beta-Mercaptolactate cysteine disulfiduria in two normal sisters. Isolation and characterization of beta-mercaptolactate cysteine disulfide

β-Mercaptolactate cysteine disulfide (βMLCD) was detected in two mentally normal sisters, 11 and 13 years old. After isolation by ion-exchange chromatography, high-voltage electrophoresis, and adsorption chromatography on Porapak Q, βMLCD was identified by mass spectrometry of its following methyl ester derivatives: O, N-di-trifluoracetyl, O-trifluracetyl-N-dinitrophenyl, O, N-diacetyl, and O-acetyl-N-dinitrophenyl, with acetyl groups 50% perdeuterated, as well as by gas chromatography-mass spectrometry combination of the desulfuration products alanine (as N-trifluotacetyl-methy; ester) and lactic acid (as methyl ester). The isolated βMLCD contained no sulfoxide nor sulfone and exhibited an UV spectrum closely related to cystine. In urine the concentration range of βMLCD was 345–751 μmole/1 (n=5) and 54–133 mg/g creatinine; in plasma a trace of βMLCD could be detected only in one case. Oral administration of L-cysteine or L-methionine elevated the concentration of βMLCD in urine and in plasma. A further disulfide accompanying βMLCD in urine was isolated and identified as thioglycolate cysteine disulfide.     

Preliminary Study on the Role of Virtual Touch Tissue Quantification Combined with a Urinary β2-Microglobulin Test on the Early Diagnosis of Gouty Kidney Damage

The goal of the work described here was to evaluate the role of virtual touch tissue quantification (VTQ) combined with urinary β2-microglobulin (β2-MG) measurement in the early diagnosis of gouty kidney damage. Two hundred fifty-nine patients with gouty kidney damage and 200 healthy control subjects were tested. The shear wave velocity (SWV) of the renal parenchyma and sinus as determined with VTQ and the urinary β2-MG level of the two groups were analyzed. Although there were no significant differences in age, body mass index, creatinine level and blood urea nitrogen between the two groups (all p's > 0.05), the aforementioned parameters were higher in the group with gouty kidney damage than in the control group. Urinary β2-MG levels of the patients with kidney damage were significantly higher than those of the control subjects (t = 6.38, p < 0.01). The SWV of the renal parenchyma was higher than that of the sinus in both groups. Compared with controls, patients with kidney damage had significantly increased renal parenchyma and sinus SWVs (all p-values < 0.05). Urinary β2-MG level was positively linearly correlated with the SWV of renal parenchyma in patients with kidney damage (r = 0.442, p < 0.0001). However, there was no correlation between urinary β2-MG level and the SWV of the sinus in patients with kidney damage (r = 0). In the control group, there was no correlation between urinary β2-MG level and the SWV of the renal parenchyma or sinus. The elasticity of the kidney as determined with VTQ, combined with the urinary β2-MG level, may be helpful in the early diagnosis of gouty kidney damage.     

Urinary lysosomal glycosidases after renal allotransplantation: correlation of enzyme excretion with allograft rejection and ischemia

Urinary β-galactosidase, β-glucuronidase and N-acetyl-β-glucosaminidase were measured in patients with renal allotransplants and compared with normal controls. Increased excretion of all three enzymes was noted in the transplant patients resulting possibly from mild chronic rejection.A second part of the investigation correlated renal function with daily N-acetyl-β-glucosaminidase excretion by the patients. In acute rejection, enzyme levels rose sharply from a baseline then decreased following successful treatment. With cadaveric grafts and initially good urinary flow, N-acetyl-β-glucosaminidase levels were high and decreased as creatinine clearance improved; however, with initial oliguria, levels were low and rose as diuresis began then decreased to a baseline. This was attributed to a washing out of enzyme released during the unavoidable ischemic period involved in handling cadaver kidneys.Because it reflects physiological changes in the kidney, daily monitoring of urinary N-acetyl-β-glucosaminidase should be helpful in the diagnosis of renal damage caused by rejection and ischemia.     

