Subwavelength resolution in a two-dimensional photonic-crystal-based superlens

We experimentally and theoretically demonstrate single-beam negative refraction and superlensing in the valence band of a two-dimensional photonic crystal operating in the microwave regime. By measuring the refracted electromagnetic waves from a slab shaped photonic crystal, we find a refractive index of -1.94 that is very close to the theoretical value of -2.06. A scanning transmission measurement technique is used to measure the spatial power distribution of the focused electromagnetic waves that radiate from a point source. The full width at half maximum of the focused beam is measured to be 0.21 lambda, which is in good agreement with the finite difference time domain method simulations. We also report a subwavelength resolution for the image of two incoherent point sources, which are separated by a distance of lambda/3.

MRI cisternography with gadolinium-containing contrast medium: its role, advantages and limitations in the investigation of rhinorrhoea

Our purpose was to evaluate the utility of intrathecal gadopentetate dimeglumine -enhanced magnetic resonance cisternography (GdMRC). We injected 0.5 ml contrast medium into the subarachnoid space via lumbar puncture in 20 patients with suspected cerebrospinal fluid (CSF) rhinorrhoea. MRC showed CSF leakage in 14 patients with rhinorrhoea at the time of the examination, into the ethmoid air cells in nine, the sphenoid sinus in three and the frontal sinus in two cases. In 12 of these the site leakage was confirmed during surgical repair of the fistula. No leakage was observed in four patients with intermittent rhinorrhoea, not present at the time of the examination. GdMRC showed leakage in two patients with negative CT cisternography. GdMRC may prove better than CT cisternography, especially with slow CSF flow. We also showed low-dose GdMRC to be a feasible and relative safe way of confirming the presence of and localising active CSF leaks prior to surgical repair.

An unusual complication of stapes surgery: profuse bleeding from the anteriorly located sigmoid sinus

Major bleeding during stapes surgery is a rare condition. The anterior course of the sigmoid sinus is comparatively common in contracted mastoid bones, but rare in good pneumatized temporal bones. We report a case of an unusual anterior course of the vertical segment of the sigmoid sinus, which led to profuse bleeding during a stapedotomy operation. The 34-year-old female patient presented with conductive-type hearing loss in the right ear. During the operation, the unintentional sliding movement of a blunt curette caused injury to the anteriorly positioned sigmoid sinus, which was separated from the posterior wall of the external auditory canal by an extremely thin shell of bone. Profuse bleeding from the sigmoid sinus was controlled by pushing the middle part of the oxidised regenerated cellulose inside the lumen, without compromising the sinus flow. After bleeding was restrained, the stapedotomy operation was completed successfully. During the 1-year follow-up, there was neither an air-bone gap nor a sensorineural hearing loss in pure tone audiogram.

Informal consultations in infectious diseases and clinical microbiology practice

Informed consultation between physicians is an important part of medical practice. The aim of the study was to evaluate the nature and frequency of such consultations in infectious diseases and clinical microbiology practice. This study was done in five university hospitals. Twenty-one infectious diseases and clinical microbiology specialists participated in informal ('curbside') consultations. In a written questionnaire, physicians were asked to report the number and nature of the informal consultations (ICs) they were asked to provide. A total three hundred and sixty-two such consultations were carried out during a three-month period. The ICs occurred most frequently in the hospital (82.3%). Most of the ICs from outside the hospital were by telephone. Most of the ICs (54.4%) were requested by fellows of specialists. 78.7% of the ICs were requested during working hours. 58.8% of consultations took less than 5 min, 18.8% took 6-10 min, 15.2% took 11-20 min, and 7.2% took over 20 min. The four most common reasons for obtaining ICs were to: help to select an appropriate treatment plan (41.4%), help to select an appropriate prophylaxis (19.3%), interpret laboratory data (10.2%), and provide information about antibiotics (10.2%). 30.1% of ICs resulted in subsequent formal consultation and only four patients (1.1%) were transferred to the consultants' clinics. Informal consultations are a frequent occurrence in the practice of infectious diseases and clinical microbiology (ID&CM). Physicians use this sort of consultation to select an appropriate treatment plan and obtain medical information. This study confirms the importance of the ID&CM specialists as a resource for medical personnel.

