 1 and 4 were unrelated and the remaining two cases, no. 2 and 3, were reportedly siblings. Histopathological changes were characterized by severely altered dermal collagen fibers. Transmission electron microscopy in one case demonstrated abnormalities in the collagen fibril organization and structure. The genomes of the two unrelated affected cats and one of the affected siblings were sequenced and individually compared to 54 feline control genomes. We searched for private protein changing variants in known human EDS candidate genes and identified three independent heterozygous COL5A1 variants. COL5A1 is a well-characterized candidate gene for classical EDS. It encodes the proα1 chain of type V collagen, which is needed for correct collagen fibril formation and the integrity of the skin. The identified variants in COL5A1 are c.112_118+15del or r.spl?, c.3514A>T or p.(Lys1172*), and c.3066del or p.(Gly1023Valfs*50) for cases no. 1, 2&3, and 4, respectively. They presumably all lead to nonsense-mediated mRNA decay, which results in haploinsufficiency of COL5A1 and causes the alterations of the connective tissue. The whole genome sequencing approach used in this study enables a refinement of the diagnosis for the affected cats as classical EDS. It further illustrates the potential of such experiments as a precision medicine approach in animals with inherited diseases.

In vitro evaluation of potential interference of lokivetmab with protein electrophoresis and immunofixation

OBJECTIVE

In humans, misdiagnoses of monoclonal gammopathy after use of therapeutic monoclonal antibodies has been documented. This triggers concerns for similar misdiagnoses in animals treated with monoclonal antibodies. The aim of this study was to evaluate if lokivetmab interferes with serum protein electrophoresis and immunofixation electrophoresis in dogs.

MATERIAL AND METHODS

Residual sera from 25 client-owned, healthy blood donor dogs from 2 veterinary hospitals in Germany were used. The residual sera were analysed with serum protein electrophoresis and immunofixation electrophoresis before and after being spiked with lokivetmab at a concentration of 10 µg/ml (corresponding to the mean peak serum concentration after a subcutaneous injection of 2 mg/kg lokivetmab).

RESULTS

No monoclonal gammopathy was observed on serum protein electrophoresis and all proteins had a normal distribution pattern without any pathologic bands on immunofixation electrophoresis. The absolute γ-globulin values of spiked samples, however, were significantly higher than in the native sera although they remained within the reference interval. No other globulin fractions were significantly different.

CONCLUSION AND CLINICAL RELEVANCE

This study suggests that lokivetmab at a dose of 2 mg/kg is not detected as a monoclonal peak on serum protein electrophoresis or immunofixation electrophoresis, and thus is unlikely to lead to a misdiagnosis of other diseases that are characterised by monoclonal gammopathies.

Mycobacterium setense isolated from a cat with atypical mycobacterial panniculitis

Atypical mycobacterial panniculitis was diagnosed in a cat. Mycobacterium setense was identified as causative agent by 16 S rRNA gene sequence analysis. This a gram-positive rod-shaped acid-fast bacterium belonging to Mycobacterium fortuitum group was never reported before in diseased animals. Resistance to doxycycline and clarithromycin was detected. During treatment with pradofloxacin, additional resistance to fluoroquinolones developed which was due to a mutation in the gyrase gene gyrA (S90W exchange). Despite of antimicrobial treatment for 33 months the patient did not fully recover. Species identification and susceptibility testing for choosing adequate antimicrobial treatment is recommended in cases of feline mycobacterial panniculitis.

Description and comparison of the skin and ear canal microbiota of non-allergic and allergic German shepherd dogs using next generation sequencing

Atopic dermatitis is one of the most common skin diseases in dogs. Pathogenesis is complex and incompletely understood. Skin colonizing bacteria likely play an important role in the severity of this disease. Studying the canine skin microbiota using traditional microbiological methods has many limitations which can be overcome by molecular procedures. The aim of this study was to describe the bacterial microbiota of the skin and ear canals of healthy non-allergic and allergic German shepherd dogs (GSDs) without acute flare or concurrent skin infection and to compare both. Bacterial 16S rRNA gene amplicon sequence data revealed no differences of bacterial community patterns between the different body sites (axilla, front dorsal interdigital skin, groin, and ear canals) in non-allergic dogs. The microbiota at the different body sites of non-allergic GSDs showed no significant differences. Only for the samples obtained from the axilla the bacterial microbiota of allergic dogs was characterized by a lower species richness compared to that of non-allergic dogs and the bacterial community composition of the skin and ear canals of allergic dogs showed body site specific differences compared to non-allergic dogs. Actinobacteria was the most abundant phylum identified from the non-allergic dogs and Proteobacteria from allergic dogs. Macrococcus spp. were more abundant on non-allergic skin while Sphingomonas spp. were more abundant on the allergic skin. Forward step redundancy analysis of metadata indicated that the household the dogs came from had the strongest impact on the composition of the skin microbiome followed by sex, host health status and body site.

