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Biomedical subjects

J Wood

Publications and source records attributed to J Wood.

At least 253 records · Page 14Linked to original sources
PubMed1982

Analytical electron microscopic evaluation of the effects of paraformaldehyde pretreatment on the reaction of glutaraldehyde with biogenic amines.

Analytical electron microscopy was used to determine the quantitative effects of paraformaldehyde pretreatment on the formation of the biogenic amine-glutaraldehyde-chrome complex. Pretreatment with paraformaldehyde prevented the glutaraldehyde-chrome reaction with norepinephrine in the rat adrenal medulla. In contrast to the effect of paraformaldehyde on norepinephrine, pretreatment did not prevent the chrome reaction in serotonin-containing argentaffin cells of the gut. X-Ray energy spectrographic analysis revealed a significant decrease in chrome content in the paraformaldehyde treated tissue, but sufficient chrome did react to produce an electron-dense product. Thus by treating tissue with paraformaldehyde prior to the glutaraldehyde chrome procedure, serotonergic sites may be differentiated from catecholaminergic areas at the electron microscopic level.

Adrenal Medulla↗
PubMed1982

Influence of tetrahydrouridine on the pharmacokinetics of intrathecally administered 1-beta-D-arabinofuranosylcytosine.

Tetrahydrouridine (THU), a potent inhibitor of cytidine deaminase, has been shown to increase the antitumor activity of 1-beta-D-arabinofuranosylcytosine (ara-C) both in vitro and in vivo. In initial studies, which examined the cerebrospinal fluid (CSF) pharmacokinetics of intrathecally (i.t.) administered THU, the drug was found to be slowly cleared from the CSF with alpha and beta half-lives of 1 and 8 hr, respectively. In subsequent experiments, both i.v. pretreatment with THU and concomitant i.t. injection of THU were found to retard the disappearance of i.t. ara-C from the CSF, although the effect of i.t. THU was more profound. ara-C given alone was cleared from CSF with alpha and beta half-lives of 27.5 +/- 6.7 and 115.6 +/- 0.4 (S.D.) min, respectively. Pretreatment with i.v. THU resulted in alpha and beta half-lives of 10.4 +/- 1.5 and 85.7 +/- 11.1, respectively, whereas concomitant administration of i.t. THU resulted in a single half-life of 96 +/- 0.7. The mean calculated clearance rates for ara-C alone, ara-C plus i.v. THU, and ara-C plus i.t. THU were 7.5, 6.2, and 4.2 ml/hr, respectively. This effect appeared to be primarily due to THU inhibition of ara-C deamination, since a decrease in formation of 1-beta-D-arabinofuranosyluracil in the CSF was observed when ara-C was given in the presence of THU (either i.t. or i.v.). No acute neurotoxicity was noted after administration of either i.t. THU alone or i.t. THU with ara-C. The ability of THU to alter CSF ara-C pharmacokinetics may have potential therapeutic value.

Animals↗
PubMed1981

Pregnancies in humans by fertilization in vitro and embryo transfer in the controlled ovulatory cycle.

Normal pregnancies have been established in four women with tubal infertility by fertilization in vitro, embryo culture, and embryo transfer after stimulation of follicular growth with clomiphene citrate. In three of these women the time of oocyte maturation was controlled by human chorionic gonadotropin. This procedure for the control of ovulatory response has many advantages when compared with the previously successful method of using the natural ovulatory cycle.

Chorionic Gonadotropin↗
PubMed1981

A clinical assessment of nine pregnancies obtained by in vitro fertilization and embryo transfer.

An analysis of nine pregnancies resulting from in vitro fertilization and embryo transfer was made in order to identify factors common to all of the pregnancies. These factors included clomiphene stimulation; general anesthesia for laparoscopy; identification of large follicles (greater than 8 ml) and a mature oocyte; preincubation of the oocyte for 4.7 to 6.5 hours in vitro before insemination; insemination with 0.8 to 1.3 x 10(6) fresh spermatozoa from fertile samples; transfer to the uterus of two-, four-, and eight-cell embryos, 38 to 50 hours after insemination; and uncomplicated uterine transfers of embryos. It was difficult to determine whether these factors are causal or coincidental in the attainment of successful pregnancies. The detailed analysis was useful in demonstrating factors which did not prevent the establishment of pregnancy by in vitro fertilization and embryo transfer. These factors included a variety of causes of infertility, including idiopathic and male infertility; age of the infertile woman over 35 years; the presence of T-mycoplasma in the genital tract; the use of human chorionic gonadotropin; a variety of agents used for general anesthesia; the use of carbon dioxide to induce pneumoperitoneum; a delay of up to 50 minutes in the interval between the induction of general anesthesia and oocyte recovery; the use of antiprostaglandins at the time of embryo transfer; and a brown discharge from the vagina following embryo transfer.

