Purification and characterization of an asialofetuin specific lectin from the rhizome of Xanthosoma violaceum Schott

Lectins are proteins or glycoproteins that bind specifically and reversibly to the carbohydrate or glycoconjugates. A new lectin is purified from the rhizome of Xanthosoma violaceum Schott. by successive steps of ammonium sulfate fractionation and affinity chromatography with asialofetuin as ligand. The purified lectin was found to be a homotetramer of approximately 49 kDa with a subunit molecular weight of 12 kDa linked by non-covalent bonds. Characterization of the lectin shows that the hemagglutination activity is inhibited by asialofetuin and d-galacturonic acid. Hemagglutination activity is shown only in rabbit RBC but not in the human RBC of all blood groups. It is a metal ion-independent glycoprotein of 1.87% carbohydrate content, stable upto 40 °C and pH from 5.5 to 9. The lectin shows its optimum hemagglutination activity at 0 °C-40 °C and pH 6 to 8.5. From LC-MS/MS analysis it is confirmed that the purified lectin was not purified and characterized earlier.

Morpho-molecular characterisation of two new and two previously reported species of Acanthogyrus (Acanthogyrus: Quadrigyridae) from freshwater fishes in India

Of the total 47 species in the subgenus Acanthosentis, 43 have been reported from the freshwater fishes of Asia. Amin et al. (2017) provided a key to the 23 species of the genus Acanthogyrus reported from the Indian subcontinent. The present study reports two new species: Acanthogyrus bispinosa n. sp. and A. garciai n. sp. from Cirrhinus mrigala Hamilton and Labeo calbasu Hamilton, respectively, and two previously described species: A. golvani Gupta and Jain, 1980 and A. hereterospinus Khan and Bilqees, 1990 from L. rohita Hamilton and L. catla Hamilton, respectively. A. bispinosa n. sp. comprises 3 circles of 6 proboscis hooks each. Trunk spines in A. bispinosa n. sp are divided into two groups: anterior and posterior separated by unarmed region, which has not been previously reported in the subgenus. Anterior spines are present in 7-8 and 7-10 circles in females and males, respectively, whereas posterior spines are in 23-28 and 31-38 circles in males and females, respectively. A. garciai n. sp. comprises 3 circles of 6-8 hooks each and a single set of trunk spines is present in A. garciai n. sp., comprising 35-42 and 25-45 circles in males and females, respectively. All four species were also characterised based on the 18S, 28S, and ITS1-5.8S-ITS2 rRNA molecular markers. The Bayesian inference tree generated based on these markers showed distinct identities of all the species, with a significant molecular divergence, ranging from 3.2 to 53.6%.

Insertion of an intrathecal catheter following a recognised accidental dural puncture reduces the need for an epidural blood patch in parturients: an Australian retrospective study

BACKGROUND

There is no clear consensus about how best to prevent post-dural puncture headache (PDPH) following an accidental dural puncture in parturients. Our primary objective was to investigate whether the insertion of an intrathecal catheter following accidental dural puncture reduces the incidence of PDPH and therapeutic epidural blood patch.

METHODS

Anaesthetic records from January 2009 to December 2015 were reviewed retrospectively and parturients who had an accidental dural puncture and/or PDPH were identified. Data from those with a recognised dural puncture in whom an intrathecal catheter was inserted at the time of accidental dural puncture (ITC group) were compared to those without an intrathecal catheter (non-ITC group), as were outcomes of patients with an intrathecal catheter for ≥24 hours compared to <24 hours.

RESULTS

Of 94 recognised accidental dural punctures, 66 were in the ITC group (37 for ≥24 h) and 28 in the non-ITC group. In the ITC group, 22 (33.3%) required an epidural blood patch in comparison to 19 (67.9%) in the non-ITC group (P <0.01, 95% CI 12.5 to 52.0). In the ITC group, 62 (93.9%) developed PDPH in comparison to 28 (100%) in the non-ITC group (P=0.186, 95% CI -6.55 to 14.57). Intrathecal catheter insertion for ≥24 h obviated the need for an epidural blood patch in 28 (75.7%) parturients, compared to 13 (59.1%) if <24 h (P=0.184, 95% CI -7.08 to 39.72).

CONCLUSION

Inserting an intrathecal catheter after a recognised accidental dural puncture significantly reduced the need for an epidural blood patch.

A rare case of haemorrhagic shock secondary to spontaneous rupture of a branch of the left colic artery and the right gastric artery

Spontaneous splanchnic artery rupture is associated with up to 70% mortality. Affected vessels are often aneurysmal, secondary to atherosclerosis. We report, to our knowledge, the only case of spontaneous rupture of a branch of the left colic artery and the right gastric artery, possibly secondary to vasculitis.

