Solid-state vibrational circular dichroism: Methodology and application for amphetamine derivatives

Amphetamine derivatives are considered most seized substances worldwide. In this study, solid-state vibrational circular dichroism (VCD) measurements of enantiomerically pure substances were performed for spectroscopic discrimination between (S)- and (R)-enantiomers. First, we have developed a universal experimental approach to obtain reliable and reproducible solid-state VCD spectra. First, the samples were prepared as pellets composed of mixtures of camphor as a model compound and a crystalline matrix powder. In order to obtain the best results without artifacts and with a maximum signal-to-noise ratio, the following experimental conditions were optimized: pellet thickness and diameter and sample rotation speed. The optimized parameters were then used for the analysis of amphetamine and its derivatives (methamphetamine and 3,4-methylendioxymethamphetamine). Our high-quality spectra and results suggest that solid-state VCD spectroscopy represents a cost-effective and easy-to-use method for the analysis of conformation changes and molecular packing in solid-state with potential applications in pharmaceutical and forensic practice.

Association between menthol-flavoured cigarette smoking and flavoured little cigar and cigarillo use among African-American, Hispanic, and white young and middle-aged adult smokers

OBJECTIVES

Flavour additives in cigarettes and little cigars and cigarillos (LCCs), which influence smokers' risk perceptions, may reinforce dual flavoured tobacco use. We examined the association among mentholated cigarette use, risk perceptions for flavour additives in LCCs and flavoured LCC smoking behaviour.

METHODS

Data from a national probability sample of 964 young and middle-aged adult current cigarette smokers were analysed. Multinomial logistic regression models examined the relationship among mentholated cigarette smoking, risk perceptions and current flavoured LCC use for the analytic sample and gender and race/ethnicity.

RESULTS

Daily menthol cigarette smokers, compared to occasional, non-menthol smokers, had increased odds of flavoured LCC smoking (OR=1.75, 95% CI 1.02 to 2.98). This relationship was found for males, blacks/African-Americans and Hispanics/Latinos (p<0.05). Positive perceptions of menthol-flavoured additives in LCCs was associated with increased odds of flavoured LCC use among the analytic sample, males and blacks/African-Americans (p<0.05). Positive perceptions for clove-flavoured, spice-flavoured and alcohol-flavoured additives were also associated with flavoured LCC use among the analytic sample (p<0.05).

CONCLUSIONS

Use of menthol-flavoured cigarettes and positive perceptions about menthol-flavoured and other flavour additives in LCCs may contribute to dual use with flavoured LCCs among adult cigarette smokers, specifically those from vulnerable populations.

A novel, orally active LPA(1) receptor antagonist inhibits lung fibrosis in the mouse bleomycin model

BACKGROUND AND PURPOSE

The aim of this study was to assess the potential of an antagonist selective for the lysophosphatidic acid receptor, LPA(1), in treating lung fibrosis We evaluated the in vitro and in vivo pharmacological properties of the high affinity, selective, oral LPA(1)-antagonist (4'-{4-[(R)-1-(2-chloro-phenyl)-ethoxycarbonylamino]-3-methyl-isoxazol-5-yl}-biphenyl-4-yl)-acetic acid (AM966).

EXPERIMENTAL APPROACH

The potency and selectivity of AM966 for LPA(1) receptors was determined in vitro by calcium flux and cell chemotaxis assays using recombinant and native cell cultures. The in vivo efficacy of AM966 to reduce tissue injury, vascular leakage, inflammation and fibrosis was assessed at several time points in the mouse bleomycin model.

KEY RESULTS

AM966 was a potent antagonist of LPA(1) receptors, with selectivity for this receptor over the other LPA receptors. In vitro, AM966 inhibited LPA-stimulated intracellular calcium release (IC(50)= 17 nM) from Chinese hamster ovary cells stably expressing human LPA(1) receptors and inhibited LPA-induced chemotaxis (IC(50)= 181 nM) of human IMR-90 lung fibroblasts expressing LPA(1) receptors. AM966 demonstrated a good pharmacokinetic profile following oral dosing in mice. In the mouse, AM966 reduced lung injury, vascular leakage, inflammation and fibrosis at multiple time points following intratracheal bleomycin instillation. AM966 also decreased lactate dehydrogenase activity and tissue inhibitor of metalloproteinase-1, transforming growth factor beta1, hyaluronan and matrix metalloproteinase-7, in bronchoalveolar lavage fluid.

