Neural subspaces of imagined movements in parietal cortex remain stable over several years in humans.

A crucial goal in brain-machine interfacing is long-term stability of neural decoding performance, ideally without regular retraining. Here we demonstrate stable neural decoding over several years in two human participants, achieved by latent subspace alignment of multi-unit intracortical recordings in posterior parietal cortex. These results can be practically applied to significantly expand the longevity and generalizability of future movement decoding devices.

Bactericidal activity of the nitroimidazopyran PA-824 in a murine model of tuberculosis.

The nitroimidazopyran PA-824 has potent in vitro activity against Mycobacterium tuberculosis, a narrow spectrum of activity limited primarily to the M. tuberculosis complex, and no demonstrable cross-resistance to a variety of antituberculosis drugs. In a series of experiments, we sequentially characterized the activity of PA-824 in an experimental murine model of tuberculosis. The minimal effective dose was 12.5 mg/kg of body weight/day. The minimal bactericidal dose (MBD) was 100 mg/kg/day. When PA-824 was used as monotherapy at the MBD, it exhibited promising bactericidal activity during the initial intensive phase of therapy that was similar to that of the equipotent dose of isoniazid in humans. In combination with isoniazid, PA-824 prevented the selection of isoniazid-resistant mutants. Perhaps more importantly, PA-824 also demonstrated potent activity during the continuation phase of therapy, during which it targeted bacilli that had persisted through an initial 2-month intensive phase of treatment with rifampin, isoniazid, and pyrazinamide. Together, these data strongly support further evaluation of PA-824 in combination with first- or second-line antituberculosis drugs to determine its potential contribution to the treatment of drug-susceptible or multidrug-resistant tuberculosis, respectively.

The chemical accident risk assessment thesaurus: a tool for analyzing and comparing diverse risk assessment processes and definitions.

The Chemical Accident Risk Assessment Thesaurus (CARAT) is a database of the laws, regulations, guidance documents, and definitions of terms related to the risk assessment of accidental releases of chemicals from fixed installations. The database also contains information on the application of risk assessment methodologies to specific examples of potential chemical releases. The Organization for Economic Cooperation and Development urged the development of the Thesaurus to improve the communication among the member countries about the risk assessment of hazardous installations. The difficulty of communication is based in large part on the fact that certain "terms of art" have different meanings in different countries and cultures, or that different terms of art are used to address the same concept. The CARAT is designed to circumvent these difficulties, and is especially useful as a tool to analyze the definitions of terms related to risk assessment. Entries into the CARAT contain information from various international, national, and regional agencies that relate to risk assessment processes and definitions focused on accidental chemical releases. The entire system is accessible via the Internet. Retrieval of information from the CARAT is facilitated by five different searching tools: two of them are designed to search the CARAT for its entries. One facility is designed to search for laws and regulations, specific risk assessment cases (SRA), and risk assessment guidance documents (RAG) related to chemical accidents. The second search facility deals with entries of definitions. The design of the CARAT is ideally suited to capture the sense of definitions that are expressed as either a procedural definition (an "operation on a concept") or a conceptual definitions (just the "concept"). A powerful third query tool is the "Comparison" facility. This query tool allows the user to compare the details CARAT entries of laws and regulations, SRA, RAG, or definitions, in any combination. The remaining two tools can perform searches by identifying entries that contain either certain combinations of hierarchical or descriptor details. Both types can be conducted in Boolean "and/or" mode.

Utilizing third-party inspections for preventing major chemical accidents.

This paper proposes using certified third parties, coupled with Model Risk Management Programs (Model RMPs), to implement EPA's Proposed Rule on the prevention of chemical accidental releases. We concentrate on the insurance aspects of this third-party approach and show that it could enable insurers to more cost-effectively provide coverage against the risks of chemical accidental releases. The third-party approach may also signal the facility's safety and reduce the enforcement costs of regulations.

DAX1 mutations map to putative structural domains in a deduced three-dimensional model.

