Biomedical subjects

M F Smith

Publications and source records attributed to M F Smith.

At least 145 records · Page 8Linked to original sources

PubMed1993

The human interleukin-1 receptor antagonist (IL1RN) gene is located in the chromosome 2q14 region.

The gene for human interleukin-1 receptor antagonist (IL1RN) has been assigned to chromosome 2 on the basis of Southern blot analysis of a series of human-Chinese hamster cell hybrids. Using a yeast artificial chromosome containing the IL1RN gene as a probe, the human IL1RN gene was localized to the long arm of chromosome 2 at band 2q14.2 by fluorescence in situ hybridization. This site is near the positions of genes for human IL-1 alpha, IL-1 beta, and types I and II IL-1 receptors, as reported by other laboratories.

Animals↗

PubMed1993

Basis of norgestomet action as a progestogen in cattle.

Norgestomet is the progestational component present in Syncro-Mate-B, which is used to synchronize estrus in cattle. In post-partum cows, luteal phases anticipated to be short following first ovulation are of normal length when cows are pretreated with norgestomet. Because Syncro-Mate-B is used experimentally as a progestogen to affect uterine function, these studies were conducted to investigate how norgestomet acts at the level of the uterus. Receptor binding assays and a sensitive estrogen bioassay in tissue culture were used to address the possibility that some effects of norgestomet might be mediated through interaction of this compound with steroid hormone receptors other than the progesterone receptor (rP). The source of receptors was high-speed cytosol, prepared from bovine uterine endometrium, which was obtained from cyclic cows. Results of single-point and complete competition analyses comparing norgestomet and progesterone indicated that norgestomet competed even more effectively than did progesterone for specific binding of [3H]progesterone to rP. Results of similar studies, which compared the abilities of norgestomet and diethylstilbestrol to compete with [3H]estradiol for binding by uterine endometrial estrogen receptors (rE), provided no evidence for norgestomet competitive binding to rE. In MCF-7 breast cancer cell bioassays, norgestomet showed weak estrogenic activity, but only at concentrations greater than 1 micromolar. Finally, norgestomet did not compete with [3H]triamcinolone acetonide when present in an 100-fold excess, and only competed with [3H]dexamethasone for binding by endometrial glucocorticoid receptors (rG) when present in the micromolar range. We conclude that, at the concentrations used in synchronizing estrus, norgestomet interacts with bovine endometrium as a progestogen and that its biological actions occur through binding of this compound to rP present in target tissues.

Animals↗

PubMed1993

Detection of mRNA for inhibin alpha- and beta A-subunits in bovine ovarian tissues and the effect of in vivo administration of GNRH.

The aims of these studies were to determine which types of bovine ovarian tissue contain mRNA for inhibin/activin subunits and whether administration of GnRH influences concentration of these mRNAs. In experiment (exp.) one, cows in the luteal phase of the estrous cycle were given prostaglandin F2 alpha (PGF2 alpha) to induce luteal regression and injected after 40 hr with saline (n = 5) or 100 micrograms GnRH (n = 6). Ovaries were removed 6 hr later. In exp. two, unilaterally ovariectomized (OVX) heifers (n = 33) in the luteal phase of their estrous cycle were given PGF2 alpha to induce luteal regression. Twelve heifers were OVX without injection of GnRH at 24 (n = 6) or 40 hr (n = 6) after PGF2 alpha. The remaining heifers (n = 21) were given 100 micrograms GnRH at 40 hr after PGF2 alpha injection and OVX 8 (n = 4), 16 (n = 5), 24 (n = 6) or 48 (n = 6) hr after GnRH injection. Total cellular RNA was isolated from large follicles (exp. one and two), small-medium follicles and stromal tissue (SMS) and corpora lutea (CL; exp. one) tissues and analyzed by dot blot and Northern blot techniques by hybridizing with cDNA probes for human inhibin/activin alpha- and beta A-subunits. Large follicles were classified as steroidogenically active (EA) if follicular fluid (FF) concentration of estradiol-17 beta (E2) was greater than progesterone (P4), or if P4 and E2 concentrations in FF were greater than 100 ng/ml, and estrogen inactive (EI) if FF concentration of E2 and P4 did not satisfy these criteria. In exp. one, mRNA for the alpha-subunit was primarily expressed in EA follicles, and detectable in EI follicles, SMS, and CL while beta A-subunit mRNA was detected only in large EA follicles and a few SMS samples. The mRNA (x +/- SEM fmoles/mg DNA) for both subunits of inhibin/activin was higher (P < .05) in EA follicles from GnRH-treated cows (alpha = 210.2 +/- 38.6; beta A = 376.9 +/- 41.0) than in EA follicles from control cows (alpha = 102.5 +/- 28.6; beta A = 170.8 +/- 57.6). Concentration of mRNA for the alpha-subunit of inhibin in other ovarian tissues was not different (P > .10) between saline and GnRH treatments.(ABSTRACT TRUNCATED AT 400 WORDS)

