Transition of a dental histology course from light to virtual microscopy.

The transition of the dental histology course at the University of Texas Health Science Center at San Antonio Dental School was completed gradually over a five-year period. A pilot project was initially conducted to study the feasibility of integrating virtual microscopy into a traditional light microscopic lecture and laboratory course. Because of the difficulty of procuring quality calcified and decalcified sections of teeth, slides from the student loan collection in the oral histology block of the course were outsourced for conversion to digital images and placed on DVDs along with a slide viewer.

Pulmonary expression of the human haptoglobin gene.

Haptoglobin (Hp), a member of the acute-phase reactants, has long been known as a major hemoglobin-binding protein associated with hemoglobin catabolism. Recent studies indicate that another important biologic function of Hp is the modulation of the immune response. We found that Hp is expressed at high levels in specific cells, including alveolar macrophages and eosinophils in diseased or inflamed human lung tissues, but not in the normal lung.

A comparison of the suppression of human transferrin synthesis by lead and lipopolysaccharide.

Transferrin, as the major iron-transport protein in serum and other body fluids, has a central role in managing iron the body receives. Liver is a major site of transferrin synthesis, and in this study we present evidence that liver synthesis of human transferrin is suppressed by both the toxic metal lead and bacterial lipopolysaccharide, an inducer of the hepatic acute phase response. The responses of intact endogenous transferrin in the human hepatoma cell line HepG2 and chimeric human transferrin-chloramphenicol acetyltransferase genes in transgenic mice were examined.

Mg(2+)-dependent and Ca2+, Mg(2+)-dependent ATPase activities in the harderian gland of rodents: age and sex influences.

Three experiments employing male and female Syrian hamsters (aged 1, 2, and 8-10 months), male Sprague-Dawley rats (aged 1, 2, and 10 months) and male C57B1 mice (aged 2, 7, 13, and 29 months) examined the effects of age and sex on Mg(2+)-dependent and Ca2+, Mg(2+)-dependent ATPase activity in the Harderian gland. Significant differences due to age and sex were observed in the hamsters and rats but not with age in mice. Generally, male hamsters had significantly higher Mg(2+)-dependent and Ca2+, Mg(2+)-dependent (exception at one timepoint) ATPase activity than did females.

Cellular expression of ceruloplasmin in baboon and mouse lung during development and inflammation.

Ceruloplasmin (CP) is an important extracellular antioxidant and free radical scavenger. Although CP is expressed mainly in the liver, recent studies have identified the lung as another major site of CP synthesis. The sites and cell types that are responsible for CP expression in baboon and mouse lung are described.

Targeted overexpression of androgen receptor with a liver-specific promoter in transgenic mice.

The rodent liver displays marked age- and sex-dependent changes in androgen sensitivity due to the sexually dimorphic and temporally programmed expression of the androgen receptor (AR) gene. We have altered this normal phenotype by constitutive overexpression of the rat AR transgene in the mouse liver by targeting it via the human phenylalanine hydroxylase (hPAH) gene promoter. These transgenic animals in their heterozygous state produce an approximately 30-fold higher level of the AR in the liver as compared with the nontransgenic control.

YY1 and Sp1 transcription factors bind the human transferrin gene in an age-related manner.

The iron-binding protein transferrin has major roles in transporting, delivering, and sequestering ferric ions acquired by body tissues. Yet, during aging, serum transferrin levels decrease in humans. Likewise, in transgenic mice carrying chimeric human transferrin transgenes, liver expression of transferrin transgenes decreases with age.

Discovery of a brain promoter from the human transferrin gene and its utilization for development of transgenic mice that express human apolipoprotein E alleles.

Transgenic mice carrying heterologous genes directed by a 670-bp segment of the regulatory sequence from the human transferrin (TF) gene demonstrated high expression in brain. Mice carrying the chimeric 0.67kbTF-CAT gene expressed TF-CAT in neurons and glial cells of the nucleus basalis, the cerebrum, corpus callosum, cerebellum, and hippocampus.

Age-specific regulation of clotting factor IX gene expression in normal and transgenic mice.

Factor IX (FIX), a circulating serine protease that serves as an essential component of the blood coagulation pathway, has been shown to increase with age in humans. We show here that murine FIX mRNA and activity levels also increase with age. Furthermore, one form of hemophilia B, hemophilia B Leyden, which is caused by mutations within the promoter region of the FIX gene, has a distinct age-dependent phenotype.

A human (3.3 kb) haptoglobin-CAT transgene is modulated in lungs of transgenic mice by inflammation.

Four independent lines of transgenic mice were produced carrying integrated copies of a chimeric gene composed of 3.3 kb of the human haptoglobin 5' regulatory region fused to the CAT (chloramphenicol acetyl transferase) reporter gene. Although the endogenous mouse haptoglobin (Hp) and human haptoglobin (HP) genes express mainly in liver and lung, expression of the human 3.

Brain and liver targeted overexpression of O6-methylguanine DNA methyltransferase in transgenic mice.

O6-Methylguanine DNA methyltransferase (MGMT; EC 2.1.1.

Expression of chimeric human transferrin-chloramphenicol acetyltransferase genes in liver and brain of transgenic mice during development.

Transferrin (TF) gene expression is tissue specific and is regulated during development. Transgenic mice have been developed which carry 1.2 or 0.

The expression of transferrin mRNA in the salivary glands and other tissues of baboons.

