Assessment of retrograde cardioplegia distribution using contrast echocardiography

Retrograde cardioplegia has gained popularity in coronary and noncoronary cardiac operations. We have used contrast echocardiography in the open-chest canine model to compare the distribution of cardioplegia delivered antegrade in the aortic root versus retrograde through the coronary sinus, and to determine the effect of coronary occlusion on that delivery. With no coronary occlusion, antegrade cardioplegia was distributed to the entire left ventricle and septum whereas retrograde cardioplegia was distributed to the left ventricular free wall but had inconsistent delivery to the septum. Acute occlusion of the left circumflex coronary artery resulted in 57.06% +/- 9.52% of the left ventricle not being perfused by antegrade cardioplegia and occlusion of both the left circumflex and anterior descending coronary arteries caused a 65.46% +/- 18.5% reduction in perfusion by antegrade cardioplegia. Acute coronary occlusion had no effect on retrograde cardioplegia distribution. We conclude that retrograde cardioplegia is less homogeneous than antegrade cardioplegia in the intact coronary circulation but that retrograde cardioplegia preserves cardioplegia distal to acutely occluded coronary arteries. Furthermore, contrast echocardiography is a useful method of assessing myocardial perfusion and may have useful clinical applications.

Assessment of myocardial perfusion during CABG surgery with two-dimensional transesophageal contrast echocardiography

No reliable, quantifiable index of tissue perfusion is currently available to assess the efforts of coronary artery bypass graft (CABG) surgery. We used two-dimensional transesophageal contrast echocardiography with sonicated Renografin-76 microbubbles to determine the distribution of myocardial blood flow during coronary artery bypass graft surgery in 15 patients. Sonicated Renografin-76 contrast agent was injected into the aortic root of all patients after institution of cardiopulmonary bypass and application of the aortic occlusive clamp. Eight patients had contrast agent injected directly into the free proximal end of the vein-CABG anastomosis. All patients again received aortic root injections during reperfusion after anastomosis of the proximal aortovein and distal coronary artery. Echocardiographic images of the left ventricle short axis at the level of the papillary muscles were obtained in real time and analyzed retrospectively from videotape. Injection of contrast provided information about the magnitude and geometric distribution of coronary artery-vein bypass run-off and enabled identification of poorly perfused myocardial regions. When predicted myocardial perfusion patterns, based on preoperative evaluation of epicardial vessel distribution derived from coronary angiography, were compared to actual perfusion patterns assessed with intraoperative echocardiography, contrast regional myocardial perfusion patterns were predicted 84% of the time (71-97%, 95% confidence limit). Regional myocardial perfusion deficits detected after coronary bypass grafting were associated with regional wall motion abnormalities detected after separation from cardiopulmonary bypass. Our technique makes possible on-line visualization of changes in regional blood flow in the heart before, during, and after CABG.(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical treatment of giant cavernous hemangiomas of the liver--analysis of 7 patients

Seven patients with giant cavernous hemangioma of the liver were treated surgically with success at Pusan Gospel Hospital, Kosin Medical College, Pusan, from 1980 through 1989. They were 3 males and 4 females, and their ages ranged from 6 to 59 years. The tumors were located on the right lobe of the liver in 5 patients and on the left lobe in 2. The lesions were solitary in all patients, and their sizes varied from 4cm to 15cm in diameter. All patients underwent hepatic resection: 1 right hepatic lobectomy and 4 partial resections for tumors on the right lobe, and 1 left lobectomy and 1 left lateral segmentectomy for tumors on the left lobe. There was no surgical death, but 1 patient had a postoperative complication: multiple stress ulcers on the stomach and ileum. The pathologic diagnosis was cavernous hemangioma in all cases. In the long-term follow-up, there was no recurrence of preoperative symptoms in any patient.

The mouse Y* chromosome involves a complex rearrangement, including interstitial positioning of the pseudoautosomal region

Cytological analysis of the mouse Y* chromosome revealed a complex rearrangement involving acquisition of a functional centromere and centromeric heterochromatin and attachment of this chromosomal segment to the distal end of a normal Y* chromosome. This rearrangement positioned the Y* short-arm region at the distal end of the Y* chromosome and the pseudoautosomal region interstitially, just distal to the newly acquired centromere. In addition, the majority of the pseudoautosomal region was inverted. Recombination between the X and the Y* chromosomes generates two new sex chromosomes: (1) a large chromosome comprised of the X chromosome attached at its distal end to all of the Y* chromosome but missing the centromeric region (XY*) and (2) a small chromosome containing the centromeric portion of the Y* chromosome attached to G-band-negative material from the X chromosome (YX). Mice that inherit the XY* chromosome develop as sterile males, whereas mice that inherit the Y*X chromosome develop as fertile females. Recovery of equal numbers of recombinant and nonrecombinant offspring from XY* males supports the hypothesis that recombination between the mammalian X and Y chromosomes is necessary for primary spermatocytes to successfully complete spermatogenesis and form functional sperm.

