Evaluation of liquid-based cytology in cervical screening of high-risk populations: a split study of colposcopy and genito-urinary medicine populations

A split study evaluated the ThinPrep(R) PapTesttrade mark (TP; Cytyc Corp., Boxborough, MA) compared with current methodologies of cervical cytology in two high-risk cohorts. One thousand, three hundred cases from a colposcopy clinic and a genito-urinary medicine outpatient clinic were examined. The TP reported increased detection of all grades of dyskaryosis (mild, moderate and severe; + 4.5%) and a decrease in borderline and unsuitable cases (- 4.9%). Four cases of high-grade dyskaryosis (moderate or severe) were detected only using the TP, while an additional four cases classified as high-grade dyskaryosis with the TP were reported as borderline by our conventional methods. The split-study finding of increased sensitivity with the TP provides for improved clinical management of patients in our high-risk cohorts.

Chronic effects of ACE-inhibition (quinapril) and angiotensin-II-type-1 receptor blockade (losartan) on atrial natriuretic peptide in brain nuclei of rats with experimental myocardial infarction

Alterations of the central nervous system may be important for imbalance of cardiovascular and fluid regulation in heart failure. The central renin-angiotensin and atrial natriuretic peptide (ANP) systems act as mutual antagonists. The effects of angiotensin converting enzyme (ACE) inhibition (quinapril, 6 mg/kg/day) and angiotensin II type 1 (AT1) receptor blockade (losartan, 10 mg/kg/day) on ANP levels in 18 selected, microdissected brain nuclei were determined in sham-operated rats and rats with left ventricular dysfunction 8 weeks after myocardial infarction (MI). Plasma ANP tended to increase in MI rats and was further increased by quinapril. ANP was decreased in 12 brain areas of MI rats. ANP concentration was also significantly decreased by quinapril in six brain nuclei including subfornical organ and organum vasculosum laminae terminalis (areas lacking blood-brain barrier), and by losartan in 16 brain nuclei outside and within the blood-brain barrier in sham operated rats. However, both quinapril and losartan prevented a further reduction of central ANP as a result of myocardial infarction. These data suggest that there are effects on central ANP that result from chronic left ventricular dysfunction as well as an ACE-inhibitor and AT1-antagonist. Mechanisms and consequences of central ANP depression remain unclear. They could, however, support systemic vasoconstriction and sodium and fluid retention.

Mechanism of action of the calcium-sensing receptor in human antral gastrin cells

BACKGROUND AND AIMS

Human G cells express the calcium-sensing receptor and respond to extracellular calcium by releasing gastrin. However, the receptor on G cells is insensitive to serum calcium levels. We investigated whether this is a result of differential regulation of signaling pathways compared with parathyroid or calcitonin cells.

METHODS

Gastrin release from primary cultures of human antral epithelial cells enriched for G cells (35%) was measured by radioimmunoassay. G cells were stimulated by increasing extracellular calcium concentration for 1 hour in the presence or absence of antagonists of specific intracellular signaling pathways. Intracellular calcium levels were monitored to evaluate the effect of the antagonists on calcium influx.

RESULTS

Inhibition of phospholipase C decreased calcium-stimulated gastrin release, but blockers of adenylate cyclase, phospholipase A(2), or mitogen-activated protein kinase had no effect. Inhibition of protein kinase C, nonselective cation channels, and phosphodiesterase increased basal and calcium-stimulated gastrin release while decreasing calcium influx. These data were consistent with basally active phosphodiesterase.

CONCLUSIONS

The calcium-sensing receptor on the G cell activates phospholipase C and opens nonselective cation channels, resulting in an influx of extracellular calcium. Protein kinase C isozymes expressed by the G cells play multiple roles regulating both gastrin secretion and phosphodiesterase activity.

Fetal DNA in maternal circulation of first-trimester spontaneous abortions

OBJECTIVE

To establish whether fetal DNA can be identified in the maternal circulation in first-trimester spontaneous abortions.

METHODS

Women with confirmed spontaneous abortions and no histories of previous pregnancy were recruited. Peripheral venous blood samples were obtained and DNA extracted. Real-time quantitative polymerase chain reaction was done using SRY and beta-actin systems for calculating fetal and total DNA, respectively.

