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The development of an effective vaccine against human immunodeficiency virus is considered to be the most practicable means of controlling the advancing global AIDS epidemic. Studies with the domestic cat have demonstrated that vaccinal immunity to infection can be induced against feline immunodeficiency virus (FIV); however, protection is largely restricted to laboratory strains of FIV and does not extend to primary strains of the virus. We compared the pathogenicity of two prototypic vaccine challenge strains of FIV derived from molecular clones; the laboratory strain PET F14 and the primary strain GL8 414 . PET F14 established a low viral load and had no effect on CD4 + - or CD8 + -lymphocyte subsets. In contrast, GL8 414 established a high viral load and induced a significant reduction in the ratio of CD4 + to CD8 + lymphocytes by 15 weeks postinfection, suggesting that PET F14 may be a low-virulence-challenge virus. However, during long-term monitoring of the PET F14 -infected cats, we observed the emergence of variant viruses in two of three cats. Concomitant with the appearance of the variant viruses, designated 627 W135 and 628 W135, we observed an expansion of CD8 + -lymphocyte subpopulations expressing reduced CD8 β-chain, a phenotype consistent with activation. The variant viruses both carried mutations that reduced the net charge of the V3 loop (K409Q and K409E), giving rise to a reduced ability of the Env proteins to both induce fusion and to establish productive infection in CXCR4-expressing cells. Further, following subsequent challenge of naïve cats with the mutant viruses, the viruses established higher viral loads and induced more marked alterations in CD8 + -lymphocyte subpopulations than did the parent F14 strain of virus, suggesting that the E409K mutation in the PET F14 strain contributes to the attenuation of the virus.

The distributions of occludin and claudin-1, two tight junction-associated integral membrane proteins were investigated by immunohistochemical analysis of whole-mount preparations of the blood vessels in the myelinated streak of the rabbit retina. Light microscopy revealed that occludin and claudin-1 immunoreactivities were abundant along the interface of adjacent endothelial cells of all blood vessels. Electron microscopy revealed that both proteins were distributed in a regular pattern (at regular intervals of approximately 80 nm) along the length of tight junctions, probably in the regions of tight junction strands. No other structures or cell types expressed either of these two proteins in the myelinated streak. Whereas occludin immunoreactivity was concentrated only at the tight junction interface, claudin-1 immunoreactivity also extended into the cytoplasm of the endothelial cells, suggesting a different structural role for claudin-1 than for occludin at tight junctions. Retinal pigment epithelial cells expressed occludin around their entire circumference, consistent with the function of these cells as a barrier separating the retina from the leaky vessels of the choroid. Also consistent with the association of occludin expression with vessels that exhibit functional tight junctions, this protein was expressed at only a low level in, and showed an irregular distribution along, the vessels of the choroid, a vascular bed that lacks blood-barrier properties. Further, the distribution of occludin was examined during formation and remodelling of the rat retinal vasculature. Occludin expression was evident at the leading edge of vessel formation and was found on all vessels in both the inner and outer vascular plexus. Numerous vascular segments at the early stage of vascular formation and regression lost occludin expression. The biological significance of this transient loss of occludin expression in terms of barrier function remains to be elucidated.

Mechanisms of placentation are very diverse in mammals and range from types in which the uterine epithelium is breached by the implanting blastocyst to those where the epithelium remains intact. Despite these differences in mechanisms, the initial response of the plasma membrane of uterine epithelial cells is remarkably similar across mammalian species which has led to the term ‘plasma membrane transformation’ to encapsulate the concept of a common beginning to implantation. Membrane phenomena similar to those of mammals have now been observed in some viviparous lizards at the ultrastructural level during early pregnancy, and we propose extending the concept of ‘plasma membrane transformation’ to lizards with live birth.

Aims: The aims of this study were to study the efficacy and tolerability of felodipine extended release (ER) 5 mg and metoprolol controlled release (CR/ZOC) 50 mg given as a fixed combination (Logimax) or as a free combination in elderly (age greater than 60 years) hypertensive patients, using ambulatory blood pressure (BP) monitoring. A secondary aim was to relate the efficacy of the free and fixed combinations with pharmacokinetic profiles. Methods: This was a double-blind, placebo-controlled randomised three-way crossover multi-centre study. BP was measured for 26 h using ambulatory blood pressure monitoring (ABPM), which was performed on the last day of the three treatment phases. Results: Mean sitting BPs, measured during the trough period with ABPM, were significantly lower with both the free and fixed combinations of metoprolol and felodipine than placebo (141/83 mmHg free, 140/83 mmHg fixed, 156/93 mmHg placebo). The mean BPs measured over 24 h using ABPM were 143/82 mmHg, 140/82 mmHg and 158/93 mmHg for the free, fixed and placebo treatment arms, respectively. The trough-to-peak ratios (T:P) were 75% and 79% for the systolic BP and 70% and 70% for the diastolic BP for the free and fixed combinations, respectively. Pharmacokinetic evaluation revealed identical plasma concentration–time curves for felodipine given as the free or fixed combination. Comparison of the plasma concentration–time curves for metoprolol revealed a delay in the release rate from the fixed combination formulation. No significant differences in BP control between the active treatments were noted during this period. Of 26 patients entered into the study, 3 withdrew during active phase for non-drug-related reasons. No patient withdrew from active treatment due to treatment-related adverse events. The frequency of adverse event reporting for the fixed combination of felodipine and metoprolol was similar to that for placebo (60% and 58%, respectively). Conclusion: The results suggest that once-daily dosing with either the free or fixed combination of felodipine 5 mg and metoprolol 50 mg produces a significant sustained reduction in systolic and diastolic BP with similar plasma concentration profiles over a 24-h period.

