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Biomedical subjects

A Jefferson

Publications and source records attributed to A Jefferson.

18 recordsLinked to original sources
PubMed2004

Unexpected complexity in the haplotypes of commonly used inbred strains of laboratory mice.

Investigation of sequence variation in common inbred mouse strains has revealed a segmented pattern in which regions of high and low variant density are intermixed. Furthermore, it has been suggested that allelic strain distribution patterns also occur in well defined blocks and consequently could be used to map quantitative trait loci (QTL) in comparisons between inbred strains. We report a detailed analysis of polymorphism distribution in multiple inbred mouse strains over a 4.8-megabase region containing a QTL influencing anxiety. Our analysis indicates that it is only partly true that the genomes of inbred strains exist as a patchwork of segments of sequence identity and difference. We show that the definition of haplotype blocks is not robust and that methods for QTL mapping may fail if they assume a simple block-like structure.

Alleles↗
PubMed2004

Mapping of three translocation breakpoints associated with orofacial clefting within 6p24 and identification of new transcripts within the region.

Orofacial clefting (OFC) is a common congenital malformation. Here we report the refinement of three translocation breakpoints of patients exhibiting OFC within the 6p24 region, and the isolation and characterisation of novel genes, one of which is directly disrupted by the translocation breakpoint of a patient. The gene has been characterized and orthologues identified in bovine, murine and pufferfish.

Animals↗
PubMed2001

The Indian Ocean experiment: widespread air pollution from South and Southeast Asia.

The Indian Ocean Experiment (INDOEX) was an international, multiplatform field campaign to measure long-range transport of air pollution from South and Southeast Asia toward the Indian Ocean during the dry monsoon season in January to March 1999. Surprisingly high pollution levels were observed over the entire northern Indian Ocean toward the Intertropical Convergence Zone at about 6 degrees S. We show that agricultural burning and especially biofuel use enhance carbon monoxide concentrations. Fossil fuel combustion and biomass burning cause a high aerosol loading. The growing pollution in this region gives rise to extensive air quality degradation with local, regional, and global implications, including a reduction of the oxidizing power of the atmosphere.

Aerosols↗
PubMed1996

Patients with recurrent renal stones have a physico-chemically altered urinary Tamm-Horsfall glycoprotein profile.

We describe an immunoblotting method for examining the electrophoretic properties of urinary Tamm-Horsfall protein. Using this method we tested frozen urine samples from a group of 37 thoroughly investigated recurrent idiopathic renal calcium stone formers and compared this with fresh urine from 19 non-stone forming laboratory staff. We found that there was a statistically significant different pattern of Tamm-Horsfall protein bands in the two sets of urines, with stone formers tending to have two bands and non-stone formers tending to have three bands. This could have been due to storage artefact and therefore a further group of 13 fresh urines from unselected renal stone formers was tested. A smaller proportion of these cases showed the two-band pattern, possibly because not all of this group were idiopathic calcium stone formers. This suggests that but does not prove that there is no significant storage artefact and that there may be an in vivo effect causing stone formation.

Adjuvants, Immunologic↗
PubMed1995

The use of Fourier transform infrared spectrometry for monitoring the retention of polymers in the vitreous humour.

A frequent cause of the failure of various materials tested as artificial vitreous substitutes is their short retention in the vitreous humour of the eye. Previous techniques to monitor the residence time of the vitreous substitutes have been traditionally complicated and usually involved the chemical modification of the test fluids. Fourier transform infrared (FTIR) spectrometry is used in this study to determine the rate of disappearance of a crosslinked poly(1-vinyl-2-pyrrolidinone) (PVP) hydrogel after injection into the vitreous humour of rabbits. The fluid removed from the eye at various postoperative intervals of time (1 day, 1 week, and 1 month) was placed on a horizontal attenuated reflectance (ATR) unit, and the infrared spectrum from 700 to 3000 cm-1 was obtained directly. The absorption band at 1295 cm-1 due to C-N stretching vibration does not overlap with bands of any other species (natural vitreous, blood) present in the test fluid. By estimating the intensity of this band, it was found that about 80% of the injected polymer was removed from the vitreous cavity within 1 month. This study shows that (1) FTIR spectrometry is a convenient method to assess the residence time of foreign materials in the vitreous humour, and (2) the PVP gel is unsuitable in this current form as a permanent vitreous substitute, regardless of the pathways of its removal, such as phagocytosis of fragments produced by the injection process, or enzymatic biodegradation.