Imaging in tuberculosis of the skull and skull-base: case report

We report a 19-year-old girl, who presented with headache and tonic/clonic seizures. Imaging revealed a lytic parietal skull lesion with an adjacent epidural mass, masses in the right parietal lobe and a posterior skull-base mass. The diagnosis of tuberculosis was made after resection of the extradural mass and later verified with culture of Mycobacterium tuberculosis. The parenchymal and skull-base lesions resolved following antituberculous treatment. We present CT, scintigraphic, angiographic and MRI findings.

A new MRI method for the quantitative evaluation of extraocular muscle size in thyroid ophthalmopathy

In cross section, extraocular muscles are more or less elliptical, with short and long diameters. We studied the ratio (R) of short to long diameter and investigated its use in quantitative assessment of the extraocular muscles in patients with Graves's disease. We measured the diameters on T1-weighted axial and coronal MRI and computed R for each extraocular muscle in 80 patients without and 40 with Graves's disease. We compared the measurements and R of the right and left orbits, and of men and women. The short diameter of all extraocular muscles apart from the superior oblique showed significant differences between men and women, and that of the inferior rectus varied significantly with age. R, however, was unrelated to sex or age. All patients with Graves's disease and an increased short diameter also had an increased R, but 6% of the muscles showed an increase in R, even though their short diameter was within the normal range.

Case report: Spinal cord herniation into a mediastinal neurenteric cyst: CT and MRI findings

Split notochord syndrome is a spectrum of congenital spinal malformations that develops due to an adhesion between endoderm and ectoderm causing the "splitting" of notochord. Neurenteric cyst is one of the components of split notochord syndrome. We report CT and MRI findings of an unusual case with thoracal spinal cord herniation into a mediastinal neurenteric cyst.

Evaluation of factors concerning the patency of the internal jugular vein after functional neck dissection

The aim of this study was to evaluate the effects of several factors on the patency of the internal jugular vein (IJV) after functional neck dissection (FND). A prospective clinical study was undertaken in 21 patients (36 neck dissections) before and after FND at the 1st and 3rd postoperative months by using duplex Doppler ultrasonography. The patients who had radiation therapy (RT) were evaluated again in the 6th postoperative month in order to assess possible late effects of radiation therapy. In our patients the patency rate was 100%, and no thrombosis was found. But the area at rest and during Valsalva's maneuver was reduced, and this difference was found to be statistically significant. It was concluded that the patency of the IJV remains normal after FND. Radiation therapy, infection or fistula formation have no detrimental effects on patency. In addition, the number of ligated branches do not seem to be related to the patency rate.

Case report: bilateral vocal cord paralysis caused by cervical spinal osteophytes

Thyroid and cervical surgery, tracheal intubation, trauma and neurodegenerative and neuromuscular diseases may cause bilateral vocal cord paralysis. There are only a few reported cases of bilateral cord paralysis associated with cervical hyperostosis in the English literature. We report the MR and CT findings of a case of bilateral vocal cord paralysis caused by cervical spinal osteophytes compressing the recurrent laryngeal nerves.

Cranial MR findings in chronic toluene abuse by inhalation

BACKGROUND AND PURPOSE

Chronic abuse of toluene by inhalation causes variable white matter changes and thalamic hypointensity on T2-weighted MR images. The purpose of our study was to assess cranial MR findings in a large series of patients who chronically abuse toluene-containing solvents to investigate the factors causing the qualitative variability of white matter changes and thalamic hypointensity.

METHODS

We studied the neurologic signs, symptoms, and cranial MR findings in 41 patients who chronically abused thinner, a toluene-containing solvent. We classified white matter changes as diffuse or restricted. We tested the associations of the development of white matter lesions and thalamic hypointensity with patient age at onset of abuse and duration of abuse.

RESULTS

MR images revealed white matter lesions in 46% of the patients, atrophic dilatation of ventricles and sulci in 27%, and thalamic hypointensity in 20%. White matter changes were restricted in 53% and diffuse in 47%. The development of white matter changes and thalamic hypointensity were significantly associated with duration of abuse longer than 4 years (P <.05 and P <.01, respectively).

