Identification and characterization of two novel genomic RNA segments RNA5 and RNA6 in rose rosette virus infecting roses.

Rose rosette virus (RRV), a negative-strand RNA virus belonging to the genus Emaravirus, has recently been characterized to be the causal agent of rose rosette disease. Roses showing typical symptoms of RRV collected from a rose nursery in Florida were subjected to reverse transcription-PCR (RT-PCR) assay using primers corresponding to the conserved inverted 13 nucleotide long stretches found at the termini of the RRV genomic RNA segments. RT-PCR analysis yielded two novel genomic RNA segments, RNA5 and RNA6, in addition to the previously identified four RNA segments. The RNA5 is 1650 bp long and encodes for a polypeptide of 465 amino acids (54.3 K), while RNA6 is 1400 bp long and encodes for a polypeptide of 233 amino acids (27.05 K). RACE analysis showed that, both the RNA segments posses at their 5' and 3' termini, stretches of conserved inverted complementary13 nucleotides long sequence with two nucleotide mismatches as previously identified in other genomic RNA segments. Northern blot analysis as well as RT-PCR using specific primers showed the presence of the novel genomic RNA segments in infected plants, but absent in the non-infected plants. The GenBank Acc. Nos. for the sequences reported in this paper are KT007556 and KT007557.

The effects of serotonin (5-HT3) receptor antagonists on gastric tachyarrhythmia and the symptoms of motion sickness.

BACKGROUND: The purpose of this study was to determine the effects of the serotonin (5-HT3) receptor-antagonist antiemetics ondansetron and granisetron on the development of gastric tachyarrhythmia, nausea, and other symptoms of motion sickness. METHODS: In a double-blind, counterbalanced, repeated measures design, 12 motion sickness susceptible college students participated in 3 sessions with an intersession interval of 1 wk. Participants received either 8 mg of ondansetron, 2 mg of granisetron, or placebo 1 h before exposure to a rotating optokinetic drum. Electrogastrograms (EGGs) were recorded during a 6-min baseline period and a subsequent 16-min drum rotation period. Subjective symptoms of motion sickness (SSMS) were obtained every 3 min during drum rotation. RESULTS: During drum rotation, gastric tachyarrhythmia increased significantly more during the placebo condition than during either of the serotonin (5-HT3) receptor antagonist conditions. However, maximum SSMS scores were not different among conditions. CONCLUSIONS: The serotonin (5-HT3) receptor antagonists inhibited the development of tachyarrhythmia, but did not prevent the development of nausea and other symptoms of motion sickness. The antiemetics ondansetron and granisetron may act as gastric anti-dysrhythmics, but their ability to arrest the development of gastric tachyarrhythmia was not sufficient for the prevention of nausea.

Facial nerve stimulation from cochlear implants.

OBJECTIVE: To evaluate the incidence of facial nerve stimulation from cochlear implants and to better define the segment of nerve being stimulated and the causes of stimulation. STUDY DESIGN: Retrospective patient case review and a temporal bone dissection study. SETTING: A tertiary care setting. PATIENTS: All patients given a cochlear implant at the Hospital of the University of Pennsylvania. This encompassed only adult patients. INTERVENTION: All patients had surgical insertion of either a 3M single channel, Nucleus 22-channel, or CLARION multichannel cochlear implant. MAIN OUTCOME MEASURES: Demonstration of facial nerve stimulation with a cochlear implant and determination of affected electrodes; measurement of electrode location and distances between the labyrinthine segment of the facial nerve and the cochlea in temporal bone dissections: and determination of the relationship between the labyrinthine facial nerve and the cochlea using computed tomography evaluation. RESULTS: The overall incidence of facial nerve stimulation using all three devices was 14% (8 of 58). Otosclerosis and otosyphilis appear to be predisposing conditions to stimulation. The mid-cochlear electrodes, located near the labyrinthine facial nerve, appear to cause stimulation of the VIIth nerve most commonly. Computed tomographic evaluation of the bone between the labyrinthine fallopian canal and the cochlea may provide some indication of potential facial nerve problems. CONCLUSION: Facial nerve stimulation from the use of cochlear implants is more prevalent in patients with otosclerosis and otosyphilis. The labyrinthine segment of the facial nerve is the most likely area being stimulated in most patients. Preoperative computed tomographic evaluation may be beneficial in determining the possibility of this problem.

