Scandcleft randomized trials of primary surgery for unilateral cleft lip and palate: Speech proficiency at 10 years of age

BACKGROUND & AIM

To assess consonant proficiency and velopharyngeal function in 10-year-old children born with unilateral cleft lip and palate (UCLP) within the Scandcleft project.

METHODS & PROCEDURES

Three parallel group, randomized, clinical trials were undertaken as an international multicentre study by nine cleft teams in five countries. Three different surgical protocols for primary palate repair (Arm B-Lip and soft palate closure at 3-4 months, hard palate closure at 36 months, Arm C-Lip closure at 3-4 months, hard and soft palate closure at 12 months, and Arm D-Lip closure at 3-4 months combined with a single-layer closure of the hard palate using a vomer flap, soft palate closure at 12 months) were tested against a common procedure (Arm A-Lip and soft palate closure at 3-4 months followed by hard palate closure at 12 months) in the total cohort of 431 children born with a non-syndromic UCLP. Speech audio and video recordings of 399 children were available and perceptually analysed. Percentage of consonants correct (PCC) from a naming test, an overall rating of velopharyngeal competence (VPC) (VPC-Rate), and a composite measure (VPC-Sum) were reported.

OUTCOMES & RESULTS

The mean levels of consonant proficiency (PCC score) in the trial arms were 86-92% and between 58% and 83% of the children had VPC (VPC-Sum). Only 50-73% of the participants had a consonant proficiency level with their peers. Girls performed better throughout. Long delay of the hard palate repair (Arm B) indicated lower PCC and simultaneous hard and soft palate closure higher (Arm C). However, the proportion of participants with primary VPC (not including velopharyngeal surgeries) was highest in Arm B (68%) and lowest in Arm C (47%).

CONCLUSIONS & IMPLICATIONS

The speech outcome in terms of PCC and VPC was low across the trials. The different protocols had their pros and cons and there is no obvious evidence to recommend any of the protocols as superior. Aspects other than primary surgical method, such as time after velopharyngeal surgery, surgical experience, hearing level, language difficulties and speech therapy, need to be thoroughly reviewed for a better understanding of what has affected speech outcome at 10 years.

WHAT THIS PAPER ADDS

What is already known on the subject Speech outcomes at 10 years of age in children treated for UCLP are sparse and contradictory. Previous studies have examined speech outcomes and the relationship with surgical intervention in 5-year-olds. What this study adds to the existing knowledge Speech outcomes based on standardized assessment in a large group of 10-year-old children born with UCLP and surgically treated according to different protocols are presented. While speech therapy had been provided, a large proportion of the children across treatment protocols still needed further speech therapy. What are the potential or actual clinical implications of this work? Aspects other than surgery and speech function might add to the understanding of what affects speech outcome. Effective speech therapy should be available for children in addition to primary surgical repair of the cleft and secondary surgeries if needed.

EU sampling strategies for the detection of veterinary drug residues in aquaculture species: are they working?

Over the past 50 years, the culture of aquatic species in controlled conditions to enhance production has grown in importance and now provides nearly 50% of the world's seafood supply. In part, this expansion has been made possible by the use of antibiotics, antifungals, and other veterinary medicines to control disease and improve welfare. Despite guidelines being available, the sampling programmes for drug residue surveillance of aquaculture products recommended by the CODEX Alimentarius Commission were withdrawn in 2008 and put under review. Directive 96/23/EC sets out legislation to govern how sampling programmes for drug residue surveillance should be conducted within the EU. This directive applies both to produce raised within the EU and also imported products from third countries. This communication examines the existing EU sampling regimen for aquaculture products and comments on its possible application in a global context. We examine UK statutory sampling data that, while indicating the effectiveness of the directive, also suggests that the directive may lead to unnecessary sampling. Regarding imports, examination of the Rapid Alert System for Food and Feed (RASFF) database using process control charts and statistical modelling suggests that the sampling regimen described in the directive is effective but not sufficiently flexible for the range of aquaculture practices that exist. Limitations of the directive, datasets, and practices are further discussed.

Indentation device for in situ Raman spectroscopic and optical studies

Instrumented indentation is a widely used technique to study the mechanical behavior of materials at small length scales. Mechanical tests of bulk materials, microscopic, and spectroscopic studies may be conducted to complement indentation and enable the determination of the kinetics and physics involved in the mechanical deformation of materials at the crystallographic and molecular level, e.g., strain build-up in crystal lattices, phase transformations, and changes in crystallinity or orientation. However, many of these phenomena occurring during indentation can only be observed in their entirety and analyzed in depth under in situ conditions. This paper describes the design, calibration, and operation of an indentation device that is coupled with a Raman microscope to conduct in situ spectroscopic and optical analysis of mechanically deformed regions of Raman-active, transparent bulk material, thin films or fibers under contact loading. The capabilities of the presented device are demonstrated by in situ studies of the indentation-induced phase transformations of Si thin films and modifications of molecular conformations in high density polyethylene films.

A new model for myxosporean (Myxozoa) development explains the endogenous budding phenomenon, the nature of cell within cell life stages and evolution of parasitism from a cnidarian ancestor

The phylum Myxozoa is composed of endoparasitic species that have predominately been recorded within aquatic vertebrates. The simple body form of a trophic cell containing other cells within it, as observed within these hosts, has provided few clues to relationships with other organisms. In addition, the placement of the group using molecular phylogenies has proved very difficult, although the majority of analyses now suggest that they are cnidarians. There have been relatively few studies of myxozoan stages within invertebrate hosts, even though these exhibit multicellular and sexual stages that may provide clues to myxozoan evolution. Therefore an ultrastructural examination of a myxozoan infection of a freshwater oligochaete was conducted, to reassess and formulate a model for myxozoan development in these hosts. This deemed that meiosis occurs within the oligochaete, but that fertilisation is not immediate. Rather, the resultant haploid germ cell (oocyte) is engulfed by a diploid sporogonic cell (nurse cell) to form a sporoplasm. It is this sporoplasm that infects the fish, resulting in the multicellular stages observed. Fertilisation occurs after the parasites leave the fish and enter the oligochaete host. The nurse cell/oocyte model explains previously conflicting evidence in the literature regarding myxosporean biology, and aligns phenomena considered distinctive to the Myxozoa, such as endogenous budding and cell within cell development, with processes recorded in cnidarians. Finally, the evolutionary origin of the Myxozoa as cnidarian parasites of ova is hypothesised.

Sacculogenesis of Buddenbrockia plumatellae (Myxozoa) within the invertebrate host Plumatella repens (Bryozoa) with comments on the evolutionary relationships of the Myxozoa

Members of the phylum Myxozoa are obligate parasites, primarily of aquatic organisms. Their phylogeny has remained problematic, with studies placing them within either the Bilateria or Cnidaria. The discovery that the enigmatic Buddenbrockia plumatellae is a myxozoan that possesses distinct bilaterian features appeared to have finally resolved the debate. B. plumatellae is described as a triploblastic 'worm-like' organism, within which typical myxozoan malacospores form. Using EM we examined the early development of the B. plumatellae 'worms' within the bryozoan host Plumatella repens. The initial development involved numerous unicellular, amoeboid pre-saccular stages that were present within the basal lamina of the host's body wall. These stages migrate immediately beneath the peritoneum where a significant host tissue reaction occurs. The stages aggregate, initiating the formation of a 'worm'. The base of a developing 'worm' forms a pseudosyncytium which resolves into an ectoderm surrounding a mesendoderm. The pseudosyncytium is directly anchored into neighbouring host cells via masses of striated fibres. The replication of the ectodermal and mesendodermal cells extends the developing 'worm' into the coelom of the host. The mesendoderm resolves to form a mesoderm and an endoderm. Myogenesis appears to be initiated from the anchored end of the 'worm' and develops along the mesoderm. The aggregation and differentiation of amoeboid pre-saccular stages to initiate the 'worm' draws analogies to the sacculogenesis observed for Tetracapsuloides bryosalmonae, B. plumatellae's sister taxon within the class Malacosporea. The development of a multicellular, spore forming organism, from single cells does not correlate to any bilaterian or cnidarian species. Current phylogenies indicate the Myxozoa are basal bilaterians along with the Acoela and Mesozoa. Comparison with these other basal groups may help to resolve the placement of Myxozoa within the tree of life.