Actin alpha cardiac muscle 1 gene expression is upregulated in the skeletal muscle of men undergoing androgen deprivation therapy for prostate cancer

Androgen deprivation therapy (ADT) decreases muscle mass and function but no human studies have investigated the underlying genetic or cellular effects. We tested the hypothesis that ADT will lead to changes in skeletal muscle gene expression, which may explain the adverse muscle phenotype seen clinically. We conducted a prospective cohort study of 9 men with localised prostate cancer who underwent a vastus lateralis biopsy before and after 4 weeks of ADT. Next-generation RNA sequencing was performed and genes differentially expressed following ADT underwent gene ontology mining using Ingenuity Pathway Analysis. Differential expression of genes of interest was confirmed by quantitative PCR (Q-PCR) on gastrocnemius muscle of orchidectomised mice and sham controls (n=11/group). We found that in men, circulating total testosterone decreased from 16.5±4.3nmol/L at baseline to 0.4±0.15nmol/L post-ADT (p<0.001). RNA sequencing identified 19 differentially expressed genes post-ADT (all p<0.05 after adjusting for multiple testing). Gene ontology mining identified 8 genes to be of particular interest due to known roles in androgen-mediated signalling; ABCG1, ACTC1, ANKRD1, DMPK, THY1, DCLK1, CST3 were upregulated and SLC38A3 was downregulated post-ADT. Q-PCR in mouse gastrocnemius muscle confirmed that only one gene, Actc1 was concordantly upregulated (p<0.01) in orchidectomised mice compared with controls. In conclusion, given that ACTC1 upregulation is associated with improved muscle function in certain myopathies, we hypothesise that upregulation of ACTC1 may represent a compensatory response to ADT-induced muscle loss. Further studies will be required to evaluate the role and function of ACTC1.

Androgen Action via the Androgen Receptor in Neurons Within the Brain Positively Regulates Muscle Mass in Male Mice

Although it is well established that exogenous androgens have anabolic effects on skeletal muscle mass in humans and mice, data from muscle-specific androgen receptor (AR) knockout (ARKO) mice indicate that myocytic expression of the AR is dispensable for hind-limb muscle mass accrual in males. To identify possible indirect actions of androgens via the AR in neurons to regulate muscle, we generated neuron-ARKO mice in which the dominant DNA binding-dependent actions of the AR are deleted in neurons of the cortex, forebrain, hypothalamus, and olfactory bulb. Serum testosterone and luteinizing hormone levels were elevated twofold in neuron-ARKO males compared with wild-type littermates due to disruption of negative feedback to the hypothalamic-pituitary-gonadal axis. Despite this increase in serum testosterone levels, which was expected to increase muscle mass, the mass of the mixed-fiber gastrocnemius (Gast) and the fast-twitch fiber extensor digitorum longus hind-limb muscles was decreased by 10% in neuron-ARKOs at 12 weeks of age, whereas muscle strength and fatigue of the Gast were unaffected. The mass of the soleus muscle, however, which consists of a high proportion of slow-twitch fibers, was unaffected in neuron-ARKOs, demonstrating a stimulatory action of androgens via the AR in neurons to increase the mass of fast-twitch hind-limb muscles. Furthermore, neuron-ARKOs displayed reductions in voluntary and involuntary physical activity by up to 60%. These data provide evidence for a role of androgens via the AR in neurons to positively regulate fast-twitch hind-limb muscle mass and physical activity in male mice.

A microfluidic model of hemostasis sensitive to platelet function and coagulation

Hemostasis is the process of sealing a vascular injury with a thrombus to arrest bleeding. The type of thrombus that forms depends on the nature of the injury and hemodynamics. There are many models of intravascular thrombus formation whereby blood is exposed to prothrombotic molecules on a solid substrate. However, there are few models of extravascular thrombus formation whereby blood escapes into the extravascular space through a hole in the vessel wall. Here, we describe a microfluidic model of hemostasis that includes vascular, vessel wall, and extravascular compartments. Type I collagen and tissue factor, which support platelet adhesion and initiate coagulation, respectively, were adsorbed to the wall of the injury channel and act synergistically to yield a stable thrombus that stops blood loss into the extravascular compartment in ~7.5 min. Inhibiting factor VIII to mimic hemophilia A results in an unstable thrombus that was unable to close the injury. Treatment with a P2Y12 antagonist to reduce platelet activation prolonged the closure time two-fold compared to controls. Taken together, these data demonstrate a hemostatic model that is sensitive to both coagulation and platelet function and can be used to study coagulopathies and platelet dysfunction that result in excessive blood loss.

