Perceptions of life and experiences of health care support among individuals one year after head and neck cancer treatment - An interview study

PURPOSE

To examine how individuals treated for head and neck cancer perceive life one year after the end of treatment and how they experience supportive efforts from health care.

METHODS

A semi-structured interview study of 21 patients was performed one year after the end of treatment. The patients gave their views concerning physical, psychological, and return-to-work issues, and their experiences concerning rehabilitative efforts from health care and particularly the contact nurse were captured. A thematic analysis was conducted.

RESULTS

One year after treatment the patients were still suffering from side effects and from fear of recurrence, but they strived to live as they did before the cancer diagnosis, such as having returned to work and resuming leisure activities. Moreover, the rehabilitative efforts from health care had ended. Having access to a contact nurse, also known as a clinical nurse specialist, was positive, however, the participants lacked regular long-term follow-ups with the contact nurse regarding rehabilitation needs. Improvement possibilities were seen in clarifying the role of the contact nurse and that the contact nurse should show engagement and make the initial contact with the patients.

CONCLUSION

Despite the sequelae from treatment, the patients strived to live as before their diagnosis. By regular, engaged, and long-term follow-ups by the contact nurse, remaining needs may be uncovered, and appropriate individualized support and rehabilitation can be offered.

Novel Screening Tool Using Non-linguistic Voice Features Derived from Simple Phrases to Detect Mild Cognitive Impairment and Dementia

Appropriate intervention and care in detecting cognitive impairment early are essential to effectively prevent the progression of cognitive deterioration. Diagnostic voice analysis is a noninvasive and inexpensive screening method that could be useful for detecting cognitive deterioration at earlier stages such as mild cognitive impairment. We aimed to distinguish between patients with dementia or mild cognitive impairment and healthy controls by using purely acoustic features (i.e., nonlinguistic features) extracted from two simple phrases. Voice was analyzed on 195 recordings from 150 patients (age, 45-95 years). We applied a machine learning algorithm (LightGBM; Microsoft, Redmond, WA, USA) to test whether the healthy control, mild cognitive impairment, and dementia groups could be accurately classified, based on acoustic features. Our algorithm performed well: area under the curve was 0.81 and accuracy, 66.7% for the 3-class classification. Thus, our vocal biomarker is useful for automated assistance in diagnosing early cognitive deterioration.

High rate of early recurrence of peritonsillar abscess among adolescents and young adults

BACKGROUND

Peritonsillar abscess (PTA) can be treated with aspiration or incision for drainage, but a subsequent PTA can occur if tonsillectomy is not performed. Better understanding is needed of when tonsillectomy should be performed to avoid PTA recurrence.

OBJECTIVE

This study investigated the recurrence rate of PTA following aspiration or incision for drainage and evaluated the risk factors for recurrence.

METHODS

The medical records of 292 patients treated for PTA were reviewed. Recurrence of PTA and elective or quinsy tonsillectomy were the primary endpoints. A Cox proportional hazards regression model for PTA recurrence was constructed with sex, age, and PTA history as predictors.

RESULTS

Young age was the only significant predictor of PTA recurrence. Patients aged 15 to 24 years had a 30-day recurrence rate of 15.5% and a total recurrence rate of 26.6%. The total recurrence rate among patients over 30 years of age was significantly less at 4.0% (Fisher's exact test, p < .05).

CONCLUSION AND SIGNIFICANCE

Based on our results, tonsillectomy should be considered for PTA patients between 15 and 25 years of age and, to effectively avoid future recurrence of PTA, should be performed urgently.

Unique fiber phenotype composition and metabolic properties of the stapedius and tensor tympani muscles in the human middle ear

The middle ear muscles have vital roles, yet their precise function in hearing and protection remains unclear. To better understand the function of these muscles in humans, the morphology, fiber composition, and metabolic properties of nine tensor tympani and eight stapedius muscles were analyzed with immunohistochemical, enzyme-histochemical, biochemical, and morphometric techniques. Human orofacial, jaw, extraocular, and limb muscles were used as references. The immunohistochemical analysis showed that the stapedius and tensor tympani muscles were markedly dominated by fibers expressing fast contracting myosin heavy chain MyHC-2A and MyHC-2X (79 ± 6% vs. 86 ± 9%, respectively, p = 0.04). In fact, the middle ear muscles had one of the highest proportions of MyHC-2 fibers ever reported for human muscles. Interestingly, the biochemical analysis revealed a MyHC isoform of unknown identity in both the stapedius and tensor tympani muscles. Muscle fibers containing two or more MyHC isoforms were relatively frequently observed in both muscles. A proportion of these hybrid fibers expressed a developmental MyHC isoform that is normally absent in adult human limb muscles. The middle ear muscles differed from orofacial, jaw, and limb muscles by having significantly smaller fibers (220 vs. 360 μm2 , respectively) and significantly higher variability in fiber size, capillarization per fiber area, mitochondrial oxidative activity, and density of nerve fascicles. Muscle spindles were observed in the tensor tympani muscle but not in the stapedius muscle. We conclude that the middle ear muscles have a highly specialized muscle morphology, fiber composition, and metabolic properties that generally showed more similarities to orofacial than jaw and limb muscles. Although the muscle fiber characteristics in the tensor tympani and stapedius muscles suggest a capacity for fast, fine-tuned, and sustainable contractions, their difference in proprioceptive control reflects different functions in hearing and protection of the inner ear.

Carcinomas of the minor salivary glands of the oral cavity. A population-based study from the Swedish Head and Neck Cancer Register for 2008-2018

BACKGROUND AND OBJECTIVES

Carcinomas of the minor salivary glands are rare with a heterogeneous pathology. This study explored the demographics, histology, treatment and survival in the Swedish population over 11 years.

