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J M Cole

Publications and source records attributed to J M Cole.

At least 19 recordsLinked to original sources
PubMed2001

Rapid neutron-diffraction data collection for hydrogen-bonding studies: application of the Laue diffractometer (LADI) to the case study zinc (tris)thiourea sulfate.

The successful application of the newly developed image-plate neutron Laue diffractometer (LADI) at the Institut Laue-Langevin (ILL), Grenoble, France, for rapid hydrogen-bonding characterization is reported. The case study concerns the promising non-linear optical material zinc (tris)thiourea sulfate (ZTS), which contains 30 atoms in the asymmetric unit and crystallizes in the orthorhombic space group, Pca2(1), a = 11.0616 (9), b = 7.7264 (6), c = 15.558 (1) A [T = 100.0 (1) K]. The results from a 12 h data collection from ZTS on LADI are compared with those obtained over 135 h using the monochromatic four-circle diffractometer D9 at the same reactor source with a crystal 13 times larger in volume. Both studies reveal the extensive hydrogen bonding and other close non-bonded contacts within the material. As expected, the results from D9 are more precise than those obtained from LADI; however, the bond geometry determined from the two experiments is the same within the larger estimated standard deviations. Furthermore, the conclusions drawn from the two studies separately regarding the nature of all supramolecular features are identical. This illustrates that LADI is eminently suitable for rapid characterization of hydrogen-bonded structures by neutron diffraction, with the gain in speed compared with traditional instrumentation being several orders of magnitude.

Journal Article↗
PubMed2001

Influence of hydrogen bonding on the second harmonic generation effect: neutron diffraction study of 4-nitro-4'-methylbenzylidene aniline.

A neutron diffraction study of the non-linear optical (NLO) material 4-nitro-4'-methylbenzylidene aniline (NMBA) is presented. NMBA exhibits a large macroscopic second-order NLO susceptibility, chi((2)), and this study shows that hydrogen bonding is, in part, responsible for this. No hydrogen bonding was reported in the X-ray study [Ponomarev et al. (1977). Sov. Phys. Crystallogr. 22, 223-225], whereas the present work shows that C-H.X hydrogen bonds (where X = N, O or pi) direct the nature of the three-dimensional lattice. C-H.X (X = N or O) hydrogen bonds are common; however, C-H.pi hydrogen-bond motifs are relatively rare. Such intermolecular interactions help extend the molecular charge transfer into the supramolecular realm, the charge transfer originating as a consequence of the high level of molecular planarity and strong donor-to-acceptor interactions. Molecular planarity, coupled with the favourable nature of the hydrogen bonds, results in parallel stacking of molecules in both the a and c crystallographic directions with extremely close interplanar spacings. Such a combination of influential hydrogen-bonding characteristics accounts, in part, for the large second-order NLO output of the material since the phenomenon is so critically dependent upon the nature of the charge transfer.

Journal Article↗
PubMed1996

Long-term follow-up of stapedectomy in children and adolescents.

Otosclerosis presenting in children and adolescents is uncommon. Typically, otosclerosis presents as a slowly progressive conductive hearing loss in the third to fourth decade. Many well-documented studies have demonstrated excellent long-term hearing results with stapedectomy. Although stapedectomy is highly effective, the rare complications may be devastating. Thirty-one patients, 21 years or younger, underwent 40 stapedectomies for otosclerosis at our institution. The average age at surgery was 16 years, with a range of 7 to 21 years. Postoperative results showed an average improvement in air-bone gap of 22 dB. Clinical and audiologic data were collected over a mean follow-up period of 25 years. There was no statistically significant difference in air-bone gap when comparing the immediate postoperative gap (measured 2 months after stapedectomy) with the last gap recorded (mean, 25 years after stapedectomy). Fifty percent of the ears operated on maintained an air-bone gap within 10 dB at the last follow-up, and an additional 40% maintained a 10- to 20-dB gap. There were no significant relationships between demographic or clinical factors and "success" (gap <= 10 dB) or long-term gap closure. Our data demonstrate that stapedectomy is an effective method for closing the air-bone gap in children and adolescents with otosclerosis, and long-term results parallel those of adults, showing maintenance of excellent gap closure. This review represents the largest population with the longest follow-up in children who underwent stapedectomy for the treatment of otosclerosis.

Adolescent↗
PubMed1994

Long-term results of treatment for glomus jugulare and glomus vagale tumors with radiotherapy.

Since 1954, 39 cases of glomus jugulare or vagale tumor have been treated by the authors with radiotherapy. The initial results with orthovoltage (280 kV) therapy were unpredictable, but 30 patients with 32 tumors treated with megavoltage radiotherapy (Cobalt-60 [60Co] or linear accelerator) have shown either no evidence of recurrence or complications, with one exception, or died of causes unrelated to their glomus tumor. Megavoltage radiotherapy is recommended for primary treatment of all glomus tumors that present with evidence of bone invasion or nerve involvement.

Adult↗
PubMed1990

Primary cutaneous neuroendocrine carcinoma (Merkel cell tumor). An adnexal epithelial neoplasm.

