Inherited anxiety-related parent-infant dyads alter LHPA activity.

The pathogenesis of post-traumatic stress disorder (PTSD) is incompletely understood. We hypothesize that disruptions in mother-child relations may be a key contributor to development of PTSD. A normal and healthy separation-individuation process requires adaptations of self- and interactive contingency in both the mother and her child, especially in early childhood development. Anxious mothers are prone to overprotection, which may hinder the individuation process in their children. We examined long-term stress hormones and other stress markers in subjects three generations removed from the Holocaust, to assess the long-term consequences of inherited behavioral and physiological responses to prior stress and trauma. Jewish subjects who recalled overprotective parental behavior had higher hairsteroid-concentrations and dampened limbic-hypothalamic-pituitary-adrenal (LHPA) axis reactivity compared to German and Russian-German subjects with overprotective parents. We suggest that altered LHPA axis activity in maternally overprotected Jewish subjects may indicate a transmitted pathomechanism of "frustrated individuation" resulting from cross-generational anti-Semitic experiences. Thus measurements of hairsteroid-concentrations and parenting practices may have clinical value for diagnosis of PTSD. We propose that this apparent inherited adaptivity of LHPA axis activity could promote higher individual stress resistance, albeit with risk of an allostatic overload.

The occurrence and treatment of false positive reactions in enzyme-linked immunosorbent assays (ELISA) for the presence of fungal antigens in clinical samples.

Non-specific positive reactions have been revealed in enzyme-linked immunosorbent assays (ELISA) of sera for the presence of fungal antigen. These false positives were recognized by their occurrence in tests for both Candida albicans and Aspergillus fumigatus antigens and by their response to dithiothreitol, combined with their reaction with non-immune rabbit globulin. A scheme is proposed which differentiates between true and false positive reactions. Use of fractionated anti-fungal globulin in conjugates reduced the incidence of false positive results in sera from hospitalized patients and eliminated them from sera of healthy subjects. The test scheme was applied to two panels of sera containing samples from patients with (a) invasive candidosis and (b) invasive aspergillosis. The relevance of ELISA tests for the detection of fungal antigen in human serum is discussed.

A preliminary report on the pharmacokinetics of ofloxacin, desmethyl ofloxacin and ofloxacin N-oxide in patients with chronic renal failure.

The in vitro activities of ofloxacin, desmethyl ofloxacin and ofloxacin N-oxide were determined and a specific high performance liquid chromatography (HPLC) assay for these 3 compounds was devised as part of a study of the pharmacokinetics of ofloxacin and its metabolites in patients with impaired renal function. Desmethyl ofloxacin had significant antimicrobial activity but less than that of the parent drug. In 2 patients with chronic renal failure, specific HPLC assay indicated an extended half-life for ofloxacin (approximately 13 hours) and the appearance in serum of low concentrations of both metabolites after 10 hours, persisting until the last blood sample was taken (32 hours). Further studies using specific assays are needed, particularly in patients undergoing haemodialysis and after administration of multiple doses.

UK NEQAS in antibiotic assays.

How providers of external quality assessment (EQA) programmes relate to and interact with the monitors and watchdog of clinical laboratory performance in the UK is described. With regard to the quality of antibiotic assays, the changes in methodologies and in performance quality between 1971 (when the UK NEQAS for Antibiotic Assays began) and 1999 is reviewed. How improvements in performance and changes of methodology are related is discussed. The findings and conclusions of two experimental pilot EQA distributions (the teicoplanin assay and serum bactericidal test) are also discussed.

Outbreaks of hospital infection in southwest England caused by gentamicin-resistant Serratia marcescens.

Five geographically separate outbreaks of hospital acquired infection caused by gentamicin-resistant strains of Serratia marcescens occurred in the period October 1977 to January 1980 in southwest England. The patients affected were in wards for general or urological surgery, or in neurosurgical, cardiothoracic or general intensive therapy units. Asymptomatic colonization was more common than symptomatic infection, although deaths and serious infections occurred. Control of spread of the bacteria proved difficult. Most strains were resistant to many currently available antibiotics besides gentamicin; only one strain became resistant to amikacin. Representative isolates where characterized by O serotype, bacteriophage type, antibiotic sensitivity pattern, production of beta-lactamases and amino-glycoside-aminocyclitol (ACAG)-modifying enzymes, and plasmid visualization. Plasmid studies provided information that complemented conventional typing methods in determining epidemiological relationships among the outbreaks.

Half-life of intracameral gentamicin after phacoemulsification.

