Engineering bacteria for bioremediation.

The treatment of environmental pollution by microorganisms is a promising technology. Various genetic approaches have been developed and used to optimize the enzymes, metabolic pathways and organisms relevant for biodegradation. New information on the metabolic routes and bottlenecks of degradation is still accumulating, enlarging the available toolbox.

Pituitary carcinoma containing gonadotropins: treatment by radical excision and cytotoxic chemotherapy: case report.

Objective And Importance: Pituitary carcinomas are extremely rare. Cases reported in the medical literature in the 20th century included tumors that produced adrenocorticotropic hormone, prolactin, growth hormone, and/or thyrotropin.

Clinical Presentation: Here we present a 22-year-old woman with a pituitary carcinoma that was immunohistochemically positive for luteinizing hormone and follicle-stimulating hormone at both the primary and metastatic sites.

Role of tfdC(I)D(I)E(I)F(I) and tfdD(II)C(II)E(II)F(II) gene modules in catabolism of 3-chlorobenzoate by Ralstonia eutropha JMP134(pJP4).

The enzymes chlorocatechol-1,2-dioxygenase, chloromuconate cycloisomerase, dienelactone hydrolase, and maleylacetate reductase allow Ralstonia eutropha JMP134(pJP4) to degrade chlorocatechols formed during growth in 2,4-dichlorophenoxyacetate or 3-chlorobenzoate (3-CB). There are two gene modules located in plasmid pJP4, tfdC(I)D(I)E(I)F(I) (module I) and tfdD(II)C(II)E(II)F(II) (module II), putatively encoding these enzymes. To assess the role of both tfd modules in the degradation of chloroaromatics, each module was cloned into the medium-copy-number plasmid vector pBBR1MCS-2 under the control of the tfdR regulatory gene.

Effect of biocompatibility of hemodialysis membranes on serum albumin levels.

Hypoalbuminemia in end-stage renal disease is a marker of high morbidity and mortality. In some patients, the cause of low serum albumin levels is easily identified and therefore treatable, but in many patients, the cause is not clear. We studied the effect of changing the dialysis membrane from a bioincompatible to a biocompatible membrane on serum albumin level.

A consortium-based research education program for residents.

With growing pressures to consolidate and reorganize health care delivery systems, graduate medical education (GME) consortia can draw faculty from affiliated members to assemble educational programs. The authors report on consortium-based research education seminars of a quality that many residency programs would be unable to develop and support on their own. Drawing a diverse faculty from consortium members and area universities, the OHEP Center for Medical Education's annual Research Workshop Series focuses on the design of research projects; data analysis and hypothesis testing; and written and oral presentation of scientific research.

Percutaneous retrogasserian glycerol rhizolysis for treatment of chronic intractable cluster headaches: long-term results.

Objective: To analyze the long-term effectiveness and safety of percutaneous retrogasserian glycerol rhizolysis (PRGR) in the treatment of medically refractive chronic cluster headache (CH). The current mainstay of surgical intervention for these patients is percutaneous radiofrequency retrogasserian rhizotomy (PRFR). However, when performed for V1 distribution pathology, PRFR can lead to corneal anesthesia, which places the patient at risk for future visual loss.

Dehydroepiandrosterone and exercise in golden hamsters.

Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) are adrenal androgens that have been associated with a sense of well-being in humans. We describe two experiments done to test the hypothesis that an increase in DHEA or DHEAS secretion is associated with the inclination to exercise using a hamster model. In the first experiment, morning blood samples were obtained from adult male golden hamsters at various intervals after being placed in cages with (EX group) or without (SED group) access to running wheels.

Management of intracranial meningiomas secondarily involving the infratemporal fossa: radiographic characteristics, pattern of tumor invasion, and surgical implications.

Objective: Intracranial meningiomas extending into the infratemporal fossa (ITF) are uncommon. This series describes the radiographic characteristics, histological pattern of invasion, and implications for surgical treatment of intracranial meningiomas.

Methods: Nine patients (median age, 52 yr) underwent resection of a transcranial meningioma extending into the ITF.

Bacteria designed for bioremediation.

Although many environmental pollutants are efficiently degraded by microorganisms, others persist and constitute a severe health hazard. In some instances, persistence is a consequence of the inadequate catabolic potential of the available microorganisms. Gene technology, combined with a solid knowledge of catabolic pathways and microbial physiology, enables the experimental evolution of new or improved catabolic activities for such pollutants.

