Treatment adherence to olfactory training: a real-world observational study

BACKGROUND

Olfactory training (OT) is considered an effective intervention for most causes of smell loss and is recommended as a long-term treatment. However, the treatment adherence of OT remains unclear. This study aims to identify the frequency and causalities for lack of adherence to OT.

METHODS

In this prospective study, 53 patients previously diagnosed with olfactory dysfunction (OD), who were recommended to perform OT, were enrolled. Patients underwent olfactory testing using Sniffin' Sticks for threshold, discrimination, and identification (TDI) and a subjective numeric rating scale (NRS) at a baseline and follow-up visit. In addition, patients answered a six-item treatment adherence questionnaire. The primary outcome measures were clinically relevant improvements according to the TDI (>=5.5) and NRS (>=5.5) scores.

RESULTS

Out of 53 patients, 45 performed OT. Among patients who performed OT, 31% discontinued the use of OT on their own due to a self-perceived improvement, while 51% discontinued use due to lack of improvements in olfaction. In these patients, the average duration of OT use was five months. After controlling for baseline duration of OD, baseline TDI score and smell loss aetiologies, discontinuing OT due to a lack of self-perceived improvement remained significantly associated with worse TDI and NRS outcomes at follow-up.

CONCLUSIONS

Our data show that therapeutical adherence to OT is low, regardless of patients' perception of olfactory function. Olfactory improvement leads to decreased training due to satisfaction, while lack of improvement leads to non-adherence based on disappointing subjective outcome. Patients should be advised to perform OT consistently.

Caseinolytic mitochondrial matrix peptidase X is essential for homologous chromosome synapsis and recombination during meiosis of male mouse germ cells

ABSTRACT

Meiosis is the process of producing haploid gametes through a series of complex chromosomal events and the coordinated action of various proteins. The mitochondrial protease complex (ClpXP), which consists of caseinolytic mitochondrial matrix peptidase X (ClpX) and caseinolytic protease P (ClpP) and mediates the degradation of misfolded, damaged, and oxidized proteins, is essential for maintaining mitochondrial homeostasis. ClpXP has been implicated in meiosis regulation, but its precise role is currently unknown. In this study, we engineered an inducible male germ cell-specific knockout caseinolytic mitochondrial matrix peptidase X (ClpxcKO) mouse model to investigate the function of ClpX in meiosis. We found that disrupting Clpx in male mice induced germ cell apoptosis and led to an absence of sperm in the epididymis. Specifically, it caused asynapsis of homologous chromosomes and impaired meiotic recombination, resulting in meiotic arrest in the zygotene-to-pachytene transition phase. The loss of ClpX compromised the double-strand break (DSB) repair machinery by markedly reducing the recruitment of DNA repair protein RAD51 homolog 1 (RAD51) to DSB sites. This dysfunction may be due to an insufficient supply of energy from the aberrant mitochondria in ClpxcKO spermatocytes, as discerned by electron microscopy. Furthermore, ubiquitination signals on chromosomes and the expression of oxidative phosphorylation subunits were both significantly attenuated in ClpxcKO spermatocytes. Taken together, we propose that ClpX is essential for maintaining mitochondrial protein homeostasis and ensuring homologous chromosome pairing, synapsis, and recombination in spermatocytes during meiotic prophase I.

Efficacy and safety of switching between biologics in chronic rhinosinusitis with nasal polyps or N-ERD

BACKGROUND AND OBJECTIVE

The effectiveness of biologics in chronic rhinosinusitis with nasal polyps (CRSwNP) is well-established. However, real-world experience on the effectiveness of transitioning between two monoclonal antibodies is scarce. Therefore, we aimed to analyze the safety and efficacy of antibody switching in treatment of chronic rhinosinusitis.

METHODS

All patients with CRSwNP or nonsteroidal anti-inflammatory drugs-exacerbated respiratory disease (N-ERD) requiring a switch between biologics were retrospectively studied. Analysis included changes in polyp size, quality of life parameters, asthma control, and side effects.

RESULTS

Out of 195 patients treated with biologics for CRSwNP or N-ERD in our center, 23 (11.8%) required transition to a different monoclonal antibody. The majority switched from omalizumab to dupilumab (17/23, 73.9%), mostly due to inadequate symptom control. Nine out of these 17 patients (52.9%) were switched without a washout period. All patients showed significant improvement in nasal polyp score, asthma control test and sino-nasal outcome test-22 after changing to dupilumab. Keratoconjunctivitis sicca was the side-effect (4.3%) reported after the switch from omalizumab to dupilumab, which lead to termination of therapy in one patient. Due to limited sample size, other antibody transitions were reported in a descriptive manner.

CONCLUSION

The transition to dupilumab is an effective option in patients with inadequate treatment response or side-effects of omalizumab in nasal polyposis. Our preliminary results indicate that a wash-out period may not be necessary when switching between biologics, however, these findings require further investigations. Other monoclonal antibody transitions also show promising results, but warrant validations in larger cohorts due to small patient samples in our study.

