A placental model of SARS-CoV-2 infection reveals ACE2-dependent susceptibility and differentiation impairment in syncytiotrophoblasts

SARS-CoV-2 infection causes COVID-19. Several clinical reports have linked COVID-19 during pregnancy to negative birth outcomes and placentitis. However, the pathophysiological mechanisms underpinning SARS-CoV-2 infection during placentation and early pregnancy are not clear. Here, to shed light on this, we used induced trophoblast stem cells to generate an in vitro early placenta infection model. We identified that syncytiotrophoblasts could be infected through angiotensin-converting enzyme 2 (ACE2). Using a co-culture model of vertical transmission, we confirmed the ability of the virus to infect syncytiotrophoblasts through a previous endometrial cell infection. We further demonstrated transcriptional changes in infected syncytiotrophoblasts that led to impairment of cellular processes, reduced secretion of HCG hormone and morphological changes vital for syncytiotrophoblast function. Furthermore, different antibody strategies and antiviral drugs restore these impairments. In summary, we have established a scalable and tractable platform to study early placental cell types and highlighted its use in studying strategies to protect the placenta.

1293 A MULTIDISCIPLINARY TEAM DERIVED QUALITY IMPROVEMENT PROJECT TO IMPROVE THE EFFICIENCY AND EFFECTIVENESS OF THEIR HYBRID MEETING

Introduction

Working in a small district general hospital in Llanelli, West Wales, a weekly hybrid multi-disciplinary team (MDT) meeting is held on the stroke and care of the elderly unit. There are 3 separate geriatric teams covering the ward. Typically, these meetings are attended by physiotherapists, occupational therapists, speech and language therapists, discharge nurses, social workers, nurses and a doctor. The main agenda is to discuss the patients’ current medical issues, rehabilitation needs and likely discharge destination/complexities. Medically, these meetings were attended by a single doctor who often found it difficult to concisely summarise the patient’s medical problems from the notes of patients not under their care. Our aim was to streamline the MDT meeting with regards to quality of content, understanding of patient issues and general efficiency.

Intervention

An initial questionnaire was used to gather prospective data. 90% of MDT members suggested that a doctor from each team should attend to present patients under their care and engage in onward discussions. This was implemented over the period of a month. A follow-up questionnaire collected quantitative data by asking MDT members to retrospectively rate, on a scale of 1 to 10, the efficiency of the meeting and the understanding of patient’s medical conditions before and after implementing the change.

Results

The average efficiency was rated at 4.8/10 before the change was implemented and 8.8/10 afterwards, a 40% improvement. Understanding of patient medical issues had a 28% improvement, from an average rating of 6 to 8.8. Qualitative and free text data was also collected highlighting a secondary benefit of reciprocal communication between the therapy MDT and the appropriate medical doctors hopefully improving the timeliness of any required action.

Conclusions

Suggestions of further changes include making the meeting fully face-to-face, providing a “proforma” to document what was discussed and introducing other members of community teams.

Where have all the appendicectomies gone?

INTRODUCTION

The COVID-19 pandemic stimulated a national lockdown in the UK. The public were advised to avoid unnecessary hospital attendances and health professionals were advised to avoid aerosol-generating procedures wherever possible. The authors hypothesised that these measures would result in a reduction in the number of patients presenting to hospital with acute appendicitis and alter treatment choices.

METHODS

A multicentred, prospective observational study was undertaken during April 2020 to identify adults treated for acute appendicitis. Searches of operative and radiological records were performed to identify patients treated during April 2018 and April 2019 for comparison.

RESULTS

A total of 190 patients were treated for acute appendicitis pre-lockdown compared with 64 patients treated during lockdown. Patients treated during the pandemic were more likely to have a higher American Society of Anesthesiology (ASA) score (p = 0.049) and to have delayed their presentation to hospital (2 versus 3 days, p = 0.03). During the lockdown, the use of computed tomography (CT) increased from 36.3% to 85.9% (p < 0.001), the use of an antibiotic-only approach increased from 6.2% to 40.6% (p < 0.001) and the rate of laparoscopic appendicectomy reduced from 85.3% to 17.2% (p < 0.001). The negative appendicectomy rate decreased from 21.7% to 7.1% during lockdown (p < 0.001).

CONCLUSIONS

The COVID-19 lockdown was associated with a decreased incidence of acute appendicitis and a significant shift in the management approach. The increased use of CT allows the identification of simple appendicitis for conservative treatment and decreases the negative appendicectomy rate.

High burden of viral respiratory co-infections in a cohort of children with suspected pulmonary tuberculosis

Background

The presentation of pulmonary tuberculosis (PTB) in young children is often clinically indistinguishable from other common respiratory illnesses, which are frequently infections of viral aetiology. As little is known about the role of viruses in children with PTB, we investigated the prevalence of respiratory viruses in children with suspected PTB at presentation and follow-up.

Methods

In an observational cohort study, children < 13 years were routinely investigated for suspected PTB in Cape Town, South Africa between December 2015 and September 2017 and followed up for 24 weeks. Nasopharyngeal aspirates (NPAs) were tested for respiratory viruses using multiplex PCR at enrolment, week 4 and 8.