Endogenous inhibitors (GALFs) of 11beta-hydroxysteroid dehydrogenase isoforms 1 and 2: derivatives of adrenally produced corticosterone and cortisol

Two isoforms of 11beta-HSD exist; 11beta-HSD1 is bi-directional (the reductase usually being predominant) and 11beta-HSD2 functions as a dehydrogenase, conferring kidney mineralocorticoid specificity. We have previously described endogenous substances in human urine, "glycyrrhetinic acid-like factors (GALFs)", which like licorice, inhibit the bi-directional 11beta-HSD1 enzyme as well as the dehydrogenase reaction of 11beta-HSD2. Many of the more potent GALFs are derived from two major families of adrenal steroids, corticosterone and cortisol. For example, 3alpha5alpha-tetrahydro-corticosterone, its derivative, 3alpha5alpha-tetrahydro-11beta-hydroxy-progesterone (produced by 21-deoxygenation of corticosterone in intestinal flora); 3alpha5alpha-tetrahydro-11beta-hydroxy-testosterone (produced by side chain cleavage of cortisol); are potent inhibitors of 11beta-HSD1 and 11beta-HSD2-dehydrogenase, with IC50's in range 0.26-3.0 microM, whereas their 11-keto-3alpha5alpha-tetrahydro-derivatives inhibit 11beta-HSD1 reductase, with IC50's in range 0.7-0.8 microM (their 3alpha5beta-derivatives being completely inactive). Inhibitors of 11beta-HSD2 increase local cortisol levels, permitting it to act as a mineralocorticoid in kidney. Inhibitors of 11beta-HSD1 dehydrogenase/11beta-HSD1 reductase serve to adjust the set point of local deactivation/reactivation of cortisol in vascular and other glucocorticoid target tissues, including adipose, vascular, adrenal tissue, and the eye. These adrenally derived 11-oxygenated C21- and C19 -steroidal substances may serve as 11beta-HSD1- or 11beta-HSD2-GALFs. We conclude that adrenally derived products are likely regulators of local cortisol bioactivity in humans.

Sacculogenesis and sporogony of Tetracapsuloides bryosalmonae (Myxozoa: Malacosporea) within the bryozoan host Fredericella sultana (Bryozoa: Phylactolaemata)

Tetracapsuloides bryosalmonae is the myxozoan parasite responsible for proliferative kidney disease (PKD) of salmonid fishes. This disease affects farmed species in North America and Western Europe where it results in significant economic losses for the rainbow trout industry. The parasite has two hosts in its life cycle, salmonid fish, and freshwater bryozoans. In this study, we describe the development of the parasite at the ultrastructural level within the bryozoan host Fredericella sultana. Single celled, presaccular stages form aggregates within the metacoel of this host which resolve into spore sacs. Within these sacs sporogenesis is initiated with the differentiation of presporogonic cells into sporogonic and valvogenic cells. These latter cells surround a sporogonic cell which subsequently divides to form a sporoplasmogenic cell and a capsulogenic cell. The capsulogenic cell divides further to form four cells each with a polar capsule, while the sporoplasmogenic cell divides resulting in four cells, two primary cells and two secondary cells. The secondary cells are engulfed by the primary cells resulting in a mature sporoplasm. It is hypothesized that autogamy occurs during the initial formation of the spore sac and that allogamy is also possible during this time.

Transmission of Tetracapsuloides bryosalmonae (Myxozoa: Malacosporea), the causative organism of salmonid proliferative kidney disease, to the freshwater bryozoan Fredericella sultana

Proliferative kidney disease (PKD), caused by the malacosporean parasite Tetracapsuloides bryosalmonae, causes significant losses among salmonids in Western Europe and North America. The role of salmonid fish in the life-cycle of this parasite has been conjectured upon for over a quarter of a century. To examine whether fish can transmit the infection to bryozoans, the known invertebrate host, water containing parasitized brown trout Salmo trutta was pumped into tanks containing colonies of Fredericella sultana collected from the wild. The specific parasite-free status of these colonies being first assessed, by PCR and prolonged laboratory culture. After 6 weeks exposure to the brown trout aquarium effluent, portions of these colonies displayed overt infections with T. bryosalmonae. This was in contrast to control bryozoans, derived from the experimental colonies prior to exposure, which remained T. bryosalmonae negative. In addition, spores obtained from the experimentally infected colonies were exposed to naïve rainbow trout, resulting in clinical PKD, thus completing a cycle of transmission. During the experiments, the infection was noted to inhibit statoblast formation within bryozoans and appeared to be pathogenic, finally killing the bryozoan host. These findings indicate that fish can transmit the parasite to bryozoans and are an integral part of this parasite's life-cycle.

Transmission of freshwater myxozoans during the asexual propagation of invertebrate hosts

The phylum Myxozoa contains over 1350 species almost all of which are considered to be obligate parasites of aquatic animals. The phylum is composed of two classes, the Myxosporea and the Malacosporea, species of which are important pathogens responsible for severe economic losses in cultured fisheries. The life cycles of freshwater Myxozoa are believed to involve horizontal, indirect transmission, involving an invertebrate (oligochaetes or bryozoans) and a vertebrate host (fish or amphibians). Here, we describe myxozoan propagation through the fragmentation of invertebrate hosts to form new infected individuals. The two hosts examined are an oligochaete Lumbriculus variegatus infected with an unidentified myxosporean (Triactinomyxon sp.) and the bryozoan Fredericella sultana infected with the malacosporean Tetracapsuloides bryosalmonae which causes proliferative kidney disease, a major constraint of the European rainbow trout industry. Such intra-clonal propagation is a novel form of vertical transmission that is likely to be widespread within the Myxozoa and could form an important method by which some of these parasites maintain and proliferate within the aquatic environment.

Immunostaining of spores and plasmodia of disparate myxozoan genera with comments on the properties of the sporular mucus envelope

Species of the phylum Myxozoa are common parasites of fish and can cause severe losses in cultured species. Although a number of myxozoan life-cycles have now been elucidated, little is known about the biology of these organisms in the fish host. Monoclonal antibody B4 raised to the myxozoanTetracapsuloides bryosalmonaehas been previously noted to react with a number of species infecting fish kidney. We present the results of a survey of 55 myxosporean species that determined that this antibody detects an antigen on the spore surface of 33 of these species in the generaMyxobolus,SphaerosporaandThelohanellus. However, there appears to be no clear relationship between those spores that contain the MAb B4 reactive antigen and the host or organ in which they are detected. The antigen appears to be synthesized in the plasmodial cytoplasm and is intimately associated with the surface of the spore capsules and, where present, the mucus envelope. The nature of this envelope is further discussed in relation to its formation and distinctive properties.

