Variable metabolism of pinacidil: lack of correlation with the debrisoquine and trimethylamine C- and N-oxidative polymorphisms

1. The urinary excretion of pinacidil and its N-oxide in man was found to vary over a five-fold range. 2. Studies in individuals with inherited deficiencies for C-hydroxylation (debrisoquine type) and trimethylamine N-oxidation showed that the N-oxidation of pinacidil did not co-segregate with these oxidative polymorphisms. 3. It is concluded that the variable N-oxidation of pinacidil is most likely to be due to variations in the activity of the P-450 isozymes rather than in the microsomal flavoprotein containing mixed-function amine oxidase of Ziegler which is considered to be responsible for the N-oxidation of trimethylamine.

Foveal regions of bird retinas correlate with the aster of the inner nuclear layer

A radiate specialization, the aster, has been found in whole-mount retinas of birds and is associated to each one of the temporal and nasal fovea, with the one related to the convexiclivate nasal fovea more evident. This radial arrangement extends uniformly in all directions from the foveal pit. Transverse sections of the retina show that this structure is formed by bands of cells and bundles of fibers from the inner nuclear layer.

Blood pressure during induction and termination of the dorsal immobility response

Evidence has indicated that afferent baroreceptor input may play a role in the induction of the dorsal and tonic immobility responses, which are behaviorally similar, but involve opposite posture changes upon induction (i.e., upright versus inverted, respectively). Information is lacking on the topography of the blood pressure response during periods of dorsal immobility. The blood pressure response of the adult Wistar rat during induction and termination of dorsal immobility was compared to the blood pressure response during a condition which controlled for posture change. Each animal received two control trials, ten dorsal immobility trials and then two control trials in two successive sessions four and ten days after surgery. A precise second-by-second topographical analysis of the dorsal immobility response revealed a sharp rise in blood pressure at trial onset of 18.4 mmHg, followed by a return below pretrial levels and then subsequent recovery back to pretrial levels by the tenth-trial second. This level was maintained until the last five seconds of immobility when a rapid blood pressure elevation occurred. This terminating elevation correlated highly with the observation of large movement and probably reflected motor activity that eventually culminated in escape from immobility. The vertical posture change of the control condition, on the other hand, resulted in a gradual diminution of blood pressure, which implied that the initial blood pressure elevation during initiation of the dorsal immobility response could not be accounted for simply by posture change.(ABSTRACT TRUNCATED AT 250 WORDS)

Shoulder kinesthesia after anterior glenohumeral joint dislocation

The purpose of this study was to examine kinesthesia in normal (uninjured) shoulders and in shoulders with a history of glenohumeral joint dislocations. Both shoulders of 10 healthy subjects and 8 subjects with a history of unilateral anterior dislocation were tested for accuracy of angular reproduction, threshold to sensation of movement, and end-range reproduction using a motor-driven shoulder-wheel apparatus. An analysis of variance revealed significant differences (p less than .001) between the injured and uninjured shoulders for all three tests. Post hoc analysis showed significant differences (p less than .02) between the involved shoulders and all uninvolved shoulders. No significant difference was found among the uninvolved shoulders. The results of this study indicate that kinesthetic deficits occur after glenohumeral dislocation and may result in abnormal neuromuscular coordination and subsequent reinjury of the shoulder. Clinicians should consider rehabilitation of shoulder kinesthesia using therapeutic activation of the shoulder joint and muscle receptors when treating patients with previous dislocations.

Growth hormone stimulates insulin-like growth factor I actions on adult articular chondrocytes

We report effects of adding insulin-like growth factor I (IGF-I) and methionyl human growth hormone (GH), alone or in combination, to adult bovine articular chondrocytes plated at high density. Purified human and synthetic IGF-I stimulated chondrocyte DNA and proteoglycan synthesis. GH had no effect on either process. However, GH added in combination with IGF-I increased proteoglycan, cell-associated proteoglycan, and keratan sulfate synthesis over levels observed with IGF-I alone. IGF-I and GH did not alter the hydrodynamic size of proteoglycans or synthesis of collagen. Our results show that GH and IGF-I act together to stimulate adult chondrocyte extracellular matrix synthesis.

