Refractory response to entrectinib for ROS-1 rearranged NSCLC with concurrent de novo TP53 mutation showing good response to CNS lesion, but poor duration of response: A case report

Entrectinib, a ROS-1 inhibitor, has been shown to be effective for patients with ROS-1 fused NSCLC, and has been established as the standard of care for this population. Entrectinib has been shown to achieve a better response to brain metastasis due to the characteristic of the drug having a weak interaction with P-glycoprotein and, even in prospective studies, the intracranial response is higher. Patients have been known to acquire resistance to molecularly targeted drugs such as EGF-TKIs or ALK-TKIs during targeted therapy. Similarly, the mechanisms of resistance to entrectinib have been reported, but information about the effects of TP53 mutation with entrectinib are still limited. Here, we experienced a case of a patient with ROS-1 fusion and concurrent TP53 mutation who was treated with entrectinib, resulting in a response to brain metastasis but rapid resistance to entrectinib. Our case demonstrates both the intracranial activity of entrectinib and the potential for resistance to entrectinib due to TP53 mutation.

The Potential of Digital Polymerase Chain Reaction for Improving Diagnostic Yield of Nontuberculous Mycobacteria Pulmonary Disease

Introduction

Many patients with nontuberculous mycobacteria pulmonary disease are asymptomatic. The disease diagnosis is confirmed in only a small proportion of patients with radiological findings suspicious for nontuberculous mycobacteria pulmonary disease. Thus, many patients remained undiagnosed. Here, we evaluated the diagnostic value of digital polymerase chain reaction (PCR) in nontuberculous mycobacteria pulmonary disease.

Methods

We prospectively evaluated 123 patients with radiological findings suspicious for nontuberculous mycobacteria pulmonary disease. Digital PCR was performed using bronchial lavage fluid, sputum, saliva, blood, and urine.

Results

The culture of bronchial washing fluid was positive for nontuberculous mycobacteria in 53 patients and negative in 70. The positive detection rate of nontuberculous mycobacteria by digital PCR in patients with positive culture (n = 53) was as follows: bronchial lavage fluid 100%, sputum 62.9%, saliva 41.5%, blood 7.5%, and urine 3.8%. All patients with two or more positive partitions for nontuberculous mycobacteria in the digital PCR of bronchial lavage fluid showed nontuberculous mycobacteria growth in the bronchial lavage fluid culture. The digital PCR analysis of the bronchial lavage fluid showed a high sensitivity (100%), specificity (85.7%), positive predictive value (84.1%), negative predictive value (100%), and a high concordance rate (91.9%) with the bronchial lavage fluid culture results. In addition, the culture of bronchial lavage fluid was positive for nontuberculous mycobacteria in patients with two or more positive partitions in the digital PCR of sputum and saliva with a combined positive predictive value of 81.1%.

Conclusion

Digital PCR analysis of nontuberculous mycobacteria in bronchial lavage fluid shows a high concordance rate with the bronchial lavage fluid culture results and a high positive predictive value using both sputum and saliva, suggesting the potential usefulness of dPCR for diagnosis of nontuberculous mycobacteria pulmonary disease in clinical practice.

Source localization of posterior slow waves of youth using dipole modeling

AIM

Posterior slow waves of youth have a well-known electroencephalographic pattern that peaks in adolescence and usually disappears in adulthood. In general, posterior slow waves of youth are regarded as normal, but some reports have suggested that their presence is related to immature personalities or inappropriate social behavior. The physiological significance of this electroencephalographic pattern, however, remains unclear. The purpose of this study was to investigate the neural origins of posterior slow waves of youth using dipole source modeling.

METHODS

Electroencephalographic epochs, including clear posterior slow waves of youth, were visually selected from electroencephalograms obtained from six normal adolescents using 25 scalp electrodes. The selected epochs were then averaged by arranging the negative peak of the slow waves at the occipital area of each epoch on the time axis. The averaged waveforms consisting of six right and one left posterior slow waves of youth were used for dipole source analysis. A single equivalent current dipole was estimated for the averaged waveforms.

RESULTS

The best equivalent current dipoles were estimated to be located in or around the fusiform and middle occipital gyrus ipsilateral to the posterior slow waves of youth.

CONCLUSIONS

The location of the estimated dipoles of posterior slow waves of youth was on the so-called ventral visual pathway. Further research is required to clarify the physiological significance of posterior slow waves of youth with respect to their origin.

Electroencephalographic dipole source modeling of frontal intermittent rhythmic delta activity

BACKGROUND

Frontal intermittent rhythmic delta activity (FIRDA) on electroencephalography (EEG) consists of a run of rhythmic delta waves with frontal predominance. Although FIRDA is a relatively common abnormal EEG finding, the underlying mechanisms that produce FIRDA remain unclear. The aim of this study was to investigate the cortical source of FIRDA using dipole source modeling.

