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Biomedical subjects

D Jacob

Publications and source records attributed to D Jacob.

At least 37 records · Page 2Linked to original sources
PubMed2002

Assessment of reversible contraceptive efficacy of methanol extract of Mentha arvensis L. leaves in male albino mice.

The present study was undertaken to assess the reversible contraceptive efficacy of methanolic extract of Mentha arvensis leaves. Aqueous solution of the extract (10 mg per day per mouse) when administered orally to male mice of proven fertility for 20, 40 and 60 days caused inhibition of fertility while maintaining their normal sexual behaviour. With the increase in treatment duration, there occurred a corresponding decrease in the mean weight of testis and accessory organs of reproduction. Sperm concentration, motility and viability in the cauda epididymis were also decreased. Spermatozoa with coiled tails also appeared in the epididymal smear. However, all the induced effects returned to normalcy within 30 days following withdrawal of 60-day treatment. Oral administration of the extract also did not affect the body weight of the mice and their blood cells count, packed cell volume, haemoglobin and blood/serum biochemistry.

Administration, Oral↗
PubMed2001

Evidence from the Pacific troposphere for large global sources of oxygenated organic compounds.

The presence of oxygenated organic compounds in the troposphere strongly influences key atmospheric processes. Such oxygenated species are, for example, carriers of reactive nitrogen and are easily photolysed, producing free radicals-and so influence the oxidizing capacity and the ozone-forming potential of the atmosphere-and may also contribute significantly to the organic component of aerosols. But knowledge of the distribution and sources of oxygenated organic compounds, especially in the Southern Hemisphere, is limited. Here we characterize the tropospheric composition of oxygenated organic species, using data from a recent airborne survey conducted over the tropical Pacific Ocean (30 degrees N to 30 degrees S). Measurements of a dozen oxygenated chemicals (carbonyls, alcohols, organic nitrates, organic pernitrates and peroxides), along with several C2-C8 hydrocarbons, reveal that abundances of oxygenated species are extremely high, and collectively, oxygenated species are nearly five times more abundant than non-methane hydrocarbons in the Southern Hemisphere. Current atmospheric models are unable to correctly simulate these findings, suggesting that large, diffuse, and hitherto-unknown sources of oxygenated organic compounds must therefore exist. Although the origin of these sources is still unclear, we suggest that oxygenated species could be formed via the oxidation of hydrocarbons in the atmosphere, the photochemical degradation of organic matter in the oceans, and direct emissions from terrestrial vegetation.

Journal Article↗
PubMed2001

LACBED measurement of the chemical composition of a thin In(x)Ga(1-x)As layer buried in a GaAs matrix.

Large angle convergent beam electron diffraction (LACBED) observations are used to determine the x indium content of a thin In(x)Ga(1-x)As quantum well buried in a GaAs matrix. The method consists in a quantitative analysis of the Bragg line intensities lying in the central disc of any LACBED pattern. This analysis makes it possible to determine the displacement vector R introduced, between the two parts of the GaAs matrix, by the deformation of the quantum well and consequently to determine the x indium content. This indium content is found to be consistent with the value expected from the molecular beam epitaxy growth conditions.

Journal Article↗
PubMed2001

[Maternal weight gain during pregnancy in various immigrant communities living in France].