Activins↗

PubMed1993

Effects of intraoperative 5-fluorouracil or mitomycin C on glaucoma filtration surgery in the rabbit.

PURPOSE: To establish the effects of single intraoperative exposures to either 5-fluorouracil (5-FU) or two different concentrations of mitomycin C (MMC) on filtration surgery in the rabbit. METHODS: A prospective, randomized, masked-observer, placebo-controlled study was performed to compare the effects on filtration surgery in rabbits of a single 5-minute intraoperative exposure to 5-FU (50 mg/ml), MMC (0.2 mg/ml), or MMC (0.4 mg/ml) with control eyes treated with distilled water. RESULTS: Intraocular pressures (IOPs) remained lower for longer and bleb survival was increased (P < 0.05) with all three treatments compared with control eyes. The effect of 5-FU was more transient than MMC. Bleb survival was prolonged in the following order: MMC 0.4 > MMC 0.2 > 5-FU 50 mg/ml. At 30 days, blebs were present in 100% of eyes treated with MMC 0.4 mg/ml, 60% of eyes treated with MMC 0.2 mg/ml, and 0% of eyes treated with 5-FU 50 mg/ml or distilled water. The blebs in the eyes treated with MMC were thinner, and significant complications (endophthalmitis, transient corneal opacification and neovascularization, and a presumed bleb leak) only occurred in the eyes treated with MMC 0.4 mg/ml. CONCLUSIONS: The authors' results suggest that 5-FU and MMC at these concentrations, delivered as a single intraoperative dose, prolong the survival of filtration surgery for different lengths of time in the rabbit, which is a model that normally exhibits aggressive healing and rapid failure of filtration surgery. The implications of these potentially titratable effects for filtration surgery in different categories of patients are discussed.

Animals↗

PubMed1993

Prevention of early hypotony associated with Molteno implants by a new occluding stent technique.

BACKGROUND: A major complication of unvalved drainage tube implants is hypotony. Occluding stents to internally block the tube, but which lie exposed in the inferior fornix, have been described. The authors report modifications of this technique. METHODS: A nonexposed 3-0 Supramid suture is used to internally block the tube, with the end placed subconjunctivally. Small venting slits are made in the extrascleral portion of the tube to provide early control of intraocular pressure. Molteno implants were placed in 32 eyes of 29 patients using these modifications. RESULTS: Mean preoperative intraocular pressure was 30.3 mmHg on an average of 2.6 medications. The stent was pulled without difficulty in the office treatment room a mean of 26 days postoperatively. Intraocular pressure from postoperative day 2 until the day of stent removal ranged from 2 to 26 mmHg, with 72% of eyes having intraocular pressure between 5 and 19 mmHg. There were 3 (9.4%) minor complications in the 32 eyes, with 1 case of early anterior chamber shallowing and 2 cases of moderate choroidal detachments, which settled spontaneously. With an average follow-up of 10.2 months, mean intraocular pressure at the final visit was 13.4 mmHg on an average of 1 medication. CONCLUSION: The "occluding stent" described here can be a helpful adjunct to unvalved drainage tube surgery in preventing early postoperative hypotony.

Adolescent↗

PubMed1993

Female reproductive physiology and endocrinology of cattle.

Maximizing reproductive efficiency is of major economic importance to dairy and beef producers. The development of new and improved methods of increasing reproductive performance depends on our understanding of the physiologic and endocrinologic mechanisms controlling the reproductive process. This article reviews the mechanisms associated with puberty, estrous cycles, pregnancy, parturition, and postpartum return to estrus.

Anestrus↗

PubMed1993

Modelling photon transport in non-uniform media for SPECT with a vectorized Monte Carlo code.