Aktuelle Kenntnisse zu Therapie und Prävention der kaninen Leishmaniose

Die kanine Leishmaniose ist eine Infektionskrankheit, die zunehmend an Bedeutung gewinnt, da auch in Deutschland der Hauptvektor der Leishmaniose vorkommt und Einzelfälle autochthoner Infektionen beschrieben sind. Der Artikel fasst aktuelle Informationen über Therapie und Prävention der Leishmaniose zusammen. Kürzlich wurden bei Hunden, die unter Allopurinoltherapie ein Rezidiv der Erkrankung erlitten, Allopurinol-resistente Leishmania-infantum-Stämme gefunden. Daher werden alternative Langzeittherapien erforderlich. Auch die Ergebnisse aus Langzeitstudien zur Effizienz von Miltefosin im Vergleich zu Megluminantimonat können die Wahl des leishmaniziden Therapeutikums beeinflussen. Eine Vielzahl verschiedener Repellenzien steht zur Übertragungsprophylaxe zur Verfügung. In Europa sind zwei Impfstoffe für Hunde zugelassen, um das Risiko einer aktiven Infektion und den Schweregrad der klinischen Erkrankung zu reduzieren.

Neurotoxicity of vincristine on the medial olivocochlear bundle

OBJECTIVE

Vincristine is a well known neurotoxic chemotherapeutic agent. Dose dependent and cumulative peripheral neuropathy is the main dose limiting side effect of chemotherapy with vincristine. The mechanisms responsible for the neurotoxic effects of vincristine have not yet been fully understood. This prospective study was directed at determining whether vincristine treatment interferes with the function of the medial olivocochlear bundle.

DESIGN

Fifteen children suffering from leukemia were subjected to tympanogram, stapedial muscle reflex, pure tone audiometry and transient evoked otoacoustic emissions (TEOAEs) in the absence and presence of contralateral white noise on day 1 and on day 22 of treatment with vincristine. The function of the medial olivocochlear bundle was assessed by the phenomenon of suppression of otoacoustic emissions by contralateral application of white noise.

RESULTS

The study revealed a statistically significant decrease of contralateral suppression amplitudes in all cases after three sessions of chemotherapy with vincristine. On the contrary no alterations were observed in pure tone audiometry thresholds. A non-significant decrease of the mean TEOAEs' amplitudes was also noted. When analyzed by frequency, however, this decrease reached the level of statistical significance at two frequencies.

CONCLUSION

Vincristine treatment seems to exert a neurotoxic effect on the efferent olivocochlear system, which takes place early in the course of chemotherapy. This is a new aspect to be added to the possible mechanisms underlying the toxicity of vincristine in the auditory periphery. Whether changes in efferent function might contribute to understanding the mechanisms of neurotoxicity caused by vincristine, or find any clinical application as a predictor or early detector of neurological side effects of vincristine still remains to be seen.

The effect of treatment with vincristine on transient evoked and distortion product otoacoustic emissions

OBJECTIVE

Vincristine chemotherapy is mainly associated with neurotoxic effects. The ototoxicity of vincristine has been related to high dosage, while low and moderate doses do not seem to induce significant hearing impairment when measured by pure tone or speech audiometry. Otoacoustic emissions have been reported to be more sensitive in early detection of ototoxicity than conventional pure tone audiometry. The present study was directed at determining whether vincristine treatment interferes with outer hair cell function in the absence of measurable changes in pure tone audiometry.

