Mutation analysis in Chariot-Marie Tooth disease type 1: point mutations in the MPZ gene and the GJB1 gene cause comparable phenotypic heterogeneity

Charcot-Marie-Tooth disease type 1 (CMT1) is a demyelinating peripheral neuropathy most commonly caused by a DNA duplication on chromosome 17p11.2 including the peripheral myelin protein 22 (PMP22). Point mutations in the myelin protein zero gene (MPZ) and gap junction protein, beta-1 gene (GJB1) are also found in association with CMT1 or the subclass of CMT type X (CMTX), respectively. Recently point mutations in these genes have been found in patients showing the axonal variant of CMT, CMT type 2 (CMT2). We here describe the clinical and electro-physiological findings caused by two novel and two recently described MPZ mutations and six GJB1 mutations. Different MPZ and GJB1 mutations were associated with different grades of severity in CMT1 and CMTX. The novel MPZ Glu141st op mutation was associated with the axonal CMT2. We conclude that the clinical and electrophysiological heterogeneity among CMT patients carrying point mutations in MPZ and GJB1 is similar. Thus for clinical purposes CMT1 and CMT2 patients should be screened for mutations in these two genes after duplication on chromosome 17p11.2 has been excluded as the disease causing mutation.

Reducing risk by improving standards of intrapartum fetal care

Confidential Enquiries into Stillbirths and Deaths in Infancy (CESDI) have pointed to a high frequency of suboptimal intrapartum fetal care of a kind that, in the event of an adverse outcome, is hard to defend in court. In an effort to minimize liability, various strategies were applied in a district hospital labour ward--guidelines, cyclical audit, monthly feedback meetings and training sessions in cardiotocography (CTG). The effects of these interventions on quality of care was assessed by use of the CESDI system in all babies born with an Apgar score of 4 or less at 1 min and/or 7 or less at 5 min. 540 babies (4.3%) had low Apgar scores, and neither the percentage nor gestational age differed significantly between audit periods. In the baseline audit, care was judged suboptimal (grade II/III) in 14 (74%) of 19 cases, and in the next four periods it was 23%, 27%, 27% and 32%. In the latest audit period, after further educational interventions, it was 9%. Many of the failures to recognize or act on abnormal events were related to CTG interpretation. After the interventions there was a significant increase in cord blood pH measurement. There were no differences between audit periods in the proportion of babies with cord pH < 7.2. These results indicate that substantial improvements in quality of intrapartum care can be achieved by a programme of clinical risk management.

Management of massive postpartum haemorrhage: use of a hydrostatic balloon catheter to avoid laparotomy

Postpartum haemorrhage remains a significant complication of childbirth in the UK and worldwide. The most common cause of postpartum haemorrhage is uterine atony, but placent accreta is becoming more frequent. In these situations tamponade may be required. The successful use of the inflated stomach balloon (300ml) of a Sengstaken-Blakemore tube has been reported previously. We describe an innovative method of 'tamponade' which is simple and effective, using the Rüsch urological hydrostatic balloon catheter. In two cases of failed medical therapy for PPH, where the catheter has been tried, further surgical interventions have been avoided.

Human Soluble Guanylate Cyclase: Functional Expression, Purification and Structural Characterization

Soluble guanylate cyclase is an enzyme that catalyzes formation of cGMP from GTP and is a member of the nucleotide cyclase family of enzymes. sGC is a receptor for endogenous and exogenous nitric oxide and is activated several-fold upon its binding, constituting a core enzyme in the nitric oxide signal transduction pathway. cGMP generated by sGC is an important second messenger that regulates activity of several enzymes triggering such important physiologic reactions as vasodilation, smooth muscle relaxation and platelet aggregation. We report here the functional expression of the human isoform of soluble guanylate cyclase in HighFive insect cells using a baculovirus expression system. Highly active recombinant protein was obtained without heme reconstitution or supplementation of the cell growth medium and the level of protein expression was found to be heavily affected by the composition of the growth medium. We have successfully purified highly active sGC (sp act up to 940 nmol/min/mg) from adherent cultures using a three-column, 1-day procedure. The UV-Vis spectrum of the isolated protein shows a Soret band at 431 nm, consistent with a histidine-ligated, 5-coordinate heme as previously reported. Far UV CD spectroscopy, intrinsic tryptophan fluorescence, fluorescence of the hydrophobic dye bis-ANS, size-exclusion chromatography, and small angle X-ray scattering (SAXS) were used to characterize the structural properties of the purified sGC. We used two hierarchical neural network methods to predict the secondary structure of sGC and found it to be consistent with the observed CD spectrum of sGC.