A vectorized Monte Carlo code has been developed for modelling photon transport in non-uniform media for single-photon-emission computed tomography (SPECT). The code is designed to compute photon detection kernels, which are used to build system matrices for simulating SPECT projection data acquisition and for use in matrix-based image reconstruction. Non-uniform attenuating and scattering regions are constructed from simple three-dimensional geometric shapes, in which the density and mass attenuation coefficients are individually specified. On a Stellar GS1000 computer, Monte Carlo simulations are performed between 1.6 and 2.0 times faster when the vector processor is utilized than when computations are performed in scalar mode. Projection data acquired with a clinical SPECT gamma camera for a line source in a non-uniform thorax phantom are well modelled by Monte Carlo simulations. The vectorized Monte Carlo code was used to stimulate a 99Tcm SPECT myocardial perfusion study, and compensations for non-uniform attenuation and the detection of scattered photons improve activity estimation. The speed increase due to vectorization makes Monte Carlo simulation more attractive as a tool for modelling photon transport in non-uniform media for SPECT.

Humans↗

PubMed1993

Identification of a 30,000 M(r) polypeptide secreted by cultured ovine granulosa cells and luteal tissue as a tissue inhibitor of metalloproteinases.

Previous studies have revealed that the gonadotropin surge initiates, via transcriptional mechanisms, synthesis and secretion of a 30,000 M(r) polypeptide by the granulosa cells of ovine preovulatory follicles. This polypeptide also appears to be secreted by luteal tissue and has been tentatively identified as a tissue inhibitor of metalloproteinases (TIMP; 68% NH2-terminal amino acid sequence identity to a human TIMP). Therefore, the objective of the present study was to confirm that TIMP is produced by granulosa cells and luteal tissue in the ewe. A series of experiments was conducted to determine whether the 30,000 M(r) polypeptide secreted by granulosa cells and luteal cells is similar to TIMP in biochemical properties (degree of N-linked glycosylation), in biological activity (as ascertained by gelatin zymographic analysis), and in immunoreactivity (as ascertained by Western blot analysis). Incubation of granulosa cells or luteal cells with tunicamycin revealed that the 30,000 M(r) polypeptide is glycosylated. The form lacking N-linked chains had an M(r) (approximately 20,000) similar to that of the unglycosylated form of TIMP in other species. Gelatin zymographic analysis detected significant metalloproteinase inhibitor activity associated with polypeptides of M(r) approximately 21,000 and 30,000 secreted by granulosa cells and luteal cells. Northern hybridization of granulosa cell RNA and Day 10 luteal RNA with an anti-sense TIMP oligonucleotide probe detected an approximately 900-base transcript, which is similar in size to that reported for TIMP mRNA in other species. Finally, Western blot analysis with a rabbit anti-human TIMP antiserum detected immunoreactive polypeptides of M(r) 30,000 secreted by granulosa cells and luteal cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Molecular evidence for mating asymmetry and female choice in a pocket gopher (Thomomys) hybrid zone.

This paper presents circumstantial evidence that the mating system of the North American pocket gophers (Rodentia: Geomyidae) is a promiscuous one, with female choice at its base. A molecular marker (a length variant in the mitochondrial Control region [D-loop]) is used to show mating asymmetry in a hybrid zone between the species Thomomys bottae and Thomomys townsendii in north-eastern California. All hybrids result from a bottae mother x townsendii father cross. Because of significant differences in body size and resulting burrow diameter, bottae females must have actively sought their respective townsendii mates for the asymmetry in mating to have occurred, signalling female choice in these subterranean mammals that are otherwise characterized by exclusive-use territories, skewed adult sex ratio in favour of females, and high variance in male reproductive success.

Animals↗

PubMed1993

Apoptosis during luteal regression in cattle.