Severe, chronic proliferative kidney disease (PKD) induced in rainbow trout Oncorhynchus mykiss held at a constant 18 degrees C

Proliferative kidney disease (PKD), caused by the myxozoan parasite Tetracapsuloides bryosalmonae, is well documented as a seasonal disease of rainbow trout Oncorhynchus mykiss. Water temperatures influence the course of the infection both within the fish and the invertebrate host, the recovery of fish from the disease being accelerated with decreasing water temperatures. During this study, groups of rainbow trout were held at a constant temperature (18 degrees C) for a sustained period of time following initial exposure to T. bryosalmonae. While the majority of these fish had recovered from the clinical disease after 9 mo, 10% remained infected, showing clinical signs of disease. A histological study revealed that the majority exhibited very high parasite loads and unusually severe symptoms of PKD. This demonstrates that while most rainbow trout can recover from PKD independent of water temperature, there exists a sub-population that cannot.

Ultrastructural and molecular characterization of Bacillidium vesiculoformis n. sp. (Microspora: Mrazekiidae) in the freshwater oligochaete Nais simplex (Oligochaeta: Naididae)

The development of a new species, Bacillidium vesiculoformis n. sp. (Microspora, Mrazekiidae), is described from the freshwater oligochaete Nais simplex (Oligochaeta, Naididae). Initial stages of parasite development consist of a monokaryotic merogony within a haemocyte of the intestinal blood sinus. The resulting hypertrophied haemocyte is attached to the chloragocytes of the sinus by fine cytoplasmic extensions with the sinus around the cell becoming greatly enlarged. The meronts within the haemocyte form diplokaryotic sporonts that undergo sporogenesis directly within the cytoplasm of the host cell. The infected cell becomes packed with spores and developmental stages, causing it dramatically to increase in size, eventually rupturing the oligochaete and cell. Sporogony appears to be disporoblastic. Released spores were observed to have an adhesive quality. Transmission studies conducted with mature spores failed to transmit the parasite horizontally although vertical transmission was observed. Phylogenetic analysis of the parasite demonstrated that B. vesiculoformis clustered with microsporidian parasites of bryozoa and two other microsporidians, Janacekia debaiseuxi and an unidentified Bacillidium sp.

Localization of carbohydrate terminals on Tetracapsuloides bryosalmonae using lectin histochemistry and immunogold electron microscopy

Tetracapsuloides bryosalmonae is the myxozoan parasite that causes the commercially important proliferative kidney disease (PKD) in salmonid aquaculture. Previous studies on the binding of lectins to T. bryosalmonae identified Griffonia simplificola agglutinin I (GS I) as useful for parasite identification. This lectin was also implicated as recognizing antigenic structures on the parasite. Here, we examine the histochemical staining and ultrastructural localization of a panel of 21 lectins on the extrasporogonic stage of T. bryosalmonae. The histochemical staining studies indicated that the majority of lectins bound to the renal stages of T. bryosalmonae, however not all of these lectins could be successfully localized using immunogold electron microscopy. Of the lectins that were localized many, including GS I, bound to membranes associated with the lysosomal pathway within the extrasporogonic primary cell of the parasite, indicating that these organelles are rich in glycoconjugates. The histochemical staining of Erythrina cristagalli ECL was unique and highlighted a different distribution of glycoconjugates in the periphery of some extrasporogonic parasites within the renal sinuses when compared with stages in the interstitium, suggesting the presence of distinct blood forms of T. bryosalmonae.

In situ hybridisation identifies the gill as a portal of entry for PKX (Phylum Myxozoa), the causative agent of proliferative kidney disease in salmonids

PKX (Phylum Myxozoa) is an important pathogen affecting salmonid culture in Western Europe and North America. All of the available oligonucleotide probes developed for the PCR amplification of PKX DNA were examined for their ability to detect PKX in fixed tissue sections using in situ hybridisation. Out of the 12 probes examined, only four stained PKX in tissue sections. The specificity of these probes to PKX was examined by testing them individually against a range of myxosporean infections. One of the probes (1032) cross-reacted with Sphaerospora truttae infecting brown trout kidney and stained this parasite in tissue sections, while probe 6R stained stickleback DNA. The results from these studies allowed for an optimised, relatively rapid, in situ hybridisation protocol to be developed for PKX detection. Using this protocol, a preliminary study was conducted on the life history of the parasite in the rainbow trout Oncorhynchus mykiss. This demonstrated the presence of PKX in the gill arch 3 days after initial exposure in an enzootic river. It is suggested that a portal of entry for PKX is the gill. From here. it migrates to the kidney where the disease progresses as previously described.

Effects of time after deafening and implantation on guinea pig electrical detection thresholds

Changes in detection threshold level as a function of time after deafening and implantation have been described previously in macaque [Pfingst, 1990] and human [Skinner et al., 1995] cochlear implant subjects. Characterization of the mechanisms underlying these changes will contribute to our understanding of the anatomical and physiological factors affecting electrical stimulus detection. In addition, understanding the time course of early threshold changes is essential to the interpretation of acute physiological studies of cochlear implants. To better characterize time-dependent threshold changes, we monitored changes in guinea pig psychophysical electrical detection thresholds with time after deafening and cochlear implantation. Threshold levels for 100 Hz sinusoidal bursts were initially unstable over the first 30 days post-surgery (DPS), after which thresholds stabilized. At longer intervals (>100 DPS), increases (>10 dB) in threshold level were observed for 100 Hz sinusoids in three of 11 cases. These changes were transient in one case and long-term in two cases. The time course of threshold change, both early and late, could not be explained on the basis of changes in spiral ganglion cell survival. The guinea pig seems to be an ideal preparation for studies of this nature, because threshold changes are similar in type, but accelerated in time course, relative to those observed in primates.

Interactions of mineralocorticoids and glucocorticoids in epithelial target tissues

BACKGROUND

: In Na+-transporting epithelial target tissues, such as mammalian kidney and the isolated toad bladder, glucocorticoids (GCs) do not normally elicit Na+ retention. In mammalian kidney, however, they do cause kaliuresis. The presence of 11beta-hydroxysteroid dehydrogenase isoform 2 (11beta-HSD2) in these target tissues inactivates the GCs, preventing them from accessing mineralocorticoid receptors (MRs) and stimulating Na+ transport.

RESULTS

: The usually observed Na+ retention elicited by the mineralocorticoid aldosterone was blunted when the GC corticosterone was coadministered along with aldosterone. However, when corticosterone was administered along with a 11beta-HSD2 inhibitor, a strong Na+ transport was elicited by an MR-mediated mechanism. 11-Dehydrocorticosterone also blunted aldosterone-elicited Na+ transport in these target tissues.

CONCLUSIONS

: 11beta-HSD2 appears to play two important roles in the epithelial target tissues, kidney and toad bladder. The first is to protect GC access to MR, and the second involves the product of the enzyme to regulate the magnitude of aldosterone-induced Na+ retention.

Observations on the electron-dense bodies of the PKX parasite, agent of proliferative kidney disease in salmonids

Ultrastructural observations on structures associated with the 'haplosporosome'-like electron-dense bodies (EDBs) of the primary cell of the extrasporogonic stage of PKX are described. Observations made include formation of EDBs by the trans-Golgi network, an additional membrane associated with EDB structure, confronting cisternae, engulfment and presence of EDBs in multivesicular bodies, fusion of EDBs with the plasmalemma, degeneration of EDBs in disintegrating primary cells and endocytosis of PKX cytoplasm by adherent macrophages. Immunogold localisation of a PKX-specific monoclonal antibody (MAb A3) suggests that the EDBs contain periodate-sensitive carbohydrates on their membranes. Tissues prepared for immunogold electron microscopy further suggest that some contain a lipid-rich core. An interpretation is made on their possible function and their relationship with the haplosporosomes and sporoplasmasomes found in members of the Haplosporidea and Myxosporea respectively.

