A marine isotope stage 13 Acheulian sequence from the Amanzi Springs Area 2 Deep Sounding excavation, Eastern Cape, South Africa.

Renewed research at Amanzi Springs has increased resolution on the timing and technology of the Acheulian industry in South Africa. The archeology from the Area 1 spring eye has recently been dated to MIS 11 (∼404-390 ka), and analyses revealed significant technological variability when compared to other southern African Acheulian assemblages. We expand on these results in presenting new luminescence dating and technological analyses of Acheulian stone tools from three artifact-bearing surfaces exposed within the White Sands unit of the Deep Sounding excavation in the Area 2 spring eye. The two lowest surfaces (Surfaces 3 and 2) are sealed within the White Sands and dated between ∼534 to 496 ka and ∼496 to 481 ka (MIS 13), respectively. Surface 1 represents materials deflated onto an erosional surface that cut the upper part of the White Sands (∼481 ka; late MIS 13), which occurred before the deposition of younger Cutting 5 sediments (<408-<290 ka; MIS 11-8). Archaeological comparisons reveal that the older Surface 3 and 2 assemblages are predominated by unifacial and bifacial core reduction and relatively thick, cobble-reduced large cutting tools. In contrast, the younger Surface 1 assemblage is characterized by discoidal core reduction and thinner large cutting tools, mostly made from flake blanks. Typological similarities between the older Area 2 White Sands and younger Area 1 (404-390 ka; MIS 11) assemblages further suggest long-term continuity in site function. We hypothesize Amanzi Springs represent a workshop locality that Acheulian hominins repeatedly visited to access unique floral, faunal, and raw material resources from at least ∼534 to 390 ka.

Back to the Future: From Appendage Development Toward Future Human Hair Follicle Neogenesis.

Hair disorders such as alopecia and hirsutism often impact the social and psychological well-being of an individual. This also holds true for patients with severe burns who have lost their hair follicles (HFs). HFs stimulate proper wound healing and prevent scar formation; thus, HF research can benefit numerous patients. Although hair development and hair disorders are intensively studied, human HF development has not been fully elucidated. Research on human fetal material is often subject to restrictions, and thus development, disease, and wound healing studies remain largely dependent on time-consuming and costly animal studies. Although animal experiments have yielded considerable and useful information, it is increasingly recognized that significant differences exist between animal and human skin and that it is important to obtain meaningful human models. Human disease specific models could therefore play a key role in future therapy. To this end, hair organoids or hair-bearing skin-on-chip created from the patient's own cells can be used. To create such a complex 3D structure, knowledge of hair genesis, i.e., the early developmental process, is indispensable. Thus, uncovering the mechanisms underlying how HF progenitor cells within human fetal skin form hair buds and subsequently HFs is of interest. Organoid studies have shown that nearly all organs can be recapitulated as mini-organs by mimicking embryonic conditions and utilizing the relevant morphogens and extracellular matrix (ECM) proteins. Therefore, knowledge of the cellular and ECM proteins in the skin of human fetuses is critical to understand the evolution of epithelial tissues, including skin appendages. This review aims to provide an overview of our current understanding of the cellular changes occurring during human skin and HF development. We further discuss the potential implementation of this knowledge in establishing a human in vitro model of a full skin substitute containing hair follicles and the subsequent translation to clinical use.

Efficacy of Pre-Operative Antimicrobial Prophylaxis in Patients Undergoing Pancreatoduodenectomy: A Multi-Center Retrospective Analysis.

BACKGROUND: The most common complications after pancreaticoduodenectomy (PD) are infectious, despite the standard use of cefazolin and metronidazole prophylaxis. Pre-operative biliary drainage (PBD) is a well-known risk factor for infectious complications. The objective was to identify the pathogens in intra-operative bile cultures in patients undergoing PD-with and without PBD-to determine the optimal antimicrobial prophylaxis regimen. PATIENTS AND METHODS: Patients who underwent PD between 2009 and 2016 were identified retrospectively in three major teaching hospitals in The Netherlands. Organisms isolated from intra-operative bile cultures were studied. If pathogen coverage by standard prophylaxis was incomplete, the most appropriate alternative regimen was determined. RESULTS: Of this large cohort of 352 patients, 56% underwent PBD and 44% did not. Positive bile cultures were found in 87.9% in the PBD group, compared with 31.8% in the non-PBD group. The micro-organisms isolated most commonly were Enterococcus, Streptococcus, and Klebsiella species. Cefazolin and metronidazole were appropriate in only 71% of patients. Adding gentamicin would provide complete coverage in 99% of PBD and 100% of non-PBD patients. CONCLUSIONS: Our data confirm that PBD prior to PD leads to microbial colonization and antibiotic resistance. To potentially prevent infectious complications, gentamicin may be added to the standard antimicrobial prophylaxis.