The natural history of Hendra and Nipah viruses

Pteropid bats (flying foxes), species of which are the probable natural host of both Hendra and Nipah viruses, occur in overlapping populations from India to Australia. Ecological changes associated with land use and with animal husbandry practices appear most likely to be associated with the emergence of these two agents.

[Histological and clinical forms of the eosinophilic cellulitis]

BACKGROUND

Wells' syndrome is characterized by clinical features of cellulitis and a histological picture of eosinophilic infiltrate of the dermis with some "flame" figures.

PATIENTS AND METHODS

The clinical and histological features of nine patients with Wells' syndrome seen from 1988 to 1998 were retrospectively reviewed.

RESULTS

The clinical features of the nine patients (five men and four women) were urticaria (n=1), cellulitis (n=2), annular plaques (n=3), vesiculo-bullous lesions (n=2) and edema of the face with nodules of the conjunctiva (n=1). Histological examination of skin biopsies showed an eosinophilic infiltrate of the dermis associated with some "flame" figures in all cases. The infiltrate was located in the superficial or deep dermis in accordance with the different clinical features. One patient developed a non Hodgkin lymphoma and presented successively: a Wells' syndrome, a leucocytoklastic vasculitis and a Sweet's syndrome. Numerous treatment were used: topical corticosteroids, H1-antihistamines, dapsone and systemic corticosteroids. Two patients relapsed after treatment withdrawal.

DISCUSSION

This study demonstrated a wide polymorphism of the clinical and histological features of Wells' syndrome. The clinical features seem to depend on the location of the dermal infiltrate, suggesting the existence of a spectrum of eosinophilic dermatoses, like in neutrophilic dermatoses. The successive occurrence of vasculitis, Wells' syndrome and Sweet'syndrome in a patient suggests an overlap between these diseases. Systemic corticosteroids are the most effective treatment, but may lead to a corticosteroid dependence.

Association between early sexual abuse and adult HIV-risky sexual behaviors among community-recruited women

OBJECTIVE

The first purpose was to determine whether sexual abuse involving penetration that occurred in childhood only, adolescence only, or both childhood and adolescence differently impacted whether community-recruited women had ever traded sex for money or drugs, their number of recent sex partners, and the number of times they had engaged in recent unprotected sex. The second purpose was to assess the mediating effects of adulthood rape, recent drug use, and recent sex with an injection drug user on these three HIV-risky sexual behaviors.

METHOD

Women (n = 1,490) recruited from three US sites were questioned about their childhood and/or adolescent sexual abuse histories, adulthood rape experiences, recent drug use, and adult HIV-risky sexual behaviors via structured interviews.

RESULTS

One-third of the women reported having experienced sexual abuse involving penetration in childhood and/or adolescence. Overall, regression analyses indicated a significant relationship between early sexual abuse and adult risky behaviors; rape in adulthood mediated this relationship for all three HIV-risky behaviors. Abuse that occurred in childhood only and abuse that occurred in both childhood and adolescence had a stronger impact on later risky behaviors than did abuse that occurred in adolescence only.

CONCLUSIONS

Because childhood constitutes a critical period in individuals' sexual, social, and personal development, sexual abuse precipitated during this time may distort women's constructions of sex and sexuality. Women abused in childhood may therefore engage in HIV-risky sexual behaviors to a greater extent than women abused in adolescence as a result of these disruptions to their development. Rape in adulthood appears to intensify the effects of early sexual abuse,

Paracrine mechanisms of mouse mammary ductal growth

Ductal growth during puberty is stimulated by estrogens, which elicit their effects via specific estrogen receptors, ER alpha and ER beta. Analysis of mice with targeted disruption of ER alpha or ER beta has emphasized the importance of ER alpha in mammary gland development. In the mouse mammary gland, ER alpha are expressed in both epithelial and stromal cells (Kurita and Cunha, unpublished), which raises the possibility that the growth and morphogenetic effects of estrogen could be mediated via either epithelial or stromal ER. The aim of this paper is to review the role of epithelial versus stromal ER in mammary ductal-alveolar growth to assess the importance of paracrine mechanisms.

Extracts from "Clinical evidence": Athlete's foot and fungally infected toenails

Definition Athlete's foot is a cutaneous fungal infection that causes the skin to itch, flake, and fissure. Nail involvement is characterised by ungual thickening and discoloration.