MATERIAL AND METHODS

Cases of salivary gland carcinomas in the oral cavity were extracted from the 'Swedish Head and Neck Cancer Register' (2008-2018). Statistical analyses with cross tabulation, age grouping, chi-square, the Kaplan-Meier method and log-rank tests were performed.

RESULTS

Three hundred thirty cases were included (62% female; mean age 60 years; 83% were WHO Performance Status 0). The carcinomas were mostly stage I (57%), and the most common site was the palate with 165 tumours (50%). The most common histology was mucoepidermoid carcinoma (30%), followed by polymorphous low-grade adenocarcinoma (25%) and adenoid cystic carcinoma (24%). The distribution of histology differed between age groups. The five-year predicted overall survival rate was 83%. Most patients (89%) were treated with primary surgery.

CONCLUSION AND SIGNIFICANCE

The demographics, histology, and survival of minor salivary gland carcinomas in the oral cavity in the Swedish population correspond well with previously published material. The demographics and histology differ from carcinomas of the major salivary glands in the same population.

Forces Required for Isolated Malleus Shaft Fractures

BACKGROUND AND HYPOTHESIS

Isolated malleus shaft fractures are rare cases. A commonly reported cause is a finger pulled out from a wet outer ear canal after a shower or bath. The objective was to investigate experimentally the mechanism and forces needed to establish an isolated malleus shaft fracture.

METHODS

Ten fresh-frozen human temporal bones were adapted to allow visual inspection of the structures involved while negative pressure trauma was applied. Thirty malleus bones were broken and the required forces were measured. Measurements from 60 adult test subjects were used to create mathematical and physical models to calculate and measure the forces necessary for generating trauma. To calculate the maximum muscle force developed by the tensor tympani muscle, the muscle area and fiber type composition were determined.

RESULTS

The temporal bone experiments showed that applied negative pressure in a wet ear canal could not fracture the malleus shaft with only passive counterforce from supporting structures, although the forces exceeded what was required for a malleus shaft fracture. When adding calculated counteracting forces from the tensor tympani muscles, which consisted of 87% type II fibers, we estimate that a sufficient force is generated to cause a malleus fracture.

CONCLUSION

The combination of a negative pressure created by a finger pulling outward in a wet ear canal and a simultaneous counteracting reflexive force by the tensor tympani muscle were found to be sufficient to cause an isolated malleus fracture with an intact tympanic membrane.

High prevalence of pharyngeal bacterial pathogens among healthy adolescents and young adults

The pharyngeal mucosa can be colonized with bacteria that have potential to cause pharyngotonsillitis. By the use of culturing techniques and PCR, we aimed to assess the prevalence of bacterial pharyngeal pathogens among healthy adolescents and young adults. We performed a cross-sectional study in a community-based cohort of 217 healthy individuals between 16 and 25 years of age. Samples were analyzed for Group A streptococci (GAS), Group C/G streptococci (SDSE), Fusobacterium necrophorum, and Arcanobacterium haemolyticum. Compared to culturing, the PCR method resulted in more frequent detection, albeit in most cases with low levels of DNA, of GAS (20/217 vs. 5/217; p < 0.01) and F. necrophorum (20/217 vs. 8/217; p < 0.01). Culturing and PCR yielded similar rates of SDSE detection (14/217 vs. 12/217; p = 0.73). Arcanobacterium haemolyticum was rarely detected (3/217), and only by PCR. Overall, in 25.3% (55/217) of these healthy adolescents and young adults at least one of these pathogens was detected, a rate that is higher than previously described. Further studies are needed before clinical adoption of PCR-based detection methods for pharyngeal bacterial pathogens, as our findings suggest a high incidence of asymptomatic carriage among adolescents and young adults without throat infections.

Return to work after oropharyngeal cancer treatment-Highlighting a growing working-age population

BACKGROUND

To describe the frequency of patients returning to work after treatment for oropharyngeal cancer and to identify predictors and physical barriers that might interfere with the return to work process.

METHODS

Cross-sectional study including 295 patients. Data were collected regarding work/sick leave situation at 1 month before diagnosis and 15 months after diagnosis. The situation before diagnosis was retrospectively recalled by the patients. Two subscales and two single items from the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-H&N35 were used. Data were analyzed with multivariate logistic regression.

RESULTS

Fifteen months after diagnosis, 212 patients (72%) were working. To be working 15 months after diagnosis was associated with working before diagnosis. Swallowing difficulties, problems talking on the telephone, and physical appearance were negatively associated with returning to work.

CONCLUSIONS

The large number of individuals returning to work is encouraging for patients diagnosed with oropharyngeal cancer.

When Maxillary Sinusitis Does Not Heal: Findings on CBCT Scans of the Sinuses With a Particular Focus on the Occurrence of Odontogenic Causes of Maxillary Sinusitis

Objectives

This study sought to investigate the proportion of patients with suspected sinusitis referred for radiological examination who have radiologically verified sinusitis of odontogenic origin and to describe this type of sinusitis.

Study Design

This investigation is a retrospective study.

Methods

A total of 303 sinus examinations involving cone beam computed tomography (CBCT) performed at Sunderby Hospital, Luleå, Sweden in 2012 were independently reviewed by two radiologists. The number of cases of maxillary sinusitis and the correlation between maxillary sinusitis and odontogenic infections were determined.

Results

Overall, 24% of the verified cases of sinusitis were odontogenic. An odontogenic origin was identified in 40% of unilateral maxillary sinusitis cases but only 6% of bilateral maxillary sinusitis cases (p = 0.0015). Forty-nine out of 54 patients with periapical destruction had adjacent mucosal swelling in the maxillary sinus, but only 15 of these patients satisfied the criteria for sinusitis.