Results

Seventy-three children were enrolled [median age 22.0 months; (interquartile range 10.0–48.0); 56.2% male and 17.8% HIV-infected. Anti-tuberculosis treatment was initiated in 54.8%; of these 50.0% had bacteriologically confirmed TB. At enrolment, ≥1 virus were detected in 95.9% (70/73) children; most commonly human rhinovirus (HRV) (74.0%). HRV was more frequently detected in TB cases (85%) compared to ill controls (60.6%) (p = 0.02). Multiple viruses were detected in 71.2% of all children; 80% of TB cases and 60.6% of ill controls (p = 0.07). At follow-up, ≥1 respiratory virus was detected in 92.2% (47/51) at week 4, and 94.2% (49/52) at week 8.

Conclusions

We found a high prevalence of viral respiratory co-infections in children investigated for PTB, irrespective of final PTB diagnosis, which remained high during follow up. Future work should include investigating the whole respiratory ecosystem in combination with pathogen- specific immune responses.

Timing of HIV diagnosis in children with tuberculosis managed at a referral hospital in Cape Town, South Africa

SETTING

Tygerberg Hospital, Western Cape Province, Cape Town, South Africa.

OBJECTIVE

To investigate the prevalence of and factors associated with simultaneous tuberculosis (TB) and human immunodeficiency virus (HIV) diagnoses in children.

DESIGN

Retrospective cohort study in TB-HIV co-infected children aged <13 years admitted to Tygerberg Hospital in 2012. Data were collected from medical records, laboratory results and electronic TB treatment registers. A simultaneous TB-HIV diagnosis was defined as an HIV diagnosis made within 7 days before or after a diagnosis of TB.

RESULTS

Of 88 children with TB-HIV co-infection, 37 (42%) had a simultaneous TB-HIV diagnosis; 51 children had been known to have HIV before their TB diagnosis. Interruption of antiretroviral therapy (ART) was reported in 9/32 (28%) children with known HIV infection at TB diagnosis, while missed opportunities for ART initiation were identified in 8/19 (42%) ART-naïve children. Simultaneous TB-HIV diagnosis was more likely if maternal HIV infection was unknown at the time of the child's birth (OR 2.7, 95%CI 1.0-7.2), and was associated with unfavourable TB treatment outcomes (OR 5.9, 95%CI 1.4-25.2).

CONCLUSION

TB diagnosis provides an important opportunity to test children for HIV. Missed opportunities for HIV prevention, earlier diagnosis and ART initiation were identified.

Novel application of NIH case definitions in a paediatric tuberculosis contact investigation study

BACKGROUND

International (National Institutes of Health [NIH]) case definitions have been proposed for paediatric tuberculosis (TB) diagnostic studies. The relevance of these definitions for contact tracing studies is unknown.

METHODS

We developed case definitions for a community-based contact tracing diagnostic study. We compare disease certainty using protocol-defined and NIH case definitions and describe TB disease spectrum and severity.

RESULTS

There were 111 potential disease episodes in 109 (21% human immunodeficiency virus [HIV] infected) of 1093 children enrolled. Based on NIH definitions, there were 8 confirmed, 12 probable, 17 possible and 3 unlikely TB and 2 non-TB episodes. Using protocol case definitions, there were 23 episodes of confirmed, 36 probable, 27 possible and 0 unlikely TB and 21 non-TB. Of 111 potential episodes, 69 were unclassifiable using the NIH definition, while 4 were unclassifiable using the protocol definition. Agreement between definitions was 0.30 (95%CI 0.23-0.38). There were 62 episodes (72%) of non-severe and 24 (28%) of severe TB.

CONCLUSIONS

The NIH definition had limited applicability to household contact studies, despite the wide spectrum of disease observed. Further research is needed to develop case definitions relevant to different research settings, including contact investigation to capture the wide spectrum of paediatric TB in clinical research.

Modelling the influence of total suspended solids on E. coli removal in river water

Following sewer overflows, fecal indicator bacteria enter surface waters and may experience different lysis or growth processes. A 1D mathematical model was developed to predict total suspended solids (TSS) and Escherichia coli concentrations based on field measurements in a large-scale flume system simulating a combined sewer overflow. The removal mechanisms of natural inactivation, UV inactivation, and sedimentation were modelled. For the sedimentation process, one, two or three particle size classes were incorporated separately into the model. Moreover, the UV sensitivity coefficient α and natural inactivation coefficient kd were both formulated as functions of TSS concentration. It was observed that the E. coli removal was predicted more accurately by incorporating two particle size classes. However, addition of a third particle size class only improved the model slightly. When α and kd were allowed to vary with the TSS concentration, the model was able to predict E. coli fate and transport at different TSS concentrations accurately and flexibly. A sensitivity analysis revealed that the mechanisms of UV and natural inactivation were more influential at low TSS concentrations, whereas the sedimentation process became more important at elevated TSS concentrations.

