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Biomedical subjects

I Constant

Publications and source records attributed to I Constant.

8 recordsLinked to original sources
PubMed1997

Video-assisted thoracoscopic surgery for right middle lobectomy in children.

This case-control study was designed to evaluate the potential advantages and disadvantages of video-assisted thoracoscopic surgery for right middle lobectomy in children. Ten children (6.1 +/- 3.0 yr, mean +/- SD) who underwent right middle lobectomy under videoscopy were compared with 10 controls matched for age (6.8 +/- 3.5 yr) and operated by thoracotomy (muscle-sparing technique) during the same period by the same surgeon. Operating time was significantly longer in the videoscopy group than in the thoracotomy group (146 +/- 28 mn vs 100 +/- 27 mn, P < 0.001). Minimum oxygen saturation values were significantly higher in the videoscopy group whereas oxygen requirements did not differ between groups. Incidence of postoperative respiratory complications (mainly atelectasis) was similar in the two groups. No difference in postoperative analgesic requirements in the postoperative period was demonstrated. No real benefit or disadvantage of videoscopy over standard thoracotomy could be observed in this retrospective case-control study.

Anesthesia, General↗
PubMed1996

The caudal-related homeodomain protein Cdx-2/3 regulates glucagon gene expression in islet cells.

Glucagon gene transcription in the endocrine pancreas is regulated by at least four cis-acting DNA control elements. We showed previously that G1 is critical for alpha cell-specific expression. G1 contains three AT-rich sequences important for promoter function, which represent candidate binding sites for homeodomain transcription factors. Performing reverse transcription-polymerase chain reaction amplifications with degenerate oligonucleotide primers homologous to the Antennapedia homeobox, cDNA clones corresponding to the caudal-related gene cdx-2/3 were predominantly obtained from glucagon-producing cells and primary non-beta cells. From RNase protection and polymerase chain reaction analyses, cdx-2/3 turned out to be the only caudal-related gene that is expressed at significant levels in cells of the endocrine pancreas. Cdx-2/3 binds with high affinity to an AT-rich motif of G1, which matches the consensus binding site of caudal-related proteins. In the glucagon-producing hamster cell line InR1G9, Cdx-2/3 is a subunit of complex B3 formed on G1. Alternative splicing generates two cdx-2/3 transcripts in islet cells, coding for a full-length protein and an amino-terminally truncated isoform. Although both isoforms bind G1 with similar affinity, only the full-length Cdx-2/3 A protein activates glucagon gene transcription in non-glucagon-producing cells, transcriptional activation being dose-dependent. We therefore conclude that the caudal-related gene cdx-2/3 is implicated in the transcriptional control of glucagon gene expression in the alpha cells of the islets of Langerhans.

Alternative Splicing↗
PubMed1996

Validity in nulliparas of increased beta-human chorionic gonadotrophin at mid-term for predicting pregnancy-induced hypertension complicated with proteinuria and intrauterine growth retardation.

The objective of the present study was to investigate whether increased beta-human chorionic gonadotrophin (beta HCG) plasma concentrations in an unselected population of nulliparas could predict the occurrence of complicated pregnancy-induced hypertension (PIH). The design was that of a prospective population study. It was conducted at the obstetric departments of Amiens University Hospital and Creil General Hospital on 434 consecutive nulliparas with singleton pregnancies after natural fertilization who accepted the systematic offer of trisomy 21 screening but for whom this disorder was finally estimated. Measurement of plasma concentration of beta HCG (ELISA method) was carried out between 14 and 20 weeks (mean: 17 weeks) of amenorrhea, and measurement of blood pressure and proteinuria (> 300 mg/24 h or Albustix +2) during the first, second and third term and 2-3 months after the delivery, as well as measurement of birth weight for determination of small for gestational age (SGA) babies, 37 women developed PIH, 10 without other complication, 16 with proteinuria (5 of which with SGA babies) and 11 with SGA babies. Furthermore 2 patients presented abruptio placentae without PIH. 395 women did not develop PIH including 389 normotensive women and 6 chronic hypertensive patients without superimposed toxemia. Only 1 was diabetic. None had chronic renal disease. Mean (+/- SD) levels of beta HCG were higher in PIH than in controls: 46,805 +/- 19,068 versus 23,479 +/- 13,463 IU. A pathologic threshold was chosen as the mean for the whole population + 1 SD: 25,613 + 15,479 = 41,082 IU. Elevated levels (above this value) were significantly associated with isolated PIH or PIH complicated with proteinuria and/or with SGA babies. The positive predictive value of this criterion was respectively 11, 15 and 12% for each of these complications. The relative risk (and 95% confidence limit) of women with elevated beta HCG for each of these complications was 20 (6-79), 11 (4-43) and 22 (7-93). Elevated plasma beta HCG found around 17 weeks of amenorrhea predicts PIH complicated with either proteinuria or SGA babies with a positive predictive value comparable to that of the best and earliest test proposed up to now to select nulliparas at high risk of preeclampsia, namely the abnormalities of the Doppler waveforms of the uterine arteries. Since this test is simpler to perform, it represents the most convenient method to screen a population of nulliparas for evaluation of the benefits of low-dose aspirin.

