Variant-sequence transthyretin (isoleucine 122) in late-onset cardiac amyloidosis in black Americans

BACKGROUND

After the age of 60, isolated cardiac amyloidosis is four times more common among blacks than whites in the United States; 3.9 percent of blacks are heterozygous for an amyloidogenic allele of the normal serum carrier protein transthyretin in which isoleucine is substituted for valine at position 122 (Ile 122). We hypothesized that the high prevalence of transthyretin Ile 122 is at least partially responsible for the increased frequency of senile cardiac amyloidosis among blacks.

METHODS

Paraffin blocks of cardiac tissue were obtained from an earlier study of 52,370 autopsies in Los Angeles and were examined by immunohistochemical and DNA analyses. Samples were available from 32 of 55 blacks and 20 of 78 whites over 60 years of age with isolated cardiac amyloidosis and from two control groups (228 cases).

RESULTS

Transthyretin amyloidosis was identified in 31 of the 32 cardiac-tissue samples from the black patients and in 19 of the 20 samples from the white patients. Six of the 26 analyzable DNA samples (23 percent) from the black patients and none of the 19 samples from the white patients were heterozygous for the Ile 122 variant. Four of 125 DNA samples obtained at autopsy (3.2 percent) from a second, more recent, age-matched cohort of blacks without amyloidosis at the same institution were heterozygous for the transthyretin Ile 122 allele. On reexamination the cardiac tissue from these four patients contained small amounts of amyloid not detected at the initial autopsies. All subjects with the Ile 122 variant had ventricular amyloid.

CONCLUSIONS

The assessment of elderly black patients with unexplained heart disease should include a consideration of transthyretin amyloidosis, particularly that related to the Ile 122 allele.

Phytase activity in sourdough lactic acid bacteria: purification and characterization of a phytase from Lactobacillus sanfranciscensis CB1

The phytase activity of 12 species of sourdough lactic acid bacteria was screened. It was intracellular only, largely distributed among the species and strains of Lactobacillus sanfranciscensis possessed the highest levels of activity. A monomeric ca. 50-kDa phytase was purified to homogeneity from L. sanfranciscensis CB1 by three chromatographic steps. L. sanfranciscensis CB1 exhibited the highest hydrolysing activity on Na-phytate after reaching the stationary phase of growth (ca. 12 h). Cells cultivated in the presence of maltose and fructose showed an increase of the phytase activity of ca. 35% with respect to the other carbon sources used. The phytase was optimally active at pH 4.0 and 45 degrees C. The enzyme was strongly inhibited by 2 mM of phenylmethylsulfonyl fluoride (PMSF), and 2 mM Hg(2+) and Fe(2+). It had a pI of ca. 5.0. The substrate specificity was dependent on the type of phosphate ester; a very low activity was detected on alpha-D-glucose-1-phosphate and D-fructose-6- and 1,6-phosphate, while the highest hydrolysis was found towards adenosine-5'-tri-, di- and mono-phosphate. Compared to these substrates, the activity on Na-phytate was also relevant. The enzyme was thermo-stable after exposure to 70 degrees C for 30 min; the D value calculated at 80 degrees C was ca. 10 min. As shown by the Central Composite Design (CCD) applied to study the individual and interactive effects of pH, temperature and NaCl, acidic conditions and elevated temperatures were indispensable for the enzyme adaptation to high NaCl concentrations. L. sanfranciscensis CB1 cells or the correspondent cytoplasmic extract were used to ferment a sourdough for 8 h at 37 degrees C; a marked decreased (64-74%) of the Na-phytate concentration was found compared with the unstarted dough. The sourdough started with L. sanfranciscensis CB1 cells was re-used for several times and the phytase activity was maintained to a considerable level.

Biomarkers in Mytilus galloprovincialis exposed to suspensions of selected nanoparticles (Nano carbon black, C60 fullerene, Nano-TiO2, Nano-SiO2)

