Highlights of the Digital Imaging Network-Picture Archiving and Communications System Project.

The Department of Defense issued its requirements for a Digital imaging Network-Picture Archiving and Communications System (DIN-PACS) in a Request for Proposals to industry in January, 1997. The DIN-PACS shall be an open systems network of digital devices designed for the effective acquisition, transmission, display and management of diagnostic imaging studies. This network is primarily based on two international standards, Digital imaging and Communications in Medicine (DICOM) and Health Level 7 (HL7). The DIN-PACS is required to communicate in a bidirectional manner with the Department of Defense standard hospital information system called the Composite Health Care System (CHCS) through an HL7 compliant interface. The DIN-PACS model and its published specifications stress functionality and performance rather than system architecture to allow industry to propose optimal approaches for implementation. This paper discusses the functional requirements of the DIN-PACS in terms of its internal operations as well as its communication with external systems and components. This is a US government work. There are no restrictions on its use.

Influence of gestational age, birth weight, and asphyxia on neonatal neurobehavioral performance.

The objectives of this study were to determine the influence of birth weight, gestational age, and asphyxia on neurobehavioral performance at 40 weeks conceptional age, and to demonstrate that this performance may differ in preterm high-risk infants when using low-risk preterm rather than healthy term infant norms. A cross-sectional comparative design was used to compare neurologic behavior in healthy and high-risk newborns at 40 weeks conceptional age using the Einstein Neonatal Neurobehavioral Assessment Scale. Seventy-four high-risk newborns were selected from a consecutive sample of asphyxiated, very-low-birth-weight, and small-for-gestational-age neonates. Controls did not fulfill any of the high-risk criteria and had no pre- or perinatal complications. There were 37 healthy term and 17 low-risk preterm controls. Statistically significant differences occurred between high-risk newborns and term controls for the total score (P < .001) as well as for most individual items (P < .05). Analysis of high-risk subgroups revealed that small-for-gestational-age and term asphyxiated newborns had the most abnormal responses. When comparing test performance between preterm high-risk and term controls, the majority of test items achieved significance (P < .05); however, when compared to low-risk preterm controls, fewer items were abnormal, and the probability level on abnormal items was less significant than expected. This disparity in interpretation of neurobehavioral status in preterm high-risk neonates using a preterm versus term reference sample warrants further investigation. Appropriate normative standards for preterm infants require definition because it may increase the utility of the neonatal neurologic examination and its prognostic value.

Prognostic significance of multimodality evoked response testing in high-risk newborns.

Exposure to hypoxic-ischemic events in fetal or neonatal life may lead to permanent brain damage and subsequent neurodevelopmental deficits. Clinical and diagnostic tools have been somewhat helpful in identifying an at-risk group, particularly those patients sustaining significant neurologic sequelae. In this prospective study, the prognostic significance of multimodality evoked responses in high-risk newborns was examined. A group of 44 high-risk newborns, as well as 14 healthy newborns, were tested during the newborn period with auditory brainstem responses and somatosensory evoked responses; these tests were repeated at 2 and 6 months corrected age. A neonatal neurologic examination, the Einstein Neonatal Neurobehavioral Assessment Scale, was also conducted. At 1 year corrected age, both groups were assessed in a blind fashion by a pediatric neurologist and a psychologist to determine neurodevelopmental outcome. Results indicated that somatosensory evoked response abnormalities in particular predict an abnormal neurologic status at 1 year of age. Abnormalities that persisted or worsened correlated with severe neurologic impairment, whereas an abnormal somatosensory evoked response that improved or normalized in infancy was associated with mild to moderate neurologic sequelae. Increased brainstem conduction in the auditory brainstem responses was also associated with neurologic sequelae. Normal findings from auditory brainstem responses and somatosensory evoked responses predicted normal developmental scores in all areas, as well as a normal neurologic outcome at 1 year with negative predictive powers ranging from 85-100%. Evoked response testing appears to be an important adjunct to the neurologic investigation of high-risk newborns.

Emended description of Kingella denitrificans (Snell and Lapage 1976): correction of the maltose reaction.

Snell and Lapage proposed that the bacterium designated CDC group TM-1 be named Kingella denitrificans. Their description of the organism indicated that it produced acid from maltose which was in contrast with an earlier report from our laboratory that maltose was not utilized. In an attempt to explain the different findings in the two laboratories, the type strain and two additional strains of K. denitrificans were tested for acid production from maltose in phenol red broth, the rapid fermentation test, fermentation broth with Andrade's indicator, and oxidation-fermentation base. These media were tested without additional supplements and with supplements of horse serum (5% [vol/vol]) or rabbit serum (5% [vol/vol]). The results indicated that K. denitrificans does not produce acid from maltose. It was demonstrated that maltose in media containing serum is converted to glucose from which acid can be produced by K. denitrificans. The supplementation of maltose medium with horse serum by Snell and Lapage apparently had produced a false-positive maltose reaction. The description of K. denitrificans is emended to indicate that maltose is not utilized.

