Seasonal Controls on Microbial Depolymerization and Oxidation of Organic Matter in Floodplain Soils.

Floodplain soils are vast reservoirs of organic carbon often attributed to anaerobic conditions that impose metabolic constraints on organic matter degradation. What remains elusive is how such metabolic constraints respond to dynamic flooding and drainage cycles characteristic of floodplain soils. Here we show that microbial depolymerization and respiration of organic compounds, two rate-limiting steps in decomposition, vary spatially and temporally with seasonal flooding of mountainous floodplain soils (Gothic, Colorado, USA). Combining metabolomics and -proteomics, we found a lower abundance of oxidative enzymes during flooding coincided with the accumulation of aromatic, high-molecular weight compounds, particularly in surface soils. In subsurface soils, we found that a lower oxidation state of carbon coincided with a greater abundance of chemically reduced, energetically less favorable low-molecular weight metabolites, irrespective of flooding condition. Our results suggest that seasonal flooding temporarily constrains oxidative depolymerization of larger, potentially plant-derived compounds in surface soils; in contrast, energetic constraints on microbial respiration persist in more reducing subsurface soils regardless of flooding. Our work underscores that the potential vulnerability of these distinct anaerobic carbon storage mechanisms to changing flooding dynamics should be considered, particularly as climate change shifts both the frequency and extent of flooding in floodplains globally.

[Recessive dystrophic epidermolysis bullosa (Hallopeau-Siemens) with IgA nephropathy: 4 cases]. / Epidermolyse bulleuse dystrophique récessive d'Hallopeau-Siemens associée à une glomérulonéphrite à dépôts mésangiaux d'IgA: 4 cas.

BACKGROUND: The Hallopeau-Siemens type of recessive dystrophic epidermolysis bullosa (HS-RDEB) is a severe hereditary dermatosis, associated with a collagen VII deficiency. A chronic inflammatory syndrome, secondary to recurrent cutaneous infections, may be the cause of AA amyloidosis, with chronic renal failure, involving life prognosis. Less frequently, an IgA glomerulonephritis may occur and induce renal failure. Only two cases have been previously described. We report herein four new cases. CASE REPORT: We report four cases of HS-RDEB associated with IgA glomerulonephritis. A renal biopsy confirmed the diagnosis in all four cases. Later on, two patients had a second renal biopsy, indicated for deterioration of renal function. One of these patients showed AA type renal amyloidosis on the second biopsy. None of these six biopsies, conducted in our four patients led to local cutaneous complications. Subsequently three patients presented with terminal renal failure. Hemodialysis was set up, with good tolerance and improvement in quality of life. DISCUSSION: IgA glomerulonephritis should be suspected if a patient with HS-RDEB presents with hematuria. Renal biopsy is not contraindicated, confirms the diagnosis and helps to specify the prognosis. Hemodialysis is possible and well tolerated in the terminal stage of renal failure. There is not enough evidence for a genetic link between HS-RDEB and IgA glomerulonephritis, but repeated skin infections may be involved in the pathophysiology of the renal disease.

Gene expression in sheep skin and wool (hair).

We sequenced 2939 ESTs from fetal and adult sheep skin. Stages of gestation were picked to coincide with the major events in skin appendage (wool follicle) formation. Clustering analysis generated a nonredundant set of ESTs 2435 strong (83% nonredundant). Approximately 24% of these gave no hit to NCBI build 29 of the human genome, while 35% were tentatively classified by putative function based on BLASTX hits with a p(N) of <10(-4). In addition to bioinformatics analysis of our ESTs and gene mapping, we have generated a large EST spatial expression data set using in situ hybridization. One thousand one hundred forty-two ESTs have been used for in situ localization; about 31% are from adult sheep skin, 39% from late gestation fetal sheep skin, and 30% from midgestation fetal sheep skin. These probes have been used in over 3000 hybridization experiments. In this report, we summarize the results of in situs on adult sheep skin.

Characterization of mouse Frizzled-3 expression in hair follicle development and identification of the human homolog in keratinocytes.