We used a single administration of clomiphene citrate (CC), a synthetic oestrogen that is prescribed for infertility treatment, in combination with either a single administration of oestradiol 17beta (E2) or progesterone (P4) to assess the combined effects of these hormones on the uterine surface. The aim of these experiments was to investigate how CC in combination with these hormones affected both expression of oligosaccharides on the uterine surface and membrane architecture further elucidating CC's agonistic/antagonistic properties. Ovariectomized sexually mature rats were given combinations of E2 and CC (E2 + CC) or P4 and CC (P4 + CC) or P4 and E2 (P4 + E2) and were killed 24 h later. Uterine tissue was labelled with the lectin Phytolacca americana conjugated with avidin and subsequently labelled with biotinylated ferritin and prepared for transmission electron microscopy. Results of the administration of these hormone combinations indicate that CC, when administered in conjunction with E2, had the ability to downregulate expression of oligosaccharides on the membrane surface caused by E2. When administered with P4, CC had the ability to upregulate the effects of P4. Thus, when combined with E2, CC has an antagonistic effect but when combined with P4, CC has an agonistic effect.

Summary We have studied histochemically the effects of clomiphene citrate on the expression of oligosacchrides on the apical plasma membrane of uterine epithelial cells using the lectin Phytolacca americana . Ovariectomized sexually mature rats were given a single injection of either clomiphene in two concentrations or estradiol 17p or progesterone and were killed 24 hr later. Uterine tissue was labeled with Phytolacca americana conjugated with avidin and subsequently labeled with biotinalyted ferritin and prepared for transmission electron microscopy. Our results indicate that clomiphene and to a lesser degree progesterone significantly increased lectin binding. However, the increase was not as large as that observed with a single dose of estrodiol 17p. When the proportion of lectin positivity in relation to total membrane length was analyzed, treatment with clomiphene and progesterone did not have significantly different effects. Low dose clomiphene did not have a significant effect as compared with controls. Our data show that clomiphene has a dose-dependent adverse effect on lectin binding as compared with ovarian hormones. We suggest that these effects contribute to low pregnancy rates with clomiphene use.

Infection with feline immunodeficiency virus (FIV) leads to the development of a disease state similar to AIDS in man. Recent studies have identified the chemokine receptor CXCR4 as the major receptor for cell culture-adapted strains of FIV, suggesting that FIV and human immunodeficiency virus (HIV) share a common mechanism of infection involving an interaction between the virus and a member of the seven transmembrane domain superfamily of molecules. This article reviews the evidence for the involvement of chemokine receptors in FIV infection and contrasts these findings with similar studies on the primate lentiviruses HIV and SIV (simian immunodeficiency virus).

CCR5 and CXCR4 are the principal CD4-associated coreceptors used by human immunodeficiency virus type 1 (HIV-1). CXCR4 is also a receptor for the feline immunodeficiency virus (FIV). The rat CXCR4 cannot mediate infection by HIV-1 NDK or by FIV PET (both cell line-adapted strains) because of sequence differences with human CXCR4 in the second extracellular loop (ECL2). Here we made similar observations for HIV-1 89.6 (a strain also using CCR5) and for a primary HIV-1 isolate. It showed the role of ECL2 in the coreceptor activity of CXCR4 for different types of HIV-1 strains. By exchanging ECL2 residues between human and rat CXCR4, we found that several amino acid differences contributed to the inactivity of the rat CXCR4 toward HIV-1 89.6 . In contrast, its inactivity toward HIV-1 NDK seemed principally due to a serine at position 193 instead of to an aspartic acid (Asp193) in human CXCR4. Likewise, a mutation of Asp187 prevented usage of CXCR4 by FIV PET . Different mutations of Asp193, including its replacement by a glutamic acid, markedly reduced or suppressed the activity of CXCR4 for HIV-1 NDK infection, indicating that the negative charge was not the only requirement. Mutations of Asp193 and of arginine residues (Arg183 and Arg188) of CXCR4 reduced the efficiency of HIV-1 infection for all HIV-1 strains tested. Other ECL2 mutations tested had strain-specific effects or no apparent effect on HIV-1 infection. The ECL2 mutants allowed us to identify residues contributing to the epitope of the 12G5 monoclonal antibody. Overall, residues with different charges and interspersed in ECL2 seem to participate in the coreceptor activity of CXCR4. This suggests that a conformational rather than linear epitope of ECL2 contributes to the HIV-1 binding site. However, certain HIV-1 and FIV strains seem to require the presence of a particular ECL2 residue.

This chapter discusses the analysis of the protective immunity induced by feline immunodeficiency virus (FIV) vaccination. Since its discovery in 1986, FIV infection has been shown to result in an immunodeficiency in cats that is similar to AIDS in human beings. The virus is now recognized as a long-established and important feline pathogen and an appropriate animal model for human immunodeficiency virus (HIV) infection, playing a key role in the development of vaccines against HIV. Furthermore, because FIV induces significant disease in cats, the development of an effective FIV vaccine is of great veterinary interest. Protection against FIV infection has been achieved by immunizing cats with a whole inactivated virus (WIV) vaccine produced from the FL4 feline lymphoblastoid cell line, which is persistently infected with the Petaluma isolate of FIV (FIV/PET). This cell line appears to be unique, because it produces large amounts of FIV/PET rich in envelope glycoprotein (Env) that is well preserved during purification.

Scanning electron microscopy has been used in a preliminary study to evaluate the value of steroid replacement therapies in restoring uterine epithelium in postmenopausal patients. All therapies resulted in increased epithelium over controls, but one regime was markedly better than others.