Variation in hospital mortality after pancreatoduodenectomy is related to failure to rescue rather than major complications: a nationwide audit.

BACKGROUND: In the mandatory nationwide Dutch Pancreatic Cancer Audit, rates of major complications and Failure to Rescue (FTR) after pancreatoduodenectomy between low- and high-mortality hospitals are compared, and independent predictors for FTR investigated. METHODS: Patients undergoing pancreatoduodenectomy in 2014 and 2015 in The Netherlands were included. Hospitals were divided into quartiles based on mortality rates. The rate of major complications (Clavien-Dindo ≥3) and death after a major complication (FTR) were compared between these quartiles. Independent predictors for FTR were identified by multivariable logistic regression analysis. RESULTS: Out of 1.342 patients, 391 (29%) developed a major complication and in-hospital mortality was 4.2%. FTR occurred in 56 (14.3%) patients. Mortality was 0.9% in the first hospital quartile (4 hospitals, 327 patients) and 8.1% in the fourth quartile (5 hospitals, 310 patients). The rate of major complications increased by 40% (25.7% vs 35.2%) between the first and fourth hospital quartile, whereas the FTR rate increased by 560% (3.6% vs 22.9%). Independent predictors of FTR were male sex (OR = 2.1, 95%CI 1.2-3.9), age >75 years (OR = 4.3, 1.8-10.2), BMI ≥30 (OR = 2.9, 1.3-6.6), histopathological diagnosis of periampullary cancer (OR = 2.0, 1.1-3.7), and hospital volume <30 (OR = 3.9, 1.6-9.6). CONCLUSIONS: Variations in mortality between hospitals after pancreatoduodenectomy were explained mainly by differences in FTR, rather than the incidence of major complications.

Nationwide prospective audit of pancreatic surgery: design, accuracy, and outcomes of the Dutch Pancreatic Cancer Audit.

BACKGROUND: Auditing is an important tool to identify practice variation and 'best practices'. The Dutch Pancreatic Cancer Audit is mandatory in all 18 Dutch centers for pancreatic surgery. METHODS: Performance indicators and case-mix factors were identified by a PubMed search for randomized controlled trials (RCT's) and large series in pancreatic surgery. In addition, data dictionaries of two national audits, three institutional databases, and the Dutch national cancer registry were evaluated. Morbidity, mortality, and length of stay were analyzed of all pancreatic resections registered during the first two audit years. Case ascertainment was cross-checked with the Dutch healthcare inspectorate and key-variables validated in all centers. RESULTS: Sixteen RCT's and three large series were found. Sixteen indicators and 20 case-mix factors were included in the audit. During 2014-2015, 1785 pancreatic resections were registered including 1345 pancreatoduodenectomies. Overall in-hospital mortality was 3.6%. Following pancreatoduodenectomy, mortality was 4.1%, Clavien-Dindo grade ≥ III morbidity was 29.9%, median (IQR) length of stay 12 (9-18) days, and readmission rate 16.0%. In total 97.2% of >40,000 variables validated were consistent with the medical charts. CONCLUSIONS: The Dutch Pancreatic Cancer Audit, with high quality data, reports good outcomes of pancreatic surgery on a national level.

Isolation, expansion and neural differentiation of stem cells from human plucked hair: a further step towards autologous nerve recovery.