BACKGROUND: The aim of this study was to estimate, by geographic origin, the average situation of pregnant women who recently immigrated into the Paris area, using weight gain during pregnancy and infant birth weight. METHODS: The clinical files of 559 pregnant women who attended the antenatal clinic at the Lariboisière Hospital (Paris) in 1997 and gave birth in this same hospital were analyzed. The mothers had immigrated from North Africa, Sub-Saharan Africa, Sri Lanka, China and metropolitan France. The successive body mass indexes were calculated for each woman, as well as the increase of this index during the first semester of gestation, until the third trimester and during the entire gestation. Averages in studied communities were compared with those of the non-immigrant population attending the same hospital department. The birth weights of infants from the different communities were compared with those of children born to non-immigrant mothers. RESULTS: Women from the various communities studied (with the exception of the Turkish community) showed a lower gestation weight gain than non-immigrant French women. Independently of the pregestational weight, weight gain during pregnancy accounted for 20% of the initial weight among women from North Africa, Turkey and China who gave birth to children whose birth weight was not significantly different from that of the non-immigrant French children. The mean weight gain corresponded to 15.8% of the pregestation weight in Sub-Saharan women and 18% in Sri Lanka women. Birth weights of children in these two communities were significantly lower than the French reference population. Compared with the weights observed in their original country, the frequency of low birth weight was lower and the mean birth weight was higher. CONCLUSION: Women coming from North Africa, Sub-Saharan Africa, and Asia who recently immigrated into France gave birth to children of satisfactory birthweight. The number of low birth weights decreased to the frequencies observed in their original countries. Irrespective for their reasons for immigrating, immigrant families living in France have newborns with a sufficient birth weight to allow satisfactory growth.

Adolescent↗
PubMed2000

[Treatment of parathyroid adenomas with ethanol injection under ultrasonographic guidance].

STUDY OBJECTIVE: The objective of this retrospective study was to report the results of ethanol injection in parathyroid adenomas. PATIENTS AND METHOD: Since 1988, 31 patients with inoperable primary hyperthyroidism have been treated by ultrasound-guided percutaneous ethanol injection into the adenoma. The main surgical contraindications were heart failure (n = 12) and age over 85 years (n = 11). Plasma calcium and PTH were measured 48 hours after ethanol injection and during subsequent follow-up. RESULTS: Patients had one to three ethanol injections. With a mean 5-year follow-up, total success with normal plasma calcium and PTH levels was achieved in 20 patients (64.5%), 4 of whom underwent another ethanol injection after 1 to 3 years. Partial success with correction of plasma calcium only was achieved in 9 patients (29%) resulting in an obvious clinical benefit. Failure was observed in 2 patients (6.5%) with nodular goiter, probably due to incorrect localization of the adenoma. Treatment was always well tolerated and no major side effect was observed. CONCLUSION: Ultrasound-guided percutaneous ethanol injection of parathyroid adenoma is effective in most cases of hyperparathyroidism and very useful in patients with a high surgical risk. The need for precise ultrasound localization of the adenoma is the main limitation of this treatment.

Adenoma↗
PubMed2000

Six-month daily administration of parathyroid hormone and parathyroid hormone-related protein peptides to adult ovariectomized rats markedly enhances bone mass and biomechanical properties: a comparison of human parathyroid hormone 1-34, parathyroid hormone-related protein 1-36, and SDZ-parathyroid hormone 893.

Daily administration of parathyroid hormone (PTH) and PTH-related protein (PTHrP) peptides has been shown to increase bone mass and strength in animals and, for PTH, to increase bone mass in humans. Long-term direct comparison of multiple members of the PTH/PTHrP family in vivo has not been reported. We therefore selected three PTH/PTHrP molecules for direct comparison in vivo in an adult rat model of postmenopausal osteoporosis: PTH(1-34), PTHrP(1-36), and the PTH analog, SDZ-PTH 893 ¿Leu8, Asp10, Lys11, Ala16, Gln18, Thr33, Ala34 human PTH 1-34 [hPTH(1-34)]¿. A 6-month study was performed in which adult (6-month-old) vehicle-treated ovariectomized (OVX) and sham OVX rats were compared with OVX rats receiving 40 micrograms/kg per day of either PTH(1-34), PTHrP(1-36), or PTH-SDZ-893. Bone mass, as assessed by ash weight and densitometry, bone histomorphometry, biomechanical properties at trabecular and cortical sites, and indices of bone formation markedly increased in all three PTH/PTHrP peptide-treated groups as compared with controls. In general, this improvement followed a rank order of SDZ-PTH-893 > PTH > PTHrP. The adverse effect profile also was greatest with SDZ-PTH-893; these rats developed moderate hypercalcemia, marked renal calcium accumulation, and displayed a 13% mortality. These studies show that PTH(1-34), PTHrP(1-36), and PTH-SDZ-893 significantly and progressively increase bone mass and bone strength in this rat model of postmenopausal osteoporosis. The adverse effect profile correlates in general terms with efficacy. All three peptides show promise as skeletal anabolic agents. Further studies in humans will be required to define optimal efficacy-to-adverse effect ratios and relative efficacy for each peptide in human osteoporosis.