To test the potential of a multigene DNA vaccine against lentivirus infection, we generated a defective mutant provirus of feline immunodeficiency virus (FIV) with an in-frame deletion in pol (FIVΔRT). In a first experiment, FIVΔRT DNA was administered intramuscularly to 10 animals, half of which also received feline gamma interferon (IFN-γ) DNA. The DNA was administered in four 100-μg doses at 0, 10, and 23 weeks. Immunization with FIVΔRT elicited cytotoxic T-cell (CTL) responses to FIV Gag and Env in the absence of a serological response. After challenge with homologous virus at week 26, all 10 of the control animals became seropositive and viremic but 4 of the 10 vaccinates remained seronegative and virus free. Furthermore, quantitative virus isolation and quantitative PCR analysis of viral DNA in peripheral blood mononuclear cells revealed significantly lower virus loads in the FIVΔRT vaccinates than in the controls. Immunization with FIVΔRT in conjunction with IFN-γ gave the highest proportion of protected cats, with only two of five vaccinates showing evidence of infection following challenge. In a second experiment involving two groups (FIVΔRT plus IFN-γ and IFN-γ alone), the immunization schedule was reduced to 0, 4, and 8 weeks. Once again, CTL responses were seen prior to challenge in the absence of detectable antibodies. Two of five cats receiving the proviral DNA vaccine were protected against infection, with an overall reduction in virus load compared to the five infected controls. These findings demonstrate that DNA vaccination can elicit protection against lentivirus infection in the absence of a serological response and suggest the need to reconsider efficacy criteria for lentivirus vaccines.

To investigate quality of life in patients with gastro-oesophageal reflux disease.A series of 704 patients were randomised to treatment with ranitidine 150 mg bd, omeprazole 10 mg om or omeprazole 20 mg om for 2 weeks. Asymptomatic/mildly symptomatic patients were followed for 12 months.The Psychological General Well-Being index and the Gastrointestinal Symptom Rating Scale were completed before and during short-term and intermittent treatment.The quality of life response rate was80%. The majority of the patients receiving omeprazole 20 mg om (55%) had symptom relief after 2 weeks despite the fact that more patients on ranitidine required 4 weeks' treatment and an increased dose. There was no difference in the reflux dimension of Gastrointestinal Symptom Rating Scale between treatments in the initial treatment phase, but the total Gastrointestinal Symptom Rating Scale score improved significantly more on omeprazole 10 mg om than on ranitidine 150 mg bd (p = 0.006). Both doses of omeprazole improved the total Psychological General Well-Being score more than ranitidine (omeprazole 10 mg om versus ranitidine 150 mg bd, p = 0.005, omeprazole 20 mg om versus ranitidine 150 mg bd, p = 0.031). During follow-up, relapsing patients returned to pre-treatment symptom and well-being scores, but these dimensions were restored after treatment.The quality of life is impaired in patients presenting with reflux symptoms. Irrespective of whether the patients presented with endoscopy positive or endoscopy negative reflux disease, treatment on demand improved the quality of life.

A monoclonal antibody which blocks infection with feline immunodeficiency virus (FIV) was found previously to react with the cell surface molecule CD9, implicating CD9 in the process of virus entry. We report here that inhibition by anti-CD9 antibody does not operate at the level of virus entry but at a subsequent stage in the virus life-cycle. Moreover, inhibition of infection is independent of the passage history of the virus or the virus subtype. Inhibition of FIV infection by anti-CD9 antibody does not operate in 3201 cells, which do not express this surface antigen. However, ectopic expression of CD9 on 3201 cells enhances infection with FIV, suggesting that the role of CD9 may be direct rather than via cellular signalling pathways. These results suggest a novel control point in the lentivirus life-cycle which might be susceptible to modulation by natural antagonists.

A pooled data analysis of two double-blind studies encompassing 1137 episodes of community-acquired pneumonia in hospitalised adults, of which 560 were treated with sparfloxacin and 577 were randomised to comparator antibacterial agents (amoxycillin/clavulanic acid, erythromycin or amoxycillin administered at reference dosages), was performed. The global efficacy rate at the end of treatment in evaluable patients treated with sparfloxacin was 88.3% compared with 84.1% in those who received comparator antibacterial agents. This analysis verified the efficacy of this new aminofluoroquinolone, given orally once daily, in the treatment of community acquired pneumonia. The overall outcome favoured sparfloxacin for use in the empirical treatment of community-acquired pneumonia.

A multicentre, double-blind, randomized study was conducted in patients with osteoarthritis (OA) of the hip or knee in order to compare the efficacy and safety of the new cyclooxygenase-2 (COX-2) inhibitor, meloxicam, with diclofenac sodium, a conventional treatment for this condition. Three hundred and thirty-six patients were treated with oral meloxicam 7.5 mg once daily or diclofenac 100 mg slow release once daily for 6 months. There were no significant differences between the treatment groups with respect to overall pain, pain on movement, global efficacy or quality of life scores at the end of treatment, all of which showed good levels of improvement. Sixty-six patients were withdrawn after the start of the double-blind phase due to adverse events (n = 21, meloxicam; n = 31, diclofenac) or to lack of efficacy (seven in each group). The median of dose paracetamol taken concomitantly was statistically significantly lower in the meloxicam group than in the diclofenac group (185 vs 245 mg/day; P = 0.0123) with a comparable proportion of patients taking concomitant paracetamol therapy in both groups. Both drugs were well tolerated, although severe adverse events, treatment withdrawal and clinically significant laboratory abnormalities were more common with diclofenac than with meloxicam. Thus, meloxicam 7.5 mg is a safe and effective treatment for OA of the hip and knee which demonstrates a trend towards an improved safety profile compared with diclofenac.

Whole inactivated virus (WIV) vaccines derived from the FL4 cell line protect cats against challenge with feline immunodeficiency virus (FIV). To discover whether the protective effects of WIV could be reproduced by the isolated Env component, either WIV or immunoaffinity-purified FIV gp120 from the FL4 cell line was administered to cats. Although both vaccines induced high levels of virus neutralizing antibodies, purified Env was much less effective than WIV in protecting cats against viraemia. However, reduced virus load in PBMCs was evident in all Env-immunized cats compared to controls. Analyses of antibody responses to bacterial expression products of FIV Env, which were high in Env-immunized cats but low in animals receiving the WIV vaccine, suggested that the partially denatured, monomeric Env induces a less effective antiviral immune response than WIV. Hence, the superior immunogenicity of WIV may be due to the presentation of the native oligomeric structure of Env on virions.