RESULTS

Of 25 women, SRY-specific signals were detected in 11 indicating that the abortions were male. The remaining 14 were negative for the SRY gene. Women with positive results were of similar gestational age to those who were negative (mean 68.4 and 69.0 days). Fetal:total DNA ratio was calculated for positive samples and ranged from 15.8 to 360.1 x 10(+3). Mean ratio was 99.4 x 10(+3) and median was 67.5 x 10(+3).

CONCLUSION

Fetal DNA is present in the maternal circulation of first-trimester spontaneous abortions.

Identification and analysis of Lydia, a LTR retrotransposon from Lymantria dispar

Degenerative PCR primers to conserved amino acid motifs were used to identify an LTR retrotransposon from Lymantria dispar. The isolated retrotransposon, Lydia, is 6655 base pairs (bp) in length and contains perfect 300 bp terminal repeats. The identified gag and pol related ORFs have a high degree of similarity to the corresponding regions of the retrotransposon Ted from Trichoplusia ni, although several reading frameshifts and missense mutations are evident. The high degree of similarity between Lydia and Ted LTRs lends support for a family of lepidopteran retrotransposons. Southern blot analysis of individuals from two geographically distinct gypsy moth populations demonstrates that Lydia is found in both populations and the position of this element within the genome of these isolated populations is variable.

Doppler tissue imaging in congestive heart failure patients due to diastolic or systolic dysfunction: a comparison with Doppler echocardiography and the atrio-ventricular plane displacement technique

BACKGROUND

Doppler tissue imaging (DTI) is an echocardiographic technique by which regional contractility, relaxation properties and time intervals are obtained easily. DTI has been reported to be relatively pre-load independent and could, in comparison with the commonly used mitral pulse wave Doppler (MPWD) method, be of clinical interest for identification of patients with diastolic dysfunction. The atrio-ventricular plane displacement (AVPD) method is an established technique to assess left ventricular systolic function.

AIMS

To determine the pulsed Doppler DTI-pattern in patients with heart failure and to examine whether it has a similar capacity as MPWD and AVPD to diagnose diastolic dysfunction.

METHODS

We studied 15 controls without congestive heart failure (CHF), 15 patients with diastolic (EF>45%+CHF) and 15 patients with systolic (EF<35%+CHF) left ventricular dysfunction and CHF.

RESULTS

The DTI maximal velocities during systole (s), early filling wave (e) and atrial filling wave (a), decrease with reduced left ventricular ejection fraction, r=0.75, r=0.56 and r=0.66 (P<0.001) and regional isovolumetric contraction and intraventricular relaxation time measured by DTI are prolonged, r=0.59 and r=0.73, respectively (P<0.001). The 15 patients with diastolic heart failure were identified by MPWD or DTI but only 11 by AVPD with 8, 10 and 9 false-positive, respectively (P<0.01, P<0.05 and NS).

CONCLUSIONS

Regional DTI show a consistent pattern in patients with left ventricular dysfunction and heart failure. Regional DTI has similar accuracy as MPWD in identifying diastolic heart failure patients and is superior to the AVPD technique. DTI may be a useful diagnostic tool in diastolic heart failure patients.

Influence of age and cardiovascular factors on regional pulsed wave Doppler myocardial imaging indices

AIMS

To describe the influence of age and other cardiovascular factors on regional pulsed wave Doppler myocardial imaging (DMI), and to compare DMI with conventional transmitral echocardiography and the atrioventricular plane displacement (AVPD) method.

METHODS AND RESULTS

Eighty-eight healthy subjects aged 20-81 years were examined by DMI, performed in the intraventricular septum just below the mitral annulus and in the corresponding lateral region, by transmitral pulsed wave Doppler echocardiography, and by AVPD. The DMI peak velocity during the left ventricular (LV) early filling phase (e), decreased with age from 12.3 +/- 2.3 cm/s in the youngest to 7.0 +/- 1.7 cm/s in the oldest tercentile (r=- 0.76, P<0.001). The DMI peak velocity during atrial contraction (a), increased from 7.5 +/- 2.2 cm/s in the youngest to 9.7 +/- 1.7 cm/s in the oldest tercentile (r=0.41, P<0.001). The DMI systolic peak velocity (s), decreased with age from 8.2 +/- 1.1 (youngest tercentile) to 6.9 +/- 1.1 (oldest tercentile), r=-0.39, P<0.001 cm/s, while the fraction shortening of the LV increased from 33.7 +/- 4.1 to 38.2 +/- 5.9% (r=0.36, P<0.01). The DMI e/a correlated with the transmitral early/atrial (E/A) (r=0.83, P<0.001) and with the AVPD measurement of diastolic function AV-LA/AV-mean (r=0.82, P<0.001). The DMI e velocity correlated with the transmitral E velocity (r=0.38, P<0.001). In the multiple regression analysis of DMI e, age was the strongest factor and LV mass index correlated inversely and independently with e. No DMI variables were influenced by gender, while transmitral E correlated with gender. The LV dimension variables explained 35% (R2 adjusted) of the DMI e velocity changes; only 7% of the transmitral E changes were explained by those variables.