Conclusion

The present study confirms the close relationship between odontogenic infections and unilateral maxillary sinusitis. Level of Evidence 4.

Prevalence of Fusobacterium necrophorum in tonsils from patients with chronic tonsillitis

CONCLUSION

There was a high prevalence of Fusobacterium necrophorum (FN) in patients with chronic tonsillitis in the age group 15-23 years. This indicates that FN might play an important role in the pathogenesis of chronic tonsillitis in this age group, which is also the age group in which chronic or recurrent tonsillitis is most common.

OBJECTIVES

The role of FN in patients with acute and chronic tonsillitis is unclear. Thus, this study investigated the occurrence of FN in tonsils of patients with chronic tonsillitis. The aim of the study was to determine the prevalence of FN in patients that underwent tonsillectomy due to chronic tonsillitis. This study also investigated if FN was found at different areas in the tonsils.

METHOD

One hundred and twenty-six consecutive patients undergoing tonsillectomy due to chronic tonsillitis were included from the ENT clinics at Sunderby Hospital and Gällivare Hospital, Sweden. Both children and adults were included to encompass various age groups (age =2-57 years). Culture swabs were taken from three different levels of the tonsils - the surface, the crypts, and the inner core of the tonsils. Selective agar plates for detecting FN were used for culture. Culture was also made for detecting β-hemolytic streptococci, Haemophilus influenzae, and Arcanobacterium.

RESULTS

FN was the most common pathogen (19%). The highest prevalence of FN was found in the age group 15-23 years (in 34% of the patients). FN was detected both at the surface and in the core of the tonsils. Furthermore, in the few patients where FN was not detected in all three areas, FN was always detected at the tonsillar surface, in spite of being an anaerobic bacterium. Streptococci group G and C also occurred most frequently (30%) in the same age group as FN (15-23 years), whereas Streptococci group A was more evenly spread among the age groups.

The Gelfoam® plug: an alternative treatment for small eardrum perforations

AIM

To examine if a Gelfoam® plug in combination with surgical removal of the perforation edges could be an alternative to the widely accepted fat plug treatment for smaller ear drum perforations.

MATERIALS AND METHODS

A prospective study of 17 consecutive patients with persistent small ear drum perforations considered for myringoplasty. The perforations were central perforations 2 to 4 mm in diameter. Patient ages ranged from 6 to 83 years, and the operation was performed under general anesthesia with mask ventilation in children and under topical local anesthesia in adults. A Gelfoam® plug was inserted into the perforation after surgical removal of the perforation edges. The follow-up time was more than 3 months.

RESULTS

The closure rate of the ear drum was 83% (15/18). Pure tone average (PTA) was 19 dB preoperatively and 16 dB postoperatively.

CONCLUSIONS

We show for the first time in humans that a Gelfoam® plug in combination with surgical removal of the perforation edges seems to result in about the same closure rate as the fat plug technique in persistent small ear drum perforations. Moreover, the method using Gelfoam® is simpler and faster than the fat plug technique. We suggest that randomized studies comparing the Gelfoam® plug technique with the fat plug technique should be performed.

Reduced expression of Sytl 1 and Ccdc21 and impaired induction of Mt I by oxidative stress in SII-K1 knockout mice

SII-K1 is a member of the transcription elongation factor S-II family. In the mouse, SII-K1 is expressed exclusively in the liver, kidney, heart, and skeletal muscle. Here, we report that deletion of the SII-K1 gene in mice resulted in the downregulation of the synaptotagmin-like 1 (Sytl 1) gene in liver and of the coiled-coil domain-containing 21 (Ccdc21) gene in liver and kidney. Moreover, the induction of the metallothionein I (Mt I) gene in SII-K1-deficient mice liver was impaired in diethyl maleate-induced oxidative stress conditions. Our results suggest that SII-K1 regulates these genes in vivo.

Self-inflicted negative pressure of the external ear canal: a common cause of isolated malleus fractures

We report the investigation of the cause of isolated malleus fractures based on four recent patients at our clinic and five patients reported to us by Swedish otosurgeons. In recent years we have treated four patients with isolated malleus fractures. Colleagues in the Swedish Society of Otosurgeons were encouraged to send us reports on patients with diagnosed isolated malleus fractures, resulting in five more cases. A literature review focusing on the cause and management of this injury was also conducted. Eight of nine patients in the Swedish material had the same history. The patients had inserted a finger into the external auditory canal (most often after a bath) and then pulled it out. Immediately afterwards they experienced a short pain and a hearing loss. An audiogram revealed a conductive hearing loss. After exploration of the middle ear, the most common operation performed was ossiculoplasty. In the present material the most common cause of isolated malleus fractures was a sudden negative pressure in the external auditory canal created by a quick outward movement of a finger in the external ear canal. Since this fracture appears to be infrequent, it can easily be missed at otomicroscopic examination. Tympanometry and pneumatic otomicroscopy are helpful diagnostic tools.

[Thoracic aortic rupture resulting from methicillin-resistant Staphylococcus aureus infection: report of a case]

We report a successful surgical treatment of an aortic arch rupture caused by methicillin-resistant Staphylococcus aureus (MRSA) infection in a 72 years old man who had back pain and hemoptysis as symptoms. Computed tomography showed enlargement of the aortic arch within just 4 days. We diagnosed the state of impending rupture of inflammatory aneurysm and performed emergent operation. The upper lobe of the left lung adhered firmly to the site of rupture and sealed as the barrier to prevent bleeding. The aorta was replaced with a dacron graft in situ after entire resection of infected tissue and sufficient irrigation of the pleural cavity. The patient was treated with vancomycin and minocyclin for MRSA infection. The postoperative course of the patient was uneventful. This suggests that an early operation and a proper use of antibiotics lead to a successful clinical result in patient with infectious aortic rupture.