CONCLUSION

White matter changes seem to start in the deep periventricular white matter, and they spread into peripheral white matter, causing the loss of gray matter-white matter differentiation with continued toluene abuse. The deposition of iron due to demyelination and axonal loss is the most probable mechanism for the thalamic hypointensity found in solvent abusers.

Different clinical features of amitraz poisoning in children

OBJECTIVE

To evaluate clinical experience of amitraz poisoning in children.

METHODS

In this study, the clinical and laboratory features of amitraz poisoning in 14 children are presented and compared with previous studies.

RESULTS

This study revealed that clinical manifestations of poisoning by oral and dermal routes appeared within 30-150 min, and that central nervous system (CNS) depression, which is the most important sign, improved within 6-24 hours and other signs within 24-72 hours. Unlike the findings in other studies, three severe cases in our study had reversible mydriasis and one of them required resuscitation because of cardiopulmonary arrest occurring as a result of serious respiratory depression. In addition, hepatic function test levels had increased in these three cases, and aspiration pneumonitis existed because of emesis in two of them.

CONCLUSION

There is little information in the literature about dermal poisoning. The signs and symptoms of dermal poisoning were relatively mild compared with oral poisoning, and there were no topical signs. The classical signs of alpha2-adrenergic stimulation such as marked sinusal bradycardia and mydriasis as reported in many poisoning cases of animals have not been reported before our three severe cases among children.

Predictors of outcome in patients with tuberculous meningitis

OBJECTIVE

To assess predictors of mortality and neurological sequelae in patients with tuberculous meningitis (TBM).

METHODS

Patients with TBM treated at 12 university hospitals in Turkey between 1985 and 1997 were evaluated using a standardised protocol applied retrospectively. Variables associated with hospital mortality as well as with the presence of neurological sequelae at 6 months were determined using logistic regression models.

RESULTS

Four hundred and thirty-four patients between the ages of 13 and 83 years (mean 33 years) were evaluated. Sixty-eight per cent of these patients presented with Medical Research Council Stage II or III. One hundred and one patients (23.3%) died and 67 (27%) of evaluable survivors had neurological sequelae. In multi-variable analysis, convulsion (OR 3.3, 95%CI 1.2-9.0, P = 0.02), comatose mental status (OR 6.0, 95%CI 3.6-10.2, P = 0.01), and delayed or interrupted treatment (OR 5.1, 95%CI 2.4-11.2, P = 0.01) were shown to be predictors for mortality. The presence of extra-meningeal tuberculosis (OR 2.1, 95%CI 1.1-4.2, P = 0.035), cranial nerve palsy (OR 2.6, 95%CI 1.4-4.2, P = 0.01), hemiparesia/focal weakness (OR 9.3, 95%CI 3.8-22.6, P = 0.01), hemiplegia/multiple neurological deficit (OR 7.1, 95%CI 2.14-23.38, P = 0.01) and drowsiness (OR 4.2, 95%CI 2.04-8.82, P = 0.01) were independent predictors of neurological sequelae at 6 months following hospital discharge.

CONCLUSION

The results of this study emphasise the importance of prompt and uninterrupted anti-tuberculosis therapy for tuberculous meningitis. The presence of seizures or coma on admission to hospital are important predictors for mortality, while the presence of focal neurological signs is a predictor for persistent neurological sequelae in survivors.

Thoracocervical dorsal dermal sinus associated with multiple vertebral body anomalies

Congenital dermal sinus is a type of closed spinal dysraphism. Cervical and thoracic regions are the rare sites for dorsal dermal sinuses. Dermal sinuses are frequently associated with dermoid or epidermoid tumor and osseous abnormalities such as bifid spinous process. The association of dorsal dermal sinuses with vertebral body anomalies is very rare. We present MR imaging features of a case of thoracocervical dorsal dermal sinus associated with multiple vertebral body anomalies.