[Clinical features and CT findings of fibrosing mediastinitis associated pulmonary hypertension]

Objective: To investigate the clinical features and CT findings of pulmonary hypertension (PH) in patients with fibrosing mediastinitis (FM). Methods: Thirteen patients with FM diagnosed between September 2015 and June 2022 were studied retrospectively, including patients with PH (FM-PH group) and patients without PH (FM group) confirmed on right heart catheterization. The t test of two independent samples, Mann-Whitney U rank sum and Fisher's test were used to compare the general information, symptoms, laboratory examination, right ventricular and pulmonary artery measurement data and pulmonary artery CT findings between the two groups, respectively. Results: Compared with the 7 FM patients aged 28-79 (60.00±17.69) years, the 6 patients in the FM-PH group, aged from 60 to 82 (68.83±8.35) years, had more peripheral edema, lower percentage of PaO₂, wider inner diameters of pulmonary artery and right ventricle, a higher ratio of right ventricle and left ventricular transverse diameter, faster tricuspid regurgitation velocity and higher estimated systolic pulmonary artery pressure (P<0.05). There were no differences in BNP levels and tricuspid annular plane systolic excursion between groups (P>0.05). Of the 6 patients with PH, 5 had precapillary PH and 1 had mixed PH. Except that the pulmonary vascular resistance in patients of the FM-PH group was significantly higher than that in the FM group (P<0.05), there were no significant differences in cardiac output, mixed venous oxygen saturation and pulmonary capillary wedge pressure between the two groups. CT pulmonary angiography (CTPA) showed pulmonary artery and vein stenosis. Patients in the FM-PH group had more severe stenosis and occlusion of pulmonary artery and pulmonary vein (P<0.05), and more involvement of multiple pulmonary veins (P<0.05). Conclusions: The clinical manifestation of FM complicated with PH is related to the degree of involvement of pulmonary artery, vein and airway. It is recommended that the disease be evaluated in combination with multiple parameters such as clinical manifestations, cardiac ultrasound, right cardiac catheter and CTPA.

Extreme weather conditions influence the frequency of epistaxis-related emergency room visits

BACKGROUND

Climate change has been associated with an increase in extreme weather conditions. The aim of this study was to identify environmental factors and the effect of extreme weather events (95th percentile) on the risk for epistaxis-related emergency room visits (EV).

METHODS

A total of 2179 epistaxis-related EVs were identified between 2015 and 2018. A distributed lag non-linear model was fitted to investigate the relationship between extreme weather conditions and the total number of epistaxis-related EVs per day. Cumulative relative risk (cRR) is defined as the cumulated daily risk of EV for epistaxis within a stated period after an extreme weather condition compared to the risk of EV at the median value of that weather condition.

RESULTS

At a mean daily temperature of 27°C (P95), cRR for epistaxis-related EV was 2.00. At a relative humidity of 39% (P5), cRR was highest on day 3 at 1.59, while extremely high humidity (92%, P99) led to a decreased cRR of 0.7 on day 1. Intense precipitation of 24mm (P99) reduced the cRR on day 3 to 0.38. For prolonged extreme conditions over three days, extremely low wind speed, as well as both high and low atmospheric pressure events, diminished cRR.

CONCLUSIONS

Extreme temperatures, relative humidity, and precipitation, as well as extended periods of extreme wind speeds and atmospheric pressure, significantly impact cRR for epistaxis-related EVs.

Multi-institutional minimal clinically important difference of the 22-item Sinonasal Outcome Test in medically managed chronic rhinosinusitis

BACKGROUND

With a rapid proliferation of clinical trials to study novel medical treatments for CRS, the objective of this study was to study the minimal clinically important difference (MCID) of the 22-item Sinonasal Outcome Test (SNOT-22) in medically-managed CRS patients.

METHODS

A total of 183 medically-treated CRS patients were recruited. All patients completed a SNOT-22 at enrollment and subsequent follow up visit. Distribution and anchor-based methods were used for MCID calculation. These data were combined with data from a previously published study on SNOT-22 MCID in 247 medically managed CRS patients to determine a final recommended MCID value using the combined cohort of 430 patients.

RESULTS

In our cohort, distribution- and anchor-based methods-using both sinus-specific and general health anchors-provided greatest support for a 12-point SNOT-22 MCID, which had approximately 55% sensitivity but 81% specificity for detecting patients explicitly reporting improvement in their sinus symptoms and general health. In the combined cohort of 430 patients, we also found greatest support for a 12-point SNOT-22 MCID, which had approximately 57% sensitivity and 81% specificity for detecting patients explicitly reporting improvement in their sinus symptoms and general health. We also find evidence that the MCID value may be higher in CRS patients without nasal polyps compared to those with nasal polyps.

CONCLUSIONS

Our results - which include data from patients from two different institutions and regions - confirm a SNOT-22 MCID of 12 in medically managed CRS patients. The SNOT-22 MCID was specific but not sensitive for identifying CRS patients experiencing improvement in symptoms or general health.

Individual importance of olfaction decreases with duration of smell loss

BACKGROUND

The personal importance of a lost neurologic - motor or sensory - function in several conditions has been shown to decrease as the afflicted patient becomes accustomed to not having that function. It is unknown how the importance of olfaction changes with duration of olfactory dysfunction (OD). The aim of this study was to evaluate the association between duration of smell loss and individual significance of olfaction, and whether this relationship would be modulated by other factors, such as etiology of smell loss.

METHODS

This is a retrospective study including a total 163 subjects with different degrees of olfactory function. Individual significance of olfaction was measured using the Importance of Olfaction Questionnaire (IOQ). Demographics, olfactory function, duration and etiology of OD were evaluated. Group comparisons, bivariate correlations, analyses of variance and multivariate linear regression were applied to detect differences and associations with the outcome measure of IOQ.

RESULTS

A significant negative correlation was found between duration of OD and the IOQ. Other important findings include a significantly higher IOQ in patients with posttraumatic- compared to idiopathic OD and in patients with higher aggravation scores compared to the lower aggravation group. Multivariate regression analysis further confirmed that duration of smell loss was independently associated with IOQ.

CONCLUSIONS

The duration of smell loss is negatively correlated with the individual importance of olfaction, suggesting that patients develop coping mechanisms for adjusting to OD.