Evidence that epithelial and mesenchymal estrogen receptor-alpha mediates effects of estrogen on prostatic epithelium

In combination with androgens, estrogens can induce aberrant growth and malignancy of the prostate gland. Estrogen action is mediated through two receptor subtypes: estrogen receptors alpha (ERalpha) and beta (ERbeta). Wild-type (wt) and transgenic mice lacking a functional ERalpha (alphaERKO) or ERbeta (betaERKO) were treated with the synthetic estrogen diethylstilbestrol (DES). DES induced prostatic squamous metaplasia (SQM) in wt and betaERKO but not in alphaERKO mice, indicating an essential role for ERalpha, but not ERbeta, in the induction of SQM of prostatic epithelium. In order to determine the respective roles of epithelial and stromal ERalpha in this response, the following tissue recombinants were constructed with prostatic epithelia (E) and stroma (S) from wt and ERKO mice: wt-S+wt-E, alphaERKO-S+alphaERKO-E, wt-S+alphaERKO-E, and alphaERKO-S+wt-E. A metaplastic response to DES was observed in wt-S+wt-E tissue recombinants. This response to DES involved multilayering of basal epithelial cells, expression of cytokeratin 10, and up-regulation of the progesterone receptor. Tissue recombinants containing alphaERKO-E and/or -S (alphaERKO-S+alphaERKO-E, wt-S+alphaERKO-E, and alphaERKO-S+wt-E) failed to respond to DES. Therefore, full and uniform epithelial SQM requires ERalpha in the epithelium and stroma. These results provide a novel insight into the cell-cell interactions mediating estrogen action in the prostate via ERalpha.

Identification and characterization of a Drosophila nuclear proteasome regulator. A homolog of human 11 S REGgamma (PA28gamma )

We report the cloning and characterization of a Drosophila proteasome 11 S REGgamma (PA28) homolog. The 28-kDa protein shows 47% identity to the human REGgamma and strongly enhances the trypsin-like activities of both Drosophila and mammalian 20 S proteasomes. Surprisingly, the Drosophila REG was found to inhibit the proteasome's chymotrypsin-like activity against the fluorogenic peptide succinyl-LLVY-7-amino-4-methylcoumarin. Immunocytological analysis reveals that the Drosophila REG is localized to the nucleus but is distributed throughout the cell when nuclear envelope breakdown occurs during mitosis. Through site-directed mutagenesis studies, we have identified a functional nuclear localization signal present in the homolog-specific insert region. The Drosophila PA28 NLS is similar to the oncogene c-Myc nuclear localization motif. Comparison between uninduced and innate immune induced Drosophila cells suggests that the REGgamma proteasome activator has a role independent of the invertebrate immune system. Our results support the idea that gamma class proteasome activators have an ancient conserved function within metazoans and were present prior to the emergence of the alpha and beta REG classes.

[Hemophagocytic syndrome and metastatic melanoma: 3 cases]

BACKGROUND

Macrophage activation syndrome was initially described during viral infections in immunocompromised patients. Since the original report, many diseases have been found to be associated with macrophage activation syndrome. Lymphoproliferative disorders have been more frequently reported to be associated with macrophage activation syndrome than solid tumors. We herein report three cases of macrophage activation syndrome in patients with metastatic malignant melanoma.

CASE-REPORTS

Two young 32 and 40 year-old men with a liver metastatic malignant melanoma and a 62 year-old woman with a polymetastatic malignant melanoma presented a sudden deterioration of general health with hyperthermia and biological abnormalities: liver cytolysis, leucocytosis, thrombocytopenia, hypertriglyceridaemia. A fatal clinical outcome occurred rapidly despite corticotherapy and/or chemotherapy. For the first two patients the macrophage activation syndrome diagnosis was delayed because of the similarities of macrophage activation syndrome and metastatic malignant melanoma symptoms.

DISCUSSION

The diagnosis of macrophage activation syndrome in patients with metastatic malignant melanoma may be difficult because of the similarities between clinical features of macrophage activation syndrome and those of metastatic malignant melanoma. Hypertriglyceridaemia is present in 60 p. 100 of macrophage activation syndrome and should lead to process a bone marrow aspirate. The search for a triggering infection should be systematically carry out because it is implicated in more than half of macrophage activation syndrome whatever the associated disease may be: neoplasia, autoimmune disease. The pathogenesis of macrophage activation syndromes occurring in patients with metastatic cancer remains unexplained. Treatment of macrophage activation syndrome is not unanimously established and usually consists in the treatment of the associated condition as well as a corticosteroid and/or an immunosuppressive treatment regimens. Prognosis of macrophage activation syndrome is usually poor especially when it is associated with a neoplasia since a fatal outcome occurs in 40 to 60 p. 100 of cases.

