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Consequences of amniotic fluid infections: early neonatal septicaemia.

This study describes the results of examination of blood cultures from infants born in a community with a high prevalence of fatal amniotic fluid infection. The incidence of first-week neonatal septicaemia was 5.5 per 1000 births. Septicaemia was detected in 38% within 12 hours and 75.6% within 72 hours of birth. The aetiological pattern of the septicaemia was similar to that of fatal amniotic fluid infections. The increase in mortality from septicaemia occurred in infants born after 34 weeks of gestation. Nearly 80% of the infections apparently occurred through intact membranes. Respiratory distress with or without radiological evidence of pneumonia was the only manifestation of septicaemia in most infants under four days of age. Low Apgar scores and multiple apnoeic episodes were more common in infants with septicaemia than in those without septicaemia. Neonatal jaundice with serum bilirubin in excess of 11 mg/dl was more common in septicaemic infants and indicated poor prognosis. Meningitis associated with septicaemia occurred in 3.8% and in all these infants the diagnosis of septicaemia was delayed beyond 72 hours. The results suggest that early recognition and treatment of antenatal bacterial infections may prevent mortality and morbidity from complications of septicaemia such as neonatal apnoea, meningitis and bilirubin encephalopathy.

Amniotic Fluid

Genes required for Mycobacterium tuberculosis to survive the transition from aerosol to pulmonary alveolar lining fluid and early infection in a model of transmission.

Mycobacterium tuberculosis (Mtb) must withstand physical and chemical stresses during airborne transmission, including during the desiccation of aerosols small enough to reach pulmonary alveoli in a new host. There, Mtb encounters an antimicrobial pulmonary alveolar lining fluid (ALF) before it is engulfed by macrophages. To study the genes involved in Mtb's ability to survive the transition from desiccated droplet to pulmonary alveolus in an in vitro model, we formulated a model alveolar lining fluid (MALF) that mimics the composition of ALF as inferred from human bronchoalveolar lavage fluid (BALF). We compared the transcriptome of log-phase Mtb in MALF to the transcriptome of Mtb in BALF as BALF from the lungs of healthy adults was reconstituted to compensate for the dilution of ALF by lavage (rcBALF). Mtb from log-phase culture in a standard laboratory medium survived quantitatively in MALF and rcBALF for at least 24 hours. In contrast, Mtb that had passed through earlier stages of transmission began to succumb after 3 hours in MALF, past the time when particles have been observed to be phagocytized by alveolar macrophages. Screening of a genome-wide CRISPRi library of Mtb identified 35 genes as uniquely required by Mtb to survive the transition from desiccated microdroplet into rehydration in MALF. Thirty-one of these genes are non-essential under conventional laboratory conditions and seven have unknown functions. Thirteen of the 35 genes were additionally required for Mtb to survive in macrophage-like cells cultured at the air-liquid interface with pulmonary epithelial cells. This study nominates additional members of the transmission survival genome of Mtb, illustrates that different genes may contribute to the survival of Mtb at different stages of transmission, and suggests that modeled transmission can shed light on the functions of Mtb genes whose contributions have been unknown.

Journal Article

Extent of transcription of the E strand of polyoma virus DNA during the early phase of productive infection.

Early polyoma virus-specific RNA, in nuclei and cytoplasm of cells labeled with [(3)H]uridine, was analyzed by hybridization with filter-bound Hpa II fragments of polyoma DNA. About 40% of labeled cytoplasmic virus-specific RNA hybridized with Hpa II fragment 2, which represents about 40% of the region coding for E-strand mRNA's; less than 5% hybridized with fragments 1 or 3, which lie outside this region. A somewhat lower proportion (about 30%) of labeled nuclear virus-specific RNA hybridized with fragment 2, and a small but significant fraction (7 to 14%) hybridized with fragments 1 and 3. About two-thirds of the nuclear RNA which hybridized to fragment 1 was complementary to the E strand, and one-third was complementary to the L strand. Results did not vary greatly in samples labeled for periods of from 15 min to 3 h. The major species of pulse-labeled nuclear polyoma-specific RNA sedimented at 22S and thus is slightly larger than the 19S cytoplasmic mRNA. These results show that most early nuclear RNA ( approximately 75%) is transcribed from the region of the E strand, which codes for early mRNA's, and that there is probably a site at which transcription is terminated at the end of this region. However, a small amount of early nuclear RNA ( approximately 15%) is transcribed from the remainder of the E strand, perhaps by readthrough of this termination signal. In addition, there is a small amount of transcription from the L strand, whose significance is unclear. Neither the L-strand transcripts nor the nonmessenger E-strand transcripts are transported to the cytoplasm.