Frizzled genes encode a family of Wnt ligand receptors, which have a conserved cysteine-rich Wnt binding domain and include both transmembrane and secreted forms. Work by others has shown that experimental perturbation of Wnt signaling results in aberrant hair formation, hair growth, and hair structure. To date, however, there is no information on the contribution of individual Frizzled proteins to hair development. We now report that Frizzled-3 expression in skin is restricted to the epidermis and to the developing hair follicle. Northern analysis on total mouse skin mRNA revealed a single Frizzled-3 transcript of 3.7 kb. Reverse transcription-polymerase chain reaction and in situ hybridization analysis revealed Frizzled-3 expression in epidermal and hair follicle keratinocytes. Frizzled-3 transcripts are first detected in discrete foci in the developing epidermis of 13 d embryos and later in the hair follicle placodes of 15 d embryos, suggesting a role for this Frizzled isoform in follicle development. In 17 d embryos and 1 d old newborn mice Frizzled-3 expression is limited to suprabasal keratinocytes and is not seen in pelage follicles until 3 d postpartum. In 7 d old neonatal skin, Frizzled-3 is expressed throughout the epidermis and in the outer cell layers of hair follicles. We have also identified the mRNA encoding human Frizzled-3 in epidermal keratinocytes and in the HaCaT keratinocyte cell line. Human Frizzled-3 mRNA encodes a 666 amino acid protein with 97.8% identity to the mouse protein. The human Frizzled-3 gene was mapped using a radiation-hybrid cell line panel to the short arm of chromosome 8 between the markers WI-1172 and WI-8496 near the loci for the Hypotrichosis of Marie Unna and Hairless genes.

Analysis of mouse keratin 6a regulatory sequences in transgenic mice reveals constitutive, tissue-specific expression by a keratin 6a minigene.

The analysis of keratin 6 expression is complicated by the presence of multiple isoforms that are expressed constitutively in a number of internal stratified epithelia, in palmoplantar epidermis, and in the companion cell layer of the hair follicle. In addition, keratin 6 expression is inducible in interfollicular epidermis and the outer root sheath of the follicle, in response to wounding stimuli, phorbol esters, or retinoic acid. In order to establish the critical regions involved in the regulation of keratin 6a (the dominant isoform in mice), we generated transgenic mice with two different-sized mouse keratin 6a constructs containing either 1.3 kb or 0.12 kb of 5' flanking sequence linked to the lacZ reporter gene. Both constructs also contained the first intron and the 3' flanking sequence of mouse keratin 6a. Ectopic expression of either transgene was not observed. Double-label immunofluorescence analyses demonstrated expression of the reporter gene in keratin 6 expressing tissues, including the hair follicle, tongue, footpad, and nail bed, showing that both transgenes retained keratinocyte-specific expression. Quantitative analysis of beta-galactosidase activity verified that both the 1.3 and 0.12 kb keratin 6a promoter constructs produced similar levels of the reporter. Notably, both constructs were constitutively expressed in the outer root sheath and interfollicular epidermis in the absence of any activating stimulus, suggesting that they lack the regulatory elements that normally silence transcription in these cells. This study has revealed that a keratin 6a minigene contains critical cis elements that mediate tissue-specific expression and that the elements regulating keratin 6 induction lie distal to the 1.3 kb promoter region.

Large-scale analysis of differential gene expression in the hindlimb muscles and diaphragm of mdx mouse.

The mdx mouse is an animal model for Duchenne muscular dystrophy (DMD), which is caused by the absence of dystrophin. Mdx limb muscles substantially compensate for the lack of dystrophin while the diaphragm is affected like DMD skeletal muscles. To understand better the complex cascade of molecular events leading to muscle degeneration and compensatory processes in mdx muscles, we analyzed alterations of gene expression in mdx hindlimb and diaphragm muscles as compared to their normal counterparts. The strategy was based on suppression subtractive hybridization followed by reverse Northern quantitative hybridization. Four subtracted/normalized libraries, containing cDNA clones up- or downregulated in mdx hindlimb muscles or diaphragm, were constructed and a total of 1536 cDNA clones were analyzed. Ninety-three cDNAs were found to be differentially expressed in mdx hindlimb muscles and/or diaphragm. They corresponded to 54 known genes and 39 novel cDNAs. The potential role of the known genes is discussed in the context of the mdx phenotype.

