The history of ultrasound in gynecology 1950-1980

The pioneers of gynecological ultrasound were active from 1950 to 1960. In this period, compound contact scanning was developed. The disciples who followed were responsible for the explosive growth that had occurred by 1975. The indications for diagnostic ultrasound in gynecology were, first, in cystic and solid masses; they increased steadily to include nonpalpable pelvic masses, ascites, ovarian tumors, cervical lesions, early pregnancy, localization of intrauterine devices, cancer, pelvic inflammatory disease and many more. The techniques also evolved from A-mode, through two-dimensional B-mode, grey tones and special probes, to guided procedures. Signs of tissue anomalies and approaches to tissue characterization were explored. Figures were established to demonstrate the usefulness of diagnostic ultrasound in gynecology in numerous clinical conditions. The review ends with some personal recollections of the early workers, a discussion of the contemporary treatment of the safety of the method and notes on some of the first textbooks.

Axonal targeting of agrin in cultured rat dorsal horn neurons

Agrin, a synaptic basal lamina protein synthesized by motoneurons is involved in the aggregation of nicotinic acetylcholine receptors (nAchRs) at the neuromuscular junction. Agrin transcripts are broadly expressed in the central nervous system (CNS) including non-cholinergic regions. This wide distribution of agrin mRNAs raises the question of its function in these areas. To approach this question, we analysed the expression and cellular distribution of agrin in primary cultures of rat embryonic dorsal horn neurons. Polymerase chain reaction analysis demonstrated that the four agrin isoform (B0, B8, B11, B19) mRNAs are expressed as early as 4 days in vitro, before the formation of functional synaptic contacts. Western blots also showed that agrin-like proteins are secreted in conditioned medium from 7 days cultures. We analysed the subcellular distribution of agrin by double immunolabeling and fluorescence microscopy. We found that agrin is synthesized by almost all neurons and was present in the somata and in the axons but not in dendrites within the sensitivity of the detection. This intra-axonal localisation of agrin could only be seen after permeabilization. Furthermore, agrin immunoreactive axons were found adjacent to gephyrin, the postsynaptic glycine receptor-associated protein. Altogether, our results suggest that, as established at the neuromuscular junction, agrin may be involved in pre- to postsynaptic interactions in the central nervous system.

Evidence that residues exposed on the three-fold channels have active roles in the mechanism of ferritin iron incorporation

Iron is thought to enter the ferritin cavity via the three-fold channel, which is lined in its narrowest part by the residues Asp-131 and Glu-134. We describe here variants of human ferritins with active and inactive ferroxidase centres having Asp-131 and Glu-134 substituted with Ala and Ala or with Ile and Phe respectively. The two types of substitution had similar effects on ferritin functionality: (i) they decreased the amount of iron incorporated from Fe(II) solutions and decreased ferroxidase activity by about 50%; (ii) they inhibited iron incorporation from Fe(III) citrate in the presence of ascorbate; (iii) they resulted in loss of Fe and Tb binding sites; and (iv) they resulted in a marked decrease in the inhibition of iron oxidation by Tb (but not by Zn). In addition, it was found that substitution with Ala of Cys-130 and His-118, both of which face the three-fold channel, decreased the capacity of H-ferritin to bind terbium and to incorporate iron from Fe(III) citrate in the presence of ascorbate. The results indicate that: (i) in three-fold channels are the major sites of iron transfer into the cavity of H- and L-ferritins; (ii) at least two metal binding sites are located on the channels which play an active role in capturing and transferring iron into the cavity; and (iii) the permeability of the channel is apparently not affected by the hydrophilicity of its narrowest part. In addition, it is proposed that iron incorporation from Fe(III) citrate complexes in the presence of ascorbate is a reliable, and possibly more physiological, approach to the study of ferritin functionality.

