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Biomedical subjects

J C Jennings

Publications and source records attributed to J C Jennings.

At least 19 recordsLinked to original sources

Attempts to detect transgenic and endogenous plant DNA and transgenic protein in muscle from broilers fed YieldGard Corn Borer Corn.

Questions regarding the digestive fate of DNA and protein from transgenic grain have been raised in regard to human consumption and trade of animal products (e.g., meat, milk, and eggs) from farm animals fed transgenic crops. Using highly sensitive, fully characterized analytical methods, fragments of transgenic and endogenous plant DNA, as well as transgenic protein, were not detected in chicken breast muscle samples from animals fed YieldGard Corn Borer Corn event MON 810 (YG). Total DNA was extracted from breast muscle samples from chickens fed for 42 d with a diet including either 55 to 60% YG grain or 55 to 60% conventional corn grain. DNA preparations were analyzed by PCR followed by Southern blot hybridization for the presence of a 211-bp fragment of the Bacillus thuringiensis (Bt) cry1Ab gene and a 213-bp fragment of the endogenous corn gene sh2 (encoding ADP glucose pyrophosphorylase). By using 1 microg of input DNA per reaction, none of the extracted samples was positive for cry1Ab or sh2 at the limit of detection for these PCR assays. A 396-bp fragment of the chicken ovalbumin (ov) gene, used as a positive control, was amplified from all samples showing that the DNA preparations were amenable to PCR amplification. By using a competitive immunoassay with a limit of detection of approximately 60 ng of CrylAb protein per gram of chicken muscle, neither the CrylAb protein nor immunoreactive peptide fragments were detectable in the breast muscle homogenates from chickens fed YG grain.

Animal Feed↗

Determining whether transgenic and endogenous plant DNA and transgenic protein are detectable in muscle from swine fed Roundup Ready soybean meal.

Questions regarding the digestive fate of DNA and protein from transgenic feed have been raised in regard to human consumption and commercial trade of animal products (e.g., meat, milk, and eggs) from farm animals fed transgenic crops. Using highly sensitive, well-characterized analytical methods, pork loin samples were analyzed for the presence of fragments of transgenic and endogenous plant DNA and transgenic protein from animals fed meal prepared from conventional or glyphosate-tolerant Roundup Ready (RR) soybeans. Pigs were fed diets containing 24, 19, and 14% RR or conventional soybean meal during grower, early-finisher, and late-finisher phases of growth, respectively, and longissimus muscle samples were collected (12 per treatment) after slaughter. Total DNA was extracted from the samples and analyzed by PCR, followed by Southern blot hybridization for the presence of a 272-bp fragment of the cp4 epsps coding region (encoding the synthetic enzyme 5-enolpyruvylshikimate-3-phosphate synthase derived from Agrobacterium sp. strain CP4) and a 198-bp fragment of the endogenous soybean gene le1 (encoding soy lectin). Using 1 microgram of input DNA per reaction, none of the extracted samples was positive for cp4 epsps or le1 at the limit of detection (LOD) for these PCR/Southern blot assays. The LOD for these assays was shown to be approximately one diploid genome equivalent of RR soybean DNA, even in the presence of 10 micrograms of pork genomic DNA. A 185-bp fragment of the porcine preprolactin (prl) gene, used as a positive control, was amplified from all samples showing that the DNA preparations were amenable to PCR amplification. Using a competitive immunoassay with an LOD of approximately 94 ng of CP4 EPSPS protein/g of pork muscle, neither the CP4 EPSPS protein nor the immunoreactive peptide fragments were detected in loin muscle homogenates from pigs fed RR soybean meal. Taken together, these results show that neither small fragments of transgenic DNA nor immunoreactive fragments of transgenic protein are detectable in loin muscle samples from pigs fed a diet containing RR soybean meal.

Animal Feed↗

Osteoporosis in children and adolescent girls: case report of idiopathic juvenile osteoporosis and review of the literature.