The human uterine glandular epithelium undergoes a sequence of well characterized changes during the menstrual cycle that presumably play an important role in preparation for blastocyst implantation. The aim of this study was to measure objectively glandular volume over the entire menstrual cycle and compare the results with eight different clinical superovulation or hormone replacement therapy (HRT) subject groups. Endometrial biopsies were taken from control normal menstrual cycle subjects (n = 96), and eight other smaller groups of women who had received different in-vitro fertilization (IVF) related treatments. The total area of glandular epithelium was objectively measured from routine histological slides using computerized image analysis. Control menstrual cycle results showed a significantly greater gland area in the early secretory stage of the cycle than at any time between the early proliferative through to the mid-late proliferative stages (P < 0.05). IVF patients receiving clomiphene citrate and human menopausal gonadotrophin had a significantly smaller glandular area than those in the control groups at equivalent stages of the menstrual cycle. The use of progesterone supplementation removed this significant difference. Patients on the ?Flare' regime had the highest gland area, although this was not significantly different from controls. Buserelin down-regulation gave a gland area that was closest to the normal cycle controls. The three HRT groups showed high variability in gland volume between patients. The results from this study demonstrate that superovulation can cause significant alterations in endometrial gland volume, but that these do not necessarily preclude implantation.

The treatment of community-acquired pneumonia is empirical in most cases and must cover a wide range of potential pathogens, such as Streptococcus pneumoniae, including penicillin-resistant strains, Haemophilus influenzae and intracellular microorganisms. The objective of this double-blind, randomized, parallel group study was to compare the efficacy and safety of sparfloxacin (400 mg loading dose, followed by 200 mg o.d.) with that of oral amoxycillin-clavulanic acid (500/125 mg t.i.d.) or oral erythromycin (1 g b.i.d.), during 7-14 days in 808 patients with confirmed community-acquired pneumonia. The overall success rates for sparfloxacin (87%), amoxycillin-clavulanic acid (80%) and erythromycin (85%) were similar in evaluable patients, and the equivalence hypothesis used for the statistical analysis showed at least an equivalent efficacy for the three antibiotics tested. The analysis of microbiologically documented infections (40% of the patients) showed that overall success rates were similar for S. pneumoniae and H. influenzae infections. Treatment withdrawal was necessary in 3.5, 2.5 and 7.7% of the patients treated with sparfloxacin, amoxycillin-clavulanic acid and erythromycin, respectively. This study indicates that sparfloxacin was at least as effective as amoxycillin-clavulanic acid or erythromycin in the treatment of mild-to-moderate community-acquired pneumonia and that the adverse effects were similar in the three groups.

Definition of the immunological mechanisms involved in protective immunity against lentiviral infections is crucial to the development of an effective vaccine. The induction of gag- and env-specific cell-mediated immune responses was studied in cats following vaccination with whole inactivated feline immunodeficiency virus (FIV). Cats were immunized by inoculation with three doses of paraformaldehyde-inactivated FIV, derived from the feline lymphoid cell line, FL-4, which is persistently infected with the Petaluma isolate of FIV. Autologous or allogeneic skin fibroblasts either infected with recombinant FIV gag- or env-vaccinia virus or pulsed with FIV env peptides were used as targets in chromium-51 release assays. Effector cells were fresh peripheral blood mononuclear cells. Following the third immunization, all vaccinated cats, but none of the control cats immunized with adjuvant alone, had detectable FIV env-specific lymphocytotoxicity in their peripheral blood. Two cats also exhibited gag-specific activity. There was no recognition of either allogeneic skin fibroblasts infected with recombinant vaccinia virus or autologous target cells infected with wild-type vaccinia virus, indicating the specificity and MHC-restricted nature of the response. Vaccinated cats, but not control cats, were protected from challenge with the homologous Petaluma isolate of FIV. Partial epitope mapping of the env-specific cytotoxic response was performed using overlapping 10-amino acid peptides from the env V3 domain of FIV. This response appeared to be directed at env peptide 1 (RAISSWKQRN) and env peptide 3 (QRNRWEWRPD), which lie adjacent to a beta-turn within the V3 domain.(ABSTRACT TRUNCATED AT 250 WORDS)

Two surveys of hypertension treatment in Europe have revealed major differences between doctor perception, patient belief and the reality of BP control. The first survey (part of the Cardiomonitor Study) investigated 23,339 cardiovascular patients treated by 1471 doctors in Italy, Spain, France, the UK and Germany. The second survey researched attitudes to treatment among 301 general practitioners and 300 patients in Italy, France and the UK. Cardiomonitor revealed that hypertension was poorly controlled, with only 37% of patients achieving target BP. In contrast, the second survey revealed that doctors believed that target BP was reached in the majority (76%) of their treated patients with hypertension, while an even higher percentage of patients (95%) believed their BP to be well controlled. There were significant discrepancies in the perceived reasons for treatment failure between doctors and patients. Most doctors considered poor compliance with therapy to be the main reason for failure to achieve target BP. In contrast, most patients reported good compliance, blaming poor efficacy or side-effects for treatment failure. Objective studies suggest that compliance is lower than patients report and can be reduced by factors that affect quality of life, such as side-effects of treatment, complex dosing regimens, changes in therapy and concern about poorly controlled disease. This argues for effective, well-tolerated antihypertensive drugs that can be taken once daily, enabling quality of life to be maintained throughout treatment.

The safety and efficacy of dirithromycin and clarithromycin were compared in a single-blind, multicentre study of patients with acute bacterial exacerbation of chronic bronchitis (AECB). Patients received either dirithromycin, 500 mg once daily for 5 days, or clarithromycin, 250 mg twice daily for 7 days. A total of 212 patients entered the study, of whom 191 qualified for efficacy analysis. Favourable post-therapy clinical and bacteriological response rates for qualified patients (95 dirithromycin and 96 clarithromycin) were similar: 89.5% and 68.8% for dirithromycin vs 94.8% and 71.9% for clarithromycin. At late post-therapy evaluation, favourable clinical and bacteriological response rates were achieved in 98.8% and 96.2% of dirithromycin patients and 95.3% and 93.3% of clarithromycin patients, respectively. These differences were neither statistically nor clinically significantly different. Both drugs had similar efficacy against Haemophilus influenzae and both were well tolerated. Dirithromycin, administered as a single daily dose for just 5 days resulted in complete compliance in all but four patients. In clarithromycin-treated patients, requiring a 7-day course of twice-daily treatment, compliance was less satisfactory, with 12 patients failing to comply, though the between-group difference was not statistically significant. It can be concluded that 5 days of dirithromycin, 500 mg once daily is as safe and effective as 7 days of clarithromycin, 250 mg, twice daily in the treatment of AECB.

