PubMed Health⌕ Search

Biomedical subjects

E Meir

Publications and source records attributed to E Meir.

17 recordsLinked to original sources
PubMed2000

The segment polarity network is a robust developmental module.

All insects possess homologous segments, but segment specification differs radically among insect orders. In Drosophila, maternal morphogens control the patterned activation of gap genes, which encode transcriptional regulators that shape the patterned expression of pair-rule genes. This patterning cascade takes place before cellularization. Pair-rule gene products subsequently 'imprint' segment polarity genes with reiterated patterns, thus defining the primordial segments. This mechanism must be greatly modified in insect groups in which many segments emerge only after cellularization. In beetles and parasitic wasps, for instance, pair-rule homologues are expressed in patterns consistent with roles during segmentation, but these patterns emerge within cellular fields. In contrast, although in locusts pair-rule homologues may not control segmentation, some segment polarity genes and their interactions are conserved. Perhaps segmentation is modular, with each module autonomously expressing a characteristic intrinsic behaviour in response to transient stimuli. If so, evolution could rearrange inputs to modules without changing their intrinsic behaviours. Here we suggest, using computer simulations, that the Drosophila segment polarity genes constitute such a module, and that this module is resistant to variations in the kinetic constants that govern its behaviour.

Animals↗
PubMed1999

Adjustable silicone gastric banding and band erosion: personal experience and hypotheses.

BACKGROUND: Adjustable silicone gastric banding (ASGB) has been advocated as a minimally invasive procedure that is completely reversible for the surgical treatment of morbid obesity. Band erosion (BE) is one of the possible complications of ASGB. The authors report their experience with BE and discuss its possible causes. METHODS: Between February 1993 and February 1998, the authors performed 122 ASGB: 51 open and 71 laparoscopic procedures. RESULTS: Two cases of BE occurred (1.6%). CONCLUSION: Band erosion is a possible complication of ASGB that is often not diagnosed immediately. Prevention is essential and consists primarily in correct placement of the band. There appears to be only one solution to BE: removal of the band. Placement of a new band after removal is possible; the minimum interval is not known.

Adult↗
PubMed1999

Perforation due to ileocaecal tuberculosis.

A 40-year-old male patient was admitted in the Intensive Care Unit with complicated pulmonary tuberculosis. After 4 days he developed an acute abdomen with free air as demonstrated on plain abdominal films. A laparotomy was performed and an ileal perforation was found, located just before the ileocaecal valve. A right hemicolectomy was carried out and the resected specimen was send for further patho-anatomical examination. Our suspicion of ileocaecal perforation due to tuberculosis was confirmed. Despite further extensive medical treatment, the patient died 15 days after admission to the hospital. At autopsy, the cause of death was confirmed as being due to fulminant pulmonary tuberculosis.

Abdomen, Acute↗
PubMed1994

Mutations in the helper component protease gene of zucchini yellow mosaic virus affect its ability to mediate aphid transmissibility.

The nucleotide sequence of the helper component protease (HC-Pro) genes of three zucchini yellow mosaic virus (ZYMV) strains has been compared with that of a helper-deficient strain of ZYMV-HC. The comparisons revealed three unique deduced amino acid differences. Two of these mutations were located in regions which are conserved in other potyviruses. The role of these mutations in aphid transmissibility was examined by exchanging DNA fragments of part of the deficient HC-Pro gene with the respective section within the gene of the infectious full-length clone of the aphid-transmissible ZYMV. The first exchange included two of the three mutations, the first coding for a change from Asp to Gly (in a non-conserved region) and the second coding for a change from Arg to Ile [within the Phe-Arg-Asp-Lys (FRNK) conserved box]. This exchange resulted in a reduced transmission (20.6% for the mutated virus compared with 57.4% in the normal ZYMV when acquired from plants and 37.2% compared with 83.1%, respectively, when acquired from membranes). The second exchange incorporated a single mutation [conferring a change from Thr to Ala within the Pro-Thr-Lys (PTK) conserved box]. This single mutation resulted in almost total loss of HC activity in aphid transmission both from plants and from membranes. The Lys residue in the conserved Lys-Ile-Thr-Cys (KITC) box, which is related to loss of HC activity in potato virus Y, tobacco vein mottling virus and in the Michigan strain of ZYMV, is unchanged in the helper-deficient ZYMV. It is therefore proposed that more than one site in HC-Pro may be functionally related to aphid transmissibility. The possible reasons for the role of these mutations in helper activity in aphid transmission of ZYMV are discussed.

Amino Acid Sequence↗
PubMed1987

Efficacy of 1 alpha hydroxyvitamin D3 in the prevention of bovine parturient paresis.

One hundred and seventeen Israeli-Friesian cows from herds with a milk fever incidence of more than 15 per cent were injected intramuscularly with either 350 micrograms 1 alpha hydroxyvitamin D3 (1 alpha OHD3) in propylene glycol or with the vehicle alone, close to calving. If parturition had not occurred within 72 hours a second injection was administered; parturition was induced two days after the second injection if necessary. There were 10 cases of milk fever among 57 control cows as opposed to two cases among the 60 animals treated with 1 alpha OHD3. In an attempt to prolong the effect of the drug, Israeli-Friesian cows were injected intramuscularly with 350 micrograms 1 alpha OHD3 in either 10 ml propylene glycol or arachis oil. 1 alpha OHD3 in arachis oil did not prolong the effect of the drug. 1 alpha OHD3 in propylene glycol increased plasma calcium concentrations more rapidly than when the drug was administered in oil. Additional cows of the same breed and age were injected intramuscularly with 350 micrograms 1 alpha OHD3 in propylene glycol. Five of the animals received a second dose four days, and five received a second dose five days after the first injection. Five animals served as uninjected controls. The plasma calcium levels of the injected cows were significantly higher (P less than 0.01) than those of the controls from the second until the 14th day after the first injection. Based on these results 451 Israeli-Friesian cows from herds with a milk fever incidence of more than 15 per cent were injected intramuscularly with 1 alpha OHD3 close to calving.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Amniotic fluid alpha-fetoprotein levels and fetal chromosomal abnormalities.