Complications of frontal sinusitis in adolescents: case presentations and treatment options.

Frontal sinusitis in adolescents can be a serious condition because of the severity of potential complications and rapid progression of disease. These complications may arise as a result of extension of the infection intracranially, to the frontal bone, and to the orbit. Infection may spread hematogenously or by direct extension. A series of seven adolescent patients with complications of frontal sinusitis is presented. Surgical options are necessitated by the location and extent of infection and include trephination, frontal sinus obliteration, and craniotomy. Recent advances in endoscopic sinus surgery have provided surgeons another access to the frontal recess. However, a combined otolaryngological/neurosurgical approach is essential for patients with intracranial complications.

Menière's disease: differential diagnosis and treatment.

Menière's disease may be the underlying cause of dizziness, which is a common presenting complaint. This disease is differentiated from other causes of dizziness by its classic constellation of four symptoms; dizziness characterized as episodic spinning or whirling vertigo; fluctuating, low-frequency sensorineural hearing loss; tinnitus, and a sensation of fullness in the ear. Because these symptoms may or may not develop or occur simultaneously, a careful history and a complete physical examination are necessary for diagnosis. If Menière's disease is present but untreated for 10 or more years, hearing may deteriorate as the vertiginous episodes gradually subside. Medical management includes sodium restriction and the avoidance of caffeine, alcohol and nicotine. Diuretics, antiemetics, antidepressants and vestibular suppressants may be prescribed, and surgery may be considered in severe, unresponsive cases.

A unique temporal bone lesion resembling juvenile active ossifying myxoma.

Juvenile active ossifying fibroma (JAOF) is a lesion characterized by early age of onset, slow growth, frequent recurrence, and locally aggressive behavior. Histologically, it consists of three major components: cellular fibrous stroma, osteoid bodies, and myxomatous matrix, which may become cystic. This article describes a case of a slowly growing destructive lesion of the mastoid in a 2-year-old girl with histologic features resembling those of juvenile active ossifying myxoma (JAOM). Histologically, its prominent features were myxoid and fibromyxoid stroma with cystic areas, vascular spaces, bone, and multinucleated giant cells. This is the first pediatric temporal bone lesion with these features recorded These histologic components led to the diagnosis of JAOM of the temporal bone, probably developing in relation to the development of the mastoid air spaces.

Health risk behavioral survey from 39 juvenile correctional facilities in the United States.

PURPOSE: The study surveyed adolescents in juvenile detention facilities to determine the incidence of health risk behaviors. METHODS: A modified version of the United States Centers for Disease Control Youth Risk Behavior Surveillance System was administered to 1801 minors at 39 facilities in the United States. RESULTS: Risky behavior begins early, the initiation plateauing at age 15 or 16 years. Girls and boys reported comparable rates of drinking, binge drinking, and illicit drug use. North American Natives and those individuals who designated themselves as being other than any of the offered choices for racial designation ("Other") began drinking at earlier ages, had more binge drinking, more illegal drug use, and the most fight-related behavior. By age 12 years 62% reported onset of sexual intercourse and by age 14 years 89% were sexually active. Fighting was reported by 69% of detainees. Fight-related injuries within the past year were reported by 25% of the respondents. Nearly 47% belonged to a gang. Drug/alcohol use, fighting, and gang membership were related. Suicide was considered by 22% of the detainees, planned by 20%, tried by 16%, 8% were injured because of a suicide attempt. Younger teens (White, N.A. Natives, and "Other") had the most frequent suicide ideation. Drug/alcohol use correlated with suicidal thoughts. Onset of sexual intercourse was at an average age of 12. Multiple partners and pregnancy, was highest among blacks and "Others". Blacks had the highest sexually transmitted disease (STD) rate. Less than half of all respondents used condoms at last intercourse. STDs were related to being female, being black, and having multiple sexual partners. Pregnancy was related to multiple sexual partners and violent behavior. CONCLUSION: Male and female detainees report a high incidence and early onset of risky behaviors. N.A. Natives and those of "other" races reported the highest incidence of risk behaviors.