The present studies were conducted to evaluate whether apoptosis occurs during spontaneous and prostaglandin F2 alpha (PGF2 alpha)-induced luteolysis and, if so, to determine the relationship between the onset of luteolysis and oligonucleosome formation (a characteristic of apoptosis). In the first study, nine normally cycling heifers were ovariectomized (ovx) during the midluteal phase (day 10 or 15; day 0 = estrus) or after luteal regression (day 19; n = 3/time point). While there was no evidence of oligonucleosome formation in DNA from corpora lutea (CL) collected on days 10 and 15, each CL collected on day 19 exhibited DNA fragmentation, represented by distinct bands of DNA in approximately 185-basepair multiples. In the second study, heifers were ovx (n = 5; controls) or given 25 mg PGF2 alpha 15-16 days after estrus. Heifers receiving PGF2 alpha were subsequently ovx 4, 8, 12, 24, or 48 h (n = 5/time point) after the injection of PGF2 alpha. The concentration of progesterone in venous sera collected at ovx was not different (P > 0.20) in control and 4 h groups, but was decreased (P < 0.01) in the 8, 12, 24, and 48 h groups. Total CL weight (mean +/- SEM; grams) did not change (P > 0.10) from 0 h (controls) to 24 h after injection (range, 3.2 +/- 0.5 to 4.1 +/- 0.6), but decreased (P < 0.06) to 2.0 +/- 0.3 at 48 h. With ethidium bromide (EtBr) staining, no oligonucleosome formation was detected in CL collected from 0-12 h after PGF2 alpha injection. However, pronounced oligonucleosome formation was observed in all 10 CL collected 24 and 48 h after the injection of PGF2 alpha. The absence of oligonucleosomes in 0 and 4 h samples was confirmed by the more sensitive technique of 3'-end labeling of DNA fragments. Some samples in both the 8 and 12 h groups had slight oligonucleosome formation, while all samples in the 24 and 48 h groups showed evidence of intense oligonucleosome formation. Histological analysis of tissue sections indicated an increase (P < 0.001) in the percentage of degenerated luteal cells in the 24 and 48 h groups compared to that in the 0-12 h groups. These data indicate that apoptosis occurs during both spontaneous and PGF2 alpha-induced luteal regression in cattle; however, apoptosis, as indicated by oligonucleosome formation, is not apparent until after serum progesterone concentrations have begun to decrease.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1993

Concentrations of progesterone and oxytocin receptors in endometrium of postpartum cows expected to have a short or normal oestrous cycle.

Luteal lifespan is short after first postpartum ovulation in early-weaned beef cows unless cows are pretreated with a progestogen. Regression of the short-lived corpus luteum in the postpartum beef cow is due to a premature release of prostaglandin F2 alpha (PGF2 alpha) from the uterus. The premature release of PGF2 alpha may be mediated through lower concentrations of receptors for progesterone, higher concentrations of oxytocin receptors, or both, in the endometrium. Thirty-one beef cows were randomly assigned to four groups at parturition. Calves from cows assigned to the short cycle group (n = 6; control) and the short cycle/endometrium group (n = 10) were weaned at 30-32 days post partum. Cows in the normal cycle group (n = 5; control) and the normal cycle/endometrium group (n = 10) received norgestomet implants for 9 days beginning 21-23 days post partum and calves were weaned at implant insertion. Duration of oestrous cycle (x +/- SEM; P < 0.01) following first postpartum ovulation for the short cycle group was 11.5 +/- 1.9 days compared with 18.8 +/- 0.6 days for the normal cycle group. On day 5 following first postpartum ovulation, cows in the short cycle/endometrium and the normal cycle/endometrium groups were hysterectomized and endometrial tissue collected for measurement of progesterone and oxytocin receptors. Mean number of total progesterone receptors per cell was lower (P < 0.05) in the short cycle/endometrium group than in the normal cycle/endometrium group. Mean concentration of oxytocin receptors (fmol mg-1 protein) in the short cycle/endometrium group was higher (P < 0.05) than that in the normal cycle/endometrium group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Intraoperative 5-fluorouracil for filtration surgery in the rabbit.

PURPOSE: Postoperative subconjunctival injections of 5-fluorouracil (5-FU) improve the success rate of filtration surgery, but there is still a 20% or greater failure rate at 1 year in pseudophakic and repeat trabeculectomy cases. The injections are inconvenient to give and may produce corneal epithelial toxicity and other side effects. An alternative method for administration of 5-FU is investigated. METHODS: A masked, randomized, prospective study was undertaken to compare bleb survival and complications in a rabbit model, after either a single intraoperative exposure to 5-FU (50 mg/ml concentration for 5 minutes) or five postoperative injections of 5-FU (5 mg injection on postoperative days 1, 3, 5, 7, and 9), or a combination of both, with controls that received only a 5-minute exposure to distilled water, intraoperatively. RESULTS: For the control eyes, all blebs were "flat" to masked grading, and intraocular pressure returned to preoperative levels by postoperative day 11. In the group receiving postoperative injections of 5-FU only, blebs were flat and the pressure normalized by postoperative day 14. Rabbits receiving intraoperative 5-FU only, or combined intraoperative and postoperative 5-FU, had consistently higher blebs than the former two groups, and some blebs survived until postoperative day 25. The mean intraocular pressure remained depressed in these groups until postoperative day 21 (P < 0.05 for days 5 through 18). A combination of intraoperative and postoperative 5-FU produced significantly higher blebs than intraoperative 5-FU alone on days 7 to 14. CONCLUSIONS: Intraoperative application of high-dose 5-FU to the filtration site either as a single 5-minute treatment, or in conjunction with postoperative injections of 5-FU greatly prolongs bleb function after filtration surgery in the rabbit.

