A Rhinofacial Conidiobolus coronatus Fungal Infection Presenting as an Intranasal Tumour.

Conidiobolomycosis is a rare fungal infection that affects adults in tropical regions. We report a 42-year-old male patient who was referred to the Sulaiman Al Habib Hospital, Dubai, United Arab Emirates (UAE), in 2013 with excessive nasal bleeding and a suspected nasal tumour. He reported having briefly visited central India nine months previously. Computed tomography and magnetic resonance imaging showed a highly vascularised mass in the nasal cavity. However, after surgical excision, initial treatment with amphotericin B deoxycholate was unsuccessful and the disease progressed, leading to external and internal nasal deformation and necessitating further excision and facial reconstruction. Histopathological analysis of the second biopsy revealed Splendore-Hoeppli changes consistent with a fungal infection. Microbiological findings subsequently confirmed Conidiobolus coronatus. Subsequently, the patient was successfully treated with a combination of itraconazole and fluconazole. To the best of the authors' knowledge, this is the first report of a case of rhinofacial conidiobolomycosis from the UAE.

Comparison of Postoperative Pain in Children with Two Intracapsular Tonsillotomy Techniques and a Standard Tonsillectomy: Microdebrider and radiofrequency tonsillotomies versus standard tonsillectomies.

OBJECTIVES: The aim of this study was to compare the duration and severity of postoperative pain for two different tonsillotomy techniques (radiofrequency [RF] and microdebrider [MD]) with the standard tonsillectomy. METHODS: This non-randomised retrospective study, carried out from February 2011 to September 2012, investigated 128 children in two independent centres: Heim Pál Children's Hospital in Budapest, Hungary, and Muscat Private Hospital in Muscat, Oman. Those undergoing conventional tonsillectomies acted as the control group. One centre tested the MD technique (n = 28) while the other centre tested the RF technique (n = 31). RESULTS: The pain-free period after the tonsillotomies was similar between the two techniques and ranged up to three days. Other indicators of pain resolution, like the use of a single analgesic, reduced night-time waking and the time taken to resume a normal diet, were also similar for the two groups. However, patients benefited significantly from having a tonsillotomy rather than a tonsillectomy. CONCLUSION: The partial resectioning of tonsillar tissue using the MD and RF techniques showed promising outcomes for a better postoperative quality of life when compared to a traditional tonsillectomy. In this study, the results of both the MD and RF tonsillotomy methods were almost identical in terms of the duration of postoperative pain and recovery time.

A new mutation in the human pres gene and its effect on prestin function.

The electromotility of cochlear outer hair cells (OHCs) is a major factor in cochlear amplification that enhances the sensitivity of hearing in humans. Prestin is associated with presumed conformational changes in an integral membrane protein. Prestin knockout (-/-) mice display loss of OHC electromotility and a 40- to 60-dB reduction in cochlear sensitivity in vivo. In the present study we described the results of a direct sequencing mutation in the pres gene that was found in genetic screening performed in 47 patients characterized by non-syndromic, mild-to-moderate hearing impairment (30-70 dB) and in 50 control subjects from Hungary, after exclusion of GJB (GJB2, GJB6) mutations in the background. Only one patient and his normal-hearing father showed a heterozygous missense mutation (R150Q/WT) in the 6th coding exon of the pres gene. None of the 50 control subjects with normal hearing carried this mutation. Electrophysiological studies on the R150Q (homozygous and heterozygous) prestin mutant transiently transfected into reporting cells demonstrated nonlinear capacitance functions (NLC) as a signature of OHC electromotility. The capacitance function in human kidney cell line TSA 201 was similar for wild-type prestin and the mutant. However, for the mutant the voltage where the maximal charge displacement occurred (V1/2) significantly shifted in the hyperpolarizing direction ( approximately 15 mV). This is the first genetic and electrophysiological analysis of a human mutation in a coding exon of the pres gene by 47 patients with non-syndromic, sensorineural, mild-to-moderate hearing impairment; although the pathogenic role of the R150Q mutation is not unambiguous.

The C-terminus of prestin influences nonlinear capacitance and plasma membrane targeting.

Prestin is a unique molecular-motor protein expressed in the lateral plasma membrane of outer hair cells (OHC) in the organ of Corti of the mammalian cochlea. It is thought that prestin undergoes conformational changes driven by the cell's membrane potential. The resulting alterations in OHC-length are assumed to constitute the cochlear amplifier. Prestin is a member of the anion solute carrier family 26 (SCL26A), but it is different from other family members in its unique function of voltage-driven motility. Because the C-terminus is the least conserved region in the family, we investigated its influence with a series of deletion, point and chimeric mutants. The function and cellular expression of mutants were examined in a heterologous expression system by measurement of nonlinear capacitance (NLC) and immunofluorescence. Each mutant produced a unique mixture of patterns of cell morphologies, which were classified as to the location of prestin within the cell. The data from deletion mutants (Del516, Del525, Del630, Del590, Del709, Del719) revealed that nearly the full length (>708 amino acids) of the protein was required for normal prestin expression and function. Since most deletion mutations eliminated plasma membrane targeting, chimeric proteins were constructed by fusing prestin, at amino acid 515 or 644, with the homologous portion of the C-terminus from the two most closely related SLC26A members, pendrin and putative anion exchanger 1. These chimeric proteins were again improperly (but differently) targeted than simple truncation mutants, and all lacked functional phenotype. When two of the potential basolateral membrane-targeting motifs were mutated (Y520A/Y526A), incomplete plasma membrane expression was seen. We also show that some double point mutations (V499G/Y501H) fully express in the plasma membrane but lack NLC. These non-charged amino acids may have unrevealed important roles in prestin's function. Together, these data suggest that certain specific sequences and individual amino acids in the C-terminus are necessary for correct cellular distribution and function.

Effects of cyclic nucleotides on the function of prestin.

Outer hair cells (OHCs) in the mammalian organ of Corti display electromotility, which is thought to provide the local active mechanical amplification of the cochlear response. Prestin is the key molecule responsible for OHC electromotility. Several compounds, including cGMP, have been shown to influence OHC electromotility. There are two potential cAMP/cGMP-dependent protein kinase phosphorylation sites on prestin. Whether these sites are involved in cGMP-dependent reactions is as yet unknown. In this study, prestin cDNA was transiently transfected into TSA 201 cells. Cells that expressed prestin were selected to measure non-linear capacitance (NLC), a signature of outer hair cell motility. We applied cGMP and cAMP analogues and a protein kinase G (PKG) antagonist to the cells. Furthermore, nine mutations at putative phosphorylation sites of prestin were produced. The neutral amino acid alanine replaced serine/threonine at phosphorylation sites to change the conserved phosphorylation motif in order to mimic the dephosphorylated state of prestin, whereas replacement with the negatively charged aspartic acid mimicked the phosphorylated state. The properties of such modified prestin-expressing cells were examined, through measurement of NLC and with confocal microscopy. Our data demonstrate that cGMP is significantly more influential than cAMP in modifying the non-linear, voltage-dependent charge displacement in prestin-transfected cells. The electrical properties of the single and double mutations further indicate a possible interaction between the two PKG target sites. One of these sites may influence the membrane targeting process of prestin. Finally, a new topology map of prestin is proposed.