Phenytoin for motion sickness: clinical evaluation.

Phenytoin has previously been shown to protect against motion sickness induced by Coriolis stimulation. The purpose of our series of investigations was to investigate further the efficacy of phenytoin for motion sickness prophylaxis and to gain insight into its mechanism of action. We tested participants with electronystagmography, off-vertical rotation, sea travel, and parabolic flight after they received phenytoin or placebo. Blood levels of at least 9 micrograms/mL were found to protect against motion sickness. Electronystagmography showed significant decreases in the gain of the vestibuloocular reflex in participants receiving phenytoin. Few side effects were seen with drug levels in the 9 to 15 micrograms/mL range. Phenytoin is an effective motion sickness countermeasure that may exert its effect through a combination of central nervous system and peripheral vestibular effects.

Short latency vestibular evoked potentials.

Auditory responses, including the well-characterized auditory brainstem response, have been used extensively in clinical investigations. Evoked responses have not been adequately developed to investigate the vestibular system. The purpose of this study is to describe a new method for the evaluation of short-latency vestibular evoked potentials in human subjects. Standard ABR equipment is used, with a customized solid-state modification of the triggering mechanism. Signal averaging is used to record responses to multiple linear decelerations. Results indicate the presence of a short-latency wave, which is absent in vestibular-deficient subjects. The literature is reviewed and illustrative cases are presented. We believe vestibular evoked potentials are a promising new modality in investigation of vestibular physiology.

Squamous cell carcinoma arising in a plunging ranula.

A case report of a 36-year-old man with a plunging ranula of 15 years' duration, in which squamous cell carcinoma arose from the cyst wall, is presented. Pathogenesis and treatment of ranulas is briefly discussed.

A paraneoplastic syndrome associated with glomus tumors of the skull base? Early observations.

Independent secretion of vasoactive substances by glomus tumors of the skull base is widely recognized. Surgical removal of these tumors often results in an unexplained prolonged postoperative ileus, even in cases in which the vagus nerve is preserved. There is evidence that these tumors may secrete neuropeptides, such as cholecystokinin, in addition to catecholamines. A retrospective analysis of cases of glomus tumors of the skull base operated on at The Otology Group was carried out to correlate preoperative neuropeptide levels, vagus nerve status at surgery, and duration of postoperative ileus. High circulating levels of cholecystokinin associated with these tumors may be responsible for the unexplained phenomenon of prolonged postoperative ileus. The relevance of neuropeptides to the postoperative management of these patients is discussed. Preventive measures that may avert the potentially lethal complications of aspiration and negative nitrogen balance are described.

Can acquired immunodeficiency syndrome and Creutzfeldt-Jakob disease be transmitted via otologic homografts?

Materials commonly employed in the preparation of otologic homografts such as ethanol and formaldehyde are effective in vitro in inactivating human immunodeficiency virus (HIV). However, to our knowledge, the complete permeation of homograft materials with preservative has not been demonstrated. Ethanol and formaldehyde have not been shown to be effective in inactivating the Creutzfeldt-Jakob agent. The literature on sterilization procedures for these agents is reviewed. Standard procedures for preparation of otologic homografts are examined. It is recommended that donor HIV serologic status be determined when otologic homografts must be used. Further research is required to determine the efficacy of otologic homograft sterilization techniques against HIV and Creutzfeldt-Jakob disease.

Production of melanin precursors by a mutant of Tetrahymena thermophila.

A mutant of Tetrahymena thermophila, "pig," excretes melanin precursors into the culture medium where spontaneous polymerization to melanin occurs. The precursors, probably oxidation products of catecholamines, are produced in large amounts by the mutant by decarboxylation of tyrosine and hydroxylation of the resulting tyramine. Overproduction and excretion of precursors by the mutant appears to result from elevated specific activity of L-aromatic amino acid decarboxylase (DOPA decarboxylase) (E.C. 4.1.1.26).