Trimethylaminuria: the detection of carriers using a trimethylamine load test

A method potentially of value for investigating putative heterozygotes or carriers of trimethylaminuria by using a single oral dose of trimethylamine (TMA) is described. For healthy volunteers under normal dietary condition and following oral challenge with 300 mg and 600 mg TMA-base, over 90% of the urinary TMA was excreted in the form of TMA (93.6 +/- 1.6%). However, at a dose level of 900 mg TMA-base, there was clear evidence of saturation of the N-oxidation reaction as urinary TMA excretion declined to 77.2% (range 74.8-78.9) of the total dose of TMA. By contrast, in pedigree studies based upon propositi with trimethylaminuria, several parents were identified who showed clear evidence of saturation of the N-oxidation of TMA at the 600 mg TMA-base dose level, but not at 300 mg TMA-base or under normal dietary condition. In these individuals, the proportion of urinary TMA as trimethylamine N-oxide (TMAO) declined to (77.3 +/- 1.7%). Accordingly we propose that the oral administration of 600 mg TMA-base and the analysis of the following 0-8-h urine collection may be useful for the investigation of possible carriers of trimethylaminuria.

Induction of articular cartilage degradation by recombinant interleukin 1 alpha and 1 beta

The purpose of this study was to compare the effects of human recombinant interleukin 1, alpha and beta, on articular cartilage. The effects of rIL-1 alpha and rIL-1 beta on proteoglycan degradation and synthesis following treatment of bovine articular cartilage in serum-free organ culture were quantified. Purified human IL-1 and both rIL-1 alpha and rIL-1 beta induced a two-fold or greater increase in glycosaminoglycan (GAG) release from cultured articular cartilage. Levels or rIL-1 alpha as low as 15 pM induced increased proteoglycan degradation whereas identical levels of rIL-1 beta did not. Killing of the cartilage cells abolished induced GAG release by all forms of IL-1. Analysis of proteoglycan size following IL-1 treatment showed limited degradation of material released into the culture medium or remaining within cartilage. Both forms of recombinant IL-1 inhibited GAG synthesis when continually present in the culture medium. Actinomycin D and cycloheximide inhibited IL-1 dependent cartilage destruction whereas indomethacin did not.

Molecular analysis of organelle DNA of different subspecies of rice and the genomic stability of mtDNA in tissue cultured cells of rice

Chloroplast (ct) and mitochondrial (mt) DNAs were isolated from two subspecies of rice (Oryza sativa), japonica (Calrose 76) and indica (PI353705) and compared by restriction endonuclease fragment pattern analysis. Similarly, PI353705 (A5) mtDNA was also compared with the mtDNA of its long term tissue cultured line, BL2. Variation in the ctDNA of the 2 subspecies was detected with two (AvaI and BglI) of the 11 restriction endonucleases tested, whereas their mtDNAs showed considerable variation when restricted by PstI, BamHI, HindIII and XhoI endonucleases. Thus, the chloroplast DNA was more highly conserved than the mtDNA in the subspecies comparisons. Only minor variation was observed between the restriction endonuclease patterns of the mtDNAs of BL2 and A5. Southern blots of mtDNA were hybridized with heterologous probes from maize and spinach organelle genes. Differences were found in the hybridization patterns of the two subspecies for six of the eight (mitochondrial and chloroplast) probes tested. Two of the seven (mitochondrial) probes (coxII and 26S rRNA) detected tissue culture generated variation in mtDNA. The relative values of restriction endonuclease and hybridization patterns for studying phylogenetic and genetic relationships in rice are discussed.

Hospital pharmacy employment considerations for the chemically dependent health-care professional

Experiences and decisions of a pharmacy services management team involving two chemically dependent individuals, one an existing pharmacist employee and the other a pharmacist applicant, are described. Because our standing on chemical dependency was to rehabilitate rather than terminate, we chose to develop a systematic approach to dealing with this problem in our employees. In the case of the existing pharmacist employee, we decided to initiate rehabilitation by intervention, a process that involved direct confrontation of the individual by his spouse and mother, immediate supervisor, a certified alcohol and drug abuse counselor, and a representative from the hospital's employee assistance program. The employee was treated by psychological/behavioral therapy on an inpatient basis. After discharge, the employee returned to work under specific terms outlined in a return-to-work contract covering the first 24 months; support structures at the workplace to guard against relapse were also instituted. Factors that might precipitate relapse were identified, and a policy for dealing with relapsing employees was developed. The pharmacist applicant was assessed like any other applicant, but a few other factors relevant to her recovering status, such as the length of continuous abstinence she had attained, were considered. An employment contract resembling the return-to-work contract also was developed. Experience with the chemically dependent employee led to the creation of a model for dealing effectively and fairly with employees afflicted with the disease of chemical dependency. We continue to support our institutional decision to rehabilitate and not terminate such employees.

