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H F Parkhouse

Publications and source records attributed to H F Parkhouse.

18 recordsLinked to original sources
PubMed1999

Quantitative 99mTc-DMSA uptake in experimental pyelonephritis.

UNLABELLED: Quantitative 99mTc-dimercaptosuccinic acid (DMSA) renal uptake was studied in unilateral reflux-related pyelonephritis in pigs. The changes to absolute % dose uptake and differential uptake occurring with induction and after treatment of pyelonephritis were correlated with the DMSA images and renal pathology. METHODS: Quantitative uptake in 53 young pigs was obtained from planar images acquired 6 h after injecting the dose. Baseline studies were made (Q1), and studies were made again after urinary infection was established (Q2), when 8 pigs had normal (no defect) renal images (group A), 23 had photon-deficient (reversible) focal defects (group B) and 22 had photon absent (irreversible) focal defects (group C). Q3 studies were made in 21 animals from groups B and C after 3-wk antimicrobial treatment. RESULTS: At Q2 the affected kidney differential uptake was unchanged for group A and reduced for groups B and C (respective mean changes -1.7%, P < 0.01; and -5.5%, P < 0.01). The absolute % dose uptake was unchanged in pyelonephritic kidneys, but increased in the contralateral nondiseased kidneys in groups B and C (respective mean increases +1.4%, P < 0.05; and +5.4%, P < 0.01), while remaining unchanged for group A. In group C, global renal accumulation was actually increased above the Q1 values. After treatment (Q3) the reduced pyelonephritic kidney differential uptake persisted in groups B and C. In group C, however, the increased absolute % dose uptake by the contralateral kidney was less marked and not significantly different from Q1 values in this small group. CONCLUSION: Induction of unilateral pyelonephritis produced a small reduction in diseased kidney differential uptake that was greatest in the group with irreversible imaging defects. The method did not discriminate individuals with reversible and irreversible imaging defects. The decrease in pyelonephritic kidney differential uptake resulted from increased DMSA accumulation (absolute % dose uptake) by the nondiseased contralateral kidney, while that in pyelonephritic kidneys remained unchanged. After treatment, the reduced pyelonephritic kidney differential uptake persisted, but the elevated global DMSA accumulation seen for group C (with irreversible imaging defects) was not sustained and was variable.

Animals↗
PubMed1994

Renal pathology and the 99mTc-DMSA image during the evolution of the early pyelonephritic scar: an experimental study.

This study describes the pathologic changes underlying the appearances of the 99mTc-DMSA renal image during acute pyelonephritis induced in piglets by a combination of vesicoureteral reflux (VUR) and urinary infection. In a total of 42 animals examined, pathologic lesions were identified in 36 of the 46 kidneys subjected to VUR and urinary infection, but no lesions developed in the remaining 10 refluxing kidneys. While scintigraphic defects were invariably associated with pyelonephritic lesions (specificity 100%), some small lesions were not identified (sensitivity 80%). There was a significant association (p = < 0.001) between the degree of photon deficiency seen scintigraphically and the histologic changes (early and late lesions). However, the scintigraphic appearance of individual lesions was also influenced by factors such as their extent and density, so that consideration of the macroscopic characteristics was also important for precise correlation.

Acute Disease↗
PubMed1990

Quantitation of vesico-ureteral reflux by radionuclide cystography and urodynamics.

A method is described for the quantitation of vesico-ureteral reflux by synchronous combined direct radionuclide cystography and urodynamics. Intravesical pressures and volumes are co-ordinated with volumes of reflux. Peak reflux volumes in 11 children diagnosed as having severe (grades 3-4) reflux on conventional contrast cystography ranged from 1 to 50 ml/kidney. A number of different patterns of reflux were observed. Reflux may occur progressively throughout low pressure filling or incrementally with unstable bladder contractions. Reflux during voiding may be maximal as detrusor pressure falls. The method requires wider application to explore the potential for a functional classification of the reflux problem.

Child↗
PubMed1990

Emigration patterns among 1974 British medical graduates.

For 96.7% of identified qualifiers from British medical schools in 1974, career information was available concerning experience outside the United Kingdom. A total of 34.2% of respondents had been abroad at some time by 1987, the peak period being 6 years after qualifying when over 15% were abroad. Twelve per cent were still abroad 13 years after qualifying. Compared to English and Welsh medical schools, Scotish medical schools produced higher percentages of qualifiers who were abroad and who intended not to practise in the United Kingdom. The commonest reasons for going abroad were adventure, travel, vacation, better lifestyle and living conditions, and better career prospects. Further aspects of motivation for travel abroad and return to the United Kingdom are discussed.