PURPOSE: To determine the half-life of intracameral gentamicin administered during phacoemulsification. SETTING: Southampton Eye Unit, Southampton General Hospital, England. METHODS: Thirty-one patients having scleral tunnel phacoemulsification were given intracameral gentamicin in the irrigation fluid. Samples of fluid were taken from the anterior chamber at the end of the operation and at various times postoperatively. The concentration of gentamicin in the samples was determined by fluorescence polarization immunoassay and the half-life calculated for a single compartment model using a peeling algorithm. RESULTS: The concentration of gentamicin in the anterior chamber after phacoemulsification decreased by half every 51 minutes (95% confidence interval, 42 to 66 minutes). CONCLUSION: Intracameral gentamicin was cleared from the anterior chamber after phacoemulsification at a rate that prevents the maintainance of the bactericidal levels required for reliable antibiotic prophylaxis.

Assays for therapeutic monitoring and pharmacokinetic investigations of aminoglycosides: quality aspects.

Clinical laboratory investigations used to aid antimicrobial chemotherapy of serious infection include routine sensitivity testing and, in the case of those drugs with a narrow therapeutic range, routine assays for therapeutic monitoring to assist with dosage individualization. Tests must be of a sufficiently high quality to be clinically useful. Laboratories ensure quality through standard operating procedures, internal quality control procedures, and participation in external quality assessment (EQA) programs. This article demonstrates how EQA returns to the United Kingdom National External Quality Assessment Scheme for Antibiotic Assays and the activity of the United Kingdom National Quality Assurance Advisory Panel showed marked improvement in the technical quality of assays as exemplified by gentamicin assays. The article also highlights additional quality concerns not subject to EQA.

Germination of Aspergillus fumigatus conidia in the lungs of normal and cortisone-treated mice.

Inhaled conidia of Aspergillus fumigatus germinated in the lungs of mice at a low rate but both germinated and ungerminated spores were cleared. Spores germinated at a high rate in the lungs of cortisone-treated mice.

Acquired immunity to Aspergillus fumigatus.

In mice preinfected with Aspergillus fumigatus for greater than or equal to days, administration of cortisone failed to stimulate mycelial growth. The liver and heart of mice preinfected for 14 days resisted infection after a cortisone + conidia challenge.

Chitin assay used to demonstrate renal localization and cortisone-enhanced growth of Aspergillus fumigatus mycelium in mice.

Aspergillus fumigatus mycelium in untreated mice (N-mice) and cortisone acetate-treated mice (C-mice) has been quantified by chemical assay of fungal chitin. Cortisone pretreatment rendered mice more susceptible to infection by A. fumigatus (mean lethal dose at 20 days, congruent to 10(6) for N-mice; less than 10(4) for C-mice). In both N- and C-mice there was renal localization of mycelial infection at conidial doses less than the mean lethal dose. At a conidial dose greater than the mean lethal dose, mycelial infection was found in the kidneys and brain of N-mice and in the kidneys, liver, and heart of C-mice. Chitin assay results showed that A. fumigatus mycelium grew more rapidly in C-mice. It is suggested that the resistance of N-mice to mycelial development may be an important mechanism whereby natural resistance to A. fumigatus is conferred.

Rapid germination of Aspergillus fumigatus conidia in mouse kidneys and a kidney extract.

Intravenously injected conidia of Aspergillus fumigatus germinated rapidly in the kidneys of untreated and cortisone-treated specific-pathogen-free (SPF) mice and in the livers of cortisone-treated SPF mice. Extracts of kidneys from untreated and cortisone-treated mice stimulated germination of A. fumigatus conidia in vitro. The possible roles of a germination stimulant and host defences in the kidney localisation of A. fumigatus infection are discussed.

A double-blind comparative trial of short-term orally administered enoxacin in the prevention of urinary infection after elective transurethral prostatectomy: a clinical and pharmacokinetic study.

A double-blind randomized comparative study was done to investigate the efficacy of enoxacin in the prevention of urinary infection after elective transurethral prostatectomy, as well as its ability to penetrate the prostate. A total of 40 patients received 200 mg. enoxacin and 40 received a placebo, given orally the night before the operation, 2 to 4 hours preoperatively and every 12 hours postoperatively for 36 hours. Urine samples for bacterial culture were obtained within 1 week preoperatively, at operation and at 48 hours, 5 days, and 2 and 6 weeks postoperatively. Samples of the serum and prostate were taken at operation and assayed for enoxacin levels. Of the placebo patients 15 had a urinary infection postoperatively (38 per cent) compared to 3 enoxacin patients (8 per cent) (p less than 0.01). Enoxacin penetrated well into prostatic tissue; the mean levels in tissue and serum were 3.1 +/- 1.8 mg. per kg. (standard deviation) and 1.26 +/- 0.48 mg. per l., respectively, with a mean tissue-to-serum ratio of 2.53 +/- 1.8.

The identification of the aminoglycoside-phosphorylating enzymes APH(2'') and APH(3') from the characterization of their reaction products by high performance liquid chromatography.

