What is the evidence for interactions between filaggrin null mutations and environmental exposures in the aetiology of atopic dermatitis? A systematic review

BACKGROUND

Epidemiological studies indicate that gene-environment interactions play a role in atopic dermatitis (AD).

OBJECTIVES

To review the evidence for gene-environment interactions in AD aetiology, focusing on filaggrin (FLG) loss-of-function mutations.

METHODS

A systematic search from inception to September 2018 in Embase, MEDLINE and BIOSIS was performed. Search terms included all synonyms for AD and filaggrin/FLG; any genetic or epidemiological study design using any statistical methods were included. Quality assessment using criteria modified from guidance (ROBINS-I and Human Genome Epidemiology Network) for nonrandomized and genetic studies was completed, including consideration of power. Heterogeneity of study design and analyses precluded the use of meta-analysis.

RESULTS

Of 1817 papers identified, 12 studies fulfilled the inclusion criteria required and performed formal interaction testing. There was some evidence for FLG-environment interactions in six of the studies (P-value for interaction ≤ 0·05), including early-life cat ownership, older siblings, water hardness, phthalate exposure, higher urinary phthalate metabolite levels (which all increased AD risk additional to FLG null genotype) and prolonged breastfeeding (which decreased AD risk in the context of FLG null genotype). Major limitations of published studies were the low numbers of individuals (ranging from five to 94) with AD and FLG loss-of-function mutations and exposure to specific environmental factors, and variation in exposure definitions.

CONCLUSIONS

Evidence on FLG-environment interactions in AD aetiology is limited. However, many of the studies lacked large enough sample sizes to assess these interactions fully. Further research is needed with larger sample sizes and clearly defined exposure assessment. Linked Comment: Park and Seo. Br J Dermatol 2020; 183:411.

Ethnic differences in the severity and clinical management of type 2 diabetes at time of diagnosis: A cohort study in the UK Clinical Practice Research Datalink

AIMS

To characterize ethnic differences in the severity and clinical management of type 2 diabetes at initial diagnosis.

METHODS

An observational cohort study of 179,886 people with incident type 2 diabetes between 2004 and 2017 in the Clinical Practice Research Datalink was undertaken; 63.4% of the cohort were of white ethnicity, 3.9% south Asian, and 1.6% black. Ethnic differences in clinical profile at diagnosis, consultation rates, and risk factor recording were derived from linear and logistic regression. Cox-proportional hazards regression was used to determine ethnic differences in time to initiation of therapeutic and non-therapeutic management following diagnosis. All analyses adjusted for age, sex, deprivation, and clustering by practice.

RESULTS

In the 12 months prior to diagnosis, non-white groups had fewer consultations compared to white groups, but risk factor recording was better than or equivalent to white groups for 9/10 risk factors for south Asian groups and 8/10 risk factors for black groups (p < 0.002). Blood pressure, BMI, cholesterol, eGFR, and CVD risk levels were more favourable in non-white groups, and prevalence of macrovascular disease was significantly lower (p < 0.003). Time to initiation of antidiabetic treatment and first risk assessment was faster in non-white groups relative to white groups, while time to risk factor measurement and diabetes review was slower.

CONCLUSIONS

We find limited evidence of systematic ethnic inequalities around the time of type 2 diabetes diagnosis. Ethnic disparities in downstream consequences may relate to genetic risk factors, or manifest later in the care pathway, potentially in relation to long-term risk factor control.

Ethnic differences in urinary calcium and phosphate excretion between Gambian and British older adults

Ethnic differences in renal calcium and phosphate excretion exist, which may depend on differences in their dietary intakes and regulatory factors. We report highly significant differences in urinary calcium and phosphate excretion between white British and Gambian adults after statistical adjustment for mineral intakes, indicating an independent effect of ethnicity.

