Uncontrollable hypertension in patients on hemodialysis: long-term treatment with captopril and salt subtraction

It has been suggested that an inappropriate relationship between renin and exchangeable sodium is responsible for the hypertension of patients with chronic renal failure. Long-term blockade of the renin system by captopril made it possible to test this hypothesis in 8 patients on maintenance hemodialysis. Captopril was administered orally in 2 daily doses of 25 to 200 mg. Previously, blood pressure averaged 179/105 +/- 6/3 (mean +/- SEM) pre- and 182/103 +/- 7/3 mm HG post-dialysis, despite intensive ultrafiltration and conventional antihypertensive therapy. The 4 patients with the highest plasma renin activity normalized their blood pressure with captopril alone, whereas in the 4 remaining patients, captopril therapy was complemented by salt subtraction which consisted in replacement of 1-2 liters of ultrafiltrate by an equal volume of 5% dextrose until blood pressure was controlled. After an average treatment period of 5 months, blood pressure of all 8 patients was reduced to 134/76 +/- 7/5 mm Hg (P less than 0.001) pre- and 144/81 +/- 9/5 mm Hg (P less than 0.001) post-dialysis without a significant change in body weight. The present data suggest that captopril alone or combined with salt subtraction normalizes blood pressure of patients on chronic hemodialysis with so called uncontrollable hypertension.

Comparison of multislice computerized tomography angiography and digital subtraction angiography in the postoperative evaluation of patients with clipped aneurysms.

OBJECT: In this study the accuracy of multislice computerized tomography (MSCT) angiography in the postoperative examination of clip-occluded intracranial aneurysms was compared with that of intraarterial digital subtraction (DS) angiography METHODS: Forty-nine consecutive patients with 60 clipped aneurysms (41 of which had ruptured) were studied with the aid of postoperative MSCT and DS angiography. Both types of radiological studies were reviewed independently by two observers to assess the quality of the images, the artifacts left by the clips, the completeness of aneurysm occlusion, the patency of the parent vessel, and the duration and cost of the examination. The quality of MSCT angiography was good in 42 patients (86%). Poor-quality MSCT angiograms (14%) were a result of the late acquisition of images in three patients and the presence of clip or motion artifacts in four. Occlusion of the aneurysm on good-quality MSCT angiograms was confirmed in all but two patients in whom a small (2-mm) remnant was confirmed on DS angiograms. In one patient, occlusion of a parent vessel was seen on DS angiograms but missed on MSCT angiograms. The sensitivity and specificity for detecting neck remnants on MSCT angiography were both 100%, and the sensitivity and specificity for evaluating vessel patency were 80 and 100%, respectively (95% confidence interval 29.2-100%). Interobserver agreements were 0.765 and 0.86, respectively. The mean duration of the examination was 13 minutes for MSCT angiography and 75 minutes for DS angiography (p < 0.05). Multislice CT angiography was highly cost effective (p < 0.01). CONCLUSIONS: Current-generation MSCT angiography is an accurate noninvasive tool used for assessment of clipped aneurysms in the anterior circulation. Its high sensitivity and low cost warrant its use for postoperative routine control examinations following clip placement on an aneurysm. Digital subtraction angiography must be performed if the interpretation of MSCT angiograms is doubtful or if the aneurysm is located in the posterior circulation.

Salt subtraction in patients on maintenance hemodialysis. Efficacy and limitations.

In 6 hypertensive patients with terminal renal failure maintained on hemodialysis, the effects of 'salt subtraction' and of sequential ultrafiltrating were evaluated. Following each of 3 weekly hemodialysis sessions, salt subtraction was carried out by ultrafiltrating 1 liter and simultaneously infusing an equal volume of 5% dextrose. This resulted in a net sodium loss without hypovolemia. After a 2-week period of this procedure, the blood pressure prior to dialysis was lower (156/76 +/- 12/5 mm Hg) than after a comparable number of sequential ultrafiltration sessions (181/88 +/- 10/6 mm Hg; mean +/- SEM). This difference was not statistically significant. At the same time, body weight was comparable at 64.4 +/- 3 and 64.7 +/- 4 kg, respectively. Neither plasma renin activity nor plasma catecholamines responded with a clear increase to either procedure. The limited effect on blood pressure and the renin system of a marked sodium removal during salt subtraction suggests that sodium must still be present in excess in these patients. The procedure of salt subtraction appears safe and subjectively well tolerated, but it can probably not be used as the sole means of decreasing total body sodium without associating dietary measures to reduce sodium intake.