CONCLUSIONS AND IMPLICATIONS

These findings demonstrate that AM966 is a potent, selective, orally bioavailable LPA(1) receptor antagonist that may be beneficial in treating lung injury and fibrosis, as well as other diseases that are characterized by pathological inflammation, oedema and fibrosis.

The dynamic nature of group A streptococcal epidemiology in tropical communities with high rates of rheumatic heart disease

Prospective surveillance was conducted in three remote Aboriginal communities with high rates of rheumatic heart disease in order to investigate the epidemiology of group A beta-haemolytic streptococci (GAS). At each household visit, participants were asked about sore throat. Swabs were taken from all throats and any skin sores. GAS isolates were emm sequence and pattern-typed using standard laboratory methods. There were 531 household visits; 43 different emm types and subtypes (emmST) were recovered. Four epidemiological patterns were observed. Multiple emmST were present in the population at any one time and household acquisition rates were high. Household acquisition was most commonly via 5- to 9-year-olds. Following acquisition, there was a 1 in 5 chance of secondary detection in the household. Throat detection of emmST was brief, usually <2 months. The epidemiology of GAS in these remote Aboriginal communities is a highly dynamic process characterized by emmST diversity and turnover.

Molecular typing of Streptococcus pyogenes from remote Aboriginal communities where rheumatic fever is common and pyoderma is the predominant streptococcal infection

Aboriginal Australians in remote communities have high rates of rheumatic heart disease (RHD); yet pharyngitis is reportedly rare whilst pyoderma is common. Some strains of group A streptococci (GAS) have preference for the throat and others for the skin depending on M protein type. A study in three remote communities provided 350 GAS isolates for emm sequence typing, 244 were also emm pattern typed. There was 100% correlation between emm sequence and pattern type. Patterns D and E (non-throat tropic) made up 71% of throat and 87% of skin isolates although patterns A-C (throat tropic) were more common in the throat than the skin (RR 2.3, 95% CI 1.4-3.8) whilst the opposite was found for pattern D (RR 2.2, 95% CI 1.7-3.0). Pattern E favoured the throat (RR 1.4, 95% CI 1.1-1.8). Where environmental factors predispose to skin infection, emm pattern types D and E prevail, whatever the recovery site.

Reduction meatoplasty with a post-auricular island flap

The importance of an adequate meatoplasty is often emphasised in mastoid surgery. However, bigger is not always better, as an excessively widened external meatus can be cosmetically unacceptable, provide little extra benefit for cleaning, be an obstacle to the good fitting of hearing aids and expose the mastoid cavity to exaggerated caloric effect.

The problems created by an overly large meatus can occasionally be difficult to manage, prompting consideration of reduction of the meatus. We describe the use of a pedicled, post-auricular skin flap to achieve reduction of an excessively large meatus.

Locating the scala media in the fixed human temporal bone for therapeutic access: a preliminary study

Objective: To investigate the location of the scala media in relation to the round window niche in human temporal bones.

Design: Ten human temporal bones were investigated by radical mastoidectomy and promontory drill-out.

Setting: Temporal bone laboratory.

Outcome measures: The distance from the scala media to the anterior edge of the round window niche, measured by Fisch's stapedectomy measuring cylinders.

Results: The scala media was identified at the transection point of a vertical line 1.6 to 2.2 mm (mean=1.8 mm; standard deviation=0.2) anterior to the anterior edge of the round window niche and a horizontal line 0.2 mm inferior to the lower border of the oval window.

Conclusion: This report demonstrates the point of entry into the scala media via the promontory in fixed temporal bone models, which may provide a site of entry for stem cells and gene therapy insertion.

Facial nerve schwannoma: surgical excision versus conservative management

Facial nerve schwannomas are slow-growing tumors that may involve any part of the facial nerve. When they present with moderate to total facial palsy, complete resection is clearly indicated. However, in cases with mild or no facial dysfunction, the best course of treatment is less obvious. A series of 22 patients with facial nerve schwannoma is presented, of whom 12 underwent definitive excision and 10 were managed more conservatively. The best postoperative facial function in the group who had tumor removal was a House-Brackmann grade III, while 8 of the conservatively treated group had normal facial function up to 10 years after presentation. As well, no significant tumor growth was noted on serial radiologic imaging of those being observed. Delaying surgical resection of facial nerve schwannomas may allow patients to retain normal facial function indefinitely.

Social influences, social norms, social support, and smoking behavior among adolescent workers

PURPOSE

To examine the relationships between worksite interpersonal influences and smoking and quitting behavior among adolescent workers.