Localization of the growth hormone gene to the distal half of mouse chromosome 11

A DNA fragment size variant for the growth hormone gene, Gh, has been identified among inbred strains of mice. The inbred strains SM/J and CAST/Ei carry the less frequent allele Ghb and 11 other strains carry the Gha allele. Segregation analysis of data from two crosses involving SM/J and NZB/BINJ and a cross involving BALB/cJ and CAST/Ei confirmed the assignment of Gh to mouse chromosome 11 and placed the locus 2.6 +/- 1.8 map units distal to Erba (avian erythroblastosis oncogene A), a position consistent with the assignment of the Gh locus to the q22-q24 region of chromosome 17 on the human map. Segregation analysis also refined the location of Sparc (secreted acidic cysteine-rich glycoprotein) on mouse chromosome 11 to a position 16.7 +/- 4.2 map units proximal to Evi-2 (ecotropic viral integration site 2).

Inheritance of T-associated sex reversal in mice

We previously identified a primary sex-determining locus, Tas, on mouse Chr 17 that causes ovarian tissue development in C57BL/6J Thp/+ and TOrl/+ individuals if the AKR/JY chromosome is present. We hypothesized that Tas is located within the region of Chr 17 deleted by Thp and TOrl and that C57BL/6J carries a diagnostic Tas allele, based on the observation that ovarian tissue develops in XY mice when Thp is on a C57BL/6J inbred strain background, whereas normal testicular development occurs when Thp is on a C3H/HeSnJ inbred strain background. To test this hypothesis, we mated (C57BL/6J x C3H/HeSnJ)F1 females to C57BL/6J Thp/+ hermaphrodites. As expected, half of the XY Thp/+ offspring developed ovarian and testicular tissue while half developed exclusively testicular tissue. Unexpectedly, the inheritance of selected Chr 17 molecular loci was independent of gonadal development, as half of the male and hermaphroditic offspring inherited C3H/HeSnJ-derived Chr 17 loci and half inherited C57BL/6J-derived Chr 17 loci. We conclude that for ovarian tissue to develop in an XY Thp/+ or XY TOrl/+ individual (1) Tas must be present in a hemizygous state, which is accomplished by heterozygosity for the Thp or TOrl deletions; (2) the AKR/J-derived Y chromosome must be present; and (3) an additional locus involved in primary sex determination must be present in a homozygous C57BL/6J state. This newly identified gene may be one of the previously defined loci, tda-1 or tda-2.

Segregation patterns of endogenous mouse mammary tumor viruses in five recombinant inbred strain sets

We identified mouse mammary tumor proviral loci in the AKR/J, C3H/HeJ, C57BL/6J, C57L/J, DBA/2J, and SWR/J inbred mouse strains and determined their segregation patterns in the AKXD, AKXL, BXD, BXH, and SWXL recombinant inbred strain sets. Two new Mtv loci, Mtv-29 and Mtv-30, were identified. Mtv-30 was genetically mapped to chromosome 12. Additionally, two previously identified Mtv loci, Mtv-14 and Mtv-23, were genetically mapped to chromosome 4 and chromosome 6, respectively.

Effect of polyadenylic.polyuridylic acid on the proliferative responsiveness of mouse thymus and spleen cells

The effects of polyadenylic.polyuridylic acid [poly(A).poly(U)] on in vitro proliferations of thymus and spleen cells from C57BL/6 mice were investigated. Mice were injected intravenously with 30 micrograms of poly(A).poly(U) or placebo. Two days later, thymus, spleen and peritoneal cells from these mice were prepared and cultured in pooled or non-pooled conditions. Cell proliferations were assessed by the technique of incorporation of tritiated thymidine. It has been revealed that the in vitro proliferations of thymus and spleen cells as well as the productions of interleukin-1 by peritoneal adhering cells and interleukin-2 by spleen cells were significantly enhanced in the cultures of cells from poly(A).poly(U)-treated mice. These enhancing effects were observed only in the cultures of pooled cells from mice whose genetic homogeneity is suspected. Furthermore, thymus cells from poly(A).poly(U)-treated mice acted as strong responder cells but not as stimulators in one way mixed cultures. Thus, the enhanced cellular responsiveness may be mediated by the increased production of cytokines and antigen recognitions of thymus-derived cells following activations via the adjuvant effect of poly(A).poly(U).