Muscle-specific androgen receptor deletion shows limited actions in myoblasts but not in myofibers in different muscles in vivo

The aim of this study was to investigate the direct muscle cell-mediated actions of androgens by comparing two different mouse lines. The cre-loxP system was used to delete the DNA-binding activity of the androgen receptor (AR) in mature myofibers (MCK mAR(ΔZF2)) in one model and the DNA-binding activity of the AR in both proliferating myoblasts and myofibers (α-actin mAR(ΔZF2)) in another model. We found that hind-limb muscle mass was normal in MCK mAR(ΔZF2) mice and that relative mass of only some hind-limb muscles was reduced in α-actin mAR(ΔZF2) mice. This suggests that myoblasts and myofibers are not the major cellular targets mediating the anabolic actions of androgens on male muscle during growth and development. Levator ani muscle mass was decreased in both mouse lines, demonstrating that there is a myofiber-specific effect in this unique androgen-dependent muscle. We found that the pattern of expression of genes including c-myc, Fzd4 and Igf2 is associated with androgen-dependent changes in muscle mass; therefore, these genes are likely to be mediators of anabolic actions of androgens. Further research is required to identify the major targets of androgen actions in muscle, which are likely to include indirect actions via other tissues.

A vascular injury model using focal heat-induced activation of endothelial cells

Endothelial cells (EC) both inhibit and promote platelet function depending on their activation state. Quiescent EC inhibit platelet activation by constitutive secretion of platelet inhibitors. Activated EC promote platelet adhesion by secretion of von Willebrand factor (vWF). EC also secrete an extracellular matrix that support platelet adhesion when exposed following vascular injury. Previous studies of EC-platelet interactions under flow activate entire monolayers of cells by chemical activation. In this study, EC cultured in microfluidic channels were focally activated by heat from an underlying microelectrode. Based on finite element modeling, microelectrodes induced peak temperature increases of 10-40 °C above 37 °C after applying 5-9 V for 30 s resulting in three zones: (1) a quiescent zone corresponded to peak temperatures of less than 15 °C characterized by no EC activation or platelet accumulation. (2) An activation zone corresponding to an increase of 16-22 °C yielded EC that were viable, secreted elevated levels of vWF, and were P-selectin positive. Platelets accumulated in the retracted spaces between EC in the activation zone at a wall shear rate of 150 and 1500 s(-1). Experiments with blocking antibodies show that platelets adhere via GPIbα-vWF and α6β1-laminin interactions. (3) A kill zone corresponded to peak temperatures of greater than 23 °C where EC were not viable and did not support platelet adhesion. These data define heating conditions for the activation of EC, causing the secretion of vWF and the exposure of a subendothelial matrix that support platelet adhesion and aggregation. This model provides for spatially defined zones of EC activation that could be a useful tool for measuring the relative roles of anti- and prothrombotic roles of EC at the site of vascular injury.

Expression of androgen receptor target genes in skeletal muscle

We aimed to determine the mechanisms of the anabolic actions of androgens in skeletal muscle by investigating potential androgen receptor (AR)-regulated genes in in vitro and in vivo models. The expression of the myogenic regulatory factor myogenin was significantly decreased in skeletal muscle from testosterone-treated orchidectomized male mice compared to control orchidectomized males, and was increased in muscle from male AR knockout mice that lacked DNA binding activity (AR^ΔZF2) versus wildtype mice, demonstrating that myogenin is repressed by the androgen/AR pathway. The ubiquitin ligase Fbxo32 was repressed by 12 h dihydrotestosterone treatment in human skeletal muscle cell myoblasts, and c-Myc expression was decreased in testosterone-treated orchidectomized male muscle compared to control orchidectomized male muscle, and increased in AR^ΔZF2 muscle. The expression of a group of genes that regulate the transition from myoblast proliferation to differentiation, Tceal7, p57^Kip2, Igf2 and calcineurin Aa, was increased in AR^ΔZF2 muscle, and the expression of all but p57^Kip2 was also decreased in testosterone-treated orchidectomized male muscle compared to control orchidectomized male muscle. We conclude that in males, androgens act via the AR in part to promote peak muscle mass by maintaining myoblasts in the proliferative state and delaying the transition to differentiation during muscle growth and development, and by suppressing ubiquitin ligase-mediated atrophy pathways to preserve muscle mass in adult muscle.

Human androgen deficiency: insights gained from androgen receptor knockout mouse models

The mechanism of androgen action is complex. Recently, significant advances have been made into our understanding of how androgens act via the androgen receptor (AR) through the use of genetically modified mouse models. A number of global and tissue-specific AR knockout (ARKO) models have been generated using the Cre-loxP system which allows tissue- and/or cell-specific deletion. These ARKO models have examined a number of sites of androgen action including the cardiovascular system, the immune and hemopoetic system, bone, muscle, adipose tissue, the prostate and the brain. This review focuses on the insights that have been gained into human androgen deficiency through the use of ARKO mouse models at each of these sites of action, and highlights the strengths and limitations of these Cre-loxP mouse models that should be considered to ensure accurate interpretation of the phenotype.

