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Biomedical subjects

J Grinsted

Publications and source records attributed to J Grinsted.

At least 19 recordsLinked to original sources
PubMed1992

Differential in vitro inhibition of feline enteric coronavirus and feline infectious peritonitis virus by actinomycin D.

The growth of feline enteric coronavirus strain 79-1683 in whole feline embryo cells was inhibited by the presence of 1 microgram/ml of actinomycin D in the culture fluid. No virus-specific mRNAs could be detected in such cultures and yields of infectious virus were depressed by > 99%. By contrast, the antigenically related feline infectious peritonitis virus strain 79-1146 was unaffected by the presence of actinomycin D, indicating a fundamental difference between the two feline coronavirus strains in their requirements for host-encoded function(s).

Animals↗
PubMed1992

Effects of lidocaine aerosol on postoperative pain and wound tenderness following minor gynaecological laparotomy.

Twenty-four female patients undergoing sterilization through a minor lower laparotomy received, in a double-blind, randomized study, either lidocaine spray 200 mg or placebo in the surgical wound. Postoperative pain intensity was evaluated on a verbal and a visual analogue scale and wound tenderness with an algometer. During mobilisation from the supine to the sitting position, VAS-score was lower (P less than 0.05) in the lidocaine group 2 h postoperatively, but not 4, 6 and 8 h postoperatively (P greater than 0.05). No significant differences were found in VAS-scores at rest or during cough, or in verbal scale ratings during rest, cough or mobilisation, and postoperative consumption of morphine was similar in the two groups. Pressure pain thresholds were higher (P less than 0.05) 2 h postoperatively in the lidocaine group, but not 4, 6 and 8 h postoperatively. In conclusion, topically applied lidocaine aerosol in the surgical wound leads to very short and clinically insignificant relief of postoperative pain.

Aerosols↗
PubMed1990

The Tn21 subgroup of bacterial transposable elements.

The Tn3 family of transposable elements is probably the most successful group of mobile DNA elements in bacteria: there are many different but related members and they are widely distributed in gram-negative and gram-positive bacteria. The Tn21 subgroup of the Tn3 family contains closely related elements that provide most of the currently known variation in Tn3-like elements in gram-negative bacteria and that are largely responsible for the problem of multiple resistance to antibiotics in these organisms. This paper reviews the structure, the mechanism of transposition, the mode of acquisition of accessory genes, and the evolution of these elements.

Bacteria↗
PubMed1990

Temperature sensitivity of transposition of class II transposons.

It has been reported that transposition of Tn3 is temperature-sensitive. The effect of temperature on the transposition of other class II bacterial transposable elements is reported here: Tn21, Tn501, Tn1721, Tn2501 and Tn3926 all also display temperature-sensitivity of transposition. The temperature at which the highest transposition frequency was observed varied between room temperature and 30 degrees C.

DNA Transposable Elements↗
PubMed1989

Prediction of ovulation.

The purpose of this investigation was to evaluate all available ovulatory diagnostics with respect to sensitivity, specificity, diagnostic specificity (predictive value of a positive test, PVP) and diagnostic sensitivity (predictive value of a negative test, PVN). Twenty-one ovulatory women with more than 3 years of infertility problems were included in the study. PVP and PVN were highest for detection of urinary luteinizing hormone (LH) peak at ovulation (PVP = 90%, PVN = 95%) and for serum-estradiol peak 1 day before ovulation (PVP = 83%, PVN = 97%). The predictive values were lower for all other tests. The PVP (54%) and PVN (90%) were rather low for detection of ovulation with vaginal electric impedance. However, all ovulations were predicted when urinary LH peak and vaginal impedance were combined. Two women were stimulated with human chorionic gonadotropin to investigate a possible connection between the LH peak and the preovulatory vaginal electric impedance. No close connection between them could be demonstrated. Basal body temperature should not be used for the prediction of ovulation (PVP = 25%). We suggest that ovulation should primarily be predicted from the identification of the urinary LH peak and that other methods be supplementary.

Analysis of Variance↗
PubMed1989

Effects of variation of inverted-repeat sequences on reactions mediated by the transposase of Tn21.

The frequencies of one-ended transposition and normal transposition of derivatives of Tn21 that contain mutant inverted-repeat sequences (IRs) have been measured. In general, there was a linear relationship between the log of the frequency of one-ended transposition of a mutant IR and the log of the frequency of normal transposition of an element flanked by a wild-type IR at one end and by the mutant IR at the other. This implied that one-ended and normal transposition share the rate-limiting step that determines the frequency of transposition and that both IRs are involved in the rate-limiting step in normal transposition. Surprisingly, it was found that only the outer 18 base pairs of the IR of Tn21 engaged accurately in both one-ended and normal transposition, at about 1% of the frequency of the wild-type IR.

