Insights into familial adult myoclonus epilepsy pathogenesis: How the same repeat expansion in six unrelated genes may lead to cortical excitability

Familial adult myoclonus epilepsy (FAME) results from the same pathogenic TTTTA/TTTCA pentanucleotide repeat expansion in six distinct genes encoding proteins with different subcellular localizations and very different functions, which poses the issue of what causes the neurobiological disturbances that lead to the clinical phenotype. Postmortem and electrophysiological studies have pointed to cortical hyperexcitability as well as dysfunction and neurodegeneration of both the cortex and cerebellum of FAME subjects. FAME expansions, contrary to the same expansion in DAB1 causing spinocerebellar ataxia type 37, seem to have no or limited impact on their recipient gene expression, which suggests a pathophysiological mechanism independent of the gene and its function. Current hypotheses include toxicity of the RNA molecules carrying UUUCA repeats, or toxicity of polypeptides encoded by the repeats, a mechanism known as repeat-associated non-AUG translation. The analysis of postmortem brains of FAME1 expansion (in SAMD12) carriers has revealed the presence of RNA foci that could be formed by the aggregation of RNA molecules with abnormal UUUCA repeats, but evidence is still lacking for other FAME subtypes. Even when the expansion is located in a gene ubiquitously expressed, expression of repeats remains undetectable in peripheral tissues (blood, skin). Therefore, the development of appropriate cellular models (induced pluripotent stem cell-derived neurons) or the study of affected tissues in patients is required to elucidate how FAME repeat expansions located in unrelated genes lead to disease.

[Unilateral diseases of the maxillary sinus]

Unilateral diseases of the maxillary sinus are among the most common rhinologic diagnoses. The diversity of these diseases can represent a challenge for the treating physician. The spectrum ranges from harmless maxillary sinus cysts that seldom require treatment, to highly aggressive malignant tumors. Special attention should be given to the management of inverted papilloma. These benign tumors are characterized by high recurrence rates and the potential for malignant transformation. The key to minimizing recurrence is precise surgical intervention. Other unilateral maxillary sinus diseases such as the antrochoanal polyp and the fungus ball (aspergilloma) are also discussed in depth.

A human somatic cell culture system for modelling gene silencing by transcriptional interference

Transcriptional interference and transcription through regulatory elements (transcriptional read-through) are implicated in gene silencing and the establishment of DNA methylation. Transcriptional read-through is needed to seed DNA methylation at imprinted genes in the germ line and can lead to aberrant gene silencing by DNA methylation in human disease. To enable the study of parameters and factors influencing transcriptional interference and transcriptional read-through at human promoters, we established a somatic cell culture system. At two promoters of imprinted genes (UBE3A and SNRPN) and two promoters shown to be silenced by aberrant transcriptional read-through in human disease (MSH2 and HBA2) we tested, if transcriptional read-through is sufficient for gene repression and the acquisition of DNA methylation. Induction of transcriptional read-through from the doxycycline-inducible CMV promoter resulted in consistent repression of all downstream promoters, independent of promoter type and orientation. Repression was dependent on ongoing transcription, since withdrawal of induction resulted in reactivation. DNA methylation was not acquired at any of the promoters. Overexpression of DNMT3A and DNMT3L, factors needed for DNA methylation establishment in oocytes, was still not sufficient for the induction of DNA methylation. This indicates that induction of DNA methylation has more complex requirements than transcriptional read-through and the presence of de novo DNA methyltransferases.

Unstable TTTTA/TTTCA expansions in MARCH6 are associated with Familial Adult Myoclonic Epilepsy type 3

Familial Adult Myoclonic Epilepsy (FAME) is a genetically heterogeneous disorder characterized by cortical tremor and seizures. Intronic TTTTA/TTTCA repeat expansions in SAMD12 (FAME1) are the main cause of FAME in Asia. Using genome sequencing and repeat-primed PCR, we identify another site of this repeat expansion, in MARCH6 (FAME3) in four European families. Analysis of single DNA molecules with nanopore sequencing and molecular combing show that expansions range from 3.3 to 14 kb on average. However, we observe considerable variability in expansion length and structure, supporting the existence of multiple expansion configurations in blood cells and fibroblasts of the same individual. Moreover, the largest expansions are associated with micro-rearrangements occurring near the expansion in 20% of cells. This study provides further evidence that FAME is caused by intronic TTTTA/TTTCA expansions in distinct genes and reveals that expansions exhibit an unexpectedly high somatic instability that can ultimately result in genomic rearrangements.