Beta-N-acetylhexosaminidase in the urine, kidney and serum of bromobenzene-intoxicated mice.

beta-N-Acetylhexosaminidase isoenzymes were separated from the kidney, serum and urine of normal mice and mice intoxicated with bromobenzene, using DEAE-cellulose chromatography. Both mouse serum and urine showed hexosaminidase profiles similar to the human counterparts with the presence of B (basic), I (intermediate) and A (acidic) isoenzymes. A notable feature was the presence of a high proportion of an intermediate form in mouse urine which is not always present in human urine. Hexosaminidase activity increased significantly in urine of mice intoxicated with bromobenzene. Its increase was time-dependent and due to kidney damage with a release in the urine of hexosaminidase A, I and, in higher proportion, B. No significant differences were observed in mouse kidney and serum profiles following intoxication with bromobenzene. The total activity of hexosaminidase, using 4-methylumbelliferyl-2-acetamido-2-deoxy-beta-D-glucopyranoside as substrate, did not increase in the serum of mice intoxicated with bromobenzene. Both hexosaminidase activity and the isoenzyme pattern in urine can be used as indicators of kidney damage by bromobenzene intoxication.     

Urine activity of cathepsin B,collagenase and urine excretion of TGF-β 1 and fibronectin in membranous glomerulonephritis

In 30% of cases nephrotic syndrome is caused by membranous glomerulonephritis (MG). Protein accumulation in glomeruli leads to progressive loss of kidney function and damage of structure in MG. The role of tissue proteolytic systems and growth factors in this process is not known. The purpose of the study was to estimate urine cathepsin B, collagenase activity and urine excretion of TGF-β ₁ and fibronectin in MG. Cathepsin B activity was greater in the urine of MG patients than in the control group (10.58±8.73 pmol AMC/mg creatinine per min^?1 vs control 7.11±2.05 pmol AMC/mg creatinine per min^?1; P<0.05). Urine collagenase activity was higher in the group of patients than in the control group (8.59±4.26 pmol AMC/ mg creatinine per min^?1 vs control 3.84±2.09 pmol AMC/ mg creatinine per min^?1 P<0.02). Urine excretion of fibronectin (45.60 ng/mg creatinine vs control 10.30 ng/mg creatinine; P<0.04) and TGF-β ₁ levels in the urine were higher than in controls (283.55±248.13 pg/ml vs 36.11±48.01 pg/ml; P<0.01). Results suggest glomerular overproduction of TGF-β ₁ and urinary leak of proteolytic enzymes (PE). This may result in decreased glomerular PE activity in MG and, with time, may lead to protein accumulation in renal glomeruli and to progressive loss of kidney function and damage of structures as the course of MG progresses. PE urine composition as well as ECM protein and cytokine urine excretion may alow noninvasive glomerulopathy course monitoring in humans in the future.     

Activity of beta-galactosidase, beta-glucuronidase and N-acetyl-beta-glucosaminidase in human rectal mucosa

Activity of β-galactosidase, β-glucuronidase and N-acetl-β-glucosaminidase was determined by biopsy specimens of rectal mucosa of control subjects, cystinotic children and their parents.The studied enzymes exhibited maximal activity at pH 5.0, 4.0 and 4.5, respectively. Apparent K_m values using P-nitrophenyl-β-galactoside, p-nitrophenyl-β-glucuronide and p-nitropheny-β-glucosaminide were found to be 0.52 mM, 0.70 mM, and 0.67 mM.The activity of all three enzymes was found to be closely correlated in the 11 subjects of the control group. The values found in parents and their cystinotic children fit into these correlations, but show higher scatter of data caused by the fact that values of β-galactosidase were found to be higher and of β-glucuronidase and N-acetyl-glucosaminidase lower in the group of parents than in the other two groups.     

N-Acetyl β-d-glucosaminidase and α-l-fucosidase activities in relation to glycosylated hemoglobin levels and to retinopathy in diabetes

N-Acetyl β-d-glucosaminidase and α-l-fucosidase were determined in human sera from 25 control subjects, in 23 diabetic patients without retinopathy and in 22 diabetic patients with retinopathy.The results show significantly higher N-acetyl β-d-glucosaminidase activity in diabetic patients independently of the development of retinopathy and also independently of the length of diabetes. No correlation was found between either serum enzymes and serum glucose concentration and glycosylated hemoglobin (HbA,).     

Detection of Fabry hemizygotes and heterozygotes by measurement of -galactosidase in urine

The determination of α-galactosidase in urine can be used as a simple method for the diagnosis of Fabry hemizygotes. The activity of this enzyme was related to that of N-acetyl-β-glucosaminidase. The ratio N-acetyl-β-glucosaminidase/α-galactosidase in urine was relatively constant in any one individual. In the control group, the mean value of this ratio was 7.4 (range 1.2–20.5). In Fabry hemizygotes (n = 6) the ratio was 50 or higher. Three types of carriers could be recognized, with high (n = 1), intermediate (n = 2) and normal (n = 3) values, so that with this procedure some of the carriers are detected.     