We report 18 cases of primary cutaneous neuroendocrine carcinoma (CNEC, Merkel cell tumor) that occurred mainly in the sun-exposed skin of elderly patients as dermal and subcutaneous masses of generally monomorphic cells with foci of pronounced pleomorphism. All 18 cases showed immunoreactivity for neuron-specific enolase (NSE), whereas 16 of them showed immunoreactivity for another neuroendocrine marker, protein gene product 9.5 (PGP 9.5). Positivity for PGP 9.5 was more intense and more sharply localized to tumor cells than the staining for NSE. Immunoreactivity for keratins detected by AE1/AE3 and CAM 5.2 monoclonal antibodies was found in 16 and 15 cases, respectively, with prominent paranuclear globular staining. One case stained positively for S-100 protein; all were negative for leukocyte common antigen (LCA). Typical ultrastructural features of neuroendocrine differentiation were noted in all of 14 tumors examined. Morphological and immunohistochemical similarities between these neoplasms and pulmonary small-cell anaplastic carcinoma, now thought to be of bronchial basal cell origin, suggest that CNEC are also derived from epithelium. In addition, their dermal location suggests that this epithelium is likely to be adnexal rather than epidermal.

Adnexal Diseases↗
PubMed1989

Results of surgical treatment for Menière's disease.

In 1985 the American Academy of Otolaryngology-Head and Neck Surgery Committee on Hearing and Equilibrium established revised guidelines for reporting treatment results for Menière's disease. Since then little information regarding the newly adapted criteria and their effects on the evaluation process has appeared. Thus we compared the results of different surgical procedures for Menière's disease using both the 1985 and 1972 guidelines. One hundred nine surgical procedures from 1969 to 1985 were reviewed. Six different surgical procedures were evaluated: the Cody-Tack, cochleosacculotomy, endolymphatic mastoid shunt, endolymphatic subarachnoid shunt, translabyrinthine vestibular nerve section, and transcanal labyrinthectomy. Results show that 68% of patients who had a Cody-Tack procedure continued to have vertiginous episodes in the same frequency postoperatively. Hearing was worse in 17 of these 25 patients. Of the patients who had a cochleosacculotomy, most had significant control of their vertiginous symptoms, but 10 patients had greater than 10 dB hearing loss postoperatively. Patients who had an endolymphatic mastoid shunt performed had better results when the 1972 guidelines were applied. In this group, the 1985 guidelines indicate that only 35% of the patients had significant relief of their vertiginous symptoms and 47% had hearing loss greater than 10 dB postoperatively. Six of the seven patients who underwent an endolymphatic subarachnoid shunt obtained significant relief of their vertiginous episodes, but hearing loss was more than 10 dB in four patients. Those patients who had either a labyrinthectomy or a translabyrinthine vestibular nerve section had relief of their vertiginous episodes. We conclude that the new guidelines appear to be superior to the 1972 guidelines for reporting results for the treatment of Menière's disease.

Auditory Threshold↗
PubMed1982

Labyrinthectomy.

Explore the source record for details and available documents.

Ear, Inner↗
PubMed1979

Panel discussion: glomus jugulare tumors of the temporal bone. Radiation of glomus tumors of the temporal bone.

In a study done at the Geisinger Medical Center in 1976, the results of treatment of 30 cases of glomus tumors involving the ear were reviewed. All 8 cases of glomus tympanicum were controlled with surgery and all of the cases of glomus jugulare treated with high voltage radiotherapy were controlled for from 2 to 12 years. Currently, the length of control extends to 15 years and there have been no late recurrences. Three additional cases showing unusual features of glomus jugulare are presented.

Adult↗
PubMed1979

Long-term effect of otosclerosis on bone conduction.

There have not been many studies of long-term sensorineural function in otosclerosis. The reports of long-term follow-up of lateral canal fenestration cases show a surprising stability of bone conduction. Because the experience of the senior author in stapes surgery suggests that some patients with clinically proven otosclerosis have a tendency for progression of sensorineural hearing loss, a review of over 500 ears in patients with proven otosclerosis was undertaken. Data from the study indicate that patients with otosclerosis have more sensorineural hearing loss than the general population. Also some otosclerotic ears have a tendency for progression of sensorineural hearing loss.

Audiometry↗
PubMed1977

Glomus jugulare tumor.

A review has been made of the current recommendations for treatment of glomus tumors involving the ear. Thirty cases treated in our clinic have been reviewed, comprised of 8 glomus tympanicum and 22 glomus jugulare tumors. We recommend surgical excision as primary treatment for glomus tympanicum tumors and high voltage radiotherapy as primary treatment for glomus jugulare tumors. Visible residual tumor following adequate radiotherapy may remain unchanged for many years. Some cases that do not show a response to high voltage radiation may be suitable for secondary radical surgical treatment. Fortunately, we have not yet encountered a case of glomus jugulare tumor with nonresponse to high voltage radiation in the doses recommended. Long term follow-up is important.

Adult↗