INCIDENTAL PARATHYROIDECTOMY DURING TOTAL THYROIDECTOMY AS A POSSIBLE RISK FACTOR OF HYPOCALCEMIA. EXPERIENCE OF A SINGLE CENTER AND REVIEW OF LITERATURE.

CONTEXT: Post-operative clinical and biochemical hypocalcemia is a common complication of thyroid surgery and the correlation with incidental parathyroidectomy (IP) remains controversial. OBJECTIVE: To evaluate the incidence of IP during TT, its correlation to early post-surgery hypocalcemia, and its potential risk factors. PATIENTS AND METHODS: 77 consecutive patients submitted to thyroid surgery between January 2018 and December 2019. Demographic, clinical, biochemical, surgical and histopathological factors were assessed. Statistical multivariate analysis was performed to identify the risk of IP. RESULTS: IP was evident in 22 (28.5%) patients who underwent TT, TT with lymph node dissection of the central compartment (CLND) and reoperation for previous hemithyroidectomy with CLND. Early symptomatic hypocalcemia 24 hours after TT was demonstrated in 12/22 (54.5%) patients, with PTH value of <14pg/mL in 7/12 (58.3%) patients, and in 6 of these 7 patients (85.7%) the PTH value was <6.3pg/mL. In 5/22 (22.7%) patients the IP was associated with biochemical hypocalcemia <8.4mg/dL, and in 5/22 (22.7%) patients anatomical damage was not associated with a reduction in plasma calcium levels. The severity of early post-op hypocalcemia was not correlated with the number of parathyroid glands left in situ. The multivariate analysis did not show statistically significant values between the clinical-pathological variables and increased risk of IP. CONCLUSIONS: No IP clinical-pathological risk factors have been identified during thyroid surgery. In all cases of TT, with or without CLND, the meticulous identification of the parathyroid glands, whose incidental removal is frequently associated with clinical and biochemical hypocalcemia, is recommended.

PET-guided Switch from Immunotherapy to Targeted Therapy in a Metastatic Melanoma Patient: a personalized approach.

An early identification of non-responders in oncology is of crucial importance to rapidly switch treatment regimens. Here we report a positron emission tomography, (PET)-guided switch from immunotherapy to targeted therapy in a patient affected by metastatic melanoma. We describe the case of a 78-years-old male patient diagnosed with nodular melanoma, submitted to baseline PET/CT with 18fluorodeoxyglucose (18F-FDG) that showed cutaneous and skeletal metastases (stage IV). The patients started immunotherapy with pembrolizumab. A PET/CT performed 3 months after the start of immunotherapy demonstrated progressive metabolic disease both at skeletal and cutaneous level, confirmed also by the biopsy. As patients resulted positive for BRAF V600k mutation, treatment regimen was rapidly switched to combined anti-BRAF/MEK targeted therapy. The PET/CT performed 3 months later, showed almost complete metabolic response. Ten months after the beginning of targeted therapy, the patient continues to present a durable metabolic response. PET/CT with 18F-FDG may help in monitoring the response to treatment in metastatic melanoma thus defining personalized therapeutic pathways.

Total thyroidectomy associated to chemotherapy in primary squamous cell carcinoma of the thyroid.

Primary squamous cell carcinoma of the thyroid (PSCCT) is a rare malignant disease with rapid fatal prognosis. The onset is generally characterized by sudden bilateral latero-cervical lymphadenopathy. The Authors report patient of 58-year-old who referred for evaluation of rapidly aggravating bilateral latero-cervical lymphadenopathy. The US highlighted the presence of a hypoechoic nodular lesion characterized by peri and intra-nodular vascularization. Multilayer CT showed diffused involvement of mediastinal and bilateral latero-cervical lymph nodes, with no evidence of primary pulmonary neoplasia or elsewhere. The patient underwent total thyroidectomy. The peri-isthmic tissue was removed due to the presence of a small roundish formation, that was due to lymph node metastasis at histological examination. Histological diagnosis: PSCCT. The immunohistochemical panel of the thyroid lesion was indispensable for the differential diagnosis between PSCCT, medullary carcinoma, anaplastic carcinoma, and thyroid metastasis of neoplasia with unknown primitiveness. The patient underwent chemotherapeutic treatment with Carboplatin and Paclitaxel with modest improvement of dysphagia symptoms and reduction of 10-15% of the target lesions. The clinical course was characterized by loco-regional progression of the disease with exitus in 10 months after diagnosis. Survival and quality of life after surgical therapy and chemotherapy were like that of patients undergoing only chemotherapy. Due to the extreme rarity of the neoplasia, 60 cases described in Literature, no exclusive guidelines are reported for PSCCT. More extensive case studies are needed to evaluate the effects of total thyroidectomy with intent R0/R1 on improving survival and quality of life of patients with PSCCT.