The interaction of titin and alpha-actinin is controlled by a phospholipid-regulated intramolecular pseudoligand mechanism

The assembly of stable cytoskeletal structures from dynamically recycled molecules requires developmental and spatial regulation of protein interactions. In muscle, titin acts as a molecular ruler organizing the actin cytoskeleton via interactions with many sarcomeric proteins, including the crosslinking protein alpha-actinin. An interaction between the C-terminal domain of alpha-actinin and titin Z-repeat motifs targets alpha-actinin to the Z-disk. Here we investigate the cellular regulation of this interaction. alpha-actinin is a rod shaped head-to-tail homodimer. In contrast to C-terminal fragments, full-length alpha-actinin does not bind Z-repeats. We identify a 30-residue Z-repeat homologous sequence between the actin-binding and rod regions of alpha-actinin that binds the C-terminal domain with nanomolar affinity. Thus, Z-repeat binding is prevented by this 'pseudoligand' interaction between the subunits of the alpha-actinin dimer. This autoinhibition is relieved upon binding of the Z-disk lipid phosphatidylinositol-bisphosphate to the actin-binding domain. We suggest that this novel mechanism is relevant to control the site-specific interactions of alpha-actinin during sarcomere assembly and turnover. The intramolecular contacts defined here also constrain a structural model for intrasterical regulation of all alpha-actinin isoforms.

Safety and costs of initiating angiotensin converting enzyme inhibitors for heart failure in primary care: analysis of individual patient data from studies of left ventricular dysfunction

OBJECTIVE

To estimate the costs and consequences of diagnosing symptomatic heart failure with left ventricular systolic dysfunction and initiating angiotensin converting enzyme inhibitors in primary care.

DESIGN

Analysis of individual patient data from studies of left ventricular dysfunction (SOLVD) to identify complications during test dose and titration phases.

SETTING

Two randomised controlled trials in secondary care.

PARTICIPANTS

7487 patients taking a test dose of enalapril at enrolment to the treatment and prevention trials; 2569 patients with clinical signs of heart failure and established left ventricular dysfunction entered the treatment trial.

MAIN OUTCOME MEASURES

Discontinuation during the test dose period. Discontinuation or reduction of dose during the first year of treatment for heart failure. Costs of diagnosis and titration of treatment.

RESULTS

During the test dose phase, 585 patients (7.8%) reported side effects; 136 (1.8%) of these discontinued because of severe side effects. During the titration phase, compared with placebo, enalapril was associated with an increased risk of dose reduction due to hypotension (odds ratio 2.09, 95% confidence interval 1.15 to 3.82). However, overall, there was no difference in the rates of side effects leading to dose reduction or withdrawal between the enalapril and placebo groups. The costs of diagnosing heart failure with left ventricular systolic dysfunction and initiating and titrating an angiotensin converting enzyme inhibitor in primary care are pound300 to pound400.

CONCLUSIONS

Treatment with angiotensin converting enzyme inhibitors can be safely started for patients with heart failure and left ventricular systolic dysfunction in primary care.

Sex hormone-induced carcinogenesis in Rb-deficient prostate tissue

The retinoblastoma (Rb) gene product is a prototypic tumor suppressor. Mice lacking the Rb gene are not viable and die in utero at approximately 13 days of gestation. In this study, we have rescued Rb-/- prostates by grafting pelvic organ rudiments from Rb-/- mouse embryos under the renal capsule of adult male nude mouse hosts. Grafts of embryonic pelvic organs developed into functional prostatic tissue. Some of the prostatic tissue generated was further used to construct chimeric prostatic tissue recombinants by combining wild-type rat urogenital mesenchyme (rUGM) with Rb-/- and Rb+/+ prostatic epithelium (PRE). The tissue recombinants were grown as subcapsular renal grafts and treated from the time of grafting with Silastic capsules containing 25 mg of testosterone plus 2.5 mg of estradiol. During 5-8 weeks of hormone treatment, rUGM+Rb+/+PRE tissue recombinants developed prostatic hyperplasia, whereas PRE in rUGM+Rb-/-PRE tissue recombinants developed hyperplasia, atypical hyperplasia, and carcinoma. During carcinogenesis in rUGM+Rb-/-PRE tissue recombinants, prostatic epithelial cells of the basal lineage disappeared, whereas the luminal cells underwent carcinogenesis. Epithelial E-cadherin almost totally disappeared. In all cases, epithelial PCNA labeling was elevated in tissue recombinants containing Rb-/- versus Rb+/+ epithelium. These epithelial changes were associated with almost total loss of smooth muscle cells in the stroma. In contrast, in untreated hosts rUGM+Rb+/+PRE tissue recombinants developed normally, and rUGM+Rb-/-PRE tissue recombinants developed mild epithelial hyperplasia. The results of this study demonstrate that Rb-/- prostatic tissue can be rescued from embryonic lethal mice and used to test its susceptibility to hormonal carcinogenesis. Deletion of the Rb gene predisposes prostatic epithelium to hyperplasia and increases proliferative activity Susceptibility to hormonal carcinogenesis in response to exogenous testosterone + estradiol is manifested in the progression from atypica hyperplasia to carcinoma. Thus, these findings demonstrate that the absence of the Rb tumor suppressor gene may predispose prostatic epithelial cells to carcinogenesis. Rescue of organs from Rb-/- embryos not only provides an opportunity to analyze the Rb gene pathway in the development and progression of prostate cancer but also provides an opportunity for specifically evaluating the role of the Rb pathway in development and carcinogenesis in other organs, such as the mammary gland and colon. Because rUGM greatly stimulates prostatic epithelial proliferation, the tissue recombinant model is a particularly useful tool for assessing the functional role of other genes in prostatic carcinogenesis through use of the appropriate transgenic or gene knockout mice.