The quantitation of beta-aminoisobutyric acid in urine by mass fragmentography

A specific, rapid and sensitive method for the quantitation of β-aminoisobutyric acid in urine is described. The method is based on the analysis by quadrupole mass fragmentography of its N-TFA-O-n-butyl derivative using α-amino octanoic acid as an internal standard. The procedure is sensitive being able to quantitate as little as 1 ng of β-aminoisobutyric acid and is applicable to the routine analysis of this compound in biological fluids. The analysis time, exclusive of chemical derivatization, occupies about 17 minutes.     

Purification and Characterization of a Human Neutrophil Neutral Protease: THE NEUTRAL PEPTIDE-GENERATING PROTEASE

A human neutrophil neutral protease which generates a low molecular weight peptide from a plasma protein substrate and cleaves the basic amino acid ester substrates α-N-p-tosyl-l-arginine methyl ester HCl, α-N-benzoyl-l-arginine-methyl ester HCl, and α-N-carbobenzoxy-l-lysine-p-nitrophenyl ester has been purified to homogeneity and distinguished from the known lysosomal neutrophil proteases. The starting activity was obtained from purified human neutrophils by homogenization, sedimentation by low-speed centrifugation, and high salt elution of the insoluble material. Purification was achieved by aprotinin-affinity chromatography, precipitation at low ionic strength, and gel filtration. The overall recovery, relative to the activity in the starting eluate of the neutrophil fraction, was 50% with a 200- to 400-fold increase in specific activity. After treatment with diisopropylfluorophosphate to eliminate autodegradation, sodium dodecyl sulfate-polyacrylamide gel electrophoresis of reduced and unreduced protein gave a single protein band of 29,000-30,000 mol wt. The isoelectric point determined in sucrose gradients ranged from pH 7.8 to 8.3 with a peak at pH 8.0. This neutrophil protease, like cathepsin G and elastase, is composed of a single polypeptide chain of 30,000 mol wt, but differs from cathepsin G and elastase in its less cationic isoelectric point and its failure to cleave synthetic substrates presenting an aromatic amino acid ester linkage and alanyl peptide bonds, respectively.     

Evaluating the utility of N1,N12-diacetylspermine and N1,N8-diacetylspermidine in urine as tumor markers for breast and colorectal cancers

BackgroundAmong natural polyamines, the concentrations of the diacetylated form of spermine and spermidine increase in the urine of patients with cancer. We evaluated the utility of urinary N¹,N¹²-diacetylspermine (DiAcSpm) and N¹,N⁸-diacetylspermidine (DiAcSpd) as tumor markers for breast and colorectal cancers.MethodsUrinary DiAcSpm and DiAcSpd concentrations were measured by an enzyme-linked immunosorbent assay. Urine and serum samples were collected from 33 and 28 patients with colorectal and breast cancers, respectively. The sensitivity of urine samples to DiAcSpm and DiAcSpd concentrations was compared with serum concentrations of carcinoembryonic antigen (CEA) and carbohydrate antigen CA 15-3 in breast cancer patients and with serum concentrations of CEA and CA 19-9 in colorectal cancer patients, respectively.ResultsIn breast cancer patients, the sensitivity of DiAcSpm and DiAcSpd was 46.4% and 14.2%, respectively, which was higher than that of CEA and CA 15-3. In patients with colorectal cancer, the sensitivity of DiAcSpm and DiAcSpd was 69.6% and 36.3%, respectively. CEA was the second sensitive marker and CA 19-9 was the least sensitive marker in these patients.ConclusionDiAcSpm is a highly sensitive tumor marker. DiAcSpm can serve as a powerful tool in settings such as initial screening for cancers in routine health examination.     

The Effects of n-3 Long-Chain Polyunsaturated Fatty Acid Supplementation on Biomarkers of Kidney Injury in Adults With Diabetes: Results of the GO-FISH trial

OBJECTIVE

Long-chain n-3 polyunsaturated fatty acid (n-3 PUFA) supplements may have renoprotective effects in patients with diabetes, but previous trials have been inconsistent. We performed a randomized controlled trial of n-3 PUFA supplementation on urine albumin excretion and markers of kidney injury in adults with type 2 diabetes.