The NXSM recombinant inbred strains of mice: genetic profile for 58 loci including the Mtv proviral loci

We report the construction of 17 recombinant inbred (RI) strains of mice derived from the progenitor strains NZB/BINRe and SM/J and the typing of this RI strain set, designated NXSM, for 58 loci distributed on 16 autosomes and the X chromosome. Two backcrosses involving NZB/BINJ and SM/J were constructed to confirm chromosomal assignments and determine gene orders suggested from NXSM RI strain data. From these results we recommend that chromosomal assignments and gene orders suggested from analyses of RI strain sets be confirmed using data obtained by other means. We also typed NZB/BINJ and SM/J for mammary tumor proviral (Mtv) loci. Both strains share three previously described Mtv loci: Mtv-7, Mtv-14 and Mtv-17. In addition, NZB/BINJ contains the previously described Mtv-3 and Mtv-9 loci and two new Mtv proviral loci: Mtv-27 located on chromosome (Chr) 1 and Mtv-28 located on the X chromosome. SM/J contains the previously described loci Mtv-6 and Mtv-8. Four LTR, mink cell focus-forming murine leukemia viral loci were identified and mapped: Ltrm-1 on Chr 12, Ltrm-2 on Chr 16, Ltrm-3 on Chr 5, and Ltrm-4 on Chr 13. The Tgn locus was positioned proximal to the Ly-6 locus on Chr 15.

The Mos proto-oncogene maps near the centromere on mouse chromosome 4

The Mos proto-oncogene, the cellular homolog of the transforming gene of Moloney murine sarcoma virus, was originally assigned to mouse chromosome 4 using independent panels of mouse/hamster somatic cell hybrids. By in situ hybridization to metaphase chromosomes and standard genetic backcrosses, we have confirmed this assignment and determined that Mos maps near the centromere in a region devoid of other markers. We have also identified a restriction fragment length polymorphism (RFLP) that defines two alleles of the Mos locus in selected inbred strains of laboratory mice. Using the RFLP, we determined the strain distribution pattern for the Mos gene in three sets of recombinant inbred strains and in five strains congenic for histocompatibility antigen genes localized on chromosome 4. These results establish Mos as a useful marker in a poorly characterized region of the mouse genome. In addition, these results will facilitate the genetic analysis of the Mos locus.

A repeated segment on the mouse Y chromosome is composed of retroviral-related, Y-enriched and Y-specific sequences

We report the isolation and characterization of two recombinant clones containing DNA derived from the Y chromosome of the C57BL/10 inbred mouse strain. Both clones were isolated from a lambda phage library derived from a partial EcoRI digest of C57BL/10 male DNA using the murine retrovirus M720. Characterization of these clones showed they were derived from a repeated segment present on the C57BL/10J Y chromosome that contains sequences found elsewhere in the genome. In addition, one clone contained a sequence, designated YB10, that is unique to the Y chromosome and present in approximately 500 copies on the C57BL/10J Y chromosome. Analysis of Southern blots containing DNAs prepared from females and males of representative species from four subgenera of Mus probed with pYB10 and the 3'LTR from one of the Y-associated retroviruses (MuRVY) revealed that, with the exception of a single fragment observed in both female and male DNA of Mus saxicola, hybridization to pYB10 was observed only to male DNA of the species Mus spretus, Mus hortulanus, Mus musculus, Mus domesticus and Mus abbotti. In addition, the pattern and intensity of hybridization to YB10 and the MuRVY-LTR indicated that sequence of divergence was followed by amplification of Y chromosome sequences containing YB10 and MuRVY. The divergence and amplification occurred separately in each of the ancestral lineages leading to M. spretus, M. hortulanus, M. abbotti, M. musculus and M. domesticus. We suggest that acquisition and amplification of DNA sequences by the mammalian Y chromosome has contributed to its evolution and may imply that the mammalian Y chromosome is evolving at a faster rate than the rest of the genome.