The DAX1 protein is an orphan nuclear hormone receptor based on sequence similarity in the putative ligand-binding domain (LBD). DAX1 mutations result in X-linked adrenal hypoplasia congenita (AHC). Our objective was to identify DAX1 mutations in a series of families, to determine the types of mutations resulting in AHC and to locate single-amino-acid changes in a DAX1 structural model. The 14 new mutations identified among our 17 families with AHC brought the total number of families with AHC to 48 and the number of reported mutations to 42; 1 family showed gonadal mosaicism. These mutations included 23 frameshift, 12 nonsense, and six missense mutations and one single-codon deletion. We mapped the seven single-amino-acid changes to a homology model constructed by use of the three-dimensional crystal structures of the thyroid-hormone receptor and retinoid X receptor alpha. All single-amino-acid changes mapped to the C-terminal half of the DAX1 protein, in the conserved hydrophobic core of the putative LBD, and none affected residues expected to interact directly with a ligand. We conclude that most genetic alterations in DAX1 are frameshift or nonsense mutations and speculate that the codon deletion and missense mutations give insight into the structure and function of DAX1.

Congenital hypothyroidism due to mutations in the sodium/iodide symporter. Identification of a nonsense mutation producing a downstream cryptic 3' splice site.

A 12-yr-old hypothyroid girl was diagnosed at birth as athyreotic because her thyroid gland could not be visualized by isotope scanning. Goiter development due to incomplete thyrotropin suppression, a thyroidal radioiodide uptake of < 1%, and a low saliva to plasma ratio of 2.5 suggested iodide (I-) transport defect. mRNA isolated from her thyroid gland and injected into Xenopus oocytes failed to increase I- transport. Sequencing of the entire Na+/I- symporter (NIS) cDNA revealed a C to G transversion of nucleotide (nt) 1146 in exon 6, resulting in a Gln 267 (CAG) to Glu (GAG) substitution. This missense mutation produces an NIS with undetectable I- transport activity when expressed in COS-7 cells. Although only this missense mutation was identified in thyroid and lymphocyte cDNA, genotyping revealed that the proposita and her unaffected brother and father were heterozygous for this mutation. However, amplification of cDNA with a primer specific for the wild-type nt 1146 yielded a sequence lacking 67 nt. Genomic DNA showed a C to G transversion of nt 1940, producing a stop codon as well as a new downstream cryptic 3' splice acceptor site in exon 13, responsible for the 67 nt deletion, frameshift, and premature stop predicting an NIS lacking 129 carboxy-terminal amino acids. This mutation was inherited from the mother and present in the unaffected sister. Thus, although the proposita is a compound heterozygote, because of the very low expression (< 2.5%) of one mutant allele, she is functionally hemizygous for an NIS without detectable bioactivity.

Central hypothyroidism reveals compound heterozygous mutations in the Pit-1 gene.

Mutations in the gene encoding the Pit-1 transcriptional activator interfere with the embryologic determination and ultimate functions of anterior pituitary cells that produce growth hormone (GH), prolactin (Prl) and thyroid-stimulating hormone (TSH). Central hypothyroidism is often the presenting feature of combined pituitary hormone deficiency (CPHD), but it is not detected in screening programs that rely upon elevation of TSH. We report a child whose hypothyroidism was recognized clinically at age 6 weeks, and subsequently found to have GH and Prl as well as TSH deficiency. With thyroxine and GH replacement he has reached the 70th percentile for height and has normal intelligence. Molecular analysis of genomic DNA for Pit-1 revealed the presence of compound heterozygous recessive mutations: a nonsense mutation in codon 172 and a novel missense mutation substituting glycine for glutamate at codon 174. This case is the first demonstration of CPHD due to compound heterozygous Pit-1 point mutations, as most reported cases of the CPHD phenotype involve either the dominant negative R271W allele or homozygosity for recessive Pit-1 mutations. Therefore, in cases of CPHD, the possibilities of compound heterozygosity for two different Pit-1 mutations, or homozygosity for mutations in the epigenetic gene, Prop-1, should be considered.