METHODS

We studied prospectively a cohort of ten children suffering from leukemia. All children were subjected to tympanogram, stapedial muscle reflex, pure tone audiometry, transient evoked (TEOAEs) and distortion product (DPOAEs) otoacoustic emissions on day 1 and on day 22 of treatment with vincristine. TEOAEs were analyzed in terms of emission level and reproducibility as a function of frequency. DPOAEs were obtained as DP-grams and were analyzed in terms of amplitude.

RESULTS

The analyzed parameters of TEOAEs and DPOAEs revealed a declining tendency, although changes did not reach statistical significance. Pure tone audiometry and stapedial reflex thresholds were not altered.

CONCLUSION

For the population of this study, vincristine did not seem to cause significant alterations of otoacoustic emissions' recordings and consequently significant outer hair cell damage.

Transient otoacoustic emissions in the detection of olivocochlear bundle maturation

OBJECTIVE

The medial olivocochlear bundle, forms a neural pathway connecting the superior olivary complex to the outer hair cells of mainly the contralateral cochlea. Although the biological significance of the bundle remains ambiguous, it is clear that activation of medial olivocochlear fibers alters cochlear output and this can be experimentally evident through a series of changes on otoacoustic emissions, called otoacoustic emission suppression. The aim of this study is to observe the maturation of the medial olivocochlear bundle by measuring the suppression effects on transient otoacoustic emissions.

METHODS

The study population consisted of 27 premature babies (53 ears) from the P&A Kyriakou Neonatal Intensive Care Unit (conceptional age: 31-36 weeks) and 43 fullterm babies (61 ears) (conceptional age: 37-42 weeks) from the same unit. The ILO-92 system is used to deliver both the linear clicks to the ear examined (producing the emissions) and the white noise to the contralateral ear. The mode used is based on the alternating on and off presence of the white noise in the contralateral ear.

RESULTS

12/53 (22%) ears of preterm babies presented suppression > or =1 dB. 32/61 (52.4%) ears of fullterm babies presented suppression > or =1 dB. The mean suppression for the ears of premature infants was 0.52 dB, (+/-0.1 S.E.M.). The mean suppression for the ears of fullterm infants was 0.90 dB, (+/-0.09 S.E.M.). At the second half of the time window, suppression of fullterms rises above 1 dB (a pattern similar to that of adults), whereas it remains below 1 dB for preterms.

CONCLUSIONS

Suppression of otoacoustic emissions helps us to study the function of the medial olivocochlear bundle in different populations. It appears in premature babies but becomes stronger as the postconceptional age advances.

IgE sensitization, respiratory allergy symptoms, and heritability independently increase the risk of otitis media with effusion

BACKGROUND AND AIMS

Epidemiological evidence examining the role of atopy and/or allergy in the pathogenesis of otitis media with effusion (OME) is inconclusive. The aim of this study was to assess any increased risk for OME attributable to allergy-related factors, in a well-characterized population using a case-control design and multivariate analysis.

SUBJECTS AND METHODS

Eighty-eight 1-7-year-old children with OME, diagnosed by clinical and tympanometric evaluation and 80 matched controls were enrolled. A standardized questionnaire was completed, in order to assess factors related to OME and allergy-related symptoms and diagnoses using strict clinical definitions. Specific IgE was measured by skin-prick tests and/or CAP-FEIA.

RESULTS

The patient and control groups were well matched. Factors conferring increased risk for OME in the univariate analysis included IgE sensitization, dyspnea, wheezing, asthma, paroxysmal sneezing, rhinitis, eczema, 'any allergic disease,' family history of otitis media, and family history of allergy. After multivariate analysis IgE sensitization, wheezing, nasal obstruction, family history of otitis, and child-care attendance remained as independent risk factors for development of OME.

CONCLUSION

IgE sensitization and respiratory allergy symptoms are independent risk factors for the development of OME, suggesting that both immunological and mechanical pathways may contribute to the development of the disease. Otitis heritability provides additional risk, as well as frequent exposure to viral upper respiratory tract infections in children attending daycare. Treatment and/or prevention of OME using anti-allergic medications should be further examined.