A method is described for the identification of the aminoglycoside-phosphorylating (APH) enzymes APH(2'') and APH(3') by the high performance liquid chromatographic (HPLC) identification of their products of reaction with kanamycin and ATP. Twelve reference strains which produce either APH(2'') or APH(3') were examined by both this method and the radioenzymatic profile method; correct enzyme identification was made with 12/12 of the strains by the HPLC method and 11/12 of the strains by the radioenzymatic profile method. Reaction products of APH(2'') or APH(3') with ATP and butirosin, geneticin, lividomycin, ribostamycin, sissomicin or tobramycin were also characterized by HPLC. Conditions for their chromatography are given.

Identification of individual aminoglycoside-inactivating enzymes in a mixture by HPLC determination of reaction products.

A method is described for the detection and identification of two aminoglycoside-acetylating (AAC(2') or AAC(3) or AAC(6')) or -phosphorylating (APH(2'') or APH(3')) enzymes when these are present in the same crude enzyme extract. Crude enzyme extracts were prepared from reference strains of bacteria producing AAC(2'), AAC(3), AAC(6'), APH(2'') or APH(3') enzymes and mixed to give the following paired enzyme combinations: AAC(2') + AAC(3), AAC(2') + AAC(6'), AAC(3) + AAC(6') and APH(2") + APH(3'). These enzyme mixtures were examined by the radioenzymatic profile method for the identification of aminoglycoside-modifying enzymes and their reaction products with butirosin, lividomycin and kanamycin (AAC) or lividomycin and kanamycin (APH) characterized by high performance liquid chromatography (HPLC). Only two of the eight enzymes present were identified by the radioenzymatic method, but all eight were correctly identified by the HPLC method.

The assay of chloramphenicol acetyltransferase activity by high performance liquid chromatography.

A high performance liquid chromatographic method is described for the assay of chloramphenicol acetyltransferase activity which detects the formation of both 3-acetoxy chloramphenicol and 1,3-diacetoxy chloramphenicol. In experiments performed at pH 6.8 only 3-acetoxy chloramphenicol was detected while in experiments performed at pH 7.8 both 3-acetoxy and 1,3-diacetoxy chloramphenicol were detected.

AAC(1): a new aminoglycoside-acetylating enzyme modifying the Cl aminogroup of apramycin.

An aminoglycoside-acetylating enzyme produced by a strain of Escherichia coli with an unusual resistance phenotype was characterized. This enzyme was found to mono-acetylate apramycin, butirosin, lividomycin and paromomycin and diacetylate ribostamycin and neomycin to give reaction products which were distinguishable by HPLC analysis from those of AAC(2'), AAC(3) and AAC(6') enzymes. The enzyme, however, was not found to acetylate amikacin, fortimicin, geneticin, gentamicin, kanamycin A, netilmicin or tobramycin. The reaction product from the action of this enzyme on apramycin was purified and identified by nuclear magnetic resonance studies as 1-N-acetyl apramycin. The second site at which ribostamycin and neomycin B were modified by this enzyme was not determined but is postulated as the 6'-amino group. It is proposed that this enzyme be named AAC(1).

Identification of aminoglycoside-acetylating enzymes by high-pressure liquid chromatographic determination of their reaction products.

A method to identify the aminoglycoside-acetyltransferase (AAC) enzymes AAC(3), AAC(2') and AAC(6') by high-pressure liquid chromatographic characterization of their products of reaction with tobramycin or sisomicin is described. Conditions are given for the chromatography of kanamycin A, netilmicin, neomycin, and apramycin, and their products of reaction, if any, with the three AAC enzymes are listed.

Assay of netilmicin in serum by substrate labelled fluoroimmunoassay.

A substrate-labelled fluoroimmunoassay (SLFIA) for gentamicin was used to assay netilmicin by substituting serum calibrators containing netilmicin. The assay proved highly reproducible and the results obtained showed a good correlation with the results of EMIT and microbiological assays.

Detection of circulating antigen of Aspergillus fumigatus in sera of mice and rabbits by enzyme-linked immunosorbent assay.

Circulating antigen of Aspergillus fumigatus was demonstrated in the sera of experimentally infected, cortisone-treated mice and rabbits by enzyme-linked immunosorbent assay (micro-ELISA), confirming earlier results where fungal antigen had been detected by counter-immunoelectrophoresis (CIE). Peaks of detection of circulating antigen by CIE and micro-ELISA in mice were not simultaneous suggesting that the nature of the predominant antigens may have altered during the course of infection. CIE failed to detect fungal antigen in infected rabbits whereas micro-ELISA monitored antigenemia until death. Both CIE and micro-ELISA demonstrated the rapid clearance of intravenously inoculated Aspergillus-antigen from the rabbit circulation.