[Use of multidetector-row computed tomography in a patient with completely obstructed left anterior descending artery]

Multidetector-row computed tomography (MDCT) is a useful diagnostic procedure prior to coronary artery bypass grafting (CABG) as it visualizes the coronary artery less invasively, with higher negative predictive value and lower cost compared with standard coronary angiography (CAG). We recently experienced a case in which the left anterior descending artery (LAD) occlusion prevented CAG evaluation of peripheral vascular status and percutaneous coronary intervention (PCI) or CABG could not be indicated by CAG, whereas MDCT demonstrated a patency of the peripheral LAD. An off-pump coronary artery bypass surgery was performed based on the MDCT findings, and the intraoperative findings were essentially consistent with the MDCT findings. Our experience in this case suggests that the indication for CABG may be accurately judged by using high-resolution MDCT in cases in which CABG graftability may not be judged by CAG.

Alloiococcus otitidis--otitis media pathogen or normal bacterial flora?

During the last decade a new potential otitis media pathogen, Alloiococcus otitidis, has been studied. It is still not clear whether this bacterium really is a pathogen, although it has been found in a high percentage of middle ear effusions in children. The present study aimed to investigate the presence of A. otitidis in the nasopharynx and outer ear canals, and to develop a culture method that would make it possible to isolate A. otitidis from these locations. Nasopharyngeal samples (n = 129) from children below 6 years were investigated by conventional culture on blood agar plates with 6% saline and rabbit antisera against A. otitidis, and by a PCR method. In the same way, we investigated 10 samples from vestibulum nasi of healthy persons, 68 samples from outer ear canals of patients with acute or chronic ear problems, and 24 samples from outer ear canals of healthy persons. In a rat model of acute otitis media, we instilled living A. otitidis into rat middle ears through the tympanic bulla and evaluated the outcome clinically by otomicroscopy at days 3, 6 and 14. Of the 129 nasopharyngeal cultures, 9 were positive for A. otitidis by PCR, but none by the culture method. Of the 68 samples from patients with running ears, 4 were positive for A. otitidis by PCR, but none by the culture method. Of the 24 healthy ear canals, 7 were positive for A. otitidis by PCR and 3 of them also by the culture method. No A. otitidis could be found from the vestibulum nasi. The rat experiment showed that the reactions in the middle ears were mild; we could not provoke a purulent acute otitis media in any of the rats. There was a 7% prevalence of A. otitidis in children below 6 years. The highest prevalence (29%) was found in outer ear canals of healthy persons, which strongly suggests that A. otitidis is part of the normal bacterial flora of the outer ear canal. The doubtful pathogenicity is also confirmed by the fact that--in the rat model--A. otitidis elicited only a mild response in the middle ear. It was possible to isolate A. otitidis using a blood agar plate with 6% saline.

S-II mediated gene regulation

S-II, also designated as TFIIS, was the first identified transcription elongation factor and is widely found in eukaryotes. Among known elongation factors, S-II has a characteristic biochemical activity: it facilitates the elongation process by allowing RNA polymerase II (RNAPII) to read through transcriptional blocks in vitro. While the biochemical and molecular mechanism of stimulating elongation in vitro has been shown in detail, the in vivo role of S-II long remained unclear. Recent research has revealed that S-II has a crucial role in the activation of expression of a set of genes in vivo. In this review, we summarize recent studies focusing on the regulation of gene expression by S-II and discuss the biological functions of S-II.

A daily nasal spray with saline prevents symptoms of rhinitis

OBJECTIVE

To ascertain whether a daily nasal spray with physiological saline could prevent symptoms of common cold in a population of otherwise healthy adults.

MATERIAL AND METHODS

This was study involving 10 weeks of daily use of a nasal saline spray and 10 weeks of only recording symptoms. Young adults eligible for military service at an army barrack in Boden, Sweden were invited to participate in the study and 108 healthy conscripts aged approximately 20 years agreed to do so. Data were recorded by the participants in a diary at home. In the diary the participants noted symptoms such as rhinitis, blocked nose, cough, fever and sore throat (pharyngeal pain). They also recorded inability to perform their duties due to the symptoms, and any medication or antibiotics necessitated by upper respiratory tract infection.

RESULTS

A total of 69 subjects completed the 20-week diary period. For 60 of them, compliance during the spray period exceeded 60% and their data were used in the statistical calculations. During the spray period the number of days with nasal secretion and/or blocked nose (mean 6.4 days) was significantly (p=0.027) lower than that during the observation period (mean 11 days). Furthermore, the participants had a mean of 0.7 episodes of upper respiratory tract infection during the spray period, compared with 1.0 episodes during the observation period (p=0.05).

CONCLUSION

A daily nasal spray with saline can prevent nasal symptoms of common cold in a population of otherwise healthy adults.

[Infant case and adult case of scimitar syndrome with lung sequestration]

We present 2 cases of Scimitar syndrome with lung sequestration, 1 of which is infant case and the other is adult. A 3-month-old baby was transferred to our hospital because of severe heart failure. Cardiac ultrasonography and angiography revealed atrial septal defect and lung sequestration. Because of critical condition, she underwent emergency operation. After the operation of abnormal lung resection, her general condition improved. We emphasize that the prognosis is influenced by operation timing. A 20-year-old female was admitted for atrial septal defect. We diagnosed Scimitar syndrome and lung sequestration as the result of close examinations. We carried out definitive operations of the closure of atrial septal defect, the correction of partially anomalous pulmonary venous return and the resection of malformed lung. This adult case is popular one of Scimitar syndrome.

Is hydrogen peroxide responsible for the inhibitory activity of alpha-haemolytic streptococci sampled from the nasopharynx?