Normal phenotype in conditional androgen receptor (AR) exon 3-floxed neomycin-negative male mice

Androgens (testosterone and dihydrotestosterone) acting via the androgen receptor (AR) are required for male sexual differentiation, and also regulate the development of many other tissues including muscle, fat and bone. We previously generated an AR(lox) mouse line with exon 3 of the AR gene targeted by loxP sites. The deletion of exon 3 is in-frame, so only the DNA binding-dependent actions of the AR are deleted, but non-DNA binding-dependent actions are retained. This line also contained an antibiotic resistance selection cassette, neomycin (neo) in intron 3, which was also flanked by loxP sites. Hemizygous AR(lox) male mice demonstrated a phenotype of hyperandrogenization, with increased mass of androgen-dependent tissues. We hypothesized that this hyperandrogenization was likely to be due to the presence of the neo cassette. In this study, we have generated an AR(lox) neo-negative mouse line, using the EIIa-cre deleter mouse line to remove the neo cassette. Hemizygous AR(lox) neo-negative male mice have a normal phenotype, with normal body mass and normal mass of androgen-dependent tissues including the testis, seminal vesicles, kidney, spleen, heart and retroperitoneal fat. This neo-negative exon 3-targeted mouse line is the only floxed AR mouse line available to study the DNA binding-dependent actions of the AR in a tissue-specific manner, and is suitable for investigation in all tissues. This study demonstrates the importance of removing the selection cassette, which can potentially alter the phenotype of floxed mouse lines even in the absence of detectable effects on target gene expression.

Synthesis, in vitro Anticancer and Antimicrobial Evaluation of Novel Substituted Dihydropyrimidines

A series of 1,4-dihydropyrimidine derivatives 3(a-t) were prepared from Biginelli reactions by using ethyl acetoacetate, substituted benzaldehyde and thiourea in the presence of piperidine and ethanol. The compounds 3(a-t) were reacted with dimethylsulphate, diethylsulphate, butyl bromide and benzyl chloride to give the new series of compounds 4(a-t). The structures of the newly synthesized compounds 4(a-t) were established by IR, (1)H NMR, Mass spectra and elemental analysis. The synthesized compounds were evaluated for their in vitro anticancer activity by using Sulforhodamine B assay method against the growth of four humans cancer cell lines, antibacterial activity against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli and for antifungal activity against Candida albicans and Aspergillus niger. The compounds exhibited good anticancer activity and moderate antibacterial and antifungal activities. Compounds 4b, 4c, 4d, 4g, 4i, 4n, 4o, 4q and 4s showed significant anticancer activity when compared with the doxorubicin as a standard reference drug.

Expression of Wnt signaling skeletal development genes in the cartilaginous fish, elephant shark (Callorhinchus milii)

Jawed vertebrates (Gnasthostomes) are broadly separated into cartilaginous fishes (Chondricthyes) and bony vertebrates (Osteichthyes). Cartilaginous fishes are divided into chimaeras (e.g. ratfish, rabbit fish and elephant shark) and elasmobranchs (e.g. sharks, rays and skates). Both cartilaginous fish and bony vertebrates are believed to have a common armoured bony ancestor (Class Placodermi), however cartilaginous fish are believed to have lost bone. This study has identified and investigated genes involved in skeletal development in vertebrates, in the cartilaginous fish, elephant shark (Callorhinchus milii). Ctnnb1 (β-catenin), Sfrp (secreted frizzled protein) and a single Sost or Sostdc1 gene (sclerostin or sclerostin domain-containing protein 1) were identified in the elephant shark genome and found to be expressed in a number of tissues, including cartilage. β-catenin was also localized in several elephant shark tissues. The expression of these genes, which belong to the Wnt/β-catenin pathway, is required for normal bone formation in mammals. These findings in the cartilaginous skeleton of elephant shark support the hypothesis that the common ancestor of cartilaginous fishes and bony vertebrates had the potential for making bone.

Increased adiposity in DNA binding-dependent androgen receptor knockout male mice associated with decreased voluntary activity and not insulin resistance

In men, as testosterone levels decrease, fat mass increases and muscle mass decreases. Increased fat mass in men, in particular central obesity, is a major risk factor for type 2 diabetes, cardiovascular disease, and all-cause mortality. Testosterone treatment has been shown to decrease fat mass and increase fat-free mass. We hypothesize that androgens act directly via the DNA binding-dependent actions of the androgen receptor (AR) to regulate genes controlling fat mass and metabolism. The aim of this study was to determine the effect of a global DNA binding-dependent (DBD) AR knockout (DBD-ARKO) on the metabolic phenotype in male mice by measuring body mass, fat mass, food intake, voluntary physical activity, resting energy expenditure, substrate oxidation rates, serum glucose, insulin, lipid, and hormone levels, and metabolic gene expression levels and second messenger protein levels. DBD-ARKO males have increased adiposity despite a decreased total body mass compared with wild-type (WT) males. DBD-ARKO males showed reduced voluntary activity, decreased food intake, increased serum leptin and adiponectin levels, an altered lipid metabolism gene profile, and increased phosphorylated CREB levels compared with WT males. This study demonstrates that androgens acting via the DNA binding-dependent actions of the AR regulate fat mass and metabolism in males and that the increased adiposity in DBD-ARKO male mice is associated with decreased voluntary activity, hyperleptinemia and hyperadiponectinemia and not with insulin resistance, increased food intake, or decreased resting energy expenditure.