Stem cells from the adult hair follicle bulge can differentiate into neurons and glia, which is advantageous for the development of an autologous cell-based therapy for neurological diseases. Consequently, bulge stem cells from plucked hair may increase opportunities for personalized neuroregenerative therapy. Hairs were plucked from the scalps of healthy donors, and the bulges were cultured without prior tissue treatment. Shortly after outgrowth from the bulge, cellular protein expression was established immunohistochemically. The doubling time was calculated upon expansion, and the viability of expanded, cryopreserved cells was assessed after shear stress. The neuroglial differentiation potential was assessed from cryopreserved cells. Shortly after outgrowth, the cells were immunopositive for nestin, SLUG, AP-2α and SOX9, and negative for SOX10. Each bulge yielded approximately 1 × 10(4) cells after three passages. Doubling time was 3.3 (±1.5) days. Cellular viability did not differ significantly from control cells after shear stress. The cells expressed class III ß-tubulin (TUBB3) and synapsin-1 after 3 weeks of neuronal differentiation. Glial differentiation yielded KROX20- and MPZ-immunopositive cells after 2 weeks. We demonstrated that human hair follicle bulge-derived stem cells can be cultivated easily, expanded efficiently and kept frozen until needed. After cryopreservation, the cells were viable and displayed both neuronal and glial differentiation potential.

Advances in hair transplantation: longitudinal partial follicular unit transplantation.

There are different techniques of hair transplantation. The most common and known hair transplantation methods are the 'strip' method, where a strip of skin containing hair follicles is removed, cut into grafts and implanted in the recipient area, and the follicle unit extraction (FUE) method, in which whole follicle units are extracted one by one and implanted one by one back into the recipient area. The FUE method is more patient friendly and leaves only tiny scars compared to the strip method, which leaves visible linear scars at the donor area. Both methods, however, have the major disadvantage that the extracted hair follicles are removed and the availability of donor hair follicles are limited and results in a decrease in hair density, as no re-grow will occur in the donor area. Since partial longitudinal-follicular unit transplantation (PL-FUT) extracts partial longitudinal follicular units that can be used as complete follicular units to regenerate completely differentiated hair growth and the partial follicular units that remain in the dermis in the donor area can survive and produce hair, PL-FUT enables us to multiply hair follicles in vivo while preserving the donor area. Although this technique is suitable for androgenic alopecia, PL-FUT could also be suitable in persons who have a relative small donor area compared to the recipient area like burn victims, as well as scarring alopecia's like frontal fibrosing alopecia.

The influence of preservation solution on the viability of grafts in hair transplantation surgery.

SUMMARY: Hair transplantation techniques have changed in the last decades. Partial longitudinal follicular unit transplantation is a new hair transplantation technique, which differs from all other hair transplantation techniques by the size of the graft and therefore much more vulnerable grafts compared to the conventional hair transplantation grafts. In this study, we reveal the influence of the preservation solution on the viability of the grafts. We have extracted 15 hair transplantation grafts of 0.6 mm and 15 hair transplantation grafts of 0.7 mm from 3 different patients and investigated the influence of 2 commercially available preservation media, saline solution (Braun, Melsungen, Germany) and Ringer's lactate (Braun), on the viability of grafts and compared these solutions with the preservation solution developed by Hair Science Institute with trypan blue. The grafts stored in the preservation solution developed by Hair Science Institute showed a significant better viability compared with the 2 commercially available preservation media saline solution and Ringer's lactate. This study shows that a preservation solution could influence the viability of the grafts which could be essential for hair transplantations with small grafts such as in partial longitudinal follicular unit transplantation.

[Therapeutic options for androgenetic alopecia]. / Therapeutische opties bij androgenetische alopecia.

Androgenetic alopecia (AGA) is the most common type of hair loss. There are different treatment possibilities for the prevention of and as a remedy for AGA. The broad spectrum of possibilities varies from doing nothing to hair transplantation. Treating AGA is difficult because it is a natural, ongoing and personal process. The progression of AGA can be slowed down by medication. If one desires a full head of hair and immediate results, however, a hairpiece could be an option. A permanent result is only attainable by hair transplantation. In terms of cost effectiveness over the short term (1 year) and intermediate term (10 years), medication is the best option. Hair transplantation, however, remains the best solution for a permanent result over the long term (more than 10 years). Given the advantages of partial longitudinal follicle unit transplantation (PL-FUT) in comparison with traditional hair transplantation techniques, our preferences go out to PL-FUT and medicinal treatment.

