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Biomedical subjects

M A Thomas

Publications and source records attributed to M A Thomas.

At least 127 records · Page 7Linked to original sources
PubMed1987

Familial IgA nephropathy: a study of renal disease in an Australian aboriginal family.

An Australian Aboriginal family, extending four generations, with a high incidence of renal disease was investigated. Twenty-eight of 114 members screened had hematuria. Of those tested, five had hypertension, four maturity onset diabetes, one a raised serum creatinine concentration, five elevated serum IgA levels and two cortical scarring on intravenous pyelogram. Of the eight members who underwent renal biopsy, five had IgA nephropathy and one had light and electron microscopy evidence of glomerulonephritis, but no IgA was seen on immunofluorescence. One had mild nonspecific changes by light microscopy but no immunofluorescence or electron microscopy was available and the remaining patient had mild changes consistent with hypertension and diabetes. HLA typing, carried out for 27 family members, showed an increased incidence of HLA-B22, B27, B39, and DR1 when compared to Yuendumu Aborigines (B27 and DR1), or Australian Caucasians (B22), or both (B39). This may be due to an association with IgA nephropathy, or a family clustering of antigens. Overall, this study suggests a genetic mechanism in the pathogenesis of IgA nephropathy in some patients and, as there was evidence of renal disease in 25% of those tested, may indicate an underlying high incidence of renal disease in the Aboriginal community.

Adolescent↗
PubMed1987

Radial nerve damage as a complication of elbow arthroscopy.

Posterior interosseous nerve damage following elbow arthroscopy occurred in a 20-year-old athlete. The course of the radial nerve brings it in proximity to the puncture site when the dorsoradial approach is selected. This case emphasizes the importance of careful attention to vital structures if the complication of a posterior interosseous nerve syndrome is to be avoided.

Adult↗
PubMed1986

Rebleeding after traumatic hyphema.

We reviewed the medical records of 175 patients who were admitted between 1977 and 1984 with a diagnosis of traumatic hyphema to define the incidence of operative intervention for the treatment of complications related to rebleeding. Of the 156 patients admitted with primary hyphemas, 25 (16%) rebled during hospitalization. Seven of these 25 in-hospital rebleeds required surgical intervention. Nineteen other patients were admitted with ocular histories and examinations strongly suggestive of rebleeding prior to admission (secondary hyphema--presumed preadmission rebleed). Seven of these 19 eyes underwent surgery. Of the 175 eyes studied, only one eye that did not rebleed underwent surgery during the initial hospitalization. Fourteen (32%) of 44 eyes that rebled underwent operative intervention. Nine of these 14 patients were operated on under general anesthesia. Potential benefits of newer hyphema treatments, such as epsilon-aminocaproic acid, designed to prevent rebleeding should be weighed against not only the ocular risks of rebleeding but also the risks of general anesthesia.

Adolescent↗
PubMed1986

Management of postoperative suprachoroidal hemorrhage with continuous-infusion air pump.

Seven patients suffered delayed nonexpulsive suprachoroidal hemorrhages following filtration procedures. Six of seven eyes were aphakic, while the seventh had a subluxated lens associated with aniridia. In six of the seven cases, the hemorrhagic choroidal detachments completely filled the posterior segment, and visual acuity was reduced to light perception only. Surgical drainage of the hemorrhages was accomplished through one or two sclerotomies with simultaneous air insufflation of the eye through a limbal needle attached to a continuous-infusion air pump. With this technique, visual acuity was restored to a level equal to or better than the prefiltration acuity in five of seven patients. One patient suffered a slight decline in acuity from 20/60 to 20/100, and another patient's visual acuity declined from finger counting at 5 cm to hand motions.

Adult↗
PubMed1986

Idiopathic recurrent branch retinal arterial occlusion.

Recurrent multiple branch retinal arterial occlusions of unknown cause occurred in nine apparently healthy individuals. With the exception of three patients who developed associated auditory symptoms, none developed other signs or symptoms of systemic vascular disease. Ophthalmoscopic and fluorescein angiographic findings suggested focal arteritis and arteriolitis as the cause of the obstructions. Most patients retained good visual acuity.

Adult↗
PubMed1986

Pulse radiolysis study of a yeast cytochrome c from Hansenula anomala.

The reduction of Hansenula anomala yeast cytochrome c by e-aq and CO-.2 was investigated by pulse radiolysis, at a high reductant to protein concentration ratio. The reactivity of the radicals was studied by observing absorbance changes in the cytochrome c spectrum over the wavelength range 280-600 nm. At pH 7, over the time scale of the radical decays (i.e. 0-4 microseconds for e-aq; 0-40 microseconds for CO-.2s) and beyond, the hemoprotein was reduced without any spectrally detected intermediate between ferri-and ferro-forms. This conclusion was reached by simulation studies based on the direct reduction of the yeast cytochrome c from the ferri- to the ferro-form, yielding a correct fit between experimental and calculated absorbance curves. The reduction rate constants were determined to be 1.0 +/- 01 X 10(10) M-1 S-1 for e-aq and 0.7 +/- 0.05 X 10(9) M-1 S-1 for CO-.2 at 0.16 M ionic strength, pH 7.0 and 20 degrees C, thus not significantly different from other values reported for horse heart cytochrome c. However, in the 360-390 nm region the generation of an additional radical species was noticed. The present experimental data were compared with previously published reports.

Carbon Dioxide↗
PubMed1985

Renal autotransplantation for severe loin-pain/haematuria syndrome.