Adult↗
PubMed1995

Spectral analysis of systolic blood pressure and heart rate after heart transplantation in children.

1. The aim of the study was to examine the short-term variability in blood pressure and heart rate in 19 children who had received heart transplants and in eight normal control children. 2. Blood pressure was determined by a finger arterial pressure device. We examined the power spectra for heart rate and systolic blood pressure in the supine and tilted positions. In addition, we studied the acute changes in blood pressure and heart rate during active standing. 3. In the transplanted children we could distinguish two groups (groups A and B) in whom heart rate variability differed, although in both it was greatly reduced compared with controls (group C). In group A there were no significant fluctuations in the mid-frequency range for heart rate. The gain of the relationship between systolic blood pressure and heart rate was very low and there were virtually no heart rate changes associated with passive tilting. 4. By contrast, in group B transplant patients the heart rate variability, as assessed by standard deviation, was about half that of normal controls. The power spectra attenuation was greater in the high-frequency than in the mid-frequency bands. On passive tilting the latter became enhanced, but not the high-frequency variability. On active standing the tachycardic response was about half that of controls. The findings suggest some reinnervation involving cardiac sympathetic fibres to a greater degree than the fast-responding vagal fibres. 5. In both groups A and B the drop in systolic blood pressure observed early in active standing was about 4-6 times as great as in controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1995

[Latex hypersensitivity: a foreseeable accident?].

This paper describes another case of severe anaphylactic reaction due to allergy to natural rubber during anaesthesia in a child without known risk factors. The day after surgery the child reported that he experienced a few months ago an impressive skin reaction of both face and lips after inflating a latex balloon. It is suggested to try to detect latex allergy during the preoperative visit in all patients by including questions about latex sensitivity such as previous skin reactions or respiratory symptoms after wearing latex gloves or after inflating toy balloons. Patients in whom latex sensitivity is suspected should be tested appropriately in order to perform the planned surgery in a latex-free environment.

Adolescent↗
PubMed1995

[Spectrum analysis of heart rate and arterial systolic pressure after heart transplantation in children].

The aim was to examine the short-term variability of blood pressure (BP) and heart rate (HR) in 19 children who had received heart transplants and in 8 normal control children. BP was determined by a finger arterial pressure device. We examined the power spectra for HR and systolic blood pressure (SBP) in the supine and standing posture. In the transplanted children we could distinguish two groups (groups A and B) in whom HR variability differed, though in both it was greatly reduced compared to controls (group C). In group A there were no significant fluctuations in the mid frequency (MF) range for HF. Gain of the relationship between SBP and HR was very low and there were virtually no HR changes associated with passive tilting. By contrast, in group B transplant patients the HR variability, as assessed by standard deviation was about half that of normal controls. The power spectra attenuation was greater in the high frequency (HF) than in the MF bands. On standing the latter became enhanced, but not the HF variability. The findings suggest some reinnervation involving cardiac sympathetic fibres to a greater degree than the fast-responding vagal fibres. Time since operation was a critical factor for reinnervation since all subjects from group B were transplanted more than 44 months prior to the recording. We conclude that in a proportion of children who have received heart transplantation there is a delayed reinnervation of the heart, which probably involves sympathetic effectors rather than the vagus.

Age Factors↗
PubMedDate not supplied

Evaluation of the efficacy of a forced-air warmer (Bair Hugger) during spinal surgery in children.

STUDY OBJECTIVE: To evaluate the efficacy of a forced-air warmer during spinal surgery for correction of scoliosis in children. DESIGN: Prospective randomized study (group allocation based on the availability of the warming device). SETTING: Children's teaching hospital. PATIENTS: 51 ASA physical status I and II children (mean age, 15 years; mean weight, 45 kg) scheduled for posterior spinal fusion with general anesthesia. INTERVENTIONS: Study group (warmed; n = 26)--legs covered with the forced-air warmer (Bair Hugger, Augustine Medical, Inc., Eden Prairie, MN) after installation of the patient in prone position--versus control group (n = 25)--400W heat lamp placed over the head during surgery as is usually done in our institution. MEASUREMENTS AND MAIN RESULTS: Rectal temperature was taken every 15 minutes during surgery and during the first 2 hours in the recovery room. Time required for the wake-up test, time to extubation, and blood loss also were noted. Temperature profiles were very different in the 2 groups. In the control group, rectal temperature decreased during the first 180 minutes to a minimum of 34.8 degrees C +/- 0.6 degrees C, followed by a slow rewarming phase. In the warmed group, the lowest temperature (35.6 degrees C +/- 0.5 degrees C) was recorded 45 minutes after placement of the forced-air warmer, followed by an effective warming phase. At the end of surgery, temperature was significantly higher in the warmed group than in the control group (36.5 degrees C +/- 0.8 degrees C vs. 35.4 degrees C +/- 0.9 degrees C). However, time required for the wake-up test, time to extubation, and blood loss did not differ between groups. CONCLUSION: The forced-air warmer (Bair Hugger) is effective during spinal surgery, although only about 20% of body surface area can be covered.

Adolescent↗