Primary HPV test screening in cervical cancer: a two-year experience of a single screening center in Latina (Italy).

OBJECTIVE: The aim of this study was to evaluate the effect and performance of the new algorithm in cervical cancer screening program in two years' experience of Latina (Italy). MATERIALS AND MTHODS: The female population was divided into two groups, the first group was referred to PAP test and the second one to hr-HPV test according to national guidelines. RESULTS: In two years the participation mean rate increased among women aged 35-64 compared to women aged 25-34. The primary PAP test positive rate and hr-HPV test positive rate were 4.0% and 5.2%, respectively. The PAP test positive rate among hr-HPV+ women decreased from 2012 to 2013. Women with hr-HPV+/PAP+ were referred immediately to colposcopy and this rate was 1.2%. The predictive positive value for CIN2+ to colposcopy was 10.9% in 2012 and 9.1% in 2013, while the detection rate for CIN2+ was 1.6% in 2012 and 1.4% in 2013. CONCLUSION: The stratification of the female population leads to a decreased inappropriate therapeutic path while the combination of hr-HPV test with PAP test in woman aged 35-64 lets obtain high levels specificity and sensitivity results.

The 16, 18, and 45 HPV infection in high grade squamous cervical lesions in primary hr-HPV test screening program.

Infection with high-risk human papillomavirus (hr-HPV) 16, 18, and 45 causes 94% of cervical carcinoma. In the present screening center the authors perform the hr-HPV test followed by Pap test to women aged 35-64 years if they result hr-HPV+. The authors' aimed to provide data regarding the genotyping test and eventually to propose this test as alternative to triage cytology. They used a genotyping test to identify HPV 16, 18, and 45 in 22 women with histological diagnosis of CIN2+, 22 women with histological diagnosis of CIN1 and 22 women hr-HPV+/Pap-. The group of CIN2+ showed the higher positivity to the test and the higher positivity to HPV 16 than other groups. Analyzing the clinical performance of the genotyping test the authors observed that the specificity was 64%. From these data they concluded that the identification of HPV 16 is predictive for high-grade lesions but this test could not be used alternatively to triage cytology.

Growth factors, their receptor expression and markers for proliferation of endothelial and neoplastic cells in human osteosarcoma.

Osteosarcoma is the most common primary malignant tumour of the bone. Although new therapies continue to be reported, osteosarcoma-related morbidity and mortality remain high. Modern medicine has greatly increased knowledge of the physiopathology of this neoplasm. Novel targets for drug development may be identified through an understanding of the normal molecular processes that are deeply modified in pathological conditions. The aim of the present study is to investigate, by immunohistochemistry, the localisation of different growth factors and of the proliferative marker Ki-67 in order to determine whether these factors are involved in the transformation of osteogenic cells and in the development of human osteosarcoma. We observed a general positivity for NGF - TrKA - NT3 - TrKC - VEGF in the cytoplasm of neoplastic cells and a strong expression for NT4 in the nuclear compartment. TGF-beta was strongly expressed in the extracellular matrix and vascular endothelium. BDNF and TrKB showed a strong immunolabeling in the extracellular matrix. Ki-67/MIB-1 was moderately expressed in the nucleus of neoplastic cells. We believe that these growth factors may be considered potential therapeutic targets in the treatment of osteosarcoma, although proof of this hypothesis requires further investigation.

Expression of phosphoinositide-specific phospholipase C enzymes in human skin fibroblasts.