UNLABELLED: The diagnosis and treatment of osteoporosis is an important aspect of gynecologic training and practice. Idiopathic juvenile osteoporosis (IJO) is a rare disease of children and adolescents that resolves after the onset of puberty. A case report is presented and current methods of diagnosis and treatment of IJO are discussed as well as the differential diagnosis. A MEDLINE search was performed of the following terms: idiopathic juvenile osteoporosis, pediatric osteoporosis, adolescent osteoporosis, bisphosphonates pediatric adolescent, and pregnancy osteoporosis, and references from bibliographies of selected papers were used as well. All papers in English, French, and German are considered in this review. There were 114 papers selected as relevant to the topic. Data relevant to the diagnosis, pathogenesis, methods of imaging, laboratory evaluation, differential diagnosis, and treatment of IJO are presented. IJO is a diagnosis of exclusion in the pediatric and adolescent patient with osteoporosis. Although bone density gradually improves after the onset of puberty, treatment of currently affected children and adolescents involves activity restriction, calcium, vitamin D, and bisphosphonate therapy. Future reproductive concerns are discussed and areas requiring additional study are reviewed. TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians LEARNING OBJECTIVES: After completion of this article, the reader will be able to describe the condition idiopathic juvenile osteoporosis, compare the clinical features of this condition to other similar conditions, outline the diagnostic workup of a child with this condition, and list the potential therapeutic options for a patient with idiopathic juvenile osteoporosis.

Adolescent↗

The 24-kDa protein from Fusarium oxysporum f.sp. erythroxyli: occurrence in related fungi and the effect of growth medium on its production.

A 24-kDa protein that elicits ethylene production and necrosis in leaves of dicotyledonous plants was previously purified from culture filtrates of Fusarium oxysporum Schlechtend:Fr. f.sp. erythroxyli. Antisera to the denatured 24-kDa protein detected 2.5 ng of the 24-kDa protein on Western blots at 100000-fold dilutions. The antisera cross-reacted with a 24-kDa protein on Western blots of culture filtrates from three other F. oxysporum formae speciales. Of seven Fusarium species, only F. oxysporum, F. acuminatum Ellis and Kellerm., and F. avenaceum (Fr.:Fr.) Sacc. isolates produced an antigenically related 24-kDa protein. Although there were differences in the profiles of proteins extracted from stems of coca (Erythroxylum coca var. coca L. Lam.) infected with F. oxysporum f.sp. erythroxyli compared with uninfected stems, antisera to the 24-kDa protein did not cross-react with any proteins from the infected coca stems. For the fungal isolates studied, the best medium tested for production of the 24-kDa protein contained 1% sucrose and 1% asparagine. Biological activity of the F. oxysporum culture filtrates on sweet basil leaves was consistently correlated with the presence of the 24-kDa protein. Production of the 24-kDa protein was limited in cultures containing pectin or cellulose as the primary carbon source, or in cultures lacking sucrose or casamino acids. Water-soluble extracts from coca stems inhibited production of the 24-kDa protein, whereas cellulose and pectin did not. Components produced by the plant may limit production of the 24-kDa protein in infected plant tissue and thereby limit the response of the plant to the fungus. These results suggest the 24-kDa protein does not function in the symptomatic phase of the F. oxysporum f.sp. erythroxylicoca disease interaction.

Culture Media↗

Subtractive hybridization between cDNAs from untreated and AMO-1618-treated cultures of Gibberella fujikuroi.

The gibberellin (GA) biosynthetic pathway includes four apparent cytochrome P450-mediated steps that convert kaurene to 7 alpha-hydroxykaurenoic acid. One of these reactions, the hydroxylation of kaurenoic acid to 7 alpha-hydroxykaurenoic acid, is mediated by kaurenoic acid hydroxylase. This reaction can be catalyzed in vitro by microsomal preparations from the fungus Gibberella fujikuroi (Saw.) Wr. and monitored by HPLC. Cultures grown in the presence of 84 microM AMO-1618 (an inhibitor of kaurene synthesis) had reduced levels of GA3 in fungal filtrates and decreased cell-free kaurenoic acid hydroxylase activity. However, the level of hydroxylase activity from AMO-1618-treated cultures could be induced several-fold by growing cultures in the presence of 350 microM kaurene. Since transcripts related to GA biosynthesis might be decreased in AMO-1618-treated cultures, a subtractive hybridization procedure was used to enrich cDNA fragments corresponding to messages that are more abundant in untreated than treated cultures. A fungal cDNA library was screened with the subtraction products and a clone was isolated that corresponds to two down-regulated transcripts in AMO-1618-treated cultures. This cDNA does not encode a cytochrome P450 but may be associated with GA biosynthesis.

Amino Acid Sequence↗

Reduced cell-cell communication in experimentally induced autoimmune thyroid disease.

