Biomedical subjects
Publications and source records attributed to J C Lowry.
Tracheostomy is frequently required during maxillofacial procedures. The percutaneous technique is described and advocated as a rapid easily mastered procedure, although there is a definite learning curve and it is not without a potential for complications.
A case of an intraoral inflammatory pseudotumor is described. Although this lesion has been reported to occur in the oral cavity, no cases have been documented in the literature. Difficulties were encountered in arriving at a diagnosis in a patient with a condition in the mandible.
The argon laser was used to treat trichiasis in 44 patients over a five-year period. During follow-up intervals of between one month and more than four years (mean, 13 months), ablation of misdirected cilia was accomplished with one treatment in 26 patients (59%). No complications were observed. Laser is less effective than cryotherapy for destroying aberrant eyelashes, but cryotherapy is less precise and incites greater posttreatment inflammation. Argon laser treatment is a useful option when only a few, scattered eyelashes require ablation or in patients with disorders such as ocular pemphigoid, in which the stimulation of inflammation is undesirable.
We performed serial slit-lamp examinations and topography analysis on a patient whose initial topographic map suggested a diagnosis of keratoconus to us but which others interpreted as normal topography. Topography analysis documented cone progression during a two-year period. The initial map showed a cone apex power of 44.5 diopters located 2.1 mm inferior to the vertex normal. An oblong-shaped area of maximum power was surrounded by concentric bands of lower power. Corneal surface power ranged from 41.5 to 44.5 diopters. Two years later cone apex power increased to 51.0 diopters, and the patient developed a Fleischer's ring, Vogt's striae, and mild visual aberration. Our findings suggest the use of topography analysis systems in documenting subclinical cone progression. Topography systems may be a useful tool in the study of the true incidence and natural progression of subclinical keratoconus.
Fifteen years ago when the expenditure on the National Health Service was 2600 million pounds annually, an economic survey of the then more common procedures carried out by oral and maxillofacial surgeons in the UK was undertaken. After three reorganisations of the NHS with a fourth pending the overall cost has escalated to 21.6 billion pounds. The specialty has also seen significant change with a broader spectrum of work being carried out and a greater proportion of major cases being undertaken. The paper shows how previously costed procedures have changed; for example with increasing use of day care facilities and internal fixation techniques, before moving on to consider costings for the more advanced operations now being carried out on a regular basis. In an era of resource management with progressive stringency of funding in the acute sector it has been suggested that some procedures are uneconomical and others possibly should not take high priority. Under these circumstances it has become especially important to justify all facets of practice of the specialty and this aspect is considered in terms of the cost to the National Health Service, the quality of life of the patient and the cost to the economy as a whole in Social Security benefits and loss of productivity.
We report the results of a nonrandomized, matched group survival study comparing 29 patients with a choroidal or ciliary body melanoma managed by enucleation alone to 29 patients managed by enucleation following external beam ocular irradiation (20 Gy in five fractions over 5-7 days just prior to enucleation). Variables on which the patients in the two groups were matched included age at time of enucleation, largest linear tumor dimension, location of the anterior tumor margin relative to the equator and ora serrata, melanoma cell type, and extrascleral tumor extension. The cumulative 5-year survival in the enucleation alone group was 57.9% (SE = 9.9%), whereas that in the preenucleation radiation therapy group was 63.9% (SE = 12.2%). This difference is not statistically significant (p greater than 0.5, Mantel-Haenszel test). The authors discuss the strengths and limitations of their study and the implications of their results.
We report the results of a nonrandomized, matched-group, survival and visual preservation study of patients with a choroidal or ciliary body melanoma managed by microsurgical resection of the tumor versus cobalt-60 episcleral plaque radiotherapy. Each treatment group consisted of 30 patients. All patients were matched on a case-by-case basis in terms of tumor size (largest linear tumor dimension), location of the anterior tumor margin relative to the ora serrata, location of the posterior tumor margin relative to the equator, and age at the time of treatment. Although the estimated actuarial 5-year survival probability was slightly greater in the resection group (85.2%) than in the cobalt plaque group (81.8%), this difference was neither clinically impressive nor statistically significant. In contrast, there was a substantially higher rate of early posttreatment severe visual loss in the resection group (P = .0008, Mantel-Haenszel test).
A case of mucoepidermoid tumour arising in minor salivary glands of the tongue and assessed histologically to be of high-grade malignancy is described. The diagnostic difficulties involved in distinguishing the neoplasm from a squamous cell carcinoma are considered. From published figures it would appear that salivary gland neoplasms in the tongue are much more likely to be malignant than benign.
Sea urchin (S. purpuratus) histone DNA of constructed plasmid chimeras cloned in E. coli was cleaved with the restriction endonucleases Eco RI, Hind III, Sal I. Bam I, and Hha I. The resulting fragments were ordered and isolated directly from agarose gels or cloned into other plasmids. Each fragment hybridized to one or another of the five histone mRNAs and elucidated the order of the histone genes in each of the cloned fragments. Some DNA did not hybridize to histone mRNAs and was identified as spacer DNA located between coding regions. Total sea urchin DNA was cleaved with restriction endonucleases, fractionated on agarose gels, and hybridized to histone mRNAs or histone DNA. The results revealed the order of the five histone genes in the histone gene repeat unit and demonstrate that the histone spacer DNA have little sequence homology to other genes. ExonucleaseIII digestion of specific linear chimeric histone DNA plasmids followed by hybridization with mRNAs demonstrated the existence of all five histone genes on one strand of DNA and the 5'-3' polarity of that strand. These results, in conjunction with the data of Wu et al. (1976), allow us to construct a map of coding and spacer sequences in the transcribed strand of S. purpuratus histone gene repeat unit: (see article).
Sucrose gradient analysis of total sea urchin DNA cleaved with the EcoRI and Hind III restriction endonucleases and identification of histone coding gene sequences by hybridization with histone mRNA have elucidated the basic organization of the histone gene repeat unit. These data, plus results obtained by electrophoretic analysis of purified endonuclease-cleaved sea urchin histone DNA and hybridization with cRNA transcribed from the eucaryotic segment of constructed plasmid chimeras cloned in E. coli, show that the several DNA sequences coding for individual histone proteins are intermingled in a 7 kilobase (kb) repeat unit. Cleavage of total sea urchin DNA with EcoRI produces 2.2 and 4.8 kb fragments, and which are contained in a 7 kb Hind III fragment. Cleavage with both enzymes reveals that the 2.2 kb EcoRI fragment contains a Hind III site 0.15--0.2 kb from an end. RNA.DNA hybridization between chimeric palsmic DNA and purified individual mRNAs isolated from sea urchin embryo polyribosomes has been used to assign coding sequences to either the 2.2 or 4.8 kb region of the histone DNA repeat unit. A map of the histone genes is proposed.
A case of psoriatic arthritis involving a TMJ and several peripheral joints is reported and discussed.
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Although blepharoplasty is a technically straightforward procedure, many postoperative complications may occur. Some of the untoward effects may be only a transient nuisance for the patient, such as mild ocular dryness, whereas other sequelae can lead to severe visual loss. An extensive review of the prevention, diagnosis, and management of complications associated with blepharoplasty is presented.
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