Characterization of some groups of gram-negative nonfermentative bacteria by the carbon source alkalinization technique.

A total of 541 gram-negative nonfermentative bacterial strains comprising 26 species and unclassified groups were characterized by routine diagnostic and carbon substrate alkalinization techniques. These microorganisms were tested for the ability to cause alkalinization of a basal medium on a total of 217 substrates. We found that 58 carbon substrates had some discriminatory potential. We also performed 30 routine diagnostic tests. The results of these studies were evaluated by numerical taxonomy techniques. A cluster analysis of the results by the Jaccard coefficient method identified 30 clusters at the 45% level. We identified 39 tests that separated most of the groups. Groups of similar organisms or organisms that were difficult to identify were analyzed, and tests that were differential were identified. Because of variability within the clusters, further studies utilizing deoxyribonucleic acid-deoxyribonucleic acid homologies should be undertaken.

Characterization and identification of 95 diphtheroid (group JK) cultures isolated from clinical specimens.

Ninety-five cultures of group JK bacteria isolated from clinical specimens were characterized morphologically and biochemically. The microorganisms were isolated primarily from blood cultures. The bacterial cultures produced positive reactions when tested for catalase, Tween hydrolysis, and carbohydrate fermentation. Glucose and galactose were fermented by more than 90% of the organisms. Gas-liquid chromatography of trimethylsilyl derivatives of whole-cell hydrolysates of some of the group JK cultures yielded nearly identical elution profiles. The group JK microorganisms were susceptible to vancomycin but were resistant to most of the other 17 antimicrobial agents tested. A method is presented for differentiating the group JK microorganisms from other similar bacteria encountered in clinical specimens. Although these bacteria rarely occur in clinical specimens, they are capable of producing fatal infections (endocarditis and sepsis) in humans.

Carbon substrate utilization studies of some cultures of Alcaligenes denitrificans, Alcaligenes faecalis, and Alcaligenes odorans isolated from clinical specimens.

One hundred and sixty-two cultures of Alcaligenes species (A. denitrificans, A. faecalis, and A. odorans) of clinical origin were characterized by routine diagnostic and carbon substrate utilization techniques. The microorganisms were tested for their ability to utilize a total of 188 substrates. Substrate utilization was assayed by (i) growth stimulation and (ii) substrate alkalinization. The A. denitrificans and A. odorans cultures had unique substrate utilization profiles for each species. The A. faecalis isolates were redefined by colonial morphology into two biotypes: (i) biotype I, morphologically and biochemically similar to the A. denitrificans cultures and (ii) biotype II, morphologically similar to the A. odorans cultures.

Preliminary observations on the application of the multiple inocula (replicator) method for carbon substrate utilization studies of Alcaligenes faecalis.

The use of the replicator technique in evaluating carbon source utilization by 55 cultures of Alcaligenes faecalis was examined. Six of the 20 substrates tested were utilized by the bacterial cultures. In this study, the reproducibility of the technique was 100%.

Comparison of thirty-seven strains of Vd-3 bacteria with Agrobacterium radiobacter: morphological and physiological observations.

Thirty-seven cultures of Vd-3 bacteria, isolated from clinical specimens, were characterized morphologically and physiologically. The cultures produced positive reactions when tested for oxidase, urease, nitrate reduction, phenylalanine deaminase, oxidative metabolism of carbohydrate substrates, and 3-ketolactose production. These peritrichously flagellated microorganisms were isolated primarily from the respiratory tract. When compared to authentic strains of Agrobacterium, they appeared to be most similar to A. radiobacter. Gas-liquid chromatography of trimethylsilyl derivatives of whole-cell hydrolysates of some of the Vd-3 strains and A. radiobacter yielded nearly identical elution patterns. The Vd-3 cultures were identified as probable strains of A. radiobacter. A method is presented for differentiating cultures of A. radiobacter from other similar bacteria encountered in clinical specimens. Although these bacteria rarely occur in clinical specimens, the clinical microbiologist should be familiar withe their outstanding characteristics.

Recognition of Pseudomonas pickettii in the clinical laboratory: biochemical characterization of 62 strains.