Blood cadmium levels in the populations of Masan, Korea, and Miyagi, Japan: an inter-regional comparison

Blood samples were collected from factory workers (with no occupational exposure to metals including cadmium) in Masan (167 subjects), Korea, in 1986, and Miyagi prefecture (270 subjects) Japan, in 1987. The samples were analyzed for cadmium in a single laboratory by flameless atomic absorption spectrophotometry under strict quality control. The effect of aging was detected in Masan and possibly also in Miyagi. The effect of smoking was evident among male smokers in Miyagi. Comparison with findings in a sister study on blood cadmium levels in China (taking the effects of smoking and aging into account) showed regional differences: the levels were lower in China, higher in Korea and probably highest in Japan. The smoking-associated increase in blood cadmium level per cigarette was 2-3 times higher in China than in Japan. The blood cadmium levels in the study regions appeared to be associated with the cadmium content of local rice as well as with local rice-eating habits.

Y chromosome evolution in the subgenus Mus (genus Mus)

A 305 base pair DNA sequence isolated from the Y chromosome of the inbred mouse strain C57BL/10 was used to investigate the pattern and tempo of evolution of Y chromosome DNA sequences for five species in the subgenus Mus, including Mus spretus, Mus hortulanus, Mus abbotti, Mus musculus and Mus domesticus. Variation in hybridization patterns between species was characterized by differences in fragment lengths of both intensely and faintly hybridizing fragments, whereas variation in hybridization patterns within species was characterized primarily by differences in fragment lengths of faintly hybridizing fragments. Phylogenetic analyses were conducted based on fragment size variation within and among species. Phylogenetic relationships inferred from these analyses partly agree with the phylogenetic relationships obtained from biochemical and mitochondrial DNA data. We conclude that a set of DNA sequences common to the Y chromosomes of a closely related group of species in the subgenus Mus has evolved rapidly as reflected by sequence divergence and sequence amplification.

Hepatitis B virus infection among women in a shoe factory in Korea

One hundred and sixty five Korean women in a shoe factory in Masan, Korea were evaluated on hepatitis B virus infection by solid-phase radioimmunoassay in 1986. The participants were women of child-bearing ages, mostly in 20's and 30's. About two thirds (105/165) of the subjects had serological evidence of past or present hepatitis B virus infection, and 17% (28/165) were HBsAg-positive. In view of possible risk of vertical transmission of hepatitis B virus, further epidemiological study was considered necessary to establish preventive measures.

Mapping of the mouse Ly-6, Xp-14, and Gdc-1 loci to chromosome 15

The Ly-6 locus is now regarded as a gene complex consisting of at least five closely linked loci (Ly-6A-Ly-6E) whose polymorphic products are identified by monoclonal antibodies and distinguished by different tissue distributions. Ly-6 has been assigned by other investigators to chromosome (Chr) 9 (linked to Thy-1) or to Chr 2. We report that the Ly-6 gene complex, together with the Xp-14 and Gdc-1 loci, is situated on Chr 15 linked to Gpt-1. These new linkage data are derived from four sources: (1) three separate crosses that failed to demonstrate linkage of Ly-6 to either Thy-1 on Chr 9 or to any of five genes present on Chr 2; (2) the NXSM recombinant inbred strains, which suggested the linkage of Ly-6 and Xp-14 to Gpt-1 on Chr 15; (3) several Gpt-1 and Gdc-1 congenic strains that confirmed the assignment of Ly-6 and Xp-14 to Chr 15; and (4) backcrosses that further confirmed the linkage of Ly-6, Gpt-1, Gdc-1, and Xp-14, the probable gene order being Gpt-1/Ly-6-Xp-14-Gdc-1.

Functional and metabolic evidence of enhanced myocardial tolerance to ischemia and reperfusion with adenosine