INTRODUCTION

Populations vary in their risk of age-related osteoporosis. There are racial or ethnic differences in the metabolism of the bone-forming minerals calcium (Ca) and phosphate (P), with a lower renal Ca and P excretion in African-Americans compared to white counterparts, even at similar intakes and rates of absorption. Also, Africans in The Gambia have a lower Ca excretion compared to white British subjects, groups known to differ in their dietary Ca intake. Here, we report on differences in urinary Ca and P excretion between Gambian and white British adults while allowing for known predictors, including dietary intakes.

METHODS

Participants were healthy white British (n = 60) and Gambian (n = 61) men and women aged 60-75 years. Fasting blood and 2-h urine samples were collected. Markers of Ca and P metabolism were analysed. Dietary intake was assessed with country-specific methods.

RESULTS

White British older adults had higher creatinine-corrected urinary Ca and P excretion (uCa/uCr, uP/uCr) and lower tubular maximum of Ca and P compared to Gambian counterparts. The predictors of urinary Ca and P differed between groups. Multiple regression analysis showed that dietary Ca and Ca/P were predictors of uCa/uCr and uP/uCr, respectively. Ethnicity remained a significant predictor of uCa/uCr and uP/uCr after adjustment for diet and other factors.

CONCLUSIONS

Gambian older adults have higher renal Ca conservation than British counterparts. Dietary mineral intakes were predictors of the differences in urinary Ca and P excretion, but ethnicity remained a highly significant predictor after statistical adjustment. This suggests that ethnicity has an independent effect on renal Ca and P handling.

Surveillance of Patients with Metal-on-Metal Hip Resurfacing and Total Hip Prostheses: A Prospective Cohort Study to Investigate the Relationship Between Blood Metal Ion Levels and Implant Failure

BACKGROUND

We designed a prospective, single-center study to assess whether blood metal ion levels could predict implant failure in patients managed with unilateral metal-on-metal hip resurfacing or total hip arthroplasty.

METHODS

Five hundred and ninety-seven patients who had received unilateral Articular Surface Replacement prostheses at least twelve months earlier were recruited. Blood metal ion levels were compared between the group of patients with failed implants and the group with non-failed implants. Implant failure was defined as prostheses associated with revision, an intention to revise, or poor patient-reported hip function (Oxford Hip Score, <31 of 48). Specificity, sensitivity, area under the curve, positive and negative predictive values, and odds ratios were calculated. Logistic regression analysis was used to identify other risk factors for implant failure.

RESULTS

Patients with failed arthroplasty had significantly higher blood cobalt and chromium ion levels than did patients with non-failed arthroplasty (p < 0.01). Blood cobalt ion levels were disproportionately raised in patients with failed total hip arthroplasty (8.2 μg/L) compared with patients with failed hip resurfacing (2.5 μg/L) (p = 0.018). Blood chromium ion levels were not significantly different in patients with failed total hip arthroplasty and failed hip resurfacing (p = 0.058). The maximum value of either metal ion had good discriminant ability to predict implant failure (area under the curve, 0.76). A 7-μg/L cutoff had a positive predictive value of 0.75 (95% confidence interval, 0.66 to 0.82) and a negative predictive value of 0.82 (95% confidence interval, 0.78 to 0.86). In patients managed with total hip arthroplasty, for each increase of 1 μg/L there was a 23% (p < 0.001) increase in the odds of them being in the failed group. For patients managed with hip resurfacing, the increase in odds was 5% (p < 0.001).

CONCLUSIONS

Raised levels of blood metal ions were associated with failed metal-on-metal hip resurfacings and total hip arthroplasties. A threshold level of 7 μg/L had inadequate sensitivity to be used in isolation as a screening test for implant failure, but it provided nearly optimal misclassification rates. No level had a perfect positive predictive value, and so we discourage surgeons from performing revision surgery based on blood metal ion levels alone. Levels of cobalt ions were raised out of proportion to levels of chromium ions in failed total hip arthroplasty and may reflect a different mechanism for metal ion generation.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Design and cohort description of the InterAct Project: an examination of the interaction of genetic and lifestyle factors on the incidence of type 2 diabetes in the EPIC Study

AIMS/HYPOTHESIS

Studying gene-lifestyle interaction may help to identify lifestyle factors that modify genetic susceptibility and uncover genetic loci exerting important subgroup effects. Adequately powered studies with prospective, unbiased, standardised assessment of key behavioural factors for gene-lifestyle studies are lacking. This case-cohort study aims to investigate how genetic and potentially modifiable lifestyle and behavioural factors, particularly diet and physical activity, interact in their influence on the risk of developing type 2 diabetes.

