Interactions between integrin α9β1 and VCAM-1 promote neutrophil hyperactivation and mediate poststroke DVT

ABSTRACT

Venous thromboembolic events are significant contributors to morbidity and mortality in patients with stroke. Neutrophils are among the first cells in the blood to respond to stroke and are known to promote deep vein thrombosis (DVT). Integrin α9 is a transmembrane glycoprotein highly expressed on neutrophils and stabilizes neutrophil adhesion to activated endothelium via vascular cell adhesion molecule 1 (VCAM-1). Nevertheless, the causative role of neutrophil integrin α9 in poststroke DVT remains unknown. Here, we found higher neutrophil integrin α9 and plasma VCAM-1 levels in humans and mice with stroke. Using mice with embolic stroke, we observed enhanced DVT severity in a novel model of poststroke DVT. Neutrophil-specific integrin α9-deficient mice (α9fl/flMrp8Cre+/-) exhibited a significant reduction in poststroke DVT severity along with decreased neutrophils and citrullinated histone H3 in thrombi. Unbiased transcriptomics indicated that α9/VCAM-1 interactions induced pathways related to neutrophil inflammation, exocytosis, NF-κB signaling, and chemotaxis. Mechanistic studies revealed that integrin α9/VCAM-1 interactions mediate neutrophil adhesion at the venous shear rate, promote neutrophil hyperactivation, increase phosphorylation of extracellular signal-regulated kinase, and induce endothelial cell apoptosis. Using pharmacogenomic profiling, virtual screening, and in vitro assays, we identified macitentan as a potent inhibitor of integrin α9/VCAM-1 interactions and neutrophil adhesion to activated endothelial cells. Macitentan reduced DVT severity in control mice with and without stroke, but not in α9fl/flMrp8Cre+/- mice, suggesting that macitentan improves DVT outcomes by inhibiting neutrophil integrin α9. Collectively, we uncovered a previously unrecognized and critical pathway involving the α9/VCAM-1 axis in neutrophil hyperactivation and DVT.

Amino Acid Metabolism and Atherosclerotic Cardiovascular Disease

Despite significant advances in medical treatments and drug development, atherosclerotic cardiovascular disease (ASCVD) remains a leading cause of death worldwide. Dysregulated lipid metabolism is a well-established driver of ASCVD. Unfortunately, even with potent lipid-lowering therapies, ASCVD-related deaths have continued to increase over the past decade, highlighting an incomplete understanding of the underlying risk factors and mechanisms of ASCVD. Accumulating evidence over the past decades indicates a correlation between amino acids and disease state. This review explores the emerging role of amino acid metabolism in ASCVD, uncovering novel potential biomarkers, causative factors, and therapeutic targets. Specifically, the significance of arginine and its related metabolites, homoarginine and polyamines, branched-chain amino acids, glycine, and aromatic amino acids, in ASCVD are discussed. These amino acids and their metabolites have been implicated in various processes characteristic of ASCVD, including impaired lipid metabolism, endothelial dysfunction, increased inflammatory response, and necrotic core development. Understanding the complex interplay between dysregulated amino acid metabolism and ASCVD provides new insights that may lead to the development of novel diagnostic and therapeutic approaches. Although further research is needed to uncover the precise mechanisms involved, it is evident that amino acid metabolism plays a role in ASCVD.

Chitosan/alginate nanogel potentiate berberine uptake and enhance oxidative stress mediated apoptotic cell death in HepG2 cells

Biopolymer-based nanoscale drug delivery systems have become a promising approach to overcome the limitations associated with conventional chemotherapeutics used for cancer treatment. Herein, we reported to develop a hydrophilic nanogel (NG) composed of Chitosan (Chi) and sodium alginate (Alg) using the ion gelation method for delivering Berberine hydrochloride (BBR), an alkaloid obtained from Berberis aristata roots. The use of different nanocarriers for BBR delivery has been reported previously, but the bioavailability of these carriers was limited due to phagocytic uptake and poor systemic delivery. The developed NG showed enhanced stability and efficient entrapment of BBR ∼92 %, resulting in a significant increase in bioavailability. The pH-dependent release behavior demonstrated sustained and effective release of ∼86 %, ∼74 % and, ∼53 % BBR at pH 5.5, 6.6, and 7.4 respectively after 72h, indicating its potential as a drug carrier. Additionally, the cellular uptake of BBR was significantly higher ∼19 % in the BBR-NG (25 μM) than in bulk BBR (100 μM), leading to enhanced ROS generation, mitochondrial depolarisation, and inhibition of cell proliferation and colony formation in HepG2 cells. In summary, the results suggest that the Chi/Alg biopolymer-based nano-formulation could be an effective approach for delivering BBR and enhancing its cellular uptake, efficacy, and cytotoxicity.