Emigration and Immigration↗
PubMed1990

Long-term status of patients with posterior urethral valves.

The short-term prognosis for boys with posterior urethral valves is now very good, but there is growing concern that the long-term prognosis is less favorable. The authors summarize current knowledge about the prospects for renal and bladder function and fertility, which have become urgent considerations with the advent of prenatal diagnosis.

Adult↗
PubMed1989

Renal imaging with 99Tcm-labelled DMSA in the detection of acute pyelonephritis: an experimental study in the pig.

Serial renal 99Tcm-labelled dimercaptosuccinic acid (DMSA) scintigrams were acquired 2-58 days after the introduction of urinary tract infection in 33 pigs with experimentally induced vesicoureteric reflux (VUR). In 29 animals VUR was unilateral and in four bilateral, a total of 37 refluxing systems. Animals were killed either at varying intervals after a scintigraphic defect was noted (24 refluxing kidneys) or after a period when sequential scintigrams were normal (13 refluxing kidneys). The appearance of the scintigram acquired on the day prior to death was compared with the renal pathology, each kidney and renal image being divided into three zones (upper, middle, lower) for separate consideration. Of the 37 refluxing systems pyelonephritic lesions were seen in 27, in a total of 61 zones. In the remaining ten kidneys no scintigraphic defect was detected and no pathological lesions were identified either macroscopically or microscopically. Where an abnormality was detected on the scintigram a lesion was always identified in the kidney (sensitivity 100%). Small pyelonephritic lesions in a total of 12 zones in six kidneys were not detected on the scintigram (specificity 82%). Of the lesions undetected by scintigraphy only one occurred in the upper pole.

Acute Disease↗
PubMed1989

Doctors qualifying from United Kingdom medical schools during the calendar years 1977 and 1983.

At the conclusion of undergraduate medical education in the United Kingdom most students pass a university qualifying examination and obtain a degree in medicine and surgery. Some students pass an external non-university qualifying examination in medicine as an alternative to obtaining a degree, and some do both. The degree may be obtained in the same year as the non-university qualifying examination, or in a different year. Some students from a medical school intake qualify in a later year than expected, for various reasons. Data from university, Health Department and other sources may relate to the academic year, the calendar year, or a fixed date such as 30 September. It is not a simple exercise, therefore, to define the exact number of people who qualify to practise medicine, for the first time, in any given 'year'. In counting qualifiers from individual medical schools, the problems are further compounded by the movement of students between the preclinical and clinical stages of the course, particularly from Oxford and Cambridge to London teaching hospitals. This paper analyses the situation for the calendar years 1977 and 1983, showing a decline in the number of students obtaining double (i.e. both university and non-university) qualifications. The number of UK graduates not registering with the General Medical Council to practise, at least for a time, in the UK was small, and the population base compiled for Medical Career Research Group studies was reasonably accurate in each of the 2 years examined.

Humans↗
PubMed1989

The value of urethral sphincter electromyography in the differential diagnosis of parkinsonism.

A series of 54 patients presenting with parkinsonism underwent clinical assessment and urethral sphincter electromyography (EMG). After clinical assessment, 26 were thought to be suffering from probable multiple system atrophy (MSA), 15 were thought to have possible MSA and 13 were diagnosed as having probable idiopathic Parkinson's disease (IPD). Of those with probable MSA, 16 were found to have an abnormal urethral sphincter EMG. In the group with possible MSA, only 5 patients had an abnormal EMG while in the group with probable IPD, only 1 patient had an abnormal EMG. It was concluded that urethral sphincter electromyography provides a useful method of distinguishing between idiopathic Parkinson's disease and multiple system atrophy. It also provides a means of identifying those patients with parkinsonism whose incontinence may well be worsened, or in whom incontinence may develop following lower urinary tract surgery.

Aged↗
PubMed1988

Abnormal electromyographic activity of the urethral sphincter, voiding dysfunction, and polycystic ovaries: a new syndrome?