METHODS

We selected EEG epochs, including typical FIRDAs, from EEG recordings obtained using 25 scalp electrodes on 5 subjects. We averaged these epochs by arranging the negative peaks of the delta waves at the Fp electrodes and estimated dipoles for nine averaged waveforms.

RESULTS

Averaged waveforms were explained by a single-dipole model in seven FIRDAs and by a two-dipole model in the remaining two FIRDAs with high reliability. Estimated dipoles had a radial orientation with respect to the frontal pole and were located in the medial frontal region. The anterior cingulate cortex was the most common dipole location.

CONCLUSIONS

This is the first study to approach the fundamental FIRDA mechanism by dipole source modeling and to clarify that FIRDA may be generated from the medial frontal region, particularly from the anterior cingulate cortex.

Eustachian tube function tests and their diagnostic potential in normal and diseased ears

We have summarized various methods for testing Eustachian tube function since the 1980's. There have been numerous contributions to our knowledge on Eustachian tube and middle ear functions, and the pathophysiology of disorders of the middle ear has been clarified. Understanding of the Eustachian tube function and controlling the Eustachian tube dysfunction are mandatory for adequate clinical management and for improvement of the prognosis.

Tubotympanoplasty

Prognostic value of the Eustachian tube function test remains controversial. To prevent ear drum adhesion or the recurrence of cholesteatoma it is important to select cases with severe organic obstruction of the Eustachian tube and to use surgical procedures to restore function. We summarize here the indications and the surgical procedure for organic obstruction of the Eustachian tube, especially in the region of the tympanic orifice. Adequate preoperative evaluation of Eustachian tube function and pertinent surgical procedures will pave the way for a better prognosis for patients subjected to ear surgery.

Enhanced MRI in patients with Ramsay-Hunt's syndrome

Enhanced MRI was performed in 14 patients with Ramsay-Hunt's syndrome to investigate the pathogenesis of this syndrome. All MRI studies were performed on a 0.5T superconductivity MRI system using a head coil with Gd-DTPA. Enhancement was observed in the areas of the distal internal auditory canal and labyrinthine segment in many patients, and was especially prominent in patients suffering from vertigo, tinnitus, and hearing loss. In some patients it involved not only the facial nerve of the internal auditory canal but also the cochlear nerve and vestibular nerves. Since histological changes of the facial nerve in patients with Ramsay-Hunt's syndrome are assumed to occur in the distal internal auditory canal and labyrinthine segment, which is more proximal than the geniculate ganglion, and the possibility is suggested that inflammation may spread to the vestibular and cochlear nerve via the internal auditory canal.

Active opening function of the human eustachian tube: comparison between sonotubometry and pressure equilibration test

Sonotubometry and pressure equilibration test are representative test methods to evaluate the active opening capacity of the Eustachian tube. We applied these tests to 72 ears with otitis media with effusion and 21 ears with chronic otitis media. In 73 ears, both tests showed identical results (11 ears with good active function and 62 ears with poor function). Twenty ears showed good active opening by sonotubometry despite inability to relieve applied negative pressure by swallowing. This inconsistency is believed to result from a too short duration of the tubal opening, by which sound is transmitted through the Eustachian tube, without pressure change in the middle ear cavity. We propose that sonotubometry is a suitable method of detecting impairment of the tubal active opening function, but that a good result by sonotubometry does not always indicate a satisfactory pressure equilibration capacity of the Eustachian tube.

A possible masking effect of tinnitus. Evaluation of CNV audiometry

To determine whether tinnitus has a masking effect similar to that of general external sounds, the hearing threshold shift when the tinnitus was changed by intravenous administration of lidocaine was measured by contingent negative variation (CNV) audiometry. In a preliminary study, the reliability of CNV audiometry was evaluated in 12 patients with tinnitus. The reproducibility of CNV audiometry was confirmed, based on repeated measurements of CNV audiometry at the tinnitus frequency. The threshold difference between CNV audiometry and pure tone audiometry was -0.76 +/- 1.35 dB, and a high statistical correlation between the threshold of CNV audiometry and pure tone audiometry was evident. The CNV threshold shift at tinnitus frequency after lidocaine injection was measured in 89 ears. In the tinnitus-decreased group, the CNV threshold decreased (4-6 dB) in 22% of cases; however, in the tinnitus-unchanged group, the CNV threshold was little changed. These findings suggest that tinnitus may have a masking effect as is the case with external sounds.