CD14 Blockade Does Not Improve Outcomes of Deep Vein Thrombosis Following Inferior Vena Cava Stenosis in Mice

Background

Neutrophil-mediated persistent inflammation and neutrophil extracellular trap formation (NETosis) promote deep vein thrombosis (DVT). CD14, a co-receptor for toll-like receptor 4 (TLR4), is actively synthesized by neutrophils, and the CD14/TLR4 signaling pathway has been implicated in proinflammatory cytokine overproduction and several aspects of thromboinflammation. The role of CD14 in the pathogenesis of DVT remains unclear.

Objective

To determine whether CD14 blockade improves DVT outcomes.

Methods

Bulk RNA sequencing and proteomic analyses were performed using isolated neutrophils following inferior vena cava (IVC) stenosis in mice. DVT outcomes (IVC thrombus weight and length, thrombosis incidence, neutrophil recruitment, and NETosis) were evaluated following IVC stenosis in mice treated with a specific anti-CD14 antibody, 4C1, or control antibody.

Results

Mice with IVC stenosis exhibited increased plasma levels of granulocyte colony-stimulating factor (G-CSF) along with a higher neutrophil-to-lymphocyte ratio and increased plasma levels of cell-free DNA, elastase, and myeloperoxidase. Quantitative measurement of total neutrophil mRNA and protein expression revealed distinct profiles in mice with IVC stenosis compared to mice with sham surgery. Neutrophils of mice with IVC stenosis exhibited increased inflammatory transcriptional and proteomic responses, along with increased expression of CD14. Treatment with a specific anti-CD14 antibody, 4C1, did not result in any significant changes in the IVC thrombus weight, thrombosis incidence, or neutrophil recruitment to the thrombus.

Conclusion

The results of the current study are important for understanding the role of CD14 in the regulation of DVT and suggest that CD14 lacks an essential role in the pathogenesis of DVT following IVC stenosis.

Serine synthesis via reversed SHMT2 activity drives glycine depletion and acetaminophen hepatotoxicity in MASLD

Metabolic dysfunction-associated steatotic liver disease (MASLD) affects one-third of the global population. Understanding the metabolic pathways involved can provide insights into disease progression and treatment. Untargeted metabolomics of livers from mice with early-stage steatosis uncovered decreased methylated metabolites, suggesting altered one-carbon metabolism. The levels of glycine, a central component of one-carbon metabolism, were lower in mice with hepatic steatosis, consistent with clinical evidence. Stable-isotope tracing demonstrated that increased serine synthesis from glycine via reverse serine hydroxymethyltransferase (SHMT) is the underlying cause for decreased glycine in steatotic livers. Consequently, limited glycine availability in steatotic livers impaired glutathione synthesis under acetaminophen-induced oxidative stress, enhancing acute hepatotoxicity. Glycine supplementation or hepatocyte-specific ablation of the mitochondrial SHMT2 isoform in mice with hepatic steatosis mitigated acetaminophen-induced hepatotoxicity by supporting de novo glutathione synthesis. Thus, early metabolic changes in MASLD that limit glycine availability sensitize mice to xenobiotics even at the reversible stage of this disease.

STE20-type kinases MST3 and MST4 promote the progression of hepatocellular carcinoma: Evidence from human cell culture and expression profiling of liver biopsies

Hepatocellular carcinoma (HCC) is one of the most fatal and fastest growing malignancies. Recently, nonalcoholic steatohepatitis (NASH), characterized by liver steatosis, inflammation, cell injury (hepatocyte ballooning), and different stages of fibrosis, has emerged as a major catalyst for HCC. Because the STE20-type kinases, MST3 and MST4, have been described as critical molecular regulators of NASH pathophysiology, we here focused on determining the relevance of these proteins in human HCC. By analyzing public datasets and in-house cohorts, we found that hepatic MST3 and MST4 expression was positively correlated with the incidence and severity of HCC. We also found that the silencing of both MST3 and MST4, but also either of them individually, markedly suppressed the tumorigenesis of human HCC cells including attenuated proliferation, migration, invasion, and epithelial-mesenchymal transition. Mechanistic investigations revealed lower activation of STAT3 signaling in MST3/MST4-deficient hepatocytes and identified GOLGA2 and STRIPAK complex as the binding partners of both MST3 and MST4. These findings reveal that MST3 and MST4 play a critical role in promoting the progression of HCC and suggest that targeting these kinases may provide a novel strategy for the treatment of liver cancer.