CONCLUSION

Regional DMI indices are highly age-dependent. In comparision with conventional echocardiography, regional DMI might be more influenced by LV geometry and by myocardial structural changes. These findings suggest a complementary role for regional DMI to conventional echocardiography for the assessment of myocardial function.

Cellular localisation of HHV-8 in Castleman's disease: is there a link with lymph node vascularity?

AIMS

Human herpesvirus 8 (HHV-8) has been identified in multicentric Castleman's disease and in angioimmunoblastic lymphadenopathies. However, the presence of the virus does not necessarily indicate an aetiological role in these conditions. This study investigates the cell types infected by HHV-8 in Castleman's disease and examines the correlation between HHV-8 and Castleman's disease lymph node angiogenesis.

METHODS

Sixteen formalin fixed, paraffin wax embedded samples from patients with Castleman's disease (six multicentric, 10 solitary) were examined for the presence of HHV-8 using the polymerase chain reaction (PCR), non-isotopic in situ hybridisation, PCR in situ hybridisation (PCR-ISH), and real time quantitative TaqMan PCR to HHV-8 open reading frame 26 (ORF-26), and viral (v)-cyclin encoding regions. Vascularity was assessed using CD34, CD31, and factor VIII immunocytochemistry, and lymph nodes were scored as "low" or "high".

RESULTS

Five multicentric Castleman's disease and two solitary Castleman's disease biopsies were positive for HHV-8. HHV-8 was identified in approximately 10% of intranodal B lymphocytes, in endothelial cells, and in subcapsular spindle cell proliferations. The copy number of HHV-8 was low at 10-50 copies/1000 cells. The highest copy number was in subcapsular spindle cells. There was no correlation between vascularity score and HHV-8 status.

CONCLUSION

The preferential localisation of HHV-8 in subcapsular spindle cell proliferations (where early intranodal Kaposi's sarcoma initiates) and endothelial cells in Castleman's disease might finally explain the link between intranodal Kaposi's sarcoma and Castleman's disease.

Localisation of HHV-8 in AIDS related lymphadenopathy

BACKGROUND

Many lymph node abnormalities have been described in AIDS. These include opportunistic infections that sometimes result in spindle cell pseudotumours, Kaposi's sarcoma (KS), malignant lymphoma (Hodgkin's and non-Hodgkin's), and florid reactive hyperplasia. Among these, reactive hyperplasia is the most common manifestation of AIDS related lymphadenopathy.

AIM

To examine whether human herpesvirus 8 (HHV-8), the aetiological agent of KS, can be localised in AIDS related lymphadenopathy and whether its appearance in such nodes is predictive of Kaposi's sarcoma development.

METHODS

A series of human immunodeficiency virus (HIV) positive men (n = 21) with AIDS related lymphadenopathy who at the time of presentation had KS or subsequently developed KS (n = 5) were examined. The prevalence of HHV-8 was assessed in these patients using solution phase polymerase chain reaction (PCR), real time TaqMan quantitative PCR, and in cell amplification techniques (PCR in situ hybridisation (PCR-ISH) and labelled primer driven in cell amplification).

RESULTS

Using standard solution phase PCR in a nested format, only two of the 21 patients with AIDS related lymphadenopathy were positive for HHV-8. The lymph node of one of these patients contained KS lesions. Three HHV-8 positive patients were identified using TaqMan PCR (the original two positive patients and one additional patient). All of the positive patients either subsequently developed KS (n = 2) or had KS at the time of diagnosis (n = 1). Two additional patients subsequently developed KS, but were negative for HHV-8 by solution phase PCR and TaqMan PCR. Using PCR-ISH, HHV-8 amplicons were identified in some lymphoid cells (in one patient) and in spindle cells of the KS lesion in another. The positive lymphoid cells were predominantly concentrated in B cell areas of the affected lymph nodes, confirming the B cell tropism exhibited by HHV-8.