Improved hair restoration method for burns.

BACKGROUND: Extracted partial longitudinal follicular units can be used as complete follicular units to regenerate completely differentiated hair growth. The partial follicular units that remained in the dermis in the donor area can survive and produce hairs. This technique enables us to multiply hair follicles in vivo, while preserving the donor area and therefore is suitable in persons, who have a relative small donor area compared to the recipient area, as in scalp burns. OBJECTIVES: With this study, we try to determine if partial longitudinal follicular unit transplantation (PL-FUT) can be used for facial and/or scalp burns. MATERIALS AND METHODS: Four burn victims (age 22-39 years, mean 27.75 years) were treated in the face (eyebrows, and beard) and/or on the scalp with PL-FUT. The grafts were harvested with hollow wave-tipped needles with an inner diameter of 0.6mm from the occipital area of the scalp. The suitable longitudinal partial follicular units were impregnated with a preservative medium, and implanted into the recipient area. Hair growth in the donor area as well as the recipient area was observed before treatment, and at intervals of 1 week, 3 months and 1 year after the treatment. RESULTS: After evaluation of the donor area, sometimes a few little white spots were visible, but almost all hair follicles in the donor site re-produce hairs after 2 years. All treated patients had satisfactory or very satisfactory cosmetic results in the treated area. CONCLUSIONS: Longitudinal partial follicular unit transplantation (LP-FUT) may represent the first reliable patient-friendly method to generate two hair follicles from one hair follicle with consistent results and preservation of the donor area. Therefore, this method is very suitable for people with facial and/or scalp burns.

Medial artery calcification of uremic patients: a histological, histochemical and ultrastructural study.

Recent findings suggest that vascular calcification (VC) is an active process similar to bone mineralization, the vascular smooth muscle cells (VSMCs) undergoing phenotypic differentiation into osteoblastic cells and synthesizing calcification-regulating proteins found in bone. This study has investigated the VC process of uremic patients, with a morphologic approach. Epigastric artery samples from 49 uremic, non-diabetic patients were taken during kidney transplantation. Sections from paraffin-embedded samples were stained with hematoxylin/eosin and von Kossa. CD68 was immunohistochemically detected, and sections from frozen samples were stained with Oil Red O. Deeply calcified samples were stained with Picrosirius Red, PAS, and Alcian blue. Specimens from one patient with moderate and one with severe VC were examined under the electron microscope. None of the samples had atherosclerosis. Calcifications were found in the media of 38 patients. In 23, dot-like calcifications were irregularly scattered near the adventitia (light VC); in 11, granular calcifications formed concentric rings near the adventitia (moderate-advanced VC); in 4, zones of consolidated calcifications were found (severe VC). These zones were poor in collagen, glycoproteins and proteoglycans. In cases with moderate or severe VC, VSCMs showed necrotic changes. Matrix vesicles could be recognized in the extracellular spaces. In cases with severe VC, uncalcified or partially calcified membranous bodies were found, together with Liesegang rings. Patches of fibrin were also found. These findings point to a mainly degenerative mechanism of VC, which proceeds from the outer portion of the media. An active mechanism, however, cannot be excluded. A unifying hypothesis is suggested.

Donor hair follicle preservation by partial follicular unit extraction. A method to optimize hair transplantation.

BACKGROUND: There are different stem cell pools located in the hair follicle. OBJECTIVE: To try to determine whether follicular units can survive a partial extraction and whether this partial extracted follicular unit can regenerate new hairs. METHODS: From five individuals, between 100 and 150 grafts were harvested from the occipital area of the scalp. Suitable grafts were implanted into the recipient area. Hair growth and characteristics in the donor area and the recipient area were observed at different intervals. RESULTS: After 3 months, between 92.1% and 104.1% (mean 97.7%) of the partial follicular units in the donor sites survived and produced hairs with the same characteristics. After 1 year, 91.1­101.7% (mean 95.9%) of the implanted partial follicular units regenerated hair growth with the same characteristics as the hairs in the donor area. CONCLUSIONS: We revealed that extracted partial longitudinal follicular units transplanted to the recipient area can be used as complete follicular units to regenerate completely differentiated hair growth with the same characteristics as in the donor area. We also revealed that the partial follicular units in the donor area can survive and produce the same number of hairs with the same characteristics. This technique enables us to generate two hair follicles from one follicle with consistent results and preserve the donor area.