Embryo Transfer↗
PubMed1981

Etiology of acute conjunctivitis in children.

To determine the etiology of acute conjunctivitis in children seen in pediatric practice, 99 patients with conjunctivitis and 102 age-and season-matched controls were cultured for aerobic bacteria including Haemophilus influenzae, and for viruses, Chlamydia trachomatis, and mycoplasmas. Agents statistically associated with conjunctivitis included H. influenzae (42% vs 0%), Streptococcus pneumoniae (12% vs 3%), and adenoviruses (20% vs 0%). One of these three etiologic agents was isolated from 71 (72%) of the patients. Simultaneous infection with two pathogens was uncommon. Staphylococcus aureus was equally prevalent in diseased and control eyes; one strain of C. trachomatis was isolated from a control eye. Although there were variations in the clinical features of viral and bacterial conjunctivitis, differentiation in an individual patient was difficult. An adenovirus was isolated from 11 (65%) of 17 patients who had pharyngitis in addition to conjunctivitis. H. influenzae was isolated from 14 (74%) of 19 children who had both otitis and conjunctivitis. Adenovirus conjunctivitis was common in the fall and H. influenzae in winter.

Acute Disease↗
PubMed1981

Surface colonies of Leptospira interrogans.

Observations of colonial growth of Leptospira interrogans serovar pomona, BJ, on soft-agar (1% agar) plates revealed the presence of both surface and subsurface colonies. The organisms from both types of colonies appeared to be similar in motility, morphology, antigenic composition, and pathogenicity. Passage in vivo tended to produce a higher incidence of surface colonies, whereas passage in vitro tended to produce a higher incidence of subsurface colonies, suggesting the importance of environmental factors in determining the type of colony produced.

Antigens, Bacterial↗
PubMed1980

The pattern of termination of ventral tegmental afferents into nucleus accumbens: an anterograde HRP analysis.

The input pattern from the ventral tegmental area (VTA) to the nucleus accumbens was examined using the anterograde transport of HRP. Following an injection of HRP into the VTA, marked heterogeneity was seen in accumbens especially in caudal regions. Here, the terminals were restricted for most part in the dorsal portions of accumbens. In rostral accumbens, the pattern was more uniform across accumbens. Glyoxylic acid induced histofluorescence supported these findings. The present results demonstrate considerable complexity in the rostral-caudal termination pattern of A10 afferent within the nucleus accumbens.

Afferent Pathways↗
PubMed1980

A quantitative analysis of ethanol and acetaldehyde expired by inbred mouse strains.

Expired ethanol and acetaldehyde were measured after an oral injection of ethanol in C57BL/6J and DBA/2J mouse strains by a combination of several techniques in a sequence involving a method for trapping expired radioactive compounds, separation of compounds by gas chromatography, isolation of radioactive ethanol and acetaldehyde, and their quantitative analysis by liquid scintillation spectrophotometry. With the specific activities used in evaluation of the technique (0.1 Ci/mole, acetaldehyde; 1.1 Ci/mol, ethanol) the lower limit of sensitivity using 500 microliters from a 10 ml trap is 955 pmoles for acetaldehyde and 101 pmoles for ethanol. However, in the animal experiments, injected ethanol has a specific activity of 1.1 Ci/mol which would make the specific activity of expired metabolically formed acetaldehyde the same. This results in a lower limit of sensitivity for acetaldehyde of 80 pmoles. The two strains were monitored for 80 min following an oral injection of 3.8 g/Kg of (2-14C) ethanol. Comparing the two strains on the expiration of each compound the curves were identical.

Acetaldehyde↗
PubMed1980

Latency of pancreatic enzyme response to intraduodenal stimulants.

In six dogs with pancreatic fistulas, secretin (500 ng . kg-1 . h-1) was given to provide a flow of pancreatic juice of about 1 drop/s. Amylase concentration was measured in each drop before and after rapid intraduodenal injection of L-tryptophan, sodium oleate, and NaCl or after rapid intraportal injection of cholecystokinin (CCK). Latency of response (time between injection and a sustained increase in amylase output greater than the mean + 3 SD of prestimulation output) was 0.30 min to tryptophan and 0.33 min to oleate. These were significantly (P less than 0.01) less than the latency to intraportal CCK (0.53 min). Atropine and truncal vagotomy increased the latency to tryptophan and oleate 10-fold but had no effect on the latency to intraportal CCK. We conclude that, since the latency of amylase response to intraduodenal stimulants was shorter than to intraportal CCK, the initial response is probably not due to release of hormones. The finding that atropine and vagotomy increased latency of response to intraduodenal stimulants indicates that a vagovagal cholinergic reflex mediates the early pancreatic enzyme response to intestinal stimulants.

Amylases↗