An isolated, isovolumetrically contracting rat heart preparation, perfused at constant flow, was used to test the hypothesis that adenosine treatment (100 microM) throughout the experiment could enhance the repletion of adenosine triphosphate and the recovery of ventricular function following 10 minutes of global, normothermic (37 degrees C) ischemia. Left ventricular developed pressure was measured with an intraventricular balloon, and myocardial adenine nucleotides were measured from freeze-clamped tissues in a parallel series of experiments. The adenosine triphosphate level in the adenosine-treated hearts was not different from that of the untreated control hearts at the end of 30 minutes of equilibration but was significantly (p less than 0.05) higher at the end of 10 minutes of ischemia and at 15, 30, and 60 minutes of reperfusion. Left ventricular developed pressure in the adenosine-treated group at the end of 30 minutes of equilibration (92 +/- 3 mm Hg) was not significantly different from that of the control hearts (101 +/- 10 mm Hg). During the reperfusion period the control group returned to 75% +/- 7%, 73% +/- 6%, and 73% +/- 6% of the preischemic control function at 15, 30, and 60 minutes of reperfusion, respectively. The adenosine-treated group had significantly greater return of function to 86% +/- 3%, 96% +/- 3%, and 95% +/- 3% of the preischemic control at 15, 30, and 60 minutes of reperfusion, respectively. In a protocol to assess the effect of adenosine during ischemia, we found that adenosine (100 microM) increased the time to onset of ischemic contracture by 50% from 12 +/- 3 to 18 +/- 3 minutes and decreased the rate of net adenosine triphosphate degradation. Our data suggest that under these experimental conditions, adenosine enhances myocardial preservation by reducing the net degradation of adenosine triphosphate during ischemia and facilitating the repletion of adenosine triphosphate during reperfusion.

Interactions of manganese(II) and small ligands with Busycon canaliculatum hemocyanin

Cyanide (5 X 10(-3) M) and thioacetamide (5 X 10(-3) M) increase the P50 values (P02 required for 50% oxygenation) of hemocyanin by 100%, respectively. Using an ion-exchange method involving 14CN-, we have found that cyanide forms a 1:1 complex with hemocyanin in the concentration range examined: Kf = 2.3 X Mw M-1 at room temperature, where Kf is association constant and Mw is molecular weight of hemocyanin. This strong binding of cyanide to hemocyanin is to be expected from the effect of this ion on the oxygenation of hemocyanin. The effects of manganese(II) ion and fluoride on the oxygenation of hemocyanin are found to be weak. The nmr measurements, however, suggest that manganese(II) ion does have some interactions with the active site of hemocyanin.

The hazimicins, a new class of antibiotics. Taxonomy, fermentation, isolation, characterization and biological properties

The hazimicins, a new class of broad spectrum antibiotics with at least 2 active components (5 and 6), were isolated from the fermentation of Micromonospora echinospora var challisensis SCC 1411. The complex was separated from the broth by a solvent extraction procedure, and the individual components were separated by column chromatography. The two primary active components are isomers, with unique structures shown to be di-tyrosine analogs containing two isonitrile groups. The antibiotic has in vitro activity against Gram-positive and Gram-negative bacteria, and in vitro activity against yeasts and dermatophytes.

Association of the lethal yellow (Ay) coat color mutation with an ecotropic murine leukemia virus genome

The dilute (d) coat color mutation on chromosome 9 is closely associated with an ecotropic murine leukemia virus (MuLV) genome [Jenkins, N.A., Copeland, N.G., Taylor, B.A. & Lee, B.K. (1981) Nature 293, 370-374]. DBA/2J mice homozygous for the reverse mutation to wild type at the dilute locus (d+2J) lack ecotropic virus-specific sequences, suggesting that the dilute mutation was caused by virus integration. In the experiments described here, we analyzed the ecotropic MuLV DNA content of mice that collectively carry 10 different alleles at the agouti coat color locus (of chromosome 2) to determine whether any of these alleles also are associated with ecotropic virus sequences. Of the 10 alleles analyzed, one allele, lethal yellow (Ay), which is carried congeneically and heterozygously on C57BL/6J, 129/Sv, and LT/Sv mice, was closely associated with an ecotropic MuLV provirus. The close association of this provirus with the Ay allele suggests that this mutation also may be caused by virus integration. Furthermore, this association may be useful for molecular cloning and characterizing the many alleles at this locus.

Occupational lead exposure of storage battery workers in Korea

Two hundred and thirty-four lead workers employed in a storage battery factory in Korea were examined for lead in blood (PbB) and urine (PbU). delta-aminolaevulinic acid in urine (ALAU), coproporphyrin in urine (CPU), and haemoglobin. The dose-response relationship between PbB and ALAU suggested that a PbB below 50-60 micrograms/dl is a proper practical limit of biological monitoring for lead workers. The inter-relationship between PbB and ALAU or PbU was better explained by a segmental straight function than by a curvilinear function. Inclusion of data from workers whose PbB was below 30-40 micrograms/dl, if they comprise a relatively large proportion of the whole, seems to have a role as a dummy effect on the overall regression function causing the curvilinear trend. At a given blood lead concentration, the ALAU of lead workers increased with an increase in the duration of exposure. This could be explained by the chronic effect of lead on haem precursors. Semi-quantitative measurement of CPU still played an important part in the screening of lead workers due to its simplicity, showing high sensitivity (97.8%) in detecting lead workers with PbB of 60 micrograms/dl or over.