Hyperostosis associated with meningioma of the cranial base: secondary changes or tumor invasion.

Objective: Hyperostosis associated with intracranial meningiomas is a well-described entity. The cause, management, and prognosis of these bony changes have long been a point of controversy. Some authors have postulated that hyperostotic changes are secondary to the formation of the tumor and do not constitute invasion of the tumor into the bone.

NahW, a novel, inducible salicylate hydroxylase involved in mineralization of naphthalene by Pseudomonas stutzeri AN10.

Two genes, nahG and nahW, encoding two independent salicylate 1-hydroxylases have been identified in the naphthalene-degrading strain Pseudomonas stutzeri AN10. While nahG resides in the same transcriptional unit as the meta-cleavage pathway genes, forming the naphthalene degradation lower pathway, nahW is situated outside but in close proximity to this transcriptional unit. The nahG and nahW genes of P.

Initial reactions in the biodegradation of 1-chloro-4-nitrobenzene by a newly isolated bacterium, strain LW1.

Bacterial strain LW1, which belongs to the family Comamonadaceae, utilizes 1-chloro-4-nitrobenzene (1C4NB) as a sole source of carbon, nitrogen, and energy. Suspensions of 1C4NB-grown cells removed 1C4NB from culture fluids, and there was a concomitant release of ammonia and chloride. Under anaerobic conditions LW1 transformed 1C4NB into a product which was identified as 2-amino-5-chlorophenol by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry.

Neural pathway from the olfactory bulbs regulating tonic gonadotropin secretion.

Removal of the olfactory bulbs of male golden hamsters results in a marked increase in tonic gonadotropin, prolactin and testosterone secretion which counteracts inhibitory effects of manipulations such as maintenance on short photoperiod, food restriction or treatment with gonadal steroids. The bulbectomy-induced increase in hormone secretion is interpreted to reflect a tonic inhibitory influence of the olfactory bulbs. This inhibition is not dependent upon chemosensory stimulation and may be mediated by olfactory bulb fibers projecting through the lateral olfactory tract to or through the olfactory tubercle.

Does exercise affect female hamster gonadotropins by reducing estradiol negative feedback?

Exercise stimulates reproductive function in hamsters exposed to short-day photoperiod (SDP) in contrast to its inhibitory effects in women and rats. SDP inhibits hamster reproduction in part by increasing the sensitivity of the hypothalamo-pituitary-gonadal axis (HPGA) to the negative feedback of gonadal steroids. To determine whether EX facilitates reproduction in female hamsters by affecting this mechanism, we examined the influence of estradiol (E2) on basal LH and FSH concentrations in exercising and sedentary hamsters maintained on long-day photoperiod (LD 14:10, LDP) or SDP (LD 8:16).

Genetic and biochemical analyses of the tec operon suggest a route for evolution of chlorobenzene degradation genes.

The TecA broad-spectrum chlorobenzene dioxygenase of Burkholderia sp. strain PS12 catalyzes the first step in the mineralization of 1,2,4, 5-tetrachlorobenzene. The catabolic genes were localized on a small plasmid that belongs to the IncPbeta incompatibility group.

3-nitroadipate, a metabolic intermediate for mineralization of 2, 4-dinitrophenol by a new strain of a Rhodococcus species.

The bacterial strain RB1 has been isolated by enrichment cultivation with 2,4-dinitrophenol as the sole nitrogen, carbon, and energy source and characterized, on the basis of 16S rRNA gene sequence comparison, as a Rhodococcus species closely related to Rhodococcus opacus. Rhodococcus sp. strain RB1 degrades 2,4-dinitrophenol, releasing the two nitro groups from the compound as nitrite.

Identification of chlorobenzene dioxygenase sequence elements involved in dechlorination of 1,2,4,5-tetrachlorobenzene.

The TecA chlorobenzene dioxygenase and the TodCBA toluene dioxygenase exhibit substantial sequence similarity yet have different substrate specificities. Escherichia coli cells producing recombinant TecA enzyme dioxygenate and simultaneously eliminate a halogen substituent from 1,2,4,5-tetrachlorobenzene but show no activity toward benzene, whereas those producing TodCBA dioxygenate benzene but not tetrachlorobenzene. A hybrid TecA dioxygenase variant containing the large alpha-subunit of the TodCBA dioxygenase exhibited a TodCBA dioxygenase specificity.