Factors associated with relevant olfactory recovery after olfactory training: a retrospective study including 601 participants

OBJECTIVE

Olfactory training (OT) represents a therapeutic option for multiple etiologies of olfactory dysfunction (OD) that also benefits normosmic subjects. In this retrospective study, we report the effectiveness of OT and factors associated with relevant changes in olfactory function (OF) in large groups of normosmic participants and patients with OD, including a control group that performed no training.

METHODS

This was a retrospective pooled analysis including 2 treatment cohorts of 8 previously published studies. Adult participants that either presented with the major complaint of quantitative OD or normosmic volunteers were recruited at various ENT clinics and received OT or no training. The outcome was based on changes in objective olfactory test scores after OT.

RESULTS

A total of 601 patients with OD or normosmic subjects were included. OT was more effective compared to no training. No interaction was found between OT and OF. In multivariate analysis, higher baseline OF (adjusted odds ratio, aOR, 0.93) and posttraumatic (aOR, 0.29) or idiopathic OD (aOR, 0.18) compared to postinfectious causes were significantly associated with lower odds of relevant improvements in patients with OD receiving OT. Subgroup analysis of normosmic participants receiving OT further revealed a significant association of lower age and baseline olfactory function with improvements of overall OF.

CONCLUSIONS

This study demonstrated that OT was more effective than no training in patients with various causes of OD. Additionally, baseline olfactory performance and etiology of OD were identified as important factors associated with relevant improvements after OT.

Factors associated with relevant olfactory recovery after olfactory training: a retrospective study including 601 participants

BACKGROUND

Olfactory training (OT) represents a therapeutic option for multiple etiologies of olfactory dysfunction (OD) that also benefits normosmic subjects. In this retrospective study, we report the effectiveness of OT and factors associated with relevant changes in olfactory function (OF) in large groups of normosmic participants and patients with OD, including a control group that performed no training.

METHODS

This was a retrospective pooled analysis including 2 treatment cohorts of 8 previously published studies. Adult partici- pants that either presented with the major complaint of quantitative OD or normosmic volunteers were recruited at various ENT clinics and received OT or no training. The outcome was based on changes in objective olfactory test scores after OT.

RESULTS

A total of 601 patients with OD or normosmic subjects were included. OT was more effective compared to no training. No interaction was found between OT and OF. In multivariate analysis, higher baseline OF (adjusted odds ratio, aOR, 0.93) and posttraumatic (aOR, 0.29) or idiopathic OD (aOR, 0.18) compared to postinfectious causes were significantly associated with lower odds of relevant improvements in patients with OD receiving OT. Subgroup analysis of normosmic participants receiving OT further revealed a significant association of age and baseline olfactory function with improvements of overall OF.

CONCLUSIONS

This study demonstrated that OT was more effective than no training in patients with various causes of OD. Additi- onally, baseline olfactory performance and etiology of OD were identified as important factors associated with relevant improve- ments after OT.

Plasma VEGF - a candidate biomarker for response to treatment with bevacizumab in HHT patients

BACKGROUND

Recurrent epistaxis is the principal symptom of hereditary hemorrhagic telangiectasia (HHT). Currently, there is no standard therapy for this condition. Bevacizumab (anti-VEGF) treatment has been under intense investigation but treatment effects vary greatly between individuals. There are currently no markers to predict anti-VEGF therapeutic response in HHT patients.

METHODS

We evaluated plasma VEGF levels in 13 HHT patients and correlated values with i) degree of epistaxis, measured by visual analog scale (VAS), epistaxis severity score (ESS), and patient bleeding diaries ii) the prevalence of extranasal manifestations, iii) the HHT subtype and iv) the treatment response to intranasal submucosal bevacizumab.

RESULTS

Plasma VEGF was elevated in all 13 HHT patients compared to reference levels and showed a moderate correlation with VAS and duration of moderate bleeding events. In patients treated with intranasal submucosal bevacizumab plasma VEGF levels showed a strong correlation with the degree of reduction of mild bleeding events and VAS.

CONCLUSIONS

The role of plasma VEGF as a potential predictive biomarker for therapeutic response to bevacizumab treatment warrants further investigation in larger prospective studies.

Impaired oocyte maturation and ovulation in membrane progestin receptor (mPR) knockouts in zebrafish

Accumulating evidence suggest that membrane progestin receptor α (mPRα) is the membrane receptor mediating nongenomic progestin signaling that induces oocyte maturation in teleost. However, the involvement of other members of mPR family in oocyte maturation is still unclear. In this study, we found impaired oocyte maturation in zebrafish lacking mPRα1, mPRα2, mPRβ, or mPRγ2. In contrast, no difference was observed in oocyte maturation in the single knockout of mPRγ1, mPRδ, or mPRε. To study possible redundant functions of different mPRs in oocyte maturation, we generated a zebrafish line lacking all seven kinds of mPRs (mprs^-/-). We found oocyte maturation was further impaired in mprs^-/-. In addition, oocyte ovulation delay was observed in mprs^-/- females, which was associated with low levels of nuclear progestin receptor (Pgr), a key regulator for ovulation. We also found reduced fertility in mprs^-/- female zebrafish. Furthermore, eggs spawned by mprs^-/- females were of poor quality.

A cryogen-free dilution refrigerator based Josephson qubit measurement system

We develop a small-signal measurement system on cryogen-free dilution refrigerator which is suitable for superconducting qubit studies. Cryogen-free refrigerators have several advantages such as less manpower for system operation and large sample space for experiment, but concern remains about whether the noise introduced by the coldhead can be made sufficiently low. In this work, we demonstrate some effective approaches of acoustic isolation to reduce the noise impact. The electronic circuit that includes the current, voltage, and microwave lines for qubit coherent state measurement is described. For the current and voltage lines designed to have a low pass of dc-100 kHz, we show that the measurements of Josephson junction's switching current distribution with a width down to 1 nA, and quantum coherent Rabi oscillation and Ramsey interference of the superconducting qubit can be successfully performed.