Organization, distribution, and stability of endogenous ecotropic murine leukemia virus DNA sequences in chromosomes of Mus musculus

The endogenous ecotropic murine leukemia virus DNA content and integration sites were characterized for 54 inbred strains and substrains of mice by restriction enzyme digestion, Southern blotting, and hybridization with an ecotropic murine leukemia virus DNA-specific probe. More than 75% of these strains carried endogenous ecotropic proviruses which were located in at least 29 distinct integration sites in chromosomes of Mus musculus. Fourteen of these proviruses have been assigned specific locus designations. Most, but not all, of the endogenous ecotropic proviruses were structurally indistinguishable by this analysis from the prototype AKR ecotropic virus, and the distribution of these proviruses followed known relationships among the inbred strains and substrains of mice. These results suggest that, in general, viral DNA integration preceded the establishment of inbred mouse strains and that these integrations are relatively stable.

Ecotropic murine leukemia virus DNA content of normal and lymphomatous tissues of BXH-2 recombinant inbred mice

BXH-2 recombinant inbred mice spontaneously produce a B-tropic murine leukemia virus (MuLV) beginning early in life and have a high incidence of non-T-cell lymphomas. These traits are not characteristic of the progenitor strains (C57BL/6J and C3H/HeJ) or of 11 other BXH recombinant inbred strains. Since B-tropic virus expression may be causally related to the high incidence of lymphoma in this strain, we have analyzed the ecotropic MuLV DNA content of both normal and lymphomatous tissues of BXH-2 mice. Southern analysis and hybridization with an ecotropic MuLV DNA-specific probe showed that DNA of normal BXH-2 tissues contained both parental N-tropic MuLV proviruses but lacked endogenous B-tropic MuLV DNA sequences. In addition, none of 116 F1 hybrid mice derived from male BXH-2 mice spontaneously produced ecotropic MuLV early in life. These results suggest that the B-tropic virus is horizontally transmitted in BXH-2 mice. Southern analysis of DNA from tumor tissues of 12 BXH-2 mice showed that amplification of ecotropic-specific DNA sequences had occurred in lymphomatous tissues of 3 mice and suggested that these tumors were monoclonal. The number of newly acquired proviruses, which appeared to be structurally nondefective and integrated at different sites, varied from one to three copies. Since lymphomatous tissues from only 3 of 12 mice examined carried additional detectable ecotropic proviruses, these results suggest that amplification of ecotropic MuLV DNA sequences is not required for maintenance of transformation in BXH-2 lymphomas.

Dilute (d) coat colour mutation of DBA/2J mice is associated with the site of integration of an ecotropic MuLV genome

The single endogenous DBA/2J ectropic provirus segregated concordantly with the dilute (d) coat colour mutation on chromosome 9 in 53/53 DBA/2J-derived recombinant inbred mouse strains and all seven inbred and mutant strains tested that carry the d allele. Analysis of DNA from a spontaneous DBA/2J d revertant (d+2J) showed that these mice lack ecotropic-specific MuLV DNA sequences and suggested that the dilute mutation resulted from integration of an ecotropic provirus into the mouse genome.

Kijanimicin (Sch 25663), a novel antibiotic produced by Actinomadura kijaniata SCC 1256. Fermentation, isolation, characterization and biological properties

A novel antibiotic complex has been isolated form the fermentation broth of a new species of Actinomadura, A. kijaniata SCC 1256. The complex was separated form the broth by a solvent extraction procedure and consists of 1 major component, designated kijanimicin, and 3 minor components. Kijanimicin was isolated form the complex by column chromatography and/or preparative high pressure liquid chromatography. Structurally the compound is a unique, large acid enol antibiotic and possesses an unusual in vitro spectrum of activity against some Gram-positive and anaerobic microorganisms. In vivo it has also shown interesting activity against malaria.