DNA, Viral

[Effect of Mycoplasma arthritidis on mouse and rat lymphoid cells in experimental Mycoplasma infection].

Early stages of mycoplasma infection of mice and rats were accompanied by suppression of the populations of rosette- and plaque-forming cells. Later the character and dynamics of the immune response to M. arthritidis differed in mice and rats. In mice mycoplasma infection was accompanied by stimulation of rosette-forming cells with some suppression of the plaque-forming cells from the 7th to the 36th day of infection. In rats by the 7th day the number of plaque- and rosette-forming cells decreased in comparison with control, and the immune response was restored by the 15h day; at later periods the immune response of the infected rats exceeded the normal level considerably. The cellular and humoral immune reactions proved to depend on the mycoplasma dose.

Animals

Protein synthesized early after infection is linked to the termini of adenovirus type 2 DNA synthesized in vivo and in vitro.

The human adenovirus DNA genome contains a protein (CBP, or covalently bound protein) linked to each 5' terminus. To assess whether CBP is synthesized early, infected cells were incubated with hydroxyurea from 1 to 18 h postinfection, the hydroxyurea was removed, cycloheximide was added, and viral DNA was labeled with [3H]thymidine from 18 to 23 h postinfection. Removal of hydroxyurea at 18 h postinfection permits the synthesis of viral DNA, whereas cycloheximide maintains the block in late viral protein synthesis. Three lines of evidence are presented to show that viral 3H-labeled DNA prepared by this procedure was linked to CBP: (I) the DNA sedimented more rapidly than protein-free DNA (i.e., protinase treated) in neutral sucrose gradients containing guanidine hydrochloride; (ii) the DNA banded at a lower density than protein-free DNA in CsCl gradients containing guanidine hydrochloride; and (iii) neither the 3H-labeled DNA nor the end fragments produced by EcoRI digestion entered a 1.4% agarose gel during electrophoresis. These experiments are strong evidence that CBP is not a product of a late viral gene and is therefore the product of either an early viral gene or a cell gene. Experiments were performed to test whether CBP is attached to viral DNA synthesized in vitro by a soluble complex that synthesizes exclusively viral DNA as completed viral genomes in vitro. In vitro-labeled DNA was analyzed by velocity sedimentation, equilibrium sedimentation, and agarose gel electrophoresis as described above. Our results indicate that the majority of in vitro-synthesized DNA molecules were attached to CBP. These results, which indicate that CBP is synthesized early after infection and is attached to viral DNA labeled in vitro by a soluble replication complex, are consistent with the idea that CBP may play a role in viral DNA replication.

Adenoviruses, Human

Stimulation of synthesis of the proteins of 30-S nuclear ribonucleoprotein particles in human amnion U cells by viral infection.

Early increase in RNA synthesis induced in human amnion U cells by infection with poliovirus is accompanied by an increased incorporation of amino acids into non-histone nuclear proteins with an approximate molecular weight of 40 000. These proteins are the main polypeptides of the 30-S nuclear ribonucleoprotein particles. After fractionation of nuclear proteins by extraction with solutions of different ionic strength, these polypeptides are present in the fraction of nuclear sap proteins soluble in 0.1 M Tris - HCl buffer, pH 7.6, and in the fraction of non-histone chromosomal proteins which are soluble in 0.35 M NaCl. The increase in synthesis of non-histone nuclear proteins with an approximate molecular weight of 40 000, observed in the infected cells, represents an increase in the synthesis of proteins concerned with post-transcriptional events and, therefore, is the result and not the cause of gene activation.

Carbon Radioisotopes

Bacteremia, endocarditis, and the Hancock valve.

Among 373 patients with porcine xenografts, there were 27 instances of exposure of the xenograft to bloodstream or endocardial infection in 22 patients. Nine patients underwent 10 separate insertions of xenografts for active infective endocarditis. There were no early infections or valve failures. Three patients returned with a late prosthetic valve endocarditis (PVE) due to a new infection. There were 6 instances of bacteremia early after xenograft valve insertion with no early infection, no valve dysfunction, and 1 instance of late PVE. Eleven patients had PVE on a porcine xenograft. Blood cultures in the 10 patients treated with antibiotics promptly became negative. There were 3 valve-related deaths: 2 from valve incompetence and 1 from mitral and aortic xenograft stenosis. Our experience suggests that the Hancock porcine xenograft is: (1) as resistant to infection as are rigid prostheses in active infective endocarditis; (2) resistant to early postoperative bacteremias; and (3) easier to sterilize than rigid prostheses and more durable than other tissue valves in the face of PVE.

Adult

Polypeptide phosphorylation in adenovirus-infected cells.