[Diagnosis and management of vascular malformations : Interdisciplinary teamwork in demand]

Vascular anomalies are very rare, but can occur in children and adults in almost every region of the body. Due to the complexity of this disease, the path to a definitive diagnosis is often difficult. It requires interdisciplinary teamwork with close exchange of information between the individual treatment partners to reach the correct diagnosis and then to start the best therapy. This article provides an overview of the main types of vascular malformations from a clinical, imaging, and histological point of view, following the current classification of the International Society for the Study of Vascular Anomalies (ISSVA).

[Recognition and prevention of problems in lacrimal duct surgery]

Surgical management of lacrimal duct obstruction beyond the canaliculi proves to be a promising endeavor in most cases. To realize the full potential of endonasal dacryocystorhinostomy, some aspects of diagnosis and differential indication setting should be considered in order to avoid errors and problems during patient selection, execution of the technical procedure, and communication with ophthalmologists. These issues are described according to the clinical management of patients; current literature is cited.

[Aerosinusitis. Part 2: Diagnosis, therapy and recommencement of flight duties]

Aerosinusitis more frequently affects the frontal sinus than the maxillary sinus and mostly occurs during descent. Sinonasal diseases and anatomic variations leading to obstruction of paranasal sinus ventilation favor the development of aerosinusitis. This Continuing Medical Education (CME) article is based on selective literature searches of the PubMed database (search terms: "aerosinusitis", "barosinusitis", "barotrauma" AND "sinus", "barotrauma" AND "sinusitis", "sinusitis" AND "flying" OR "aviator"). Additionally, currently available monographs and further articles that could be identified based on the publication reviews were also included. In part 2, diagnostic measures, drug therapy, balloon dilatation and endoscopic sinus surgery are presented, along with a discussion regarding when flight attendants and pilots are able to resume their work. Endoscopic surgery to expand the natural drainage pathways of the affected sinuses with minimal surgical trauma to the healthy mucous membranes is largely successful.

Loss of PTEN is associated with elevated EGFR and HER2 expression and worse prognosis in salivary gland cancer

Background:

Activity of the tumour-suppressor gene PTEN is reduced in different types of cancer and implicates non-responsiveness to targeted therapy. This study evaluates the gene and protein status of PTEN in salivary gland carcinomas.

Methods:

A total of 287 carcinomas of the major and minor salivary glands were investigated for phosphatase and tensin homologue located on chromosome 10 (PTEN) deletion and loss of PTEN expression using fluorescence in situ hybridisation (FISH) and immunohistochemistry (IHC), respectively. Results were correlated to clinicopathological parameters, long-term survival, epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) (IHC and FISH) status of the tumours.

Results:

Hemizygous deletions of PTEN were found in 35 out of 232 (15.1%) carcinomas, while homozygous deletions were observed in 17 out of 232 (7.3%) tumours. Phosphatase and tensin homologue located on chromosome 10 deletion was common in certain histological subtypes and especially homozygous deletion was associated with high-grade malignancy, lymph node metastases and unfavourable long-term prognosis (P<0.001). Loss of PTEN expression was present in 59 out of 273 (21.6%) carcinomas and was significantly correlated to genomic PTEN deletion, high-grade malignancy (P<0.001), increased tumour size (P=0.036), lymph node metastases (P=0.007) and worse disease-specific survival (P=0.002). Genomic PTEN deletion, in particular homogenous deletion (P<0.001) predominantly occurred in tumours with increased gene copy number of EGFR (60.0%) and/or amplification of HER2 (63.6%). Loss of PTEN expression was frequently found in tumours overexpressing EGFR (28.6%) and/or HER2 (52.6%).

Conclusion:

PTEN function is reduced in different types of salivary gland cancer indicating unfavourable prognosis. Its association with EGFR and HER2 signalling might affect targeted therapy.

[Perioperative pain and anxiety in endoscopic sinus surgery]

BACKGROUND

Aim of this study was to evaluate the perioperative level of pain and anxiety for endoscopic sinus surgery, and to compare 3 different types of nasal packing.

MATERIAL AND METHODS

Prospective, controlled, randomized study comparing different types of nasal packing in regard to perioperative anxiety and pain. Patients suffered from chronic rhinosinusitis with nasal polyps involving all paranasal sinuses. Patients daily evaluated by standardized questionnaires (FPI-R, KASA, STAI) and also visual analog scale for pain on 5 consecutive days before and after endoscopic sinus surgery of all paranasal sinuses. Nasal packings were removed on 2(nd) postoperative day.