OBJECTIVE

The inhibitory effect of alpha-haemolytic Streptococci (AHS) in vitro on the three commonest otitis media pathogens, Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis, was previously investigated. The aim of this study was to determine the mechanism of this inhibitory activity.

MATERIAL AND METHODS/RESULTS

When fractions of AHS filtrate were assayed to determine their inhibitory activity after size-exclusion chromatography, the inhibitory activity was found in the fractions with a low molecular weight. The inhibitory effect was completely reversed when catalase was added to the cell-free filtrate of AHS. A quantitative method also revealed high production (approximately 3 mmol/l) of hydrogen peroxide in the AHS filtrate with the best inhibitory activity. Electron microscopy of bacteria exposed to AHS filtrate with an inhibitory effect showed changes similar to bacteria exposed to hydrogen peroxide.

CONCLUSIONS

We conclude that the inhibitory effect of AHS is most likely due to the production of hydrogen peroxide. The significance of hydrogen peroxide production of AHS is discussed in relation to the non-specific and specific mucosal defence systems.

Genetic susceptibility to thymic lymphomas and K-ras gene mutation in mice after exposure to X-rays and N-ethyl-N-nitrosourea

PURPOSE

Ras activation is one of the major mechanisms for the development of murine thymic lymphomas by radiation and chemical carcinogens. To gain insight into the relationship between genetic susceptibility and ras gene mutation, the frequency and spectrum of ras gene mutation was examined in thymic lymphomas from susceptible and resistant mice.

MATERIALS AND METHODS

K- and N-ras mutations in thymic lymphomas that arose in X-ray-irradiated and N-ethyl-N-nitrosourea (ENU)-treated mice of susceptible C57BL/6, rather resistant C3H and their hybrid B6C3F1 were analysed by polymerase chain reaction-single-strand conformation polymorphism and subsequent DNA sequencing.

RESULTS

C57BL/6 exhibited a higher incidence of thymic lymphomas after exposure to X-rays and ENU than C3H, with B6C3F1 being intermediate. K-ras gene mutations occurred frequently in the pathogenesis of ENU-induced thymic lymphomas in susceptible C57BL/6 as opposed to resistant C3H. The ras mutations were more frequent in ENU-induced thymic lymphomas than X-ray-induced thymic lymphomas, and with the latter, there was no clear evidence for strain differences, suggesting that the genetic susceptibility to X-rays was independent of ras activation. The mutations of K-ras in thymic lymphomas from C57BL/6 were predominantly GGT to GAT in codon 12, whereas this mutation type was never found in those from C3H. No strain difference was observed in the nucleotide sequence or expression levels of O(6)-alkylguanine alkyltransferase, indicating that this enzyme did not account for the genetic susceptibility to ras activation.

CONCLUSIONS

The results indicate that there is a clear strain and carcinogen dependency of K-ras mutation and that the frequency of ras mutation might determine the genetic susceptibility to ENU-induced lymphomagenesis, whereas pathways independent of ras activation might determine the susceptibility to X-ray-induced lymphomagenesis.

Bacterial adherence to pharyngeal cells: in vitro studies with alpha-haemolytic streptococci and Haemophilus influenzae

We examined the adherence to pharyngeal cells of alpha-haemolytic Streptococci (AHS) and Haemophilus influenzae, representing normal flora and otitis media (OM) pathogens, respectively. The bacteria were incubated with epithelial cells brushed from the tonsils, adenoid or tubal orifice of children and adults. Adherence varied among the clinical isolates of AHS and H. influenzae. AHS adhered better to epithelial cells from a child compared with those sampled from an adult. The bacteria adhered better to cells from the tubal orifice compared with those sampled from the adenoid. The selective attachment of AHS to certain cells but not to others could not be correlated to apoptotic/necrotic cells versus viable cells. Incubation of epithelial cells with an isolate of AHS with good inhibitory activity against OM pathogens showed almost no adherence of bacteria to the epithelial cells after 12 and 24 h of incubation. If, however, an isolate of AHS with weak inhibitory activity was incubated with the cells, the bacteria that were attached to the epithelial cells from the beginning showed overgrowth in the broth and increasing attachment to the cells after 12 and 24 h. Thus the inhibitory activity of AHS could also affect the adherence of potential pathogens to the mucosal surfaces. The adherence pattern may at least partially explain the difference in susceptibility to OM between children and adults.

A nasal spray with alpha-haemolytic streptococci as long term prophylaxis against recurrent otitis media

Previous studies have shown that children with recurrent acute otitis media (rAOM) have significantly lower quantities of alpha-haemolytic streptococci (AHS) in the nasopharynx than healthy children. Furthermore children with otitis media have AHS with lower inhibitory activity in vitro on Streptococcus pneumoniae and non-typable Haemophilus influenzae compared with healthy children. A randomised, placebo controlled and double blind clinical study among children with rAOM was designed to determine whether or not a nasal spray, containing AHS with very good inhibitory activity on the three most common OM pathogens, could be an alternative to tympanostomy tube insertion. Forty three children under 4 years of age were included in the study. The children sprayed once daily for 4 months and were monitored for 6 months. Sixteen children in the active group and 20 children in the placebo group were evaluated. The result showed no significant differences regarding the number of episodes of AOM, with seven recurrences in the active group and eight in the placebo group. No significant changes of the nasopharyngeal flora could be detected during the study period regarding the OM pathogens. Nasal spray according to the performed schedule is not yet an alternative to tympanostomy tubes in children with rAOM. The possibility of increasing the efficacy of this ecological treatment, by using pre-treatment antibiotics, more adhesive bacteria and alternative treatment schedules is discussed.