Pseudomonas pickettii strains were studied to determine the characteristics essential for their identification in the clinical microbiology laboratory. Preliminary investigations indicated that these glucose-oxidizing, denitrifying, gram-negative rods were quite similar to an unclassified group of clinical isolates designated VA-2. Gas liquid chromatography of trimethylsilyl derivatives of whole cell hydrolysates of P. pickettii and VA-2 strains yielded nearly identical elution profiles. The VA-2 cultures were concluded to be probable strains of P. pickettii. A method is presented for differentiating cultures of P. pickettii from other similar bacteria encountered in clinical specimens.

Observation of nitrate reduction in some non-saccharolytic strains of Acinetobacter.

Clinical isolates of non-saccharolytic Acinetobacter species were observed to reduce nitrate.

Characterization and differentiation of 59 strains of Moraxella urethralis from clinical specimens.

The biochemical characteristics of 59 strains of Moraxella urethralis from clinical specimens, primarily from urine and the female genital tract, were studied. The characteristics included (i) the inability to acidify carbohydrate substrates, (ii) the ability to produce phenylalanine deaminase, (iii) the ability to reduce nitrite, (iv) the lack of urease activity, and (v) the ability of most strains to alkalinize citrate. A means of differentiating M. urethralis from Moraxella osloensis and Moraxella phenylpyruvica was determined.

Pseudomonas putrefaciens isolates from clinical specimens.

A total of 109 cultures of Pseudomonas putrefaciens isolated from clinical specimens were studied. The cultures were separated into two groups. The majority of the group 1 isolates, comprising 31 cultures, were characterized by (i) growth in plain nutrient broth, but no growth in broth supplemented with NaCl at concentrations of 7% and above, (ii) no growth on Salmonella-Shigella (SS) agar, and (iii) production of acid from the carbohydrates, sucrose, maltose, arabinose, and dextrin. Most group 2 isolates, comprising 78 cultures, were (i) unable to grow in plain nutrient broth, but grew well in broth supplemented with NaCl at a concentration of 7 to 10%, (ii) able to grow on SS agar, and (iii) unable to produce detectable amounts of acid from any of the carbohydrates tested except for variable results with glucose and fructose.

Amino acid- -naphthylamide hydrolysis by Pseudomonas aeruginosa arylamidase.

The intracellular and constitutive arylamidase from Pseudomonas aeruginosa was purified 528-fold by salt fractionation, ion-exchange chromatography, gel filtration, and adsorption chromatography. This enzyme hydrolyzed basic and neutral N-terminal amino acid residues from amino-beta-naphthylamides, dipeptide-beta-naphthylamides, and a variety of polypeptides. Only those substrates having an l-amino acid with an unsubstituted alpha-amino group as the N-terminal residue were susceptible to enzymatic hydrolysis. The molecular weight was estimated to be 71,000 daltons. The lowest K(m) values were associated with substrates having neutral or basic amino acid residues with large side chains with no substitution or branching on the beta carbon atom.

Separate nitrite, nitric oxide, and nitrous oxide reducing fractions from Pseudomonas perfectomarinus.

Pseudomonas perfectomarinus was found to grow anaerobically at the expense of nitrate, nitrite, or nitrous oxide but not chlorate or nitric oxide. In several repetitive experiments, anaerobic incubation in culture media containing nitrate revealed that an average of 82% of the cells in aerobically grown populations were converted to the capacity for respiration of nitrate. Although they did not form colonies under these conditions, the bacteria synthesized the denitrifying enzymes within 3 hr in the absence of oxygen or another acceptable inorganic oxidant. This was demonstrated by the ability, after anaerobic incubation, of cells and of extracts to reduce nitrite, nitric oxide, and nitrous oxide to nitrogen. From crude extracts of cells grown on nitrate, nitrite, or nitrous oxide, separate complex fractions were obtained that utilized reduced nicotinamide adenine dinucleotide as the source of electrons for the reduction of (i) nitrite to nitric oxide, (ii) nitric oxide to nitrous oxide, and (iii) nitrous oxide to nitrogen. Gas chromatographic analyses revealed that each of these fractions reduced only one of the nitrogenous oxides.

Amino acid-beta-naphthylamide uptake by Pseudomonas aeruginosa.

Studies on the arylamidase of Pseudomonas aeruginosa indicate that the enzyme is intracellular and constitutive. However, in cells grown in a basal salts medium, the uptake of amino acid-beta-naphthylamide is induced by certain amino acids. The synthesis of protein(s) related to transport in response to exposure to amino acids is postulated since chloramphenicol completely inhibits the inducing effect of amino acids. The uptake of amino acid-beta-naphthylamide is energy dependent, and the amino acid residue is incorporated into bacterial protein.