Management of hypertension and its sequelae with ACE inhibitors: biochemical, pharmacological and clinical aspects.

ACE inhibitors are a widely prescribed class of drug for the management of hypertension. Their therapeutic role in the treatment of heart failure, diabetic nephropathy and post myocardial infarction with left ventricular dysfunction is steadily increasing. Although ACE inhibitors have a similar mechanism of action--namely, inhibition of circulatory ACE, thereby decreasing the formation of angiotensin II--individual members differ in their physicochemical properties, enzyme-binding kinetics, pharmacokinetic profile, organ-specific affinity and selectivity, as well as in their bradykinin potentiating effect. These factors play an important part in influencing the pharmacological profile of an agent and its clinical efficacy, especially in the treatment of hypertension. It is therefore prudent to take into account the existing pharmacological and clinically relevant differences between the individual members of this drug class before making the decision to select a particular ACE inhibitor for the long-term management of arterial hypertension.

Public health and the safety of milk and milk products from sheep and goats.

Goats and sheep rank third and fourth in terms of global milk production from different species, but unlike cow milk, which has stringent hygiene and quality regulations, microbiological standards for the production and distribution of goat milk and sheep milk are more relaxed. Difficulties in managing the sanitary quality of sheep and goat milk derive from a series of factors including the low level of production per head, the milking system, the difficulty involved in machine milking, the conditions under which the herds or flocks are raised, adverse climatic conditions and the spread of production over a wide geographic area. Fresh goat milk is consumed by infants and others with allergies to cow milk and is also used for on-farm manufactured cheese, with or without thermal treatment. The high fat content and peculiar taste of cheeses made from ewe milk are also very popular. These cheese varieties, which are mostly still of 'artisan-type', are not covered by regulatory definitions and the dispute over the use of raw versus pasteurised milk is still alive. However, in documented intoxications recorded after the consumption of cheese, there has always been evidence of incorrect temperature control during pasteurisation, the deliberate addition of raw milk, or contamination during storage. Compositional differences between the milk from cows, ewes and goats (chemical composition of lipids, phosphatase level, freezing point, natural bacterial inhibitor levels, somatic cell count, etc.) preclude the nondiscriminatory use of bovine standards for regulatory purposes. Quality standards adjusted for the specifics of ewe/goat milk should be considered. The production of safe cheese is linked to a series of conditions which ensure consumer health, primarily pasteurisation. In the absence of pasteurisation, all cheeses made from raw milk should be subjected to strict periodic controls.

Response to challenge with gonadotropin-releasing hormone agonist in a mother and her two sons with a constitutively activating mutation of the luteinizing hormone receptor--a clinical research center study.

The pituitary-gonadal axis was evaluated in a mother after two of her sons with familial male-limited pseudoprecocious puberty were found to have a constitutively activating mutation of the LH receptor (LHR). Genotyping demonstrated that all showed a mutation in one of the two alleles, a substitution of Gly for Asp578 in the sixth transmembrane segment of the LHR. Ovarian function was normal in the 36-yr-old mother as assessed by LH dynamics and FSH and androgen levels throughout the menstrual cycle. Hormonal responses to acute GnRH agonist (nafarelin) challenge, chronic GnRH agonist administration, and dexamethasone were also normal. Studies of the boys upon presentation at 2.4 and 3.5 yr of age revealed that acute LH responses to nafarelin were in the hypogonadotropic range, and the FSH responses were prepubertal despite the presence of late pubertal testosterone blood levels. Upon the inception of true puberty at 11 yr of age in the older brother, gonadotropin responses normalized for the state of development. The data show that this activating LHR mutation does not cause functional ovarian hyperandrogenism and causes only incomplete pubertal activation of Leydig cells. The results are compatible with relatively low constitutive activity associated with this structural abnormality of LHR.