A potential association between abnormal electromyographic activity--that is, decelerating bursts and complex repetitive discharges--of the urethral sphincter and difficulty in voiding was examined in 57 women with urinary retention. Abnormal electromyographic activity was found in 33. Ultrasonography of the ovaries in 22 of the 33 women showed that 14 had polycystic ovaries. Of the other eight women, two had had oophorectomies, one had shrunken ovaries and ovarian failure, and one had previously undergone oophorectomy and the other ovary could not be seen; in one neither ovary could be seen, and three had ovaries of normal appearance, although two of these women were taking the contraceptive pill. Thirteen of the group had endocrine symptoms and signs characteristic of the polycystic ovary syndrome. Videocystometrography in 17 of the women who were examined by ultrasonography showed low flow rates and high residual volumes of urine after micturition in 12 women who could void, the other five having chronic urinary retention. A speculative hypothesis for the observed association of impaired voiding, abnormal electromyographic activity of the urinary sphincter, and polycystic ovaries is advanced, based on the relative progesterone deficiency that characterises the polycystic ovary syndrome. Progesterone stabilises membranes, and its depletion might permit ephaptic transmission of impulses between muscle fibres in the muscle of the urethral sphincter, giving rise to the abnormal electromyographic activity. This may impair relaxation of the sphincter, resulting in low flow rates of urine, incomplete emptying of the bladder, and, finally, urinary retention.

Adult↗
PubMed1988

Investigation of the dilated urinary tract.

Dilatation of the urinary tract does not necessarily imply obstruction, and other factors may be operative: maldevelopment, infection, reflux, and polyuria. Obstruction of the urinary tract in intra-uterine life is associated with renal dysplasia: the original obstructive lesion may be transient but the consequent dysplasia and dilatation may be permanent. Routine antenatal ultrasound identifies a new population of infants with urinary tract dilatation, many of whom remain asymptomatic and would not otherwise have come to medical attention: the natural history and appropriate schedules of investigation and management of this group are still being evaluated. Anatomical imaging by ultrasound establishes the presence and extent of dilatation. Micturating cystourethrography, intravenous urography and antegrade pyelography establish the site but not the functional significance of an obstructive lesion. Isotope renal scanning with 99mTc-DTPA may identify an acutely obstructed kidney with a decrease renal uptake, prolonged parenchymal transit time, and delayed clearance of the isotope from the renal pelvis after furosemide. However, such analyses often give equivocal results in infants with poor renal function and markedly dilated urinary tracts. Obstructive uropathy should be seen as a disturbance of the normal pressure-flow relationships in the urinary tract, and be defined and investigated as such. Antegrade perfusion with renal pelvic pressure measurements has technical pitfalls, but is the definitive method of establishing upper tract obstruction. Videocystourethrography is the established method of investigating the lower urinary tract in older children but needs further development to be applicable to infants.

Child↗
PubMed1988

Long-term outcome of boys with posterior urethral valves.

One hundred and fourteen boys with posterior urethral valves were treated between 1966 and 1975. Four died during the first hospital admission, 6 died from renal failure during childhood, 1 died from other causes and 15 were lost to follow-up. Eighty-eight were reviewed 11 to 22 years after diagnosis and the renal outcome of 98 patients is therefore known. Approximately one-third of patients presented under 1 month of age, between 1 month and 1 year, and over 1 year respectively. Bilateral vesicoureteric reflux was observed in one-quarter of the boys, more frequently in those presenting in the first month of life. Half of the patients were treated by primary valve ablation and half underwent temporary upper tract diversion: the outcome was worse for the diverted group. One-third of the boys had a long-term bad outcome for renal function. This outcome was associated with early presentation, bilateral vesicoureteric reflux and day-time urinary incontinence after the age of 5 years. The association of bad outcome with incontinence points to continuing bladder dysfunction as a major determinant of long-term outcome for renal function.

Follow-Up Studies↗
PubMed1987

Quantitative study of phenol as a neurolytic agent in the urinary bladder.

The endoscopic subtrigonal injection of a 6% aqueous phenol solution is an effective technique for denervating the bladder but its clinical usefulness is limited by unpredictable side effects. This study explored the possibility of making this procedure safer by comparing the neurolytic effects of different concentrations and carriers of phenol. Phenol in 2.5 and 5% solutions in three different carriers (water, glycerine and oil) was injected into the rectovesical pouch in 35 rats. After 3 weeks the bladders were excised and the effects on the density of acetylcholinesterase-positive nerves were assessed in each animal using morphometric techniques. The density of enzyme-containing nerves was reduced by 20% in the phenolised animals when compared with controls. This reduction was maximum when water was used as the carrier for either 2.5 or 5% phenol solutions.

Administration, Intravesical↗