The adult respiratory distress syndrome after dextran infusion as an antithrombotic agent in free TRAM flap breast reconstruction

Adult respiratory distress syndrome occurred in a patient who had received dextran as a routine antithrombotic agent during and after free TRAM breast reconstruction. Although most patients who receive dextran have no adverse reaction, particularly after hapten inhibition by dextran 1 infusion, the serious nature of this complication in an elective operation calls into question the continuing routine use of dextran in microsurgery.

Dermal autografts for fascial repair after TRAM flap harvest

To find an alternative to synthetic mesh closure of abdominal fascial defects after transverse rectus abdominis musculocutaneous (TRAM) flap harvest, dermal autografts were removed from tissue to be discarded and used for fascial closure. Dermal grafts have been used for herniorrhaphy and fascial repair after TRAM harvest previously, but have never been systematically studied. The dermal autograft technique was used in 24 patients to repair or reinforce anterior rectus sheath or external oblique fascia after TRAM harvest for breast reconstruction. During the same period, 25 other patients underwent TRAM breast reconstruction with abdominal wall closure by other methods. All patients were followed by serial physical examinations given by the operating surgeon. Average follow-up in the dermal autograft group was 12.6 versus 12.0 months in the second group. In the dermal autograft group, two patients complained of bulging of the anterior abdominal wall; one developed a true hernia, away from the location of the dermal autograft. In the second group, two patients experienced bulging. Wounds and infectious complications were similar in both groups. Dermal autografts are a useful alternative to mesh repair or direct closure of fascial defects after TRAM flap harvest.

Skin-sparing mastectomy and immediate reconstruction: oncologic risks and aesthetic results in patients with early-stage breast cancer

Skin-sparing mastectomy has been advocated as an oncologically safe approach for the management of patients with early-stage breast cancer that minimizes deformity and improves cosmesis through preservation of the skin envelope of the breast. Because chest wall skin is the most frequent site of local failure after mastectomy, concerns have been raised that inadequate skin excision could result in an increased risk of local recurrence. Precise borders of the skin resection have not been well established, and long-term local recurrence rates after skin-sparing mastectomy are not known. The purpose of this study was to evaluate the oncologic safety and aesthetic results for skin-sparing mastectomy and immediate breast reconstruction with a latissimus dorsi myocutaneous flap and saline breast prosthesis. Fifty-one patients with early-stage breast cancer (26 with ductal carcinoma in situ and 25 with invasive carcinoma) undergoing primary mastectomy and immediate reconstruction with a latissimus flap were studied from 1991 through 1994. For 32 consecutive patients, skin-sparing mastectomy was defined as a 5-mm margin of skin designed around the border of the nipple-areolar complex. After the mastectomy, biopsies were obtained from the remaining native skin flap edges. Patients were followed for 44.8 months. Histologic examination of 114 native skin flap biopsy specimens failed to demonstrate breast ducts in the dermis of any of the 32 consecutive patients studied. One of 26 patients with ductal carcinoma in situ had metastases to the skin of the lateral chest wall and back. Four other patients, one with stage I disease and three with stage II-B disease, had recurrent breast carcinoma. The stage I patient had a local recurrence in the subcutaneous tissues near the mastectomy specimen. Two patients suffered axillary relapse, and one had distant metastases to the spine. The findings of this study support the technique of skin-sparing mastectomy as an oncologically safe one, based on an absence of breast ductal epithelium at the margins of the native skin flaps and a local recurrence rate of 2 percent after 45 months of follow-up. Although these results need to be confirmed with greater numbers of patients and longer follow-up, skin-sparing mastectomy and immediate breast reconstruction may be considered an excellent alternative treatment to breast conservation for patients with ductal carcinoma in situ and early-stage invasive breast cancer.

A second enzyme protecting mineralocorticoid receptors from glucocorticoid occupancy

We have confirmed that A6 cells (derived from kidney of Xenopus laevis), which contain both mineralocorticoid and glucocorticoid receptors, do not normally possess 11 beta-hydroxysteroid dehydroxgenase (11 beta-HSD1 or 11 beta-HSD2) enzymatic activity and so are without apparent "protective" enzymes. A6 cells do not convert the glucocorticoid corticosterone to 11-dehydrocorticosterone but do, however, possess steroid 6 beta-hydroxylase that transforms corticosterone to 6 beta-hydroxycorticosterone. This hydroxylase is cytochrome P-450 3A (CYP3A). We have now determined the effects of 3 alpha,5 beta-tetrahydroprogesterone and chenodeoxycholic acid (both inhibitors of 11 beta-HSD1) and 11-dehydrocorticosterone and 11 beta-hydroxy-3 alpha,5 beta-tetrahydroprogesterone (inhibitors of 11 beta-HSD2) and carbenoxalone, which inhibits both 11 beta-HSD1 and 11 beta-HSD2, on the actions and metabolism of corticosterone and active Na+ transport [short-circuit current (Isc)] in A6 cells. All of these 11 beta-HSD inhibitory substances induced a significant increment in corticosterone-induced Isc, which was detectable within 2 h. However, none of these agents caused an increase in Isc when incubated by themselves with A6 cells. In all cases, the additional Isc was inhibited by the mineralocorticoid receptor (MR) antagonist, RU-28318, whereas the original Isc elicited by corticosterone alone was inhibited by the glucocorticoid receptor antagonist, RU-38486. In separate experiments, each agent was shown to significantly inhibit metabolism of corticosterone to 6 beta-hydroxycorticosterone in A6 cells, and a linear relationship existed between 6 beta-hydroxylase inhibition and the MR-mediated increase in Isc in the one inhibitor tested. Troleandomycin, a selective inhibitor of CYP3A, inhibited 6 beta-hydroxylase and also significantly enhanced corticosterone-induced Isc at 2 h. These experiments indicate that the enhanced MR-mediated Isc in A6 cells may be related to inhibition of 6 beta-hydroxylase activity in these cells and that this 6 beta-hydroxylase (CYP3A) may be protecting the expression of corticosterone-induced active Na+ transport in A6 cells by MR-mediated mechanism(s).

Localization of 2 11beta-OH steroid dehydrogenase isoforms in aortic endothelial cells

11Beta-hydroxysteroid dehydrogenase (11beta-HSD) is expressed in vascular smooth muscle cells (VSMC) but has not been reported to be present in vascular endothelial cells. This enzyme assists in regulating the cellular concentration of active endogenous glucocorticoids (GCs). We have observed that endothelium intact rat aortic rings express message for both Type 1 and Type 2 11beta-HSD whereas primary cultures of VSMC express only mRNA for the Type I isoform. Since GCs diminish prostacyclin synthesis in endothelial cells, we hypothesized that 11beta-HSD is present in vascular endothelial cells. In primary cultures of rat aortic endothelial (RAE) cells, mRNA from both isoforms of 11beta-HSD could be detected by RT-PCR with higher levels of the Type 1 isoform. The oxo-reductase reaction "activating" 11-dehydro metabolites back to the parent steroid is the preferred enzyme direction (12:1 after a 120 minutes steroid incubation) in intact RAE cells. When RAE cells are grown in the presence of antisense oligonucleotides specific for Type 1 11beta-HSD, oxo-reductase activity is decreased by approximately 50% but the dehydrogenase reaction, which inactivates endogenous GCs and is characteristic of the Type 2 isoform, is unaffected. Thus endothelial cells appear to express both isoforms of 11beta-HSD; the Type 1 isoform dominates functioning in the oxo-reductase mode. Inhibition of the oxo-reductase reaction may lower the local concentrations of GC and indirectly allow for increased production of prostacyclin in endothelial cells.