The potential for ecological toxicity associated with nanomaterials is a growing area of investigation, in particular in the aquatic environment. In suspension feeding invertebrates, the cellular immune system and digestive gland are likely to be targeted, due to their highly developed processes for the cellular internalisation of nano- and micro-scale particles that are integral to key physiological functions such as cellular immunity and intracellular digestion. We have recently demonstrated that suspensions of selected commercial nanomaterials, namely Nano carbon black (NCB), C60 fullerene (C60), Nano-titanium dioxide (n-TiO2) and Nanosilica (n-SiO2) induce oxyradical production and lysosomal enzyme release in the hemocytes of the marine mussel Mytilus in vitro. In this work the possible effects of in vivo exposure to these NPs were investigated. Mussels were exposed to different concentrations (0.05-0.2-1-5mg/l) of NP suspensions for 24h and different biomarkers were evaluated in hemocytes, digestive gland and gills. Characterisation of NP suspensions in artificial sea water (ASW) was performed, indicating the formation of agglomerates of different sizes in the nano-micromolar range for different types of NPs. Formation of larger agglomerates was observed at the end of exposure. The results show that all NP suspensions induced significant lysosomal membrane destabilisation in both the hemocytes and the digestive gland, with NCB>>C60>n-TiO2, >n-SiO2. In the digestive gland, all NPs induced lysosomal lipofuscin accumulation only at the highest concentrations tested to a different extent depending on the NP type. NCB, TiO2 and SiO2 also induced lysosomal neutral lipid accumulation. Moreover, all NPs increased the activity of the antioxidant enzyme catalase, with n-SiO2>NCB≅TiO2>C60; NCB and n-TiO2 also stimulated glutathione transferase (GST). Changes in catalase and GST activities were also observed in gills, with both increases and decreases depending on NP type and concentration. The reported results demonstrate that in mussels responses to exposure to NP suspensions involve changes in lysosomal and oxidative stress biomarkers in the digestive gland, suggesting uptake of NP aggregates/agglomerates mainly through the digestive system. Overall, these data further support the hypothesis that suspension feeding invertebrates represent a significant target for NPs in the aquatic environment.

Studies of the mechanisms of action of the antiretroviral agents hypericin and pseudohypericin

Administration of the aromatic polycyclic dione compounds hypericin or pseudohypericin to experimental animals provides protection from disease induced by retroviruses that give rise to acute, as well as slowly progressive, diseases. For example, survival from Friend virus-induced leukemia is significantly prolonged by both compounds, with hypericin showing the greater potency. Viremia induced by LP-BM5 murine immunodeficiency virus is markedly suppressed after infrequent dosage of either substance. These compounds affect the retroviral infection and replication cycle at least at two different points: (i) Assembly or processing of intact virions from infected cells was shown to be affected by hypericin. Electron microscopy of hypericin-treated, virus-producing cells revealed the production of particles containing immature or abnormally assembled cores, suggesting the compounds may interfere with processing of gag-encoded precursor polyproteins. The released virions contain no detectable activity of reverse transcriptase. (ii) Hypericin and pseudohypericin also directly inactivate mature and properly assembled retroviruses as determined by assays for reverse transcriptase and infectivity. Accumulating data from our laboratories suggest that these compounds inhibit retroviruses by unconventional mechanisms and that the potential therapeutic value of hypericin and pseudohypericin should be explored in diseases such as AIDS.

Endothelial Dysfunction in Hypertension: Current Concepts and Clinical Implications

Endothelium plays a fundamental role in the cardiovascular system, forming an interface between blood and adjacent tissues by regulating the vascular tone through the synthesis of nitric oxide, prostaglandins and other relaxing factors. Endothelial dysfunction is characterized by vasoconstriction, cell proliferation and shifting toward a proinflammatory and prothrombic state. In hypertension endothelial dysfunction may be involved in the initiation and development of vascular inflammation, vascular remodeling, and atherosclerosis and is independently associated with increased cardiovascular risk. Different conditions such as impaired vascular shear stress, inflammation and oxidative stress, activation of the renin angiotensin system have been described as important pathophysiological mechanisms involved in the development of endothelial dysfunction. The release of extracellular vesicles by neighboring cells in the vascular wall has emerged as an important regulator of endothelial function and with potential antihypertensive properties and beneficial effects by counteracting the hypertension mediated organ damage. Furthermore, macrovesicles are emerging as an innovative therapeutic approach for vascular protection, allowing the delivery of bioactive molecules, such as miRNA and drugs interacting with the renin angiotensin system. In this review we summarize the available evidence about the pathophysiological implications of endothelial dysfunction in cardiovascular diseases, focusing on hypertension and its sequelae, and the potential innovative therapeutic strategies targeting the endothelium with the aim to improve vascular function and remodeling.

Coronavirus pandemic and colorectal surgery: practical advice based on the Italian experience

AIM

The current COVID-19 pandemic is challenging healthcare systems at a global level. We provide a practical strategy to reorganize pathways of emergency and elective colorectal surgery during the COVID-19 pandemic.