Epidemiology of acute primary angle-closure glaucoma in the Hong Kong Chinese population: prospective study

OBJECTIVES

To determine the incidence of acute primary angle-closure glaucoma in the Hong Kong Chinese population, and to identify risk factors for this condition.

DESIGN

Prospective study.

SETTING

University teaching hospital, Hong Kong.

PARTICIPANTS

Patients with acute primary angle-closure glaucoma presenting between 1 March 1998 and 29 February 2000.

MAIN OUTCOME MEASURES

Demographic data, presenting symptoms and signs, temporal details of the presentation, and precipitating factors. The crude regional incidence was calculated according to the Hong Kong population census of 1991 and the age-specific incidence was calculated.

RESULTS

Seventy-two cases (72 eyes of 72 patients) of acute primary angle-closure glaucoma were recruited. The crude incidence was 10.4 per 100,000 per year in the population aged 30 years and older. Patients at higher risk of attacks were those aged 70 years or older (age-specific incidence, 58.7 per 100,000 per year) and females, who had a relative risk of 3.8 compared with males (95% confidence interval, 1.7-8.4). Only four (5.6%) patients had a positive family history of acute primary angle-closure glaucoma. Seventeen (23.6%) patients were noted to have an upper respiratory tract infection before the attack, and 25 (34.7%) patients had taken antitussive agents. There was a statistically significant inverse correlation between the monthly attack rate and the monthly rate of influenza (Spearman's rank correlation coefficient = -0.388; P=0.031).

CONCLUSION

There is a high incidence of acute primary angle-closure glaucoma among Chinese residents of Hong Kong, with elderly females at highest risk. A significant proportion of patients reported upper respiratory tract infection or the use of antitussive medication prior to attacks.

Genital infection and termination of pregnancy: Are patients still at risk?

OBJECTIVES

To identify the treatment patterns and early complication rates in women identified with a genital infection prior to a termination of pregnancy (TOP) and to re-assess our earlier work on contact attendance and treatment. The aim was to refine current prophylactic measures to provide the most efficient and effective way of reducing post-termination complications.

METHOD

Six-month retrospective analysis of all women with genital Chlamydia trachomatis or Neisseria gonorrhoeae identified prior to TOP. Data on the timing of positive results and treatment in relation to the TOP were recorded. Clinical signs of pelvic infection and the success of contact tracing and treatment were noted.

RESULTS

Forty women were identified with infection, 31 (78%) proceeded to TOP; only five were treated adequately in the peri-TOP period. Twenty-six (84%) of the women undergoing TOP attended the genitourinary medicine (GUM) department after the TOP and received antimicrobial therapy where necessary. In total, four women (10%) were untreated. Approximately two thirds of results were reported prior to, or on the day of, the TOP. The majority of TOPs (71%) were carried out at 5 days or less from the initial assessment. Clinical signs of post-TOP pelvic inflammation developed in seven (28%) women with chlamydial infection. Contact tracing was successful in 24 (69%) of the 35 women who attended the GUM department.

CONCLUSION

The debate about the best option for the most effective management of women undergoing TOP continues. The options with respect to C. trachomatis include universal prophylaxis, screening and treating as necessary, or a 'belt and braces' approach of screening all and treating all. Fundamental is the continuation of active contact tracing and GUM remains integral to this.

Constraining ligand-binding site stoichiometry suggests that a cyclic nucleotide-gated channel is composed of two functional dimers

Cyclic nucleotide-gated ion channels are composed of four pore-forming subunits. Binding of cyclic nucleotide to a site in the intracellular carboxyl terminus of each subunit leads to channel activation. Since there are four subunits, four binding events are possible. In this study, we investigate the effects of individual binding events on activation by studying channels containing one, two, three, or four functional binding sites. The binding of a single ligand significantly increases opening, although four ligands are required for full activation. The data are inconsistent with models in which the four subunits activate in a single concerted step (Monod-Wyman-Changeux model) or in four independent steps (Hodgkin-Huxley model). Instead, the four subunits may associate and activate as two independent dimers.

Identification of a gene encoding a hyperpolarization-activated pacemaker channel of brain

The generation of pacemaker activity in heart and brain is mediated by hyperpolarization-activated cation channels that are directly regulated by cyclic nucleotides. We previously cloned a novel member of the voltage-gated K channel family from mouse brain (mBCNG-1) that contained a carboxy-terminal cyclic nucleotide-binding domain (Santoro et al., 1997) and hence proposed it to be a candidate gene for pacemaker channels. Heterologous expression of mBCNG-1 demonstrates that it does indeed code for a channel with properties indistinguishable from pacemaker channels in brain and similar to those in heart. Three additional mouse genes and two human genes closely related to mBCNG-1 display unique patterns of mRNA expression in different tissues, including brain and heart, demonstrating that these channels constitute a widely expressed gene family.