Fibroblasts are involved in a number of functions regulated by different signal transduction pathways, including the phosphoinositide (PI) signaling system and related converting enzymes, such as phosphoinositide-specific phospholipase C (PI-PLC). The PI-PLC family comprises crucial effector enzymes in the PI signal transduction pathway. Once activated, PI-PLC cleaves an important membrane PI, the phosphatidylinositol (4,5) bisphosphate into inositol trisphosphate and diacylglycerol-both are crucial molecules in the transduction of signals. The activity of selected PI-PLC enzymes was reported in fibroblasts, although the complete panel of expression was not available. Each cell type expresses a group of selected PI-PLC isoforms, and knowledge of the panel of expression is a necessary and preliminary tool to address further studies. In the present study, we delineated the expression panel of PI-PLC enzymes in human skin fibroblasts. PI-PLC ß1, PI-PLC ß3, PI-PLC ß4, PI-PLC γ1, PI-PLC γ2, PI-PLC δ1, PI-PLC δ3, PI-PLC δ4, and PI-PLC ϵ were expressed. PI-PLC ß1 was weakly expressed, PI-PLC δ4 was inconstantly expressed, and PI-PLC γ2 was weakly expressed.

Rotator cuff re-tear or non-healing: histopathological aspects and predictive factors.

PURPOSE: The aim of the study was to evaluate the histopathological changes that occur in the tendon and subacromial bursal tissue in patients with rotator cuff tear trying to correlate these changes to their healing capability. METHODS: Eighty-four patients were clinically evaluated with the Constant Scale. Radiographs and MRI were performed preoperatively and ultrasound were performed postoperatively. For each patient, a biopsy of the supraspinatus tendon and subacromial bursa was performed, and the specimens were histopathologically analyzed. RESULTS: Tendons histopathological features consisted of loss of structural organization, poor or absent neoangiogenesis, chondral metaplasia, and fibrosis. Bursal features consisted of neoangiogenesis, absence of chondral metaplasia, hyperplasia/hypertrophy, and absence of necrosis. Direct correlation was seen between tendon and bursal hyperplasia and time of the onset of symptoms; between tendon chondral metaplasia, fibrosis, bursal neoangiogenesis, inflammation, and patient age; between tendon neoangiogenesis, hyperplasia, necrosis, fibrosis, bursal necrosis, inflammation, and lesion size; on the contrary, tendon fibrosis, necrosis, and bursal tissue inflammation decrease as time passes from the onset of symptoms. Tendon fibers disarray, neoangiogenesis, and inflammation decreases as the patient's age increases. Bursal tissue fibrosis decreases as lesion size increases. CONCLUSIONS: Simple histopathological techniques should be employed routinely to assess the tissue quality, with the aim to predict future clinical evolution (repair or non-repair). Comparing the histopathological data with the demographical information and the descriptive statistics, it is possible to define the RCT repair at risk and identify which RCT will be able to heal.

[Umbilical primary endometrioma. Case report]. / Endometriosi primitiva ombelicale. Caso clinico.

Umbilical primary endometrioma is a rare extra-uterine localization of endometriosis with a documented neoplastic risk. It is often difficult to distinguish primary umbilical endometriosis from other benign and malignant tumors of the abdominal wall. The Authors report a case of umbilical endometriosis in a 36-year old female. Endometriosis was suspected because of the presence of the typical cyclic bleeding and swelling. Abdominal CT excluded the presence of other endometriotic localizations. The umbilical mass was widely excised together with umbilicus, fascia and peritoneum. The tissue defect was primary closed without prosthetic mesh. Histological examination of the specimen showed the presence of endometrial glands with stromal component, compatible with the diagnosis of endometriosis. The Authors suggest that surgery should be performed in the first 3-4 days of the follicular phase, to minimize the risk of diffusion of endometriotic cells. Moreover, the excision should be wide in order to prevent local recurrence.

Spontaneous umbilical endometriosis: a case report with one-year follow-up.