25 GENOME EDITING OF SOMATIC CELL NUCLEAR TRANSFER DERIVED ZYGOTES BY CLUSTERED REGULARLY INTERSPACED SHORT PALINDROMIC REPEATS (CRISPR)/Cas9 GUIDE RNA INJECTION

Recent applications of the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system have greatly improved the efficiency of genome editing in pigs. However, in some cases, genetically modified pig models need an additional modification to improve their application. The objective of this experiment was to determine whether a combination of somatic cell NT (SCNT) by using a previously modified donor cell line and subsequent zygote injection with CRISPR/Cas9 guide RNA to target a second gene would result in embryos and offspring successfully containing both modifications. Fibroblast cell lines were collected from fumarylacetoacetate hydrolase deficient (FAH–/–) fetuses and used as the donor cell line. Somatic cell NT was performed by standard technique. A CRISPR guide RNA specific for recombination activating gene 2 (RAG2) was designed and in vitro transcribed from a synthesised gBlock (IDT) containing a T7 promoter sequence, the CRISPR Guide RNA (20 bp), and 85 bp of tracer RNA. The gBlock was PCR amplified with Q5 polymerase (NEB, Ipswich, MA, USA) and in vitro transcribed with the MEGAshortscript™ T7 Transcription Kit (Life Technologies, Grand Island, NY, USA). Guide RNA (20 ng μL–1) and polyadenylated Cas9 (20 ng μL–1, Sigma, St. Louis, MO, USA) were co-injected into the cytoplasm of SCNT zygotes at 14 to 16 h after fusion and activation. Injected SCNT were then cultured in vitro in PZM3 + 1.69 mM arginine medium (MU1) to Day 5. Three embryo transfers were performed surgically into recipient gilts on Day 4 or 5 of oestrus (50, 62, or 70 embryos per pig) to evaluate in vivo development. The remaining embryos were cultured in MU1 to Day 7 and analysed for the presence of modifications to the RAG2 gene. Embryos were classified as modified if they contained an INDEL as measured by both gel electrophoresis and DNA sequencing of PCR amplicons spanning the targeted exon. The RAG2 modification rate was 83.3% (n = 6), of which 50% (n = 3) of the embryos contained biallelic modifications. All control embryos contained a wild-type RAG2 gene (n = 5). Embryo transfer resulted in a 33.3% pregnancy rate (1/3). The combination of SCNT and CRISPR/Cas9 zygote injection can be a highly efficient tool to successfully create pig embryos with an additional modification. This additional technique further improves the usefulness of already created genetically modified pig models. This study was funded by the National Institutes of Health via U42 OD011140.

Persistence of fecal indicator bacteria in sediment of an oligotrophic river: comparing large and lab-scale flume systems

In this study, both a lab and a large-scale flume system were used to investigate the survival of fecal indicator bacteria (FIB) in bed sediments of an alpine oligotrophic river. To determine the influence of substratum on persistence, survival within 3-cm-deep substratum cages versus on thin, biofilm-covered ceramic tiles was tested. Moreover, the impact of bed shear stress on survival in bed sediments was explored. It was seen that in the lab-scale flume having a very low bed shear stress (0.3 N m(-2)), E. coli and enterococci survival in 3-cm-deep substratum cages was nearly the same as in a thin biofilm (200 μm). However, in the large-scale flume system characterized by a bed shear stress of 9 N m(-2), the added protection of the deeper substratum cages promoted considerably longer survival of E. coli and enterococci than the thin biofilm. Additionally, the FIB removal mechanisms in the two flume systems varied. At the lab-scale, enterococci was seen to persist twice as long as E. coli, while in the large-scale flume the two FIB were removed at the same rate. A comparison of qPCR analyses performed in both flumes suggests that bed sediment erosion and the influence of grazers/predators were responsible for FIB removal from the sediments in the large-scale flume, whereas in the lab flume FIB inactivation caused removal. These results indicate that hydraulic parameters such as bed shear stress as well as the presence of macroinvertebrates in a system are both important factors to consider when designing flumes as they can significantly impact FIB persistence in sediments of fast-flowing, alpine streams.

Influence of resuspension on the fate of fecal indicator bacteria in large-scale flumes mimicking an oligotrophic river

In this study, large-scale flume systems simulating an oligotrophic river were used to explore the fate and transport of the fecal indicator bacteria (FIB) Escherichia coli and enterococci following a combined sewer overflow (CSO). Specifically, the removal pattern of FIB from the water column was examined as well as deposition onto the flume bed. Finally, the impact that a sudden increase in bed shear stress has on FIB in the water column was investigated. The large-scale flumes utilized in this study proved extremely useful for our investigations as they very closely approximated conditions within the Isar River (Munich, Germany). By using both natural substratum and fresh river water, as well as a flow velocity of nearly 1 m s(-1) at a water depth of roughly 0.5 m, shear stresses typical of the Isar River (9 N m(-2)) were achieved. As a result, scaling effects were appreciably reduced. In our flume system, UV inactivation played only a minimal role in overall FIB removal. Therefore, we were able to more precisely investigate other mechanisms which result in FIB removal from the water column. From the two standard FIB removal experiments following a CSO, the removal rate coefficient (k) of 0.2 h(-1) was identified for both E. coli and enterococci in the water column. An increase in the bed shear stress led to more than a 150% rise in total suspended solid (TSS) levels in the water column. These elevated TSS levels (≈ 50 mg l(-1)) increased the persistence of suspended FIB in the water column by 20 h (k = 0.05 h(-1)). This indicates that higher TSS loads resulting from resuspended bed sediments can significantly expand the area that is impacted by a CSO event. At lower TSS loads (<20 mg l(-1)) deposition onto the flume bed did not contribute significantly to FIB removal from the water column. Any deposition which did occur did not result in a net accumulation of culturable FIB in the benthic biofilm.