Inhibition of MAP4K4 Signaling Initiaties Metabolic Reprogramming to Protect Hepatocytes from Lipotoxic Damage

The primary hepatic consequence of obesity is non-alcoholic fatty liver disease (NAFLD), affecting about 25% of the global adult population. Non-alcoholic steatohepatitis (NASH) is a severe form of NAFLD characterized by liver lipid accumulation, inflammation, and hepatocyte ballooning, with a different degree of hepatic fibrosis. In the light of rapidly increasing prevalence of NAFLD and NASH, there is an urgent need for improved understanding of the molecular pathogenesis of these diseases. The aim of this study was to decipher the possible role of STE20-type kinase MAP4K4 in the regulation of hepatocellular lipotoxicity and susceptibility to NAFLD. We found that MAP4K4 mRNA expression in human liver biopsies was positively correlated with key hallmarks of NAFLD (i.e., liver steatosis, lobular inflammation, hepatocellular ballooning, and fibrosis). We also found that the silencing of MAP4K4 suppressed lipid deposition in human hepatocytes by stimulating β-oxidation and triacylglycerol secretion, while attenuating fatty acid influx and lipid synthesis. Furthermore, downregulation of MAP4K4 markedly reduced the glycolysis rate and lowered incidences of oxidative/endoplasmic reticulum stress. In parallel, we observed suppressed JNK and ERK and increased AKT phosphorylation in MAP4K4-deficient hepatocytes. Together, these results provide the first experimental evidence supporting the potential involvement of STE20-type kinase MAP4K4 as a component of the hepatocellular lipotoxic milieu promoting NAFLD susceptibility.

STE20-type kinase TAOK3 regulates hepatic lipid partitioning

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD), defined by excessive lipid storage in hepatocytes, has recently emerged as a leading global cause of chronic liver disease. The aim of this study was to examine the role of STE20-type protein kinase TAOK3, which has previously been shown to associate with hepatic lipid droplets, in the initiation and aggravation of human NAFLD.

METHODS

The correlation between TAOK3 mRNA expression and the severity of NAFLD was investigated in liver biopsies from 62 individuals. In immortalized human hepatocytes, intracellular fat deposition, lipid metabolism, and oxidative and endoplasmic reticulum stress were analyzed when TAOK3 was overexpressed or knocked down by small interfering RNA. Subcellular localization of TAOK3 was characterized in human and mouse hepatocytes by immunofluorescence microscopy.

RESULTS

We found that the TAOK3 transcript levels in human liver biopsies were positively correlated with the key lesions of NAFLD (i.e., hepatic steatosis, inflammation, and ballooning). Overexpression of TAOK3 in cultured human hepatocytes exacerbated lipid storage by inhibiting β-oxidation and triacylglycerol secretion while enhancing lipid synthesis. Conversely, silencing of TAOK3 attenuated lipid deposition in human hepatocytes by stimulating mitochondrial fatty acid oxidation and triacylglycerol efflux while suppressing lipogenesis. We also found aggravated or decreased oxidative/endoplasmic reticulum stress in human hepatocytes with increased or reduced TAOK3 levels, respectively. The subcellular localization of TAOK3 in human and mouse hepatocytes was confined to intracellular lipid droplets.

CONCLUSIONS

This study provides the first evidence that hepatic lipid droplet-coating kinase TAOK3 is a critical regulatory node controlling liver lipotoxicity and susceptibility to NAFLD.