Evidence that the specificity of iron incorporation into homopolymers of human ferritin L- and H-chains is conferred by the nucleation and ferroxidase centres

Mammalian ferritins are iron-storage proteins made of 24 subunits of two types: the H- and L-chains. L-chains, in contrast with H-chains, lack detectable ferroxidase activity. When ferritins were subjected to iron loading in vitro with increments near the saturation limit of 4000 Fe atoms per molecule, the homopolymers of human H-chains formed insoluble aggregates, caused by non-specific iron hydrolysis, whereas the homopolymers of L-chains remained soluble and incorporated most of the available iron. To analyse the molecular reasons for the difference, Glu-57 and Glu-60, which are conserved and exposed on the cavity of L-chains, were substituted with His, as in H-chains. The double substitution made the L-homopolymers as sensitive as the H-homopolymers to the iron-induced aggregation, whereas the opposite substitution in the H-chain increased homopolymer resistance to the aggregation only marginally. Millimolar concentrations of citrate and phosphate increased iron incorporation in H-homopolymers by reducing non-specific iron hydrolysis, but inhibited that in L-homopolymers by sequestering available iron. The data indicate that the specific iron incorporation into L-homopolymers is mainly due to the iron-nucleation capacity of Glu-57, Glu-60 and other carboxyl groups exposed on the cavity; in contrast, the specificity of iron incorporation into H-homopolymers is related to its ferroxidase activity, which determines rapid Fe(III) accumulation inside the cavity. The finding that ferroxidase centres are essential for the incorporation of iron in the presence of likely candidates of cellular iron transport, such as phosphate and citrate, confirms their importance in ferritin function in vivo.

Tumor-cell vaccination induces tumor dormancy in a murine model of B-cell leukemia/lymphoma (BCL1)

Immunity to murine B-cell leukemia/lymphoma (BCL1) induced by multiple injections with irradiated tumor cells, prevented leukemia development in primary and adoptive transfer recipients despite long-lasting persistence of residual tumor cells. Detection of dormant BCL1 cells was carried out by PCR analysis using the VH-rearranged DNA sequence as a BCL1 clonal marker. Dormant tumor cells were detected > 250 days following immunity induction in 40% of spleens from healthy immune mice having no detectable symptoms of disease. Tumor dormancy was not abrogated by adoptive transfer of BCL1-containing splenocytes into syngeneic recipients, indicating that cell-mediated anti-tumor immunity contributes to maintenance of the tumor dormant state and prevents renewed tumor-cell growth. Splenocytes but not sera from immune mice conferred specific radiosensitive protection from a lethal dose of BCL1 cells included in cell mixtures transferred to secondary recipients. A therapeutic effect of transferred immune splenocytes was shown in BCL1-bearing mice, which remained disease-free for > 200 days after inoculation; nevertheless, dormant BCL1 cells were detected by PCR analysis in some of the surviving mice. Our results suggest that an efficient tumor-cell vaccine can lead to induction of tumor dormancy that can be maintained by a cell-derived mechanism for a long period of time.

Corticosteroids reduce regenerative repair of epithelium in experimental gastric ulcers

The association between corticosteroid treatment and gastric ulcer healing is controversial. The effects of corticosteroids on experimental ulcer healing in the rat were studied and the effect of coadministration of a prostaglandin E1 analogue was determined. Forty male adult rats were divided into five groups and pretreated for 10 days as follows: (a) control, (b) prednisolone (10 mg/kg), (c) prednisolone and misoprostol (300 micrograms/kg), (d) misoprostol, and (e) indomethacin (2 mg/kg) Gastric ulcer was induced by applying a cryoprobe to the serosal surface of the stomach. Healing was assessed by determining the ulcer size at three and six days. Mucosal regenerative activity at the ulcer edge was assessed by quantitating DNA synthesis in cells by immunohistochemical techniques using monoclonal antibodies to detect expression of proliferating cell nuclear antigen (PCNA) and incorporated 5-bromo-5-iododeoxyuridine (BrdU). Compared with control rats, the rate of healing and the mucosal regenerative activity were significantly reduced in rats treated with prednisolone and indomethacin (p < 0.05). Coadministration of misoprostol and corticosteroids reversed the delay in healing and the reduction in mucosal regeneration induced by corticosteroids alone. With misoprostol alone, the ulcer size and the number of epithelial cells that actively synthesised DNA did not differ from control animals. A comparison between the two immunohistochemical markers of cell proliferation showed a highly significant correlation between the two techniques (r = 0.64, p < 0.005), indicating that the simpler PCNA technique should prove valuable in assessing regeneration in experimental ulcer disease.