Acylation of gelatin-agarose and the enhancement by heparin of fibronectin binding

The enhancement of the binding of plasma fibronectin to collagen or gelatin by heparin was previously thought to be due primarily to interaction of heparin with fibronectin. We observed, however, that the elution of purified human plasma fibronectin from heparin-treated gelatin-agarose required the same high urea concentrations regardless of whether heparin treatment preceded or followed fibronectin adsorption. Acylation of gelatin-agarose with acetic anhydride or succinic anhydride had little effect upon fibronectin binding, yet the heparin enhancement of fibronectin binding was abolished by either acylation reaction. When heparin binding to gelatin-agarose was investigated with dansyl heparin, gelatin-agarose bound substantial quantities of labeled heparin which could be readily dissociated from the matrix with 2 M NaCl. Acetylated gelatin-agarose did not bind detectable amounts of dansyl heparin. We interpret these results as evidence that the stronger binding of fibronectin to gelatin-agarose in the presence of heparin is due to heparin itself binding to gelatin, thus allowing fibronectin to bind simultaneously to both immobilized ligands through appropriate domains of the glycoprotein.

Poor sulphoxidation ability in patients with food sensitivity

Patients with well defined reactions to foods were examined for their ability to carry out both sulphur and carbon oxidation reactions by using carbocisteine and debrisoquine as probe compounds. The proportion of poor sulphoxidisers (58 of 74) was significantly greater than that of a previously determined normal control population (67 of 200; p less than 0.005). The proportion of poor carbon oxidisers was not significantly different from the controls. Metabolic defects may play a part in the pathogenesis of adverse reactions to foods.

Mitochondrial DNA variation in pearl millet and related species

Mitochondrial DNA (mtDNA) restriction endonuclease fragment patterns and patterns of mtDNA hybridized by mitochondrial gene probes were used to study phylogenetic relationships of seven Pennisetum species, including five P. americanum (pearl millet) ecotypes and a reference species from the distantly related genus, Panicum. The restriction patterns of the pearl millet ecotypes were uniform with the exception of the ecotype collected in Ethiopia. The probe hybridization method revealed more variability, with both the Rhodesian and Ethiopian ecotypes differing from the others and from each other. Considerable restriction pattern polymorphism was noted among different species of Pennisetum, and Panicum. Significant relationships were noted of Pennisetum polystachyon to P. pedicellatum and of P. purpureum to P. squamulatum using the restriction pattern method. In addition to those relationships, the hybridization method showed relationships of pearl millet to P. purpureum and to P. squamulatum. The relationships noted between species by the hybridization method agreed more closely to the cytological data than those indicated by the restriction pattern method. Therefore, the hybridization method appeared to be the preferred method for studying species relationships. The mitochondrial genome size of pearl millet was calculated to be 407 kb and the mitochondrial genome sizes of other Pennisetum species ranged from 341 to 486 kb.

A diffusion model of the transient response of the cochlear inner hair cell synapse

One class of models of hair cell synaptic function that has been investigated in recent years consists of one or more reservoirs of synaptic material connected to other reservoirs and/or the synaptic cleft by means of diffusion paths. One such general model is considered here, comprising two reservoirs and a global source of synaptic material connected in series and releasing material into the synaptic cleft by a diffusion path characterized by an intensity-dependent permeability. The explicit form of the solution of the model for a sudden onset of stimulation is derived: The solution comprises two exponentially decaying terms plus a constant. This solution is shown to have a unique inverse. This allows the determination of the parameters of the model directly from experimental data from auditory-nerve fibers in the Mongolian gerbil. The behavior of the derived model parameters with variation of stimulus intensity is demonstrated, and implications for synaptic function are discussed.