Animals↗

PubMed1993

Drainage tube implants in the treatment of glaucoma following penetrating keratoplasty.

A retrospective review was undertaken to compare outcomes in 26 eyes that underwent penetrating keratoplasty (PKP) and drainage tube surgery (Molteno double-plate implant or Schocket procedure). Drainage tube surgery was performed either before PKP (10 eyes), after PKP (7 eyes), or at the same time as PKP (9 eyes). Mean follow up was 22 months. The average preoperative intraocular pressure (IOP) for all of the eyes was 31 mm Hg; 96% of them achieved a final IOP of less than 18 mm Hg (average, 14 mm Hg on a mean of 0.8 medications). Graft failure occurred in 11/26 (42%). Eight of these eyes were regrafted, and six of these eight have remained clear at a mean follow up of 22 months after regrafting. The overall PKP success rate, including the eyes that underwent repeat PKP, was 81%. Visual acuity remained stable or improved in 70% of the eyes.

Adolescent↗

PubMed1992

Results of intraoperative 5-fluorouracil supplementation on trabeculectomy for open-angle glaucoma.

The success rate of filtration surgery has been increased by the postoperative subconjunctival injection of 5-fluorouracil, a potent antimetabolite. However, the optimal route of administration has not been determined. Trabeculectomy was performed on one eye each of 14 patients. Topical 5-fluorouracil was applied intraoperatively (50 mg/ml for five minutes) and subconjunctival 5-fluorouracil was injected postoperatively (an average of 5.8 injections) (mean total dose, 29 mg). Seven of the 14 eyes had primary open-angle glaucoma, and seven eyes had open-angle glaucoma with either uveitis, aphakia, or previous failed trabeculectomy. Mean preoperative intraocular pressure was 24.7 mm Hg during treatment with an average of three antiglaucoma medications, and mean final intraocular pressure was 11.9 mm Hg during treatment with an average of 0.2 medication. Thirteen of 14 eyes (93%) had final intraocular pressure of 18 mm Hg or less. Mean follow-up was 6.4 months (range, four to nine months). No remarkable complications occurred. Visual acuity remained stable in 13 of 14 eyes (93%). Intraoperative 5-fluorouracil may be a helpful adjunct in achieving low final intraocular pressure after trabeculectomy.

Administration, Topical↗

PubMed1992

Human IL-1 receptor antagonist promoter. Cell type-specific activity and identification of regulatory regions.

To study the molecular mechanisms involved in transcriptional regulation of the human IL-1R antagonist (IL-1ra) we have isolated 1680-bp of 5'-flanking region DNA from the IL-1ra gene. This region of DNA was sequenced and cloned into the luciferase expression vector pA3Luc (pRA-1680.Luc) for use in gene transfer studies aimed at determining the cis-acting DNA elements required for IL-1ra expression. Sequence analysis of the IL-1ra promoter revealed a TATAA box at -26, with consensus sequences for possible NF-kB-, NFIL-1 beta A-, AP-1-, and CRE-binding sites located further upstream. When transfected into a variety of human and murine cell lines, the cloned IL-1ra promoter was preferentially active in those cell lines in which expression of the endogenous IL-1ra gene could be detected. The cloned promoter and the endogenous IL-1ra promoter utilized the same transcriptional start site. This promoter activity was LPS-inducible in the RAW 264.7 murine macrophage cell line. In the human monocytic cell line U937, IL-1ra promoter activity was inducible by LPS or PMA treatment, but the combination of LPS and PMA led to the greatest increase in promoter activity, identical to the pattern of expression of endogenous IL-1ra mRNA as detected by polymerase chain reaction analysis. A series of 5'-truncated promoter constructs having a common 3'-end at +27 were created to map potential cis-acting transcriptional elements important for full IL-1ra promoter activity. Removal of sequences between -294 and -148 led to a greater than 90% decrease in both unstimulated and LPS-induced promoter activity; further deletion to -85 led to an almost complete abrogation of promoter activity. These studies demonstrate that the cloned IL-1ra promoter behaves in a manner consistent with that of the endogenous gene. Two regions within the IL-1ra promoter are identified which are required for full promoter activity.