Most forms of therapy for the loin-pain/haematuria syndrome are unsuccessful, though nerve-block procedures and renal denervation sometimes provide temporary relief. Three young patients, with pain so severe that they were dependent on narcotics, were treated for this syndrome. All three had been repeatedly admitted to hospital. Loin pain was unilateral in two patients and predominantly so in the third. Renal function, excretion urography, and angiography were normal, but renal biopsy specimens showed deposition of the third component of complement in the renal arterioles. All were treated with renal autotransplantation; the kidney causing pain (or the one causing the most pain) was completely excised and reimplanted in the iliac fossa. Two patients had complete relief of pain and the third almost complete relief, despite recurrence of haematuria in all three. It is too early to determine whether this major procedure is justified in the treatment of the loin-pain/haematuria syndrome, but the early results are encouraging.

Adolescent↗
PubMed1985

Prostaglandin levels in human vitreous.

Vitreous samples were obtained from 41 eyes undergoing vitrectomy, and radioimmunoassays were performed to measure concentrations of the prostaglandins PGE2, PGF2 alpha, prostacyclin, and thromboxane. Presumably physiological levels (approximately 100 picograms/ml) were found in vitreous from eyes undergoing cataract extraction. Eyes with vitreous haemorrhage, retinal detachment, or cystoid macular oedema had similarly low levels. Vitreous prostaglandins were mildly elevated in trauma and endophthalmitis and markedly elevated in aphakic bullous keratopathy. The role prostaglandins may play in cystoid macular oedema is reviewed.

Adult↗
PubMed1985

Rhabdomyolysis and acute renal failure.

In order to determine the prevalence of rhabdomyolysis-associated acute renal failure (RM-ARF) and assess the effect of oliguria on biochemical features in this condition, 127 cases of ARF seen over 18 months were reviewed. Eleven cases of RM-ARF were seen, a prevalence of 8.6% of all cases of ARF. There were ten males and one female (age range 15-72 years) with precipitating events being trauma in three, coma in two, infection in two and other causes in five. Ten had concurrent clinical or historical evidence of dehydration, two had mild hypokalemia, and one abused alcohol. Serum and urine myoglobin by radioimmunoassay were greater than 800 ng/l in all cases tested. False negative tests for urine myoglobin by o-tolidine reaction after (NH4)2SO4 extraction occurred in four cases. Despite attempted forced saline diuresis and urinary alkalinisation, seven became oliguric and required dialysis for 12-81 days. Initially (pre-dialysis) oliguric patients had significantly higher maximum serum levels of potassium, phosphate, and rate of rise of creatinine, significantly lower trough levels of calcium, and no significant difference in peak creatine phosphokinase or uric acid levels than non-oliguric patients. Two subjects developed recovery phase hypercalcemia, four required fasciotomy for compartment syndromes, three sustained permanent nerve damage, and three required limb amputation. Ten survived, with a mean creatinine clearance of 96 ml/min after nine to 30 months. RM-ARF is common, may be clinically occult and show false negative urine myoglobin tests. Hyperkalemia, hyperphosphatemia, and hypocalcemia are more common in oliguric than in non-oliguric RM-ARF, but both have a good prognosis with appropriate medical and surgical management.

Acute Kidney Injury↗
PubMed1985

The development of infant sensitivity to biomechanical motions.

3 experiments were conducted to examine infant sensitivity at 20, 30, and 36 weeks of age to the 3-dimensional structure of a human form specified through biomechanical motions. All 3 experiments manipulated occlusion information in computer-generated arrays of point-lights moving as if attached to the major joints and head of a person walking. These displays are readily recognized as persons by adults when occlusion information is present, but not when it is absent or inconsistent with the implicit structure of the human body. Converging findings from Experiments 1 and 2 suggested that 36-week-old infants were sensitive to the presence of occlusion information in point-light walker displays; neither 20- nor 30-week-old infants showed any sensitivity to this information. The results of Experiment 3 revealed further that 36-week-old infants were sensitive to whether or not the pattern of occlusion was consistent with the implicit form of the human body, but only when the displays were presented in an upright orientation. These findings are interpreted as suggesting that infants, by 36 weeks of age, are extracting fundamental properties necessary for interpreting a point-light display as a person.

Biomechanical Phenomena↗
PubMed1984

Treatment technique for chronic wrist cutters.

A treatment technique is presented which has been developed to eliminate chronic self-induced wrist cutting behavior. The technique substitutes painful but non-injurious exercises for self-cutting behavior when the urge to self-cut emerges. The rationale for initiating this approach is described.

Adult↗
PubMed1984

Specificity of ultrasonography in the diagnosis of benign breast masses.

Ultrasound has become increasingly important in the management of benign breast disease. The main reasons are its ability to distinguish between cystic and solid lesions, its special advantages in examining the dense breast, and the absence of potential radiation hazard. This paper evaluates the specificity of automated ultrasound in the diagnosis of benign lesions. The usefulness of the signs established for the diagnosis of benign masses is analyzed. Atypical lesions are discussed and the role of ultrasonography in the differential diagnosis of benign lesions is reviewed.

Abscess↗
PubMed1984

The perioperative management of the patient with pemphigus vulgaris and villous adenoma.

A focal adenocarcinoma in a rectal villous adenoma occurred in a patient with pemphigus vulgaris. The dermatologic, surgical, and anesthetic aspects of the patient's management required special consideration. A gastrostomy was performed and the rectal carcinoma was removed surgically by low anterior colon resection with end-to-end anastomosis. Because of the patient's pemphigus lesions, epidural anesthesia augmented by intravenous ketamine was administered to avoid airway instrumentation. Supplemental oxygen during surgery was delivered by nasal cannula. Therapy with oral prednisone was begun two weeks postoperatively.

Adenocarcinoma↗