Evidence for developmentally regulated transcriptional, translational and post-translational control of metallothionein gene expression in hair follicles.

The distribution of metallothionein (MT) and MT mRNAs was examined in hair (wool) follicles, where high levels of cell proliferation are found and where the resulting cells provide a temporal record of differentiation events. MT was found in the cytoplasm and some nuclei of follicle bulb cells of the proliferative zone, outer root sheath cells and in basal layer cells of sebaceous glands and sweat glands. The population of 5-bromo-2'-deoxyuridine (BrdU)+ cells in these tissues overlapped, but were not completely coincident with the distribution of MT staining. MT mRNA expression in hair (wool) follicles was assessed by in situ hybridization with four gene-specific sheep MT (sMT) isoforms. Intense signals were obtained with the sMT-Ib probe in follicle bulb cells from the proliferative zone to the keratogenous zone. Signals from the sMT-Ia probe were present in the same cells, but were much weaker. No signals were detected using the sMT-Ic and sMT-II gene-specific probes. The findings suggest that: (1) MT is important in cell proliferation and/or cell differentiation in the hair follicle bulb; (2) MT translation is inhibited during cell differentiation and migration; and (3) tissue-specific expression of uncharacterized sMT isoforms is likely.

[Epidemiologic data, clinical and prognostic features of autosomal dominant polycystic kidney disease in a French region]. / Données épidémiologiques, cliniques et pronostiques de la maladie polykystique autosomique dominante dans une région française.

Epidemiological study on autosomal dominant polycystic kidney disease (ADPKD) was undertaken in a French region from 1988 to 1993. This survey was led in a population of 410,000 inhabitants and 84 kindreds with ADPKD and 296 affected members were studied. Prevalence of ADPKD in the studied region was calculated to 1/1111 inh. Renal prognosis was evaluated according to the Kaplan-Meier method in 296 affected subjects of whom 212 were members of propositus kindreds. In our region 17% of patients had ESRD by the age of 50 years, 47% by the age of 60 years and 70% by the age of 70. No significance difference was found between males and females. The influence of the sex of the parent from whom ADPKD was received on the renal prognosis of the disease in affected descendants was evaluated. Anticipation of ESRD for at least one offspring inheriting ADPKD from parent was found in 15 (38%) out of 39 families, without genetic imprinting linked to gender. Mean survival to ESRD for fathers transmitting ADPKD to offspring (52 +/- 10 years) was significantly earlier compared to that for mothers transmitting ADPKD (61 +/- 10 years, p < 0.001), therefore that for siblings inheriting the disease from their fathers (sons: 49 +/- 7 years, daughters: 51 +/- 9 years) and for those inheriting ADPKD from their mothers (sons: 57 +/- 10 yrs, p < 0.01, daughters: 55 +/- 6 yrs, p < 0.02). Prevalence of de novo mutations was evaluated to 1/135,000 inh. Adult polycystic disease of the liver (APLD) was studied in 82 kindreds with 158 ADPKD affected members by ultrasonography and/or CT. In patients with APLD, 49/84 (58.3%) were females compared to 46/74 (62.2%) in those without APLD. Familial APLD (at least 2 affected members and all with APLD) was demonstrated in 22/27 APLD kindreds (81.5%). Familial ADPKD without APLD (at least 2 affected members and all without APLD) was demonstrated in 12/12 kindreds (100%). Renal prognosis of ADPKD in 84 APLD pts was compared to that in 71 non-APLD pts, in whom mean age was not different at the time of the study. In APLD pts 28/84 (33.3%) had reached ESRD compared to 23/71 (32.3%) non-APLD pts (ns). The occurrence of stroke in ADPKD patients was documented in 24/231 pts (10.4%) from 11/82 kindreds (13.4%). Family history of cerebro-vascular event was found in 4/11 kindreds (36%).

Down-regulation of mitochondrial mRNAs in the mdx mouse model for Duchenne muscular dystrophy.