The innate immune response, clinical outcomes, and ex vivo HCV antiviral efficacy of a TLR7 agonist (PF-4878691)

Hepatitis C virus (HCV) infection is an issue of global concern, and studies are ongoing to identify new therapies that are both effective and safe. PF-4878691 is a Toll-like receptor 7 (TLR7) agonist modeled so as to dissociate its antiviral activities from its inflammatory activities. In a proof-of-mechanism study in healthy volunteers who received doses of 3, 6, and 9 mg of PF-4878691 twice a week for 2 weeks, PF-4878691 induced biomarkers of the immune and interferon (IFN) responses in a dose-dependent and dose-frequency-related manner. A novel finding was induction of TLR7 expression in vivo in response to PF-4878691, leading to an amplified biomarker response. A nonresponder at the 9-mg dose had a polymorphism in the IFN-α receptor 1 subunit (Val168Leu). Two subjects who had received 9-mg doses experienced serious adverse events (SAEs), characterized by flu-like symptoms, hypotension, and lymphopenia, leading to early termination of the study. TLR7 stimulation results in a pharmacologic response at levels commensurate with predicted antiviral efficacy, but these doses are associated with SAEs, raising concerns about the therapeutic window of this class of compounds for the treatment of HCV infection.

DNA-binding-dependent androgen receptor signaling contributes to gender differences and has physiological actions in males and females

We used our genomic androgen receptor (AR) knockout (ARKO) mouse model, in which the AR is unable to bind DNA to: 1) document gender differences between males and females; 2) identify the genomic (DNA-binding-dependent) AR-mediated actions in males; 3) determine the contribution of genomic AR-mediated actions to these gender differences; and 4) identify physiological genomic AR-mediated actions in females. At 9 weeks of age, control males had higher body, heart and kidney mass, lower spleen mass, and longer and larger bones compared to control females. Compared to control males, ARKO males had lower body and kidney mass, higher splenic mass, and reductions in cortical and trabecular bone. Deletion of the AR in ARKO males abolished the gender differences in heart and cortical bone. Compared with control females, ARKO females had normal body weight, but 14% lower heart mass and heart weight/body weight ratio. Relative kidney mass was also reduced, and relative spleen mass was increased. ARKO females had a significant reduction in cortical bone growth and changes in trabecular architecture, although with no net change in trabecular bone volume. In conclusion, we have shown that androgens acting via the genomic AR signaling pathway mediate, at least in part, the gender differences in body mass, heart, kidney, spleen, and bone, and play a physiological role in the regulation of cardiac, kidney and splenic size, cortical bone growth, and trabecular bone architecture in females.

Do mutations in COL4A1 or COL4A2 cause thin basement membrane nephropathy (TBMN)?

Thin basement membrane nephropathy (TBMN) is the commonest cause of persistent glomerular haematuria and often presents in childhood. Only 40% of affected individuals have mutations identified in the COL4A3 and COL4A4 genes, but mutations in the genes for other COL4A isoforms also result in thinned membranes in humans (COL4A5) and mice (COL4A1). This study examined whether COL4A1/COL4A2 represented a further genetic locus for TBMN. Nine families with TBMN in whom haematuria did not segregate with COL4A3/COL4A4, were examined for linkage to COL4A1/COL4A2 using five micro-satellite markers. In addition, index cases from these families plus a further 14 unrelated individuals with TBMN that was not due to COL4A3 or COL4A4 mutations (n=23) were screened for mutations in each of the 52 exons of COL4A1 and the 47 exons of COL4A2 using single stranded conformational analysis (SSCA). DNA samples that demonstrated bandshifts were sequenced. Haplotype analysis demonstrated that haematuria segregated with the COL4A1/COL4A2 locus in only two small families (2/9, 22%). No definite COL4A1 or COL4A2 mutations were identified in the 23 unrelated individuals with TBMN although novel polymorphisms were demonstrated. This study indicates that COL4A1/COL4A2 does not represent a further major genetic locus for TBMN.

Nine novel COL4A3 and COL4A4 mutations and polymorphisms identified in inherited membrane diseases

Both thin basement membrane nephropathy (TBMN) and autosomal recessive Alport syndrome result from mutations in the COL4A3 and COL4A4 genes, and this study documents further mutations and polymorphisms in these genes. Thirteen unrelated children with TBMN and five individuals with autosomal recessive Alport syndrome were examined for mutations in the 52 exons of COL4A3 and the 47 coding exons of COL4A4 using single-stranded conformation polymorphism (SSCP) analysis. Amplicons producing different electrophoretic patterns were sequenced, and mutations were defined as variants that changed an amino acid but were not present in 50 non-hematuric normals. Three further novel mutations were identified. These were IVS 22-5 T>A in the COL4A3 gene in a consanguineous family with autosomal recessive Alport syndrome, and R1677C and R1682Q in the COL4A4 gene. In addition, six novel polymorphisms (G455G, I462I, G736G and IVS 38-8 G>A in COL4A3, and L658L and A1577A in COL4A4) were demonstrated.Many different COL4A3 and COL4A4 mutations cause TBMN and autosomal recessive Alport syndrome. The identification of polymorphisms in these genes is particularly important to enable diagnostic laboratories to distinguish mutations from uncommon normal variants.