Local re-inversion coronary MR angiography: arterial spin-labeling without the need for subtraction.

PURPOSE: To implement a double-inversion bright-blood coronary MR angiography sequence using a cylindrical re-inversion prepulse for selective visualization of the coronary arteries. MATERIALS AND METHODS: Local re-inversion bright-blood magnetization preparation was implemented using a nonselective inversion followed by a cylindrical aortic re-inversion prepulse. After an inversion delay that allows for in-flow of the labeled blood-pool into the coronary arteries, three-dimensional radial steady-state free-precession (SSFP) imaging (repetition/echo time, 7.2/3.6 ms; flip angle, 120 degrees, 16 profiles per RR interval; field of view, 360 mm; matrix, 512, twelve 3-mm slices) is performed. Coronary MR angiography was performed in three healthy volunteers and in one patient on a commercial 1.5 Tesla whole-body MR System. RESULTS: In all subjects, coronary arteries were selectively visualized with positive contrast. In addition, a middle-grade stenosis of the proximal right coronary artery was seen in one patient. CONCLUSION: A novel T1 contrast-enhancement strategy is presented for selective visualization of the coronary arteries without extrinsic contrast medium application. In comparison to former arterial spin-labeling schemes, the proposed magnetization preparation obviates the need for a second data set and subtraction.

Evaluation of peripheral arterial bypass grafts with multi-detector row CT angiography: comparison with duplex US and digital subtraction angiography.

PURPOSE: To assess the technical feasibility of multi-detector row computed tomographic (CT) angiography in the assessment of peripheral arterial bypass grafts and to evaluate its accuracy and reliability in the detection of graft-related complications, including graft stenosis, aneurysmal changes, and arteriovenous fistulas. MATERIALS AND METHODS: Four-channel multi-detector row CT angiography was performed in 65 consecutive patients with 85 peripheral arterial bypass grafts. Each bypass graft was divided into three segments (proximal anastomosis, course of the graft body, and distal anastomosis), resulting in 255 segments. Two readers evaluated all CT angiograms with regard to image quality and the presence of bypass graft-related abnormalities, including graft stenosis, aneurysmal changes, and arteriovenous fistulas. The results were compared with McNemar test with Bonferroni correction. CT attenuation values were recorded at five different locations from the inflow artery to the outflow artery of the bypass graft. These findings were compared with the findings at duplex ultrasonography (US) in 65 patients and the findings at conventional digital subtraction angiography (DSA) in 27. RESULTS: Image quality was rated as good or excellent in 250 (98%) and in 252 (99%) of 255 bypass segments, respectively. There was excellent agreement both between readers and between CT angiography and duplex US in the detection of graft stenosis, aneurysmal changes, and arteriovenous fistulas (kappa = 0.86-0.99). CT angiography and duplex US were compared with conventional DSA, and there was no statistically significant difference (P >.25) in sensitivity or specificity between CT angiography and duplex US for both readers for detection of hemodynamically significant bypass stenosis or occlusion, aneurysmal changes, or arteriovenous fistulas. Mean CT attenuation values ranged from 232 HU in the inflow artery to 281 HU in the outflow artery of the bypass graft. CONCLUSION: Multi-detector row CT angiography may be an accurate and reliable technique after duplex US in the assessment of peripheral arterial bypass grafts and detection of graft-related complications, including stenosis, aneurysmal changes, and arteriovenous fistulas.