RESULTS

A total of 73 patients (polyvinyl acetate packing N = 14, glove packing N = 37, glove packing with breathing tubes N = 22) completed the study. Female gender, bad preoperative mood and absence of pain were associated with increased preoperative state anxiety based on regression analysis. Also, preoperative gathering of additional information from relatives and friends was correlated with increased preoperative anxiety. Patients had significantly minor preoperative anxiety if they could expect use of nasal packings with breathing tubes.

CONCLUSION

Female patients, who gathered information about the operation from friends or relatives or patient in worse preoperative mood are at risk for increased state anxiety and should be identified prior to rhinosurgical procedures. Use of nasal packing with at least partially preserved nasal breathing is recommended in clinically anxious patients.

[S1 guideline on the "diagnosis and treatment of snoring in adults"]

Due to the frequency of this phenomenon and the often considerable distress caused to the affected person, competent advice, diagnosis and treatment of snoring in adults is of particular importance. The aim of this guideline is to promote high-quality medical care for patients affected by this problem. According to the three-level concept of the AWMF, it corresponds to an S1 guideline. Prior to any therapeutic intervention, relevant sleep medical history, clinical examination, as well as a mandatory objective diagnostic measure are performed. Snoring is only treated if the patient asks for it. In general, invasive methods should be viewed critically and the patient should be advised correspondingly. In the case of surgical therapy, minimally invasive techniques are preferred. Reducing body weight (in the case of overweight snorers), abstinence from alcohol, nicotine and sleep medication, as well as maintaining a healthy sleep-wake cycle can be recommended from a sleep-medicine perspective, although convincing clinical studies are not yet available. Since evidence for the effectiveness of muscle stimulation or various methods for toning and training of the muscles of the floor of mouth is not available, these methods are not recommended. Snoring can be successfully treated with the use of an intraoral device; however, careful patient selection is important. Avoiding a supine position during sleep can be helpful in some cases. Only limited data is available on the success rates of the surgical approaches and long term data is often lacking, and not all techniques have been sufficiently evaluated from a scientific point of view. Nasal surgery is only indicated if the patient suffers from nasal obstruction. Extensive data supports the effectiveness of laser-assisted resection of excessive soft palate tissue (laser-assisted uvuloplasty, LAUP). In principle, however, such resections can be performed using other techniques. Placebo-controlled studies were able to prove the effectiveness of radiofrequency surgery of the soft palate. A reduction in snoring could also be achieved in many cases by means of soft palate implants with minimal post-operative morbidity. The indication for tonsillectomy and uvulopalatopharyngoplasty should be made cautiously due to the comparatively high morbidity associated with these procedures.

[Laser skin resurfacing and fibrin sealing as successful treatment for facial angiofibromas in tuberous sclerosis]

Tuberous sclerosis complex (TSC) is an autosomal-dominant phacomatosis that manifests with visceral harmatomas, epilepsy, and mental retardation. Paranasal angiofibromas may cause bleeding and difficulties in nasal breathing and can stigmatise the individual. When treating TSC patients, the otolaryngologist must take patient compliance and the tendency to develop malignancies into account. We report on a 34-year-old woman who was treated successfully by a combination of CO(2) laser treatment and fibrin glue. The cosmetic results were excellent.

[Therapy of bony and fibrous contractures and buccal defects after noma using the temporalis muscle flap]

METHODS

A prospective pilot study was conducted on 12 patients to establish whether, under the difficult conditions prevailing in a developing country, the temporalis muscle flap is suitable as a safe and single-stage procedure for the repair of buccal defects combined with fibrous or osseous contractures of the temporomandibular joint.

RESULTS

The surgical procedures were performed from 1998 to 2000 in the Hôpital National du Niamey (Republic of Niger). Primary healing was achieved with all grafts. Local clinical and radiological follow-up (in Niger) was performed on seven patients after 12 and 24 months. Mouth opening of at least 1.5 cm was achieved in all cases, although there was virtually no use of physiotherapy to prevent scar contracture.

DISCUSSION

By contrast with expensive and surgically more complex reconstructions, our use of this procedure shows that even where medical conditions are less than ideal, a satisfactory functional and cosmetic result can be achieved in the long-term.

Mirror system for photodocumentation in plastic and aesthetic surgery

Photodocumentation of the face before aesthetic or plastic surgery is of fundamental importance for at least three reasons: it is an aid to surgical planning, it can be used for illustrative purposes in discussions with the patient, and it satisfies medico-legal requirements for documentation. To achieve efficient and economic documentation of preoperative and postoperative status in aesthetic and reconstructive plastic procedures, the mirror system described here permits the required planes to be documented in a single photograph. The simple and inexpensive technical design allows six planes to be documented in constant and, therefore, comparable quality. Because the patient's data are also documented with the photographic record, the potential for mistaken patient identity is eliminated. No technical training is needed to operate the device and it can, therefore, be readily used by ancillary medical personnel. In a typical nasal surgery department performing about 150 rhinoplasty procedures per annum, the mirror system offers cost and time savings generated as a result of reducing the documentation burden by 750 photographs.