Persistent familial hematuria in children and the locus for thin basement membrane nephropathy

This study examined how often children with persistent familial hematuria were from families where hematuria segregated with the known genetic locus for the condition known as benign familial hematuria or thin basement membrane nephropathy (TBMN) at COL4A3/COL4A4. Twenty-one unrelated children with persistent familial hematuria as well as their families were studied for segregation of hematuria with haplotypes at the COL4A3/COL4A4 locus for benign familial hematuria and at the COL4A5 locus for X-linked Alport syndrome. Eight families (38%) had hematuria that segregated with COL4A3/COL4A4, and four (19%) had hematuria that segregated with COL4A5. At most, eight of the other nine families could be explained by disease at the COL4A3/COL4A4 locus if de novo mutations, non-penetrant hematuria or coincidental hematuria in unaffected family members was present individually or in combination. This study confirms that persistent familial hematuria is not always linked to COL4A3/COL4A4 (or COL4A5) and suggests the possibility of a further genetic locus for benign familial hematuria. This study also highlights the risk of excluding X-linked Alport syndrome on the basis of the absence of a family history or of kidney failure.

The Genetics of Thin Basement Membrane Nephropathy

The diagnosis of thin basement membrane nephropathy (TBMN) usually is made on the basis of the clinical features or the glomerular membrane ultrastructural appearance. Only now are we beginning to understand the genetics of TBMN and the role of diagnostic genetic testing. The similarity of clinical and glomerular membrane features first suggested TBMN might represent the carrier state for autosomal-recessive Alport syndrome. This was confirmed subsequently by the demonstration that 40% of families with TBMN have hematuria that segregates with the corresponding locus ( COL4A3/COL4A4 ), and identical mutations occur in both conditions. To date, about 20 COL4A3 and COL4A4 mutations have been shown in TBMN, and these mainly are single nucleotide substitutions that are different in each family. The families in whom hematuria does not appear to segregate with the COL4A3/COL4A4 locus cannot all be explained by de novo mutations, and nonpenetrant or coincidental hematuria. This suggests a further TBMN locus. In patients with persistent hematuria, testing for COL4A3 and COL4A4 mutations to diagnose TBMN is problematic because of the huge size of these genes, their frequent polymorphisms, and the likelihood of a further gene locus. It is far more practicable to perform genetic testing to exclude or confirm X-linked Alport syndrome because this condition is the major differential diagnosis of TBMN and has a very different prognosis.

COL4A3 mutations and their clinical consequences in thin basement membrane nephropathy (TBMN)

BACKGROUND

Thin basement membrane nephropathy (TBMN) is often caused by mutations in the COL4A3 and COL4A4 genes.

METHODS

We examined 62 unrelated individuals diagnosed with TBMN by renal biopsy (N= 49, 79%) or a positive family history of hematuria but without a biopsy (N= 13, 21%) for mutations in the COL4A3 gene and the COL4A3/COL4A4 promoter. All 52 exons of COL4A3 as well as the COL4A3/COL4A4 promoter were screened with single-stranded conformational polymorphism (SSCP) analysis at 4 degrees C and at room temperature. Amplicons that demonstrated electrophoretic abnormalities were sequenced.

RESULTS

Seven mutations were demonstrated in seven patients: G532C and G584C in exon 25, G596R in exon 26, G695R in exon 28, and IVS 2224 - 11C>T, IVS 2980 + 1G>A and IVS 3518 - 7C>G. No mutations were found in the COL4A3/COL4A4 promoter. Four novel polymorphisms or variants (P116T in exon 6, P690P in exon 27, and G895G and A899A in exon 33) were also demonstrated. In addition, P1109S and Q1495R, which had been described previously but whose status was unclear, were shown to be polymorphisms. All seven mutations described here were associated with hematuria. While one mutation (2980 + 1G>A) was found in an individual who also had proteinuria, none of her family members with the same mutation had increased urinary protein. None of the patients with these seven mutations had renal impairment. Hematuria was completely penetrant in families with the G532C, G584C, G596R, and IVS 2980 + 1G>A mutations but not with the G695R and IVS 3518 - 7C>G mutations.

CONCLUSION

COL4A3 mutations are common in TBMN.