Phytochemical profiling and cytotoxic evaluation of Premna serratifolia L. against human liver cancer cell line

Premna serratifolia L. (Lamiaceae) is a medicinal plant, widely distributed in the tropical and subtropical regions and commonly used in traditional medicine. The current study was focused to evaluate the cytotoxic potential of aqueous extract of root of P. serratifolia (AEPS) against human hepatoblastoma cancer cell line (Hep G2).The yield of the dried extract was 5.8% and used for further studies.Cytotoxic potential of AEPS was analyzed by MTT assay, which exhibits IC50 value 1000 µg/mL after 48 h incubation. Hoechst and AO/EtBr staining, ROS measurement, mitochondrial membrane potential, clonogenic and wound healing assays also confirmed the cytotoxic efficacy of AEPS in dose and time-dependent manner. UPLC-Q-TOF-MS/MS analysis of AEPS confirmed the presence of 12polyphenolic compounds, namely 4-hydroxy-3-methoxycinnamic acid, linarin, peonidin-3,5-O-di-beta-glucopyranoside, diosmin, trans-cinnamic acid, daidzein, saponarin, homoorietin, acacetin, sarsasapogenin, phytol and sissotrin. The cytotoxic potential of AEPS might due to presence of biologically active polyphenolic compounds.

Quorum sensing and expression of virulence in Escherichia coli O157:H7

Enterohaemorrhagic Escherichia coli O157:H7 causes a characteristic histopathology in intestinal cells known as attaching and effacing lesion. The genes for the lesion are encoded by the Locus of Enterocyte Effacement (LEE) pathogenicity island, that encodes a type III secretion system, the intimin intestinal colonization factor, and the translocated intimin receptor protein that is translocated from the bacterium to the host epithelial cells. Expression of the operons encoded within LEE is complex, but recent studies have demonstrated that quorum sensing influences transcription from four of the LEE operon promoters. A transcriptional regulator (LuxR homologue), signal synthase (LuxI homologue), and autoinducer (acylhomoserine lactone) are indispensable for this system in most gram-negative bacteria. Vibrio harveyi, a gram-negative bioluminescent marine bacterium, regulates light production in response to two autoinducers (AI-1 and AI-2). AI-1 is a homoserine lactone produced by most gram-negative bacteria. The structure of AI-2 is not known, but many species of gram positive and gram-negative bacteria, including E. coli and more specifically O157:H7, have been shown to produce AI-2 depending on the function encoded by the luxS gene. The LuxS acts as an AI-2 synthase and the AI-2 is produced from S-adenosylmethionine in three enzymatic steps. The substrate for LuxS is S-ribosylhomocysteine, which is cleaved to form two products, one of which is homocysteine, and the other is AI-2. The biosynthetic pathways and the biochemical intermediates in AI-2 biosynthesis have been observed to be identical in several gram-negative bacteria, such as E. coli, Salmonella typhimurium, V. harveyi, Vibrio cholerae, and Enterococcus faecalis. Thus, unlike quorum sensing via the family of related homoserine autoinducers, AI-2 is a universal signal, which may be used by a variety of bacteria for communication among and between species and may be responsible for regulation of virulence genes in E. coli O157:H7.

Repair and recovery of thermally injured cells of Yersinia enterocolitica in milk

One standard strain of the organism MTCC-861 and the two culture isolates VRW-22 and CRW-15 were exposed to batch pasteurization (62.8 degrees C for 30 min) in brain heart infusion broth, skim milk, and whole milk. The trials were repeated three times. None of the isolates survived pasteurization treatment. However, the studies were further directed toward the repair and recovery of thermally injured cells, if any, in peptone sorbitol bile broth, skim milk, and whole milk. The results revealed that only a low number of test cultures were recovered in peptone sorbitol bile broth after 8 days of incubation at 10 degrees C. On the other hand, the recovery was still slower in skim and whole milk, with a detection of the test isolates only on 10 days of incubation under similar conditions.

Significance of microbial biofilms in food industry: a review

Biofilms have been of considerable interest in the context of food hygiene. Of special significance is the ability of microorganisms to attach and grow on food and food-contact surfaces under favourable conditions. Biofilm formation is a dynamic process and different mechanisms are involved in their attachment and growth. Extracellular polymeric substances play an important role in the attachment and colonization of microorganisms to food-contact surfaces. Various techniques have been adopted for the proper study and understanding of biofilm attachment and control. If the microorganisms from food-contact surfaces are not completely removed, they may lead to biofilm formation and also increase the biotransfer potential. Therefore, various preventive and control strategies like hygienic plant lay-out and design of equipment, choice of materials, correct use and selection of detergents and disinfectants coupled with physical methods can be suitably applied for controlling biofilm formation on food-contact surfaces. In addition, bacteriocins and enzymes are gaining importance and have an unique potential in the food industry for the effective biocontrol and removal of biofilms. These newer biocontrol strategies are considered important for the maintenance of biofilm-free systems, for quality and safety of foods.