339 BIOENGINEERING OF THE MAMMARY GLAND OF LIVESTOCK: INCREASED PROPEPTIDE PROCESSING OF FACTOR IX IN THE MILK OF TRANSGENIC PIGS BY CO-EXPRESSION OF FURIN

Coagulation Factor IX is a vital protein that plays an important role in the blood coagulation cascade. Hereditary deficiency in the Factor IX gene can result in hemophilia type B, the second most common hemophilia. The milk of transgenic livestock can be an efficient vehicle for producing complex, post-translationally modified blood proteins. The advantages include decreased pathogen risk as well as 100-fold or more production efficiency over blood fractionation and cell culture biotechnology. Although the mammary gland can make many of the complex post-translational modifications necessary for biological function of blood proteins, improvements in propeptide cleavage and decreased proteolytic degradation are desirable. To explore the possibility of producing bioactive human Factor IX protein in pig milk, male and female Landrace fetal fibroblast cells were co-transfected by electroporation with 3 different transgene constructs, Factor IX (FIX), Furin, and SERPINA1. The SERPINA1 construct (containing a Neo selectable marker) was delivered into fetal fibroblasts at a 10-fold-lower molar concentration than the other 2 constructs. Following selection in Geneticin, the presence of all 3 genes was verified by PCR and then cells were used as donors for somatic cell nuclear transfer. Thirteen F0 female piglets from 3 potential different integrations were delivered, and 6 piglets were validated by PCR to be positive for all 3 genes. Among the 6 transgenic pigs, 3 are healthy and able to reach puberty. Milk was collected by induced lactation from 2 gilts. A short murine whey acidic protein promoter-Furin gene was used to limit Furin to the lowest levels needed for pro-FIX processing. Furin was expressed to increase propeptide cleavage efficiency, with the result being complete processing of pro-FIX to FIX at ∼0.3 g L–1 pro-FIX. Total FIX levels were ∼1 g L–1. SERPINA1 was also co-expressed at ∼1 g L–1 or more and this serine protease inhibitor did not seem to inhibit furin processing of the pro-FIX. Fifteen F0 male piglets from 3 potential different integration sites were delivered and all of them were positive for all 3 genes. Four F0 males were chosen to breed with wild-type females, and 5 litters of F1 piglets were born. Of 63 F1 piglets, 22 were tri-transgenic and 3 were di-transgenic (only carrying FIX and Furin). Two F1 females were mated with wild-type males, are confirmed to be pregnant, and will be used to determine the expression level and bioactivity of the Factor IX protein in the milk. Funded by the NIH NCRR (RR018877) and R01 HL078944.

Occurrence and loss over three years of 72 pharmaceuticals and personal care products from biosolids-soil mixtures in outdoor mesocosms

Municipal biosolids are in widespread use as additives to agricultural soils in the United States. Although it is well known that digested sewage sludge is laden with organic wastewater contaminants, the fate and behavior of micropollutants in biosolids-amended agricultural soils remain unclear. An outdoor mesocosm study was conducted in Baltimore, Maryland, to explore the fate of 72 pharmaceuticals and personal care products (PPCPs) over the course of three years in that were placed in plastic containers made from polyvinylchloride and kept exposed to ambient outdoor conditions. Of the 72 PPCPs tested for using EPA Method 1694, 15 were initially detected in the soil/biosolids mixtures at concentrations ranging from low parts-per-billion to parts-per-million levels. The antimicrobials triclocarban and triclosan showed the highest initial concentrations at 2715 and 1265 μg kg(-1), respectively. Compounds showing no discernable loss over three years of monitoring included diphenhydramine, fluoxetine, thiabendazole and triclocarban. The following half-life estimates were obtained for compounds showing first-order loss rates: azithromycin (408-990 d) carbamazepine (462-533 d), ciprofloxacin (1155-3466 d), doxycycline (533-578 d), 4-epitetracycline (630 d), gemfibrozil (224-231 d), norfloxacin (990-1386 d), tetracycline (578 d), and triclosan (182-193 d). Consistent with other outdoor degradation studies, chemical half-lives determined empirically exceeded those reported from laboratory studies or predicted from fate models. Study results suggest that PPCPs shown in the laboratory to be readily biotransformable can persist in soils for extended periods of time when applied in biosolids. This study provides the first experimental data on the persistence in biosolids-amended soils for ciprofloxacin, diphenhydramine, doxycycline, 4-epitetracycline, gemfibrozil, miconazole, norfloxacin, ofloxacin, and thiabendazole.

Effect of alloxan-diabetes on multiple forms of hexokinase in adipose tissue and lung

Comparison has been made of the effect of alloxan-diabetes on the multiple forms of hexokinase (EC 2.7.1.1) in adipose tissue and lung. Types I and II hexokinase were distinguished in adipose tissue by their different stabilities to heat treatment, which made it possible to determine the activity of each form spectrophotometrically; additional confirmatory evidence was obtained from starch-gel electrophoresis. Type II hexokinase was markedly depressed in adipose tissue from alloxan-diabetic rats. Lung contained types I, II and III hexokinase, type I predominating. There was no significant change in the pattern of these multiple forms of hexokinase in lung from alloxan-diabetic rats. These results are discussed in relation to current ideas that the insulin-sensitivity of a tissue may be correlated with the content of type II hexokinase.