Umbilical endometriosis is a very rare disease. We report a case of spontaneous umbilical endometriosis in a 36-year old female. Endometriosis was suspected because of the presence of the typical cyclic bleeding and swelling. Abdominal CT excluded the presence of other endometriotic localizations. The umbilical mass was widely excised together with the umbilicus, fascia and peritoneum. The ensuing defect was primarily closed without using prosthetic mesh. Postoperative recovery was uneventful. Histological examination of the specimen showed the presence of endometrial glands with a stromal component, compatible with the diagnosis of endometriosis. At one-year follow-up the results of surgery were satisfactory with no sign of endometriosis recurrence and or parietal defect occurrence. We suggest that surgical excision should be wide in order to prevent local recurrence, and prosthetic materials should not be used to repair the ensuing umbilical defect.

Atrial fibrillation in pure rheumatic mitral valvular disease is expression of an atrial histological change.

BACKGROUND: Some of theories try to explain the insurgence of atrial fibrillation (AF) in patients with acute articular rheumatism (AAR). These theories remind the close relation between AF and left atrium, or with valvular vitium degree, or monophasic action potential and histological cardiac structure. In 15 years of work in the academic Department of Heart and Big Vessels in Rome, the Authors studied 243 patients with mitral valvular disease post AAR before and after surgical manoeuvres. MATERIALS AND METHODS: Patients were divided in order to monitor atrium and ventricle morphological and functional modifications of the valve according to cardiac rhythm. Patients classification was based on surgical therapy adopted, kind of mitral disease and cardiac rhythm. An histological examination was performed, only in patients treated with valvular replacement. During the operation an histological examination in an atrial tissue fragment was performed. 243 patients with mitral valvular disease post AAR with indication in valvular adjustment were studied. The whole population was treated with mitral transcutaneous valvuloplasty (Group B--130 patients) or with mitral valve replacement surgery (Group A--113 patients). These two groups were divided: in Gr.A in Gr.A1 and Gr.A2, and Gr.B in Gr.B1 and Gr.B2, according to cardiac rhythm (sinus rhythm iSR, AF). These subgroups were also divided in Gr.A1SR, Gr.A1AF; Gr.A2SR, Gr.A2AF; Gr.A3SR, Gr.A3AF, according to mitralic disease's kind (stenosis, stenosis/regurgitation, regurgitation). A complex screening were exerted to all patients using echocardio-doppler technology. Morphological parameters of atrium and ventricle, and functional parameters of mitral valve, aorta and tricuspid were evaluated. In Gr.A group patients during the operation were execute a bioptic sampling from left atrium and a consecutive histological valuation. RESULTS: In Gr.A1 mitral valve area (MtVA) arises smaller (p<0.01) in the group with AF, than those in SR. On the contrary, in subgroups of population of Gr.B there isn't statistic disagreement (p>0.05). Left atrium volume arises elder in patients in AF than in patients in SR (p<0.01), either in patients of subgroups Gr.A1, Gr.A2 or in patients of the whole Gr.B before and after valvuloplasty. In the whole population Gr.B, either Gr.BRS or Gr.BFA, left and right atrial volumes decrease eloquently (p<0.01) after valvoplasty. There's no linear relationship (Pearson r<0.5) between the different subgroups of Gr.A (Gr.A1, Gr.A2, Gr.A3) and those of Gr.B according to mitral valve area (MtVA), volume and left atrial area. Left atrial biopsy shows in patients of SR a normal atrial tissue in the 48% of cases and lightly altered in remaining 52%. On the contrary in patients of AF there are strong anomalies in the 100% of cases. CONCLUSIONS: According to histological view, atrial volumes variations and valvular area variations before and after surgical treatment, and according also to their comparisons in different groups, authors could assume that insurgence of AF and its chronicization could be an expression of a strong atrial myocardial histological alteration. Furthermore while starting moment of AF genesis is characterized by histological alterations of atrial myocardium (expression of rheumatic chronic disease), its chronicization hands to anatomic-volumetric progressive deterioration of the atrial dysfunction.

Correlation of recurrence rates and times with posttreatment human papillomavirus status in patients treated with loop electrosurgical excision procedure conization for cervical squamous intraepithelial lesions.