Whole inactivated virus vaccines from the FL4 cell line protected against challenge with homologous feline immunodeficiency virus (Petaluma strain) but not against a heterologous FIV isolate (GL-8) which is distinct from the Petaluma strain in virus neutralization. Protection was associated with a type-specific neutralizing antibody response and was retained when the challenge virus was propagated in an unrelated cell line.

Scanning electron microscopy was used to evaluate the surface ultrastructure of uterine luminal epithelial cells from ovariectomized rats treated with either, high or low doses of Clomiphene citrate or estradiol-17 beta or progesterone given on consecutive days. Light microscopy was used to evaluate the surface epithelium and morphometric methods were used to measure cell height. It was found that clomiphene treatment produced ultrastructural surface features some of which were similar to those seen with hormone treatments and others unique to clomiphene alone. Features reminiscent of oestrogen treatment include hyperplasia and hypertrophy of the luminal epithelium, an increase in the length and density of microvilli and the formation of gland "hillocks". Features reminiscent of progesterone treatment include the development of pinopods and secretion droplets. Features unique to clomiphene treatment include possible stratification of the luminal epithelium, the presence of surface lesions, irregular and doughnut shaped cells, areas of microvilli free plasma membrane and an increase in cell height when compared to the effects of oestrogen and progesterone. It is clear that the effects of clomiphene are both dose and duration dependent; and that some of the morphological features elicited with clomiphene treatment are similar to those seen with the hormone treatments. Overall clomiphene induced features are different to those elicited with either of the hormone treatments tested.

Acquired immunodeficiency syndrome (AIDS) is a lentivirus-induced disease caused by the human immunodeficiency virus (HIV) (Barre-Sinoussi et al, 1983; Gallo et al, 1984). HIV infection occurs worldwide and is a major threat to world health. There is, therefore, an urgent requirement for the development of effective vaccines to prevent the spread of the virus. However, there are many obstacles to the production of such a vaccine. Lentiviral infection is persistent despite the development of a vigorous immune response, there is no recovery from infection. Instead, disease almost inevitably occurs following a long latent period. Given these obstacles, it has been recognised that although vaccination may not protect completely against HIV infection, the onset of the clinical signs which result from infection may be prevented or at least delayed.

1. A randomised, placebo controlled, double-blind, parallel group study was conducted to assess the effect of tenidap sodium, a novel cytokine modulating drug, on the stable hypotensive response to the angiotension converting enzyme (ACE) inhibitor enalapril in subjects with mild to moderate, uncomplicated, essential hypertension. 2. Twenty-four male and female hypertensives, aged 33-77 years, received either 120 mg tenidap sodium or matched placebo daily for 22 days concomitantly with enalapril. 3. Mean endpoint supine and standing, systolic and diastolic pressures remained within 10% of baseline in each treatment group. However, the endpoint values were marginally above baseline during double-blind treatment with tenidap and marginally below baseline in the group receiving placebo. The increases in supine and standing systolic pressures in the tenidap group differed significantly from the changes in the placebo group. There were no significant differences between groups in changes in pulse rate. 4. Gastrointestinal side effects of mild to moderate severity attributed to treatment with tenidap were experienced by five subjects, one of whom was withdrawn during the third week of treatment. One subject receiving placebo was withdrawn because of a moderate headache attributed to study treatment. 5. The results of this study suggest that treatment with tenidap may interfere with the anti-hypertensive efficacy of ACE inhibitors. It is recommended that blood pressure should be monitored when tenidap is administered concomitantly with an ACE inhibitor.

A monoclonal antibody vpg15 has been identified which recognizes a putative cellular receptor for feline immunodeficiency virus (FIV). The antibody immunoprecipitates a single 24,000 MW species from feline cells. The molecular size and pattern of expression of the ligand for the vpg15 antibody displayed similarities to that of the human leucocyte differentiation antigen CD9. The reactivity of the vpg15 antibody was therefore compared with that of the anti-human CD9 antibody FMC56, an antibody which cross-reacts with feline cells. Expression of the vpg15 ligand correlated well with the reactivity of the FMC56 antibody on peripheral blood leucocytes and a panel of feline cell lines. Furthermore, the anti-human CD9 antibody reacted with murine fibroblast cells which had been transfected with high molecular weight feline DNA and immunoselected with the vpg15 antibody. FMC56 and vpg15 immunoprecipitated a similar 24,000 MW species from surface-iodinated feline cells and depletion of the vpg15 ligand from cell lysates resulted in a corresponding depletion of the FMC56 ligand. The data demonstrate that the vpg15 antibody recognizes the feline homologue of human CD9 and implicate feline CD9 as a cellular receptor for FIV.

Feline immunodeficiency virus (FIV) is a retrovirus causing significant disease in cats. The virus has been shown to be similar biologically to the human immunodeficiency virus (HIV), the cause of acquired immunodeficiency syndrome (AIDS) in humans. Much interest has been expressed in the use of FIV as an animal model for HIV vaccination studies. Both FIV and HIV belong to the lentivirus group of retroviruses. While there are several effective vaccines against feline leukaemia virus (FeLV), a mammalian type C retrovirus, at present there are no effective vaccines against lentiviruses. This review illustrates the obstacles to the production of vaccines against FIV or HIV. FIV vaccine studies conducted in several laboratories are reviewed, the results are compared and factors important for inducing protection from FIV infection are discussed.