Etiological diagnosis of bilateral, sensorineural hearing impairment in a pediatric Greek population

Early diagnosis, evaluation and treatment of childhood deafness are essential for a child's normal growth. Etiological diagnosis of hearing loss makes prevention, family scheduling and more effective therapy feasible goals. Etiological assessment of sensorineural deafness still remains difficult although recently with the progress of genetics it has become more efficient. In this retrospective study, the etiology of bilateral, sensorineural hearing loss with indication for hearing aids has been studied in 153 hearing impaired children. Etiological diagnosis was based on family and patient record, physical, audiological and laboratory examinations. Among the 94 children who completed the diagnostic protocol etiological groups revealed the following distribution: non-hereditary acquired hearing impairment was present in 36 children (38%) and hereditary was present in 44 (47%) children. The etiology remained unknown in 14 (15%) children. Non-syndromic autosomal dominant type accounted for 13 (29% of hereditary hearing loss) children, non-syndromic autosomal recessive type for 21 (48%) children and syndromic deafness for 10 (23%) children. Modern diagnostic methods, such as genetic testing, help diminish the number of cases with hearing impairment of unknown etiology, for the benefit of children who receive early and appropriate medical, audiologic, genetic and educational counseling based on the etiology of their hearing loss.

The change in the acoustic admittance phase angle: a study in children suffering from acute otitis media

Middle ear mechanics, in normal and in pathological conditions, is the subject of this research, with acoustic impedance measurements as the cornerstone. Previous studies have established the importance of admittance-phase tympanograms, mainly in frequencies higher than the conventional 226 Hz. The purpose of the present study was to record how acute otitis media (AOM) affects the middle ear system and function by evaluating the recordings of the change in phase angle parameter (deltatheta) provided by an automated tympanometer using the sweep-frequency technique. Multifrequency and conventional tympanograms were obtained from 70 children suffering from AOM on consecutive visits. Values of deltatheta from these subjects were compared to normative data previously acquired in our Department. It appears that changes in the mechanical status of the middle ear after AOM are reflected in abnormal deltatheta values, despite the normal findings of conventional tympanometry. A positive history of AOM did not seem to influence the behaviour of the middle ear. In most cases, abnormal deltatheta values coexisted with abnormal values of resonance frequency (RF), i.e. the frequency at which mass and stiffness of the middle ear are in balance, and total susceptance (deltaB) reaches 0mmhos and the converse. The deltatheta seems to be an important indicator of middle ear mechanical status that can record changes occurring in the system after AOM and undetected by low probe-tone tympanometry.

Hearing evaluation with distortion-product otoacoustic emissions in young patients undergoing haemodialysis

Sensorineural hearing loss is frequently reported in young patients with chronic renal failure having haemodialysis. The effect of a single session of haemodialysis on hearing acuity was assessed prospectively in nine children with end-stage renal disease using pure-tone audiometry (PTA) and distortion-product otoacoustic emissions (DPOAEs). Results were compared with those obtained from nine audiologically normal healthy children also tested with PTA and DPOAEs twice during a 4-h interval. Sensorineural hearing loss of unknown aetiology was found in 55.5% of renal patients, mainly in the higher frequencies. Patients on HD had mean PTA thresholds significantly poorer than those of the control group in the frequency range 1000-12 000Hz (P < 0.05). Their mean DPOAE amplitudes were significantly lower in all frequencies > 1184 Hz (P < 0.05). Furthermore, patients' ears with normal PTA thresholds between 250 and 4000 Hz also had decreased DPOAE amplitudes. No significant changes in PTA thresholds or DPOAE amplitudes were encountered in renal patients before and after a HD session (P > 0.05). Changes in PTA thresholds or DPOAE amplitudes were not significantly different than those in the control group (P > 0.05). In conclusion, sensorineural hearing loss of unknown origin, especially in high frequencies, is frequent in young renal patients under HD and single HD sessions do not seem to alter the hearing acuity of these patients. DPOAEs seem to be more sensitive to incipient cochlear damage than behaviour thresholds in monitoring renal patients.

Evoked otoacoustic emissions--an approach for monitoring cisplatin induced ototoxicity in children

OBJECTIVES

Cisplatin chemotherapy is associated with an increased risk of ototoxic changes. The incidence of hearing loss after the 1st cisplatin-infusion session is only scarcely mentioned in the international literature. With increasing survival rates, prevention and/or early detection of ototoxicity are important for providing management options. The predictive value of pure-tone audiometry in early detection of ototoxicity has been questioned, particularly in the higher frequencies. Otoacoustic emissions appear to be more sensitive to cochlear insult than the conventional pure-tone audiometry. The aims of our study was (a) to define the extent of hearing damage in children after the 1st cisplatin-infusion session (50 mg/m(2)); and (b) to compare the efficacy of otoacoustic emissions (transient evoked otoacoustic emissions, distortion-product otoacoustic emissions) with that of pure-tone audiometry as methods of audiological monitoring.