METHODS

Incident cases of type 2 diabetes occurring in European Prospective Investigation into Cancer and Nutrition (EPIC) cohorts between 1991 and 2007 from eight of the ten EPIC countries were ascertained and verified. Prentice-weighted Cox regression and random-effects meta-analyses were used to investigate differences in diabetes incidence by age and sex.

RESULTS

A total of 12,403 verified incident cases of type 2 diabetes occurred during 3.99 million person-years of follow-up of 340,234 EPIC participants eligible for InterAct. We defined a centre-stratified subcohort of 16,154 individuals for comparative analyses. Individuals with incident diabetes who were randomly selected into the subcohort (n = 778) were included as cases in the analyses. All prevalent diabetes cases were excluded from the study. InterAct cases were followed-up for an average of 6.9 years; 49.7% were men. Mean baseline age and age at diagnosis were 55.6 and 62.5 years, mean BMI and waist circumference values were 29.4 kg/m(2) and 102.7 cm in men, and 30.1 kg/m(2) and 92.8 cm in women, respectively. Risk of type 2 diabetes increased linearly with age, with an overall HR of 1.56 (95% CI 1.48-1.64) for a 10 year age difference, adjusted for sex. A male excess in the risk of incident diabetes was consistently observed across all countries, with a pooled HR of 1.51 (95% CI 1.39-1.64), adjusted for age.

CONCLUSIONS/INTERPRETATION

InterAct is a large, well-powered, prospective study that will inform our understanding of the interplay between genes and lifestyle factors on the risk of type 2 diabetes development.

Treatment of stable vitiligo hands by ReCell system: a preliminary report

BACKGROUND

The aim of this report was to analyze the results obtained with the ReCell system for the surgical treatment of stable vitiligo hands.

MATERIALS AND METHODS

One patient with stable vitiligo of the hands was admitted at the Department of Plastic and Reconstructive Surgery, University of Rome Tor Vergata. The patient underwent to ReCell system for the treatment of stable vitiligo hands.

RESULTS

The repigmentation was assessed using the Vitiligo Area Scoring index (VASI). The extent of pigmentation was scored as excellent, good, fair, and poor depending on the percentage of the repigmentation in the previously depigmented site. The color of the repigmented area was compared with the adjacent normally pigmented area. The patient had an excellent repigmentation.

CONCLUSIONS

ReCell system is a simple, safe and feasible technique. The method that uses noncultured autologous epidermal suspension is simpler, cheaper, less time consuming and does not require sophisticated laboratory facilities, when compared with methods employing cultured melanocytes.

Compartment syndrome of the hand with acute bullous eruption due to extravasation of computed tomography contrast material

This article presents a case of an 80-year-old woman with severe hematoma and consequently a compartmental syndrome of the hand complicated with acute bullous eruption due to extravasation of contrast material. Compartment syndrome of the hand has been linked to a number of various etiologies. Failure to adequately diagnose and treat compartment syndromes of the hand can lead to irreparable functional loss. In the majority of the cases extravasation results only in minimal swelling or erythema. However, severe skin necrosis, ulceration and compartment syndrome may occur with extravasation of large volumes. Compartment syndrome was diagnosed, and the patient underwent immediately fasciotomy. After fasciotomy we weekly followed up our patient with medications and after she regained the full use of the hand. We report this case to assess the importance of a careful evaluation of the intravenous administration site and close monitoring of the patient during contrast material injection to obtain minimal or prevent every kind of extravasation injuries.