RESEARCH DESIGN AND METHODS

We conducted a randomized, placebo-controlled, two-period crossover trial to test the effects of 4 g/day of n-3 PUFA supplementation on markers of glomerular filtration and kidney injury in adults with adult-onset diabetes and greater than or equal to trace amounts of proteinuria. Each period lasted 6 weeks and was separated by a 2-week washout. The main outcome was urine albumin excretion and, secondarily, markers of kidney injury (kidney injury molecule-1, N-acetyl β-d-glucosaminidase [NAG], neutrophil gelatinase-associated lipocalin [NGAL], and liver fatty acid–binding protein [LFABP]), serum markers of kidney function (cystatin C, β₂-microglobulin, and creatinine), and estimated glomerular filtration rate (eGFR).

RESULTS

Of the 31 participants, 29 finished both periods. A total of 55% were male, and 61% were African American; mean age was 67 years. At baseline, mean BMI was 31.6 kg/m², median eGFR was 76.9 mL/min/1.73 m², and median 24-h urine albumin excretion was 161 mg/day. Compared with placebo, n-3 PUFA had nonsignificant effects on urine albumin excretion (−7.2%; 95% CI −20.6 to 8.5; P = 0.35) and significant effects on urine NGAL excretion (−16% [−29.1 to −0.5%]; P = 0.04). There was no effect on serum markers of kidney function or eGFR. In subgroup analyses, there were significant decreases in 24-h urinary excretion of albumin, NGAL, LFABP, and NAG among participants taking medications that block the renin-angiotensin-aldosterone system (RAAS).

CONCLUSIONS

These results suggest a potential effect of n-3 PUFA supplementation on markers of kidney injury in patients with diabetes and early evidence of kidney disease. In the context of prior studies, these results provide a strong rationale for long-term trials of n-3 PUFA on chronic kidney disease progression.Diabetes is a leading cause of chronic kidney disease (CKD) (1). Treatments to slow the progression of CKD in diabetes include blocking the renin-angiotensin-aldosterone system (RAAS), implementing lower blood pressure (BP) treatment goals, and treating hyperglycemia (2). These therapies can also reduce urine protein excretion, a marker of disease severity. Indeed, maximal reduction of urine protein excretion has been proposed as a goal of drug therapy (3). Long-chain n-3 polyunsaturated fatty acid (n-3 PUFA) supplements may improve endothelial function, lower BP, and have independent antiproteinuric effects (4). However, evidence of benefit from supplementation with n-3 PUFA on urine protein excretion in the setting of diabetic kidney disease is inconsistent (5–11).New markers of kidney function and injury hold considerable promise as a means to evaluate the potential benefits of therapies designed to retard the progression of CKD. Biomarkers of tubulointerstitial kidney damage, including kidney injury molecule-1 (KIM-1), N-acetyl β-d-glucosaminidase (NAG), neutrophil gelatinase-associated lipocalin (NGAL), and liver fatty acid–binding protein (LFABP) may have greater sensitivity for identifying effects on kidney injury than total urine protein or albumin excretion, which reflect both kidney injury and hemodynamic effects (12,13). Novel serum markers, including β₂-microglobulin and cystatin C, may provide greater sensitivity for determining short-term effects of therapies on estimated glomerular filtration rate (eGFR) than traditional markers of filtration. These new markers of kidney function and injury might be especially useful in guiding the design of subsequent long-term trials.In this context, we conducted a randomized, controlled crossover trial to evaluate the efficacy of n-3 PUFA supplements on improving markers of kidney injury and function in adults with adult-onset diabetes and greater than or equal to trace amounts of proteinuria.     

Plasma and urine betaine and dimethylglycine variation in healthy young male subjects

ObjectivesWe aimed to compare the individuality (within subject consistency) of plasma and urine betaine and N,N-dimethylglycine.Design and methodsIn two separate groups of 8 males (ages 19 to 40), plasma (10) and urine (6) samples were collected either over a single day or over an 8 week period. The individuality of the betaine and N,N-dimethylglycine plasma concentrations and excretions were estimated by one-way repeated measures analysis of variance. The reliability coefficients and indices of individuality were calculated. The between-subject variation in the study population was compared with that in a normal population (n = 192 for plasma, 205 for urine).ResultsPlasma betaine concentrations were significantly different between subjects over 24 h and 8 weeks (p < 0.00001). Plasma dimethylglycine concentrations were different over 24 h. Urine betaine and dimethylglycine excretions were different in both (p < 0.0001). Betaine was more individual than dimethylglycine in both plasma and urine. Compared with a normal healthy population, the between-subject variation in plasma betaine was less (p < 0.001) in the study group, but similar for dimethylglycine and for urine betaine.ConclusionsPlasma betaine and urinary betaine excretions are more individual than dimethylglycine. Plasma and urine betaine are highly individual in the general population.     