A state-independent interaction between ligand and a conserved arginine residue in cyclic nucleotide-gated channels reveals a functional polarity of the cyclic nucleotide binding site

Activation of cyclic nucleotide-gated channels is thought to involve two distinct steps: a recognition event in which a ligand binds to the channel and a conformational change that both opens the channel and increases the affinity of the channel for an agonist. Sequence similarity with the cyclic nucleotide-binding sites of cAMP- and cGMP-dependent protein kinases and the bacterial catabolite activating protein (CAP) suggests that the channel ligand binding site consists of a beta-roll and three alpha-helices. Recent evidence has demonstrated that the third (or C) alpha-helix moves relative to the agonist upon channel activation, forming additional favorable contacts with the purine ring. Here we ask if channel activation also involves structural changes in the beta-roll by investigating the contribution of a conserved arginine residue that, in CAP and the kinases, forms an important ionic interaction with the cyclized phosphate of the bound ligand. Mutations that conserve, neutralize, or reverse the charge on this arginine decreased the apparent affinity for ligand over four orders of magnitude but had little effect on the ability of bound ligand to open the channel. These data indicate that the cyclized phosphate of the nucleotide approaches to within 2-4 A of the arginine, forming a favorable ionic bond that is largely unaltered upon activation. Thus, the binding site appears to be polarized into two distinct structural and functional domains: the beta-roll stabilizes the ligand in a state-independent manner, whereas the C-helix selectively stabilizes the ligand in the open state of the channel. It is likely that these distinct contributions of the nucleotide/C-helix and nucleotide/beta-roll interactions may also be a general feature of the mechanism of activation of other cyclic nucleotide-binding proteins.

Hypotensive effects of peptide T in conscious rats

1. The present study investigated the effects of peptide T on mean arterial blood pressure (MAP) in conscious normotensive Sprague-Dawley (SD) rats, spontaneously hypertensive rats (SHR) and two-kidney one-clip (2K1C) hypertensive rats. 2. Peptide T was infused via the left jugular vein at a rate of 1 mg/kg per h in SD, SHR and 2K1C rats and then at doses of 0.1, 0.25, 0.5, 1 and 5 mg/kg per h in SHR, with 0.9% saline as a sham control in SHR and 2K1C. Mean arterial pressure was measured directly before, during and after infusion. 3. Peptide T (1 mg/kg per h) decreased blood pressure in both SHR (P < 0.01) and 2K1C (P < 0.05). In normotensive SD rats the fall in MAP approached statistical significance (P = 0.06). The effect of peptide T was not significantly different in normotensive compared with hypertensive rats. Saline infusion had no effect. The blood pressure lowering effect of peptide T appeared to be dose-dependent in SHR.

Does angiotensin play a role in human fetal erythropoiesis?

Angiotensin affects the growth of many cell types and there have been suggestions that it could influence cells which respond to erythropoietin. During first trimester, human fetal haematopoietic cells are exquisitely responsive to erythropoietin and we have assessed the potential for angiotensin to also influence the growth of these cell types in a standard culture system. The data obtained from these studies indicate that angiotensin does not influence fetal haematopoiesis over a range of concentrations.

Isolation of fetal trophoblasts and nucleated erythrocytes from the peripheral blood of pregnant women for prenatal diagnosis of fetal aneuploides

We present the results of a study of fetal cell isolation from the peripheral blood of 46 women in the first trimester of pregnancy. The trophoblasts were sorted with paramagnetic beads labelled with a novel monoclonal antibody 340 (Mab340) (Durrant et al., Prenat. Diagn., 14 (1994) 131). This was followed by triple density gradient enrichment to remove maternal lymphocytes and red blood cells. Nucleated red blood cells (NRBC) were sorted by incubation with ferromagnetic particles coated with Mab CD71, an antitransferrin receptor monoclonal antibody, and separation on a mini-MACS column. Sorted cells were sexed using nested PCR for the Y chromosome and the results compared with the karyotypic analysis of the CVS. The sensitivity in determining a male pregnancy with NRBC alone was 38% and with trophoblasts alone was 39%. Sorting for both cell types correctly predicted a male pregnancy in 10/18 or 56%. Of the 10 males correctly identified, 3 were diagnosed on NRBC alone, 3 on trophoblast alone and 4 with both cell types. As there are very few fetal cells in maternal blood, sorting for both will increase the yield and improve diagnosis. However the technique requires further development to improve sensitivity.

Gestational age and cell viability determine the effect of frozen storage on human fetal hematopoietic progenitor cell preparations

We have assessed hematopoietic progenitor cell preparations (including CD34-positive stem cells) obtained from human fetal liver at 6-17 weeks of gestational age for total cell numbers, viability and the ability to tolerate (frozen) storage. Hematopoietic cell preparations obtained from the 16-to 17-week gestational age range had the highest total cell count and the greatest proportion of CD34-positive stem cells. However, these preparations were insufficiently robust to withstand the freeze/thaw protocol required. Cells obtained from the 13- to 15-week gestational age range showed optimal post-thaw viability and it is suggested that these cell preparations are the most applicable for in utero transplantation.

Reduction in erythrocyte complement receptor 1 (CR1, CD35) and decay accelerating factor (DAF, CD55) during normal pregnancy

RBC-membrane CR1 has been assayed in pregnancy and at 48 h postpartum. It has been shown that RBC CR1 is reduced as pregnancy progress, reaching a nadir in the third trimester and that it returns to levels approaching normal within 48 h postpartum. Further, there is a reduced expression of RBC decay accelerating factor (DAF) during pregnancy but no change in expression of RBC CD59. We suggest that the reduction in RBC CR1 and DAF may reflect increased levels of circulating immune complexes and consequent increased complement activation in pregnancy.

Prenatal diagnosis in Treacher Collins syndrome using combined linkage analysis and ultrasound imaging

Treacher Collins syndrome is an autosomal dominant disorder of facial development, the features of which include conductive hearing loss and cleft palate. In the current investigation, linkage analysis has been used to make first trimester diagnostic predictions in a pregnancy at high risk of producing an affected child. The results of this analysis predicted that the child would be affected. As predictions of the severity of the disease were not possible, the pregnancy was also assessed by ultrasound imaging. This confirmed the affected diagnosis and predicted that the child would be severely affected.