METHOD

The authors, all from areas affected by the COVID-19 emergency, brainstormed remotely to define the key-points to be discussed. Tasks were assigned, concerning specific aspects of colorectal surgery during the pandemic, including the administrative management of the crisis in Italy. The recommendations (based on experience and on the limited evidence available) were collated and summarized.

RESULTS

Little is known about the transmission of COVID-19, but it has shown a rapid spread. It is prudent to stop non-cancer procedures and prioritize urgent cancer treatment. Endoscopy and proctological procedures should be performed highly selectively. When dealing with colorectal emergencies, a conservative approach is advised. Specific procedures should be followed when operating on COVID-19-patients, using dedicated personal protective equipment and adhering to specific rules. Some policies are described, including minimally-invasive surgery. These policies outline the strict regulation of entry/ exit into theatres and operating building as well as advice on performing procedures safely to reduce risk of spreading the virus. It is likely that a reorganization of health system is required, both at central and local levels. A description of the strategy adopted in Italy is provided.

CONCLUSION

Evidence on the management of patients needing surgery for colorectal conditions during the COVID-19 pandemic is currently lacking. Lessons learnt from healthcare professionals that have managed high volumes of surgical patients during the pandemic could be useful to mitigate some risks and reduce exposure to other patients, public and healthcare staff.

Consensus statement of the Italian society of colorectal surgery (SICCR): management and treatment of hemorrhoidal disease

Hemorrhoidal disease (HD) is the most common proctological disease in the Western countries. However, its real prevalence is underestimated due to the frequent self-medication.The aim of this consensus statement is to provide evidence-based data to allow an individualized and appropriate management and treatment of HD. The strategy used to search for evidence was based on application of electronic sources such as MEDLINE, PubMed, Cochrane Review Library, CINAHL, and EMBASE.These guidelines are inclusive and not prescriptive.The recommendations were defined and graded based on the current levels of evidence and in accordance with the criteria adopted by American College of Chest Physicians. The recommendations were graded A, B, and C.

Codeposition of cystatin C with amyloid-beta protein in the brain of Alzheimer disease patients

Immunohistochemical analysis of brains of patients with Alzheimer disease (AD) revealed that the cysteine proteinase inhibitor cystatin C colocalizes with amyloid beta-protein (Abeta) in parenchymal and vascular amyloid deposits. No evidence of cerebral hemorrhage was observed in any of the brains studied. Immunoelectron microscopy demonstrated dual staining of amyloid fibrils with anti-Abeta and anti-cystatin C antibodies. Cystatin C immunoreactivity was also observed in amyloid deposits in the brain of transgenic mice overexpressing human beta amyloid precursor protein. Massive deposition of the variant cystatin C in the cerebral vessels of patients with the Icelandic form of hereditary cerebral hemorrhage with amyloidosis is thought to be responsible for the pathological processes leading to stroke. Anti-cystatin C antibodies strongly labeled pyramidal neurons within cortical layers most prone to amyloid deposition in the brains of AD patients. Immunohistochemistry with antibodies against the carboxyl-terminus of Abeta(x-42) showed intracellular immunoreactivity in the same neuronal subpopulation. It remains to be established whether the association of cystatin C to Abeta plays a primary role in amyloidogenesis of AD or is a late event in which the protein is bound to the previously formed Abeta amyloid fibrils.

Nonamyloidotic monoclonal immunoglobulin deposition disease. Light-chain, heavy-chain, and light- and heavy-chain deposition diseases