Targeting a Braf/Mapk pathway rescues podocyte lipid peroxidation in CoQ-deficiency kidney disease

Mutations affecting mitochondrial coenzyme Q (CoQ) biosynthesis lead to kidney failure due to selective loss of podocytes, essential cells of the kidney filter. Curiously, neighboring tubular epithelial cells are spared early in disease despite higher mitochondrial content. We sought to illuminate noncanonical, cell-specific roles for CoQ, independently of the electron transport chain (ETC). Here, we demonstrate that CoQ depletion caused by Pdss2 enzyme deficiency in podocytes results in perturbations in polyunsaturated fatty acid (PUFA) metabolism and the Braf/Mapk pathway rather than ETC dysfunction. Single-nucleus RNA-Seq from kidneys of Pdss2^kd/kd mice with nephrotic syndrome and global CoQ deficiency identified a podocyte-specific perturbation of the Braf/Mapk pathway. Treatment with GDC-0879, a Braf/Mapk-targeting compound, ameliorated kidney disease in Pdss2^kd/kd mice. Mechanistic studies in Pdss2-depleted podocytes revealed a previously unknown perturbation in PUFA metabolism that was confirmed in vivo. Gpx4, an enzyme that protects against PUFA-mediated lipid peroxidation, was elevated in disease and restored after GDC-0879 treatment. We demonstrate broader human disease relevance by uncovering patterns of GPX4 and Braf/Mapk pathway gene expression in tissue from patients with kidney diseases. Our studies reveal ETC-independent roles for CoQ in podocytes and point to Braf/Mapk as a candidate pathway for the treatment of kidney diseases.     

Beta-Lactamases Produced by a Pseudomonas aeruginosa Strain Highly Resistant to Carbenicillin

A Pseudomonas aeruginosa strain isolated at Besançon Hospital, France, proved to be highly resistant to carbenicillin and showed a high hydrolytic activity toward this antibiotic. We clearly demonstrated that two β-lactamases were synthetized: one of them, constitutive, has its enzymatic activity directed mainly toward penicillins, and carbenicillin appears to be its best substrate (higher V_max); thus, this β-lactamase is a “carbenicillinase” that differs from the well-known “TEM-like” enzymes. The isoelectric point of this carbenicillinase is 5.30 ± 0.03. The other one is an inducible cephalosporinase, very similar to the cephalosporinases usually found in these organisms. Its isoelectric point is 8.66 ± 0.04. These two enzymes have been separated by affinity chromatography and isoelectric focusing. The kinetic constants were measured by computerized microacidimetry.     

肾移植术后肺部感染对移植肾功能影响的初步观察

目的探讨肾移植术后患者肺部感染对移植肾功能的影响及可能原因。方法对肾移植术后出现肺部感染的89例患者,根据美国胸科协会(ATS)标准,分为重度肺部感染组37例和轻度肺部感染组52例;选取50例未发生感染的肾移植术后患者作为对照组。对重度肺部感染患者采取降阶梯治疗方案,轻度肺部感染患者则不采取此方案。观察两组感染患者治疗时免疫抑制剂的调整情况,治疗前和临床痊愈后1周、6个月、1年、3年时,患者的尿微量白蛋白/肌酐比值(ACR)、血清肌酐(Scr)以及尿β2-微球蛋白水平。并观察对照组患者的各项指标。结果重度感染组中大部分患者均减少或停用免疫抑制剂、应用静脉注射免疫球蛋白及白蛋白,轻度感染组中仅有部分患者采取这些措施。治疗前两组患者的各项指标差异无统计学意义。临床痊愈1周后,重度感染组患者ACR高于轻度感染组(P<0.05);两组间Scr差异无统计学意义(P>0.05)。痊愈后6个月、1年、3年重度感染组ACR及Scr均高于轻度感染组,差异有统计学意义(P<0.05);轻度感染组ACR及Scr均高于对照组,但差异无统计学意义(P>0.05)。重度感染组在感染时和痊愈后1周的尿β2-微球蛋白与轻度感染组比较,差异无统计学意义(P>0.05);痊愈后6个月、1年、3年重度感染组高于轻度感染组,差异有统计学意义(P<0.05);轻度感染组与对照组尿β2-微球蛋白比较,差异无统计学意义(P>0.05)。结论肾移植术后重度肺部感染可通过多种因素影响患者的肾功能。在治疗感染的同时,应采取措施以减少尿蛋白、保护肾功能。     