Tetanus and diphtheria immunity in urban Minnesota adults

Tetanus and diphtheria antitoxin levels were measured in 183 urban adults, using a hemagglutination technique. Protective levels (greater than 0.01 unit/mL) of tetanus antitoxin were present in more than 85% of sera from all subjects under 40 years of age and from men between 40 and 59 years old. A minority of women (36%) between 40 and 59 years of age, and of men (41%) and women (29%) over 60 years of age, were protected. Less than one quarter of the study group had protective levels (greater than 0.01 unit/mL) of diphtheria antitoxin. The results of the study suggest that a minority of middle-aged women and older adults have been appropriately immunized against diphtheria and tetanus.

Biosynthetic pathway leading to gentamicin C2b

Incubation of Micromonospora purpurea SC 1210 (NRRL 5467) with L-[methyl-14C]methionine yielded [methyl-14C]gentamicin A and methyl-14C-labeled antibiotic JI-20A in a molar radioactivity ratio of 9:2. We did not isolate methyl-14C-labeled gentamicin X2, which was expected as an intermediate based on the biosynthetic pathways proposed by others. Addition of methyl-14C-labeled antibiotic JI-20A to M. purpurea SC 1124 (NRRL 8102) yielded [methyl-14C]-gentamicin C1a and [methyl-14C]gentamicin C2b in variable molar radioactivity ratios. These data do not support the biosynthetic pathway leading to gentamicin C2b proposed by Testa and Tilley.

Shear vs pressure as causative factors in skin blood flow occlusion

An instrument was developed to measure the external pressure, shear, and pulsatile arteriolar blood flow existent at a given portion of the anatomy. Application of this device to the thenar eminence of 4 healthy subjects showed that externally applied pressure was approximately twice as effective as shear in reducing pulsatile arteriolar blood flow. The combination of pressure plus shear was found particularly effective in promoting blood flow occlusion. At a sufficiently high level of shear (roughly 100 g/cm2) the pressure necessary to produce occlusion was half that required when little shear was present.

The association between Staphylococcus aureus bacteremia and bacteriuria

The relationship between Staphylococcus aureus bacteremia and bacteriuria was studied over a five year period in three hospitals. In a Veterans Administration Hospital, 59 patients with Staph, aureus bacteremia had a urine culture within 48 hours of a positive blood culture. In 16 of 59 (27 per cent), greater than 10(5) Staph. aureus was recovered from the urine in pure culture. Six of these patients had apparent primary staphylococcal urinary tract infection. Clinical and laboratory parameters in the patients with staphylococcal bacteremia and bacteriuria were compared with those in 31 patients with staphylococcal bacteremia and sterile urine cultures. The two groups differed only in the more frequent occurrence of pyuria and proteinuria in the bacteriuric patients. In two other hospitals, staphylococcal bacteriuria occurred in 7 per cent of patients with Staph. aureus bacteremia and in 13 per cent of cases of staphylococcal endocarditis. Review of autopsy records for 33 patients who died within one month of their bacteremia failed to show a correlation between bacteriuria and the presence of renal abscess. Staphylococcal bacteriuria is a frequent and unexplained concomitant of Staph. aureus bactremia.

Antibiotic biosynthesis by cofermentation of blocked mutants of two Micromonospora species

Two aminocyclitol-negative Micromonospora mutants representing two different species, M. purpurea and M. inyoensis, and blocked at different steps in the biosynthetic pathway were paired and cofermented for the synthesis of antibiotics. The two blocked mutants were incapable of producing antibiotics alone except when 2-deoxystreptamine was added. When combined they produced gentamicins A, X(2), C(1a), and C(2b), which all have an amino group at the 2' position, and gentamicin B, which has a hydroxyl group at this position instead.

Method for qualitative determination of 2-deoxystreptamine

We have developed a qualitative method to assay for the presence of 2-deoxystreptamine in hydrolysates of crude aminoglycoside preparations using a 2-deoxystreptamine-requiring idiotrophic mutant. The assay involves (i) incubation of a 2-deoxystreptamine-requiring mutant with 1 mg of a hydrolyzed preparation from a crude unknown antibiotic mixture per ml, and (ii) examination of the resultant incubation mixture for production of antibiotic(s) by disk assay.

Uptake of (methyl-14C)-sisomicin and (methyl-14C)-gentamicin into bacterial cells

Eight sensitive strains (two Staphylococcus aureus, two Escherichia coli, two Pseudomonas aeruginosa and two Klebsiella pneumoniae) and four resistant Pseudomonas aeruginosa strains were used to study uptake of sisomicin and gentamicin by the bacterial cells. In eleven out of the twelve organisms studied employing (methyl-14C)-sisomicin and (methyl-14C)-gentamicin, uptake of the former was found higher that that of the latter. In one organism, the uptake of the two antibiotics was similar. This higher uptake of sisomicin may help explain the superior potency of the antibiotic in relation to gentamicin.