A case of osteopetrosis with pelvic ectopic spleen: an unusual association

A three-month-old girl was admitted to the hospital with a history of pallor. On physical examination, the liver was enlarged and a solid mass was palpated in the left abdomen. Laboratory evaluation revealed anemia and thrombocytopenia. Bone marrow was hypocellular with reduced number of megakaryocytes. Radiographic findings and scintigraphic study of the long bones were consistant with osteopetrosis. In the imaging studies, including ultrasonography, computerized tomography, magnetic resonance imaging and scintigraphic study, an ectopic spleen expanded into the bony pelvis was observed. We report here unique case of infantile osteopetrosis associated with pelvic ectopic spleen.

Endocarditis caused by Stenotrophomonas maltophilia

Stenotrophomonas maltophilia is frequently isolated from hospital environments. In recent years, it has been reported that this bacterium is causing hospital infections at increasing rates and is gaining importance because of its multiple resistance. Although it has been related to several infections, endocarditis caused by S. maltophilia is rarely encountered. In this case study, endocarditis in a 40-y-old man with a history of aortic valve replacement is presented. Blood cultures revealed S. maltophilia to be the aetiological agent, which showed multiresistance to various antibiotics. Ticarcillin-clavulanate and trimethoprim-sulfamethoxazole were used in the treatment.

Effect of gamma Irradiation on Latex Film Dissolution

Latex films have been prepared by annealing pyrene (Py)-labeled poly(methyl methacrylate)-polyisobutylene particles at the glass transition temperature (100 degrees C). These films were then irradiated by gamma rays from (60)Co in a gamma cell at room temperature at various dose rates (rad/h). Before dissolution the films were annealed at 200 degrees C for a 30 min time interval to complete the film formation process. Steady-state fluorescence techniques were used to monitor the dissolution of irradiated latex films. Dissolution of films in a chloroform-heptane (80%-20%) mixture was monitored in real time by the Py fluorescence intensity change. Relaxation constants, k(0), and dissolution coefficients, D(d), of polymer chains were measured. Two different regimes of D(d) values were observed during dissolution, which are related to two different molecular weight distributions caused by scission and branching of polymer chains when they were irradiated and annealed. Copyright 2001 Academic Press.

Jacobson's nerve schwannoma presenting as middle ear mass

Schwannoma is one of the common benign middle ear space tumors. Middle ear space schwannomas may originate from the nerves of the tympanic cavity or by extensions from outside the middle ear space. In the English-language literature, the facial nerve and chorda tympani nerve, but not yet the tympanic branch of glossopharyngeal nerve (Jacobson's nerve), have been reported as the origins of intrinsic middle ear space schwannomas. We present the clinical and radiologic features of a middle-space schwannoma originating from Jacobson's nerve, and suggest that such a tumor be included in the differential diagnosis of middle ear tumors.

An atretic parietal cephalocele associated with multiple intracranial and eye anomalies

We present the cranial MRI findings in a 4-month-old girl with an atretic parietal cephalocele associated with multiple cerebral and ocular anomalies including lobar holoprosencephaly, a Dandy-Walker malformation, agenesis of the corpus callosum, grey-matter heterotopia, extra-axial cysts in various locations, bilateral microphthalmia and a retroocular cyst.

Persistent neonatal hypoglycemia: an unusual finding of congenital hypothyroidism

We report a newborn infant who has congenital hypothyroidism associated with profound and persistent neonatal hypoglycemia. Persistent and marked hypoglycemia has not been previously reported in congenital hypothyroidism to our knowledge. The cause of this condition may be reduced glyconeogenesis or insulin clearance.

Bilateral proptosis caused by orbital myositis. A case report

Proptosis, unilateral or bilateral, is a frequent indication for medical evaluation and orbital computed tomography. The most common cause of proptosis in adults and children is inflammatory disorders. Orbital myositis is a subgroup of the orbital pseudotumor syndrome in which one or more of the extraocular muscles are primarily infiltrated by an inflammatory process. Computed tomography and ultrasonography showed enlargement of one or more extraocular muscles in orbital myositis. In our case, we observed clinically and by orbital computed tomography, evidence of isolated bilateral extraocular muscle swelling after upper respiratory tract infection. Proptosis and other findings were spontaneously and completely resolved after twenty days. Because proptosis caused by orbital myositis is extremely rate in children and there is limited information in the literature, this case was reported.