Induction of tumor immunity by intact irradiated leukemic B cells (BCL1) bearing a tumor-associated cell-surface idiotype and the costimulatory B7 molecule

The idioptypic (Id) determinant of immunoglobulin expressed on the cell surface of malignant B cells represents a prototypical tumor-associated antigen (TAA), which has been used in a purified soluble form for active immunization in experimental tumor models and human hematological malignancies. Using a spontaneous transplantable murine model of B cell leukemia/lymphoma (BCL1), we have demonstrated the expression of the B7 costimulatory molecules in addition to the previously described Id determinant and class II major histocompatibility antigens. Intact irradiated BCL1 cells bearing these distinct determinants induced long lasting antitumor immunity in naive syngeneic mice. Induction was dose-dependent and most effective when three doses of 30 x 10(6) intact irradiated BCL1 cells were given at intervals of 7-10 days. The induced immunity protected 96% of 28 mice inoculated with a lethal dose of 10(5)-10(6) nonirradiated BCL1 cells and 85% of 27 mice given a second challenge, whereas control mice died on day 20 after inoculation with 10(6) BCL1 cells. Adoptive transfer of splenocytes derived from immune mice did not induce leukemia in syngeneic recipients. Such splenocytes, harvested more than 365 days following immunization and administered together with fresh BCL1 cells to adoptive recipients, were able to confer protection for 90 days, even following a second challenge given 104 days after the first one. BCL1 immune splenocytes transferred into BCL1-bearing mice exerted a therapeutic effect, preventing leukemia onset for at least 180 days. Our results demonstrate the ability of tumor cells to trigger effective anti-tumor immunity. These findings could ultimately be applied to the prevention of tumor relapse in treatment of hematological and other malignancies expressing TAA, class II MHC antigen and costimulatory molecules.

End-result of routine ultrasound screening for congenital anomalies: the Belgian Multicentric Study 1984-92

Five ultrasound laboratories from Obstetrics and Gynecology departments of Belgian university hospitals or affiliated institutions conducted a prospective study from 1984 to 1992 in which the results of prenatal ultrasound examinations were compared to examination reports of the neonates. The results of the period 1984-89 (PI) have been published previously, and those of the period 1990-92 (PII) are presented here. Some very minor congenital anomalies, as listed and defined in the EUROCAT Register, were excluded. Of 26,147 pregnant women at normal risk for congenital anomalies, 25,046 had at least one ultrasound scan (96%). A total of 616 fetuses were structurally abnormal (prevalence 2.42%), and 685 abnormalities were recorded. The sensitivity of the ultrasound test was 40.4% in PI and 51.1% in PII for abnormal fetuses (p < 0.05), and 45% (PI) and 64% (PII) for abnormalities (p < 0.01). The specificity was 99.9% and the positive and negative predictive values were 94.2% and 98.6%, respectively; these values did not differ significantly between the two periods. The sensitivity for the detection of anomalies before 23 weeks increased from 21% in PI to 41% in PII, indicating an improvement in the early detection of fetal abnormalities.

Reconstitution of manganese oxide cores in horse spleen and recombinant ferritins

The formation of Mn(III) oxyhydroxide (MnOOH) cores within the nanoscale cavity of the iron storage protein ferritin has been investigated by electron microscopy and visible absorption spectroscopy. At pH 8.9, discrete amorphous MnOOH cores were formed within horse spleen apoferritin at a range of metal:protein ratios, as well as in ferritin molecules seeded with a small ferrihydrite nucleus. Analysis of the resultant core size distributions showed that the reconstitution of horse spleen apoferritin with Mn(II) was similar to that observed previously for Fe(II) reconstitution in recombinant human L-chain ferritin, suggesting that horse spleen apoferritin does not exhibit Mn(II) oxidase activity at pH 8.9. Reconstitution with MnOOH shows essentially "all-or-nothing" behavior in which many protein molecules remain unmineralized whilst others are loaded to maximum capacity. Kinetic studies showed no significant differences between horse spleen ferritin, recombinant H- and L-chain homopolymers, and H-chain variants containing site-directed modifications at the ferroxidase and putative Fe nucleation centers. Our results indicate that the reconstitution of ferritin with MnOOH cores proceeds by a nonspecific pathway. We propose that the outer surface of the protein inhibits the development of MnOOH nuclei in bulk solution whereas the inner surface is inactive, enabling nucleation and growth to proceed unperturbed within the cavity. One possibility is that differences in the general polyelectrolyte properties of these two surfaces, rather than site-specific charges, account for the "Janus" behavior of the molecule. A similar mechanism might also increase the specificity of iron oxide mineralization in ferritins that lack ferroxidase centers.