METHODS

Baseline audiometric (0.25-8 kHz) and otoacoustic emission testing (transient evoked otoacoustic emissions, distortion-product otoacoustic emissions) was conducted in 19 children, 12 of whom met the criteria for inclusion in the final study. Comparisons were performed between baseline measurements and those recorded after the 1st cisplatin course. Transient evoked otoacoustic emissions were analyzed in terms of emission level and reproducibility as a function of frequency (0.8-4 kHz). Distortion-product otoacoustic emissions were obtained as DP-grams and I/Q functions at 4,6 and 8 kHz. The DP-gram amplitude, the dynamic range and the detection thresholds from the I/Q functions were determined for each child.

RESULTS

Threshold changes from baseline were founded to be statistically significant from 4-8 kHz in 50% of the children (P<0.01). Transient evoked otoacoustic emissions revealed a significant decrease in the emission level and in the reproducibility at the highest frequency tested (4 kHz, P<0.01), reflecting the results seen in pure-tone audiometry. Distortion-product otoacoustic emissions demonstrated a significant threshold shift, a reduced dynamic range and a decreased amplitude in the frequencies >3 kHz (P<0.05). Furthermore, DP-gram amplitude also reduced significantly at 3 kHz (P<0.05) without any similar change in pure-tone audiometry.

CONCLUSIONS

A significant high-frequency hearing loss is identified in children even after one low-dose cisplatin-infusion session. As ototoxicity screening tools DP-grams were extremely sensitive and superior to pure-tone audiometry and/or transient evoked otoacoustic emissions. Their use is recommended for regular monitoring of cochlear function, aiming in prevention of permanent damage. Some suggestions for reducing the potential for cisplatin ototoxicity (chemoprotective agents, gene therapy, inhibition of apoptosis) are also discussed.

Hearing loss in speech-language delayed children

An infant begins to communicate with his/her environment from the first months of life. However, true words do not appear until the age of 12-15 months, following a rather predictable sequence. Delay or failure of normal language development is not a rare situation in childhood and may be due to a variety of reasons. Among these, hearing undoubtedly plays a leading part in the language acquisition process. The purpose of this study was to assess the percentage of hearing-impaired children in a group of phenotypically healthy children presenting with speech-language delay. Between March 1993 and March 1999, 726 speech-language delayed children were examined in our department. In 72 of them, various diseases or syndromes had already been diagnosed and so they were excluded from the study. The remaining 654 apparently healthy children entered the study and underwent a thorough audiological assessment for determination of their hearing thresholds. Eighty-seven children (13.3%) showed various degrees of hearing loss. Most of them (55 children, 8.4%) suffered from sensorineural hearing impairment, while in 32 children (4.9%) a conductive hearing loss was discovered. The increased prevalence of hearing impairment found in our population mandates a thorough hearing evaluation for every case of speech-language delay, even for those children who show no evidence of other handicaps. This will help in the early diagnosis of hearing loss, allowing proper management to be instituted as early as possible.

Pneumococcal acute otitis media in children

OBJECTIVES

To evaluate the clinical and laboratory findings of Streptococcus pneumoniae acute otitis media in children during a 1 year period.

METHODS

From October 1995 to September 1996, 113 children aged 2 months to 14 years (median 18 months), with S. pneumoniae acute otitis media were studied. Susceptibility testing was performed by the Kirby-Bauer method and the E-test, and serotyping by the Quellung reaction.

RESULTS

E-test assays detected five isolates (4.4%) to be highly resistant to penicillin and 13 (11.5%) that had intermediate resistance. All isolates were found to be susceptible to vancomycin, rifampicin and cefotaxime. In total, 25 isolates (22.1%) were resistant to one or more drugs. Fifty per cent of the penicillin-resistant or intermediately resistant S. pneumoniae isolates were resistant to multiple drugs, whereas only 2.1% of the penicillin-susceptible isolates were resistant to multiple drugs. The predominating serogroups of the isolates with reduced susceptibility to penicillin were the 19 (61.1%), 9 (16.7%), 23 (11.1%), 6 (5.5%) and 14 (5.5%) whereas those of the susceptible isolates were the 19 (26.3%), 14 (13.7%), 3 (11.6%), 6 (11.6%), 9 (8.4%), 1 (5.3%) and 12 (5.3%).