Use of limitations of radiolabeled anti-CEA antibodies and their fragments for photoscanning detection of human colorectal carcinomas.

Fifty-three patients with histologically proven carcinoma were injected with highly purified [131I]-labeled goat antibodies or fragments of antibodies against carcinoembryonic antigen (CEA). Each patient was tested by external photoscanning 4, 24, 36 and 48 h after injection. In 22 patients (16 of 38 injected with intact antibodies, 5 of 13 with F(ab')2 fragments and 1 of 2 with Fab' fragments), an increased concentration of 131I radioactivity corresponding to the previously known tumor location was detected by photoscanning 36-48 h after injection. Blood pool and secreted radioactivity was determined in all patients by injecting 15 min before scanning, [99mTc]-labeled normal serum albumin and free 99mTc04-. The computerized subtraction of 99mTc from 131I radioactivity enhanced the definition of tumor localization in the 22 positive patients. However, in spite of the computerized subtraction, interpretation of the scans remained doubtful for 12 patients and was entirely negative for 19 additional patients. In order to provide a more objective evaluation for the specificity of the tumor localization of antibodies, 14 patients scheduled for tumor resection were injected simultaneously with [131I]-labeled antibodies or fragments and with [125I]-labeled normal goat IgG or fragments. After surgery, the radioactivity of the two isotopes present either in tumor or adjacent normal tissues was measured in a dual channel scintillation counter. The results showed that the antibodies or their fragments were 2-4 times more concentrated in the tumor than in the normal tissues. In addition, it was shown that the injected antibodies formed immune complexes with circulating CEA and that the amount of immune complexes detectable in serum was roughly proportional to the level of circulating CEA.

Role of surgery in the management of brain arteriovenous malformations: prospective cohort study.

BACKGROUND AND PURPOSE: Management of brain arteriovenous malformation (bAVM) is controversial. We have analyzed the largest surgical bAVM cohort for outcome. METHODS: Both operated and nonoperated cases were included for analysis. A total of 779 patients with bAVMs were consecutively enrolled between 1989 and 2014. Initial management recommendations were recorded before commencement of treatment. Surgical outcome was prospectively recorded and outcomes assigned at the last follow-up visit using modified Rankin Scale. First, a sensitivity analyses was performed to select a subset of the entire cohort for which the results of surgery could be generalized. Second, from this subset, variables were analyzed for risk of deficit or near miss (intraoperative hemorrhage requiring blood transfusion of ≥2.5 L, hemorrhage in resection bed requiring reoperation, and hemorrhage associated with either digital subtraction angiography or embolization). RESULTS: A total of 7.7% of patients with Spetzler-Ponce classes A and B bAVM had an adverse outcome from surgery leading to a modified Rankin Scale >1. Sensitivity analyses that demonstrated outcome results were not subject to selection bias for Spetzler-Ponce classes A and B bAVMs. Risk factors for adverse outcomes from surgery for these bAVMs include size, presence of deep venous drainage, and eloquent location. Preoperative embolization did not affect the risk of perioperative hemorrhage. CONCLUSIONS: Most of the ruptured and unruptured low and middle-grade bAVMs (Spetzler-Ponce A and B) can be surgically treated with a low risk of permanent morbidity and a high likelihood of preventing future hemorrhage. Our results do not apply to Spetzler-Ponce C bAVMs.

Coronary magnetic resonance angiography for assessment of the stent lumen: a phantom study.

PURPOSE: To evaluate the feasibility of visualizing the stent lumen using coronary magnetic resonance angiography in vitro. MATERIAL AND METHODS: Nineteen different coronary stents were implanted in plastic tubes with an inner diameter of 3 mm. The tubes were positioned in a plastic container filled with gel and included in a closed flow circuit (constant flow 18 cm/sec). The magnetic resonance images were obtained with a dual inversion fast spin-echo sequence. For intraluminal stent imaging, subtraction images were calculated from scans with and without flow. Subsequently, intraluminal signal properties were objectively assessed and compared. RESULTS: As a function of the stent type, various degrees of in-stent signal attenuation were observed. Tantalum stents demonstrated minimal intraluminal signal attenuation. For nitinol stents, the stent lumen could be identified, but the intraluminal signal was markedly reduced. Steel stents resulted in the most pronounced intraluminal signal voids. CONCLUSIONS: With the present technique, radiofrequency penetration into the stents is strongly influenced by the stent material. Thesefindings may have important implicationsforfuture stent design and stent imaging strategies.