A new intermediate in the mineralization of 3,4-dichloroaniline by the white rot fungus Phanerochaete chrysosporium.

Phanerochaete chrysosporium ATCC 34541 has been reported to be unable to mineralize 3,4-dichloroaniline (DCA). However, high mineralization is now shown to occur when a fermentation temperature of 37 degrees and gassing with oxygen are used. Mineralization did not correlate with lignin peroxidase activity.

Biochemical and genetic characterization of a gentisate 1, 2-dioxygenase from Sphingomonas sp. strain RW5.

A 4,103-bp long DNA fragment containing the structural gene of a gentisate 1,2-dioxygenase (EC 1.13.11.

Removal of the olfactory bulbs delays photic reentrainment of circadian activity rhythms and modifies the reproductive axis in male Octodon degus.

The diurnal rodent, Octodon degus, exhibits robust sex differences in several circadian measures, including circadian period (tau) and reentrainment rates to photic and nonphotic (social) zeitgebers. The neural substrates underlying such physiological differences remain unknown. In female degus, olfactory bulbectomies (BX) inhibit socially-facilitated reentrainment, but do not alter photic reentrainment, entrained measures, or tau in constant darkness (DD).

Characterization of a gene cluster from Ralstonia eutropha JMP134 encoding metabolism of 4-methylmuconolactone.

A 2,585 bp chromosomal DNA segment of Ralstonia eutropha JMP134 (formerly: Alcaligenes eutrophus JMP134) which contains a gene cluster encoding part of the modified ortho-cleavage pathway encodes a putative transport protein for 4-methylmuconolactone, a novel 4-methylmuconolactone methylisomerase and methylmuconolactone isomerase. The putative 4-methylmuconolactone transporter, a protein with a calculated molecular mass of 45.8 kDa, exhibits sequence homology to other members of the major superfamily of transmembrane facilitators and shows the common structural motif of 12 transmembrane-spanning alpha-helical segments and the hallmark amino acid motif characteristic of the superfamily.

Detoxification of protoanemonin by dienelactone hydrolase.

Protoanemonin is a toxic metabolite which may be formed during the degradation of some chloroaromatic compounds, such as polychlorinated biphenyls, by natural microbial consortia. We show here that protoanemonin can be transformed by dienelactone hydrolase of Pseudomonas sp. strain B13 to cis-acetylacrylate.

Role of surgery in the treatment of brain metastases in patients with breast cancer.

Background: Patients whose brain metastases from breast cancer are treated nonsurgically have a median length of survival ranging from 2.5 to 7.5 months, and a median time to recurrence ranging from 2 to 5 months.

Genetic and biochemical characterization of the broad spectrum chlorobenzene dioxygenase from Burkholderia sp. strain PS12--dechlorination of 1,2,4,5-tetrachlorobenzene.

The bacterium, Burkholderia (previously Pseudomonas) sp. strain PS12, reported earlier to degrade 1,2,4-trichlorobenzene is shown here to utilize also 1,2,4,5-tetrachlorobenzene (Cl4-benzene) as a growth substrate. To investigate the possibility that this organism attacks Cl4-benzene with a chlorobenzene dioxygenase which concomitantly causes dehalogenation, and to analyze the substrate range of the initial enzyme, a 5503-bp DNA fragment from PS12, exhibiting high similarity to genes coding for class IIB dioxygenases, was cloned and expressed in Escherichia coli.

Evidence for an isomeric muconolactone isomerase involved in the metabolism of 4-methylmuconolactone by Alcaligenes eutrophus JMP134.

An enzyme specifically induced during 4-methylmuconolactone metabolism by Alcaligenes eutrophus JMP 134 and that exhibited muconolactone isomerizing activity was purified to homogeneity. The enzyme, involved in the isomerization of 3-methylmuconolactone had a high degree of sequence similarity with muconolactone isomerase of Alcaligenes eutrophus JMP 134 and other previously described muconolactone isomerases of the 3-oxoadipate pathway. Kinetic analysis showed that the enzyme has a substrate spectrum and a reaction mechanism similar to those of the muconolactone isomerase, but that it has distinct kinetic properties.