Denervation, but not decentralization, reduces nerve growth factor content of the mesenteric artery

In the present study we applied an improved nerve growth factor (NGF) extraction method to examine the effects of denervation and sympathetic decentralization on NGF levels in vascular tissue. Adult male Wistar Kyoto rats underwent mesenteric arterial denervation or splanchnic nerve transection. Four days after operation, animals were killed, and the mesenteric artery and coeliac-superior mesenteric ganglia were removed. The arterial adventitia was stripped from the media to measure NGF levels in nerve and smooth muscle separately. A high concentration of NGF was detected in the normal artery, 90% of which was in the adventitial layer. Surgical denervation significantly reduced the NGF levels in the artery and ganglia by 78 and 71%, respectively. However, within the artery the level of NGF was reduced in the adventitia but not in the media. Thus, the large reduction of NGF content resulted from the loss of nerve plexus from the artery. In contrast, decentralization did not alter the NGF content in the artery, in either the adventitia or media. Our results are in marked contrast to previous studies reporting elevated levels of NGF following denervation. This discrepancy is explained by the ability of our new procedure to extract much greater amounts of NGF from the tissue.

Angiotensin converting enzyme inhibition and protein restriction in progression of experimental chronic renal failure

This study examined whether the effects of protein restriction and angiotensin converting enzyme (ACE) inhibition on the progression of renal failure are common or additive. Male Sprague Dawley rats (12 wks of age) underwent 5/6 nephrectomy and were randomized to 20% protein diet (PD) (n = 9), 20% PD+enalapril (5 mg/kg/day) (n = 10), 20% PD+felodipine (30 mg/kg/day) (n = 9), 6% PD (n = 9), 6% PD+enalapril (n = 9) or 6% PD+felodipine (n = 10). Protein restriction, enalapril or felodipine treatment all retarded progression of renal failure and development of glomerular lesions. Protein restriction and enalapril appeared to have additive effects in preventing glomerular sclerosis.

Subunit stoichiometry of cyclic nucleotide-gated channels and effects of subunit order on channel function

Cyclic nucleotide-gated (CNG) ion channels are multimeric structures containing at least two subunits. However, the total number of subunits per functional channel is unknown. To determine the subunit stoichiometry of CNG ion channels, we have coexpressed the 30 pS conductance bovine retinal channel (RET) with an 85 pS conductance chimeric retinal channel containing the catfish olfactory channel P region (RO133). When RO133 and RET monomers are coexpressed, channels with four distinct intermediate conductances are observed. Dimer constructs reveal that two of these conductance levels arise from channels with the same subunit composition (2 RO133:2 RET) but distinct subunit order (like subunits adjacent to each other versus like subunits across from each other). Thus, the data demonstrate that cyclic nucleotide-gated ion channels are tetrameric like the related voltage-gated potassium ion channels; the order of subunits affects the conductance of the channel; and the channel has 4-fold symmetry in which four asymmetric subunits assemble head to tail around a central axis.

The role of serotonin in preeclamptic hypertension. A review and case report

Generalized arteriolar vasospasm and subsequent damage to vascular endothelium are fundamental to the development of preeclampsia. A possible mechanism underlying this involves increased deportation of trophoblast cells into maternal venous circulation with 5-hydroxytryptamine (serotonin, 5-HT) release as a consequence of platelet aggregation onto these fragments. Ketanserin, a 5-HT(2) receptor blocker, has been used successfully to treat preeclampsia. An examination of the therapeutic role of ketanserin indicates that there should now be a much more detailed assessment of serotonin antagonists in the treatment and prophylaxis of preeclampsia and eclampsia.

Pregnancy care of the low risk woman: the community-hospital interface

Aims to determine the extent to which women suitable for community-based antenatal and intrapartum care will require hospital contact. Reports on an historical cohort study of low risk women who underwent standard shared care and for whom the records for both pregnancy and delivery were complete at The City Hospital and University Hospital, Nottingham. Concludes that the shift to community-based care aims to bring many improvements to the overall care and satisfaction of pregnant women. However, it may not reduce the workload of hospital-based services to a great extent as the majority of women, even if low risk at booking, will require some hospital input at some time during pregnancy or labour.

Endometrial leukocyte subpopulations in women with endometriosis

The aim of this study was to investigate whether the endometrium of women with endometriosis differs immunologically from the endometrium of normal fertile women. Endometrial biopsies were obtained from 18 normal fertile women who were requesting sterilisation or reversal of sterilisation and 21 infertile women who had laparoscopically diagnosed pelvic endometriosis. The endometrial biopsies were obtained from both groups during the either early, mid or late luteal phase of the menstrual cycle. A panel of 11 monoclonal antibodies and immuno-histochemical techniques were employed to characterise the endometrial stromal leukocytes in frozen sections. Image analysis was used for semi quantitation of leukocytes. In both groups, the number of endometrial granulated lymphocytes (CD56+ CD38+ cells) and macrophages (CD68+ cells) increased significantly between the early and late luteal phase of the menstrual cycle. Compared with fertile controls, women with endometriosis had fewer T-suppressor/cytotoxic (CD8+) cells and endometrial granulated lymphocytes but more T-helper/inducer (CD4+) cells, CD68+ cells and CD16+ cells. None of these differences reached a statistically significant level. This study has shown that the endometrial lymphoid tissue of women with endometriosis does not differ qualitatively or quantitively from that of normal fertile controls. However, functional differences of endometrial leukocytes between the two groups cannot be excluded.