Bone turnover, osteopenia and vascular calcifications in hemodialysis patients. A histomorphometric and multislice CT study.

BACKGROUND: Several classical risk factors are at the base of vascular calcifications in hemodialysis patients. Among these, according to a general opinion, also bone turnover plays a role, which, however, requires a better definition. In addition, it has been suggested that there is a relationship between primary osteoporosis and vascular calcifications. This bone biopsy-based study on a hemodialysis patient cohort is a contribution to the evaluation of these alleged relations. METHODS: This study has been carried out on a cohort of 32 patients on maintenance hemodialysis, who were subjected to transiliac bone biopsy for histomorphometric, histodynamic and bone aluminum deposit evaluation. The patients were also examined with multislice computerized tomography for quantitation of heart and coronary calcifications. RESULTS: The patients were affected by renal osteodystrophy with a wide range of bone formation rate values. A significant negative correlation was found between the rate of bone turnover and log-transformed cardiac calcification score (p < 0.003). There were also negative significant correlations between the cardiac and coronary calcification score log and trabecular number (p < 0.02 and p < 0.05, respectively), while the correlations were positive with trabecular separation (p < 0.03 and p < 0.05, respectively). However, multiregression analysis, forward method, selected only age, hemodialysis age and serum Ca as predictive variables of cardiac and coronary calcification score log, while the histomorphometric and histodynamic variables were excluded. CONCLUSIONS: In this study, in spite of the suggestive findings of the univariate statistical approach, a further multivariate analysis was indicative of a spurious association between calcification scores and both bone turnover and histomorphometric parameters of trabecular mass and connectivity. Bone turnover and trabecular mass do not appear to be prominently connected with the extent of cardiac and coronary calcifications in hemodialysis patients.

High-dose calcitriol therapy and progression of cardiac vascular calcifications.

BACKGROUND: Dialysis patients show a very high prevalence of cardiovascular complications, affected as they are with abnormal and accelerated vascular calcifications and, eventually, calcium and phosphorous metabolism disorders. Multislice computed tomography (MSCT) provides a reproducible, high-resolution imaging of calcium contained in cardiac arteries, measured by Agatston score. The aim of the present study was to evaluate the influence of high-dose and low-dose calcitriol therapy on the progression of cardiac vascular calcifications in dialyzed patients. METHODS: We enrolled 36 dialyzed patients in a prospective study, including an interventional period of 12 months and a follow-up period of 12 months. Eighteen protocol patients received intravenous pulses of high-doses calcitriol at the end of dialytic treatment and sevelamer hydrochloride therapy. Control patients received low-dose calcitriol and sevelamer hydrochloride as well. Two MSCT scans were performed: 1 at the start of the study and 1 at the end of follow-up, and Agatston score was calculated at both examinations. RESULTS: At first examination, protocol patients showed almost the same level of cardiac vascular calcification as control patients. At the second MSCT, statistically significantly higher values of Agatston score were recorded for all patients. Indeed, patients who showed higher baseline values developed worse calcifications as recorded at the end of follow-up, both in the protocol and control group. CONCLUSIONS: Our data show that baseline level is strongly predictive of vascular calcification progression, and, moreover, there is no association between calcitriol administered doses and the progression of cardiac vascular calcification.

Cardiac calcifications in hemodialysis patients assessed with spiral computed tomography.