New trends in breast reconstructive surgery: "Florentine Lily" reductive mastoplasty

BACKGROUND

To describe a mammoplasty technique that we called "Florentine Lily" because of the shape of the pre-operative drawings similarity with the symbol lily Florentine.

METHODS

In a group of 190 women who underwent reductive mammoplasty, 23 women affected by severe enlarged breasts were selected. Main selection requirements were: 18-30 cm rising of the Areola-Nipple Complex (NAC).

RESULTS

to obtain a functional and cosmetic result; preservation of mammary gland function; vitality of the areola-nipple complex and its sensitivity. We describe the case of 35 years old woman affected by severe enlargement of the breast and no pathologies.

CONCLUSION

We didn't observe necrosis of the skin flaps and NAC in any case. In one case (rising of Nipple-Areola Complex >25 cm) NAC showed NAC 2 days post-surgery, which spontaneously resolved. Minor complications (edema and ematoma) developed in 20 cases. No infections were observed.

A case of labial fusion and urinary pseudo-incontinence in an elderly woman. A surgical treatment and a review

Labial fusion is defined as either partial or complete adherence of the labia minora (1), and also called vulvar fusion, adhesions of the labia minor or conglutination of the labia minora and sinechia of the vulva. The complete and severe labial fusion is a rare pathology with a small number of cases reported in the literature in adults. We present a case report of a postmenopausal woman who presented with voiding difficulty and incontinence and was treated by surgical division of the adhesions and immediate resolution of the urinary incontinence confirmed by multichannel urodynamic test postoperatively.

A neglected giant subcutaneous leiomyosarcoma of the shoulder: a case report

Superficial leiomyosarcoma is an exceeding uncommon malignant tumor, which can be located either cutaneous or subcutaneous tissues. It may occur anywhere in the body, but there is a predilection for the thighs. The distinction between cutaneous or subcutaneous, increased mass size (> 5 cm) and depth are considered to have worst prognosis in terms of recurrence and metastasis. We report a rare case of an 81-year-old woman, presented with a 20-cm leiomyosarcoma of the shoulder. The patient reported that the mass was completely asymptomatic and its growth was slow. A CT study showed a lesion closely apposed to the head of the humerus and revealed no a clear relationship with the surrounding muscles. There was no regional lymphadenopathy or the evidence of metastatic disease. After tumor resection, a large skin and soft-tissue defect was remained and the repair was performed by myocutaneous rotational free flap of latissimus dorsi. The conclusion of the histological analysis was: subcutaneous leiomyosarcoma pT2--grade 1+ (NCI system). The delayed diagnosis and the surgical treatment and giant size of soft tissue leiomyosarcoma may adversely affect the final result.

Description of columellar defects and its tridimensional remedial techniques

Columella is an important facial component and provides support and projection to the tip of the nose. Columella defects may cause significant aesthetic and functional deformities. We present our case-load of 2007: 61 patients operated in that year had been carried out and concluded. Surgical techniques for the correction of columellar defects were classified as "open tip" and "closed tip". Then, depending on the defect, it was possible to intervene on different structures. Of the 61 patients who underwent corrective surgery, only 6 (<10%) maintained or presented again, after a temporary improvement, with the columellar defect at the end of the follow-up. For all the other patients, the final outcome was more than satisfactory. A very good aesthetic result was obtained with no functional complications. In fact, nose functionality is supported by medial crura, laid one upon the other, providing considerable resistance to the columella.

Frontal sinus fractures: a review of 132 cases

BACKGROUND

Frontal sinus fractures peculiarity is that a wrong treatment not only could it encompass functional or aesthetical problems but also more dangerous complications: the proximity of the frontal bone to the brain, on a side, and to the nasolacrimal duct, on the other side, and therefore to the nasal cavity, lead the traumatisms occurring within this region to be at high risk of infections.