Renin mRNA, quantified by polymerase chain reaction, in renal hypertensive rat tissues

To determine responses in renin gene expression in different tissues of two-kidney, one clip hypertensive Sprague-Dawley rats and the effect of NaCl loading, we developed a novel, highly sensitive quantitative polymerase chain reaction technique and measured renin mRNA at 19 and 40 days after clipping. Basal renin mRNA concentrations were 1575 +/- 127 fg/micrograms total RNA in kidney, 52 +/- 7 in hypothalamus, 7.9 +/- 0.7 in adrenal, and 4.7 +/- 0.5 in atria. In two-kidney, one clip rats, renin mRNA in the clipped kidney was increased 5.4-fold (P = .00001) and 2.3-fold (P = .001) on each respective day after clipping and in the unclipped kidney was decreased by 27% (P = .01) and 38% (P = .04). In adrenal, 3.9-fold (P = .004) and 1.7-fold (P = .02) increases were seen on days 19 and 40, respectively, and a decrease of 57% (P = .02) was found in a hypothalamic block at day 19 but not at day 40. The decrease in hypothalamus was abolished by 1% oral NaCl, which reduced renin mRNA by 37% in the clipped kidney and by 30% in the adrenal but did not lead to any change in the unclipped kidney or hypothalamus at day 40. Hypothalamic renin mRNA was also decreased by enalapril compared with increases of sixfold to ninefold in other tissues. In conclusion, we have quantified a decrease in hypothalamic renin mRNA in two-kidney, one clip rats 19 days after clipping that can be abolished by NaCl loading, whereas in the adrenal, renin mRNA was increased. Similar relative tissue-specific changes were also seen in enalapril-treated rats.

Long-term storage of human fetal haematopoietic progenitor cells and their subsequent reconstitution. Implications for in utero transplantation

Haematopoietic progenitor cells were isolated from human fetal liver, obtained between 6 and 15 weeks gestation. After preparation of a single cell suspension, the cells were stored using a stepwise freezing protocol; taking the cells from room temperature through -70 degrees C to liquid nitrogen. Viability (trypan blue exclusion), morphology (Leishman stain), identification of cell type (flow cytometry) and growth characteristics in semi-solid culture medium were assessed using the fresh cell suspension. We were able to confirm that the predominant cells in human fetal liver up to about 15 weeks gestation are those of the erythroid lineage. It was established that viability in excess of 75% was required to ensure adequate growth in culture after frozen storage and it was deemed important to ensure morphological integrity of the cell preparations. The colonies formed in culture were observed to be producing haemoglobin between 7 and 9 days after initial seeding. We have determined that cells can be stored in liquid nitrogen for up to 2 years without loss of (1) viability, (2) morphological features and (3) ability to form colonies and produce haemoglobin in culture. These findings offer encouragement for the implementation of a cell bank to support an in utero transplantation programme.

Renin mRNA concentration in rat hypothalamus is decreased by enalapril

1. Renin mRNA is expressed in several extrarenal tissues, including brain. The aim of the present study was to quantify renin mRNA in the hypothalamus in response to a low NaCl diet and angiotensin converting enzyme inhibitor treatment, both of which are well-known stimuli of renin mRNA in kidney. 2. Groups of six Sprague-Dawley rats were given either a normal diet, low NaCl chow (0.04% NaCl), enalapril (0.25 mg/mL in drinking water), or low NaCl + enalapril, for 7 days. Renin mRNA in the hypothalamus was quantified by a competitive reverse transcriptase-polymerase chain reaction (RT-PCR) technique. 3. Renin mRNA concentration in the hypothalamus of rats receiving a normal diet was 52 +/- 3 S.E. fg/microgram total RNA. Low NaCl had no effect (57 +/- 7), whereas values were significantly lower in rats treated with enalapril, either given alone (38 +/- 2; P = 0.002) or combined with a low NaCl diet (33 +/- 4; P = 0.003). 4. In conclusion, we have quantified renin mRNA in the rat hypothalamus and shown that it can be suppressed significantly by enalapril. This response is opposite to that seen in the kidney after enalapril.

Effects of dietary magnesium on blood pressure and vascular lesions in hypertensive rats

The present study examines the effects of dietary magnesium on the development of hypertension and hypertensive vascular lesions in deoxycorticosterone acetate and salt induced (DOCA-salt) and 2 kidney one clip (2K1C) hypertensive as well as normotensive control rats. Animals received a regular (0.12% Mg), high (0.4% Mg) or low (0.03% Mg) magnesium diet for 6 wks. Dietary magnesium did not alter the growth or blood pressure in control, DOCA-salt and 2K1C rats even though the plasma magnesium concentration was significantly altered by the diets (ANOVA, p < 0.05 in control, DOCA-salt and 2K1C, respectively). Dietary magnesium did not alter the urinary potassium excretion, plasma sodium, potassium, total calcium concentration and plasma renin activity in any group, while the high magnesium diet significantly increased the urinary sodium excretion in DOCA-salt (p < 0.05) but not in control and 2K1C rats when compared with the regular magnesium diet. In histological studies, dietary magnesium did not alter the percentage media area of intramyocardial arteries, or glomerular and renal arterial and arteriolar lesions in DOCA-salt and 2K1C rats. This study suggests that moderate alterations of dietary magnesium do not modify blood pressure in normotensive control, DOCA-salt and 2K1C hypertensive rats, nor do they modify vascular disease in these 2 hypertensive models.

The effects of dietary potassium on vascular and glomerular lesions in hypertensive rats

The present study examines the effects of dietary potassium (K) on hypertensive glomerular and vascular lesions in deoxycorticosterone acetate and salt induced (DOCA-salt) and two kidney one clip (2K1C) hypertensive as well as normotensive control rats. Animals received a regular (0.28% K), high (1.1% K) or low (0.07% K) potassium diet for 6 weeks. In control rats, low K diet significantly increased systolic blood pressure (SBP) (p < 0.05). In DOCA-salt rats, high K diet did not modify SBP or glomerular and vascular lesions while low K diet significantly increased premature death in these rats. In 2K1C rats, dietary K did not alter the blood pressure, but percentage media area (% media) of intramyocardial arteries, percentage of glomerular lesions, and renal arterial and arteriolar lesion scores were lower in high K diet rats than regular and low K diet rats (p < 0.05). This study is the first demonstration that high K diet can protect against vascular and glomerular lesions in a non salt-loaded hypertensive model. The beneficial effects of dietary K on vascular lesions are at least in part independent of changes in blood pressure, and may be renin related.