Bacterial interference between pathogens in otitis media and alpha-haemolytic Streptococci analysed in an in vitro model

Bacterial interference studied by means of agar methods has shown a decreased number of inhibitory alpha-haemolytic Streptococci among otitis-prone children. Additional information was gained regarding the interplay between alpha-haemolytic Streptococci (AHS) and otitis media (OM) pathogens by comparing the bacterial interference in broth with the interference activity studied using agar overlay methods. We found, that non-typeable Haemophilus influenzae (NTHI) and Moraxella catarrhalis are readily inhibited by AHS in broth. Streptococcus pneumoniae was more bacteriostatically inhibited. If two OM pathogens were inoculated simultaneously, an isolate of AHS with poor inhibitory activity was not able to inhibit the growth, in contrast to an isolate of AHS with good inhibitory activity. The initial amount of AHS inoculated with M. catarrhalis seemed to play a decisive role with respect to the inhibitory activity. M. catarrhalis developed reduced susceptibility against AHS both in vivo and in vitro. In vivo studies showed that children with secretory otitis media had fewer isolates of AHS in their nasopharynx with the ability to inhibit all the test pathogens than healthy children (p < 0.001). Although the factor(s) responsible for the inhibitory activity have thus far not been defined, we could exclude low pH and nutrition depletion as the inhibitory mechanism of AHS with good inhibitory activity.

Increased base change mutations at G:C pairs in Escherichia coli deficient in endonuclease III and VIII

Various types of mutation induced by oxidative DNA damage, induced by hydrogen peroxide and riboflavin photosensitization, were determined in Escherichia coli (E. coli) mutants deficient in endonuclease III (endo III) and endonuclease VIII (endo VIII). The majority of hydrogen peroxide-induced and spontaneous mutations consisted of G:C to A:T and to T:A base changes, shown on the mutation assay system by a reversion at a specific site of the lacZ gene. Base changes were also localized at G:C pairs in the mutation of the supF gene, induced by riboflavin photosensitization, which specifically yields 7,8-dihydro-8-oxoguanine (8-oxoG). G:C to T:A and to C:G transversions dominated in both mutants. These results suggest that endo III and endo VIII are involved in the repair of oxidative lesions of guanine.

[Check ups after acute otitis media should be revised. What are we looking for and why?]

The latest Swedish consensus conference (May 2000) on treatment of acute otitis media (AOM) states that a check-up should be made three months after an episode of AOM. In order to find out how these recommendations are implemented 36 general practitioners were asked about their management of AOM check-ups. Almost all GPs checked children below 5 years of age by otoscopy but only 66 percent checked the mobility of the tympanic membrane. The follow-up procedure varied considerably. In a study of 129 ears (99 children) three months after an episode of AOM the diagnostic accuracy of pneumatic otoscopy, tympanometry and audiometry performed at a health care center was studied. The tympanometry performed by a nursing assistant had a very high sensitivity (93 percent) regarding secretory otitis media and could be used as a check-up after AOM. Thus there seems to be no need for the GP to examine ears where tympanometry is normal, but concentrate on the cases with pathologic tympanometry.

A case of papillary muscle rupture caused by acute myocardial infarction

A 63-year-old female was admitted because of cardiogenic shock due to complete rupture of the posterior papillary muscle. The diagnosis was made by echocardiography. She was treated successfully by an emergency replacement of the mitral valve. Early diagnosis and surgical treatment are mandatory and life-saving in the case of complete papillary muscle rupture.

Inhibition of OM pathogens by alpha-hemolytic streptococci from healthy children, children with SOM and children with rAOM

The present study was undertaken to elucidate the inhibitory activity of the normal nasopharyngeal flora against the three most common otitis media (OM) pathogens in healthy children, children with secretory otitis media (SOM) and children with recurrent otitis media (rAOM). Isolates of alpha-hemolytic streptococci (AHS) and OM pathogens were recovered from the tubal orifice in each child. The samples were taken from 20 healthy children under general anesthesia, from 19 children with SOM and 20 children with rAOM. The method used to test the bacterial interference in vitro was a modified agar overlay method. The AHS sampled from the tubal orifice of the healthy children were able to inhibit 92% of the S. peumoniae isolates, 74% of the non-typable H. influenzae isolates and 89% of the M. catarrhalis isolates. The corresponding figures for children with SOM and children with rAOM were: 73% of the S. pneumoniae isolates, 58 and 54% of the non-typable H. influenzae isolates and 86 and 89% of the M. catarrhalis isolates. The AHS from children with SOM and children with rAOM were significantly less capable of inhibiting the S. peumoniae and the H. influenzae isolates (P<0.001). There was no significant difference between the three groups of children regarding inhibitory activity against M. catarrhalis. The results suggest that the inhibitory activity of the normal bacterial flora at the tubal orifice against pneumococci and H. influenzae may be reduced in children with SOM and rAOM.

Synthesis of 9Z-9-substituted retinoic acids by palladium catalyzed coupling reaction of a vinyl triflate with alkenyl stannanes

Palladium catalyzed cross coupling reactions of a vinyl triflate intermediate and various alkenyl stannanes afforded trisubstituted Z-olefins stereoselectively in high yields. These olefins were then converted to the corresponding 9Z-retinoic acids via Horner-Emmons reaction and subsequent basic hydrolysis in excellent yields.