Prognostic value of nuclear survivin expression in oesophageal squamous cell carcinoma

Survivin, a new member of the family of apoptosis inhibitors, is expressed almost exclusively in proliferating cells, above all in cancers. Subcellular localisation and prognostic implications of the survivin protein have not yet been determined in oesophageal squamous cell carcinoma. The survival of 84 patients with oesophageal squamous cell carcinomas was correlated with the extent of immunohistochemical survivin expression in tumour cell nuclei. Tumours were scored positive when >5% cells stained positive. Patients were followed up for at least 5 years or until death. In normal oesophageal squamous cell epithelium, some cytoplasmic survivin expression was detected in the basal cells, whereas proliferating cells showed nuclear staining of survivin. Nuclear expression of survivin was also detected in 67 cancers (80%). The mean survival for patients of this group (28 months, range 20-36) was significantly less than that for patients without survivin expression in the tumour cell nuclei (108 months, range 62-154, P=0.003). Using univariate analysis, nuclear survivin expression (P=0.003), tumour depth (P=0.001), lymph node metastasis (P=0.003) and stage (P<0.001) were the best predictors of survival. In contrast, cytoplasmic survivin staining was noted in 53 (63%) tumours and had no prognostic relevance. In conclusion, the analysis of nuclear survivin expression identifies subgroups in oesophageal squamous cell cancer with favourable (survivin(-)) or with poor prognosis (survivin(+)). We suggest that the determination of nuclear survivin expression could be used to individualise therapeutic strategies in oesophageal squamous cell cancer in the future.

[Interdisciplinary endoscopic outpatient management of connatal dacryocystoceles]

Dacryocystocele may represent a rare type of connatal stenosis of the lacrimal duct. If conservative measures fail and in case of secondary inflammation, probing or regular surgery is usually recommended. We report on 15 neonates suffering from 18 connatal dacryocystoceles which were presented to the clinic of ophthalmology at the 16th (6 - 44) day of life. There was a definite female preponderance (65 %). Conservative treatment (external massage, at times i. v. antibiotic therapy) had proven to be ineffective. The neonates were subjected to outpatient nasal endoscopy and the ballooning cyst of the inferior nasal meatus was managed by endoscopic marsupialization in 14 cases applying local anesthesia. Two nasal cysts had to be operated on in general anesthesia due to obstructing local anatomy which obviated endoscopical microsurgery. Three additional dacryocystoceles have been detected incidentally in 2 neonates being subjected to surgery in general anesthesia for choanal atresia and lacrimal probing respectively. The corresponding dacryocystoceles were managed by concomitant endonasal microsurgery. We advocate interdisciplinary (ophthalmological and rhinological) outpatient examination in all neonates with suspected dacryocystoceles. Diagnosis is based on palpation, probing and nasal endoscopy applying local anesthesia together with mucosal decongestion. Microsurgical marsupialization immediately follows and will lead to persisting relief of symptoms.

Evaluation of powered instrumentation in out-patient revisional sinus surgery

A feasibility study was carried out to prove the benefits of powered instrumentation, i.e. microdebrider in revisional surgery under local anaesthesia of chronic sinusitis in out-patients. Acceptance by the patients was investigated by questionnaire. Out-patient surgery is well tolerated by the majority (79.2%) of patients. Ninety-four percent would undergo the treatment again if necessary. An operation under general anaesthesia could be avoided in the cases we submitted to investigation. The cost-effectiveness of the method is thus an important consideration, despite calculating high prime costs and rather expensive, expendable instrumentation. Special consideration is attributed to a new feature added to the debrider device. To improve out-patient care, we developed an integrated electrocoagulation unit which supplements the microdebrider. It proved to be effective and easy to use. Bleeding was reduced to a minimum. Hence, nasal packing could be avoided in all out-patient cases. The possibility of causing severe complications using the microdebrider-technique is not eliminated as was shown in the anatomical specimens. Based on our experience, reduction of strong bony structures is subject to limitations at present. We therefore recommend the use of microdebriders for soft tissue manipulations, especially in revisional surgery. The microdebrider proved to be a significant advantage in out-patient surgery for recurrent sinusitis.