CONCLUSIONS

Streptococcus pneumoniae isolates from children with acute otitis media were penicillin-insensitive in 15.9%. The multiresistant S. pneumoniae isolates belonged to serogroups: 19 (45.4%), 9 (27.3%), 6 (18.2%) and 23 (9.1%).

Multiple-frequency tympanometry in children with acute otitis media

Multiple-frequency tympanometry (MFT) is a sweep-frequency method of acoustic immittance measurement, recently introduced in clinical practice. It provides values for the resonant frequency of the middle ear system. The purpose of this study was to use MFT to collect information about the mechanoacoustical changes occurring to the middle ear system after acute otitis media and to compare it with the results of conventional, low probe-tone tympanometry. Children with acute otitis media were followed up with both methods for 1 month after an episode of acute infection. Also, children with normal hearing were studied to establish normative data. Resonant frequency of the middle ear was found to be lower than normal even 1 month past the initial episode, for all types of 226-Hz tympanograms. MFT seemed to record changes in the middle ear after acute otitis media that 226-Hz tympanometry was unable to detect, implying persistence of pathology. More extended research will illuminate the clinical value of this method in the follow-up of acute otitis media.

Otoacoustic emissions--an approach for monitoring aminoglycoside induced ototoxicity in children

OBJECTIVES

The early detection of hearing impairment caused by ototoxic drugs, such as aminoglycosides, has been the aim of research world-wide. Histopathological studies have shown that the outer hair cells are the most susceptible cochlear components to injury from ototoxic drugs like aminoglycosides. Otoacoustic emissions reflect the functional status of the outer hair cells and constitute the only non-invasive means of objective cochlear investigation. The aim of this study was to evaluate the potential of otoacoustic emissions in early identification of aminoglycoside-induced cochlear dysfunction. In addition, a comparison with pure-tone audiometry or auditory brainstem responses was performed in order to determine if this test might provide a more reliable method of monitoring early ototoxic insults to the cochlea.

METHODS

Twenty four children receiving gentamicin (4 mg/kg once daily) for 6-29 days were included in the study. Eleven children received gentamicin for up to 7 days (group A), while 13 underwent longer-term therapy lasting 8-29 days (group B). Hearing was serially monitored using transient evoked otoacoustic emissions and pure-tone audiometry (0.25-12 kHz) or auditory brainstem responses for younger or uncooperative children. Transient evoked otoacoustic emissions data were analysed in terms of emission amplitude and response reproducibility as a function of frequency.

RESULTS

All patients yielded a normal baseline audiometric assessment upon hospital admission. For group A patients no significant changes in hearing levels were observed either by pure-tone audiometry (P = 0.2), auditory brainstem responses (P = 0.3) or transient evoked otoacoustic emissions (mean response: P = 0.06, reproducibility by frequency: P > 0.05). For group B patients no significant changes in hearing levels measured by pure-tone audiometry (P = 0.1) or auditory brainstem responses (P = 0.4) were observed. Transient evoked otoacoustic emissions however revealed a statistically significant decrease in the mean response level (P = 0.017) and in the reproducibility over the whole frequency spectrum (1 kHz: P = 0.0057, 2 kHz: P = 0.0247, 3 kHz: P = 0.0134, 4 kHz: P = 0.0049, 5 kHz: P = 0.0019).

CONCLUSIONS

The findings suggest that transient evoked otoacoustic emissions are an extremely sensitive measure of the early effects of aminoglycoside-induced injury to the peripheral auditory system. Therefore, their use is recommended for regular monitoring of cochlear function, in the presence of potentially toxic factors, aiming at prevention of permanent damage.