In 1990 and 1992, in previous reviews of the literature and in reports of their experience with both amyloid and non-amyloid monoclonal immunoglobulin deposition diseases, the authors proposed a classification scheme encompassing all the forms of non-antibody-mediated monoclonal immunoglobulin deposition. The premise underlying the proposal was that the mode of pathogenesis of each of the various disorders is similar. Monoclonal expansion of a B-cell and plasma-cell population producing an excess immunoglobulin polypeptide with structural characteristics predisposing to tissue deposition in either the fibrillar or nonfibrillar state would be associated with organ-compromising deposits in tissue. At that time it appeared that LCDD and LHCDD were more likely to occur in the course of myeloma in which the other features of the neoplastic cells (i.e., marrow suppression, lytic lesions, recurrent infections) were also clearly evident. At this time, the authors' additional experience suggests that this judgment may have been premature, based in part on too small an initial sample and in part on the use of diagnostic criteria for multiple myeloma that may have not been sufficiently precise. The authors now believe that the nodular glomerulopathic form of NAMIDD is similar in both course and prognosis to AL amyloidosis occurring in the absence of multiple myeloma (primary amyloidosis). The primarily tubular basement-membrane form of the disease usually seen with concurrent myeloma kidney with BJCN, is associated with more aggressively proliferative plasma-cell neoplasms. The authors believe that these associations relate to the size of the malignant clone which, in turn, determines the amount of depositionogenic protein available and the rate of its presentation to the target organ (primarily the kidney). The distinction is not trivial, for if the authors are correct, their data suggest that not all forms of renal disease occurring in the course of plasma-cell dyscrasias have the same bleak prognosis. The outlook for nodular glomerular disease, as an indirect marker of clone size, may be intrinsically better than that of a renal biopsy showing cast nephropathy and tubular basement membrane LCDD deposits and clinical renal failure. Since 1992, it has also become less certain that there are general structural differences between light chains forming amyloid and those producing non-Congophilic tissue deposits. The current data suggest that light-chain proteins with the capacity to form pathogenic tissue deposits may exist in a spectrum, with one end represented by those only capable of forming amylord, the other by those depositing in a more amorphous, nonfibrillar manner, and a group in the center capable of either or both, depending on circumstances that are presently not understood. An alternative view suggests that all or most proteins depositing as fibrils pass through a non-Congophilic, nonfibrillar phase, of a length varying according to their primary structure, which is not detected in vivo because of the vagaries imposed by clinical sampling. More structural analyses of material extracted from deposits in tissue may resolve this issue.

Renal hemodynamic response to maximal vasodilating stimulus in healthy older subjects

BACKGROUND

It is still unclear whether age per se is associated with preservation of renal functional reserve, that is, of the increase in glomerular filtration rate (GFR) induced by appropriate vasodilating stimulus.

METHODS

To gain insights into this issue, we evaluated the renal response to a maximal vasodilating stimulus, represented by the combined infusion of mixed amino acid solution (AA) and dopamine at renal dose (D), in 10 young subjects (median age of 30 years, range of 19 to 32) and in 11 subjects of older age (median age of 67 years, range of 65 to 76). Two further age-matched groups of young (N = 15) and older (N = 11) living kidney donors underwent renal needle biopsy immediately before nephrectomy to perform semiquantitative scoring (0 to 3) of arteriosclerosis in intrarenal arteries. All of the study subjects were nonsmokers with healthy status proven by extensive diagnostic evaluation excluding any risk factor of renal dysfunction.

RESULTS

Basal renal plasma flow (RPF) and GFR were proportionally lower in older subjects (RPF, 361 +/- 29 vs. 618 +/- 34 mL/min/1.73 m(2), P < 0.001; GFR, 79 +/- 4 vs. 127 +/- 5.8 mL/min/1.73 m(2), P < 0.001). After AA + D, a significant increase of RPF and GFR was observed in both groups, but the older subjects exhibited a smaller percentage increment (RPF, 25.5 +/- 4.8 vs. 42.4 +/- 5.8, P < 0.05; GFR, 19.6 +/- 5.7 vs. + 33.8 +/- 6.4, P < 0.05). Furthermore, the maximal vasodilating stimulus was not able to restore renal hemodynamics in older subjects to the level measured in young controls at baseline. Renal vascular resistances were higher (P < 0.05) in the older subjects both at baseline (0.19 +/- 0.02 vs. 0.09 +/- 0.004 mm Hg/mL/min) and after AA + D (0.14 +/- 0.01 vs. 0.06 +/- 0.004). Light microscopy examination detected the presence of a greater degree of arteriosclerosis at the level of interlobular and arcuate arteries (0.89 +/- 0.15 vs. 0.45 +/- 0.08) and interstitial fibrosis/tubular atrophy (1.18 +/- 0.13 vs. 0.53 +/- 0.13) in older than in young subjects.

CONCLUSIONS

Therefore, aging has adverse effects on renal function despite the absence of any risk factor for renal disease, including chronic smoking: (1) GFR and RPF are lower, and (2) the renal response to maximal vasodilating stimulus is impaired. These aging-related alterations of renal hemodynamics are possibly due to organic lesions in renal vasculature.