MATERIALS AND METHODS

We report our experience on 132 cases of frontal sinus fracture treated from 1989 to 2005 and to present the surgical techniques performed as well as to compare the complications they reported over time to the International Literature data. 101 patients (76.5%) were treated in order to reduce and contain the isolated fractures involving the frontal sinus anterior wall, the patients presenting associated fractures of the frontal sinus anterior and posterior wall were 28 (21.2%), while the cases reporting isolated fractures of the nasolacrimal duct were 3.

RESULTS

Our patients underwent follow-ups from 1 to 16 years long. We subdivided the complications found in our group into infectious and functional so that the incidence of the complications related to the sites and the treatment performed according to the specific case could be better assessed. In conclusion, the infectious and functional complications found were treated with a multidisciplinary study considering the approach to the craniofacial traumatized person is subordinated to the co-existence of general and neurological conditions requiring for their resolution different approaches and times.

[A comparison between traditional mammography and digital with storage phosphors]

Conventional and digital mammographic images obtained with storage phosphors were compared. The digital images were acquired with high-resolution 3rd-generation (HR III) screens and specifically adapted algorithms. The experience was made both on a phantom and in vivo. The phantom study was carried out by comparing conventional with digital radiographs acquired with: a) same kV (28) and same mAs; b) same kV (24) and same mAs; c) 28 kV with 30% mAs reduction, in digital images only. The results obtained upon counting the amount of recognizable details per image demonstrated slight loss of information in digital radiographs only when mAs was reduced by 30%. Two hundred patients were studied; they were divided into four groups according to the type of breast (medium inherent contrast or solid breast) and to exposure factors. After conventional mammography, an additional digital radiograph was performed using one of the three techniques previously employed on the phantom. Separately, 10 ductogalactographies and 10 magnification radiographs of microcalcifications were compared; the same exposure factors were used in these images too. The radiographs were viewed by three expert mammographic radiologists; contrast quality and spatial resolution were investigated and a score was given to each image on a 3-grade scale (insufficient, sufficient, good). The comparison of the mean values obtained showed higher contrast and better enhancement of nodular lesions on digital images, on which, however, the depiction of microcalcifications was worse than on conventional radiographs, especially with lower radiation doses, even though the number of detected microcalcifications was the same.

[Digital radiology with storage phosphors in cephalometric study in orthodontics]

Conventional radiology is continually modified with the development of digital systems which can be used for several types of radiologic examinations. Our study was aimed at evaluating the advantages of these new technologies in the orthodontic field, where the problems associated with image quality and radiation protection are major especially in young patients; the latter goal is achievable by dramatically reducing radiation dose and by avoiding repeating the exam. In our study, we compared lateral teleradiographs of the skull for cephalometric analysis obtained using conventional and digital diagnostic methods. The preliminary results demonstrated that the two imaging techniques did not differ relative to bone structure representation, even though the digital system provided better visualization of soft tissue structures. Computed radiography also allowed a marked reduction in the number of repeats and reduced radiation dose. The current disadvantages of this imaging method are the high initial cost of the equipment, reduced work rate, and the need of frequent technical assistance.

[Radiologic study of the thorax using the digital method (FCR 101). Evaluation of various parameters as related to exposure]

A computed radiography system with solid state detectors (FCR 101) was employed to evaluate the quality of digital images, with optimal and progressively lowered doses, in the study of the chest. Routine chest radiographs of in patients with no pathologic conditions of the chest were studied. The patients were divided into 3 groups: each patient in group A underwent two radiographs, one at 100% and the other at 50% exposure; patients in group B were imaged with 100% and 25% doses, and those in group C received 50% and 25% exposure. Several parameters were employed for image evaluation, and a value was given to each of them (1 = good, 2 = sufficient, 3 = insufficient). Upon comparison of the average values obtained, we observed that the digital technique allowed a most accurate and well-defined representation of the examined parameters at 100% exposure dose and that a 50% reduction did not decrease the informative content in the least. A 25% reduction, however, determined a high degree of background noise and a subsequent, though slight, loss of information.