The therapeutic efficacy of long acting diltiazem 300 mg od (Tildiem LA) was compared with sustained release nifedipine 20 mg bd and bendrofluazide 5 mg od in a multicentre study with 230 patients diagnosed with mild to moderate essential hypertension, with 77, 77 and 76 randomized to the diltiazem, nifedipine SR and bendrofluazide groups respectively. Patients were entered into this randomised, single (investigator) blind, parallel-group multicentre study if the systolic and diastolic blood pressures wereor = 145 mm Hg and/or 95 mm Hg respectively at the admission visit. Twenty-one general practitioners and two hospital physicians monitored patients at baseline and at four and eight weeks of continuous dosing. After eight weeks of therapy, clinically acceptable control of blood pressure was seen in all groups: reductions were 19.2/13.5 mm Hg, 20.4/14 mm Hg and 18.5/10.8 mm Hg for the Tildiem, nifedipine and bendrofluazide groups respectively. Significant differences were shown between bendrofluazide and the other two groups on diastolic pressures (p = 0.01). The non-significant trend was for systolic pressures to mirror these effects. Significantly higher withdrawals caused by adverse events were seen with nifedipine. These were as follows: 14 patients receiving nifedipine (18%), 5 patients receiving diltiazem (6%) and 4 patients receiving bendrofluazide (5%). The difference in this withdrawal rate between treatments was statistically significant (p = 0.01). Post hoc tests revealed that both diltiazem and bendrofluazide had statistically significant lower withdrawals for adverse events than the nifedipine group (p = 0.047). Nifedipine was associated with a marginal increase in standing apex pulse rate and only diltiazem LA significantly maintained serum potassium levels. These results indicate that diltiazem 300 mg is an effective antihypertensive agent and is equivalent in efficacy to nifedipine SR 20 mg and both are superior to bendrofluazide. Nifedipine SR was however the worst tolerated and had the highest withdrawal rate (p = 0.013).

Background Tetherin (BST-2) is an interferon-inducible transmembrane protein that inhibits the release of enveloped viruses from infected cells. Here, we characterise the feline homologue of tetherin and assess its effects on the replication of feline immunodeficiency virus (FIV). Results A feline homologue of tetherin was amplified from IL2dependent T cell cDNA. Real-time PCR analyses revealed that feline tetherin transcripts were expressed in many feline cell lines and were induced by interferons (a, ω or g). Like human tetherin, feline tetherin displayed potent inhibition of FIV and HIV-1 particle release, however, this activity resisted antagonism by either HIV-1 VPU, or the FIV Env and “OrfA” proteins. Further, as over-expression of a complete FIV genome in trans could not overcome feline tetherin, these data suggest that FIV lacks a functional tetherin antagonist. When expressed stably in feline cell lines, tetherin did not abrogate the replication of FIV, indeed, syncytia formation was significantly enhanced in tetherin-expressing cells infected with CD134-independent strains of FIV (FIV Fca-F14 and FIV Pco-CoLV). Confocal microscopy revealed co-localisation of tetherin and FIV envelope glycoprotein (Env) in regions at the periphery of syncytia. Moreover, while treatment of feline cells with interferon-ω suppressed viral protein production and release (consistent with the pleiotropic actions of type-l interferon on viral replication), syncytia formation was enhanced in cells treated with interferon-ω either preor post- infection with a CD134-independent strain of FIV. Conclusions While feline tetherin prevents the release of nascent viral particles, cell to cell spread remains efficient in the presence of abundant viral receptors and interferoninduced up-regulation of tetherin expression may enhance syncytia formation. Accordingly, tetherin expression in vivo may promote the selective expansion of viral variants capable of more efficient cell to cell spread; contributing to the emergence of CD134-independent strains of FIV.

The precision and measurement agreement of two gamma-ray computed tomography forearm bone scanners have been evaluated. The inherent precision in vitro for the Stratec SCT 900 scanner was 0.28% compared with 0.04% for the OSCAR scanner. The measurements were linear over the range of densities found in humans. Increasing thickness of the cortical shell dramatically increased trabecular bone attenuation coefficient (TBAC) for the SCT 900, but only slightly affected results with the OSCAR. Short-term precision of the SCT 900 in 22 women (1.26%) was not as good as that previously reported for the OSCAR (0.50%). The measured TBAC for the same patients was significantly greater with the SCT 900. Corrections for the error introduced by the cortical shell of the radius with the SCT were calculated. Using this correction similar TBAC values could be obtained with both scanners, but the variance of the differences was too great for the results to be used interchangeably. Published bone density data for normal subjects indicate that Scottish women lose more trabecular bone in the two decades after 50 years of age than those in the Federal Republic of Germany.

In a multicentre crossover study of 97 patients with mild hypertension, the incidence and severity of adverse effects were observed during the first 14 days of treatment with amlodipine, nifedipine retard or placebo. Amlodipine (5 mg) once daily was equipotent to nifedipine retard (20 mg) twice daily. At these doses, the incidence of adverse effects was significantly greater during treatment with nifedipine retard (41%) than with amlodipine (27%, P0.05) or placebo (16%, P0.01). In particular, headache and flushing occurred significantly less frequently during the first 14 days of treatment with amlodipine than with nifedipine retard. The lower incidence and reduced severity of vasodilatory side-effects associated with amlodipine resulted in fewer withdrawals during initiation of therapy (2 on amlodipine compared with 7 on nifedipine retard).

A double-blind, randomised, parallel-group study was performed to compare the efficacy and tolerability of a new extended-release tablet containing felodipine and metoprolol with each constituent agent as monotherapy. After a 4-week placebo period, 159 patients with mild-to-moderate essential hypertension were randomised to receive either the combination tablet of felodipine and metoprolol 10/100 mg, felodipine 10 mg or metoprolol 100 mg once daily if supine diastolic blood pressure wasor = 95 mmHg. After 12 weeks of active treatment, reductions in supine systolic/diastolic blood pressure 24 h after dosing were 20/14, 13/10 and 11/8 mmHg with felodipine-metoprolol, felodipine and metoprolol, respectively. The differences in blood pressure changes were 7/4 mmHg (p = 0.004/0.006) and 8/5 mmHg (p = 0.0002/0.0001) between the fixed combination and felodipine and metoprolol, respectively. Blood pressure response (defined as a diastolic blood pressureor = 90 mmHg and/or a reductionor = 10 mmHg) after 12 weeks of treatment was greater with the combination than with felodipine or metoprolol alone: 85% vs 72% (p = 0.06) and 54% (p = 0.001), respectively. Treatments were well tolerated and adverse events were as expected from previous studies with each agent and did not differ in frequency between groups. In conclusion, the extended-release tablet formulation of felodipine-metoprolol 10/100 mg produces a clinically relevant and significantly greater blood pressure reduction 24 h after dosing than either agent as monotherapy without decreasing tolerability.