Bronchogenic cyst causing a unilateral ventilation-perfusion defect on lung scan

A 37-year-old woman had pleuritic chest pain, dyspnea, and normal findings on chest roentgenogram. Lung scan showed markedly diminished perfusion to the right lung with a matched ventilatory defect. Further evaluation revealed a bronchogenic cyst. After resection, the lung scan was normal. To our knowledge, this is the first report of a bronchogenic cyst causing a reversible, unilateral ventilation-perfusion defect on lung scan.

Elevated lactate dehydrogenase values in patients with Pneumocystis carinii pneumonia

We investigated the source of elevated serum lactate dehydrogenase (LDH) levels in seven patients with Pneumocystis carinii pneumonia (PCP) by analyzing blood and bronchoalveolar lavage (BAL) albumin (ALB) and LDH, with isoenzyme fractionation. Four patients with non-PCP lung disease served as control subjects. In PCP patients, BAL LDH was sixfold higher, and BAL ALB, fourfold higher than in the non-PCP patients. The increased LDH/ALB in BAL as compared to serum, in addition to a BAL isoenzyme pattern characteristic of lung, suggest that BAL LDH arises from a pulmonary source. We postulate that the high correlation observed between BAL and serum LDH (r = 0.93, p less than 0.001) reflects backflow of pulmonary-derived LDH into the blood through an alveolocapillary membrane (ACM) compromised by PCP. Furthermore, a comparison of BAL LDH/ALB for each isoenzyme with the same serum ratio showed less backflow for the cationic isoenzymes. The ACM appears to sieve proteins on an electrical basis which may account for the LDH isomorphic pattern observed in the serum of PCP patients.

Denitrification in a Sand and Gravel Aquifer

Denitrification was assayed by the acetylene blockage technique in slurried core material obtained from a freshwater sand and gravel aquifer. The aquifer, which has been contaminated with treated sewage for more than 50 years, had a contaminant plume greater than 3.5-km long. Near the contaminant source, groundwater nitrate concentrations were greater than 1 mM, whereas 0.25 km downgradient the central portion of the contaminant plume was anoxic and contained no detectable nitrate. Samples were obtained along the longitudinal axis of the plume (0 to 0.25 km) at several depths from four sites. Denitrification was evident at in situ nitrate concentrations at all sites tested; rates ranged from 2.3 to 260 pmol of N 2 O produced (g of wet sediment) −1 h −1 . Rates were highest nearest the contaminant source and decreased with increasing distance downgradient. Denitrification was the predominant nitrate-reducing activity; no evidence was found for nitrate reduction to ammonium at any site. Denitrifying activity was carbon limited and not nitrate limited, except when the ambient nitrate level was less than the detection limit, in which case, even when amended with high concentrations of glucose and nitrate, the capacity to denitrify on a short-term basis was lacking. These results demonstrate that denitrification can occur in groundwater systems and, thereby, serve as a mechanism for nitrate removal from groundwater.

Histoplasmosis in patients at risk for the acquired immunodeficiency syndrome in a nonendemic setting

We reviewed 18 cases of histoplasmosis in patients at risk for the acquired immunodeficiency syndrome seen at two New York City hospitals in the past 3 1/2 years. Seventeen patients were Hispanic, including 13 born in Puerto Rico and three in South America. Clinical presentation was subacute, with high fever, weight loss, and mild respiratory symptoms with well-maintained gas exchange. Five patients had normal chest roentgenograms. The most common chest roentgenographic abnormality was diffuse small nodules. A rapid diagnosis was established histologically in 72 percent of patients, most commonly by transbronchial lung biopsy; cultures were positive in 94 percent of patients while serology was positive in five of six patients. Mycobacterium tuberculosis was a concurrent, often unrecognized, pathogen in six cases. Most patients responded to amphotericin therapy. Histoplasmosis may represent an early sign of altered host immunity in the acquired immunodeficiency syndrome.