A head-to-head comparison of ixekizumab vs. guselkumab in patients with moderate-to-severe plaque psoriasis: 12-week efficacy, safety and speed of response from a randomized, double-blinded trial

BACKGROUND

Patients with psoriasis value rapid and complete skin clearance. No head-to-head studies have focused on early responses to interleukin (IL)-17 vs. IL-23 inhibitors.

OBJECTIVES

To compare early and complete skin clearance by the IL-17A inhibitor ixekizumab vs. the IL-23p19 inhibitor guselkumab.

METHODS

IXORA-R, a 24-week, randomized, double-blinded study, enrolled adults with moderate-to-severe plaque psoriasis [static Physician's Global Assessment of Disease (sPGA) score of ≥ 3, Psoriasis Area and Severity Index (PASI) ≥ 12, and ≥ 10% body surface area]. Patients were randomized (1 : 1) to receive the approved dose of subcutaneous ixekizumab or guselkumab. Primary end point was 100% improvement in PASI (PASI 100) at week 12. Major secondary end points included other levels of improved PASI and sPGA at different time points. Comparisons were made using the Cochran-Mantel-Haenszel test with a multiple testing strategy. Nonresponder imputation was used for missing data. After the completion of the study, the final secondary end point (PASI 100 at 24 weeks) and safety data through week 24 will be reported.

RESULTS

In total, 1027 patients were randomized. The primary end point PASI 100 at week 12 was met [215/520 ixekizumab (41%); 126/507 guselkumab (25%); P < 0·001]. All major secondary end points measured up to week 12 were met, including PASI 50 at week 1 and PASI 75 at week 2. Serious adverse event frequency was 3% for each group; no new safety signals were identified.

CONCLUSIONS

Ixekizumab was superior to guselkumab for rapidly improving signs and symptoms in patients with moderate-to-severe plaque psoriasis by week 12. Adverse events were similar to previous ixekizumab and guselkumab studies. Compared with the IL-23 inhibitor guselkumab, ixekizumab can offer complete skin clearance more rapidly to patients with moderate-to-severe plaque psoriasis. What's already known about this topic? Patients with plaque psoriasis desire both high levels of clearance and rapid onset of treatment effects. Ixekizumab, a high-affinity monoclonal antibody that selectively targets interleukin (IL)-17A, has demonstrated greater and faster skin clearance than etanercept and ustekinumab, with consistent long-term efficacy, safety and durability of response. Clinical trial data and systematic reviews have suggested that IL-17 inhibitors can improve a patient's psoriasis more rapidly than IL-23 inhibitors. What does this study add? The head-to-head study design directly compares the efficacy and speed of response of ixekizumab and the IL-23 inhibitor guselkumab in moderate-to-severe plaque psoriasis. The primary end point was met, showing superiority of ixekizumab over guselkumab for achieving complete skin clearance at week 12. The safety profile of ixekizumab was consistent with previous studies. Ixekizumab can deliver patients complete skin clearance and improved quality of life more rapidly than guselkumab.

Risk of parenterally transmitted hepatitis following exposure to surgery or other invasive procedures: results from the hepatitis surveillance system in Italy

BACKGROUND/AIMS

To evaluate the strength of association between parenterally transmitted viral hepatitis and specific types of invasive procedures.

METHODS

Data from the surveillance system for type-specific acute viral hepatitis (SEIEVA) during the period 1994-1999 were used. The association of acute hepatitis B virus (HBV) and hepatitis C virus (HCV) infection with the potential risk factors (odds ratios (OR)) was estimated comparing 3120 hepatitis B and 1023 hepatitis C cases with 7158 hepatitis A cases, used as controls, by multiple logistic regression analysis.

RESULTS

Most procedures resulted in being associated with the risk of acquiring acute HBV or HCV. The strongest associations were: for HBV infection, abdominal surgery (adjusted OR = 3.9; 95% confidence intervals (CI) = 2.0-7.5), oral surgery (OR = 2.7; 95% CI = 1.6-4.5) and gynaecological surgery (OR = 2.6; 95% CI = 1.2-5.5); for HCV infection, obstetric/gynaecological interventions (OR = 12.1; 95% CI = 5.6-26.3), abdominal surgery (OR = 7.0; 95% CI = 3.2-14.9) and ophthalmological surgery (OR = 5.2; 95% CI = 1.1-23.2). Biopsy and/or endoscopy were associated with HCV, but not with HBV infection.