The aim of the present study was to assess recurrence rates and times in patients with squamous intraepithelial lesion (SIL) of the uterine cervix treated with loop electrosurgical excision procedure (LEEP) conization, in order to define categories of patients who have a different risk of recurrence and who need a different surveillance protocol. This study was carried out on 119 consecutive patients who underwent LEEP. All patients were followed up with cervical smear and colposcopy after 3, 6, and 12 months in the first-year posttreatment, and every 6-12 months afterwards. Human papillomavirus (HPV) testing was performed at the time of LEEP and repeated 3-6 months later. The histologic examination of LEEP specimens revealed stage IA1 squamous cell cervical cancer in 4 (3.4%) cases, high-grade SIL in 75 (63%) cases, and low-grade SIL in 40 (33.6%) cases. The four patients with stage IA1 cervical cancer were not included in the further analyses. Disease recurred in none of the 50 patients with negative posttreatment HPV testing, in 4 (9.3%) of the 43 patients with positive posttreatment HPV testing and negative surgical margins, and in 8 (36.4%) of 22 patients with positive posttreatment HPV testing and positive margins. The combined evaluation of surgical margin status and posttreatment HPV testing could allow to subdivide patients treated with LEEP into categories at different risk of recurrence, requiring new tailored surveillance procedures.

Very low protein diet supplemented with ketoanalogs improves blood pressure control in chronic kidney disease.

Blood pressure (BP) is hardly controlled in chronic kidney disease (CKD). We compared the effect of very low protein diet (VLPD) supplemented with ketoanalogs of essential amino acids (0.35 g/kg/day), low protein diet (LPD, 0.60 g/kg/day), and free diet (FD) on BP in patients with CKD stages 4 and 5. Vegetable proteins were higher in VLPD (66%) than in LPD (48%). LPD was prescribed to 110 consecutive patients; after run-in, they were invited to start VLPD. Thirty subjects accepted; 57 decided to continue LPD; 23 refused either diet (FD group). At baseline, protein intake (g/kg/day) was 0.79+/-0.09 in VLPD, 0.78+/-0.11 in LPD, and 1.11+/-0.18 in FD (P<0.0001). After 6 months, protein intake was lower in VLPD than LPD and FD (0.54+/-0.11, 0.78+/-0.10, and 1.04+/-0.21 g/kg/day, respectively; P<0.0001). BP diminished only in VLPD, from 143+/-19/84+/-10 to 128+/-16/78+/-7 mm Hg (P<0.0001), despite reduction of antihypertensive drugs (from 2.6+/-1.1 to 1.8+/-1.2; P<0.001). Urinary urea excretion directly correlated with urinary sodium excretion, which diminished in VLPD (from 181+/-32 to 131+/-36 mEq/day; P<0.001). At multiple regression analysis (R2=0.270, P<0.0001), BP results independently related to urinary sodium excretion (P=0.023) and VLPD prescription (P=0.003), but not to the level of protein intake. Thus, in moderate to advanced CKD, VLPD has an antihypertensive effect likely due to reduction of salt intake, type of proteins, and ketoanalogs supplementation, independent of actual protein intake.

MMTV-like sequences in human breast cancer: a fluorescent PCR/laser microdissection approach.

The hypothesis that a retrovirus homologous to the mouse mammary tumour virus (MMTV) is involved in human breast cancer aetiology has fascinated scientists from many years, but it has never been convincingly demonstrated. Renewed interest in this hypothesis developed when an MMTV env gene-like sequence was found in 38% of human breast cancer tissues. Whereas some subsequent studies confirmed these findings, others did not. The main reasons for this discrepancy, among others, are the different sensitivities and technical details of current molecular approaches to the detection of these sequences. This study is an attempt to find sensitive and reproducible conditions capable of detecting MMTV env-like sequence in human samples. To this end, we first developed a fluorescence nested-PCR (FN-PCR) method that was able to detect very low copies of the viral genome, and then screened a panel of 45 frozen breast cancer samples obtained by laser microdissection. The MMTV env gene-like sequence was found in 15 (33%) of the human breast cancers analysed, whereas the same sequence was detectable neither in normal tissues nor in other types of tumour. Sequence analysis revealed 96% homology with the MMTV genome, but no other significant similarities with the human genome. The combined use of frozen material, microdissected cell populations and FN-PCR provides a novel, sensitive, robust, non-radioactive and fast methodology for the molecular detection of human-MTV. This approach might be successfully used in large molecular studies that aim to investigate the hypothesis of a retroviral aetiology of human breast cancer.