Simultaneous nitrification/denitrification in a biofilm airlift suspension (BAS) reactor with biodegradable carrier material

Simultaneous nitrification and denitrification in one reactor has been realized with different methods in the past. The usage of biodegradable biocompounds as biofilm carriers is new. The biocompounds were designed out of two polymers having different degradability. Together with suspended autotrophic biomass the biocompound particles were fluidized in an airlift reactor. Process water from sludge dewatering with a mean ammonium nitrogen concentration of 1150 mg L(-1) was treated in a two stage system which achieved a nitrogen removal of 75%. Batch experiments clearly indicate that nitrification can be localized in the suspended biomass and denitrification in the pore structure of the slowly degraded biocompounds. Images taken with CLSM prove the concept of the pore structure within the biocompounds, which provide both a heterotrophic biofilm and carbon source.

Further thoughts regarding evidence offered in support of the 'Barker hypothesis'

The original objection to the paper by Kwong et al. was that the use of an inappropriate (between-pup) estimate of experimental error had exaggerated the importance of the maternal nutrition effect. From the group's most recent response, it has been possible to regenerate the raw data and carry out a further detailed analysis. It is apparent that despite now using a more sophisticated statistical tool, Kwong et al. have still, in effect, used the between-pup error, thus repeating the previous, probably exaggerated, finding. It is maintained that the nutrition effect should be studied using the between-rat variation, which then provides a result that is a good deal less emphatic. Further, it is felt that there is a very important point of principle involved in this dispute, relating to the rigorous analysis of hierarchical data, particularly in small studies.

Prevalence of sexually transmitted infections and mental health needs of female child and adolescent survivors of rape and sexual assault attending a specialist clinic

OBJECTIVES

To determine the prevalence of sexually transmitted infections (STIs) and the mental health needs of female child and adolescent survivors of rape and sexual assault who were referred to a specialist genitourinary medicine (GUM) clinic.

METHOD

Retrospective case notes review of 98 females aged 16 or less, who attended over a 5 year period (1996-2000).

RESULTS

The overall prevalence of STIs was 26%. Among the girls who were aged 0-12 years (n = 16), one had gonorrhoea and another had Trichomonas vaginalis infection. Prevalence of STIs in those aged 13-16 years, who were not sexually active before the index assault, was 24% and in those who gave a history of previous consensual sexual activity it was 39% (p = 0.17). Chlamydial infection was more common among the girls who disclosed previous consensual sexual activity than in those did not disclose previous sexual activity (p = 0.012). The overall prevalence of vaginal candidiasis was 17% and bacterial vaginosis 13%. More than one third of the study population gave a history of previous sexual, physical, or other abuse. 81% reported having current psychological difficulties. Mood changes and sleep disturbances were reported more frequently than other psychological symptoms; 15% attempted self harm. All types of psychological difficulties, except mood changes, were not affected by the time interval between index assault and first presentation to the clinic and the type of assailant. 29% had no involvement with social and mental health services before their attendance at the clinic

CONCLUSIONS

The prevalence of STIs among female child and adolescent survivors of rape and sexual assault attending a specialist clinic was high. The range of mental health and social difficulties was wide and multiple. The importance of an early assessment for the presence of STIs and mental health difficulties was demonstrated.

Deficiencies of micronutrients, altered bowel function, and quality of life during late follow-up after pancreaticoduodenectomy for malignancy

BACKGROUND/AIM

A previous study in our unit showed an inadequate dietary intake of fat-soluble vitamins and energy after pancreaticoduodenectomy (PD). This study was designed to determine whether deficiencies in dietary intake of micronutrients lead to nutritional deficiencies and to examine the impact of dietary advice on nutrition, bowel function, and quality of life.

METHODS

Ten patients who had undergone PD for malignant disease more than 6 months previously were studied at baseline and follow-up 8 weeks apart. Dietary intakes of energy, fat, and micronutrients were assessed by analysis of weighed food diaries, and serum vitamins and trace elements were measured at each visit. Quality of life questionnaires (EORTC QLQ30 and PAN 26) were answered, and a clinical assessment of the bowel function was made. Targeted dietary intervention was given, where indicated, and its impact on the study parameters was assessed at the second clinic visit.

RESULTS

The patients were generally well nourished. Dietary deficiencies of fat-soluble vitamins were detected (vitamin A, n = 2; vitamin D, n = 10; vitamin E, n = 2), but these correlated with serum deficiency only for vitamin A. The selenium intake was borderline or insufficient in 6 patients' diet, with serum deficiencies in 4. Despite normal intakes of iron and zinc, half the patients showed serum deficiency. The bowel function was an important factor in quality of life, and symptoms improved in 3 patients with enzyme supplements and antidiarrhoeal medication.

CONCLUSIONS

PD patients appear to be prone to a predictable set of micronutrient deficiencies that may be compounded by insufficient dietary intake. The bowel function is important to these patients, and it should be optimized with aggressive enzyme replacement. Dietary intervention appears to make little short-term impact in the areas studied.

Fatty acid abnormalities in chronic pancreatitis: effect of concomitant diabetes mellitus

OBJECTIVE

Patients with chronic pancreatitis suffer from malabsorption and nutritional deficiencies. However there is little data available concerning the fatty acid profile in chronic pancreatitis. Diabetes mellitus, a common complication of this disease, could interfere with the metabolism of fatty acids.

SUBJECTS

We therefore compared the fatty acid composition of LDL from four groups of male patients with (a) chronic pancreatitis without diabetes (ND-CP; n=12), (b) diabetes secondary to chronic pancreatitis and insulin-treated (CP-D; n=35); (c) type 1 diabetes (n=25); and (d) controls (n=20).