In our search for genes up- or down-regulated genes in the mdx mouse model for Duchenne muscular dystrophy, we isolated a down-regulated mitochondrial DNA clone. In addition to this clone, all protein-coding mitochondrial genes tested had tissue-specific and age independent down-regulated expression. This implied mechanisms at the RNA level since no change in the mitochondrial DNA contents were detected. Cytochrome c oxidase activity showed the same range of down-regulated expression. These data provide a molecular basis for energetic metabolism modifications in mdx mice.

Growth factor expression in skin during wool follicle development.

A variety of growth factors are likely to be involved in initiation and morphogenesis of wool follicles. To enable direct comparisons of the expression of different growth factors, reverse transcriptase-polymerase chain reactions (RT-PCR) were developed for ovine and murine TGF alpha, TGF beta 1, TGF beta 2, TGF beta 3, IGF1, IGF2, and FGF-2, which could all be carried out on a single cDNA sample. These RT-PCR were used with 16 sheep RNA samples from different foetal stages, neonatal sheep and mouse skin. The mRNAs for these growth factors were detected throughout gestation in sheep skin, except for TGF beta 1 mRNA which was not expressed in 51-day-old skin, but was expressed in 54-day and older samples. Since the first microscopically visible changes of follicle initiation occur around 62 days gestation, these results suggest that TGF beta 1 expression may be a signal for follicle initiation.

[Epidemiology of primary glomerulopathies in a French region. Variations as a function of age in patients]. / Epidémiologie des glomérulopathies primitives dans une région française. Variations en fonction des périodes et de l'âge des sujets.

Between January 1st, 1976 and December 31st, 1990, histological diagnosis of primary glomerular diseases (PGD) was made in 480 patients born and living at the time of diagnosis in a region of France comprising 410,664 inhabitants, of whom 390,574 were aged from 10 to 80 years. The prevalence of PGD during a 70-year exposure to risk (10-80 years of age) was evaluated to 5.7 in 1000 (7.6 in 1000 males and 3,8 in 1000 females). The most common PGD was IgA nephropathy with a prevalence of 1.9 in 1000 (3.3 in 1000 males, 1 in 1000 females). The annual incidence of the disease was evaluated separately for 3 consecutive 5-year periods: period A (1976-80), period B (1981-85), and period C (1986-90). Within each of these 3 periods the number of patients with PGD was 179, 170 and 131 respectively, and annual incidence was 9.3, 8.8 and 6.7 in 100,000. The incidence of IgA nephropathy remained the same throughout the 3 periods: 2.6, 3.1 and 2.5 in 100,000. The incidence of membranoproliferative glomerulonephritis decreased from 1981 onward (0.9, 0.5 and 0.15/100,000). Acute streptococcal glomerulonephritis virtually disappeared during periods B and C. Lipoid nephrosis was less frequent in period C and idiopathic proliferative glomerulonephritis with crescents slightly increased (0.3, 0.3 and 0.6 in 100,000). There was no significant difference between the 3 periods regarding the incidence of other PGD. Incidence of IgA nephropathy was 3 to 4-fold higher in the adult aged from 20 to 60 years than in the elderly. In contrast, membranous nephropathy was 3 fold more frequent in the elderly than in the adult. Therefore only some histopathological forms have a different incidence according to age, but the major information furnished by this study is that the risk of occurrence of a PGD is similar in the population living in the area, whatever the age group (10-19 years: 6.4/10(5) inhabitants, 20-39: 7.1/10(5), 40-59: 8.4/10(5), 60-79: 8.4/10(5)). Finally, we confirm that the most common PGD going to end stage renal disease was IgA nephropathy, particularly under 60 years of age (0.8/10(5)). In contrast, membranous nephropathy was a less frequent cause of ESRD (0.2/10(5)).

Epidemiology of primary glomerular diseases in a French region. Variations according to period and age.