COMPTEL measurements of the omnidirectional high-energy neutron flux in near-earth orbit

On four occasions, twice in 1991 (near solar maximum) and twice in 1994 (near solar minimum), one COMPTEL D1 detector module was used as an omnidirectional detector to measure the high-energy (> 12.8 MeV) neutron flux near an altitude of 450 km. The D1 modules are cylindrical, with radius 13.8 cm and depth 8 cm, and are filled with liquid scintillator (NE213A). The combined flux measurements can be fit reasonably well by a product of the Mt. Washington neutron monitor rate, a linear function in the spacecraft geocenter zenith angle, and an exponential function of the vertical geomagnetic cutoff rigidity in which the coefficient of the rigidity is a linear function of the neutron monitor rate. When pointed at the nadir, the flux is consistent with that expected from the atmospheric neutron albedo alone. When pointed at the zenith the flux is reduced by a factor of about 0.54. Thus the production of secondary neutrons in the massive (16000 kg) Compton Gamma-Ray Observatory spacecraft is negligible. Rather, the mass of the spacecraft provides shielding from the earth albedo.

Impact of dietary Na+ on glycyrrhetinic acid-like factors (kidney 11beta-(HSD2)-GALFs) in human essential hypertension

Our previous studies have shown that human urine contains glycyrrhetinic acid-like factors (GALFs) that possess inhibitory activity against kidney 11beta-hydroxysteroid dehydrogenase isoform 2 (HSD2). The present studies were undertaken to determine the impact of dietary Na+ intake on the levels of kidney 11beta(HSD2)-GALFs. The excretion of kidney 11beta(HSD2)-GALFs in 24-hour urine samples of 30 unmedicated subjects (10 normotensive and 10 high/normal-renin and 10 low-renin essential hypertensive subjects) on both 200- and 10-mmol Na+ diets was studied. No differences in the urinary levels of kidney 11beta(HSD2)-GALFs were observed among the three groups on the high-Na+ diet. However, with a low-Na+ diet, the levels of kidney 11beta(HSD2)-GALFs were significantly increased in hypertensive subjects but not in normal subjects. Levels increased from 8.3+/-1.4 to 17.3+/-2.9 and 6.7+/-1.3 to 10.6+/-1.4 carbenoxolone sodium units/d in high/normal-renin (P=.01) and low-renin hypertensive subjects (P=.07), respectively; normal subjects changed from 8.0+/-1.9 to 10.6+/-2.4. The levels of kidney 11beta(HSD2)-GALFs were significantly higher in the high/normal-renin hypertensive subjects than in either the control normotensive subjects or the low-renin hypertensive subjects when challenged with the low-Na+ diet (P<.05 by Wilcoxon rank-sum test). The greater response of the high/normal-renin essential hypertensive subjects indicated that they may utilize kidney 11beta(HSD2)-GALFs when challenged with a low-Na+ diet, whereas the low-renin essential hypertensive subjects do not.

Breast infarction after internal mammary artery harvest in a patient with calciphylaxis

The use of the internal mammary artery during coronary artery bypass grafting is commonplace. Complications associated with the harvest of the internal mammary artery have predominantly been wound related. These range from skin dehiscence to complete avascular necrosis of the sternum. This report documents complete ischemic necrosis of a breast in a patient with end-stage renal disease and a history of calciphylaxis, after the harvest of an internal mammary artery.

11Beta-hydroxysteroid dehydrogenase in the Dahl rat

Dahl salt sensitive (Dahl-S) rats develop hypertension soon after birth. The cause of the increased salt-sensitivity in the Dahl-S rat is unknown. The mineralocorticoid specificity of the kidney receptor is conferred by the activity of 11beta-hydroxysteroid dehydrogenase (11beta-HSD). There are two isoforms of 11beta-HSD (11beta-HSD1 and 11beta-HSD2). Deficiency or inhibition of 11beta-HSD2 causes sodium retention and hypertension. In the present study we measured the activity of hepatic and kidney 11beta-HSD1 in Dahl-S and R rats before and after the development of hypertension. The activity of 11beta-HSD1 in the liver was lower in the Dahl-S rats at 6 weeks of age (S = 8.01 +/- 0.89 v R = 11.91 +/- 0.84 nmol/mg protein/10 min (P < .02) but there was no difference at 10 weeks. In contrast, 11beta-HSD1 in the kidney was not different at 6 weeks but it was significantly lower in the Dahl-S rats at 10 weeks (S = 0.91 +/- 0.04 v R = 1.12 +/- 0.01 nmol/mg protein/10 min (P < .001). Plasma renin concentration was lower at 6 (6w) and 10 weeks (10w) in the Dahl-S rats: S-6w = 4.2 +/- 0.4 versus R-6W = 6.3 +/- 0.8 ng angiotensin I (AI)/mL/h (P < .04) and S-10w = 6.4 +/- 0.7 versus R-10w = 10 +/- 0.9 ng AI/mL/h (P < .009). Plasma aldosterone and corticosterone were not different between the two strains. Systolic blood pressure (SBP) in the Dahl-S rats was 124 +/- 3 mm Hg at 6 weeks and 241 +/- 6 mm Hg at 10 weeks (P < .001). SBP in the Dahl-R rats was 113 +/- 5 mm Hg at 6 weeks and 143 +/- 4 mm Hg at 10 weeks. In conclusion, Dahl-S rats have lower hepatic 11beta-HSD1 activity at 6 weeks of age and lower kidney 11beta-HSD1 at 10 weeks of age compared with Dahl-R rats of the same age. These findings suggest that diminished activity of both liver and kidney 11beta-HSD1 may play a role in the salt sensitivity and development of hypertension in the Dahl-S rat.

11BetaOH-progesterone affects vascular glucocorticoid metabolism and contractile response

Vascular smooth muscle (VSM) contains a bidirectional isoform of 11beta-hydroxysteroid dehydrogenase (11beta-HSD), the enzyme that can metabolize endogenous glucocorticoids to their respective 11-dehydro derivatives. 11BetaOH-progesterone (11betaOH-P), a compound that can be produced in vivo, is as potent or more potent than licorice derivatives in inhibiting renal and hepatic 11beta-HSD. When studied in homogenates prepared from primary cultures of rat VSM, 11betaOH-P and its derivative, 11-keto-progesterone (11-keto-P), proved to be potent, directionally specific inhibitors of vascular 11beta-HSD. 11BetaOH-P selectively inhibited the forward dehydrogenase reaction (corticosterone-->11-dehydrocorticosterone), whereas 11-keto-P selectively blocked the reverse oxidoreductase reaction. To test the physiological effects, vascular rings were prepared from rat aorta. Rings were incubated in culture media containing either a submaximal concentration of corticosterone (10 nmol/L), 11-dehydrocorticosterone (100 nmol/L), 11betaOH-P (1 micromol/L), 11-keto-P (1 micromol/L), or a combination of glucocorticoid and inhibitor for 24 hours. After the 24-hour incubation, rings were briefly stimulated sequentially with phenylephrine (10 nmol/L to 1 micromol/L) and angiotensin II (1 micromol/L). The immediate contractile response in rings incubated with both corticosterone and 11betaOH-P was greater than in rings previously incubated with either the corticosterone or 11betaOH-P alone (eg, response to 100 nmol/L phenylephrine in milligrams of force, mean+/-SE: corticosterone, 728+/-56, n=9; 11betaOH-P, 325+/-105, n=4; both, 1132+/-122, n=8; corticosterone versus both, P<.01). In contrast, the immediate contractile responses to phenylephrine and to angiotensin II were attenuated in rings exposed previously to both 11-dehydrocorticosterone and 11-keto-P. Thus, 11betaOH-P and 11-keto-P (and possibly structurally similar compounds) alter the vascular effects of glucocorticoids and may play a role in glucocorticoid-induced hypertension.