Cells infected with human adenovirus type 5 have been labelled with 32P-orthophosphate under various conditions and extracts examined, after denaturation in sodium dodecyl sulphate (SDS), by polyacrylamide gel electrophoresis (PAGE) followed by autoradiography. A number of polypeptides appear to be phosphorylated specifically as a result of infection. Early in infection, phosphorylation of a polypeptide of apparent mol. wt. 26 K associated with ribosomes can be detected. Two other phosphorylated polypeptides of apparent mol. wt. 72 K and 18 K can also be seen, the former being mainly confined to the nucleus and capable of being precipitated by the previously described virus-specific P antiserum. The 18 K phosphorylated polypeptide is found mainly in association with membrane fractions. Later in infection phosphorylated polypeptides of apparent mol. wt. 100 K and 39 K can be recognized, the former being associated with ribosomes but removed, however, with a high salt wash; the latter component is mainly detected in the nucleus. Analysis of the purified 32P-labelled virus by the SDS PAGE technique indicated that a structural polypeptide of apparent mol. wt. 66 K (IIIa) was also phosphorylated.

Adenoviruses, Human

Infection following total hip replacement in a general hospital without special orthopaedic facilities.

Infection following total hip replacement is a serious complication for it is frequently impossible to resolve without removal of the prosthesis. We have reviewed 321 total hip replacements undertaken in a general hospital without special orthopaedic theatres. There were 17 deep infections, nine early and eight late. Athough the diagnosis of early infection is usually not difficult, the differentiation between late infections, mechanical failure and metal sensitivity may be a problem. This paper discusses the use of ESR, radiographs, isolation of pathogenic organisms and bone scanning in reaching the diagnosis of infection of the hip. There is possibly a parallel between prosthetic infection and subacute bacterial endocarditis. Therefore all intercurrent infections and episodes of trauma should be given an adequate course of a broad spectrum antibiotic. Sterile air and laminar flow systems are discussed and compared with prophylactic antibiotics, both systemic and local, in attempting to reduce the overall rate of infection following total replacement of the hip.

Adult

The epidemiology of avian lymphoid leukosis.

Avian lymphoid leukosis can be induced by lymphoid leukosis viruses belonging to Subgroups A, B, C, and D. The endogenous virus of the chicken (Rous-associated virus type 0) belongs to Subgroup E and has little, if any, potential for inducing lymphoid leukosis. Nearly all chicken flocks are infected with Subgroup A lymphoid leukosis virus. This virus can be transmitted from dam to offspring or by contact with infected birds. Early infection, either by congential means, or soon after hatching, leads to the highest incidence of lymphoid leukosis. Maternal antibody or genetic resistance to infection delays or prevents infection, leading to a lower incidence of disease. In flocks segregating for genetic resistance to infection, continued infection is maintained through dynamic interactions between genetic resistance, acquired or maternal antibody ,and virus infection. Expression of endogenous viral information is controlled by dominant genes, but spontaneously produced Rous-associated virus type 0 can spread through a susceptible flock and be transmitted like an exogenous virus.

Animals

Regulation of simian virus 40 transcription: sensitive analysis of the RNA species present early in infections by virus or viral DNA.

We have examined the discrete species of simian virus 40 (SV40) RNA present very early in infection of monkey cells with wild-type virus, with mutant tsA58 virus, and with the corresponding DNAs to distinguish between two classes of models for control of late transcription: (i) positive control mediated by large-T antigen and (ii) negative control mediated by a repressor protein associated with viral DNA in the virion. Total cytoplasmic or nuclear polyadenylated RNAs from infected cells were denatured with glyoxal, separated by electrophoresis on agarose gels, and transferred to diazobenzyloxymethyl paper. The positions of specific early and late RNA species were determined with region-specific SV40 DNA probes. The technique can detect individual RNAs present at the level of less than one copy per cell. After 9.5 h at 37 degrees C, appreciable amounts of two early RNAs (2.6 kilobases [kb] and 2.9 kb) were present in the cytoplasm of cells infected with wild-type virus or DNA, along with much smaller amounts of two late RNAs, 1.6 kb (16S) and 2.5 kb (19S). The amounts of the late RNAs were reduced, but they were still synthesized in the presence of cytosine arabinoside, an inhibitor of DNA synthesis. In comparable infections with tsA58 virus or DNA at nonpermissive temperature (41 degrees C), substantial amounts of the two early RNAs were again present, but the two late RNAs could not be detected. However, small amounts of the late RNAs were found when infections with tsA58 virus or DNA were prolonged to 30 h at 41 degrees C. These results are not consistent with negative control of late transcription through the action of a repressor and, taken together with other data, suggest that T antigen has an active role in late RNA synthesis. Specific early and late viral RNAs were also detected in the nuclear poly(A)(+) fractions and were similar in size to the RNA species found in the cytoplasmic polyadenylated fractions. The late nuclear RNAs (1.8 and 2.9 kb) were significantly larger than the late cytoplasmic species, possibly because they are precursors. The 2.6- and 2.9-kb early RNAs found in the cytoplasm are probably the messengers for large-T and small-t antigens, respectively.