DESIGN

The cross-sectional survey assessed factors influencing tobacco use behavior.

SETTING

During the fall of 1998, data were collected from 10 grocery stores in Massachusetts that were owned and managed by the same company.

SUBJECTS

Eligible participants included 474 working adolescents ages 15 to 18. Eighty-three percent of workers (n = 379) completed the survey.

MEASURES

The self-report questionnaire assessed social influences, social norms, social support, friendship networks, stage of smoking and quitting behavior, employment patterns, and demographic factors.

RESULTS

Thirty-five percent of respondents were never smokers, 21% experimental, 5% occasional, 18% regular, and 23% former smokers. Using analysis of variance (ANOVA), results indicate that regular smokers were 30% more likely than experimental or occasional smokers to report coworker encouragement to quit (p = .0002). Compared with regular smokers, never smokers were 15% more likely to report greater nonacceptability of smoking (p = .01). chi 2 tests of association revealed no differences in friendship networks by stage of smoking.

CONCLUSIONS

These data provide evidence for the need to further explore social factors inside and outside the work environment that influence smoking and quitting behavior among working teens. Interpretations of the data are limited because of cross-sectional and self-report data collection methods used in one segment of the retail sector.

Canalplasty: review of 100 cases

Canalplasty is the surgical procedure whereby the external auditory meatus is widened. The indications include exostoses, stenosing external otitis and widening for surgical access. One hundred consecutive ears operated on by one surgeon are reported. The surgical technique is described in detail, paying particular attention to bone removal from the anterior canal wall. In this paper the majority of cases were occasioned by soft tissue rather than bony stenosis. The re-stenosis rate was four per cent and in each case this was associated with the use of a middle temporal artery flap. Partial, transient, delayed facial palsy occurred in two per cent, probably relating to thermal injury transmitted from the burr. A full, spontaneous recovery of facial function occurred in each case. This is a safe and effective technique for canal widening.

Multichannel auditory brainstem implantation: the Australian experience

The multichannel auditory brainstem implant (ABI) provides the potential for hearing restoration in patients with neurofibromatosis type 2 (NF2). Programmes for auditory brainstem implantation have been established in two Australian centres. Eight patients have been implanted under the protocol of an international multi-centre clinical trial. Three patients had ABI insertion at the time of first side tumour removal, four at second side tumour removal and one after previous bilateral surgery where there was some residual tumour. The translabyrinthine approach was used in all cases. Successful positioning of the electrode array was achieved in seven of eight patients, all of whom achieved auditory perception with electrical stimulation. Intra-operative electrically evoked auditory brainstem response testing was successful in four patients and was useful in confirming correct electrode position. In six cases post-operative psychophysical and auditory perception testing demonstrated that useful auditory sensations were achieved. Five of these patients regularly used the implant. In one patient electrode placement was unsuccessful and only non-auditory sensations occurred on stimulation. In the remaining patients non-auditory sensations were minimal and avoidable by selective electrode programming. Auditory brainstem implantation should be considered in patients with NF2. The greatest benefit is seen in patients without debilitating disease who have non-aidable hearing in the contralateral ear.

Galvanic stimulation evokes short-latency EMG responses in sternocleidomastoid which are abolished by selective vestibular nerve section

OBJECTIVE

To describe vestibulocollic responses in sternocleidomastoid (SCM) evoked by transmastoid galvanic (DC) stimulation.

METHODS

We studied the averaged responses in the unrectified EMG of SCM to transmastoid galvanic stimulation (5 mA/2 ms) and also to 100 dB clicks. Two patients with Meniere's disease were studied both before and after unilateral selective vestibular nerve section.

RESULTS

Transmastoid galvanic stimulation produced a positive-negative biphasic EMG response at short latency in the SCM ipsilateral to the side of cathode placement, which resembled that which followed vestibular activation by loud clicks (p13/n23). Selective unilateral vestibular nerve section abolished this galvanic-evoked response.

CONCLUSIONS

Galvanic-evoked vestibulocollic responses can be recorded in SCM. This is a new method of studying vestibular reflex function which may have application in the clinical assessment of vestibular disorders.

Unusual lesions of the internal auditory canal

Acoustic neuromata (AN) account for nearly 90 per cent of internal auditory canal (IAC) and cerebello-pontine angle (CPA) tumours. The second most common tumour is meningioma. Rare lesions include primary cholesteatoma, facial neuroma, lipoma, angioma and various cysts. Two cases of IAC tumour are presented, one of hamartoma in which smooth muscle was prominent and the other of lymphangioma. Of interest are the specific clinical and radiological features associated with these lesions.