[Double-contrast enema. Study of the mucosal pattern and the organ profile with conventional and digital methods]

A solid state digital system (FCR 101) was employed in our comparative evaluation of the image quality of conventional versus digital techniques in the study of colon by means of double-contrast enema. Sixty patients were examined with a single AP view, using digital radiography with 100% radiation dose and progressive 50% and 75% reductions; the radiographs thus obtained were then compared with the corresponding conventional ones. The examined parameters were organ profile and mucosal pattern. Each digital and conventional radiograph was evaluated by 2 independent radiologists and a value was given to each parameter i.e., 1 = good, 2 = sufficient, 3 = insufficient. Upon comparison of the average values obtained for digital and conventional radiographs in optimal conditions and with a dose reduced by 50%, the digital technique was seen to give a more detailed and accurate representation of both low-contrast mucosal pattern and of organ profile. With the dose reduced by 75%, a slight increase was observed in background noise which caused a slight loss in image definition, but this did not reduce image readability with respect to conventional radiographs. To conclude, the digital method with a 50% exposure reduction is to be preferred in the examination of the colon, especially in pediatric radiology; furthermore, since this technique allows better detailing at lower contrast, it is to be preferred in the study of the pathologic conditions affecting mainly/only the mucosal pattern--e.g., cancer, ulcerative colitis, Crohn's disease, and so on. An exposure dose reduced by 75% may be used for following lesions previously diagnosed and when a less detailed depiction of the mucosal pattern is enough.

Microalbuminuria and casual and ambulatory blood pressure monitoring in normotensives and in patients with borderline and mild essential hypertension

Several reports suggest that urinary albumin excretion may be elevated in patients with essential hypertension and that this index may be a good predictor for cardiovascular complications. The aim of this study was to compare 24-hour urinary albumin excretion in a group of normotensives, borderline, and untreated mild hypertertensives and to assess, in a subgroup of them, the possible relations between microalbuminuria and arterial blood pressure. Fifteen normotensives, 16 borderline, and 19 mild hypertensive patients were studied. Slightly but significantly higher values of microalbuminuria were observed in the mild hypertensives compared to the other two groups. In 21 borderline and mild hypertensive patients 24-hour microalbuminuria was related to casual blood pressure and noninvasive ambulatory blood pressure monitoring. A significant correlation was found between microalbuminuria and average day-time diastolic blood pressure. Our data suggest that albumin excretion is slightly increased in mild arterial essential hypertension; the direct association between microalbuminuria and arterial diastolic blood pressure during daily activities seems to confirm a pathophysiological link between transcapillary protein escape and arterial blood pressure that warrants further studies.

Renal scintigraphic captopril test in the diagnosis of renovascular hypertension

Angiotensin converting enzyme (ACE) inhibitor-induced renal failure has been reported in bilateral renal artery stenosis and in stenosis in solitary kidneys, but not in unilateral renal artery stenosis. In these patients, however, a functional impairment of the kidney ipsilateral to the stenosis can often be detected after ACE inhibition by scintigraphic techniques employing glomerular radionuclide tracers like 99mTc-diethylenetriamine pentaacetic acid (DTPA). Dynamic renal scintigraphy with 99mTc-DTPA before and 1 hour after administration of captopril, 25 mg (renal scintigraphic captopril test; RSCT), was performed in a selected series of 39 hypertensive subjects with suspected renovascular hypertension. Changes in glomerular filtration rate induced by captopril on the individual kidney were estimated by assessing the early (120-180 seconds) DTPA uptake by the kidney. Values were expressed as the ratio between the kidney with the lower uptake and the contralateral one in 34 patients and as the ratio of the kidney counts to the injected dose in five patients with solitary kidneys, aortic coarctation, or both. Compared with precaptopril values, postcaptopril uptake decreased markedly in 14 subjects (-62.42 +/- 30.94 [SD]%; range, -25 to -100%) and decreased modestly or even increased in the other 25 (+0.57 +/- 9.83%; range, +28 to -13%). Of the 14 subjects considered to be RSCT-positive diagnostic workup revealed either established (10) or strongly suspected (2) renal artery stenosis in 12 and aortic coarctation in 2 subjects. In another patient with established renovascular hypertension, results of the RSCT were negative when performed in the supine position but became positive when repeated in the sitting position.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in renal function during physical and mental effort