Between January 1, 1976 and December 31, 1990, histological diagnosis of primary glomerular diseases (PGD) was made in 480 patients born and living at the time of diagnosis in a region of France, comprising 410,664 inhabitants, of whom 390,574 were aged from 10 to 80 years. The prevalence of PGD during a 70 year exposure to risk (10 to 80 years of age) was evaluated to 5.7 in 1000 (7.6 in 1000 males and 3.8 in 1000 females). The most common PGD was IgA nephropathy with a prevalence of 1.9 in 1000 (3.3 in 1000 males, 1 in 1000 females). The annual incidence of the disease was evaluated separately for three consecutive five-year periods: period A (1976-80), period B (1981-85), and period C (1986-90). Within each of these three periods the number of patients with PGD was 179, 170 and 131, respectively, and annual incidence was 9.3, 8.8 and 6.7 in 100,000. The incidence of IgA nephropathy remained the same throughout the three periods: 2.6, 3.1 and 2.5 in 100,000. The incidence of membranoproliferative glomerulonephritis decreased from 1981 onward (0.9, 0.5 and 0.15 in 100,000), while that of membranous nephropathy increased slightly (1.2, 1.6 and 1.7 in 100,000). Acute streptococcal glomerulonephritis virtually disappeared during periods B and C. Lipoid nephrosis was less frequent in period C and idiopathic proliferative glomerulonephritis with crescents slightly increased (0.3, 0.4 and 0.6 in 100,000). There was no significant difference between the three periods regarding the incidence of other PGD.(ABSTRACT TRUNCATED AT 250 WORDS)

Indices of adequate dialysis in patients hemodialyzed with AN 69 membrane.

The objective of this study was to evaluate the incidence of morbidity (at least one hospitalization) during the first twelve months of hemodialysis (thrice weekly for 4 hours) in 54 (27 males and 27 females) sex and age matched patients, of whom 32 were treated with AN 69 (M/F = 13/19, 62 +/- 14 years) and 22 with Cuprophan (M/F = 14/8, 61 +/- 14 years). Patients were classified according to the value of TAC urea during the period under study: constantly superior or equal to 20 mmol/liter in Group A (high TAC urea) or inferior to 20 mmol/liter in Group B (low TAC urea). Dialysis quantification (Kt/V) and estimation of the patient's protein catabolic rate (PCR) were based on measurement of the midweek pre- and post-dialysis blood urea nitrogen. In the patients of Group B, incidence of morbidity was significantly increased when age was over 50 years and when AN 69 membrane was used (P < 0.02). Furthermore, in Group A, the risk of hospitalization was significantly higher in patients treated by Cuprophan than in those treated by AN 69 (P < 0.02). The survival rate was also studied. Better survival (70%) at four years was observed in patients with high TAC urea who were treated by AN 69. The difference was highly significant with the survival rate (22%) in patients with high TAC urea who were treated by Cuprophan (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Transfected Go1 alpha inhibits the calcium dependence of beta-adrenergic stimulated cAMP accumulation in C6 glioma cells.

Increasing evidence indicates that heterotrimeric G proteins, and in particular Go, regulate ionic channel activities. In order to investigate the role of Go proteins in the modulation of the Ca2+ influx, C6 glioma cells were stably transfected with alpha o1 cDNA. Expression of the Go1 alpha protein was checked by Bordetella pertussis toxin-catalyzed ADP-ribosylation and Western blots using one- and two-dimensional gel analyses. Three clones were selected based on their degree of Go1 alpha expression. In alpha o1-transfected cells, cAMP accumulations, in response to isoproterenol or forskolin, were lower than in control cells. This inhibitory effect was a function of the amount of expressed Go1 alpha. In contrast, Go1 alpha expression was not followed by a significant inhibition of isoproterenol- or forskolin-stimulated adenylyl cyclase activities in particulate fractions. In C6 parental cells, 50-60% of the isoproterenol-induced cAMP accumulation was dependent on external Ca2+ concentration. This Ca(2+)-dependent cAMP accumulation was related to an induced transient Ca2+ influx. In transfected cells, expression of Go1 alpha inhibited the Ca2+ influx and the Ca(2+)-dependent component of isoproterenol-induced cAMP accumulation. In conclusion, beta-adrenergic agonists stimulate an entry of Ca2+ which exerts a positive feedback on cAMP production, and Go1 alpha blocks this positive feedback by inhibiting the Ca2+ influx.