Alkaline phosphatase activity in Penicillium roqueforti and in blue-veined cheeses.

The Penicillium roqueforti mold exhibits alkaline phosphatase activity. Therefore, blue mold-ripened cheeses made from properly pasteurized milk test positive for phosphatase. Because microbial phosphatases are considered to be more resistant to heat than is milk phosphatase, a statutory control test recommends the repasteurization of cheese at 66 degrees C for 30 min to inactivate selectively the native milk enzyme. However, because of thermal lability of Penicillium roqueforti phosphatase, this control test leads to confusion of the fungal enzyme with native milk alkaline phosphatase and does not confirm whether the milk used to make cheese has been pasteurized.

Virus inactivation in red cell concentrates by photosensitization with phthalocyanines: protection of red cells but not of vesicular stomatitis virus with a water-soluble analogue of vitamin E.

BACKGROUND: Photodynamic treatment of red cells (RBCs) with phthalocyanines and red light inactivates lipid-enveloped viruses, such as vesicular stomatitis virus (VSV) and human immunodeficiency virus. To protect RBCs from photodynamic damage, type I free radical quenchers, such as mannitol, which did not affect virus inactivation, were added. STUDY DESIGN AND METHODS: Aluminum phthalocyanine tetrasulfonate (AIPcS4) was found to inactivate VSV at a rate one-fourth that of the silicon phthalocyanines (Pc 4 and Pc 5). However, the latter also caused more RBC damage. To protect RBCs against this photodynamic damage, Trolox, a water-soluble vitamin E analogue, was used. RBC damage was measured as potassium leakage or hemolysis during storage after treatment. In addition, reduction in negative surface charge on RBCs was measured immediately after treatment, and the effect of Trolox on VSV inactivation in RBCs was evaluated. RESULTS: Trolox at a concentration of 5 mM was found to reduce potassium leakage during storage after Pc 4 and AIPcS4 photodynamic treatment of RBCs. Hemolysis during storage of RBC concentrates treated with Pc 4 or Pc 5 was drastically reduced by the addition of 5 mM Trolox prior to light exposure. At the same concentration, Trolox inhibited the reduction of negative surface charges on RBCs following Pc 4 and Pc 5 photodynamic treatment. Under these conditions, VSV inactivation by photodynamic treatment with all phthalocyanines was not affected by Trolox. In aqueous solution, Trolox formed a complex with AIPcS4, thus quenching the excited triplet state of AIPcS4 at a constant rate of 8.8 x 10(6) per M per second. CONCLUSION: These findings indicate that Trolox protects RBCs from phthalocyanine-photosensitized damage without affecting virus kill. The addition of Trolox would be beneficial for improving the quality of RBCs subjected to photodynamic treatment.

Role of oxygen in the phototoxicity of phthalocyanines.

The presence of molecular oxygen is a determinant in the phototoxicity of phthalocyanines, and photosensitized oxidation is the accepted chemical mechanism for photo-dynamic action. However, it is difficult to establish whether the process is initiated by a type I electron transfer, or by a type II energy transfer reaction to form singlet oxygen. Usually, the involvement of singlet oxygen in photodamage has been indicated by the inhibition of the biological effect by a competitive physical or chemical singlet oxygen quencher, or by a rate increase in D2O, in which singlet oxygen has a longer lifetime than in H2O. Unfortunately, these techniques are not completely specific for singlet oxygen. Moreover, thermodynamic considerations suggest that photoinduced electron abstraction from appropriate biomaterials could compete with singlet oxygen production under in vivo conditions. This likely source of one electron-oxidized primary radicals, which can provide the precursors of the oxidative damage in phthalocyanine photosensitization, suggests the possibility of modulated toxicity by interaction with chemical additives. Examples of such additives recently studied are ascorbate, tocopherol and quercetin, all of which are natural antioxidants.

Feminizing Sertoli cell tumors in boys with Peutz-Jeghers syndrome.