Chromosome 2 hypersensitivity and clonal development in murine radiation acute myeloid leukaemia

Acute myeloid leukaemias induced by ionizing radiation in mouse are characterized by chromosome (chr) 2 aberrations. While it is known that chr 2 aberrations form early and in abundance post-irradiation, unequivocal evidence for hypersensitivity of chr 2 in the first post-irradiation mitoses is lacking. Here it is established that chromosomal aberrations detected in bone marrow cells by chromosome painting are induced in all mice at an approximately 2-fold greater frequency in chr 2 by comparison with chrs 1 and 3 at 24 and 48 h following in vivo whole-body X-irradiation. Long-term follow up studies (to 15 months post-irradiation) indicated that chromosomal hypersensitivity is accounted for largely by the existence of hot-spots for aberration formation on sensitive chromosomes. Analysis of clonal developments suggested that chr 2 aberrant clones are selected for entry into the proliferating bone marrow cell compartment in preference to cells with other aberrations and that these clones in general have a higher proliferative potential. However, neither the induction of chr 2 aberrations nor the presence of a chr 2 aberrant clone specifically predict the development of AML in an individual irradiated mouse. Nonetheless these events or sub-groups of these events are necessary for AML development.

Interactions between pulse separation and pulse polarity order in cochlear implants

Interactions between pulse separation and pulse polarity order were examined using psychophysical studies of electrical detection thresholds in nonhuman primates. Subjects were trained using acoustic stimuli, then deafened in one ear and implanted with an electrode array for electrical stimulation of the cochlea. Threshold vs pulse separation functions for trains of biphasic electrical pulses were compared for constant and alternating leading phase polarity. When leading phase polarity was held constant, threshold vs pulse separation functions were nonmonotonic (U-shaped). Small polarity-dependent (cathodic vs anodic leading phase) differences in absolute thresholds were observed at long pulse separations, but function shape was independent of leading phase. When leading phase polarity alternated, there was a pronounced reduction in thresholds at short pulse separations (below about 1 ms), resulting in monotonically increasing threshold vs pulse separation functions. At long pulse separations, functions for alternating and constant polarity stimuli were similar. Polarity effects were most apparent for longer duration trains (20 pulses) at long pulse durations (1-2 ms/phase). For stimuli consisting of only two biphasic pulses, alternating polarity effects depended on whether cathodic or anodic phases were adjacent. The neural mechanisms underlying these effects probably include refractory properties and/or residual potentials.

Polymerase chain reaction for detection of Chlamydia trachomatis in conjunctival swabs

AIMS/BACKGROUND

Ocular Chlamydia trachomatis infection in the west occurs as opthalmia neonatorum, acquired from the mother, or adult paratrachoma which is also associated with current genital tract infection. Accurate rapid laboratory diagnosis facilitates management, but the relative merits of antigen detection or DNA amplification tests are unresolved.

METHODS

A polymerase chain reaction (PCR) test was developed which amplified part of the plasmid shared by all the serovars of C trachomatis. Conjunctival swabs were tested using an in house immune dot-blot test (IDBT) for chlamydial lipopolysaccharide antigen, a commercial direct fluorescent antibody (DFA) test for chlamydial elementary bodies, and the PCR (DNA extracted using guanidinium lysis buffer).

RESULTS

The PCR achieved a detection limit of 100 plasmid copies (10 elementary bodies). In a combined retrospective and prospective clinical evaluation, the PCR and IDBT gave identical results with 21 positive and 57 negative eye swabs. However, interpretation of the DFA test required meticulous examination of the stained smear, sometimes by two microscopists.

CONCLUSIONS

The PCR is likely to play an increasing role in the diagnosis of ocular C trachomatis infection because of its excellent sensitivity and specificity.

Successful diagnosis and management of cytomegalovirus carditis

Cytomegalovirus (CMV)-associated carditis in the immunosuppressed patient carries a 60% mortality. Underlying pathogenesis is poorly understood but may involve either direct viral invasion or autoimmune cardiac damage triggered in response to the infection. Specific anti-cytomegalovirus therapy and/or anti-inflammatory drugs have been shown to benefit in cases where an early diagnosis was established. We report an unusual case of endo-pericarditis which was temporally related to acute cytomegalovirus infection diagnosed by the immediate early antigen detection in cell culture on whole blood.

Influence of dietary sodium on the renal isoforms of 11 beta-hydroxysteroid dehydrogenase

Endogenous glucocorticoids are converted to their biologically inert 11-dehydroderivatives by isoforms of the enzyme 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD). The low-K(m), NAD(+)-dependent renal isoform (Type 2) identified in the distal nephron protects mineralocorticoid receptors from activation by endogenous glucocorticoids. The function of high-K(m), NADP(+)-dependent renal isoform (Type 1) is less well understood. Since glucocorticoids may modulate sodium transport in renal proximal tubules (PT), we hypothesized that Type 1 activity in this segment may be regulated by dietary Na(+)-11 beta-HSD activity was assessed in homogenates of canine PT by the conversion of cortisol to cortisone in the presence of NADP+ 200 microM. A high-Na+ diet for 4 days increased the Vmax 4-fold, with no change in the Type 1 K(m) (40 mEq/day Na+ diet: K(m) 0.959 microM, Vmax 3.40 pmoles/min/mg protein versus 150 mEq/day Na+ diet: K(m) 0.962 microM, Vmax 14.8 pmoles/min/mg protein). Type 1 mRNA also rose in the salt repleted animals. The high-Na+ diet produced no detectable change in the Type 2 isoform enzyme kinetics and mRNA level. No reverse oxo-reductase activity was noted with either renal isoform. Thus, renal Type 1 11 beta-HSD can be regulated by dietary Na+ independent of changes in the renal Type 2 isoform.

Selective inhibition of sheep kidney 11 beta-hydroxysteroid dehydrogenase isoform 2 activity by 5 alpha-reduced (but not 5 beta) derivatives of adrenocorticosteroids

We have previously reported that 5 alpha and 5 beta pathways of steroid metabolism are controlled in vivo by dietary Na+ and glycyrrhetinic acid, see Gorsline et al. 1988; Latif et al. 1990. The present investigations provide evidence supporting the suggestion that endogenous substances may regulate the glucocorticoid inactivating isoenzymes, 11 beta-HSD (hydroxysteroid dehydrogenase) 1 (liver) and 11 beta-HSD2 (kidney). The activity of 11 beta-HSD is impaired in essential hypertension, following licorice ingestion, and in patients with apparent mineralocorticoid excess where 11 beta-HSD2 is particularly affected. In all three conditions, excretion of the less common 5 alpha metabolites is elevated in urine. We now report on the differential abilities of a series of Ring A reduced (5 alpha and 5 beta) adrenocorticosteroid and progesterone metabolites to inhibit these isoenzymes. Using liver microsomes with NADP+ as co-factor (11 beta-HSD1), and sheep kidney microsomes with NAD+ as co-factor (11 beta-HSD2), we have systematically investigated the abilities of a number of adrenocorticosteroids and their derivatives to inhibit the individual isoforms of 11 beta-HSD. A striking feature is the differential sensitivity of the two isoenzymes to inhibition by 5 alpha and 5 beta derivatives. 11 beta-HSD1 is inhibited by both 5 alpha and certain 5 beta derivatives. 11 beta-HSD-2 was selectively inhibited only by 5 alpha derivatives: 5 beta derivatives were without inhibitory activity toward this isoform of 11 beta-HSD. These results indicate the importance of the structural conformation of the A and B Rings in conferring specific inhibitory properties on these compounds. In addition, we discuss the effects of additions or substitutions of other functional groups on the inhibitory potency of these steroid molecules against 11 beta-HSD1 and 11 beta-HSD2.