CONCLUSIONS

The presence of HHV-8 in AIDS related lymphadenopathy is predictive of KS development and probably represents seeding of HHV-8 infected B cells from the peripheral blood. These findings support a role for HHV-8 in the pathobiology of KS.

Improved in situ detection method for telomeric tandem repeats in metaphase spreads and interphase nuclei

Peptide nucleic acid technology (PNA) has become an extremely useful tool and promises to impact on molecular biology and diagnostics. These synthetic DNA analogues pair with DNA and RNA molecules according to Watson and Crick base pairing rules. This paper describes a sensitive and quick fluorescent in situ hybridisation (ISH) technique to determine DNA telomere repeat sequences (TTA GGG)n using epifluorescence microscopy. Telomeres are special, repeated structures at the end of each eukaryotic chromosome and serve as protective caps to prevent DNA rearrangements and fusion of chromosomes. A model system has been developed, using stimulated peripheral blood lymphocytes, which facilitates simultaneous detection of telomeres in metaphase as well as in interphase nuclei. A fluorescein isothiocyanate labelled PNA probe (18 mer) directed against complementary telomeric sequences at the end of each chromosome is used. In addition, a simple, easy to perform PNA-ISH protocol is described that overcomes common hybridisation problems encountered using DNA and RNA oligoprobes. Furthermore, the usefulness of a chromogenic immunocytochemical detection system is shown for PNA-ISH.

The role of protein kinase C isozymes in bombesin-stimulated gastrin release from human antral gastrin cells

Two of the most effective stimuli of gastrin release from human antral G cells are bombesin and phorbol esters. Both agonists result in activation of the protein kinase C family of isozymes, however, the exact contribution of protein kinase C to the resultant release of gastrin has been difficult to assess, possibly due to the presence of multiple protein kinase C isozymes in the G cells. The results of the present study demonstrated that the human antral G cells expressed 6 protein kinase C isozymes alpha, gamma, theta, epsilon, zeta, and mu. Of these protein kinase C, gamma and theta were translocated by stimulation of the cells by either 10 nM bombesin or 1 nM phorbol ester. Inhibition of protein kinase Cmu (localized to the Golgi complex) did not decrease bombesin-stimulated gastrin release indicating that this isozyme was not involved in the secretory process. The use of selective antagonists of the calcium-sensitive conventional protein kinase C subgroup resulted in an increase in bombesin-stimulated gastrin release and indicated that protein kinase Cgamma was involved in the desensitization of the bombesin response.

Association between HLA-DR1 and -DR3 antigens and unexplained repeated miscarriage

Few, mostly small, studies have investigated the distribution of HLA class II antigens among women with unexplained recurrent miscarriage. Although some studies have reported statistically significant associations between this syndrome and certain HLA-DR antigens--especially the -DR1 and -DR3 antigens--other studies have been unable to demonstrate such associations. For the present meta-analysis, 18 cross-sectional or case-control studies (published or unpublished) reporting on frequencies of HLA-DR1 and -DR3 antigens among Caucasian women with unexplained repeated miscarriage were identified by searching literature databases (MEDLINE and EMBASE), reading the references of identified studies, and by contacting researchers within the field. The studies comprised a total of 1508 patients. The methodological quality of most of the studies was low, especially because of small numbers of patients and because patients with only two miscarriages were included in many studies; this is defined as repeated miscarriage. The odds ratios of repeated miscarriage for the HLA-DR1 and -DR3 antigens were calculated for the individual studies and subsequently the pooled odds ratios for the studies were calculated. The combined odds ratio for HLA-DR1 was 1.29 [95% confidence interval (CI) = 1.05-1.58] (17 studies) which is statistically significant (P <0.05). The combined odds ratio for HLA-DR3 was 1.00 (95% CI 0.80-1.24) (18 studies), which is not significant. The results of the meta-analysis suggest that the HLA-DR antigen DR1 is associated with an increased susceptibility to unexplained repeated miscarriage.