We report the pathology findings in two cases of multicentric Sertoli cell testicular tumors in two young boys with probable Peutz-Jeghers syndrome. Four cases of such tumors occurring in boys with Peutz-Jeghers syndrome were previously reported. Each of the two boys reported in this paper had prominent gynecomastia, rapid growth, and advanced bone age. Serum levels of estradiol were markedly elevated. Anti-müllerian hormone was measured in the serum of one of the boys and was in the normal range for age. Bilateral orchiectomy was performed in each case because the neoplastic growth would most likely result in sterility, and curtailment of height potential was threatened from continued elevation of estradiol levels. Microscopically, greatly enlarged seminiferous tubules packed with ovoid Sertoli-like cells were present. Prominent eosinophilic basement membrane surrounded the tubules and intersected between the cells, forming hyalinized ovoid globules and microcalcifications. Ultrastructure revealed lamination of basement membranes surrounding adjacent cells, ovoid cells with abundant cytoplasm, and limited smooth endoplasmic reticulum. Studies of testicular tumor tissue from both cases revealed increased transcription of the aromatase cytochrome P450 gene using promoter II, the promoter directing aromatase expression in the normal ovary and testis. The levels of transcripts were comparable to corpus luteum, thus resulting in increased estrogen synthesis. Transcripts specific for placental-type aromatase promoters (I.1 and I.2) were not detected in significant levels in these tumors.

Ovarian hyperandrogynism as a result of congenital adrenal virilizing disorders: evidence for perinatal masculinization of neuroendocrine function in women.

Women with congenital adrenal hyperplasia due to 21-hydroxylase deficiency often have a polycystic ovary-like syndrome, consisting of hyperandrogynism, infertility, menstrual irregularities, and elevated LH levels. This is generally considered secondary to poor control of the congenital adrenal hyperplasia. However, our experience led us to suspect that ovarian hyperandrogenism occurs even when congenital adrenal hyperplasia is well controlled on glucocorticoid therapy. Therefore, we tested the hypothesis that congenital adrenal virilizing disorders result in ovarian hyperandrogenism. We studied eight women with congenital adrenal virilizing disorders, seven with well controlled classic 21-hydroxylase deficiency and one with congenital virilizing adrenal carcinoma removed at 1.7 yr of age. We also studied six women with late-onset 21-hydroxylase deficiency, without signs of congenital virilization. An ovarian source of androgens was assessed after suppressing adrenal function with dexamethasone and then testing pituitary-ovarian function by a GnRH agonist (nafarelin) test. Five women with congenital adrenal virilizing disorders (four with classic 21-hydroxylase deficiency and one with congenital virilizing adrenal carcinoma) and one women with late-onset 21-hydroxylase deficiency had ovarian hyperandrogenism as determined by subnormal suppression of free testosterone after dexamethasone and/or by increased 17-hydroxyprogesterone response to nafarelin while on dexamethasone. All women with congenital adrenal virilization and ovarian hyperandrogenism had elevated LH levels after dexamethasone or elevated early LH response to nafarelin, which suggests that LH excess is the cause of their ovarian hyperandrogenism. This was not the case for the late-onset 21-hydroxylase-deficient woman. Our data are compatible with the hypothesis that congenital adrenal virilization programs the hypothalamic-pituitary axis for hypersecretion of LH at puberty. This is postulated to frequently cause ovarian hyperandrogenism even when adrenal androgen excess is subsequently controlled by glucocorticoid therapy.

The photochemical properties of fluoroaluminum phthalocyanine.