RESULTS

The patients in both groups of chronic pancreatitis (ND-CP and CP-D) had lower mean values for linoleic acid than that seen in the type 1 DM and control groups, whereas monounsaturated fatty acids (MUFA; 18 : 1(n-9) and (16 : 1(n-7)) were significantly increased in these two groups (ND-CP and CP-D). Docosa-hexaenoic-acid (22 : 6(n-3)) was significantly decreased in the CP-D group (P>0.05), a response that could be explained by the effects of diabetes mellitus and by selenium deficiency. In this way, diabetes was associated with a decrease in the docosa-hexaenoic-acid (22 : 6(n-3); r=0.30, P=0.005), and selenium was correlated with DHA (r=0.28, P=0.029) and with the 22 : 6(n-3)/20 : 5(n-3) ratio (evaluating the delta 4 desaturation); r=0.31, P=0.022), independently of the diabetes effect. Selenium was negatively correlated with 20 : 4(n-6)/20 : 3(n-6) ratio (evaluating the delta 5 desaturase; r=-0.30; P=0.025). These results suggest that these two factors may have a role in the regulation of the desaturation process. If we consider that a ratio of 16 : 1(n-7)/18 : 2(n-6) greater than 0.086 in plasma indicates an EFAn-6 deficiency, 40% of our CP patients, 57.6% of CP-D patients and 13.6% of type 1 DM patients were involved.

CONCLUSIONS

The consequences of these deficiencies are not evaluated in this disease. However, correction of the fundamental deficiencies in essential fatty acids and in selenium seems desirable in chronic pancreatitis.

Microfluidic technology for assisted reproduction

The physical tools used in assisted reproduction have changed little over several decades. Microfluidics is an emerging technology that allows a fresh examination of the way assisted reproduction is performed. Here we review our work to develop microfluidic devices to perform the functions required in assisted reproduction. These functions include loading/unloading, culture, chemical manipulation, and mechanical manipulation of embryos and oocytes. Basic microfluidic theory and microfluidic device design and operation are discussed. Results are presented for mechanical removal of cumulus cells and for embryo culture. Results suggest that microfluidic systems will lead to improved efficiencies in assisted reproduction.

Potential dangers in the customary methods of conducting meta-analyses. Recombinant versus urinary follicle stimulating hormone

The customary method of combining success rates in meta-analyses may often result in serious biases, leading to erroneous inferences. This arises because of an inadmissible pooling of frequencies from heterogeneous sources. The fundamental statistical principle, that the magnitude of an 'effect' should always be tested against the variation in that effect over the sample, may not therefore be satisfied. A simple, but rigorous, alternative method is described.

Effect of the inflammation, chronic hyperglycemia, or malabsorption on the apolipoprotein A-IV concentration in type 1 diabetes mellitus and in diabetes secondary to chronic pancreatitis

The metabolism of apolipoprotein (apo) A-IV in diabetes mellitus (DM) is poorly understood. Several factors, such as dietary fat intake, fat malabsorption, acute inflammation, and hormonal dysregulation can disturb the plasma apo A-IV concentration. We have compared the plasma apo A-IV concentrations in patients with type 1 DM and DM secondary to chronic pancreatitis to determine the effects of combinations of these factors. We examined 4 groups of male patients with chronic pancreatitis without diabetes (ND-CP) (n = 12), diabetes secondary to chronic pancreatitis and insulin-treated (CP-DM) (n = 32), type 1 diabetes (n = 25), and controls (n = 20). Plasma apo A-IV was significantly lower in the chronic pancreatitis patients (ND-CP and CP-DM) than in the other patients. Inflammatory proteins (fibrinogen, ceruloplasmin, and haptoglobin) were significantly elevated in the 2 chronic pancreatitis groups. The apo A-IV concentration was positively correlated with hemoglobin A(1c) (HbA(1c)) percentage in each group of diabetic patients (CP-DM, r =.35; P =.046; type 1 DM, r =.53; P =.010), in both groups of diabetic patients (r =.472; P <.0001) and negatively correlated with ceruloplasmin concentration in each group of diabetic patients (CP-DM, r = -.48; P =.0052; type 1 DM, r = -.66; P =.003), in both groups of diabetic patients (r = -.561; P <.0001), and in the whole population (r = -.463; P <.0001). Apo A-IV was also negatively correlated with haptoglobin in type 1 DM patients (r = -.434; P =.0435), in the both groups of diabetic patients (r = -.349; P =.0154), and in the whole population (r = -.351; P =.0019). Multiple linear regression analysis revealed that only HbA(1c) and ceruloplasmin were independent explanatory variables. Plasma apo A-IV is positively correlated with HbA(1c) suggesting that hyperglycemia per se selectively affects apo A-IV metabolism. The correlation between the concentrations of inflammatory protein and apo A-IV suggest a link between chronic inflammation and apo A-IV synthesis or catabolism. As apo A-IV is involved in reverse cholesterol transport, its low level in CP-DM may contribute to the accelerated development of atherosclerosis in these patients.