Base Sequence↗
PubMed1989

"Stat" measurements of L-lactate in whole blood and cerebrospinal fluid assessed.

A first-generation semi-automatic amperometric lactate analyzer (Yellow Springs Instrument Co.) was assessed for urgent ("stat"), rapid laboratory measurements in whole blood and cerebrospinal fluid. For whole blood, measured lactate concentration and hematocrit were linearly correlated. An improved equation is presented for estimating the concentration of lactate in plasma from measurements in whole blood. The 95% reference range for the concentration of lactate in paired samples of capillary and venous whole blood from 40 healthy laboratory adults was found to be 0.4-1.5 mmol/L and 0.3-1.5 mmol/L, respectively. The 95% ranges for lactate in whole blood from 24 uncomplicated vaginal deliveries at term were established for cord venous blood, 1.2-5.0 mmol/L; cord arterial blood, 1.6-5.5 mmol/L; and maternal venous blood, 1.7-6.6 mmol/L. The 95% paired ranges were established for 20 lumbar-anaesthetized urological patients without neurological disorders after induction of anaesthesia for venous whole blood and cerebrospinal fluid (venous blood, 0.5-1.3 mmol/L; cerebrospinal fluid, 1.1-2.4 mmol/L).

Adult↗
PubMed1988

Factors that affect transposition mediated by the Tn21 transposase.

The frequencies of one-ended transposition mediated by the Tn21 transposase acting on plasmids containing 38-bp inverted repeat sequences (IRs) of both Tn21 and of Tn501/Tn1721 and Tn2501 were measured. The enzyme acted on all these IRs, but more efficiently on the homologous sequences. These differences were magnified when the enzyme acted on plasmids containing two copies of the IRs, inverted with respect to each other. The Tn21 enzyme did not recognize the IR of Tn3. The Tn501 transposase did not mediate measurable one-ended transposition of any of the plasmids used, including those containing an IR of Tn501.

DNA Transposable Elements↗
PubMed1988

Analysis of the variable endpoints generated by one-ended transposition of Tn21.

One-ended transposition of Tn21 generates recombinants usually containing a whole copy of the donor replicon plus a short duplication of it (S. Mötsch, R. Schmitt, P. Avila, F. de la Crue, E. Ward, and J. Grinsted, Nucleic Acids Res. 13:3335-3342, 1985). This work shows that recombinants containing less than a whole copy of the donor replicon (hereafter called short recombinants) could also be detected when plasmid donors which contained two selectable genetic markers were used. Short recombinants were produced at the same frequency from TnpR+ donor molecules as from TnpR- donor molecules in a RecA- background. Therefore, they were not resolution products of larger recombinants. This result invalidates a previous hypothesis to explain one-ended transposition, that is, that one-ended transposition arises from the use of secondary ends by the transposition apparatus. On the other hand, it suggests that one-ended transposition of Tn21 occurs via a simple insertion mechanism.

Base Sequence↗
PubMed1988

Gas-chromatographic measurement of carboxyhemoglobin in blood from mothers and newborns.

HbCO in blood sampled from 20 mothers and newborns immediately after birth was measured with a new, simple gas-chromatographic method for CO. The mean ratio of HbCO to total hemoglobin for 13 non-smoking mothers did not differ significantly from that for their infants (mean 0.38%, SD 0.26% vs 0.38%, SD 0.13%), but the HbCO ratio varied more in the mothers than in the infants (P less than 0.05). The infants of seven cigarette-smoking mothers, tobacco-abstinent for 7 h during labor, had higher HbCO ratios than their mothers (mean 1.88% vs 1.28%, P less than 0.05). The results are in harmony with the concept of equal affinities of fetal and adult hemoglobin for CO and a long time for passage of CO across the placenta.

Carboxyhemoglobin↗
PubMed1987

The nucleotide sequence of the tnpA gene of Tn21.

The nucleotide sequence of the tnpA gene of Tn21 is presented. The transposase encoded by this gene is exactly the same length (988 amino acids) as the Tn501 transposase (4), and shows 72% homology overall with this protein, with greater homology towards the C-terminus. The sequence of the transposase is discussed in the context of the evolution of Class II transposable elements and of the characteristics of the enzyme's action.

Amino Acid Sequence↗
PubMed1987

Tn2501, a component of the lactose transposon Tn951, is an example of a new category of class II transposable elements.