Cardiovascular risk factors in severe chronic renal failure: the role of dietary treatment.

BACKGROUND: Lipoprotein abnormalities and increased oxidized LDL (OxLDL) are often observed in uremia and are reported to play a central role in the development of cardiovascular disease (CVD). Vegan diet, known for its better lipoprotein profile and antioxidant vitamins content, could protect against CVD. Aim of this study was to investigate the influence of vegan diet supplemented with essential amino acids (EAA) and ketoanalogues (VSD) on both traditional and non-traditional cardiovascular risk factors (CVRF). METHODS: Twenty-nine patients (18 M, 11 F) aged 55 years (range 29-79 years) with advanced chronic renal failure (median sCr: 5.6 mg/dl) on very low protein vegetarian diet (0.3 g/kg/day) supplemented with a mixture of EAA and ketoacids (VSD) and 31 patients (20 M, 11 F) aged 65 years (range 29 - 82 years) on conventional low-protein diet (CD: 0.6 g/kg/day) with a similar renal function (median sCr: 5.2 mg/dl), were investigated for lipids and apolipoprotein parameters (traditional CVRF) as well as for oxidative stress (oxidized LDL, antibodies against OxLDL and thiobarbituric acid-reactive substances (TBARS)), total homocysteine (tHcy), lipoprotein(a) (Lp(a)), albumin and c-reactive protein (CRP) (non-traditional CVRF) including vitamins A, E, B12 and folic acid. RESULTS: Compared to patients on CD, those on VSD showed increased HDL cholesterol levels (p < 0.005) with a reduction of LDL cholesterol (p < 0.01) and an increase of apoA1/apoB ratio (p < 0.02). Among non-traditional CVRF, a mild but significant reduction of OxLDL (p < 0.05) with lower TBARS concentrations (p < 0.01) and a significant reduction of total homocysteine (p < 0.002), Lp(a) (p < 0.002) and CRP levels (p < 0.05) were also observed in these patients. Concentrations of vitamin E and A were not different between the two groups while vitamin B12 and folic acid resulted markedly increased in patients on VSD. OxLDL significantly correlated with total and LDL cholesterol, triglycerides and Apo B in CD but not in VSD patients. Patients on CD also showed a significant correlation between urea and CRP. After a multivariate analysis, only urea (p < 0.001) and OxLDL (p < 0.006) were associated to a risk of CRP > 0.3 mg/dl. CONCLUSIONS: These results indicate a better lipoprotein profile in patients on vegan diet including non-traditional CVRF. In particular, these patients show a reduced oxidative stress with a reduced acute-phase response (CRP) as compared to patients on conventional diet. We hypothesize that urea, significantly lower in patients on VSD, may account, possibly together with the reduction of other protein breakdown products, for the decreased acute-phase response observed in these patients. Our findings suggest that low-protein diets, and vegan in particular, may exert a beneficial effect on the development of cardiovascular disease in patients with end-stage renal disease (ESRD).

[Cystatin C, beta2-microglobulin and C-reactive protein in hemodiafiltration and on-line endogenous liquid reinfusion and in low flux polysulphone bicarbonate conventional hemodialysis]. / Cistatina C, beta2-microglobulina e proteina C-reattiva in emodiafiltrazione con reinfusione on-line (HFR) e in bicarbonato dialisi con polisulfone low-flux (BD).