Airway simulation to guide stent placement for tracheobronchial obstruction in lung cancer

BACKGROUND

To effectively palliate large airway obstruction in advanced unresectable lung cancer (stage IIIB or IV), we developed an airway imaging technique to guide selective endobronchial metallic stent placement.

METHODS

Fourteen consecutive patients with severe dyspnea (American Thoracic Society grade 4) had a combination of fiberoptic bronchoscopy, chest roentgenography, computed tomographic scanning, helical computed tomography with three-dimensional reconstruction, and intraluminal bronchography with selective bronchial guidewire placement under fluoroscopy to visually reconstruct and simulate the abnormal airway before and during stent placement. Wallstent or Gianturco intraluminal stents were used alone or in combination (up to five stents) to establish patency of the distal trachea and the major bronchi.

RESULTS

All 14 patients had successful deployment with initial relief of airway stenosis (>75% predicted diameter). No procedural complications were noted. However, technical problems included stent foreshortening and imprecision of placement, misinterpretation of bronchography (mucous versus tumor), and airway maintenance during manipulation. Length of stay attributable to the procedure averaged 4 days. Stent placement initially improved the dyspnea score in 7 of 14 patients. Five of 14 died in less than 1 month, with the remainder alive at up to 8 months' follow-up. Of those surviving more than 1 month, the Karnofsky score improved in 4 and was unchanged in 5, with 2 dependent (Karnofsky score <50), 3 functional (Karnofsky score, 50 to 70), and 4 active (Karnofsky score >70).

CONCLUSIONS

A protocol combining helical computed tomography with three-dimensional reconstruction, bronchography, and bronchoscopy allows accurate assessment of malignant airway obstruction to facilitate intralumenal stent placement for relief of stenosis. Patient selection to favor effective palliation and cost effectiveness has yet to be defined.

The effect of chronic furosemide administration on urinary calcium excretion and calcium balance in growing rats

The study was designed to determine the calciuretic effect of furosemide and its impact upon calcium balance during chronic (25 days) furosemide administration to growing rats. Experiments were performed on 18 six-wk-old rats. Nine animals received furosemide, and 9 served as controls. The administration of furosemide in a dose of 40 mg resulted in a significant increase in calcium excretion in the treated group; urinary calcium excretion almost doubled that of the controls during the first 24-hr collection (3.74 +/- 0.44 mg in the treated animals compared with 1.90 +/- 0.15 mg in the controls; P less than 0.05). The average daily urinary calcium excretion during each of four subsequent 6-day periods remained approximately three-fold higher in animals which received furosemide compared with controls (P less than 0.001 for each 6-day period). The furosemide-induced increase in urinary calcium excretion did not diminish with time. Sodium excretion did not significantly increase either acutely or chronically in response to furosemide. Daily urinary volume increased approximately 40 to 60% in the furosemide-treated group compared with that of the controls (P less than 0.001). The cumulative calcium balance in the control group exceeded by 7% that of the furosemide-treated animals [2696.3 +/- 20.8 mg versus 2518.6 +/- 20.1 mg (P less than .001]. The findings indicate that distal nephron compensatory mechanisms effecting sodium conservation following furosemide do not result in similar conservation of calcium. Calcium balance may be deleteriously affected.

Congenital nephrogenic diabetes insipidus in a baby girl

A 6-week-old girl with fever, hypernatraemia, dehydration, and polyuria failed to concentrate urine in response to exogenous vasopressin administration. There was no family history of nephrogenic diabetes insipidus. When she was 15 months old, the infusion of vasopressin did not produce an increase in urinary cyclic-AMP.

A profile of health sciences libraries in Southeast Asia

This paper reports the results of a survey undertaken by the World Health Organization of health sciences libraries in Southeast Asia. It includes information on clientele, budget, personnel, collections, lending policy, dissemination of information, and reference services. The survey indicates that the collections in most of the health sciences libraries in Southeast Asia are deficient and that services provided to readers are inadequate. Recommendations for improvement are outlined.

Acute renal failure in newborn infants

The clinical course and follow-up of 14 neonates who developed acute renal failure are reported. Renal failure in these patients was secondary to major perinatal disorders, e.g., hyaline membrane disease, pneumonia, hemorrhage, or sepsis. Thirteen patients had hypoxia and nine were in shock when renal failure developed. Five patients died during the acute stage of renal failure. Of nine survivors, five patients sustained residual renal damage.