Arylsulfatase A activities in urine and tissues taken from bladder cancer patients

Urinary arylsulfatase A activity expressed as units/mg of urinary creatinine was significantly increased in bladder cancer patients, but not in patients with other genitourinary tract disorders, such as cystitis, urethritis and prostatic cancer, nor in patients with non-urological malignant diseases. The urinary enzyme activity was positively correlated with the stage of the bladder cancer, while post surgical follow-up revealed a marked decrease of the activity. Arylsulfatase A activity was also shown to be higher in malignant than in normal bladder tissue, demonstrating the activity to be a function of the grade of the tumor. Furthermore, the isoelectric point (pI 5.2-5.3) of the tissue enzyme in the bladder tumor coincided with that of the urine enzyme from the same cancer patients; the pI of the enzyme in urine from normal subjects was 4.7. These results suggest that most of the urinary arylsulfatase A in bladder cancer originates from tumor tissue.     

Urinary Recovery of N-Formimidoyl Thienamycin (MK0787) as Affected by Coadministration of N-Formimidoyl Thienamycin Dehydropeptidase Inhibitors

N-Formimidoyl thienamycin (MK0787) undergoes renal metabolism by a dipeptidase, dehydropeptidase I, located on the brush border of the proximal tubular cells. The effects of two inhibitors (MK-789 and MK-791) of dehydropeptidase I on the pharmacokinetics of N-formimidoyl thienamycin were studied in 41 healthy subjects receiving various combinations of N-formimidoyl thienamycin and MK-789 or MK-791. Both inhibitors affected the plasma kinetics of N-formimidoyl thienamycin only to a small extent. Plasma concentrations and the area under the plasma concentration curve increased about 20% with a proportional decrease in plasma clearance. Plasma half-life was not altered significantly. Coadministration of MK-789 or MK-791 resulted in uniform and marked increases in urinary recovery and renal clearance of N-formimidoyl thienamycin. Thus, at an N-formimidoyl thienamycin/MK-791 ratio of 1:0.25 or higher, the urinary recovery was about 72% in all subjects, whereas it varied between 7.7 and 43% when N-formimidoyl thienamycin was given alone. The ratio of the N-formimidoyl thienamycin and MK-791 doses affected response. At relatively higher doses of MK-791, significant increases of N-formimidoyl thienamycin urinary recovery, renal clearance, and urine concentrations occurred during the later part of the 10-h observation period after each administration. At a 1:1 ratio of the two drugs, the inhibition of renal metabolism of N-formimidoyl thienamycin was maintained for at least 8 h, whereas renal clearance declined as soon as 4 h after the administration of a 1:0.25 ratio. The results indicated that MK-789 and MK-791 alter the renal excretion of N-formimidoyl thienamycin from glomerular filtration plus tubular secretion to glomerular filtration only, possibly by competitively inhibiting the penetration of N-formimidoyl thienamycin into the proximal tubular cells.     

Acid hydrolases in amniotic fluid and chorionic villi at various stages of pregnancy

A study was made at various stages of pregnancy of five acid hydrolases which occur in amniotic fluid and chorionic villi and which are relevant to serious storage disorders.In amniotic fluid β-galactosidase and α-mannosidase decreased moderately towards term, while β-glucosidase decreased markedly. N-Acetyl-β-glucosaminidase and β-glucuronidase were relatively unchanged.In chorionic villi N-acetyl-β-glucosaminidase, β-galactosidase, and α-mannosidase were substantially decreased towards term, while β-glucosidase was unchanged and β-glucuronidase markedly increased.In both amniotic fluid and chorionic villi the enzyme pattern was approximately the same as that found in liver in a previous study.The findings suggest that these enzyme assays might be useful in the diagnosis of inborn errors prenatally by using amniotic fluid, and early postnatally by using chorionic villi.     

Characterization of a Novel AmpC β-Lactamase Produced by a Carbapenem-Resistant Cedecea davisae Clinical Isolate

A Cedecea davisae isolate, which was intermediate or resistant to third-generation cephalosporins and carbapenems, was recovered from a urine sample. Susceptibility testing, isoelectric focusing, and analysis of outer membrane proteins showed that AmpC β-lactamase expression combined with porin deficiency accounted for the carbapenem resistance. A cloning experiment followed by phenotypic and enzymatic characterization identified a novel class C enzyme that was phylogenetically and biochemically close to the chromosome-borne β-lactamases of the genera Enterobacter and Citrobacter.