New antianginal nitro esters with reduced hypotensive activity. Synthesis and pharmacological evaluation of 3-[(nitrooxy)alkyl]-2H-1,3-benzoxazin-4(3H)-ones

New nitro ester 3-[(nitrooxy)alkyl]-2H-1,3-benzoxazin-4(3H)-ones show marked inhibitory activity against ischemia-induced electrocardiographic changes, with only limited systemic hemodynamic effects, and are reported in the present study. These new nitro vasodilators are potent inhibitors of the electrocardiographic T-wave and S-T segment elevation induced by intravenous or intracoronary administration of Arg-vasopressin or methacholine in the anesthetized rat. The most active compounds are up to 300- and 600-fold more potent than glyceryl trinitrate or Nicorandil, respectively. These nitro esters relax in a concentration-dependent manner the isolated rabbit aorta, at higher concentrations (2-40-fold) than glyceryl trinitrate, and reduce the mean arterial blood pressure at doses 7-300-fold higher than those required by glyceryl trinitrate to exert a similar hypotensive effect. Remarkably, these compounds retain their anti-ischemic and hemodynamic profile after oral (po) administration. These new nitro ester derivatives, endowed with a marked antianginal activity, which is not associated with concurrent and pronounced falls in systemic blood pressure, represent the leads of a new class of selective nitrovasodilators having a preferential action on large coronary vessels, which could be clinically relevant in the treatment of coronary artery diseases.

Construction of a ferroxidase center in human ferritin L-chain

Ferritins are 24-mer proteins which store and detoxify intracellular iron. Mammalian ferritins are made of two subunit types, the H- and L-chains, with different functional specificity. The H-chain has a metal-binding site (the ferroxidase center) which confers ferroxidase activity to the protein and accelerates iron incorporation. In the L-chain the center is substituted by a salt bridge. We performed several site-directed mutageneses in the L-chain with the aim to construct the center and confer ferroxidase activity to the protein. Most variants were insoluble and did not refold into homopolymers, probably due to electrostatic repulsion introduced by the substitutions. However, they formed hybrids when they were renatured together with the L- or H-chains. The heteropolymers made of 90% L-chain and 10% of an L-variant with all the ligand residues of the H-chain center had 25-30% of the ferroxidase activity of the H-chain homopolymer. This corresponds to the activity of an H/L heteropolymer with 7% H-chain. It is concluded that: (i) it is possible to construct a ferroxidase center in the L-chain with an activity equivalent to that of the H-chain, (ii) the residues of the center interfere with the folding/assembly of the L-, but not of the H-chain, (iii) heteropolymers can be made even between ferritin subunits with large differences of refolding rates.

The Colorado differentiated practice model

The Colorado Differentiated Practice Model for Nurses has been implemented at a community hospital and is decreasing patient length of stay while simultaneously becoming a satisfaction factor for nurses, physicians, patients and families. Also, a new role, with more responsibility and authority, has evolved for the BSN-prepared staff nurse.

Iron incorporation into ferritins: evidence for the transfer of monomeric Fe(III) between ferritin molecules and for the formation of an unusual mineral in the ferritin of Escherichia coli

Iron that has been oxidized by H-chain ferritin can be transferred into other ferritin molecules before it is incorporated into mature ferrihydrite iron cores. Iron(III) dimers are formed at the ferroxidase centres of ferritin H chains at an early stage of Fe(II) oxidation. Mössbauer spectroscopic data now show that the iron is transferred as monomeric species arising from dimer dissociation and that it binds to the iron core of the acceptor ferritin. Human H-chain ferritin variants containing altered threefold channels can act as acceptors, as can the ferritin of Escherichia coli (Ec-FTN). A human H-chain ferritin variant with a substituted tyrosine (rHuHF-Y34F) can act as a donor of Fe(III). Since an Fe(III)-tyrosinate (first identified in bullfrog H-chain ferritin) is absent from variant rHuHF-Y34F, the Fe(III) transferred is not derived from this tyrosinate complex. Mössbauer parameters of the small iron cores formed within Ec-FTN are significantly different from those of mammalian ferritins. Analysis of the spectra suggests that they are derived from both ferrihydrite and non-ferrihydrite components. This provides further evidence that the ferritin protein shell can influence the structure of its iron core.