Kidney 11 beta-HSD2 is inhibited by glycyrrhetinic acid-like factors in human urine

We have previously shown that human urine contains substances that, like glycyrrhetinic acid, inhibit 11 beta-HSD1. We have named these substances "glycyrrhetinic acid-like factors" or GALFs. We now have found that human urine contains measurable quantities of both 11 beta(HSD1)- and 11 beta(HSD2)-GALF inhibitory substances. Both are markedly elevated in pregnancy. Their chemical and high-performance liquid chromatography (HPLC) characteristics suggest that several of the GALFs are steroidal. Large quantities of neutral 11 beta(HSD1)- and 11 beta(HSD2)-GALFs can be extracted directly from urine into ethyl acetate, yielding fraction EA1. Hydrolysis of the GALFs remaining in the aqueous phase by beta-glucuronidase markedly increases the total amounts of GALFs, with the majority now being ethyl acetate extractable (fraction EA2). These EA2 post-hydrolysis GALFs can be separated by HPLC resulting in at least six components with inhibitory activity against each isoenzyme. Only two GALF peaks are active against both 11 beta-HSD1 and 11 beta-HSD2. The others are peaks with specific 11 beta(HSD1)- and 11 beta(HSD2)-GALF inhibitory activity. The GALFs in the same posthydrolysis EA2 extract are also inhibitory toward the 11 beta-HSD1 that is present in vascular smooth muscle where they may play a role in the mechanisms controlling blood pressure. We have also found that 11 beta-HSD2 is selectively inhibited by 5 alpha- (but not by 5 beta-) reduced steroids. GC-MS analysis of the 11 beta(HSD2)-GALFs in EA2 is now being performed to determine whether this group includes 3 alpha,5 alpha-ring A-tetrahydro-reduced derivatives of steroids.

Effects of licorice derivatives on vascular smooth muscle function

Vascular smooth muscle contains a bidirectional form of the enzyme 11beta-hydroxysteroid dehydrogenase (11beta-HSD) which can inactivate (dehydrogenase) endogenous circulating glucocorticoids (GCs) or activate (oxo-reductase) 11-dehydro-metabolites by their conversion back to the parent steroid. Enzyme direction in vascular smooth muscle (VSM) has potential physiological consequences since GCs may enhance the response to known vasoconstrictors. We determined that carbenoxolone is a competitive inhibitor of 11beta-HSD contained in VSM cells with a lower Ki for forward dehydrogenase reaction (0.02 microM) compared to the oxo-reductase reaction (0.41 microM). To test whether changes in enzyme directional activity can affect the contractile response, aortae from adrenally intact Sprague Dawley rats were removed and sectioned into 2.5 mm rings. Rings were incubated with corticosterone 10 nM plus carbenoxolone (CBX) 10 microM (a concentration well above the Ki for both the dehydrogenase and oxo-reductase reaction) for 24 hrs. These rings showed an enhanced dose dependent contractile response to phenylephrine (PE) 0.01 microM(-1) microM and to angiotensin II 1 microM compared to rings incubated with corticosterone alone, CBX alone, or controls: [e.g. response to PE 1 microM in mg of contractile force, mean +/- SE: corticosterone plus CBX 1495 +/- 162 (n=10) vs corticosterone 1039 +/- 64 (n=9), p<0.05]. Aortic rings preincubated with 11-dehydrocorticosterone 10(-7)M and CBX 10 microM displayed a decreased contractile response compared to 11-dehydrocorticosterone alone. Thus in situ glucocorticoid metabolism is important in mediating the constrictor responses of vascular tissue.

Endogenous 11 beta-hydroxysteroid dehydrogenase inhibitors and their role in glucocorticoid Na+ retention and hypertension

11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) metabolizes active glucocorticoids to their inactive 11-dehydro products and protects renal mineralocorticoid receptors from the high circulating levels of endogenous glucocorticoids. 11 beta-HSD has been suggested to be important not only in the control of renal sodium retention but also blood pressure. We had previously shown that 11 alpha- and 11 beta-hydroxyprogesterone (11 alpha- and 11 beta-OHP) were (I) potent inhibitors of 11 beta-HSD (Isoforms 1 and 2) activity in vitro, (ii) able to confer mineralocorticoid (MC) activity upon corticosterone (B) in vivo and (iii) hypertensinogenic when chronically infused into Sprague-Dawley (SD) rats. In addition we also showed that 3 alpha,5B-tetrahydroprogesterone (3 alpha,5B-THP) and chenodeoxycholic acid (CDCA) were potent inhibitors of 11 beta-HSD1 activity but not 11 beta-HSD2 activity, however, these substances were still able to confer MC activity upon B in the adrenalectomized rat. To assess the possible blood pressure modulating effects of 3 alpha,5B-THP and CDCA we have now infused these substances into intact SD rats continuously for 14 days. Both 3 alpha,5B-THP and CDCA caused a significant elevation in blood pressure within seven days, an effect that persisted throughout the 14-day infusion. These results show that both 3 alpha,5B-THP and CDCA are hypertensinogenic in the rat and that the inhibition of either 11 beta-HSD2 or 11 beta-HSD1 activity by endogenous progesterone metabolites and CDCA may be involved in the pathology of hypertension.

Role of telomeric sequences in murine radiation-induced myeloid leukaemia

A previous study indicated that a highly inbred CBA/H mouse colony contained four genotypic variants for telomere-like repeat (TLR) sequence arrays and that one variant subpopulation that constituted 20% of the colony contributed the vast majority (> 90%) of radiation-induced acute myeloid leukaemias (AMLs). Through screening of a satellite CBA/H colony and rescreening of the original colony, we show that, whereas germline telomere sequence polymorphism is frequent in CBA/H mice, there is no genetic link between a specific TLR locus variant and susceptibility to AML. Studies on telomere-hybridising fragments between 200 bp and 150 kb revealed that the germline telomere mutation frequency was highest for restriction fragments > 50 kb. The hypervariability of these high-molecular-weight fragments resulted in each CBA/H mouse from the highly inbred colony having a different genotype. Although it was not possible to ascribe a specific somatic telomere mutation to AML development, telomere rearrangements were common in induced AMLs. Some terminal telomere-hybridising restriction fragments were shortened in AML samples in comparison with normal tissue, but, insofar as the reduction in size was relatively small, it seems unlikely that telomere erosion is a major contributor to the molecular pathology of murine radiation-induced AML.

Detection of herpes simplex virus DNA in donor cornea culture medium by polymerase chain reaction

AIMS/BACKGROUND

Herpes simplex virus (HSV) may establish latent infection in the cornea and therefore be transmissible by corneal transplantation. Monitoring of donor cornea culture medium was evaluated for HSV infection.

METHODS

HSV was sought using virus isolation in cell culture, and its DNA was amplified to detectable levels using the polymerase chain reaction (PCR).

RESULTS

Virus isolation in cell culture was negative on neat, cell pellet, and cell free supernatant prepared from the spent culture media of 80 corneas. Three cell pellets (3.8%) were positive for HSV DNA. The PCR positive culture negative results might have reflected latent rather than active HSV infection of the cornea. Post transplant follow up of the three recipients of corneas with HSV PCR positive organ culture media revealed no evidence of HSV induced eye disease or primary graft failure.

CONCLUSION

Screening of corneal culture medium for HSV by virus culture or for HSV DNA by PCR could not be recommended.