The role of intestinal microflora in the formation of the methylthio adduct metabolites of paracetamol. Studies in neomycin-pretreated and germ-free mice

The contribution of the gastrointestinal microflora to the formation of methylthio adducts from paracetamol has been studied by comparing the fate of this drug in conventional mice with that in germ-free and neomycin-treated animals. In both germ-free and neomycin-treated mice there was a highly significant reduction in the urinary excretion of 3-methylthioparacetamol, its glucuronic acid and sulfate conjugates and its sulfoxide, with no other systemic alteration to the overall fate of the drug. These data are consistent with the gut flora playing a major role in the C-S cleavage of paracetamol-3-cysteine, thereby reducing the excretion of the array of methylthio adducts subsequently formed by tissue enzymes from 3-thioparacetamol, the putative product of the C-S cleavage.

Trimethylaminuria ('fish-odour syndrome'): a study of an affected family

1. Beginning with a single propositus, who had been previously diagnosed at the age of 10 as suffering from trimethylaminuria (fish-odour syndrome), both her parents and two sisters were investigated biochemically with respect to their ability to N-oxidize trimethylamine (TMA), both when derived from the diet and when administered exogenously. 2. Both the propositus and a second sister were markedly deficient in their ability to N-oxidize TMA, both when derived from the diet and when given as such; furthermore, both siblings readily developed the symptoms of fish-odour syndrome as characterized by a strong objectionable breath and body odour shortly after the oral administration of TMA (300 mg). 3. At this dose level of TMA, neither of the parents nor the third sister showed any evidence of impaired N-oxidation ability nor did they experience any 'fish-odour' symptoms. 4. With an oral challenge of 600 mg of TMA, both the parents showed a clear impairment of N-oxidation capacity which was not seen in six healthy unrelated volunteers. Both parents experienced a fish-odour syndrome at this level of TMA challenge. 5. The family data support the hypothesis that trimethylaminuria is an inborn error in the ability to N-oxidize TMA which is inherited as an autosomal recessive trait. Furthermore, experience with this family suggests that an oral challenge dose with 600 mg of TMA may be used to identify carriers of the condition.

Insulin resistance in denervated skeletal muscle. Inability of insulin to stimulate dephosphorylation of glycogen synthase in denervated rat epitrochlearis muscles

We have investigated the effects of insulin and motor denervation on the phosphorylation of glycogen synthase in skeletal muscle. Rat epitrochlearis muscles were denervated in vivo 3 days before the contralateral and denervated muscles were incubated in vitro with 32Pi to label sites in glycogen synthase. The 32P-labeled synthase was rapidly immunoprecipitated from extracts under conditions which prevented changes in the phosphorylation state of the enzyme. When 32P-labeled synthase from contralateral muscles was cleaved with CNBr, essentially all of the 32P was recovered in two fragments, denoted CB-1 and CB-2. Incubating these muscles with insulin decreased the 32P content of each fragment by approximately 25%, indicating that the hormone stimulated dephosphorylation of at least two sites. Peptide mapping by reverse phase high performance liquid chromatography was performed to resolve phosphorylation sites more completely. The results suggest that the enzyme was phosphorylated in sites 1a, 1b, 2, 3(a+b+c), and 5. Insulin stimulated dephosphorylation of sites in peptides presumed to contain sites 1b, 2, and 3(a+b+c). Synthase from denervated muscles appeared to contain the same amount of phosphate as enzyme from contralateral muscles, and denervation did not detectably affect the distribution of 32P within the subunit. However, denervation abolished the effect of insulin on decreasing the 32P content of synthase. The results indicate that the insulin resistance induced by denervation involves a loss in the ability of insulin to stimulate dephosphorylation of glycogen synthase.

Time-varying magnetic fields: effects of orientation on chondrocyte proliferation

