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Biomedical subjects

R H Whitaker

Publications and source records attributed to R H Whitaker.

At least 91 records · Page 5Linked to original sources
PubMed1979

Ureters that show both reflux and obstruction.

Eight ureters in 6 male patients have been shown radiographically and dynamically to exhibit both reflux and obstruction. The greater the degree of obstruction the more dilated the upper urinary tract. Reflux may be considerable, but in severely obstructed ureters it may be minimal. Both urologists and radiologists should be aware of this unusual association. When it occurs patients should not be managed conservatively, but should have their ureters reimplanted.

Adult↗
PubMed1979

The Whitaker test.

Since obstruction can be satisfactorily defined only in dynamic terms, it is not surprising that in a difficult case, a dynamic means of investigation is needed. The dynamic approach described in detail has been proved to be of great value in a variety of clinical situations. Further, both the apparatus and the technique are well within the scope of any urologist with access to radiologic equipment.

Humans↗
PubMed1977

Pressure-controlled nephrostography.

Nephrostomy tubes are often left in the kidney after renal operations. Radiographic studies with contrast medium via the tube post-operatively give anatomical information but little or sometimes even misleading information concerning the dynamics of the upper urinary tract. A pressure/flow-controlled nephrostogram allows not only the passage of medium to be watched but the significance of any hold-up or narrowing to be assessed in dynamic terms. In this way small degrees of obstruction can be identified. There are many situations in which this information is of considerable clinical value.

Female↗
PubMed1977

Hydronephrosis.

It is essential to distinguish between an obstructed and an unobstructed hydronephrosis as the management of the two types is quite different. Some of the radiographic and isotopic methods of distinguishing these two leave much to be desired and the place of dynamic studies is discussed. The aetiology of pelviureteric junction obstruction remains uncertain, but it is probable that one or more of several factors may be involved and these are discussed. The types of hydroenphrosis are classified as chronic, intermittent, unsuspected, equivocal, and reflux-induced.

Adolescent↗
PubMed1976

Investigating wide ureters with ureteral pressure flow studies.

A perfusion study is described and its usefulness in the diagnosis of ureterovesical obstruction is discussed. The study includes 31 children with either primary or secondary non-refluxing wide ureters or ureters that had been reimplanted previously.

Child↗
PubMed1976

Primary pelvic hydronephrosis in children: a retrospective survey.

A retrospective review of 63 children with primary pelvic hydronephrosis has revealed many features similar to those in adults. A plea is made for the greater use of pressure/flow studies in the renal pelvis in the assessment of hydronephrosis. The value of a modified and simplified nephroplasty as an adjunct to pyeloplasty in the more advanced obstructive cases is described and its greater use encouraged.

Adolescent↗
PubMed1976

Reflux induced pelvi-ureteric obstruction.

The phenomenon of pelvi-ureteric obstruction which is induced by vesico-ureteric reflux is well documented but ill understood. The radiographic findings can be impressive to an extent that obstruction is probably often over-diagnosed. Before considering a pyeloplasty it is essential to confirm the true obstructive nature of the problem. Where the urogram is not suggestive of an obstruction a re-implantation of the ureter will usually stop the gross pelvic dilatation. It is suggested that the obstruction is at least partially an active process.

Humans↗
PubMed1975

Ureteral pressure flow studies in difficult diagnostic problems.

Before a ureteral operation is undertaken for dilated, non-refluxing ureters it is essential to determine whether obstruction is present, since an operation is unnecessary and can be hazardous if there is no obstruction or infection. Obstruction is most accurately diagnosed by perfusing the upper tract at a known flow rate and measuring the resulting pressure. This test was performed on 5 patients in whom there was doubt as to the presence of obstruction from the radiographic evidence. In 4 of the 5 patients low pressure was found, the obstruction was excluded and an operation was avoided. In the fifth patient the obstruction was confirmed and relieved. The pressure flow test is useful in the diagnosis or exclusion of obstruction in the upper urinary tract.

Adult↗
PubMed1975

The effect of steroid hormones on the growth pattern and RNA synthesis in human benign prostatic hyperplasia in organ culture.

The effect of testosterone, dihydrotestosterone, 3 beta-androstanediol and oestradiol-17 beta on the morphology and RNA synthesis in human benign prostatic hyperplasia (BPH) in organ culture has been investigated. In hormone treated and untreated explants alike, the epithelium multiplied to form several layers. This effect was most marked after exposure to dihydrotestosterone. In explants grown in non-supplemented medium the epithelium showed some squamous changes; testosterone or dihydrotestosterone preserved the secretory character of the epithelium while oestradiol-17 beta caused cellular degeneration. The incorporation of 3H-uridine into RNA was studied by autoradiography. In the epithelium, testosterone or dihydrotestosterone raised the uptake significantly over that measured in the control explants, oestradiol-17 beta reduced it while 3 beta-androstanediol produced similar values to those found in the control explants. The incorporation of 3H-uridine in the smooth muscle cells was increased by testosterone and decreased by oestradiol-17 beta. A comparison with normal rat prostatic epithelium in organ culture showed that in the absence of androgens the incorporation of 3H-uridine was lower than in BPH and the effect of testosterone correspondingly greater. The results suggest that although the growth of human BPH in organ culture appears to be androgen dependent, it still remains hormone sensitive and can be influenced by steroid hormones in a similar manner to that in rat prostatic gland. They further show that the smooth muscle of the stroma is also hormone sensitive, a point which should be considered in the hormonal management of benign prostatic hyperplasia.

Aged↗
PubMed1975

Some observations and theories on the wide ureter and hydronephrosis.

A simple but effective classification of the wide ureter is proposed. It separates ureters into two major groups of refluxing and non-refluxing, but emphasises that not all non-refluxing ureters are obstructed. An analysis is made of normal and abnormal ureteric peristalsis and the part it plays in conducting a bolus through the pelviureteric and ureterovesical junctions. A theory is advanced to explain the poor emptying of the wide ureter and the abnormal pelviureteric junction. It is based on the inability of the circular and longitudinal muscles to form a bolus and it explains how the unopposed and inadvertent contraction of the circular muscle grips the orifice in each situation to aggravate the poor emptying.

Glomerular Filtration Rate↗
PubMed1975

Equivocal pelvi-ureteric obstruction.

A series of 40 studies have been used to assess whether or not there is obstruction in the pelvi-ureteric region in 27 kidneys. The perfusion test which is discussed has provided an answer in all cases where the technique was possible and allowed a logical decision to be taken concerning management.

Adult↗
PubMed1975

A simple classification of wide ureters.

A simple classification of abnormal ureters is presented which categorises the ureters according to the presence or absence of 3 factors, namely reflux, bladder outlet obstruction and ureteric obstruction. It has been devised to try to rid the literature of many confusing and obsolete terms and it is hoped that this new classification may become internationally accepted.

Humans↗
PubMed1973

Urethral valves.

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Adolescent↗