Substrate specificity of human methylpurine DNA N-glycosylase

The activity of human methylpurine DNA N-glycosylase (hMPG) for major substrates was directly compared using two types of substrates, i.e., natural DNA and synthetic oligonucleotides. By the use of ARP assay detecting abasic sites in DNA, we first investigated the activity on the natural DNA substrates containing methylpurines, ethenopurines, or hypoxanthine (Hx) prepared by the conventional methods. After the treatment with hMPG, the amount of AP sites in methylated DNA was much higher than that in DNA containing ethenopurines or Hx. The oligodeoxynucleotide having a single 7-methylguanine (7-mG) was newly synthesized in addition to 1, N(6)-ethenoadenine (epsilonA)-, Hx-, and 8-oxoguanine-containing oligonucleotides. 7-mG was effectively excised by hMPG, though it might be less toxic than the other methylated bases with respect to mutagenesis and cell killing. The kinetic study demonstrated that k(cat)/K(m) ratios of the enzyme for epsilonA, Hx, and 7-mG were 2.5 x 10(-3), 1.4 x 10(-3), and 4 x 10(-4) min(-1) nM(-1), respectively. The oligonucleotides containing epsilonA effectively competed against 7-mG, while Hx substrates showed unexpectedly low competition. Concerning the effect of the base opposite damage, hMPG much preferred Hx.T to other Hx pairs, and epsilonA.C and epsilonA.A pairs were better substrates than epsilonA.T.

Delayed transfection of DNA after riboflavin mediated photosensitization increases G:C to C:G transversions of supF gene in Escherichia coli mutY strain

We have previously reported that the majority of base substitution mutations of the Escherichia coli supF gene induced by riboflavin mediated photosensitization were G:C to C:G changes, in addition to G:C to T:A changes which were probably caused by 8-hydroxyguanine (oh(8)Gua), in wild type and mutM mutator mutant strains. This implies that lesions other than oh(8)Gua are produced by riboflavin-photosensitization. G:C to C:G base substitutions have been found in the mutations induced by ionizing radiation and reactive oxygen species, as well as spontaneous mutation. To characterize the G:C to C:G mutation, riboflavin- photosensitized plasmid DNA carrying the supF gene was left at room temperature for 5 h in the dark before transfection. The delayed transfection gave a mutational spectrum different from that for immediate transfection. G:C to C:G transversions significantly increased in mutY mutator strain, in which the transversion was not detected in the immediate transfection. Lesions causing G:C to C:G changes increased during 5-h holding after photosensitization and MutY protein presumably takes part in this type of base change mutation.

In vitro inhibition of S. pneumoniae, nontypable H. influenzae and M. catharralis by alpha-hemolytic streptococci from healthy children

The present study aimed to investigate the inhibitory activity of the normal epipharyngeal flora against the three most common acute otitis media (AOM) pathogens in healthy children, and to study if the inhibitory activity differs between alpha-hemolytic streptococci (AHS) sampled from the tubal orifice and from those sampled from the adenoid. A total number of ten isolates of AHS were collected from the tubal orifice and the adenoid, respectively, in ten children undergoing adenoidectomy or tonsillectomy. None of the children had a history of otitis media, neither secretory otitis media (SOM) nor AOM. The method used to test the bacterial interference in vitro was a modified agar overlay method. The results showed that the AHS from nasopharynx were able to inhibit the majority of the S. pneumoniae, nontypable Haemophilus influenzae and Moraxella catharralis isolates tested. The AHS isolates from the tubal orifice inhibited growth of 93% of S. pneumoniae, 79% of H. influenzae and 84% of M. catharralis isolates. The corresponding figures among isolates from the adenoid were 76, 48 and 62%. This difference in the inhibitory capacity between the AHS isolates collected from the adenoid, compared with the AHS collected from the tubal orifice, is statistically significant (P<0.01) and implies that it is important to know the exact sampling locality before conclusions are made concerning the significance of bacterial interference in the upper airways.

Activation of human O6-methylguanine-DNA methyltransferase gene by glucocorticoid hormone

O6-methylguanine-DNA methyltransferase (MGMT), a ubiquitous DNA repair protein, removes the mutagenic DNA adduct O6-alkylguanine, which is synthesized both endogenously and after exposure to alkylnitrosamines and alkylating antitumor drugs such as 2-chloroethyl-N-nitrosourea (CNU). The MGMT gene is highly regulated in mammalian cells and its overexpression, observed in many types of tumor cells, is often associated with cellular resistance to CNU. Dexamethasone, a synthetic glucocorticoid hormone, was found to increase MGMT expression in HeLa S3 cells, concomitant with their increased resistance to CNU. Two putative glucocorticoid responsive elements (GREs) were identified in the human MGMT (hMGMT) promoter. Transient expression of the luciferase reporter gene driven by an hMGMT promoter fragment containing these GREs was activated by dexamethasone. DNase I footprinting assays demonstrated the binding of glucocorticoid receptor to these sequences. In vitro transcription experiment showed that these DNA sequences are functional in glucocorticoid receptor signal-mediated activation of transcription. These results suggest glucocorticoid-mediated induction of the MGMT gene contributes to high level expression of MGMT.

The bioavailability of magnesium from Wakame (Undaria pinnatifida) and Hijiki (Hijikia fusiforme) and the effect of alginic acid on magnesium utilization of rats

The bioavailability of magnesium from Wakame and Hijiki, and the effects of alginic acid on absorption of dietary magnesium were examined in five groups of rats fed either control, Wakame, Hijiki, AW (containing the same amount of alginate as in the Wakame) and AH (containing the same amount of alginate as in the Hijiki) diets, and animals fed a low magnesium diet (LMg) (twentieth amount of magnesium in the original mineral mixtures as the control). Food intake and body weight gain were decreased by adding sodium alginate to the diets. A large amount of calcium accumulated only in the kidneys of the rats fed the LMg diet. Serum magnesium concentration decreased only in the LMg group. The magnesium content in the defatted left femurs did not differ between the control and Wakame fed animals and also among the animals eating Wakame, Hijiki and AW diets. The breaking force of the right femurs did not differ among all the groups except the LMg group. The ratio of apparent magnesium absorption (%) of the control, LMg, Wakame, Hijiki, AW and AH groups was 82.2, 72.7, 66.9, 50.8, 69.3 and 54.2 in the first experimental period, and was 75.3, 52.1, 57.7, 46.9, 62.6 and 60.5 in the second experimental period, respectively. It was clear that the bioavailability of magnesium in the Wakame fed rats was higher than in those eating the Hijiki. Large amounts of sodium alginate lowered magnesium absorption from the diet.