Animals↗
PubMed2000

[Uterine artery embolization: anatomical and technical considerations, indications, results, and complications].

The first reported use of transcatheter arterial embolization in the management of intractable bleeding related to pelvic trauma appeared in the literature in 1973. Other indications for pelvic embolization in women include postoperative and postpartum hemorrhage and bleeding related to gynecologic malignancy. Recently, the use of uterine artery embolization in the management of symptomatic leiomyoma has been reported as an alternative to surgery. The widespread acceptance of this procedure necessitates greater knowledge of the arterial anatomy of the female genital tract. In this paper, main arterial variations in uterine vascularization and procedure-relevant technical considerations will be discussed. Indications, results and potential complications of uterine artery embolization will be listed and explained.

Angiography↗
PubMed1999

Unique checkpoints during the first cell cycle of fertilization after intracytoplasmic sperm injection in rhesus monkeys.

Intracytoplasmic sperm injection has begun an era of considerable improvements in treating male infertility. Despite its success, questions remain about the dangers of transmitting traits responsible for male infertility, sex and autosomal chromosome aberrations and possible mental, physical and reproductive abnormalities. We report here the first births of rhesus monkeys produced by intracytoplasmic sperm injection at rates greater or equal to those reported by clinics. Essential assumptions about this process are flawed, as shown by results with the preclinical, nonhuman primate model and with clinically discarded specimens. Dynamic imaging demonstrated the variable position of the second meiotic spindle in relation to the first polar body; consequently, microinjection targeting is imprecise and potentially lethal. Intracytoplasmic sperm injection resulted in abnormal sperm decondensation, with the unusual retention of vesicle-associated membrane protein and the perinuclear theca, and the exclusion of the nuclear mitotic apparatus from the decondensing sperm nuclear apex. Male pronuclear remodeling in the injected oocytes was required before replication of either parental genome, indicating a unique G1-to-S transition checkpoint during zygotic interphase (the first cell cycle). These irregularities indicate that the intracytoplasmic sperm injection itself might lead to the observed increased chromosome anomalies.

Animals↗
PubMed1999

Secondary postpartum hemorrhage: treatment with selective arterial embolization.

PURPOSE: To evaluate the efficacy and safety of selective arterial embolization of the uterine arteries in the management of intractable delayed postpartum hemorrhage. MATERIALS AND METHODS: Fourteen consecutive women with secondary postpartum hemorrhage were treated with selective embolization of the uterine arteries. In all cases, hemostatic embolization was performed because of intractable hemorrhage that could not be controlled with the administration of uterotonic drugs or with uterine curettage. RESULTS: The causes of bleeding included genital tract tears in four women and endometritis in eight women; the endometritis was associated with proved, retained portions of placenta in four women. In two women, no evident cause of bleeding was found before angiography. Angiography revealed extravasation in three women. A false aneurysm of the uterine artery was found in two women. In one patient, an arteriovenous fistula was observed. Immediate resolution of external bleeding was observed in all women. No complication related to embolization was found. Normal menstruation resumed in all women. CONCLUSION: Selective arterial embolization of the uterine arteries is a safe and effective means of controlling secondary postpartum hemorrhage.

Adult↗