Neonatal renal papillary and cortical necrosis

Renal papillary and cortical necrosis (RPCN) in newborn infants has been generally fatal. This report describes three survivors of neonatal RPCN who have been followed up from 23 to 57 months. The cause of RPCN was hemorrhage and asphyxia neonatorum in two patients and hemorrhage and shock in one. The diagnosis was confirmed in one patient by an excretory urogram at 3 weeks of age and in another by renal biopsy at 5 weeks of age. In the third, diagnosis was made retrospectively. Findings from subsequent examination showed that creatinine clearance was normal in one patient, slightly reduced in another, and moderately reduced in the third. Maximum ability to concentrate urine was decreased in all. Follow-up excretory urograms in all three patients showed dilated bizarre-appearing calices and renal cortical atrophy. These radiologic findings are similar to those found in segmental hypoplasia or chronic (atrophic) pyelonephritis.

Unusual manifestations of Henoch-Schönlein syndrome

Henoch-Schönlein syndrome represents a diagnostic challenge when the abdominal and/or joint manifestations precede the cutaneous lesions. Laparotomy is often performed unnecessarily. We describe a patient whose abdominal symptoms antedated the appearance of cutaneous lesions by three months. Gastrointestinal blood loss, thrombocytosis, hypoproteinemia, and the roentgenographic appearance of the small intestine suggested the correct diagnosis. His course was further complicated by hypertension associated with elevated plasma renin levels without evidence of nephritis. Joint manifestations were mild and transient as were testicular pain and swelling.

Pseudohypoaldosteronism due to sweat gland dysfunction

Pseudohypoaldosteronism is an uncommon disorder characterized by urinary sodium wasting and is attributed to a defect in distal renal tubular sodium handling with failure to respond to endogenous aldosterone. Sweat electrolyte values in other reported patients, when measured, have been normal. A 3.5-year-old girl developed repeated episodes of dehydration, hyponatremia, and hyperkalemia during the first 19 months of life. Serum sodium was as low as 113 mEq/liter and potassium as high as 11.1 mEq/liter. Her plasma and urinary aldosterone levels were persistently elevated (Figs. 1-4). Unlike patients with classic pseudohypoaldosteronism she demonstrated no urinary sodium wasting (Figs. 2 and 3). During episodes of hyponatremia and reduced sodium intake her urinary sodium was less than 5 mEq/liter. In addition, her sweat sodium concentration was consistently above 125 mEq/liter and salivary sodium concentration above 58 mEq/liter. Her chest x-ray, 72-hr fecal fat excretion, serum and urinary pancreatic amylase (amy-2) were normal, providing no evidence for cystic fibrosis. It is proposed that this patient represents a new variant of pseudohypoaldosteronism with excessive loss of sodium from the sweat and salivary glands instead of the kidneys.

Extracapillary proliferative glomerulonephritis in children

The clinical course and renal pathology of 17 children with acute extracapillary proliferative glomerulonephritis is reported. Patients with systemic diseases associated with renal involvement were excluded. The onset followed streptococcal infection in ten; of these, four have died, one has been transplanted, and the remaining five have completely healed. The mean follow-up of the latter five patients was 32 months (range, 18 to 57 months). Of the other seven patients without evidence of precedeing streptococcal infection, two have died, two have been transplanted, and the remaining three all have hypertension, proteinuria, and reduced creatinine clearance. The mean follow-up of the latter three patients was 29 months (range, 14 to 38 months). The initial renal histopathologic changes and their progress in later renal biopsies is described. The role of various therapeutic agents is discussed. The prognosis in acute extracapillary proliferative glomerulonephritis following streptococcal infection appears to be better than in ones without preceding streptococcal infection.

Polycystic disease and hepatic fibrosis in children. Renal function studies

Renal function studies were done in five children with infantile polycystic disease (IPCD)of kidneys and liver and in four with congenital hepatic fibrosis (CHF). Glomerular filtration rate was reduced in all IPCD patients and in two of four CHF patients. Urinary concentrating ability following water deprivation and vasopressin administration was impaired in all IPCD patients and in three of four CHF patients. During control period, all patients had asymptomatic metabolic acidosis with total carbon dioxide content less than or equal to 20.5 millimols/liter, and net acid excretion (NAE) was reduced in all but one. Ammonium chloride was administered to seven patients; NAE increased in all, but the increments were subnormal in four. The inability to excrete maximally concentrated urine and an adequate amount of net acid may best be explained by abnormal tubular structure or alterations in medullary architecture secondary to progressive scarring, or both.