Non-steroidal anti-inflammatory drugs: how do they damage the gut?

NSAIDs are widely prescribed for the treatment of musculoskeletal disorders. The gastrointestinal tract, predominantly the stomach, bears the brunt of their side-effects. The basis of this toxicity is certainly multifactorial, with a wide range of local effects and mucosal defences being implicated. This review will highlight: (1) the epidemiology of NSAID-induced gastrointestinal toxicity; (2) their effects on prostaglandins, and the phenomenon of cytoprotection; (3) effects on neutrophil function; (4) effects on mucosal blood flow; (5) responses of the mucosa to damage (restitution, adaptation, and regenerative repair); (6) the relevance of growth factors; (7) interactions with Helicobacter pylori in ulcerogenesis, and finally (8) the effects of NSAIDs on the small intestine and colon.

The role of the L-chain in ferritin iron incorporation. Studies of homo and heteropolymers

Mammalian ferritins are 24-meric proteins composed of variable proportions of H and L-subunits. The L-chain, in contrast to the H-chain, lacks detectable ferroxidase activity, and its role in ferritin iron incorporation is unclear. In this study, apoferritins were subjected to iron loading with large iron increments to favour spontaneous iron hydrolysis. The homopolymers of the wild-type H-chain, and of a mutant H-chain with an inactivated ferroxidase centre, formed massive protein aggregates, while the L-chain homopolymers remained mostly soluble. The difference between H and L-ferritins was not related to the rate of iron oxidation or to the presence of preformed iron cores. Heteropolymers were constructed in vitro by co-renaturing different proportions of the H-chain with the L-chain or mutant H-chain with an inactivated ferroxidase centre. After loading with high iron increments, protein aggregation of the heteropolymers was reduced when the L-chain content was above 70 to 80%, either in combination with the wild-type H-chain or with the inactivated mutant H-chain. Under acidic conditions (pH 5.5, 1000 Fe atoms per molecule) the heteropolymers with about 20% H and 80% L-chains incorporated three to fourfold more iron into soluble 24-mers than the homopolymers. The data indicate that ferritins with more than 18 L-chains per molecule have the capacity to lower non-specific iron hydrolysis in bulk solution. This property is possibly due to a specific attraction of the incoming oxidized iron into the cavity and may be related to an effect of the L-chain on the cavity microenvironment. It is concluded that under high iron increments the ferritins with high L:H-chain ratios are the most efficient in incorporating iron, and this goes some way to explain why iron storage tissues contain L-rich isoferritins.

Human ferritin H-chains can be obtained in non-assembled stable forms which have ferroxidase activity

We found conditions to obtain the Leu-169-->Arg mutant of human ferritin H chain in a stable and non-assembled state. The protein obtained is an oligomer of subunits with a high degree of structured conformation, and when concentrated it re-assembles into ferritin cages. Functional studies showed that (i) it promotes iron oxidation like the assembled ferritin, but at slower rate, (ii) it is readily precipitated by the oxidised iron unless apotransferrin or L-chain ferritin are added to sequester Fe(III). The results confirm that ferroxidase activity is located within the H-chain, and indicate that the cages of the fully assembled ferritins are important not only in maintaining iron in a soluble form, but also in eliciting the activity of the ferroxidase centres.