AIM: Cardiac disease is a major cause of mortality in uremic patients. The aim of this paper was to evaluate cardiac calcium content in uremic patients with multislice computed tomography (MSCT). METHODS: The study has been carried out on 120 uremic and 28 nonuremic patients affected by cardiovascular disease. Serum calcium, phosphorus, calcium-phosphate product, intact PTH were assayed. Several lipidic and nutritional parameters were measured. Calcification values obtained with the MSCT were reported in terms of Agatson scores. RESULTS: We found that the average score values in cohort on uremic was 10 times higher than in nonuremic patients (score values 3.389 vs 328). Cardiac calcification score was found to be correlated significantly to age (P=0.006), HD age (P=0.010), serum calcium (P=0.006), iPTH (P=0.004). Multiregression analysis (MRA) with the cardiac score as dependent variable selected the following variables (R(2) 0.612): age (P=0.002), HD age (P=0.010), serum cholesterol (P<0.000), triglycerides (P=0.001) and inversely HDL cholesterol (P=0.001) and non-HDL cholesterol (P=0.001) as predictive variables for cardiac score. By comparing patients with scores lower and higher than 400, the group with score <400 showed a significantly lower age (P=0.0001), HD vintage (P=0.01) and a significantly higher serum cholesterol (P=0.009), HDL cholesterol (P=0.05) and non-HDL cholesterol (P=0.05). CONCLUSIONS: The MSCT could help in identifying and stratifying high-risk patients to implement preventive strategies. The control of mineral metabolism and of lipid levels is important in prevention of arterial calcification in uremic patients.

[Can cardiovascular calcifications be prevented in chronic kidney disease?]. / E possibile prevenire i processi di calcificazione cardiovascolare nel paziente con insufficienza renale cronica?

Chronic kidney disease, with special regard to hemodialysis patients, develop frequent and widespread cardiac and vascular calcifications. In the heart calcifications are mainly located in the coronary arteries and in the valvular structures. There is a strict relation between cardiovascular mortality in CKD and the extent of cardiac and vascular calcifications. Therefore it is important to evaluate the causes of extraskeletal calcifications for the evaluation of the possibility of prevention. The importance of hyperphosphatemia, of hypercalcemia and of the increased CAxP product as a cause of cardiac calcification has been clearly underlined. However the mechanism of calcification, initially considered a physico-chemical precipitation, has been investigated with the conclusion that the process is mediated by cellular differentiation and production of factors favoring mineralization in the extracellular milieu. Increased serum phosphate levels are able to induce a transformation of vascular smooth muscle cells into osteoblast-like cells, able to produce factors known to be pro-mineralizing agents in the bone tissue. Further studies have revealed the importance of a number of inhibitors of calcification of cardiovascular structures, like Fetuin-A, MGP, Osteopontin, Osteoprotegerin. Therefore at present the calcification process of vascular tissue is considered to be linked to a balance between inducers and inhibitors of calcium-phosphate deposits. Prevention of cardiac calcifications is at present mainly based of optimal control of serum phosphate and reduction of calcium load through the use of non-calcium containing phosphate binders. Treatment with statins for prevention and treatment of atherosclerosis is also an important means of decreasing the size and number of atherosclerotic plaques, where a portion of the calcification process develops.

Diagnosis and outcome of renal function in patients with renal artery stenosis: which role have color Doppler sonography and magnetic resonance angiography?

AIM: Minimally invasive diagnostic techniques would be useful in the preoperative diagnosis of patients with hypertension and ischemic renal disease. The aim of our study was to compare color Doppler sonography (CDS), and magnetic resonance angiography (MRA) with the reference standard, digital subtraction angiography (DSA), in the diagnosis of renal artery stenosis. METHODS: Thirty-nine patients with arterial hypertension and monolateral or bilateral renal artery stenosis documented by CDS underwent renal artery MRA and then DSA during corrective percutaneous transluminal angioplasty. CDS and MRA scans were evaluated by 3 independent observers who studied 78 main renal arteries. Stenosis of 70% or more were regarded as significant. Sensitivity, specificity, positive and negative predictive values and two-sided 95% confidence intervals of CDS and MRA for the detection of significant renal artery stenosis were calculated. The statistical significance of the differences in sensitivities between CDS and MRA was assessed by means of the kappa test (< or =1). RESULTS: CDS and MRA, therefore, both achieved 97.6% sensitivity and 100% specificity for diagnosing stenoses at the origin of the renal artery; CDS yielded 100% sensitivity and 97.1% specificity and MRA 87.5% sensitivity and 98.6% specificity for diagnosing stenosis in the intermediate distal segments. CONCLUSIONS: Statistically significant differences between CDS and MRA in the diagnosis of renal artery stenosis have not been observed. However, according to our experience, CDS is the preferred technique because it also provides useful information about the development of kidney disease before correction.

Cardiac calcium evaluation in hemodialysis patients with multisection spiral computed tomography.