Comparison of primer sets for detection of fecal and ocular adenovirus infection using the polymerase chain reaction

Adenoviruses of subgenus F (types 40 and 41) cause infantile gastroenteritis and adenoviruses principally of types 1-7 are found in feces during respiratory or generalized infections. Adenoviruses (mostly types 3, 4, 8, 19, or 37) are also linked with follicular or epidemic conjunctivitis. The diagnostic efficiency of the polymerase chain reaction (PCR) for adenoviruses was assessed using genus-reactive primers H1 and H2 or JCH1 and JCH2 or subgenus F-specific primers F1a and F2a. With diarrheal stool specimens containing subgenus F adenoviruses, F1a/F2a PCR achieved at least as high a positivity rate (75/76 [99%]) as electron microscopy (72/76 [95%]) and was more sensitive than polyclonal antibody-based immune electron microscopy (IEM) for subgenus identification (75/76 [99%] vs. 66/76 [87%], P = 0.008). Twenty-three subgenus F strains untypeable by monoclonal antibody-based IEM were typed as 40 (n = 4) or 41 (n = 19) by Hha I digestion of the PCR product. The genus-reactive primer pairs provided DNA amplification assays of generally equal efficiency on conjunctival swab specimens though possible nucleic acid degradation in DNA extracts during storage could have meant that JCH1/JCH2 PCR was truly the more sensitive. The use of either genus-reactive primer set on fecal specimens cannot be recommended because, although the positivity rates with subgenus F PCR positive specimens were high (70/75 [93%] for H1 and H2, 14/15 [93%] for JCH1 and JCH2), the detection rates were disappointing with similar specimens yielding nonsubgenus F adenoviruses.

11 alpha- and 11 beta-hydroxyprogesterone, potent inhibitors of 11 beta-hydroxysteroid dehydrogenase, possess hypertensinogenic activity in the rat

The progesterone derivatives 11 alpha- and 11 beta-hydroxyprogesterone are potent inhibitors of 11 beta-hydroxysteroid dehydrogenase (isoforms 1 and 2) in vitro and can confer mineralocorticoid activity on corticosterone in the rat in vivo. 11 beta-Hydroxysteroid dehydrogenase metabolizes active glucocorticoids to their inactive 11-dehydro products and protects renal mineralocorticoid receptors from the high circulating levels of endogenous glucocorticoids. 11 beta-Hydroxysteroid dehydrogenase has been suggested to be important not only in the control of renal sodium retention but also of blood pressure. To assess the possible blood pressure-modulating effects of 11 alpha- and 11 beta-hydroxyprogesterone, we infused these substances into both intact and adrenalectomized Sprague-Dawley rats continuously for 14 days. Both 11 alpha- and 11 beta-hydroxyprogesterone caused a significant elevation in blood pressure within 3 days, an effect that persisted throughout the 14-day infusion. The hypertensive effects of 11 alpha-hydroxyprogesterone were abolished by adrenalectomy and significantly attenuated when 11 alpha-hydroxyprogesterone was infused together with the specific mineralocorticoid receptor antagonist RU28318. In an additional series of experiments, 11 alpha-hydroxyprogesterone significantly amplified the hypertensive effects of corticosterone in adrenalectomized spontaneously hypertensive rats but had no effects by itself in this experimental animal. These results demonstrate that both 11 alpha- and 11 beta-hydroxyprogesterone are potently hypertensinogenic in the rat and that this activity depends on an intact adrenal and at least in part on the activation of mineralocorticoid receptors. 11 beta-Hydroxyprogesterone, and similar endogenous progesterone metabolites that inhibit 11 beta-hydroxysteroid dehydrogenase, may be involved in the pathology of certain hypertensive states.

Polymerase chain reaction for rapid diagnosis of respiratory adenovirus infection

Endemic (type 1, 2, 5 and 6) and epidemic (type 3, 4 and 7) respiratory adenovirus infections are associated with upper respiratory tract symptoms, pharyngoconjunctival fever, and pneumonia. Improved methods of diagnosis are needed, particularly in immunocompromized patients. We examined 93 throat swabs or nasopharyngeal aspirates from patients with acute respiratory disease using virus isolation and an adenovirus-specific polymerase chain reaction (PCR) based on consensus primers H1 and H2 derived from the hexon region DNA sequences of serotypes 2 and 5. Specimens which yielded viruses other than adenovirus in cell culture (n = 23) or which were negative for infectious viruses (n = 25) were negative in the PCR. The sensitivity of DNA amplification was 76% (34/45) in comparison with virus culture, being markedly lower with subgenus B (types 3 and 7) strains than with subgenus C (type 1, 2, 5 and 6) isolates (8/16 (50%)) vs. 26/28 (93%). P = 0.004) despite the use of a low annealing temperature to maximize detection of adenoviruses belonging to subgenera other than C. Of the 11 samples falsely negative in a single-round PCR but yielding adenovirus type 1 (n = 1), type 2 (n = 1). type 3 (n = 7), type 7 (n = 1), or untyped isolates (n = 1) in cell culture, nine (82%) gave positive results after nested DNA amplification. Possible approaches to further improving the performance of adenovirus PCR with respiratory specimens are discussed.

Multiplex polymerase chain reaction for adenovirus and herpes simplex virus in eye swabs

Adenoviruses and herpes simplex virus (HSV) can cause clinically indistinguishable episodes of acute eye disease. Adenovirus infection is associated with nosocomial outbreaks and HSV may result in episodes of recurrent ocular inflammation. In a comparison of multiplex PCR for the two viral DNAs and virus isolation in cell culture, identical results were obtained for 18 of 20 specimens (positive for adenovirus in 5, HSV in 5, and negative in 8). One specimen was falsely negative for each viral DNA. Inclusion of human beta-globin primers in the adenovirus-HSV reaction was precluded by a consequential 10--100-fold reduction in sensitivity for the two viral targets and by the failure of beta-globin DNA amplification at the annealing temperature (45 degrees C) required to ensure detection of adenoviruses of serotypes 7 and 11 with the selected adenovirus primers. A single-target beta-globin PCR gave positive results with 19 of the 20 specimens prepared by treatment with proteinase K lysis buffer, indicating the effectiveness of this simple DNA extraction procedure. Nonetheless, the availability of effective antiviral therapy for HSV made monitoring for extraction failure using human primers crucial to avoid false-negative results for HSV DNA. Adenovirus-HSV PCR has considerable potential for the rapid diagnosis of viral eye disease particularly if beta-globin primers can be included in the reaction.

Pathogenesis of calciphylaxis: study of three cases with literature review

Calciphylaxis is characterized by ischemic necrosis, primarily of skin. The early phase of the ischemia has not been studied, and the pathogenesis is uncertain. In this study of early calciphylaxis, the vessels responsible for the ischemia seem to be within the material available for microscopic review, and the various stenosing vascular lesions are quantified. A distinctive and previously described small vessel calcification with superimposed endovascular fibrosis is most common, and is much more frequent than two other lesions proposed to cause the ischemia (thrombosis and global calcific obliteration). The calcified stenotic vessels average 100 microns in diameter. Calcification precedes the endovascular fibrosis. Vessels with early endovascular fibroblastic activation are found statistically to be strongly associated with the presence of a giant cell reaction. This endovascular giant cell reaction has not been previously described in calciphylaxis. Two additional cases show similar findings. The histology resembles the reaction to calcium in a variety of other extraosseous calcification syndromes, for example, pseudogout, as if calciphylaxis were an endovascular form of calcium crystal-induced inflammatory disease. The literature is reviewed, and the clinicopathologic, radiographic, and therapeutic implications are discussed.