Cultural sensitivity and readability of breast and prostate printed cancer education materials targeting African Americans

Cancer prevention materials such as pamphlets, booklets, and fact sheets play a significant role in reducing cancer disparities. Little is documented in the literature about the cultural sensitivity of materials targeting African Americans. The Cancer Prevention Materials and African Americans project was conducted to assess the cultural sensitivity and readability of printed cancer education materials targeting African Americans. Results showed current breast and cancer materials are not written at appropriate reading levels, and only 54% of the breast and 40% of the prostate cancer materials were found to be culturally sensitive. Even though the materials are being developed and disseminated in health fairs, physician offices, barber shops, and other locations, the materials are still not reflective of the African-American populations and do not consider literacy, visual, written messages, and format as factors in their utilization. Future studies should assess the appropriateness of materials for African Americans to promote and prevent cancer in African Americans.

Actinomycosis oto-mastoiditis

Actinomycosis of the temporal bone is uncommon. There have only been 24 cases previously reported in the English literature. The responsible organism is Actinomyces israelii, an anaerobic filamentous Gram positive bacterium. While the cervico-facial region is the most common site of the disease, involvement of the temporal bone is rare. The diagnosis can sometimes be made clinically by identification of sulphur granules in a glue-like substrate but in all cases involving the temporal bone, the diagnosis has been made at histopathology. Effective therapy consists of surgery followed by the long-term administration of penicillin.

Drill-induced hearing loss in the nonoperated ear

The reversible hearing loss in the nonoperated ear noted by patients after ear surgery remains unexplained. This study proposes that this hearing loss is caused by drill noise conducted to the nonoperated ear by vibrations of the intact skull. This noise exposure results in dysfunction of the outer hair cells, which may produce a temporary hearing loss. Estimations of outer hair cell function in the nonoperated ear were made by recording the change in amplitude of the distortion-product otoacoustic emissions before and during ear surgery. Reversible drill-related outer hair cell dysfunction was seen in 2 of 12 cases. The changes in outer hair cell function and their clinical implications are discussed.

Schwannoma in the vestibule and cochlea

Schwannoma of the vestibule or the cochlea is an unusual lesion. In the past, most examples have been found at autopsy or as unsuspected findings at surgery for vertigo. The symptoms of isolated labyrinthine schwannoma may be indistinguishable from advanced Meniere's disease. Magnetic resonance imaging has led to pre-operative diagnosis in some cases. Two cases of schwannoma within the labyrinth from a series of 339 symptomatic acoustic tumours, are presented and the imaging findings are discussed.

The readability levels of cancer-prevention materials targeting African Americans

BACKGROUND

Several studies have examined the readability levels of cancer-prevention materials, but the readability levels of materials targeting African Americans have not been documented. The Cancer Prevention Materials and African-Americans project, funded in 1994 by the Texas Cancer Council, was developed to assess the readability levels and cultural sensitivity of cancer-prevention materials targeting African Americans.

METHODS

This study assessed the readability of 100 cancer-prevention materials using McLaughlin's SMOG grading. Illustrations and point sizes were also examined by research staff members.

RESULTS

Seventy-two percent of the material contained illustrations and 88% were printed using a 12-point font. An overall mean SMOG grade of 9.32 was found, which suggests that ninth graders can read and comprehend the text.

CONCLUSIONS

Although this grade level is lower than those indicated by previous studies, many of the printed materials may not be appropriate for African Americans at high risk for cancer: those with low incomes and little education. Health professionals should focus on decreasing the reading levels of print materials, pretesting audiences to determine their actual reading levels, and examining other factors that influence readability and comprehension.

Episodic facial paralysis due to temporal bone pneumocele: a case report

A case of episodic facial paralysis resulting from a pneumocoele of the temporal bone is presented. The patient had undergone facial nerve exploration and blind sac closure after a transverse fracture of the petrous temporal bone.

Vestibular schwannoma in an only hearing ear

A vestibular schwannoma in an only hearing ear is a difficult management problem. A case is presented of a patient who had a Nucleus-22 channel device implanted into a nonfunctioning ear and auditory rehabilitation prior to resection of a large vestibular schwannoma in the contralateral ear.