Biotransformation of sisomicin to gentamicin C2b

Sisomicin was transformed to gentamicin C(2b) by Micromonospora rhodorangea NRRL 5326. The mechanisms involved in the biotransformation are the 6'-N-methylation and the (4'-5')-reduction. The progression of the methylation was followed by the isotope technique, but the reduction reaction was not monitored.

Synthesis and biological activity of (2-hydroxy-1-naphthyl)-methylamino acetamido-epicillin and cephradine, and (2-hydroxy-1-naphthyl)-methylacetamido 6-APA

Two new penicillins and a new cephalosporin have been synthesized by condensing 2-hydroxy-1-naphthaldehyde with epicillin, 6-aminopenicillanic acid and cephradine, and subsequently reducing the SCHIFF bases with NaBH4. The antimicrobial activities of these compounds are also described.

Formation of methylated and phosphorylated metabolites during the fermentation process of verdamicin

In an attempt to understand the biosynthetic processes leading to the formation of verdamicin (end product), we have examined the patterns of the formation of methylated and phosphorylated metabolites, which resulted from either the addition of l-[methyl-(14)C]methionine or [(32)P]KH(2)PO(4) to the fermentation. Incorporation of label from l-[methyl-(14)C]methionine into the bioactive sisomicin, verdamicin, and the chromatographically polar components increased with the progression of time. Two methylated bioinactive metabolites were found in the culture broth after removal of the methylated bioactive metabolites. In contrast to the bioactive metabolites, incorporation of the methyl-(14)C label into the two methylated bioinactive metabolites decreased with the progression of time. A phosphorylated bioinactive metabolite (nonmethylated) was also found in the culture broth, fermented in the presence of [(32)P]KH(2)PO(4). The role of the phosphorylated metabolite in the biosynthesis of the bioactive metabolites cannot yet be explained.

Micromonospora-produced sisomicin components

A sisomicin fermentation carried out in the presence of (methyl-14C)-L-methionine resulted in a crude mixture, composed of methyl-14C-labeled sisomicin as a major component; and two 4''-C-desmethylsisomicin (66-40B and 66-40D) isomer-like components, an unidentified component and a gentamicin A-like antibiotic as minor components. When (methyl-14C)-L-methionine was added in an early stage of the fermentation (24 hours), incorporation of methyl-14C-label into polar components (e.g., gentamicin A-like antibiotic) preceded that into sisomicin. Chromatographic evidence for the bioconversion of (methyl-14C)-gentamicin A to a radioactive sisomicin-like product (possibly (3''-N-methyl-14C)-sisomicin) was seen, when a Micromonospora blocked mutant was incubated in the presence of the former antibiotic.

Micromonospora-produced gentamicin components

After the chromatographic separation of [methyl-(14)C]gentamicin major (C) components from a large-scale radioactive fermentation (Lee et al., 1974), [methyl-(14)C]gentamicin minor (polar) components (A, B, B(1), X(2), and G-418) were isolated from subsequent chromatography of the remaining antibiotic mixture. When l-[methyl-(14)C]methionine was added at the onset of biosynthesis of the gentamicin components, incorporation of label into the minor components preceded incorporation into the major components. Degradation occurred when [methyl-(14)C]gentamicin major components (C(1), C(2) and C(1)a) were added respectively to the gentamicin-producing culture medium and shaken.

Mouse mammary tumor virus polypeptide precursors in intracytoplasmic A particles

Intracytoplasmic A particles were analyzed by immunodiffusion and sodium dodecyl sulfate--polyacrylamide gel electrophoresis (SDS--PAGE) before and after enzymatic cleavage with trypsin. A common antigen in A particles was detected by antisera prepared against purified intracytoplasmic A particles, purified mouse mammary tumor virus (MMTV), and a purified MMTV core polypeptide (p28). Despite this correlation, no SDS--polyacrylamide band migrating at p28 was observed in purified intracytoplasmic A particles. However, after incubation with trypsin, A particles subjected to SDS--PAGE produced only two polypeptide bands. They were observed at p28 and p15-10. Ouchterlony analysis of the trypsin-cleaved A particles revealed no alteration in the antigenicity of the particles. These results suggested that some structural components of intracytoplasmic A particles are polypeptide precursors of MMTV core proteins.