Digoxin amplifies the effects of deoxycorticosterone acetate (DOCA) in intact water-drinking rats: implications for the mechanism of DOCA hypertension?

INTRODUCTION

An increase in digitalis-like substances has been reported in deoxycorticosterone acetate (DOCA)-salt hypertensive rats. We hypothesized that the role of saline and unilateral nephrectomy in DOCA hypertension may be due to stimulation of endogenous digitalis-like substances.

METHODS

We investigated the effects of digoxin and DOCA alone and in combination in intact rats drinking water. Forty male Sprague-Dawley rats were used (body weight 223-298 g).

RESULTS

Neither digoxin (40 micrograms/kg per day, by gavage, for 35 days, n = 10) nor DOCA (30 mg/kg twice a week, subcutaneously, for 5 weeks, n = 10) caused a consistent increase in blood pressure in intact rats drinking water. In contrast, combined digoxin and DOCA administration (n = 10) increased systolic blood pressure from day 18 of treatment onwards, to a maximum at day 34 compared with sham-treated rats (n = 10). There were no consistent changes in water intake, urine volume, urinary sodium or potassium excretion, or plasma sodium or potassium concentration with digoxin treatment. DOCA increased water intake and urine volume, and caused an initial decrease in urinary sodium excretion, but no change in urinary potassium excretion or plasma sodium concentration. Plasma potassium excretion was lower in DOCA- than sham-treated rats.

CONCLUSION

Combined digoxin and DOCA administration in intact rats drinking water increased blood pressure significantly compared with either drug alone, raising the possibility that the mechanism by which nephrectomy and salt loading contribute to DOCA hypertension in the rat might be through stimulation of endogenous digitalis-like substances.

Theory of radiation-induced absorption in optical fibers

A new and simple mathematical model for describing radiation-induced absorption in optical fibers is presented. This model treats the radiation-induced defect generation and the decay process as a series of superposable infinitesimal growth and decay events. Unlike the existing power-law growth equation, the new equation is nonempirical, dose-rate dependent, and describes both the growth and the decay of the induced defect. In the case of constant dose rate the general equation reduces to a simple analytical form that agrees reasonably well with the experiment.

Screening of monoclonal antibodies recognizing oncofetal antigens for isolation of trophoblasts from maternal blood for prenatal diagnosis

Many monoclonal antibodies have been produced against tumour-associated cell surface antigens for cancer therapy. They have therefore been selected for minimal reactivity with normal tissues and in particular for lack of binding to blood cells or serum components. Many of the antigens recognized are of fetal origin. These monoclonal antibodies may therefore be ideal candidates to recognize and sort fetal trophoblasts from maternal blood for prenatal diagnosis of genetic abnormalities. A panel of 19 anti-tumour antibodies were therefore screened for reactivity with early trimester placenta and two, 340 and 154, were shown to stain trophoblasts. If MAb 340 is linked to magnetic beads, it can efficiently sort trophoblast cell lines from whole blood.

Effect of dietary calcium on the development of hypertension and hypertensive vascular lesions in DOCA-salt and two-kidney, one clip hypertensive rats

OBJECTIVE

To examine the effect of modest changes in dietary calcium on systolic blood pressure (SBP) and myocardial and renal vascular lesions in Sprague-Dawley rats.

DESIGN

Regular- (0.4%, by weight), high- (0.8%) or low-calcium (0.24%) diets were fed to normotensive control, deoxycorticosterone acetate (DOCA)-salt and two-kidney, one clip (2-K, 1C) hypertensive rats for 8 weeks.

METHODS

Tail-cuff SBP and metabolic balance were measured once a week. At the end of the study the kidneys and hearts were collected for histological study.

RESULTS

Dietary calcium had no effect on SBP in the DOCA-salt rats, but loading with calcium accelerated the rise in SBP in 2-K,1C rats (P < 0.01, high- versus regular-calcium diet). The high-calcium diet reduced the percentage medial area of intramyocardial arteries in the DOCA-salt and 2-K,1C hypertensive rats. The DOCA-salt rats on the low-calcium diet had a higher renal vascular lesions score than those on the regular- or high-calcium diet (P < 0.05).

CONCLUSIONS

A high-calcium diet appears to prevent intramyocardial vascular wall thickening in DOCA-salt and 2-K,1C hypertensive rats, and a low-calcium diet aggravates renal vascular lesions in DOCA-salt hypertensive rats. These effects are not related simply to changes in blood pressure.

Effect of dietary sodium chloride on the development of renal glomerular and vascular lesions in hypertensive rats

1. The hypothesis that high levels of NaCl in the diet aggravates hypertension-associated renal vascular lesions was examined in unilaterally nephrectomized deoxycorticosterone acetate treated (DOCA) and two kidney one clip (2K1C) hypertensive rats, as well as normotensive controls. 2. High NaCl diet significantly increased systolic blood pressure (SBP) in DOCA rats, but had little effect on SBP in normal control rats, and did not affect the rise of SBP in 2K1C rats. 3. High NaCl diet was associated with a higher percentage of glomerular lesions and renal arterial and arteriolar lesions in DOCA and 2K1C rats (P < 0.05). 4. Thus high NaCl intake exacerbated renal arterial and arteriolar and glomerular lesions in both DOCA and 2K1C hypertensive rats. In 2K1C rats this effect may be in part independent of blood pressure.