We have recently described a spontaneous murine model of autoimmune thyroid disease. The disorder was in part characterized by reduced thyroid epithelial cell-cell communication that was associated with abnormalities in three major connexins. To compare whether this finding was a common secondary occurrence in autoimmune thyroid disease, or unique to the spontaneous development in the MRL mice, we induced thyroiditis in Lewis rats. Immunization with thyroid extract and thyroglobulin resulted in extensive lymphocytic infiltration and increased expression of major histocompatibility gene complex (MHC) class II surface antigen in the diseased thyroid. Both experimental and control rat thyroid tissues produced gap junction proteins connexin 43, connexin 32, and connexin 26. The connexins in nondiseased tissue was located in the plasma membrane at points of cell-cell contact and labeled as discrete arrays of punctate fluorescence. The quantity of all three connexins were reduced in the diseased thyroid tissue. More importantly, the connexin proteins were not distributed as gap junctions at contacting cell interfaces. Both nondiseased and diseased thyroid tissue expressed messenger RNA (mRNA) for the three connexins, but the diseased tissue had reduced levels of mRNA for connexin 43 (45%), and to a lesser extent, connexin 26 (25%) and connexin 32 (20%). The reduced connexin mRNA, protein, and lack of assembled gap junctions measured in the diseased tissue were obtained under conditions where the infiltrating cells and their potent cytokine products were continuously present. To determine if this difference persisted when these inflammatory components were absent, primary cultures of thyroid cells from control and experimental rats were established and connexin localization experiments repeated. The diseased thyroid cells, like the diseased tissue, lacked plasma membrane associated connexin protein. The lack of gap junction assembly in the thyrocytes cultured from the diseased tissue was accompanied by a loss of functional coupling. Collectively, the data document that autoimmune diseased thyroid tissue from both the spontaneous mouse and induced rat models have reduced plasma membrane assembled gap junctions and deficient intercellular communication as determined by the inability to transfer lucifer yellow dye to contiguous cells. Nondiseased cultured thyrocyte monolayers and follicles transferred dye to second and third order neighboring cells in 80 and 95% of trials, respectively. In contrast, only 5-10% of the diseased thyrocytes transferred microinjected dye, and in these cases the transit was limited to primary contacting cells. Culturing removed inequities introduced by the infiltrating cells and their products. However, the established cultures of diseased thyroid cells retained their communication deficiency. This suggests that the loss of communication may be a common abnormality in autoimmune disease, and furthermore, this uncoupling could contribute to the loss of coordinated hormonal regulation (hypothyroidism) in the diseased thyroid gland in the absence of thyroid cell destruction.

Animals↗

In vitro fertilisation. A review of drug therapy and clinical management.

Since the first in vitro fertilisation (IVF) pregnancy was delivered in 1978, this procedure has resulted in thousands of pregnancies and opened a vast new frontier of research and treatment for the infertile couple. Pregnancy rates with IVF improve as the number of high quality embryos available for transfer increases; therefore, ovarian stimulation agents to produce multiple oocysts for IVF are advantageous. Clomifene (clomiphene citrate), human menopausal gonadotrophin (hMG; menotropins), and subsequent generations of products are commonly used as stimulation agents. In conjunction with the stimulation agents, gonadotrophin-releasing hormone (GnRH) agonists and human chorionic gonadotrophin (hCG) serve as adjuvants for successful control of all events in the induction process. Clomifene, an estrogen agonists/antagonist, occupies the estrogen receptor for a longer period of time than estrogen (weeks versus hours). Because this signal is interpreted as low estrogen, GnRH is released, which produces a rise in circulating levels of follicle-stimulating hormone (FSH) and luteinising hormone (LH) and subsequent ovarian follicular development. Menotropins is collected by passing urine from menopausal donors over a Sepharose column, followed by removal of high molecular weight impurities by chromatography. The mixture of FSH and LH is biologically standardised. This product stimulates multiple ovarian follicular development. Urofollitrophin is produced using antibodies to hCG anchored to a separation column. LH then can be excluded from the eluate by binding to the hCG antibodies (LH immunoaffinity column). Highly purified FSH is obtained by passing menopausal urine over a column with monoclonal antibodies to FSH. The isolated FSH is then eluted from the column by a highly basic solution and crystallised. This product delivers FSH at a 90% purity and can be administered subcutaneously rather than intramuscularly. Dosage is standardised on a mg/kg basis. Recombinant human FSH is completely free of LH and offers the advantages of better batch consistency, greater purity, and absence of any human contaminants. It may be given both subcutaneously and intravenously. Genetically engineered FSH combines portions of the native protein with another protein (hCG) which enhances its potency and extends the half-life compared with wild-type FSH. Short, medium and ultra-long activity analogues of genetically engineered FSH may be used to tailor stimulation protocols in various clinical situations. Growth hormone is an adjuvant to ovarian stimulation which results in a decreased number of ampoules of menotropins being required to achieve ovulation in poor responders. Ovulation triggers include both hCG and GnRH agonists. Progesterone supplementation is generally used in the luteal phase of the IVF cycle and is administered by intramuscular injection or vaginal suppository. It appears that conscious sedation with midazolam, pethidine (meperidine) and fentanyl is nontoxic for oocyte recovery. If full anaesthesia is required for gamete intrafallopian tube transfer (GIFT) or zygote intrafallopian tube transfer (ZIFT), balanced anaesthesia with nitrous oxide and an opioid appears to be the most appealing option. Appropriate information on the clinical use of the drugs used in IVF greatly reduces patient stress associated with the complex multidrug regimens associated with the procedure.