Amitraz poisoning in children: clinical and laboratory findings of eight cases

Amitraz poisoning is a rare disorder characterised by central nervous system and respiratory depression, bradycardia, hypotension, hypothermia, hyperglycemia, vomiting, convulsion and glycosuria. In this study, eight pediatric patients with amitraz poisoning were presented. This study revealed that clinical manifestations of poisoning by oral and dermal route emerged within 30-120 min and that central nervous system depression which is the most important sign resolved with 8-18 h and others 36-48 h. All cases were discharged as recovered after 48 h. To our knowledge only six cases have been reported in the literature. Because of the limited information in the literature, the cases were reported.

Widespread detection of PER-1-type extended-spectrum beta-lactamases among nosocomial Acinetobacter and Pseudomonas aeruginosa isolates in Turkey: a nationwide multicenter study

We studied the prevalence and molecular epidemiology of PER-1-type beta-lactamases among Acinetobacter, Klebsiella, and Pseudomonas aeruginosa strains isolated over a 3-month period in eight university hospitals from distinct regions of Turkey. A total of 72, 92, and 367 Acinetobacter, Klebsiella, and P. aeruginosa isolates were studied, respectively. The presence of blaPER was determined by the colony hybridization method and later confirmed by isoelectric focusing. We detected PER-1-type beta-lactamases in 46% (33/72) of Acinetobacter strains and in 11% (40/367) of P. aeruginosa strains but not in Klebsiella strains. PER-1-type enzyme producers were highly resistant to ceftazidime and gentamicin, intermediately resistant to amikacin, and susceptible or moderately susceptible to imipenem and meropenem. Among PER-1-type-beta-lactamase-positive isolates, five Acinetobacter isolates and six P. aeruginosa isolates from different hospitals were selected for ribosomal DNA fingerprinting with EcoRI and SalI. The EcoRI-digested DNAs were later hybridized with a digoxigenin-labelled PER-1 probe. The ribotypes and the lengths of blaPER-carrying fragments were identical in four Acinetobacter strains. A single isolate (Ac3) harbored a PER gene on a different fragment (approximately 4.2 kbp) than the others (approximately 3.4 kbp) and showed a clearly distinguishable ribotype. Ribotypes of P. aeruginosa strains obtained with EcoRI showed three patterns. Similarly, in Pseudomonas strains two different EcoRI fragments harbored blaPER (approximately 4.2 kbp in five isolates and 3.4 kbp in one isolate). PER-1-type beta-lactamases appear to be restricted to Turkey. However, their clonal diversity and high prevalence indicate a high spreading potential.

Pulmonary involvement in adult Gaucher's disease: high resolution CT appearance

High resolution CT findings of pulmonary involvement are described in a patient with adult type Gaucher's disease. Although the reticular pattern on the chest radiograph was typical, appearance of pulmonary involvement on high resolution CT has not been demonstrated in the literature. High resolution CT demonstrated interlobular septal and intralobular interstitial thickening, irregular interfaces at the pleural surfaces and ground-glass appearance, corresponding to both the alveolar and the interstitial components of the pulmonary involvement.

The role of hepatitis E virus in acute sporadic non-A, non-B hepatitis

Hepatitis E virus (HEV) is the cause of enterically transmitted non-A, non-B (NANB) hepatitis. Water-borne epidemics have been reported in many developing countries primarily affecting young and middle-aged adults. To determine the role of HEV in acute sporadic NANB hepatitis, we have studied the profiles of anti-HEV IgG in the sera of patients previously diagnosed for NANB hepatitis. We tested the sera of 53 patients with acute NANB hepatitis and 100 healthy people as a control group for anti-HEV IgG. Thirty-nine of the 53 patients (73.3%) and none of the control group were positive for HEV infection, according to results shown by ELISA. This result suggests that HEV is a common cause of acute sporadic NANB hepatitis in Turkey. Further studies are needed in the other regions to determine the true prevalence of HEV infection in Turkey.