The efficacy and tolerability of amlodipine (5 mg, once daily), nifedipine retard (20 mg, twice daily), and placebo were compared in a multicenter, three-way, crossover study involving 97 patients with mild-to-moderate hypertension. Each patient underwent three, 2-week treatment periods separated by 2-week washout periods without therapy. Comparable and significant (p0.05) blood pressure reductions were observed after amlodipine and nifedipine retard when compared with placebo, except in the case of supine systolic blood pressure with nifedipine retard. A significantly greater incidence of treatment-related side effects was observed with nifedipine retard (41%) compared with amlodipine (27%, p0.05) or placebo (16%, p0.01). Amlodipine treatment was associated with significantly fewer reports of headache and flushing than nifedipine retard (p0.05). The lower incidence and reduced severity of vasodilator side effects associated with amlodipine resulted in fewer withdrawals and a better overall tolerability profile.

Summary The usefulness of exercise Tl scintigraphy (combined with electrocardiography) in a district general hospital has been assessed in 80 patients in whom a previous exercise electrocardiogram (ECG) had not been definitive. Seventy-five of the patients presented with chest pain and five with no pain but an abnormal ECG. Case notes and test results were examined to establish the clinicians' judgment of the likelihood of having coronary heart disease (CHD) and the patient's outcome. The mean time of follow-up was 27 months. In the majority of patients the test was found to help the clinician come to a decision on the presence or absence of CHD. It was found to be particularly useful in patients with abnormal resting ECGs. There was a shorter time to discharge for patients classified as highly unlikely of having CHD. Only four patients were re-referred following discharge from the outpatient clinic. Nine patients were referred for coronary angiography with five being found to have significant stenosis. None of the 16 patients in whom the exercise ECG was normal had ischaemic myocardial segments in the Tl scintigraphy.

FELINE immunodeficiency virus (FIV) is a widespread pathogen of the domestic cat that is encountered most frequently in sick cats and is associated with a variety of clinical signs, especially gingivitis and respiratory signs (Hosie and others 1989). FIV infection is diagnosed by testing for anti-FIV antibodies and, following a positive diagnosis, veterinarians are required frequently to advise owners on the prognosis for an infected cat. Since FIV, like human immunodeficiency virus, has a long and variable disease course, it is often difficult to predict the outcome for an infected cat. Cats presented during the initial acute phase of infection may respond well to symptomatic treatment and subsequently may remain relatively healthy during the latent, asymptomatic phase of infection. In contrast, cats in the terminal or acquired immunodeficiency syndrome (AIDS) stage of infection display profound lymphoid depletion and will not respond to treatment (Matsumura and others 1993). A number of factors appear to influence the outcome of FIV infection. It has been shown that the effects of FIV infection are modulated by age, with reports of 100 per cent mortality in eight-week-old kittens infected with a lower dose of virus than leads to the development of a rapid disease course in 60 per cent of 12or 16-week-old cats (Diehl and others 1995). However, there have also been reports that FIV-infected cats can remain asymptomatic for several years (Kahler 1996), or even have a normal life expectancy (Addie and others 2000). Such reports contrast markedly with reports of severe immunodeficiency in infected cats (Pedersen and others 1987, Matsumura and others 1993). It has been suggested that such variable outcomes may arise because cats infected with the virus transmitted from symptomatic cats may progress more rapidly than cats infected with the virus from chronically infected, asymptomatic cats (Diehl and others 1995). Therefore, it is important to establish the outcomes of FIV infection that occur most frequently as a guide for veterinarians and owners of FIV-infected cats. In order to analyse the outcomes for cats recently diagnosed with FIV, a telephone survey of veterinary practices was undertaken in July 2000. The aim was to follow up 45 FIVinfected cats that tested seropositive for FIV following the submission of blood samples to the Feline Virus Unit at the University of Glasgow between February and June, 2000. Of the 45 veterinary surgeries contacted, 32 (71 per cent) were

Eleven endometrial biopsies, taken from six Turner's syndrome patients receiving hormone replacement therapy prior to treatment by oocyte donation and embryo transfer, were assessed by freeze fracture followed by electron microscopy for epithelial tight junctions. Nine of the eleven biopsies had no discernible tight junctions; the other two biopsies had reduced and disorganized junctional structures. Two patients subsequently became pregnant following embryo transfer. It is concluded that compromised epithelial integrity does not prevent embryo implantation in the human, an observation that is consistent with a barrier role for the epithelium except at times when appropriately conditioned with oestrogen and progesterone to induce receptivity for implantation.

Tight junctions between luminal epithelial cells of the human uterus were studied by freeze-fracture electron microscopy. It was found that junctional complexity decreased during the menstrual cycle, and we explore how this finding may contribute to the role of the uterus in facilitating implantation.

An antigen-specific feline T-lymphocyte cell line (Q201) was generated and infected in vitro with the feline immunodeficiency virus (FIV). Syncytium formation and the release of the viral core protein p24 into culture fluid were accompanied by a reduction in expression of the CD4 surface antigen. The reduction in CD4 expression was transient, the resulting persistently infected population of cells expressing levels of CD4 comparable to those observed prior to infection. Persistently infected cells gradually lost expression of major histocompatibility antigen (MHC) class II while maintaining pre-infection levels of expression of CD4, MHC class I, CD18 or CD29.