In order to determine whether all the extrinsic salivary glands synthesize transferrin mRNA, the polyadenylated ribonucleic acids [poly(A)+ RNAs] from parotid, submandibular, and sublingual glands, liver, midbrain, testis, spleen, heart, kidney, and the mucosae of oesophagus and stomach from adult male baboons were analysed, using oligo(dT)-cellulose chromatography, agarose gel electrophoresis, followed by transfer of the mRNAs to nitrocellulose filters and identification with transferrin and tubulin cDNA probes. Transferrin and tubulin mRNAs were visualized by autoradiography and analysed by measuring specific activity from beta emitting nuclides following transfer to nitrocellulose filters and hybridizing with [alpha-32P]-labelled human transferrin and tubulin cDNA probes. The results indicate that transferrin mRNA is present in all the extrinsic salivary glands (submandibular, sublingual, parotid) of baboons.

Lead suppresses chimeric human transferrin gene expression in transgenic mouse liver.

The major iron-transport protein in serum is transferrin (TF) which also has the capacity to transport other metals. This report presents evidence that synthesis of human TF can be regulated by the metal lead. Transgenic mice carrying chimeric human TF-chloramphenicol acetyl transferase (CAT) genes received lead or sodium salts by intraperitoneal injections or in drinking water.

Expression of a human chimeric transferrin gene in senescent transgenic mice reflects the decrease of transferrin levels in aging humans.

Transgenic mice provide a means to study human gene expression in vivo throughout the aging process. A DNA sequence containing 668 bp of the 5' regulatory region of the human transferrin gene was fused to the bacterial reporter gene chloramphenicol acetyl transferase (TF-CAT) and introduced into the mouse genome. Expression of the human chimeric transferrin gene was similar to the tissue patterns of mouse and human transferrin.

Tissue specific expression of mouse transferrin during development and aging.

Transferrin (TF) is a major plasma protein that binds ferric iron and transports it to all target tissues of the body. This study is the first step to identify the tissue specific expression of the transferrin gene in mice during development, into maturity and throughout the aging process. The transferrin gene expresses mainly in mouse liver, the cerebral hemispheres and cerebellum.

Human transferrin. Expression and iron modulation of chimeric genes in transgenic mice.

Transferrin (TF) is a plasma protein that transports and is regulated by iron. The aim of this study was to characterize human TF gene sequences that respond in vivo to cellular signals affecting expression in various tissues and to iron administration. Chimeric genes were constructed containing 152, 622, and 1152 base pairs (bp) of the human TF5'-flanking region with the coding region of a reporter gene, CAT (chloramphenicol acetyltransferase), and introduced into the germ line of mice.

Proto-oncogene analyses in brain tumors.

The present study determined which oncogenes (N-myc, c-myc, v-sis, or v-fos) were amplified and which messenger ribonucleic acids (mRNA's) accumulated in 10 primary human brain tumors of neuroectodermal origin. The tumors included four glioblastomas multiforme, one mixed glioma (astrocytoma grade I and ependymoma), one astrocytoma grade II, one cystic cerebellar astrocytoma, one ependymoma, one ganglioglioma, and one medulloblastoma. The relative amounts of polyadenylated (poly(A)+) RNA's homologous to these genes and their copy number were determined using the RNA and deoxyribonucleic acid blot hybridization techniques.

Expression of three viral oncogenes (v-sis, v-myc, v-fos) in primary human brain tumors of neuroectodermal origin.

We determined which viral oncogenes (v-sis, v-myc, and v-fos) were expressed in five primary human brain tumors of neuroectodermal origin (two glioblastomas multiforme, one medulloblastoma, one cystic cerebellar astrocytoma, and one ganglioglioma) and which of these oncogenes is correlated with malignancy. Using the dot hybridization technique, we determined the relative amounts of mRNA coded by these genes using the same nitrocellulose filter. The v-myc probe showed a 4- to 12-fold greater hybridization to the mRNA from two glioblastomas and the medulloblastoma (malignant group) than the mRNA from the cystic cerebellar astrocytoma or the ganglioglioma (benign group).

Nyctohemeral rhythms of gonadal, thyroid and pineal function in the hyperprolactinemic male rat.

In young adult male rats bearing a donor anterior pituitary gland grafted for 3 weeks under a kidney capsule, serum prolactin (PRL) concentrations were elevated and exhibited a rhythm with the highest values in the light phase. Serum PRL in control animals did not exhibit a significant rhythm. Eutopic pituitary PRL content, manifesting a biphasic (12-hr) rhythm with crests during the day and night in controls, exhibited a similar pattern in grafted rats though an overall reduction in pituitary PRL content was seen in the grafted animals.

Uptake and retention of 3H-estradiol by gonadotrophs and lactotrophs in the pituitary glands of the guinea pig, hamster and gerbil.

Nuclear uptake and retention of 3H-estradiol by luteinizing hormone (LH) and prolactin (PRL) cells was examined in three species of rodents (guinea pigs, hamsters and gerbils) using the combined techniques of immunocytochemistry and autoradiography. Castrated animals were injected with 3H-estradiol and decapitated 1.5 h later.

Autoradiographic localization of estrogen target cells in the spinal cord of the armadillo and baboon: a comparative study.

The uptake and retention of radiolabeled estradiol by the spinal cord were examined in the baboon and the armadillo and compared to previous observations in the rat. Four females of each species were injected intracardially with 1.0-1.

Do C cells of the thyroid gland of the baboon contain estrogen receptors?

The uptake and retention of radiolabelled estradiol was studied in the thyroid gland of the female baboon. Four baboons were injected intravenously with 1 micron/kg body weight of 3H-estradiol. One animal, which served as a control, received an additional injection of 100 micrograms/kg body weight of unlabelled hormone.

Nuclear uptake and retention of 3H-dihydrotestosterone or one of its metabolites in the lower brainstem of the baboon.

The nuclear uptake and retention of androgen in the lower brainstem of the baboon was examined after the injection of 3H-5 alpha-dihydrotestosterone. A specific topographical pattern of localization was observed in both motor systems and somatosensory systems. The pattern was similar to that reported in the rhesus monkey.