Estimates of radiation-absorbed dose to kidneys in patients treated with 90Y-ibritumomab tiuxetan.

The aim of the present study was to retrospectively estimate the absorbed dose to kidneys in 17 patients treated in clinical practice with 90Y-ibritumomab tiuxetan for non-Hodgkin's lymphoma, using appropriate dosimetric approaches available. METHODS: The single-view effective point source method, including background subtraction, is used for planar quantification of renal activity. Since the high uptake in the liver affects the activity estimate in the right kidney, the dose to the left kidney serves as a surrogate for the dose to both kidneys. Calculation of absorbed dose is based on the Medical Internal Radiation Dose methodology with adjustment for patient kidney mass. RESULTS: The median dose to kidneys, based on the left kidney only, is 2.1 mGy/MBq (range, 0.92-4.4), whereas a value of 2.5 mGy/MBq (range, 1.5-4.7) is obtained, considering the activity in both kidneys. CONCLUSIONS: Irrespective of the method, doses to kidneys obtained in the present study were about 10 times higher than the median dose of 0.22 mGy/MBq (range, 0.00-0.95) were originally reported from the study leading to Food and Drug Administration approval. Our results are in good agreement with kidney-dose estimates recently reported from high-dose myeloablative therapy with 90Y-ibritumomab tiuxetan.

When solving 22-7 is much more difficult than 99-12.

We describe the case of a 69-year-old professor of mathematics (GV) who was examined 2 years after left-hemispheric capsular-thalamic haemorrhage. GV showed disproportionate impairment in subtractions requiring borrowing (22 - 7). For large subtraction problems without borrowing (99 - 12) performance was almost flawless. Subtractions with borrowing mostly relied on inadequate attempts to invert subtractions into the corresponding additions (22 - 7 = x as 7 + x = 22). The hypothesis is advanced that difficulty in the inhibitory components of attention tasks (Stroop test, go-no-go task) might be the responsible factor of his calculation impairment. A deficit in subtractions with borrowing might be related to left-hemispheric damage involving thalamo-cortical connections.

Enhancement by diuretics of the antihypertensive action of long-term angiotensin converting enzyme blockade

Thirty-nine patients with various types of hypertension were treated by chronic blockage of the angiotensin converting enzyme, i.e. by twice daily administration of captopril, 50 to 200 mg p.o. The blood pressure reduction observed 1 hour following administration of the inhibitor was directly related to the baseline plasma renin activity (r=- 0.67, p < 0.001). Whenever blockade of the renin system alone did not lower blood pressure to normal levels additional sodium subtraction brought it under control. With the renin system neutralized, blood pressure becomes exquisitely sensitive to changes in sodium balance. Diuretics seem to preserve optimal natriuretic efficacy despite blood pressure reduction, probably because aldosterone levels are reduced and renal blood flow increases. Blockade of the renin system together with individually tailored salt subtraction provides an attractive new approach to long-term treatment of clinical hypertension.

The molecular signature of the stroma response in prostate cancer-induced osteoblastic bone metastasis highlights expansion of hematopoietic and prostate epithelial stem cell niches.