Predictive value of pharmacological activity for the relative efficacy of antidepressant drugs. Meta-regression analysis

BACKGROUND

There is uncertainty about the contribution of specific pharmacological properties to the efficacy of antidepressants.

AIMS

To assess whether specific pharmacological characteristics of alternative antidepressants resulted in altered efficacy compared to that of selective serotonin reuptake inhibitors in the treatment of major depression.

METHOD

Meta-regression analysis of randomised trials that compare treatment with a selective serotonin reuptake inhibitor and an alternative antidepressant.

RESULTS

One-hundred-and-five randomised trials were included. None of the factors identified a priori predicted a statistically significant improvement in outcome across the trials.

CONCLUSIONS

This analysis does not provide evidence that antidepressants acting at more than one pharmacological site differ in efficacy from drugs selective for serotonin reuptake in the treatment of major depression.

Treatment of an acyclovir and foscarnet-resistant herpes simplex virus infection with cidofovir in a child after an unrelated bone marrow transplant

Herpes simplex virus (HSV) causes serious problems in immuno-compromised patients such as those receiving a bone marrow transplant (BMT) for a hematological malignancy. Resistance to acyclovir (ACV) is a growing major concern. Foscarnet is a non-thymidine kinase-dependent agent, but the emergence of ACV and foscarnet-resistant HSV requires a new therapeutic approach. We describe a girl treated with cidofovir for a life-threatening ACV-resistant HSV infection after an unrelated BMT for a relapse of an acute myeloblastic leukemia (AML).

PMP22 Thr118Met is not a clinically relevant CMT1 marker

It is controversial if peripheral myelin protein 22 gene (PMP22) Thr118Met represents a functionally irrelevant polymorphism or, since hemizygosity for this variant has been found in two patients with Charcot-Marie-Tooth disease type 1 (CMT1 patients), it can act as a recessive CMT1 mutation. To shed further light on this variant and its diagnostic value we searched for carriers in 1018 individuals from the German general population, in 104 probands with hereditary neuropathy with liability to pressure palsies (HNPP) who were carriers of the 1.5-Mb deletion frequently associated with this disorder, in 187 patients with the 1.5-Mb duplication, and in 22 patients with a CMT1 phenotype who did not have any detectable anomaly in the PMP22 gene. Using allele-specific PCR we identified 14 [allele frequency (AF)=0.007] in the German general population, one (AF=0.01) in the HNPP group and six (AF=0.016) and two (AF=0.05) carriers of the PMP22 Thr118Met mutation in the CMT1 groups with and without gene defect. Carriers from all groups showed nerve conduction velocities which did not differ from typical values for these groups. We conclude that the hemizygous occurrence of the 118Met allele does not usually cause CMT1. Because of previous reports on its association with disease, and because its allele product shows abnormalities in in vitro expression systems, it seems possible that this mutation, together with yet unidentified factors, predisposes to CMT1. Alternatively, previously reported disease associations occurred by chance, and the 118Met allele causes biochemical abnormalities irrelevant for CMT1 formation. In either case this mutation is not a clinically relevant disease marker.

Echoplanar imaging in GI clinical practice: assessment of gastric emptying and antral motility in four patients

Gastric emptying, frequency of antral contractions, and speed of antral contraction propagation were assessed in four patients using echoplanar imaging techniques. The results obtained and their impact on the diagnosis and management of the patients are presented and discussed. This shows that echoplanar evaluation of gastric function is noninvasive, well-tolerated by patients, detects clinically relevant abnormalities, and has the potential of becoming a valuable examination in the clinical gastrointestinal practice.