Specificity of mutations induced by riboflavin mediated photosensitization in the supF gene of Escherichia coli

Riboflavin-mediated photosensitization has been shown to produce 8-hydroxyguanine (oh8Gua) in DNA. We investigated the specificity of mutation of photosensitized supF gene induced in Escherichia coli. The oh8Gua repair deficient E. coli mutant mutM and mutY were transformed with plasmid pUB3 carrying the supF gene irradiated with white light in the presence of riboflavin. Under these conditions, riboflavin photosensitization increased the amounts of oh8Gua in pUB3 DNA. Three types of a single base substitution occurring at G:C pairs were detected in both wild-type and mutM mutant strains. Almost all base substitutions were transversions to T:A or C:G pairs occurring at a similar extent in both wild-type and mutM strains. Mutations derived from mutY strain transformed with photosensitized DNA were only G:C to T:A transversions. These G:C to T:A transversions observed in the mutY strain were suggested to be the result of mispairing of oh8Gua with adenine. Riboflavin-mediated photosensitization may also produce lesions on DNA causing G:C to C:G changes by unknown mechanisms.

Establishment and characterization of a hypocatalasemic mouse cell strain

Contact-inhibited catalase-deficient fibroblast cell strain has been established from the homozygous hypocatalasemic C3H/Csb mutant mouse. This cell strain has low level of catalase enzyme activity and has normal level of enzyme activities of both glutathione peroxidase and superoxide dismutase. Catalase-deficient C3H/Csb mutant cell strain is markedly more sensitive to the toxicity of hydrogen peroxide compared to wild-type C3H/Csa cell strain. In addition, mutant cell strain is sensitive to X-rays and near-UV compared to wild-type cell strain, but shows the same sensitivities to topoisomerase II inhibitors, adriamycin and 4'-(9-acridinylamino) methanesulfon-m-anisidide (m-AMSA), and the DNA cross-linking agents, cisdiamminedichloroplatinum (II) (cis-Pt) and trans-diamminedichloroplatinum (II) (trans-Pt). These cell strains will be of use in the study of the roles which catalase plays in the intracellular prevention of DNA damage induced by oxidative stress.

Changes in plasma free and sulfoconjugated catecholamines during the perioperative period of cardiac surgery: effect of continuous infusion of dopamine

In order to elucidate the pharmacological properties of the formation of sulfoconjugated catecholamines (CAs) in human plasma, we investigated the changes in the plasma levels of free and sulfoconjugated CA during the continuous infusion of dopamine (DA; 4-6 microg/kg/min for 24 h, followed by 3-4 microg/kg/min for 48 h) in patients who had undergone cardiac surgery. The plasma level of free DA increased immediately after the start of the infusion and reached a plateau within 1 h at a level of about 2000 times the basal value. In the control patients who had received non-cardiac surgery without DA infusion, plasma-free DA increased only 5-fold after their operation. The plasma level of DA sulfate increased linearly for 24 h, to 48-fold of the basal value by DA infusion, whereas it showed only a 2-fold increase in the control patients. After 24 h, due to reduction of the infused DA dose, the level of free DA gradually decreased, whereas the level of DA sulfate remained elevated. The plasma levels of free adrenaline (Ad) and noradrenaline (NA) also increased during the DA infusion, but their levels reached a plateau within 1-2 h. Sulfoconjugated Ad and NA increased progressively until the tapering off of DA infusion. In the control patients, both free and conjugated Ad and NA showed transient increases over 12 h after surgery. These results suggest that sulfoconjugation plays a role in regulating the plasma levels of excess free CA, thereby modifying the cardiovascular effects of circulating CA. Measurement of the increase in plasma conjugated CA may be useful as an index of the increase in free CA in plasma due to the administration of an exogenous form or release of endogenous CA from the tissues.

Formation of 8-hydroxyguanine and 2,6-diamino-4-hydroxy-5-formamidopyrimidine in DNA by riboflavin mediated photosensitization

Calf thymus DNA was photoirradiated in the presence of riboflavin. Altered bases were detected and quantified by the GC/MS-SIM method after hydrolysis and derivatization of DNA. Seven types of modified purine bases were detected in control DNA. Among them, the yields of 8-OH-Gua and FapyGua increased significantly in DNA photo-irradiated with riboflavin, whereas the yields of xanthine, 8-OH-Ade, 2-OH-Ade, FapyAde and hypoxanthine were not affected. A dose dependent increase in the formation of 8-OH-Gua was observed with increasing riboflavin concentration for 30 min irradiation. On the other hand, FapyGua reached plateau at 10 micrograms/ml of riboflavin for 30 min irradiation. Our results indicate that guanine moiety in DNA is the most susceptible to riboflavin mediated photosensitization.

Repair kinetics of abasic sites in mammalian cells selectively monitored by the aldehyde reactive probe (ARP)

Human methylpurine N-glycosylase (MPG) activity was investigated by monitoring abasic (AP) sites resulting from removal of alkylated bases. The amount of AP sites in MMS-treated HeLa cells transiently increased at 3 h, then gradually decreased to 40% at 24 h. The presence of adenine, an inhibitor of AP endonucleases, in the repair incubation of MMS-treated cells induced moderate accumulation of AP sites, suggesting inhibition of the activities of MPG as well as AP endonucleases by adenine metabolites.