The reciprocal interaction between cancer cells and the tissue-specific stroma is critical for primary and metastatic tumor growth progression. Prostate cancer cells colonize preferentially bone (osteotropism), where they alter the physiological balance between osteoblast-mediated bone formation and osteoclast-mediated bone resorption, and elicit prevalently an osteoblastic response (osteoinduction). The molecular cues provided by osteoblasts for the survival and growth of bone metastatic prostate cancer cells are largely unknown. We exploited the sufficient divergence between human and mouse RNA sequences together with redefinition of highly species-specific gene arrays by computer-aided and experimental exclusion of cross-hybridizing oligonucleotide probes. This strategy allowed the dissection of the stroma (mouse) from the cancer cell (human) transcriptome in bone metastasis xenograft models of human osteoinductive prostate cancer cells (VCaP and C4-2B). As a result, we generated the osteoblastic bone metastasis-associated stroma transcriptome (OB-BMST). Subtraction of genes shared by inflammation, wound healing and desmoplastic responses, and by the tissue type-independent stroma responses to a variety of non-osteotropic and osteotropic primary cancers generated a curated gene signature ("Core" OB-BMST) putatively representing the bone marrow/bone-specific stroma response to prostate cancer-induced, osteoblastic bone metastasis. The expression pattern of three representative Core OB-BMST genes (PTN, EPHA3 and FSCN1) seems to confirm the bone specificity of this response. A robust induction of genes involved in osteogenesis and angiogenesis dominates both the OB-BMST and Core OB-BMST. This translates in an amplification of hematopoietic and, remarkably, prostate epithelial stem cell niche components that may function as a self-reinforcing bone metastatic niche providing a growth support specific for osteoinductive prostate cancer cells. The induction of this combinatorial stem cell niche is a novel mechanism that may also explain cancer cell osteotropism and local interference with hematopoiesis (myelophthisis). Accordingly, these stem cell niche components may represent innovative therapeutic targets and/or serum biomarkers in osteoblastic bone metastasis.

Role of surgery in the management of brain arteriovenous malformations: prospective cohort study.

BACKGROUND AND PURPOSE: Management of brain arteriovenous malformation (bAVM) is controversial. We have analyzed the largest surgical bAVM cohort for outcome. METHODS: Both operated and nonoperated cases were included for analysis. A total of 779 patients with bAVMs were consecutively enrolled between 1989 and 2014. Initial management recommendations were recorded before commencement of treatment. Surgical outcome was prospectively recorded and outcomes assigned at the last follow-up visit using modified Rankin Scale. First, a sensitivity analyses was performed to select a subset of the entire cohort for which the results of surgery could be generalized. Second, from this subset, variables were analyzed for risk of deficit or near miss (intraoperative hemorrhage requiring blood transfusion of ≥2.5 L, hemorrhage in resection bed requiring reoperation, and hemorrhage associated with either digital subtraction angiography or embolization). RESULTS: A total of 7.7% of patients with Spetzler-Ponce classes A and B bAVM had an adverse outcome from surgery leading to a modified Rankin Scale >1. Sensitivity analyses that demonstrated outcome results were not subject to selection bias for Spetzler-Ponce classes A and B bAVMs. Risk factors for adverse outcomes from surgery for these bAVMs include size, presence of deep venous drainage, and eloquent location. Preoperative embolization did not affect the risk of perioperative hemorrhage. CONCLUSIONS: Most of the ruptured and unruptured low and middle-grade bAVMs (Spetzler-Ponce A and B) can be surgically treated with a low risk of permanent morbidity and a high likelihood of preventing future hemorrhage. Our results do not apply to Spetzler-Ponce C bAVMs.

Pulsatile tinnitus caused by an aneurysm of the transverse-sigmoid sinus: a new case report and review of literature.

A 28-year-old woman consulted for disabling pulsatile tinnitus. Clinical examination suggested a venous etiology. An aneurysm of the transverse-sigmoid sinus was identified on computed tomography angiography (CTA) and confirmed by digital subtraction angiography. Endovascular occlusion of the aneurysm with detachable coils permanently eliminated the bruit. Thus, this report is of a new case of pulsatile tinnitus caused by an aneurysm of the transverse-sigmoid sinus, with a focus on a literature review and etiopathophysiology. Embryological studies suggest that these aneurysms represent a partial remnant of the petrosquamous sinus.