Cloning, expression, and immunological characterization of recombinant Lolium perenne allergen Lol p II

The molecular cloning of the cDNA encoding for an isoallergenic form of Lol p II, a major rye grass (Lolium perenne) pollen allergen, was performed by polymerase chain reaction amplification on mRNA extracted from pollen. The amino acid sequence derived from the cDNA was truncated by 4 and 5 residues at the NH2- and COOH-terminal ends, respectively, and differed only in one position from that previously reported. This cDNA was expressed in Escherichia coli by fusion to the carboxyl terminus of the human ferritin H-chain. The molecule was produced in high yields as a soluble protein and was easily purified. The protein retains the multimeric quaternary structure of ferritin, and it exposes on the surface the allergenic moiety, which can be recognized in Western blotting and in enzyme-linked immunosorbent assay experiments by specific IgE from allergic patients. The recombinant allergen was used to analyze the sera of 26 patients allergic to L. perenne compared with control sera. The results were in good agreement with the values obtained with the radioallergosorbent test assay. In addition, histamine release experiments in whole blood from an allergic patient and skin prick tests showed that the recombinant allergen retains some of the biological properties of the natural compound. These findings indicate that the availability of homogeneous recombinant allergens may be useful for the development of more specific diagnostic and therapeutic procedures. Moreover, this expression system may be of more general interest for producing large amounts of soluble protein domains in E. coli.

Ferroxidase kinetics of human liver apoferritin, recombinant H-chain apoferritin, and site-directed mutants

A detailed study of the kinetics of iron(II) oxidation by molecular oxygen in natural and recombinant human apoferritins has been carried out using electrode oximetry to better understand the ferroxidase activity of the protein shell. A comparative study of recombinant L-chain ferritin (rLF), recombinant H-chain ferritin (rHF), and variants has shown that (1) rLF lacks a ferroxidase activity, confirming the results of previous studies; (2) the ferroxidase site of rHF involves Glu-62 and His-65, presumably as Fe2+ ligands, since mutation of these residues abolishes most of the oxidase activity, in agreement with previous studies; and (3) mutation of both the putative ferroxidase and nucleation site ligands in rHF renders the protein totally incapable of catalyzing the oxidation of Fe2+ whereas mutation of nucleation site ligands alone (Glu-61, Glu-64, and Glu-67) decreases the activity only slightly. Analysis of the kinetics of rHF and natural human liver ferritin (HLF) (4% H-chain, 96% L-chain) gave the following apparent parameters at pH 7: Km,O2 = 6 +/- 2 microM, Km,Fe = 80 +/- 10 microM, and kcat = 201 +/- 14 min-1 for rHF and Km,O2 = 60 +/- 12 microM, Km,Fe = 50 +/- 10 microM, and kcat = 31.2 +/- 0.6 min-1 for HLF. Furthermore, Zn2+ was shown to be a noncompetitive inhibitor of Fe2+ oxidation in rHF but a mixed inhibitor in HLF. These different forms of Zn2+ inhibition in the two proteins and the higher activity of HLF than expected, based on its H-chain composition as well as differences in their enzyme kinetic parameters, suggest that H- and L-chains cooperate in modulating the ferroxidase activity of the apoferritin even though the L-subunit lacks a ferroxidase site itself.

Production and characterization of recombinant heteropolymers of human ferritin H and L chains

Vertebrate ferritins are iron storage proteins composed by 24 subunits of one or more types. The recombinant homopolymers of human ferritin H- and L-type chains differ in iron uptake and in physical stability, but the properties of heteropolymers with various proportions of H- and L-type chains cannot be predicted. Present study shows that unfolded human ferritin H- and L- type chains renature under similar conditions to form homopolymers indistinguishable from the native ones and that, when mixed, the unfolded H and L chains renature to form heteropolymers with restricted heterogeneity and with the expected H:L ratios. Seven of these ferritins with different H:L ratios were analyzed; electrophoretic mobility, immunological reactivity, and stability to guanidine denaturation varied as predicted, based on the homopolymers. In contrast, the rate of iron uptake, monitored by the variation of absorbance at 310 nm, increased in the ferritins that ranged in H chain content from 0 to 35%; further increments in H chains had no additional effect. This finding indicates that, under the present conditions, only a limited number of H chains are needed for the maximum rate of ferritin iron uptake. Variations of L- and H-type chains in vivo may thus have biological relevance.

Chronic liver disease due to hepatitis C

The low concentration of hepatitis C virus in the blood of infected patients has made it difficult to detect. Infected patients can now be identified by using more sensitive immunoassays and amplification of viral RNA by the polymerase chain reaction. Nevertheless, the virus remains difficult to eliminate. We present the case of a woman with a history of autoimmune haemolytic anaemia, thrombocytopenia, and common variable immunodeficiency who developed chronic hepatitis.