Animals

Urinary infection in kidney transplantation.

Urinary tract infection is the most frequent complication following renal transplantation and is important in the etiology of post-transplantation sepsis. The 87 renal homografts done in 1974 at The New York Hospital-Cornell Medical Center were reviewed retrospectively, with at least one year follow-up, in all cases, with particular attention to factors relating urinary tract infection to ultimate success or failure of the renal graft. The over-all incidence of urinary tract infection was 61%. Early infection was associated with a particularly poor prognosis for graft survival. Most patients with urinary infections after successful transplantation experience a combination of both early and late infections. Anatomic factors constitute a remediable cause of urinary infections after transplantation and should be searched for in cases of multiple, recurrent infections, de novo hypertension, or deterioration of previously stable graft function. There were significant differences in the bacteriologic spectrum of urinary tract infections associated with successful transplants as opposed to unsuccessful transplants.

Adult

[Urinary tract infection in early infancy, study of 15 cases].

Urinary tract infection in the newborn shows peculiar characteristics not found in older children. 15 cases of urinary tract infection in infants aged 7 days to 2 months are presented. There is higher incidence in males (11 m./4 f.). Severe clinical picture diverse and undefined clinical course, incidence of jaundice radiological findings and posterior evolution are specially noted. Early diagnosis and effective management lined in base to evolution and prognosis. Hospital stay varied between 2 and 12 weeks. No deaths were registered.

Age Factors

Properties of oncornavirus RNA-directed DNA polymerase, the RNA template, and the intracellular products formed early during infection and cell transformation.

We have investigated three aspects of RNA turmor virus replication and cell transformation: (1) the properties of the purified avian and mammalian viral RNA-directed DNA polumerase, (2) some characteristics of the viral 60-70S RNA genome, 30-40S RNA subunits and intracellular viral RNA species, and (3) the interaction of the viral DNA polymerase with its RNA template early during infection and cell transformation by the murine sarcoma-leukemia virus (MSV[MLV]). Avian myeloblastosis virus (AMV) contains two forms of RNA-directed DNA polymerase, alpha, consisting of a single polypeptide of molecular weight 65,000, and alphabeta, consisting of two polypeptides of molecular weights 65,000 and 105,000. The alpha and alphabeta forms of AMV DNA polymerase both possess RNase H activity that requires free end termini on the ribopolymer and can degrade the RNA of the RNA-DNA hybrid in the 3' to 5' and 5' to 3' directions. But, alpha and alphabeta possess a different mode of exoribonuclease activity. While alphabeta RNase H is a processive exoribonuclease that degrades the polynucleotide chain to a core residue before attacking a second chain, alpha RNase H is a random exoribonuclease that releases the polynucleotide after each scission. Highly purified Moloney-MSV(MLV) DNA polymerase has both RNase H activity and the ability to read viral 60-70S RNA. These activities comigrate through five different steps of purification and are present at levels comparable to those found in purified AMV DNA polymerase. The MSV(MLV) 60-70S RNA genome and 35S RNA subunits were shown by periodate oxidationtritiated borohydride reduction to contain adenosine as the major 3'-terminal nucleoside. Poly (A) segments were isolated from viral 60-70S and 35S RNA by treatment with RNase A or RNase T1 and purified by afinity chromatography and gel electrophoresis. Viral poly(A) was shown to be present at the 3' terminus as -G(C,U)A190AOH. The similar sequence reported for poly(A) present in mammalian mRNA suggests that similar mechanisma are involved in the transcription and processing of both cellular and viral DNA sequences. Within transformed cells replicating MSV(MLV), viral 35S and 20S RNA were found in membrane-bound polyribosomes, whereas only 35S RNA was detected in free polyribosomes. The origin and function of 20S RNA is unknown. The early events during rapid infection and cell transformation of mouse 3T6 cells by the Harvey strain of MSV(MLV) were studied. By both autoradiographic analysis and molecular hybridization, viral DNA synthesis was detected in the cytoplasm by 1 hour after infection, reached a maximum at 2 hours, and subsequently decreased. Cytological chase experiments produced evidence that cytoplasmic viral DNA was transported to the nucleus. In situ hybridization experiments using radioactive viral DNA product as a probe demonstrated the rapid association of viral DNA sequences with the chromocenters of interphase nuclei and with the centromeric heterochromatin regions of some chromosomes.

Avian Myeloblastosis Virus