Animals↗

PubMed1992

Quantitation of molecular densities by cryo-electron microscopy. Determination of the radial density distribution of tobacco mosaic virus.

We have determined the absolute mass and radial scattering density distribution of tobacco mosaic virus in the frozen-hydrated state by energy-filtered low-dose bright-field transmission electron microscopy. The absolute magnitude of electron scattering from tobacco mosaic virus in 150 nm of ice was within 3.0% of that predicted, with inelastic scattering accounting for approximately 80% of the scattering contrast. In order to test the accuracy of the radial reconstruction, a computer model of tobacco mosaic virus was built from the atomic co-ordinates assuming uniform solvent density. The validity of the model was confirmed by comparison of X-ray scattering and predictions of the model (R factor = 0.05). First-order corrections for the microscope contrast transfer function were necessary and sufficient for conversion of the cryo-electron microscopy images into accurate representations of the mass density. At 1.9 nm resolution the compensated reconstruction and model had density peaks of similar magnitude at 2.4, 4.2, 6.0 and 7.8 nm radius and a central hole of 2 nm radius. Equatorial Fourier transforms of the corrected electron images were in excellent agreement with predictions of the model (R factor = 0.12). Thus, the uniform solvent approximation was adequate at 1.9 nm resolution to describe quantitatively X-ray scattering in liquid water and electron imaging in vitreous ice. This is the first demonstration that cryo-electron microscopy images can be used to quantitate the absolute mass, mass per unit length and internal density distributions of proteins and nucleic acids.

Computer Simulation↗

PubMed1992

Comparison of the double-plate Molteno drainage implant with the Schocket procedure.

A randomized, prospective study was undertaken to compare the results of the double-plate Molteno implant with those of the anterior chamber tube shunt to encircling band (ACTSEB) procedure, described by Schocket, for eyes with complicated glaucoma. One surgeon performed all the procedures. For statistical analysis there were 21 eyes in the ACTSEB group and 19 eyes in the Molteno group, with at least 6 months of follow-up (mean follow-up, 26 months; range, 6 to 49 months). Eyes with aphakia/pseudophakia, uveitis, previous penetrating keratoplasty, previous unsuccessful trabeculectomy, and neovascular glaucoma were evenly distributed between the two groups. Mean preoperative intraocular pressures in the ACTSEB and Molteno groups were 35.2 and 34.6 mm Hg, respectively. With the exclusion of one phthisical eye in each group final mean intraocular pressure in the ACTSEB group was 15.1 mm Hg, with a mean of 0.43 medications, and 14.4 mm Hg, with a mean of 0.95 medications, in the Molteno group. Seven (33%) of 21 eyes and 13 (68%) of 19 eyes in the ACTSEB and Molteno groups, respectively, were receiving additional antiglaucoma medication at the most recent visit (P = .027). Final visual acuity was stable (within one Snellen line of baseline visual acuity) or improved in 10 (48%) of 21 eyes in the ACTSEB group compared with 13 (68%) of 19 eyes in the Molteno group. Complications or inadequate pressure control requiring further surgical intervention were seen in nine (47%) of 19 eyes in the Molteno group and 12 (57%) of 21 eyes in the ACTSEB group.(ABSTRACT TRUNCATED AT 250 WORDS)

Drainage↗

PubMed1992

Homozygous acute intermittent porphyria: compound heterozygosity for adjacent base transitions in the same codon of the porphobilinogen deaminase gene.

A sister and brother with severe porphobilinogen (PBG) deaminase deficiency are described. Each of their parents carries a different mutation for acute intermittent porphyria and the children are homozygous for the PBG-deaminase deficiency that causes this disorder. Both are compound heterozygotes for adjacent base transitions in the same codon in exon 10 of the PBG deaminase gene.

Base Sequence↗