Antibiotic Prophylaxis↗

Abnormal uterine bleeding.

Physicians who care for female patients cannot avoid the frequent complaint of abnormal uterine bleeding. Knowledge of the disorders that cause this problem can prevent serious consequences in many patients and improve the quality of life for many others. The availability of noninvasive and minimally invasive diagnostic studies and minimally invasive surgical treatment has revolutionized management of abnormal uterine bleeding. Similar to any other disorder, the extent to which a physician manages abnormal uterine bleeding depends on his or her own level of comfort. When limitations of either diagnostic or therapeutic capability are encountered, consultation and referral should be used to the best interest of patients.

Dilatation and Curettage↗

Presence of azithromycin breast milk concentrations: a case report.

We describe a case of breast milk concentrations of azithromycin, an azalide antibiotic, in a woman with postpartum bilateral tubal ligation incisional cellulitis. Azithromycin appears to demonstrate a time-dependent versus time-accumulation profile in breast milk.

Adult↗

Content of continuing education courses in obstetrics and gynecology.

The objective of this study was to determine the emphases of continuing medical education courses in obstetrics and gynecology. Eighty programs for obstetricians and gynecologists were evaluated for location, accreditation, sponsorship, cost, faculty composition, teaching methods, and curriculum content. The programs' curricula were compared through classification of courses and individual topic presentations as emphasizing primary care, maternal-fetal medicine, gynecologic oncology, reproductive endocrinology and infertility, introduction of new technology, or general review. All 80 programs were in acceptable locations and had valid accreditation. Universities, hospitals, industrial corporations, and professional organizations were among the programs' sponsors. Tuition costs per credit hour averaged $46.48 and ranged from $4.64-238.09; programs emphasizing new technology cost the most. Ninety percent of the programs' 880 faculty had medical school affiliations. Of the teaching methods, lectures accounted for 77.9%, laboratory instruction 9.1%, panel discussions 7.0%, workshops 4.9%, and other methods 1.0%. The total 1592 credit hours consisted of 563 in primary care, 181 in maternal-fetal medicine, 99.5 in gynecologic oncology, 122.5 in reproductive endocrinology and infertility, and 626 in introduction of new technology. Although these programs were diversified, many emphasized the introduction of new technology, which does not enhance the designation of the specialty as "primary care."

Curriculum↗

Quantitation of growth factors in ossein-mineral-compound.

Study was undertaken to identify polypeptide factors in the commercially available ossein-mineral-compound and to see if they are present in a biologically relevant quantity. Using the guanidine-EDTA extraction, 35.7 +/- 0.1 mg proteins were obtained from 1 g of the ossein-mineral-compound. At concentration 1 micrograms/ml, guanidine-EDTA-extractable proteins stimulated the incorporation of thymidine into DNA by human bone cells to 581 +/- 122% (p less than 0.001) of that by bovine serum albumin-treated control cells, decreasing thereafter. Similarly, it stimulated the activity of alkaline phosphatase in the human bone cells. Growth factors IGF-I, IGF-II, and TGF-beta were identified in the ossein-mineral-compound. This leads to speculation regarding possible role of growth factors in explaining the beneficial effects of the compound in retarding bone loss in patients with osteoporosis.

Animals↗