Thin basement membrane nephropathy

Thin basement membrane nephropathy. Thin basement membrane nephropathy (TBMN) is the most common cause of persistent glomerular bleeding in children and adults, and occurs in at least 1% of the population. Most affected individuals have, in addition to the hematuria, minimal proteinuria, normal renal function, a uniformly thinned glomerular basement membrane (GBM) and a family history of hematuria. Their clinical course is usually benign. However, some adults with TBMN have proteinuria >500 mg/day or renal impairment. This is more likely in hospital-based series of biopsied patients than in the uninvestigated, but affected, family members. The cause of renal impairment in TBMN is usually not known, but may be due to secondary focal segmental glomerulosclerosis (FSGS) or immunoglobulin A (IgA) glomerulonephritis, to misdiagnosed IgA disease or X-linked Alport syndrome, or because of coincidental disease. About 40% families with TBMN have hematuria that segregates with the COL4A3/COL4A4 locus, and many COL4A3 and COL4A4 mutations have now been described. These genes are also affected in autosomal-recessive Alport syndrome, and at least some cases of TBMN represent the carrier state for this condition. Families with TBMN in whom hematuria does not segregate with the COL4A3/COL4A4 locus can be explained by de novo mutations, incomplete penetrance of hematuria, coincidental hematuria in family members without COL4A3 or COL4A4 mutations, and by a novel gene locus for TBMN. A renal biopsy is warranted in TBMN only if there are atypical features, or if IgA disease or X-linked Alport syndrome cannot be excluded clinically. In IgA disease, there is usually no family history of hematuria. X-linked Alport syndrome is much less common than TBMN and can often be identified in family members by its typical clinical features (including retinopathy), a lamellated GBM without the collagen alpha3(IV), alpha4(IV), and alpha5(IV) chains, and by gene linkage studies or the demonstration of a COL4A5 mutation. Technical difficulties in the demonstration and interpretation of COL4A3 and COL4A4 mutations mean that mutation detection is not used routinely in the diagnosis of TBMN.

Clinical, histopathologic, and genetic studies in nine families with focal segmental glomerulosclerosis

BACKGROUND

Familial forms of focal segmental glomerulosclerosis (FSGS) are caused by mutations in genes at 1q25-31 (gene for steroid-resistant nephrotic syndrome 2 [NPHS2]), 11q21-22, 19q13 (gene for alpha-actinin 4 and NPHS1), and at additional unidentified chromosomal loci.

METHODS

We describe clinical and histopathologic features and results of linkage analysis in nine consecutive index cases with familial FSGS who, together with their families, were referred for genetic studies.

RESULTS

Two of the index cases presented in childhood (22%) and seven cases presented in adolescence or adulthood (78%). Six of their families (67%), including the two cases with childhood-onset disease, showed probable autosomal recessive inheritance. FSGS segregated at the 1q25-31 locus in two of these families and at the 11q21-22 locus in four families. None had disease caused by mutations in genes at the 19q13 locus, and no locus was identified in the three remaining families. Clinical features of proteinuria, minimal hematuria, hypertension, preeclampsia, and progressive renal impairment were usually present with autosomal recessive or dominant inheritance and with disease that segregated at the different loci. Eighteen renal biopsies from affected members of eight families showed a strong correlation between tubulointerstitial damage and percentage of obsolescent glomeruli (rho = +0.76; P < 0.01). None of the 13 patients from eight families who underwent transplantation developed recurrent FSGS in their grafts. In general, carriers of autosomal recessive disease had no distinctive clinical features apart from the development of preeclampsia in successive pregnancies.

CONCLUSION

Familial forms of FSGS are not uncommon, and presentation frequently is in adolescence or adulthood, even when inheritance is autosomal recessive. Furthermore, carriers of autosomal recessive FSGS often have no distinctive phenotype.

The safety and efficacy of granulocyte-macrophage colony-stimulating factor (Sargramostim) added to indinavir- or ritonavir-based antiretroviral therapy: a randomized double-blind, placebo-controlled trial

Sargramostim is a yeast-derived, recombinant human granulocyte-macrophage colony-stimulating factor with therapeutic potential in human immunodeficiency virus (HIV) infection. Its safety and activity when used in combination with protease inhibitors were evaluated in a randomized, double-blind trial in which 20 HIV-infected subjects on stable antiretroviral regimens, including indinavir or ritonavir, received sargramostim or placebo 3 times a week for 8 weeks. Analysis of HIV virus load excluded any 0. 5 log10 increase due to sargramostim (95% confidence interval, -0.68 to 0.44). Sargramostim was well tolerated, and inflammatory cytokines and surrogate markers of disease progression, such as serum levels of interleukin-10 and soluble tumor necrosis factor receptors types Iota and IotaIota, remained stable in subjects receiving sargramostim. Sargramostim treatment was associated with a trend toward decreased HIV RNA (>0.5 log10) and increased CD4+ cell count (>30%). These results became statistically significant only when subjects with baseline virus loads within the limits of detection or baseline CD4 cell count >50 were analyzed. No difference in indinavir pharmacokinetics was observed before or after sargramostim therapy.