Primary structure of ovine fibroblast growth factor-1 deduced by protein and cDNA analysis

The amino acid sequence of full-length ovine fibroblast growth factor-1 (FGF-1) was determined by a combination of protein and cDNA sequencing. FGF-1 cDNA analysis indicated that ovine kidney cells express mRNAs encoding both full-length FGF-1 and a truncated FGF-1 variant. An overall comparison of the ovine FGF-1 primary sequence to the eight species studied to date revealed a high degree of conservation, with ovine FGF-1 sharing 90 and 95% sequence identity with human FGF-1 and bovine FGF-1, respectively. Additionally, the FGF-1 proteins from the various species have conserved cysteine residues at positions 30 and 97 and contain acetylated amino-terminal alanine residues. Mass spectrometry analysis confirmed that the blocking group of ovine FGF-1 is also consistent with that of an acetyl-moiety. In contrast to the other FGF-1 proteins, the 154 residue primary sequence of ovine FGF-1 contains three unique amino acid differences: Arg9, Arg44, and Ile123. Ovine FGF-1, unlike human FGF-1, is a potent mitogenic factor for NIH 3T3 fibroblasts in the absence of heparin. In the presence of exogenous heparin, the mitogenic activity of ovine FGF-1 is potentiated slightly.

Expression of Schistocerca gregaria ion transport peptide (ITP) and its homologue (ITP-L) in a baculovirus/insect cell system

We expressed an N-terminally extended Schistocerca gregaria ion transport peptide (ScgITP) and its homologue (ion transport peptide-like; ITP-L) in insect Sf9 cells using baculovirus expression vectors. Antibodies raised against peptide fragments of ITP and ITP-L were used to detect and characterize the baculovirus expressed peptides (bacITP, bacITP-L). Biological activity of the expressed peptides was assayed using the highly specific bioassay for native ITP, namely the increase in ileal short-circuit current which is a measure of active Cl- transport. BacITP and bacITP-L expression was optimal in Sf9 cells infected at a multiplicity of infection of 1, grown in Grace's medium, and harvested 2-3 days after infection. Western blots showed that bacITP was 2 kDa larger than native or synthetic ITP. This difference was not due to glycosylation and could in part be attributed to post-translational cleavage of the ITP propeptide at a site 11 amino acids upstream of the cleavage site used by S. gregaria to produce native ITP. BacITP stimulated ileal short-circuit current but is significantly less active (270-fold) than synthetic ITP (synITP) possibly as a result of the N-terminal extension. Production of bacITP-L permitted us to show that it is not stimulatory in the bioassay but reduces the synITP response in vitro and thus may have some potential for enhancing the effectiveness of biological control agents such as baculoviruses.

Locust ion transport peptide (ITP): primary structure, cDNA and expression in a baculovirus system

Ion transport peptide (ITP) purified from locust nervous corpus cardiacum (CC) has previously been shown to stimulate salt and water reabsorption and inhibit acid secretion in the ileum of Schistocerca gregaria. We used the partial amino acid sequence of purified ITP to derive degenerate primers. These were used to amplify a cDNA from brain RNA using reverse transcription and the polymerase chain reaction (RtPCR). This sequence was extended using anchored PCR to yield a partial, 517bp cDNA clone. This cDNA encodes a putative ITP prohormone which could be cleaved at two dibasic amino acid sites to yield a 72 residue active amidated peptide. The deduced amino acid sequence from the cDNA agrees completely with the amino acid sequence and molecular mass (8564Da) derived from analysis of purified ITP. Relative to a family of crustacean hyperglycaemic hormones (CHH), all six cysteine residues and many other amino acid residues are conserved in ITP, establishing that ITP is a homologue. However, CHH, crab eyestalk and CC extracts from distantly related insects have no action, whereas CC extracts from closely related insects are active on the locust ITP assay, showing that the bioassay is selective. Insect Sf9 cells transfected with a baculovirus containing our partial cDNA secreted a potent stimulant of locust ileal transport, confirming that the peptide encoded by our ITP clone has biological activity. The mRNA for ITP is restricted to the brain and CC. Interestingly, a related mRNA is observed in other tissues which are not active on the ITP bioassay.

Identification of a 5' truncated non-LTR-retrotransposon, YAKPs1, from the variegated cutworm, Peridroma saucia, using PCR

Retrotransposable elements encode for several polypeptides that contain a number of conserved amino acid motifs, especially in the region encoding reverse transcriptase. We have used these motifs to design primers for the PCR amplification of retrotransposon DNA. These primers have allowed us to isolate a retroposon, or LINE (long interspersed nuclear element), from the pest insect, Peridroma saucia. DNA sequence analysis of this element, YAKPs1, demonstrated a high degree of homology to a number of retroposons from Drosophila melanogaster, in particular the Fw and Doc elements with homologies of up to 69%. Determination of the complete sequence of the YAKPs1 element will enable a detailed analysis of its evolutionary relatedness to other elements as well as a greater insight into its mode of action.