Aim of the study was to evaluate the renal responses to physical and mental effort in essential hypertension by means of a non-invasive radioisotopic method. Renal uptake rate of Tc99m-DMSA was evaluated in 10 subjects. Starting from 5 to 15 minutes after dose injection counts over the kidney region were acquired by means of a gamma-camera time-activity curves were obtained for each kidney. In non-stimulated patients DMSA uptake rate increased regularly; in the remaining cases both isometric exercise and mental effort induced an abrupt reduction of the uptake rate which increased again after the end of the test. Although the relation of DMSA uptake rate to renal function is not yet fully understood, we tentatively interpret these results as indicating blood flow reductions during these stressful conditions.

Acute effect of captopril on single kidney glomerular filtration rate in arterial hypertension

Recent studies have reported that captopril can acutely induce a marked decrease of glomerular filtration rate in kidneys affected by renal artery stenosis, an effect detectable by scintigraphic techniques. Experience which confirms and extends this observation, obtained in five patients with renovascular hypertension, is reported here. For comparison, eight essential hypertensives and six patients with non-vascular unilateral renal diseases were studied. In each patient the ratio of glomerular filtration rate between the two kidneys was estimated during two consecutive scintigraphic studies with the glomerular tracer 99mTc-DTPA: in all renovascular patients captopril induced a marked decrease of glomerular filtration rate on the affected side, whereas negligible changes were observed in all other subjects. These results confirm that captopril may almost completely suppress glomerular filtration in kidneys affected by unilateral renal artery stenosis, an effect which may not be apparent clinically because of compensation by the other kidney, but which is scintigraphically detectable. Renal scintigraphy after captopril is easy to perform and non-invasive. It therefore seems to be a promising tool for the screening of renovascular hypertension.

Arterial blood pressure and the renin-angiotensin-aldosterone system during postural changes in hypertensive patients with unilateral renal mobility

Unilateral renal mobility was identified in 27 out of 100 essential hypertensive patients by examination of renal scintiphotos. The pattern of response to postural changes of blood pressure (BP), plasma renin activity (PRA) and plasma aldosterone concentration (PAC) was investigated in 11 patients with renal mobility and without treatment and compared with that of an age- and sex-matched group of untreated hypertensives without renal mobility. The patients with renal mobility had higher BP levels (X +/- SD mm Hg: supine 185 +/- 39/112 +/- 18 vs. 149 +/- 18/97 +/- 14; upright 167 +/- 38/108 +/- 17 vs. 144 +/- 7/93 +/- 10; p less than 0.05). Significant correlations were obtained in the patients with renal mobility (but not in those without renal mobility) between upright PRA and PAC (p less than 0.001), their postural variations (p less than 0.01) and between upright PRA (and PAC) and BP levels (p less than 0.05). The high prevalence of renal mobility in hypertension and the relationship observed between the activated renin-angiotensin-aldosterone system and BP in this condition suggest the importance of searching for unilateral renal mobility when examining the renin-angiotensin-aldosterone system in hypertensive patients, particularly during postural manoeuvres.

Kidney scintigraphy after ACE inhibition in the diagnosis of renovascular hypertension

Suppression of the renin-angiotensin system (RAS) by angiotensin converting enzyme (ACE) inhibition may induce renal failure in patients with bilateral renal artery stenosis. Recent scintigraphic studies with the glomerular tracer technetium-99m-diethylenetriaminepenta-acetate (99m-Tc DTPA) indicate that in patients with unilateral renal artery stenosis, glomerular filtration rate (GFR) may be markedly reduced in the affected kidney after inhibition of ACE. This finding reflects the important role of the RAS in maintaining GFR (by increasing postglomerular resistance) in states of low renal perfusion pressure. Preliminary observations suggest that this scintigraphic test might be useful in the detection of renovascular hypertension.