Otitis media with effusion and eustachian tube dysfunction in adults and children

Eustachian tube (ET) function was studied in 162 ears with otitis media with effusion (OME) and chronic otitis media (COM), using tubo-tympanoaerodynamic graphy, patency and pressure equilibration test in the inflation-deflation test. Severe impairment of active opening function was found in both OME children and adults compared with that of COM patients. This impairment in active opening was thought to result from functional obstruction of the ET in 71.8% of OME children and 51.8% of OME adults. However, 45.6% of OME adults had an organic obstruction while such was present only in 28.2% of OME children. We deduce from this study that impaired active opening function of the ET in both OME children and adults is the result of functional obstruction rather than organic obstruction, but organic obstruction is considered to be related to the pathogenesis of OME in adults.

Kinetics of epidermal growth factor in saliva

Human epidermal growth factor (hEGF) stimulates the growth and differentiation of various tissues. We measured EGF levels in saliva (n = 128), urine (n = 94), and serum (n = 99) with radioimmunoassay in order to study the kinetics of hEGF in saliva of normal subjects and patients with oral disease. Salivary EGF levels showed an apparent diurnal rhythm related to the taking of meals. Urinary and serum EGF levels showed no obvious diurnal rhythm. There was no significant correlation between salivary and urinary EGF levels, nor between salivary and serum EGF levels. Salivary EGF levels were significantly lower in the younger group (0-9 years old, 3.06 +/- 0.32 ng/ml, p < 0.05) than in the elder group (10-79 years old, 4.78 +/- 3.5 ng/ml), but did not correlate with age in the elder group. There was no significant difference between males and females between EGF levels in saliva, urine or serum. The relative proportion of EGF levels in submandibular gland saliva, parotid saliva, and whole saliva was 1:6:4. The positive rate of immunohistochemical EGF showed no significant differences between submandibular gland, parotid gland, sublingual gland or minor salivary gland. Salivary EGF levels were markedly low in patients with oral inflammations (stomatitis aphthosa, or peritonsillar abscess) or head and neck tumors (squamous cell carcinoma of the tongue, oral cavity, hypopharynx or larynx). These findings may be significant pathophysiologically. Low salivary EGF levels may reduce the capacity of oral mucosal defense mechanisms to fight against injury by physiochemical agents.

Animal model of otitis media with effusion

A rat model of otitis media with effusion (OME) was developed by intratympanic injection of E. coli endotoxin and section of the third branch of the trigeminal nerve (V3). The period of fluid retention induced by the endotoxin was prolonged for 5 days or longer, in cases when tubal function was impaired by cutting of V3. Three Eustachian tube function tests (patency test of inflation-deflation tests, forced response test and negative pressure test) were carried out before and after the endotoxin inoculation and V3 sectioning. At 4 days after these procedures, passive opening pressure (Po), closing pressure (Pc) and tubal resistance (R2) were significantly lowered. The negative pressure test showed impaired capacity of active opening. This model of Eustachian tube dysfunction is considered to reveal functional obstruction, a condition similar to that of clinical cases of OME. The study shows that both inflammation in the middle ear and tubal dysfunction, such as functional obstruction, are factors in the development and prolongation of OME.

MR imaging of vascular compression in hemifacial spasm

Hemifacial spasm is related to vascular compression of the root entry zone of the facial nerve at the brainstem by elongated tortuous vessels of the vertebrobasilar arterial system. In this study, we performed MR imaging in 16 patients with hemifacial spasm and investigated the vascular structures in bilateral-cerebellopontine angles and the relationship of each vessel to the root entry zone of the facial nerve. MR examination was performed with a 0.5 tesla MRI system, and MR angiography (3D time-of-flight) was obtained. Of 15 patients in whom both the nerve and vessels were clearly visible and could be observed to contact each other at the root entry zone, in 11 the tortuous artery could be identified by name. In only 1 patient was the contact between the nerve and vessel indeterminate, due to nonvisualization of the vessel around the facial nerve at its root entry zone. These findings suggest that MRI is a useful screening method in the preoperative assessment of hemifacial spasm.

Sensation of ear fullness caused by eustachian tube dysfunctions

One hundred and ninety-four patients with a sensation of ear fullness were examined with the audiometry, tympanometry, and tubotympanoaero-dynamic graphy (TTAG) as a eustachian tube ventilatory test. In 74 cases of 194, the eustachian tube dysfunction was thought to cause an ear fullness sensation and patulous tube was found in 19 patients which is more frequent than expected. Functional unbalance of the both eustachian tubes which results from minimum ventilatory disturbance on the complaining side was also thought to be one of the causes of this symptom. The eustachian tube dysfunctions like stenotic or patulous tube could not be fully diagnosed by the audiometry and tympanometry because most patients with the eustachian tube dysfunctions showed normal middle ear pressure measured by the tympanometry. From our study, it could be concluded that eustachian ventilatory test like TTAG was very available in the patient with an ear fullness feeling which is one of the most common symptoms in the otolaryngological field.