CONCLUSIONS

Invasive procedures represent an important mode of HBV and HCV transmission. Since a large proportion of the adult general population is exposed to these procedures and an effective HCV vaccine is not yet available, non-immunological means of controlling iatrogenic modes of transmission are extremely important.

The impact of the hepatitis B mass immunisation campaign on the incidence and risk factors of acute hepatitis B in Italy

BACKGROUND/AIMS

This study aimed to evaluate the impact of the campaign for hepatitis B mass immunisation of children and teenagers, introduced in 1991, on the incidence of and risk factors for hepatitis B in Italy.

METHODS

Hepatitis B cases reported to the surveillance system for type-specific acute viral hepatitis (SEIEVA) during the period 1987-1997 were used to estimate incidence. To assess the association between potential risk factors and hepatitis B cases, hepatitis A cases generated by the same surveillance system were used as controls.

RESULTS

During the period 1987-1997, 8275 acute hepatitis B cases were reported to SEIEVA. Hepatitis B incidence declined from 10.4/100,000 in 1987 to 2.9/100,000 in 1997. The fall was more evident before than after the introduction of compulsory vaccination against hepatitis B. The results of multivariate analysis showed that during the years 1995-1997, blood transfusion, intravenous drug use, surgical intervention, dental therapy, other parenteral exposures, multiple sexual partners, and being in the household of a chronic HBsAg carrier were all exposures independently associated with hepatitis B.

CONCLUSIONS

The strong association linking acute hepatitis B with iatrogenic exposures, which are more common in adults, suggests that the present immunisation strategy should be combined with the implementation of non-immunologic preventive measures.

Novel 7-oxyiminomethyl derivatives of camptothecin with potent in vitro and in vivo antitumor activity

In an attempt to synthesize potential anticancer agents acting by inhibition of topoisomerase I (Topo I) a new series of oxyiminomethyl derivatives in position 7 of camptothecin (CPT) was prepared. The synthesis relied on the condensation of 20S-CPT-7-aldehyde or 20S-CPT-7-ketones with alkyl, aryl, heteroaryl, arylalkyl, and heteroarylalkyl O-substituted hydroxylamines. The compounds were tested for their cytotoxic activity in vitro against H460 non-small lung carcinoma cell line, the activity being for 24 out of 37 compounds in the 0.01-0.3 microM range. A QSAR analysis indicated that lipophilicity is the main parameter correlated with cytotoxicity. Investigation of the DNA-Topo I-drug cleavable complex showed a rough parallelism between cytotoxicity and inhibition of Topo I. Persistence of the DNA cleavage after NaCl-mediated disruption of the ternary complex suggests that for the most potent compounds, e.g., 15, the cytotoxicity was at least in part related to stabilization of the complex, as also supported by the persistence of the DNA-enzyme complex in drug-treated cells. The in vivo antitumor efficacy of the most potent analogue (15) was evaluated in direct comparison with topotecan using human lung tumor xenograft models. In the range of optimal doses (2-3 mg/kg), the improved efficacy of 15 was documented in terms of inhibition of tumor growth and rate of complete response.

Molecular and functional characterization of Lactobacillus sanfranciscensis strains isolated from sourdoughs

Fifty isolates of Lactobacillus sanfranciscensis from Italian sourdoughs were identified and typed by a polyphasic approach which included genotypic and phenotypic criteria. Genotypic diversity was characterized by Ribosomal Intergenic Spacer Analysis (RISA) of PCR amplified 16S-23S rDNA spacer region, denaturing gradient gel electrophoresis (DGGE) of PCR amplified rpoB (beta subunit of RNA polymerase) gene, and rep-PCR (PCR amplification of repetitive bacterial DNA elements) analyses. The RISA analysis produced a unique electrophoretical profile of four bands (ranging from 300 to 600 bp) for all L. sanfranciscensis isolates. The DGGE analysis of rpoB gene allowed the subdivision of isolates in four clusters. The resolution found by using rep-PCR with primers BOXA1R and REP1R-I/REP2-I allowed the widening of the level of isolates heterogeneity. Phenotypic diversity was evaluated by Biolog System and characterization of several technological traits (e.g., acidification kinetics, proteinase and peptidase activities). L. sanfranciscensis isolates used a large varieties of carbon sources such as dextrin, D-fructose, L-fucose, alpha-D-glucose, maltose, palatinose, L-rhanmose, L- and D,L-lactic acids and L-methionine. The acidification activity and related quotient of fermentation, and the peptidase (PepN, PepV, PepT, PepI, PepX, PepQ and PepR) activities markedly varied among strains. The same was found concerning the capacity to liberate amino acids during sourdough fermentation. This study could be considered as an example of a computerized analysis of the genotypic and phenotypic traits to reliably and rapidly differentiate sourdough isolates. Although some L. sanfranciscensis isolates combined several technological traits, the association of more selected strains seemed to be a requisite to get optimal sourdough characteristics.