Histochemical detection of lymphatic drainage pathways in the middle nasal meatus

Following extensive middle meatal antrostomy, even without manipulation inside the maxillary sinus, a reactive edema of the maxillary sinus mucosa may be subsequently detected. A presumptive correlation has been established between this particular mucosal reaction and insufficient maxillary lymphatic drainage. Histochemical examination of the lymphatic drainage pathways was carried out on surgical specimens. During the performance of surgical maxillary fenestrations, 80 surgical specimens of the middle nasal meatus were obtained including adjacent parts of the medial maxillary wall. The specimens were subjected to visualization of lymphatic vessels based on the histochemical detection of 5'-nucleotidase according to Werner (1993). Both the nasal and the maxillary sinus mucosa showed a distinct superficial and deep longitudinal lymphatic capillary network (15-200 mu phi) with an orientation towards the natural maxillary sinus ostium. The density of the network increased from cranial to caudal, from dorsal to ventral and reached maximum density at the natural maxillary ostium. Lymphatic vessels of the maxillary sinus mucosa were thin but numerous in comparison to nasal vessels. The maxillary lymphatic capillary network showed direct connections to the nasal vessels, not only along the mucosal folds of the primary maxillary sinus ostium, but also in most cases (57%) transmurally through the natural bony gaps of the uncinate process. Grünwald's theory (1910) which states that lymphatic drainage of the maxillary sinus is established exclusively along the mucosal pane through the natural ostium was disproved. Maxillary mucosal congestion subsequent to extensive middle meatal antrostomy may be explained by ablation of the intramural and transmural lymphatic drainage pathways.

Endonasal frontal sinusotomy in surgical management of chronic sinusitis: a critical evaluation

Frontal sinusotomy was performed on 110 patients undergoing routine endoscopic endonasal ethmoidectomy and the minimum diameter of the frontal sinus neo-ostium was determined intraoperatively. A total of 82 patients could be subjected to follow-up and redetermination of the neo-ostium diameter 13 months later. A postoperative CT was scheduled in 62 cases. The average minimum diameter of the frontal sinus neo-ostium, measured intraoperatively, was 5.6 mm (0-11 mm). After completion of wound healing, 81% of the frontal sinuses could be explored by probing or even inspected by rigid endoscopy. The average minimum diameter of the neo-ostia determined postoperatively was 3.5 mm (0-11 mm). Patients exhibiting aspirin sensitivity or diffuse nasal polyposis showed a more pronounced scarred constriction of the frontal sinus access compared to other cases. Neo-ostia exceeding 5 mm intraoperatively were preserved with a considerably higher percentage than those with diameters of less than 5 mm. Radiologically, the fenestrated frontal sinuses frequently showed continued or even increasing mucosal congestion. No conclusive relationship was found to exist between such post-operative clouding and frontal sinus accessibility (endoscopy and/or probing) or patient complaints. The investigations confirm the safety and reliability of frontal sinusotomy in surgical management of chronic paranasal sinusitis. The mucosa of the frontal sinus often reacts to surgery in the form of persistent or even newly developing mucosal swelling to which a specific pathophysiological significance cannot always be attributed.

[How traumatising is mechanical mucous membrane care after interventions on paranasal sinuses? A histological immunohistochemical study]

OBJECTIVE

Endonasal sinus surgery lead to more or less circumscribed mucosa defects exposing the underlying bone. Healing of these wounds is accompanied by crust formation, which may be subjected to mechanical debridement. It is not known whether this wound care impaires or facilitates wound healing.

METHODS

Following sinus surgery, 72 crusts were removed from the operative site after having taken endoscopic photographs choosing different postoperative intervals. Mucosal biopsies were taken from beneath the crusts. All specimen were submitted to routine histological serial sections as well as immunohistochemical staining of epithelium.

RESULTS

Local debridement of crusts avulsed parts of epithelium in 23% of cases during the first postoperative week. There was no histological evidence of avulsed epithelium with crusts removed the second week. This figure later increased to 16%. Possible trauma to regenerating mucosa cannot be predicted solely by the appearance of crusts.

CONCLUSION

In principle, large crusts may disturb ventilation and drainage, causing secondary mucositis. Local care is mandatory in these cases. According to our examinations, mechanical debridement of wounds must respect the time-dependent irritability of the healing wound. There is little risk of impairing epithelization during the second week after surgery and the chance of sustaining the healing process is best.

[Drying with hexamethyldisilizane--a time-saving alternative to the "critical point" method]

The capability of Hexamethyldisilizane (HMDS) as a solute for the last step in the dehydration of biological material for scanning electron microscopy was tested in the renal vessels of the rat. The HMDS-drying-method proved to be an economical alternative to the critical-point method.