PURPOSE: Dialysis morbidity results partly from middle and large molecule retention, which is poorly removed by conventional hemodialysis (HD). The potential benefit of convective treatments could be the enhanced toxin removal over a wide molecular weight spectrum. This study aimed to evaluate cystatin C (cis), beta2-microglobulin (beta2-m) and C-reactive protein (CRP) removal behavior during hemodiafiltration reinfusion vs conventional low-flux HD (1.8 m2 low-flux polysulphone) (bicarbonate dialysis (BD)). The molecular weights of the substances evaluated in this study were as follows: cis = 13,300 daltons, beta2-m = 11,818 daltons, CRP = 160,000 daltons. METHODS: Twelve patients on stable HD (six males, six females), were enrolled; six patients underwent BD and six patients underwent HFR. We measured arteriovenous serum cis, beta2-m and CRP levels, in three consecutive mid-week sessions at the following periods: pre/post-dialysis and after 60 min from the beginning of the session. At 60, 120 and 180 min of HFR, we collected the ultrafiltrate for cis, beta2-m, and CRP evaluation. RESULTS: Cis, beta2-m and CRP mean values did not differ at pre-dialysis in the two groups. Pre/post- dialysis difference for cis in HFR vs BD was statistically significant (p=0.002) because cis reduced in HFR and increased in BD during the session. Beta2-m and CRP pre/post- dialysis differences in HFR vs BD were not significant. Cis clearance, measured 60 min after the beginning of the session was 34.2 +/- 20.1 mL/min in HFR and 24.8 +/- 18.4 mL/min in BD (p<0.05). beta2-m and CRP clearances did not differ among the treatments. Regarding the ultrafitrate concentrations during the HFR session, cis significantly decreased (2.5 +/- 0.6 mg/dL at 60 min and 2.0 +/- 0.4 mg/dL at 180 min; p=0.004), as well as beta2-m (21.5 +/- 12.9 mg/dL and 19.0 +/- 14.1 mg/dL, respectively; p=0.02). Ultrafiltrate CRP values, as expected, did not differ during HFR. CONCLUSIONS: This study demonstrated that cis, a middle molecule, is well depurated in HFR, while in BD it increases. Beta2-m, although better removed in the convective phase during HFR, does not demonstrate a removal difference in HFR and in BD. CRP, a large molecule, does not have significant removal. Since cis and beta2-m have almost the same molecular weight, why do they have a different depuration? We need further studies to evaluate if membranes can remove these molecules or if protein electrical charges or their stereoscopy enables their removal.

Oxalate depuration during biofiltration with AN69 and in conventional hemodialysis in chronic renal failure (CRF) patients.

Oxalate (Ox), an end product of amino acid metabolism, accumulates in CRF patients as calcium crystal deposits in many soft tissues such as myocardium, kidney interstitium, etc. Since BF employs AN69, a high efficiency membrane, we tested its depurative efficacy for Ox against a hollow-fiber cuprophan dialyzer. Five CRF patients previously in HD and after six months of BF were studied. End-dialysis and pre-dialysis Ox values and dialyzer clearance were obtained. Predialysis Ox values were: 0.44 +/- 0.15 mg/dl in HD and 0.42 +/- 0.09 mg/dl in BF (NS). End-dialysis Ox values were: 0.30 +/- 0.09 mg/dl in HD and 0.22 +/- 0.04 mg/dl in BF (p less than 0.001). Pre and post dialysis values differed by 31% in HD and 47% in BF (p less than 0.001). Ox clearance was 98.8 +/- 10.3 ml/min in HD and 143 +/- 20.5 ml/min in BF. There was a rebound in Ox values at 48 hours (0.41 +/- 0.08 mg/dl in HD and 0.32 +/- 0.12 mg/dl in BF, (NS). These results indicate that Ox is depurated better during BF than during HD.

The role of metabolic acidosis in causing uremic hyperphosphatemia.

Metabolic acidosis was corrected within 1 h in 7 chronic anuric uremic patients on maintenance hemodialysis and, in the course of a week, in 11 other patients on conservative therapy. These patients were on a diet supplying constant amounts of phosphate throughout the duration of the study. In the former group the intravenous infusion of sodium bicarbonate was used, and, in the latter, the oral administration of sodium citrate. In both groups serum phosphate was found to decrease significantly. In the patients on conservative therapy, phosphaturia also had significantly decreased while no changes occurred in their daily fecal loss of phosphate that was measured in 3 patients. These findings indicate that metabolic acidosis is one of the causes of hyperphosphatemia in chronic uremic patients.