Fluoride is known to inhibit the photodynamic activity of aluminium phthalocyanine in a variety of biological systems. In order to gain insight into this phenomenon, the effect of fluoride on the photophysical properties of free and albumin-bound chloroaluminum phthalocyanine sulfonate (AlPcSn) were studied. The association constant of NaF with AlPcSn in aqueous solution was measured as 500 +/- 20 M-1. This binding affects the photophysical properties of the dye: the absorption bands in the visible range are blue-shifted by 6-8 nm, and this effect is mirrored in the fluorescence emission spectrum. Human serum albumin significantly quenched the dye fluorescence independent of the presence of fluoride ion. The transient absorption spectrum of the excited dye triplet is unchanged by NaF, but the quantum yield for its generation is increased by 50%, with no decrease in its lifetime. Formation of fluoroaluminum phthalocyanine complexes was also observed in tetrabutylammonium fluoride-assisted solutions in wet acetonitrile. The fluoro-AlPcSn complex is a better photosensitizer for generation of singlet oxygen than the original dye-hydroxyl ion complex, as confirmed using the imidazole-N,N-dimethyl-4-nitrosoaniline method. On the other hand, the fluoro-AlPcSn complex exhibits an intense inhibitory effect on photohemolysis of red blood cells (RBC) even after the cells are washed to remove free dye and fluoride prior to irradiation, indicating that once the dye is attached to the cellular site, the fluoride ligand is no longer prone to displacement (by hydroxyl ion, for example). Nonetheless, it is clear from the spectroscopic data that the new fluoro complex is an efficient sensitizer for photooxidation.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of tissue-specific promoters in the regulation of aromatase cytochrome P450 gene expression in human testicular and ovarian sex cord tumors, as well as in normal fetal and adult gonads.

We have previously demonstrated that the tissue-specific regulation of human aromatase cytochrome P450 (P450arom) gene expression is, in part, the consequence of the use of tissue-specific promoters. Promoter I.1 (PI.1) and PI.2-specific transcripts are expressed in the placenta, whereas promoter II (PII) appears to be the only active promoter in the corpus luteum. Testicular and ovarian sex cord tumors with annular tubules (SCTATs) associated with gynecomastia in prepubertal boys and isosexual precocity in girls with Peutz-Jeghers syndrome (P-JS) have been previously reported. In the present study, we investigated the regulatory elements directing P450arom gene transcription in samples of SCTAT from three prepubertal boys and a girl with P-JS and an ovarian granulosa cell tumor from an adult woman, as well as in healthy fetal and adult testicular and ovarian tissues. Placental tissue was used as a control. Using polymerase chain reaction linked to reverse transcription and northern blotting, we determined the tissue-specific use of various P450arom promoters by analyzing specific 5'-termini from messenger RNA templates. Results indicate a universal gonadal promoter (PII) directs P450arom gene expression in healthy fetal and adult ovaries and testes, as well as in SCTAT of the P-JS and an adult ovarian granulosa cell tumor. These results are interpreted to mean that use of PII in human ovary and testis is preserved from the fetal period into adult life as well as in transformed neoplastic Sertoli and granulosa cells. On the other hand, transcripts from placenta are specific for PI.1 (and to a much lesser extent, PI.2). In SCTAT, immunoreactive P450arom is detected only in the cytoplasm of neoplastic cells, whereas the normal-appearing sex cords do not contain any immunoreactive P450arom. These results further suggest that the markedly increased aromatase expression of these transformed neoplastic cells is not a consequence of using different tissue-specific promoters. Rather it appears to involve activation (or failure of inhibition) of the upstream regulatory elements of the same promoter, which is normally functional in all gonadal tissues, namely the proximal PII.

Surgical and genetic aspects of persistent müllerian duct syndrome.