Tn2501 is a cryptic class II transposon found as part of the lactose transposon Tn951. Insertional inactivation and nucleotide sequence analysis of Tn2501 allowed us (i) to localize the transposase (tnpA) and the resolvase (tnpR) genes as well as the resolution site (res) of Tn2501 and (ii) to compare Tn2501 with other well-known elements of the two subgroups of class II transposons (Tn3, gamma delta, Tn951, IS101; and Tn21, Tn501, Tn1721). The genetic organization of Tn2501 is similar to that of Tn3 with divergent transcription of the tnpA and tnpR genes away from the intervening res site. The tnpR gene of Tn2501 shows weak homology with that of Tn3 and even less with those of Tn21 and Tn501. However, the tnpA gene and the inverted repeat sequences of Tn2501 present more homology with those of Tn21 and Tn501 than with those of Tn3. Complementation studies showed that TnpA- mutants of Tn2501 can be complemented, at a low frequency, by the Tn21 transposase. None of the tested transposons complemented TnpR- mutants of Tn2501.

Amino Acid Sequence↗
PubMed1987

Effects of induced abortion on the third stage of labor in subsequent pregnancy.

The aim of the study was to investigate whether the expulsion of the placenta was delayed among women who had previously undergone induced abortion by suction curettage. We studied the duration of the third stage of labor retrospectively by comparing the third stage of labor, recorded in minutes, between 76 second gravida women with previously induced abortions and 95 second para women with previously uncomplicated pregnancies. The duration of the third stage of labor was also compared among a group of primigravidas and a group of second gravidas with previously induced abortions. We excluded women with previous gynecological disorders (e.g. resulting in curettage of the uterine cavity). All patients included presented normal pregnancies and deliveries resulting in full term (greater than 37 weeks), liveborn infants. By the statistical analysis (analysis of variance and Duncan's test), it could be shown that the 3rd stage of labor lasted significantly longer among women with previously induced abortions (mean: 12 minutes), than among the other groups included in the study (mean: 9 minutes). This discrete difference in length of the third stage of labor need not indicate an altered routine for women, who give birth subsequent to an induced abortion.

Abortion, Induced↗
PubMed1986

Ultrastructure of germ cells and adjacent somatic cells correlated to initiation of meiosis in the fetal pig.

The ultrastructure of female and male germ cells and associated somatic cells were studied in morphologically sex differentiated fetal pig gonads from day 27 to day 95 post insemination. Before meiosis starts in the ovary, the organelles of germ cells and somatic cells of both sexes are poorly developed. In oocytes in leptotene stage, the endoplasmic reticulum attains close proximity to the plasma membrane forming characteristic contact areas which in addition are only seen in male germ cells of the same age. As meiosis progresses, the organelles of the oocyte increase in number and degree of differentiation. In particular the ER is prominent in the diplotene stage. At midgestation the male germ cells become polarized, the organelles gathering at one side of the nucleus. In the granulosa cells the number and extension of organelles increase concomitantly with the oocytes proceeding through meiosis. The Sertoli cells grow progressively complex in shape, with numerous mitochondria and a prominent ER, whereas the Golgi complex remains poorly developed. Small dense bodies are present both in germ cells and somatic cells. They are electron dense, membrane bounded, rounded or elongated granules often connected with endoplasmic reticulum. No activity of peroxidase, catalase or acid phosphatase could be traced in the granules, making them improbable candidates as peroxisomes or lysosomes. Their number is high in all germ cells and somatic cells on day 27 post insemination and in germ cells in leptotene stage.

Animals↗
PubMed1986

Evolution of transposable elements.

Transposable elements are at an advantage compared with other DNA sequences. This has led to the generation of transposable systems from a variety of different sources. Once fabricated, these elements can very simply acquire accessory genes, such as those that encode resistance to antibiotics. This can lead to further evolutionary advantages and to their shorter-term importance. It is likely that many new transposable systems will be discovered, owing to the advantages conferred on sequences by transposition, and it is certain that many new transposons that encode varying drug resistance patterns will arise.

Biological Evolution↗
PubMed1985

Junction sequences generated by 'one-ended transposition'.

In the presence of the cognate transposase, plasmids containing a single inverted repeat (IR) sequence of Tn21 or of Tn1721 can fuse efficiently with other plasmids ('one-ended transposition'). The junctions across the sequences of donor and recipient DNA in recombinants generated by this process have been determined. These show that the segment of donor DNA starts precisely at the IR sequence (it is variable at the other end), and is flanked by a direct repeat of host DNA (usually 5bp) that was present only once in the original host sequence. These are characteristics of recombinants generated by transposition of Tn21 and Tn1721 themselves, suggesting that the mechanism of one-ended transposition is very similar to that of the corresponding entire elements.

Base Sequence↗