[Genetic and environmental factors implicated in recurrent calcium lithiasis]. / Facteurs génétiques et environnementaux impliqués dans la lithiase calcique récidivante.

In this prospective study, we compared the frequency of some genetic and environmental factors possibly implicated in the occurrence of calcium stone disease. A group of 439 patients (258 males and 181 females) with one episode of calcium stone was compared to a group of 191 patients (131 males and 60 females) with recurrent calcium stone disease. Population with stones was also compared to control population (n = 78, 40 males and 38 females) matched to age. Major results were as follow: 1) Family history of urinary calculi was more frequent in patients than in controls (28.4% vs 9%, p < 0.01). No difference was observed between patients with one episode and those with recurrent episodes (27% vs 31%, ns). 2) The recurrence was earlier in female than in male, so that in female with family history of urinary calculi (p < 0.05). 3) Mean plasma levels of 1-25OH2D3 was significantly higher in patients with family history than in controls (60% vs 38%, p < 0.01) 5) Restricted calcium diet (< 400 mg per day) was more often observed in patients than in controls (31% vs 14%, p < 0.05) and the most significant difference was found in patients with recurrent calcium stones.

[Short and long term complications of lithotripsy on renal function]. / Séquelles à court et moyen termes de la lithotripsie sur la fonction rénale.

Today, most stones can be removed by minimally invasive means. Extracorporeal Shock Wave Lithotripsy (ESWL) is the preferred form of treatment for symptomatic upper ureteral and renal calculi less than 2 cm a diameter. The short and long term complications of ESWL are underestimated. Thus, ESWL may cause renal trauma and such trauma may induce later hypertension. In this retrospective study, we reviewed the frequency of deleterious effects of ESWL in 45 patients who had undergone ESWL from January 1988 to September 1989. Short-term complications were macroscopic hematuria (15%), lumbar pain (11%) and peri- or intrarenal hematomas (4.4%). Two years later CT scan was performed in 20 patients. It was normal in 7 (35%). In others, it shown a recurrence of stone in 8 (40%) and a focal scarring in 5 (25%). Only 1 out of 43 patients had developed hypertension.

myc protooncogenes of wool and hair growth.

The growth of hard keratin fibers such as wool and hair is dependent on the proliferation of cells in the follicle bulb. If the cells leaving the bulb could be induced to undergo an extra division, then fiber growth should increase. The cellular division within the follicle is complex and probably involves one or more growth factors, which act by altering the expression of transcription factors and other nuclear proteins. We propose that the expression of the myc protooncogenes is a central part of this mechanism. In support of this hypothesis we have detected the mRNAs for TGF-beta 1, basic FGF, TGF-alpha, and c-myc in plucked wool follicles using PCR amplification. We have also shown that the TGF-beta 1, TGF-beta 2, TGF-beta 3, EGF, TGF-alpha, basic FGF, N-myc, and c-myc genes are expressed in mouse skin, and we looked for changes during the hair cycle. The PCR data suggest that in whole skin the levels of mRNA for TGF-beta 1, TGF-beta 2, TGF-alpha, and c-myc do not change. In Quackenbush mice the levels for N-myc, TGF-beta 3, and basic FGF mRNA appear to be lower at the end of the hair cycle. We have confirmed in CBA/C57 black mice that lower levels of N-myc mRNA are detected when hair growth ceases in catagen and telogen. To test our hypothesis further and to assess its practical application, we are making transgenic mice in which the N-myc gene is overexpressed in the hair follicle by way of a wool keratin promoter. The transgene consists of 3.3 kb of 5' sequence from an ovine type 1 IF gene, the murine N-myc genomic coding sequence, and an SV40 polyadenylation signal. The native keratin type 1 IF gene is expressed exclusively in the wool follicle, as shown by in situ hybridization. However, in mice the injection of the transgene has resulted in high embryonic mortality and some embryos with large body size and head malformations. Since these mice were not transgenic, this is likely to be an effect of transient expression of the transgene during embryogenesis. The two transgenic mice produced so far have a normal phenotype.