Prognostic value of multiple-frequency tympanometry in acute otitis media

Multiple-frequency tympanometry (MFT) and conventional 226-Hz tympanometry were performed in 86 ears of children affected by acute otitis media (AOM) after therapy. In a 3-month follow-up period, the recurrence rate of AOM and persistence of middle-ear effusion in these children were evaluated in comparison with the early results of the two methods, as well as the relation of MFT findings to the possibility of development of AOM sequelae. It seems that abnormal resonant frequency values and recordings by MFT right after an episode of AOM indicate persistence of changes in the mass and stiffness balance of the middle ear, not demonstrated by conventional tympanometry, that could be responsible for a higher probability of AOM sequelae.

A phase II study with vinorelbine, gemcitabine and cisplatin in the treatment of patients with stage IIIb-IV non-small cell lung cancer (NSCLC)

In our phase II study an acceptable and effective agent like cisplatin was used in combination with vinorelbine and gemcitabine in patients with non-small cell lung cancer (NSCLC). These two new cytostatic drugs have demonstrated, when used as a single-agent treatment, effective response rates (vinorelbine) and minimum toxicity (gemcitabine). The following schedule was used: (i) vinorelbine 25 mg/m2 on days 1 and 8; (ii) gemcitabine 1000 mg/m2 on days 1 and 8; and (iii) cisplatin 75 mg/m2 on day 8. The schedule was repeated every 21 days, with a maximum of six cycles per patient. A total of 31 patients with a mean Karnofsky performance status of 90% were evaluated and 29 of them were finally eligible. Of the patients, five (16.1%) were at stage IIIb and the remainder (83.9%) were at stage IV. The overall response rate was 65% (20 patients); six patients (19.4%) had complete response (CR) and 14 (45.2%) had partial response (PR). Two patients (6.5%) had stable disease and seven (22.6%) had progressive disease. The most notable toxicity was hematologic. Leukoneutropenia was mainly revealed after the third or fourth cycle and granulocyte-colony stimulating factor (G-CSF) was administered in 24 patients (77.4%). Mild anemia was found in almost all patients after the third or fourth cycle (Hb 10-11 g/dl) and eight patients (25.8%) required erythropoietin (EPO). Thrombocytopenia was more often observed compared with other known chemotherapeutic regimens; six patients (19.4%) had grade I thrombocytopenia and therapy was delayed in another four patients (12.9%) due to this complication. Non-hematologic toxicity was mild and well tolerated and consisted of alopecia (54.8%), nausea and vomiting (12.9%), constipation (12.9%), peripheral neuropathy (9.6%), diarrhea (6.5%), stomatitis (3.2%) and local phlebitis (3.2%). The examined combination provides us with one of the best overall responses rates reported, however at the cost of remarkable hematologic toxicity. Therefore, it would be better applied in patients with good performance status. The high response rates give us hope of using this combination as a neoadjuvant regimen.

Multiple-frequency tympanometry in children with otitis media with effusion

Multifrequency tympanograms were recorded from 76 ears of 43 children affected by otitis media with effusion (OME) and 90 ears of normal-hearing children to obtain data for resonance frequency (RF) and changes in phase angle. There was found to be a statistically significant decrease (p < 0.01) in both RF values and change in phase angle in ears with OME compared to normative data. This decrease may be interpreted by considering OME as a mass pathology. Multiple-frequency tympanometry seems to be a useful method for determining the effect of various middle-ear pathologies on the mechano-acoustical status of the middle-ear system.

57Co-bleomycin imaging study of tumors of the head and neck

57Co-Bleomycin (57Co-BLM) was used to visualize malignancies of the head and neck because it does not present the disadvantages of many other radiopharmaceuticals. In a series of 21 patients with 9 control subjects and 12 cases of tumors. 57Co-BLM showed a high and rapid uptake in primary site and metastases of malignant tumors of various histologic types, but not in benign tumors such as angiofibromas. Compared to 67Ga-citrate. 57Co-BLM has many advantages for tumor imaging in the areas of nose, pharynx and larynx: No background activity due to the concentration of 57Co-BLM in normal structures of the head and neck has ever been observed, as opposed to what happens with 67Ga-citrate. Furthermore, the blood clearance of 57Co-BLM is much more rapid than that of 67Ga-citrate, so that an early study may be performed in a 6-24 hr. interval instead of 48-72 hr. with 67Ga-citrate. 57Co-BLM scintigraphy is an easy, non-invasive and sensible diagnostic technique in determining the extent of malignant tumors in ORL patients.