AIM: The aim of this study is cardiac calcium content evaluation in hemodialysis patients by a new technique, based on ultrafast multisection CT (MTC). METHODS: The study was carried out on 30 HD patients, 14 F and 16 M, average age 57.7 +/- 13.9 years, average HD age 57.3 +/- 47.4 months. The intact PTH levels were 625.4 +/- 571 pg/mL. Serum calcium, phosphate and CaxP product were 9.75 +/- 0.84 mg/mL, 6.21 +/- 1.01 mg/dL and 60.2 +/- 10.7 mg2/dL2, respectively. RESULTS: The values obtained with the MTC technique were reported in terms of Agatson scores. Score values frankly in the pathologic range (>100) were found in 24 patients (80%). Correlation analysis has shown positive and significant correlation coefficients of the score with patients' age (p = 0.003), serum calcium (p = 0.012), CaxP (p = 0.015), iPTH (p = 0.049), and borderline, to HD age (p = 0. 06). CONCLUSION: Risk factors for cardiac calcification are mainly age, degree of hyperparathyroidism, increased CaxP and serum calcium levels. A control of calcium phosphate parameters in hemodialysis patients seems to be mandatory to avoid increased severity of coronary artery disease.

Atherosclerotic ischemic renal disease.

AIM: Atherosclerotic ischemic renal disease is a frequent cause of end-stage renal failure leading to dialysis among the elderly; its prevalence is inferred from autopsy or retrospective arteriographic studies. Screening investigation for ischemic nephropathy on large cohorts, based on non invasive diagnostic techniques, have not so far been published. This study has been conducted on 269 subjects over 50 with hypertension and/or chronic renal failure, unrelated to other known causes of renal disease. METHODS: All 269 patients were studied either by color-flow duplex sonography (n=238) or by renal scintigraphy (n=224), and 199 of the 269 patients were evaluated using both of these techniques. Forty patients, found to have renal artery stenosis, were subjected to 3D-contrast enhancement magnetic resonance angiography (MRA) and/or digital selective angiography (DSA). An additional 23 cases, negative both to scintigraphy and to ultrasound study, underwent renal angiography (MRA and/or DSA). RESULTS: Color-duplex sonography, carried out in 238 patients, revealed 49 cases of renal artery stenosis. MR or DSA was carried out in 35 of these 49 patients, and confirmed the diagnosis in 33. Color-duplex sonography was 91.7% sensitive and 90.9% specific, with positive predictive value of 94.2% and negative predictive value of 86.9%. Specificity and sensitivity of renal scintigraphy, carried out in 224 patients, was significantly lower. Patients with renal artery stenosis showed a higher degree of renal insufficiency compared to non stenotic patients while there were no differences in the extent of proteinuria between the two groups. Renal artery stenosis, based on color-duplex sonography studies, was present in 11% of patients in the age group 50-59, 18% in the 60-69 and 23% at age 70 and above. CONCLUSION: A relatively large percentage of the elderly population with renal insufficiency and/or hypertension is affected by renal artery stenosis and is at risk of developing end-stage renal failure. Color-duplex ultrasonography is a valid routine method of investigation of population at risk for renal artery stenosis.

Could an echo contrast agent be helpful in identifying renal artery stenosis?

BACKGROUND: Diagnosis of renal artery stenosis using echo color-Doppler is subjected to several limitations. The aim of this study was to examine if the routine use of a contrast agent could be helpful in identifying renal artery stenosis (RAS). METHODS: We analysed 35 patients affected by RAS using an echo color-Doppler coupled with a contrast agent. All patients presented arterial hypertension, with a good drugs control, and mean serum creatinine of 1.8 mg/dL. All patients previously underwent angiography. RAS was at the origin of the artery in 27 patients, at the intermediate tract in 8. All patients had already been submitted to a basal echo color-Doppler. RESULTS: The contrast agent determined a significant increase in the average colour signal in all the subjects, and a better evaluation of the spectral waveforms, if compared to the basal examination. CONCLUSIONS: The results obtained showed that the contrast agent doesn't improve the diagnosis of RAS, especially in vascular origin stenosis, while it shows a real advantage in the intermediate or distal stenosis which are better visualized.