Recurrent bacterial meningitis. Secondary to malformation of the inner ear

A 5-year-old girl with congenital sensorial deafness experienced four episodes of bacterial meningitis in a 13-month period. On the fourth episode, an extensive search for the cause of recurrent meningitis was conducted. Complete immunologic studies, humoral, cellular, and phagocytic, yielded negative results. Precise otological examination, i.e., skull roentgenograms, an inner ear target CT scan, and puncture of the eardrum, was attempted, which disclosed the inner ear malformation (Mondini's anomaly) and a cerebrospinal fluid (CSF) fistula. CSF discharge from the oval window was repaired surgically. Extensive otologic evaluation should be conducted in patients with recurrent bacterial meningitis.

Clinical evaluation of S-CMC syrup applied in the treatment of otitis media with effusion. Double blind comparative test with placebo

We carried out a double blind comparative trial with placebo serving as control using 250 cases of infant otitis media with effusion (OME) in order to objectively evaluate the clinical usefulness of S-carboxymethylcysteine (S-CMC), an oral mucolytic agent, against OME. The results obtained were as follows. 1) Global improvement rate, when judged in items of overall improvement, was 79.8% in S-CMC group and 58.2% in placebo group, S group being significantly better when compared to P. 2) The degree of improvement in each item for evaluation revealed significantly better results in S group compared to P, in both objective findings of the effusion amount and its property, and in audiological findings. 3) Adverse reactions observed in 3 cases (2.5%) in S group and in 2 (1.5%) in P group were not serious, and were eliminated through suspension or discontinuation of the medication. The results obtained suggested the usefulness of S-CMC when used in the treatment of OME.

Evaluation of velopharyngeal closure by CT scan and endoscopy

Computerized tomography (CT) and endoscopy were used for the objective evaluation of velopharyngeal closure. In 19 patients with cleft palates and 9 normal subjects, CT scans of the velopharynx were made both at rest and during vowel phonation with a scanning time of 3.0 seconds and slicing width of 3 mm. At the same time, endoscopic observations of the velopharynx through the nose were carried out both at rest and during phonation. CT scan during phonation clearly demonstrated the mobility of the velopharynx, i.e., elevation of the soft palate, inward movement of the lateral pharyngeal walls, and protrusion of the posterior pharyngeal wall, in a single picture. Its disadvantage is exposure to x-rays and a rather complicated procedure. However, endoscopy is simple with no exposure to x-rays, but its disadvantage is occasional incomplete visualization because of the dead angle created by the elevated soft palate. Thus the combined use of CT and endoscopy can help to determine a rational choice of treatment for cleft palates.

Cineroentgenographic and electromyographic studies of Eustachian tube function

To determine the opening and closing process of the Eustachian tube during swallowing, the simultaneous recording of cineroentgenograms and electromyograms (EMG) was carried out in three monkeys. It was revealed that synchronous with the activity of the tensor veli palatini muscle, the cartilaginous tube opened for a very short time (ca. 250 ms) by an outward movement of its lateral wall. On the other hand, the pharyngeal orifice of the tube dilated for a relatively long time synchronous with the activity of the levator veli palatini muscle. These time lags between two parts of the tube seemed to help the pumping function of the tube.

Role of the tensor tympani muscle in eustachian tube function

In order to determine the role of the tensor tympani muscle in Eustachian tube function, pressure changes in the external and middle ear of 13 cats were measured under four experimental conditions. It was revealed that contraction of the tensor tympani muscle during swallowing did not result in any tympanic pressure rise which might assist in tubal ventilation. Acoustic stimulation was then used to measure consistent contraction of the tensor tympani muscle. Combined contraction of the tensor veli palatini and tensor tympani muscle under the condition of positive tympanic pressure failed to open the tube. It was concluded that the tensor tympani muscle might not play any part in tubal function.

Evaluation of Eustachian tube function by contrast roentgenography

Contrast roentgenography and cineroentgenography were carried out on nine patients with perforated eardrums to reveal the opening process of the Eustachian tube and its pumping-like clearance function in human beings. The results were as follows: (1) the tubal lumen opens along the cartilaginous part of the tube owing to the outward displacement of its lateral wall; (2) the pumping function of the tube consists in two phases: accumulation of the fluid in the tube by tensor contraction and discharge of the fluid by tensor relaxation.

Cineradiogrphic analysis of eustachian tube function. Experimental study

In order to determine the effect of muscular contraction upon the opening processes of the eustachian tube, cineradiography of four monkeys' tubes during stimulation of the tensor and levator veli palatini muscles was carried out. Levator stimulation produced no opening of the tube except a dilation of the pharyngeal orifice. On the other hand, tensor stimulation produced a consistent opening of the tube by outward displacement of the tubal wall along its entire cartilaginous part. A marked time lag in the movement of the tube between its proximal (isthmic) and distal (pharyngeal) parts was regarded to be important in the clearance function of the tube.