The purpose of this study was to determine the effect of orientation of pulsed electromagnetic fields (PEMFs) on cellular proliferation and extracellular matrix synthesis. Bovine articular chondrocytes were cultured in PEMFs (repetitive pulse at 72 Hz) generated using Helmholtz coils oriented either parallel (horizontal) or perpendicular (vertical) to the plane of cell adhesion. Dissipation of signal energy in the form of heat increased the temperature of the PEMF coils by 2 degrees C and the tissue culture medium by 1 degree C. Therefore, control coils, which emitted no PEMFs, were heated to the temperature of PEMF coils by circulating water. Chondrocytes were cultured in 16-mm-well culture plates, and the data for individual wells were pooled as triplicates. Although not observed by microscopic examination of individual wells, positionally dependent electric field effects may be minimized by this approach. PEMFs generated by coils oriented vertically significantly decreased chondrocyte proliferation. The effect was dependent on the concentration of serum in the culture media. At 3% serum concentration, the total cell number attained after 10 days of culture was reduced by 50% in stimulated cultures when compared with controls. At 5% serum concentration, there was no effect. PEMFs applied by coils oriented horizontally did not alter proliferation of articular chondrocytes. PEMFs had no effect on synthesis of extracellular matrix by chondrocytes plated at high density, irrespective of orientation.

Time dependent pentylenetetrazol-like cues subsequent to diazepam administration

Seventy male Sprague-Dawley rats were trained to discriminate which of two levers to press for milk reinforcement on a VI-20 schedule of reinforcement on the basis of whether they were injected subcutaneously with 0.75 mg/kg diazepam or 10.0 mg/kg pentylenetetrazol. Following discrimination acquisition, a dose-response function was generated for each drug during 5-min extinction periods. Subjects were then assigned to one of seven groups on the basis of their per cent responding during saline testing. Each group was injected with 5 mg/kg diazepam and then given a 5-min extinction test at intervals of 2, 4, 6, 8, 12, 16, 20, or 24 h subsequent to injection. The results indicated that at the shorter time intervals the animals responded on the diazepam lever. However, as the time interval between injection and testing lengthened, responding on the PTZ bar gradually increased until by 12 h following injection with diazepam the animals were responding as though they had received an injection of 5 mg/kg PTZ. Following this period of rebound, choice behavior returned to baseline by 24 h post-injection.

Quantitation of glycocalyx production in coagulase-negative Staphylococcus

The purpose of this study was to develop sensitive and accurate methods of quantitating bacterial glycocalyx. Coagulase-negative staphylococci were cultured in trypticase soy broth. Quantitation of slime production was evaluated using various methods of fixation and staining. The amount of dye associated with bacterial slime was assessed spectrophotometrically following solubilization of the dye-biofilm complex by 0.2 M NaOH at 85 degrees C for 1 h. Carnoy's solution was optimal for fixation of the slime, and toluidine blue staining was most reproducible. Fifteen strains of Staphylococcus epidermidis showed a gradation in biofilm production ranging from high, medium, to low that was strain stable. Irrespective of the technique used, high, medium, and low producers of bacterial slime remained in the same category and always showed significantly different optical density readings (p less than 0.05). In our experiments, solubilization of a toluidine blue-bacterial biofilm complex was a direct, simple, and efficient method for reproducibily quantitating glycocalyx. This method provides a useful means of rapid quantitation of biofilm production to assess its role in the infection process and in the response to antibiotic therapy.

Biochemistry of fusion mass consolidation in the sheep spine

We report here the biochemistry of fusion mass consolidation in sheep spines during a 1-year period following autogenous cortical-cancellous bone grafting and stabilization with Harrington distraction rods. Biochemical analysis of vertebral fusion mass included determination of wet weight and dry weight and quantification of glycosaminoglycan, collagen, calcium, and phosphate following extraction with neutral EDTA and proteolytic hydrolysis with papain. Our results showed that at 1 week after surgery, the fusion mass consisted of original cortical and cancellous bone graft material. The cortical bone graft was partially resistant to EDTA-papain treatment, resulting in a residue containing hydroxyproline and mineral. At 12 weeks after surgery, the fusion mass had become a homogeneous material, which, like cancellous bone graft, was completely susceptible to treatment by EDTA-papain. Collagen content of consolidating fusion mass was highest at 16 weeks after surgery when normalized to dry weight; glycosaminoglycan content was highest within 6 weeks after surgery. Mineral content was lowest at the 6-week stage but by 12 weeks after surgery, it was comparable with original bone grafting material. At 24 and 52 weeks after surgery, fusion mass consolidation was characterized by an increase in the proportion of organic and mineral components resistant to EDTA-papain. The appearance of the EDTA-papain-resistant material in the fusion mass coincided with formation of lamellar bone and successful consolidation.