The OMP-lacZ transgene mimics the unusual expression pattern of OR-Z6, a new odorant receptor gene on mouse chromosome 6: implication for locus-dependent gene expression

Reporter gene expression in the olfactory epithelium of H-lacZ6 transgenic mice mimics the cell-selective expression pattern known for some odorant receptor genes. The transgene construct in these mice consists of the lacZ coding region, driven by the proximal olfactory marker protein (OMP) gene promoter, and shows expression in a zonally confined subpopulation of olfactory neurons. To address mechanisms underlying the odorant receptor-like expression pattern of the lacZ construct, we analyzed the transgene-flanking region and identified OR-Z6, the first cloned odorant receptor gene that maps to mouse chromosome 6. OR-Z6 bears the highest sequence similarity (85%) to a human odorant receptor gene at the syntenic location on human chromosome 7. We analyzed the expression pattern of OR-Z6 in olfactory tissues of H-lacZ6 mice and show that it bears strong similarities to that mapped for beta-galactosidase. Expression of both genes in olfactory neurons is primarily restricted to the same medial subregion of the olfactory epithelium. Axons from both neuronal subpopulations project to the same ventromedial aspect of the anterior olfactory bulbs. Furthermore, colocalization analyses in H-lacZ6 mice demonstrate that OR-Z6-reactive glomeruli receive axonal input from lacZ-positive neurons as well. These results suggest that the expression of both genes is coordinated and that transgene expression in H-lacZ6 mice is regulated by locus-dependent mechanisms.

Does olfactory marker protein participate in olfactory neurogenesis?

Olfactory marker protein (OMP) is a phylogenetically conserved, 19-kDa, acidic, soluble protein found abundantly in mature olfactory sensory neurons. Its function has been enigmatic although recent evidence from studies on OMP null mice suggests that neurons lacking OMP exhibit altered physiological activity, including prolonged onset and recovery kinetics following stimulation. We have reported increased expression of OMP in individual surviving sensory neurons that have been deprived of their target, the olfactory bulb. Because olfactory epithelia deprived of their target also exhibit an increased rate of cell division we investigated the effect of recombinant OMP on cell division in organotypic cultures of fetal rat (embryonic day 19) epithelium grown for 3 days in vitro. After 3 days, cultures were given a 1-hr pulse of a mitotic marker, bromodeoxyuridine (BrdU), fixed and prepared for immunohistochemistry to determine the number of proliferating cells. We found a dose-dependent increase in the number of BrdU-positive cells/100-mm length of epithelium. The number of labeled cells increased incrementally, reached a plateau at 25 pM OMP/ml culture medium, 50% higher than in cultures with no OMP added, and remained at that level at 50 and 100 pM doses. Controls included trypsinized OMP and addition of equivalent volumes of TRIS buffer lacking OMP. These results, taken together with previous studies on several growth factors indicate that regulation of neurogenesis in olfactory tissue is a multifactorial process and that OMP may play a role.

Effects of mutation of the Olf-1 motif on transgene expression in olfactory receptor neurons

We have examined the effect of mutating the Olf-1 binding motif of the olfactory marker protein (OMP) promoter in determining olfactory neuron-specific gene expression in adult tissues and during embryonic development. The proximal Olf-1 motif located 170 nucleotides upstream of the transcription start site of the OMP gene was mutated to prevent its interaction with the Olf-1 factor in vitro. The wild-type and mutated fragments of the OMP gene extending from -239 to +55 nucleotides relative to the transcription start site were used to direct expression of a lacZ reporter gene in transgenic mice. The transgenic animals were analyzed for cell-specific and developmental expression of the reporter gene. We demonstrate that the mutation that prevents interaction of Olf-1 with its binding site does not alter the temporal and spatial patterns of gene expression in olfactory sensory neurons but does alter the specificity and level of expression in other neuronal populations. These observations are consistent with our demonstration that the mutated Olf-1 site interacts with nuclear proteins present in the central nervous system (CNS).

An enhanced olfactory marker protein immunoreactivity in individual olfactory receptor neurons following olfactory bulbectomy may be related to increased neurogenesis

Olfactory marker protein (OMP) is a 19-kD acidic protein found throughout the cytoplasm of mature olfactory receptor neurons (ORNs). Its function remains unknown. Following olfactory bulbectomy, the proportion of ORNs mature enough to express OMP declines greatly. However, in the few remaining mature ORNs, it has been observed that the intensity of OMP immunoreactivity (IR) appears to increase over that of ORNs on the unoperated side. We have now investigated this phenomenon quantitatively in rats subjected to unilateral olfactory bulbectomy. Results show that at all postbulbectomy survival periods examined quantitatively (3 days to 6 months), a significant decrease (19-37%) occurs in the transmission of incident light through OMP(+)-ORNs in bulbectomized versus unoperated olfactory epithelium (OE). Further, we also observed a consistent side-to-side difference in OMP IR in control unoperated animals. Possible explanations for these observations and their relation to the still unknown function of OMP are discussed. To test the possibility that OMP might serve a mitogenic role in the OE, recombinant OMP was added to organotypic explant cultures of fetal olfactory mucosa. Addition of OMP resulted in a dose-dependent increase in the density of bromodeoxyuridine-positive cells in the cultures, with a 50% increase occurring at the plateau OMP concentration of 25 pM.