Animals↗
PubMed1979

Acute spinal epidural abscess. Observations from fourteen cases.

Fourteen cases of acute spinal epidural abscess are analysed. Postoperatively 6 recovered completely, 4 patients recovered enough to allow unaided walking, 2 died and 2 who were paraplegic pre-operatively remained so. The purpose of this paper is to remind readers of the existence of this condition and to plead for early diagnosis and prompt surgical treatment.

Abscess↗
PubMed1978

The significance for diagnosis and for surgical technique of multiple aneurysms of the same internal carotid artery.

A small series of five patients with more than one aneurysm on the same internal carotid artery is reported. The author believes that similar cases must have been observed by many neurosurgeons but can find no specific reference to the technical and diagnostic problems created by such lesions. Sometimes these lesions can be clipped separately, but when the aneurysms are contiguous it may be helpful to apply a clip with its jaws parallel to the long axis of the internal carotid artery. The author suggests that more case reports would help to advertise the relative frequency of such lesions and thereby should improve their management.

Adult↗
PubMed1976

Treatment of benign intracranial hypertension by dehydrating agents with particular reference to the measurement of the blind spot area as a means of recording improvement.

A series of 30 patients (28 females : 2 males) presenting with benign intracranial hypertension is reported. It is shown that the papilloedema may be resolved in as little as six weeks by the use of dehydration therapy. Evidence is presented that this method can restore to normal a visual acuity which is as low as 6/24 or even 6/36. It is concluded that surgery is never required in the management of this condition. It is strongly recommended that serial blind-spot measurements should be used routinely to assess the effectiveness of therapy. Fluorescein angiography has a place in diagnosis among a small proportion of these patients.

Adolescent↗
PubMed1975

The treatment of thoracic intervertebral disc protrusions.

A series of seventeen patients with a protruded thoracic intervertebral disc is reported. In many cases a trauma, which was sometimes mild, seems to have played a role. This and signs and symptoms (of which pronounced numbness and obtrusive paraesthesiae are the most important) should suggest the diagnosis. In such patients myelography and tomography of the thoracic region is indicated. Twelve of the seventeen patients operated upon improved and nine of them made a good or excellent recovery.

Back Pain↗
PubMed1972

Axial enlargement of the 3rd ventricle, and displacement of the brain-stem in benign aqueduct stenosis.

A personal series of 12 patients with benign aqueduct stenosis has been surveyed. A review of the radiographs has shown that in chronic aqueductal stenosis there is axial enlargement of the 3rd ventricle and displacement of the brain-stem. When these two features are pronounced, blockage of the basal cisterns will occur. We propose that when unsatisfactory flow of fluid through the basal cisterns may be inferred, then ventriculocisternostomy should be avoided. Evidence that the ventricular drainage is continuing satisfactorily after operation may be obtained either by echoencephalography, or by radiography, or by both means.

Adolescent↗
PubMed1971

Diagnosis and treatment of thoracic intervertebral disc protrusions.

A series of 14 patients with a protruded thoracic intervertebral disc is reported. We believe that the true incidence may be as high as one patient per million population per annum. Trauma, sometimes mild, seems to have played a significant role in this series. This fact coupled with pronounced numbness and disagreeable paraesthesiae should suggest the diagnosis with thoracic spinal lesions. Armed with clinical suspicion, radiological verification of the lesion can be expected using a thorough myelographic technique supported if necessary by tomography. A posterolateral approach which combines laminectomy, complete excision of the ligamentum flavum, and the extradural removal of protruded disc is described. The technique is safe and effective.

Adult↗