CCK antagonist pre-treatment inhibits meal-enhanced drug absorption in dogs

Duodenal administration of casein and oleate increased plasma levels from oral administration of a poorly water-soluble antiepileptic drug as compared to duodenal glucose and saline in a canine model. Pre-treatment with intravenous MK-329, benzodiazepine CCK A-receptor antagonist, blocked the duodenal oleate effect on drug plasma levels in a single dog preliminary study. In a follow-up study, oral drug co-administration with Intralipid increased drug plasma levels as compared to drug co-administration with a noncaloric equivalent-volume load in seven dogs. Pre-treatment with MK-329 reduced drug plasma levels from co-administration with Intralipid toward fasted-state values. While increased drug solubility in the lipid vehicle might have been projected to account for the fed-state effect in the oral studies, the gut peptide inhibitor studies suggest that biliary secretion plays a major role in promoting the dissolution and subsequent absorption of this lipophilic drug. The data also support the hypothesis that meal-enhanced pancreatic secretion provides a greater fluid volume for drug dissolution in the small intestine. An increase in the extent of drug dissolution in the stomach, as a result of meal prolongation of gastric residence time, does not appear to contribute substantially to fed-state increases in drug plasma levels from oral drug co-administration with a lipid meal.

The effects of gamma-radiation on intestinal motor activity and faecal pellet expulsion in the guinea pig

The effects of whole-body gamma-radiation (10 Gy) on intestinal motor activity was examined in the small and large intestine of the guinea pig 18 hr post irradiation. Neurally mediated relaxations of isolated gut bath preparations were generally unaffected. However, the contractile responses to direct smooth muscle stimulation with the cholinergic muscarinic agonist carbachol or ganglionic stimulation of intrinsic cholinergic motor neurones were significantly increased in the duodenum and colon but not the jejunum. This increased sensitivity to cholinergic stimulation was reflected in an increased contractility and a shift in the concentration-response curves for carbachol. The specificity of radiation actions for cholinergic mediated contractions was further supported by the observation that histamine-evoked contractions were unaffected. In a second series of experiments we examined the effects of gamma-radiation on the rate of pellet expulsion from freshly excised colons. Both colons from irradiated animals and nonirradiated colons exposed to carbachol showed significantly faster rates of pellet expulsion, indicative of increased propulsive motility. Pretreatment of animals with 0.5 mg/kg sc of the 5HT3 receptor antagonist Granisetron prevented the effect of radiation and reduced the pellet expulsion rate to below normal. These results indicate that gastrointestinal motility disturbances seen in organ-bath preparations of the intestine from rats exposed to whole-body gamma-radiation may be related to an increased sensitivity of the cholinergic muscarinic system.

Radioprotection of chick thymus by vitamin E

One day and 7 days old male white leghorn chicks were administered vitamin E prior to their exposure to sublethal dose (2.25 Gy) of gamma radiation from 60C source. The results show that vitamin E helps in faster recovery of damage in chick thymus caused by irradiation.

Effect of radiation on some haematological parameters and its modification by vitamin E in chicks

White leghorn male chicks of 1 and 7 day age groups were studied for acute (2.25 Gy) gamma radiation (with or without vit. E pretreatment) induced haematological changes in the peripheral blood at days 1, 3, 5, 7, 14 and 28 postirradiation. A continuous decrease in the erythrocyte numbers was observed in the animals irradiated without vit. E treatment. The changes in haematocrit, haemoglobin, MCV, MCH and MCHC values were in line with the erythrocytic changes reflecting radiation induced damage to the erythroid elements. Animals pretreated with vit. E show lesser depression in the erythrocytic component at all the stages indicating its radio-protective influence. The significant increase in the immature RBC's in the peripheral blood in vit. E treated animals after irradiation, implies enhanced erythropoiesis.

Radiation induced blood pathology in chick-erythrocytes and related parameters

White leghorn male chicks at 15 days post-hatching were subjected to acute (2.10 Gy and 6.60 Gy) and fractionated (2 x 2.10 Gy) whole body gamma radiation exposure at the high dose rate of 0.60 Gy/sec to study the nature of haematological changes induced in the animals which were maintained for a maximum period of 60 days post irradiation. The investigated parameters include total red blood cell counts, haemoglobin content, haematocrit value, mean corpuscular volume and mean corpuscular haemoglobin concentration values. The results show that the haematological changes induced with 2.10 Gy and 2 x 2.10 Gy fractionated dosage are reversible and do not cause permanent damage to the erythroid characteristics. However, the system failed to recover with 6.60 Gy whole body acute exposure.

Haematocytometrical changes in chicken blood to acute 60Co gamma radiation

Newly hatched white leghorn chicks (Gallus domesticus) subjected to single whole body 2.25 Gy (225 rads) gamma radiation exposure at the dose rate of 0.50 Gy/sec (50 rads/sec), were studied for changes in a number of haematological parameters at days 1,3,5,7,14 and 28 post irradiation during development. The sudden decline and gradual recovery in total RBC and WBC counts and the level of Hb and Hct along with MCV, MCH and MCHC values evaluation indicates a high regenerative capability of leghorn chicks.