A simple method for N-15 labelling of exocyclic amino groups in synthetic oligodeoxynucleotides

The use of the ammonia deprotection step to introduce (15)N labels at specific exocyclic amino positions of adenine, cytosine, guanine or 2-aminopurine of oligodeoxynucleotides is described.

The bony crescent sign--a new sign of facial nerve schwannoma

Schwannomas of the facial nerve are rare slowly growing lesions that have a predilection for the geniculate ganglion. Radiological evaluation is important in their diagnosis and in the assessment of their extent. In our series of 4 cases the facial nerve schwannoma was seen on high resolution CT as a soft tissue mass bounded anteriorly by a thin rim of bone. This bony crescent sign is a previously undescribed sign of facial nerve schwannoma which appears on the basis of this small series to be strongly indicative of the presence of this tumour. Schwannomas are relatively uncommon intracranial tumours. They most commonly involve the acoustic nerve followed in frequency by the trigeminal nerve. Other cranial nerves are rarely involved. Facial nerve schwannomas occurring within the petrous temporal bone are very rare. Their diagnosis may be missed prospectively even when appropriate CT scans are performed. Even in retrospect the site of abnormality may be difficult to identify, especially if there is an associated middle ear mass such as a cholesteatoma. Lesions occurring in the petrous area are all rare. The differential diagnosis includes cholesterol granuloma, epidermoid, carotid aneurysm and, very rarely, primary and secondary bone tumours. We describe a new sign associated with facial nerve schwannoma on CT, that of a bony crescent. Recognition of this sign makes those tumours arising in the region of the geniculate ganglion easy to diagnose prospectively.

NMR structural refinement of a tandem G.A mismatched decamer d(CCAAGATTGG)2 via the hybrid matrix procedure

A complete relaxation matrix approach employing a matrix eigenvalue/eigenvector solution to the Bloch equations is used to evaluate the NMR solution structure of a tandemly positioned G.A double mismatch decamer oligodeoxyribonucleotide duplex, d(CCAAGATTGG)2. An iterative refinement method using a hybrid relaxation matrix combined with restrained molecular dynamics calculations is shown to provide structures having good agreement with the experimentally derived structures. Distances incorporated into the MD simulations have been calculated from the relaxation rate matrix evaluated from a hybrid NOESY volume matrix whose elements are obtained from the merging of experimental and calculated NOESY intensities. Starting from both A- and B-DNA and mismatch syn and anti models, it is possible to calculate structures that are in good atomic RMS agreement with each other (less than 1.6 A RMS) but differ from the reported crystal structure (greater than 3.6 A). Importantly, the hybrid matrix derived structures are in excellent agreement with the experimental solution conformation as determined by comparison of the 200-ms simulated and experimental NOESY spectra, while the crystallographic data provide spectra that are grossly different.

Magnetic resonance imaging evaluation of cerebellopontine angle tumours

In the evaluation of tumours of the cerebellopontine angle MRI has a sensitivity and a specificity slightly greater than that of CT. At present it does not appear justified to displace CT as the standard means of investigation of a CPA tumour. The role of MRI is analagous to that of air-CT.

Sinus barotrauma in divers

Sinus barotrauma is a common occupational disease of divers, with the incidence of descent barotrauma approximately double that of ascent. Pain chronologically associated with the change of pressure is the most dominant symptom and is seen in 92% of the cases presented for treatment. The majority complain of a frontal distribution of pain, with ethmoidal and maxillary being much less significant. Epistaxis is the second commonest symptom, and may be the sole symptom in some ascent cases. A history of recent or past sinus barotrauma or upper respiratory tract pathology is very common. Clinical examination supports the evidence of upper respiratory tract pathology in many cases. The radiological signs of abnormality were present in over three quarters of the cases examined. Of these the maxillary sinus was affected in most cases, the frontal in approximately one quarter and the ethmoidal in less than a fifth. The pathology was more commonly that of mucosal thickening, but in 12% of cases there was a fluid level. It is noted that although symptoms were predominantly frontal, x-ray changes were most often present in the maxillary sinuses.

Rupture of the round window membrane

A perilymph leak into the middle ear through a ruptured round window membrane results in the symptoms of hearing loss, tinnitus and vertigo, either singly or in combination. The case histories of thirteen patients with such a fistula are described, these patients having in common a predisposing incident which had led to a rise of C.S.F. pressure. Symptomatology and the results of investigation are analysed and operative technique and results discussed. While it appears that vertigo uniformly responds very satisfactorily to operative treatment the improvement in hearing loss and tinnitus is more difficult to predict.