Immune complex glomerulonephritis in patients coinfected with human immunodeficiency virus and hepatitis C virus

Human immunodeficiency virus-associated nephropathy (HIVAN), characterized by heavy proteinuria, rapidly progressive renal failure, "collapsing" glomerulopathy, and tubulointerstitial abnormalities, is the most common finding in HIV-infected patients undergoing a renal biopsy and predominantly affects blacks. We describe the clinical features and renal pathologic findings of 12 intravenous drug users (IVDUs) coinfected with HIV and hepatitis C virus (HCV) who were selected for renal biopsy because they presented with features different from typical HIVAN, including hypertension, microscopic hematuria, and cryoglobulinemia. There were seven black and five Hispanic patients. Eleven patients had immune complex glomerulonephritis (ICGN); one had glomerulosclerosis with immune complex deposits. Ten individuals had evidence of past hepatitis B viral infection, but none had persistent hepatitis B surface antigenemia. No other underlying cause for immune complex glomerulonephritis was identified. Renal biopsy showed membranoproliferative glomerulonephritis in five patients, mesangial proliferative glomerulonephritis in five, membranous nephropathy in one, and "collapsing" glomerulopathy with immune complex deposits in one. Hepatitis C virus RNA was detected by reverse transcription-polymerase chain reaction (RT-PCR) in the renal tissue and/or serum of nine of the 11 patients tested, and also in the renal biopsy tissue of four of eight patients with clinical and pathologic features of typical HIVAN without immunofluorescence evidence of immune complex deposits. One patient presented with renal failure, five patients developed end-stage renal disease (ESRD) requiring hemodialysis (mean time, 6.5 months), and six had stable renal function after a mean follow-up of 29.1 months (range, 2 to 72 months). Liver function abnormalities were present in seven of the 12 individuals, including four of the six patients who developed renal failure. These findings indicate that in some patients coinfected with HIV and HCV, the development of ICGN may dominate the clinical course of the disease. The occurrence of ICGN among black patients at risk for HIVAN may be related to the relatively high prevalence of HCV infection among IVDUs in this group.

Amyloid and nonfibrillar deposits in mice transgenic for wild-type human transthyretin: a possible model for senile systemic amyloidosis

The human serum protein transthyretin (TTR) is highly fibrillogenic in vitro and is the fibril precursor in both autosomal dominant (familial amyloidotic polyneuropathy [FAP] and familial amyloidotic cardiomyopathy [FAC]) and sporadic (senile systemic amyloidosis [SSA]) forms of human cardiac amyloidosis. We have produced mouse strains transgenic for either wild-type or mutant (TTRLeu55Pro) human TTR genes. Eighty-four percent of C57BI/6xDBA/2 mice older than 18 months, transgenic for the wild-type human TTR gene, develop TTR deposits that occur primarily in heart and kidney. In most of the animals, the deposits are nonfibrillar and non-Congophilic, but 20% of animals older than 18 months that bear the transgene have human TTR cardiac amyloid deposits identical to the lesions seen in SSA. Amino terminal amino acid sequence analysis and mass spectrometry of the major component extracted from amyloid and nonamyloid deposits revealed that both were intact human TTR monomers with no evidence of proteolysis or codeposition of murine TTR. This is the first instance in which the proteins from amyloid and nonfibrillar deposits in the same or syngeneic animals have been shown to be identical by sequence analysis. It is also the first time in any form of amyloidosis that nonfibrillar deposits have been shown to systematically occur temporally before the appearance of fibrils derived from the same precursor in the same tissues. These findings suggest, but do not prove, that the nonamyloid deposits represent a precursor of the fibril. The differences in the ultrastructure and binding properties of the deposits, despite the identical sizes and amino terminal amino acid sequences of the TTR and the dissociation of deposition and fibril formation, provide evidence that in vivo factors, perhaps associated with aging, impact on both systemic precursor deposition and amyloid fibril formation.