The pharmacokinetics of combined lisinopril and hydrochlorothiazide have been studied following single and multiple oral doses to 'young' (reference), elderly and renally impaired hypertensive patients. Tablets containing the fixed combination of lisinopril 20 mg and hydrochlorothiazide 12.5 mg were administered as a single dose followed by daily administration for 6-8 days. Serum concentration and haemodynamic measurements were made at intervals up to 48 hours after the first and last doses. The serum profiles of both drugs were comparable with observations from previous studies, showing higher concentrations in the elderly and in the renally impaired patients. Similar differences have been reported for such patient groups when the drugs were administered separately, indicating an absence of pharmacokinetic interaction. Both drugs accumulated by about 30% on multiple daily dosing. There were no differences between the patient groups in the extent of accumulation. The combination of lisinopril and hydrochlorothiazide produced the expected hypotensive response, minimum BP values being recorded 4 and 6 hours after treatment. The higher concentrations in the elderly and renally impaired patients were not associated with a greater reduction in BP. The pharmacokinetic behaviour of lisinopril and hydrochlorothiazide given together to elderly and renally impaired hypertensive patients suggests that a fixed dose combination is appropriate and that no changes to the dosage regimen additional to those used for the individual agents are necessary.

In this monotherapy study, 102 elderly hypertensive patients aged 65-80 years with a diastolic blood pressure (DBP) greater than or equal to 100 mmHg were randomized to double-blind treatment with felodipine 5 mg as an extended release (ER) formulation or placebo once daily. In patients with a DBP greater than 95 mmHg after two weeks the dose was doubled. Total treatment time was four weeks. Blood pressure and heart rate were measured 24 hours after dose intake. At the end of the study, supine BPs were reduced in comparison with values at randomization by 14/13 mmHg in the felodipine group and by 4/8 mmHg in the placebo group (P = 0.005/P = 0.007, felodipine vs. placebo). The proportion of responders was also significantly greater on felodipine than on placebo, 75% and 42%, respectively (response was defined as a reduction in supine DBP to less than or equal to 95 mmHg and/or a reduction by greater than or equal to 10 mmHg). A dose increase was performed in 41% of the patients on felodipine and in 50% on placebo. The proportion of patients reporting adverse events was low and of the same magnitude in both groups.

A single oral dose pharmacokinetic study in a group of 10 elderly healthy volunteers was performed to evaluate the pharmacokinetic profile and the potential effect of age on the absorption, distribution and elimination of droxicam. After complete medical screening, and informed written consent, one dose (20mg) of droxicam was administered to all volunteers, under medical supervision. A complete pharmacokinetic profile of the obtained blood plasma levels was evaluated over 120 hours. All volunteers completed the study and in none did droxicam cause intolerance or side effects. The results showed that droxicam absorption, distribution and elimination did not differ substantially from reference studies done with young healthy volunteers. The peak mean plasma concentration was at 10 hours 1.38 +/- 0.29 microgram/ml, declining slowly, reaching 0.24 +/- 0.20 microgram/ml at 120 hours, with a half life of 50.23 +/- 17.19 hours and an elimination rate constant of 0.015 +/- 0.005 microgram/ml.h-1. In comparison to the healthy, young volunteers, the variation was minimal. It can be concluded from this study that age causes minimal variations in the absorption and distribution of droxicam.

The glandular structure in the uterine epithelium of three groups of patients on standard superovulatory regimes was studied using a fully automated image analysis system. It was found that one treatment (buserelin stimulation) produced more glandular area than either of the other two. We suggest that buserelin gives the morphometric appearance of the most normal endometrial glands and find that our morphometric analysis is a reliable means to evaluate glandular structure in patients on superovulatory therapy.

In this double-blind, randomized, parallel-group study, the aim was to compare the efficacy and tolerability of a new fixed combination of felodipine and metoprolol with the individual components in monotherapy. After a placebo period of 4 weeks, 159 patients with mild to moderate essential hypertension were randomized to extended-release formulations of either felodipine plus metoprolol 10 + 100 mg (FM), felodipine 10 mg (F), or metoprolol 100 mg (M) once daily if supine diastolic blood pressure greater than 95 mm Hg. After 12 weeks of active treatment, the reductions in supine blood pressure (24 h after dosing) were 20/14, 13/10, and 11/8 mm Hg for FM, F, and M, respectively. The difference in change was 7/4 mm Hg (p = 0.004/p = 0.006) and 8/5 mm Hg (p = 0.0002/p less than 0.0001) for the fixed combination and F or M, respectively. Blood pressure control (diastolic blood pressure less than 90 mm Hg after 12 weeks) was significantly better for the combination than for F and M, i.e., 71%, 49% (p = 0.008), and 34% (p = 0.004), respectively. Adverse experiences were those to be expected from previous studies with felodipine and metoprolol and did not differ in frequency between groups. It can be concluded that a fixed combination of metoprolol and felodipine has a clinically relevant and significantly better blood pressure reduction 24 h postdose than the individual substances in monotherapy, without decreased tolerability.

A new design of gamma-ray computed tomography (CT) scanner was used to measure bone density in 516 normal adults and in 116 female patients with osteoporotic fractures. Trabecular bone density (TBD) was measured for a core of the ultradistal radius; cortical bone mass per unit length (MLS) and mass per unit volume (MVS) were computed for the radius shaft. TBD, MLS and MVS peaked at the age of about 40 in females and fell by 32%, 15% and 24%, respectively, by the age of 65. In males, TBD decreased from the third decade and MLS and MVS peaked in the fourth decade. The corresponding falls by 65 years were 20%, 6% and 7%. In patients with Colles' fracture TBD and MLS were reduced by 13% and 10%, respectively, relative to age matched normal female subjects. For patients with vertebral crush fracture the reductions relative to age matched normal females were 36%, 17% and 16% for TBD, MLS and MVS. In fracture patients the deficit in TBD was significantly greater than that for cortical bone but TBD was no better at discriminating normal and osteoporotic individuals because of its larger normal range. We conclude that gamma-ray CT may best be used for monitoring changes in bone rather than as a diagnostic screening tool.