Persistent müllerian duct syndrome (PMDS) is characterized by the presence of a uterus, cervix, and fallopian tubes in an otherwise normally differentiated 46.XY male. During embryogenesis, regression of müllerian structures in normal males is mediated by antimüllerian hormone (AMH), also called müllerian inhibiting substance (MIS), produced by fetal Sertoli's cells. PMDS has been attributed to deficient AMH activity or to abnormalities in the AMH receptor. The authors report on two patients with PMDS in whom the abnormalities were discovered during surgery for inguinal hernia and cryptorchidism. During the initial operations in each case, testicular biopsies were obtained, and the gonads and müllerian elements were replaced in the pelvis. A second operative procedure, performed several months later, included proximal salpingectomies with dissection of the vasa deferentia on pedicles of myometrium. This permitted excision of the vestigial uterine corpus, leaving a tiny remnant of cervix with the vasa deferentia. The testes were further mobilized so that bilateral orchidopexies could be completed. In the first case, a molecular abnormality was present at position 377 of the first exon of the AMH gene. Thymine replaced cytosine, which altered a CGG arginine codon to a TGG tryptophan codon, rendering the AMH molecule unstable. The molecular abnormality in the first case differs from the first abnormality in AMH reported by Knebelmann et al, thus indicating heterogeneity in this condition. The molecular basis for deficient AMH activity in the second patient has not yet been defined. No molecular abnormalities were found in the exons of this patient's AMH gene.

Use of tissue-specific promoters in the regulation of aromatase cytochrome P450 gene expression in human testicular and ovarian sex cord tumors, as well as in normal fetal and adult gonads.

We have previously demonstrated that the tissue-specific regulation of human aromatase cytochrome P450 (P450arom) gene expression is, in part, the consequence of the use of tissue-specific promoters. Promoter I.1 (PI.1) and PI.2-specific transcripts are expressed in the placenta, whereas promoter II (PII) appears to be the only active promoter in the corpus luteum. Testicular and ovarian sex cord tumors with annular tubules (SCTATs) associated with gynecomastia in prepubertal boys and isosexual precocity in girls with Peutz-Jeghers syndrome (P-JS) have been previously reported. In the present study, we investigated the regulatory elements directing P450arom gene transcription in samples of SCTAT from three prepubertal boys and a girl with P-JS and an ovarian granulosa cell tumor from an adult woman, as well as in healthy fetal and adult testicular and ovarian tissues. Placental tissue was used as a control. Using polymerase chain reaction linked to reverse transcription and northern blotting, we determined the tissue-specific use of various P450arom promoters by analyzing specific 5'-termini from messenger RNA templates. Results indicate a universal gonadal promoter (PII) directs P450arom gene expression in healthy fetal and adult ovaries and testes, as well as in SCTAT of the P-JS and an adult ovarian granulosa cell tumor. These results are interpreted to mean that use of PII in human ovary and testis is preserved from the fetal period into adult life as well as in transformed neoplastic Sertoli and granulosa cells. On the other hand, transcripts from placenta are specific for PI.1 (and to a much lesser extent, PI.2). In SCTAT, immunoreactive P450arom is detected only in the cytoplasm of neoplastic cells, whereas the normal-appearing sex cords do not contain any immunoreactive P450arom. These results further suggest that the markedly increased aromatase expression of these transformed neoplastic cells is not a consequence of using different tissue-specific promoters. Rather it appears to involve activation (or failure of inhibition) of the upstream regulatory elements of the same promoter, which is normally functional in all gonadal tissues, namely the proximal PII.

Inhibition of phthalocyanine-sensitized photohemolysis of human erythrocytes by quercetin.

Photohemolysis of erythrocytes in the presence of aluminum phthalocyanine tetrasulfonate as a sensitizer is inhibited by quercetin. D2O (98.5%) stimulated photohemolysis regardless of quercetin presence, suggesting the participation of singlet oxygen in the process. Since it has been shown that this flavonoid reacts with singlet oxygen, the protective effect might be attributed, at least partially, to its competitive reaction with singlet oxygen. At the molecular level, the alterations of membrane proteins that escort the process of photohemolysis, such as cross-linking of spectrin monomers and of other membrane proteins, were selectively inhibited by quercetin. This effect was qualitatively similar to that induced by NaF, suggesting that quercetin may, like NaF, also inhibit type I photooxidations, which contribute to hemolysis. The lipophilicity of quercetin seems to be an essential factor in the inhibition process; rutin, a water-soluble 3-rutinoside of quercetin, had only a negligible protective effect on photohemolysis.