406 midtrimester amniotic fluid samples were examined for alpha-fetoprotein (AFP) levels and fetal karyotyping. 44 cases with Down syndrome, 12 with Klinefelter syndrome and 14 with other chromosomal abnormalities were diagnosed. The AFP levels were below the median value for the normal pregnancies in 38 of the 44 Down syndrome-affected fetuses. The mean AFP value was significantly lower (p less than 0.0001) in this group. No such difference was found for fetuses affected by Klinefelter syndrome or other chromosomal aberrations. Almost all of the values for the Down syndrome-affected fetuses were, however, within the normal range, thereby precluding the possibility of using this measurement as an alternative to fetal karyotyping as a screening test for Down syndrome.

Amniotic Fluid↗
PubMed1986

Effect of blood contamination on the fluorescence polarization value of amniotic fluid lamellar bodies.

Estimation of fetal lung maturity by examination of amniotic fluid samples is unreliable in the presence of blood. Centrifugation of amniotic fluid at 10,000 X g separates the surfactant-containing lamellar bodies from contaminants, such as serum lipids. The influence of serum contamination of amniotic fluid was evaluated using the fluorescence polarization technique for determination of fetal lung maturity. Addition of serum changed the amniotic fluid P value of both the amniotic fluid and the lamellar body pellets in the direction of the P value of serum. After centrifugation at 10,000 X g, there was no significant difference in the P value of the pre- and postcontamination samples, demonstrating that centrifugation resulted in the removal of pulmonary nonrelevant lipids in contaminated amniotic fluid specimens. In 24 patients in whom the amniotic fluid sample was blood stained, the P value on the lamellar body pellet compared favorably to that obtained from noncontaminated samples.

Amniotic Fluid↗
PubMed1986

Determination of fetal lung maturity by fluorescence polarization of the amniotic fluid lamellar bodies.

High-speed centrifugation of amniotic fluid enables separation of surfactant-containing lamellar bodies. Fifty-three amniotic fluid samples from pregnancies of 28 to 39 weeks' gestation were examined for fetal lung maturity by measuring fluorescence polarization (P). For each sample the P value was determined at 37C on both the whole amniotic fluid and on the surfactant-containing lamellar bodies obtained by centrifugation at 10,000 X g. A close linear correlation (r = 0.80) was found between the P value of the amniotic fluid samples and that of the lamellar bodies. There was no difference in the specificity for discrimination of hyaline membrane disease cases by both methods (93.5%) with 95% confidence limits of 82.1 to 98.6%. Because high-speed centrifugation enables the selective sedimentation of pulmonary surfactant, determination of the lamellar body P value may offer a practical solution for the estimation of fetal lung maturity in amniotic fluid samples contaminated with blood.

Amniotic Fluid↗
PubMed1975

Modification of the Rappaport rapid test in large-scale testing for syphilis. Evaluation of the rapid plate and rapid card tests.

The Rappaport rapid (RR) plate and card tests were developed as modifications of the RR tube test to permit rapid and inexpensive screening of large numbers of subjects for the diagnosis of syphilis. More than 2,000 sera were examined in parallel by the Venereal Disease Research Laboratory (VDRL) slide test, the rapid plasma reagin (RPR) card test and the RR plate and card tests. There was complete agreement between the RR plate and card tests and the VDRL slide and RPR card tests in 96.6% of sera. In a selected group of 1,530 sera examined, in addition, by the fluorescent treponemal antibody absorption (FTA-ABS) test, there was agreement between the RR plate and card tests and the FTA-ABS test in 74.3% of sera and between the VDRL and RPR tests and the FTA-ABS test in 73.7% of sera. The RR plate test was found to be sufficiently sensitive and specific for the diagnosis of syphilis, although the VDRL slide test is perhaps more sensitive in primary and late latent syphilis. Since the antigen used in the RR tests is colored and stable and the sera do not require inactivation before the test, the tests are easier to perform than the VDRL slide test: the RR plate and card tests could therefore replace the VDRL test as a screening test, with hardly any loss of accuracy.

Flocculation↗
PubMedDate not supplied

Laparoscopic transperitoneal mesh repair of inguinal hernia. A preliminary review of 120 cases.

From april 1992 to april 1994 we performed 120 laparoscopic transperitoneal hernia repairs using a polypropylene mesh. This paper is a preliminary review of the method we used and our results. We operated upon 105 patients including 40 direct, 79 indirect and 1 femoral hernias. The inguinal region is approached transperitoneally through 3 trocars placed in the lower abdominal region. A dissection of the pre-peritoneal inguinal space is performed and a 14 x 8 cm mesh is fixed using a stapling device. We have had some peroperative complications (injury to the epigastric vessels and the vas deferens, bowel injury), mainly in our early experience with this new technique. Postoperative complications consisted of minor problems (scrotal seroma and induration of the spermatic cord) 3 infections, 1 patient with prolonged pain and 1 recurrence. Some of these problems can be resolved by adjusting the technique. There seems to be less postoperative pain and a shorter convalescence period allowing active persons to return to work earlier than with classic herniorrhaphy. Since this is a new technique, no definite conclusions can be drawn at the moment.

Adult↗