Prenatal differentiation of mouse vomeronasal neurones

The vomeronasal organ (VNO) subserves basic chemosensory functions in rodents, mainly related to sexual behaviour. In order to understand early stages of the VNO structural maturation, we have undertaken an immunocytochemical analysis of the VNO of fetal mice. Our results demonstrate that Olfactory Marker Protein (OMP), a marker of differentiated chemosensory cells, is already expressed in vomeronasal neurones and their fibres projecting to the accessory olfactory bulb during the last week of gestation. However, in contrast to the adult, where its expression is restricted to the medial sensory neuronal component of the VNO, during fetal development OMP is also present in cells located in the lateral non-sensory epithelial component. Some other markers of nasal chemosensory neurones, such as GAP-43/B-50, Protein Gene Product 9.5 (PGP 9.5) and carnosine are also transiently expressed in this ectopic site. These results indicate that (i) significant morphological and biochemical maturation of the VNO is achieved before birth; (ii) transient cell populations, sharing the biochemical profile of the vomeronasal chemosensory receptors, occur in ectopic areas during fetal development.

LacZ and OMP are co-expressed during ontogeny and regeneration in olfactory receptor neurons of OMP promoter-lacZ transgenic mice

The ontogeny and cellular specificity of expression of beta-galactosidase activity and olfactory marker protein (OMP) are compared in olfactory tissue of the H-OMP-lacZ-3 line of transgenic mice. In this line the expression of lacZ is driven by a 0.3 kb fragment of the rat OMP promoter. During fetal development, lacZ expression is detectable in olfactory receptor neurons (ORNs) shortly after the initial appearance of endogenous OMP. The beta-galactosidase marker was observed only in mature olfactory receptor neurons where it co-localized with endogenous OMP. It was absent from immature neurons that express the growth associated phosphoprotein B50/GAP43. Lesion of the peripheral olfactory pathway by intranasal irrigation with Triton X-100 eliminated expression of both OMP and lacZ in the olfactory neuroepithelium. Subsequent regeneration of the full complement of olfactory receptor neurons was associated with co-expression of both OMP and beta-galactosidase activity. Neither OMP nor beta-galactosidase activity was induced in any other cell type of the regenerating olfactory mucosa. Thus, as little as 0.3 kb of the OMP promoter has the ability to target lacZ expression to olfactory receptor neurons in a temporally and spatially defined manner. We discuss the potential utility of this transgenic line for future studies of the olfactory system.

Olfactory glomeruli are innervated by more than one distinct subset of primary sensory olfactory neurons in mice

The rodent olfactory epithelium consists of a mosaic of primary sensory olfactory neurons (PONs) which express distinct putative olfactory receptor proteins. Recent evidence suggests that individual subsets of these sensory neurons project to separate glomeruli in the olfactory bulb (Vassar et al., [1994] Cell 79:981-991). In the present study we have identified two distinct subsets of primary sensory olfactory neurons (PONs) in the H-OMP-LacZ-6 transgenic mouse. In these transgenic mice, a LacZ reporter gene under the control of a 294 base pair element from the 5' promoter region of the olfactory marker protein (OMP) gene was expressed in a subset of PONs located in a discrete band of neuroepithelium in the nasal cavity. These LacZ positive neurons were not randomly located within this band but were more concentrated within a locus between endoturbinates IIb and III. The axons of these neurons densely innervated three adjacent and bilaterally symmetrical glomeruli present in the ventromedial olfactory bulb. Labeling of tissue sections with the plant lectin Dolichos biflorus (DBA) revealed an independent subset of PONs in the transgenic mice. These neurons were present in a wide region of the nasal cavity that included the neuroepithelial band containing the LacZ expressing neurons. The DBA labeled axons terminated in glomeruli in the rostromedial and dorsolateral olfactory bulb surfaces. Although the glomeruli innervated by the LacZ and DBA positive axons were predominantly non-overlapping there were glomeruli in the ventral olfactory bulb that were labeled by both DBA and LacZ markers. Eight different types of glomeruli were characterized. Most notably, glomeruli were identified which were innervated partially by both or by either subset alone. In these cases, axon subsets were observed to terminate within discrete subregions of a glomerulus. These results support the hypothesis that phenotypically distinct subsets of PONs converge on to the same glomeruli but also indicate that some glomeruli are innervated by more than one subset of sensory neuron. These findings have implications for understanding how the olfactory projection is formed and how olfactory information is processed.

Proximal regions of the olfactory marker protein gene promoter direct olfactory neuron-specific expression in transgenic mice

Olfactory marker protein (OMP) expression is highly restricted to mature olfactory neurons (ON). Less than 0.3 kb of upstream 5' flanking sequence of the OMP gene directs lacZ expression preferentially to ON in several independently derived lines of transgenic mice. A larger transgene with 0.8 kb of upstream flanking sequence also gave lacZ expression in ON and in a few ectopic sites in the central nervous system (CNS). In addition to the main olfactory epithelium, endogenous OMP is also expressed in chemosensory neurons of the vomeronasal and septal organs, and lacZ expression was detected in neurons of these sites as well. This confirmed the presence of regulatory sequences in the proximal portion of the OMP gene. Endogenous OMP expression in ON was normal in all transgenic lines. Strikingly, in several transgenic lines lacZ expression was restricted to subsets of ON. In one such line, ON axons were intensely stained for lacZ and projected to a subset of olfactory bulb glomeruli. Although identifiable subsets of ON and their termination fields have been described previously, this is the first demonstration of this phenomenon in transgenic mice. These lines of transgenic mice thus provide in vivo models for characterization of genetic elements regulating developmental and functional organization of the olfactory neuroepithelium.