Strongyloides stercoralis hyperinfection presenting pneumatosis intestinalis and acute respiratory distress syndrome after treatment for COVID-19.

A 91-year-old man was admitted with vomiting and abdominal pain. He had had COVID-19 pneumonia a month before and the treatment had consisted of remdesivir, dexamethasone and baricitinib. CT scans showed pneumatosis intestinalis. His respiratory condition rapidly deteriorated and chest CT scans showed ground-glass opacity and Strongyloides stercoralis was identified in the sputum, making a diagnosis of hyperinfection syndrome associated acute respiratory distress syndrome. Treatment of ivermectin was not achieved in time and he died of multiple organ failure. S. stercoralis is a soil-transmitted helminth endemic to tropical and subtropical areas. Immunosuppressive conditions can cause hyperinfection syndrome and life-threatening conditions. Our case highlights the importance of assessing for untreated chronic strongyloidiasis in COVID-19 patients requiring steroid treatment in endemic areas.

[Companion Diagnostics for Thrombotic Disease].

In recent years, thrombotic disease, including myocardial infarction and ischemic stroke, has rapidly increased in Japan. To treat and prevent thromboembolism, warfarin has been commonly prescribed for a long period as an oral anticoagulant. However, it is difficult to define an appropriate warfarin dose because of large inter-individual variability in dose requirements and the narrow therapeutic range. Recent pharmacogenomic (PGx) studies have shown that several single nucleotide polymorphisms (SNPs) in CYP2C9 (warfarin metabolic enzyme) and VKORC1 (warfarin target enzyme) are responsible for an individual's warfarin sensitivity. In order to realize personalized warfarin treatment, algorithms to estimate the required warfarin dose based on PGx are under consideration, including the cost-effectiveness. Recently, novel oral anticoagulants (NOACs; dabigatran, rivaroxaban, apixaban, and edoxaban) have become available as well as alternatives to warfarin treatment for the prevention of ischemic stroke in non-valvular atrial fibrillation. Although NOACs are prescribed at a fixed-dose without frequent monitoring of blood coagulability, it has been reported that there is inter-individual variability in the blood concentration of dabigatran caused by gene polymorphisms. Further studies are needed to perform more effective and safer anticoagulant therapy using NOACs. Progress in PGx studies and the realization of personalized anticoagulant therapy are expected in the future. [Review].

[Monitoring of Oral Thrombin Inhibitor].

Dabigatran etexilate is a prodrug that is converted into its active metabolite, dabigatran, by hydrolysis. Dabigatran is a selective thrombin inhibitor that has been approved for the prevention of stroke in patients with non-valvular atrial fibrillation in Japan. Laboratory monitoring is not needed, but an assessment of its anticoagulant effect in certain clinical settings, such as emergency surgery, suspected overdose, or the occurrence of bleeding, is desirable. We overview the special coagulation assays, such as Hemoclot Thrombin Inhibitor (HTI), the thrombin generation assay (TGA), ecarin clotting time (ECT), ecarin chromogenic assay (ECA), prothrombinase-induced clotting time (PiCT), and activated clotting time (ACT). We also examined the relationship between dabigatran levels as determined by HTI, and the activated partial thromboplastin time (APTT) and prothrombin time (PT). APTT and PT demonstrated a positive correlation with the dabigatran levels. APTT, PT, and the combination of APTT and PT may estimate the dabigatran levels in plasma.

Development of a highly sensitive three-dimensional gel electrophoresis method for characterization of monoclonal protein heterogeneity.

Three-dimensional gel electrophoresis (3-DE), which combines agarose gel electrophoresis and isoelectric focusing/SDS-PAGE, was developed to characterize monoclonal proteins (M-proteins). However, the original 3-DE method has not been optimized and its specificity has not been demonstrated. The main goal of this study was to optimize the 3-DE procedure and then compare it with 2-DE. We developed a highly sensitive 3-DE method in which M-proteins are extracted from a first-dimension agarose gel, by diffusing into 150 mM NaCl, and the recovery of M-proteins was 90.6%. To validate the utility of the highly sensitive 3-DE, we compared it with the original 3-DE method. We found that highly sensitive 3-DE provided for greater M-protein recovery and was more effective in terms of detecting spots on SDS-PAGE gels than the original 3-DE. Moreover, highly sensitive 3-DE separates residual normal IgG from M-proteins, which could not be done by 2-DE. Applying the highly sensitive 3-DE to clinical samples, we found that the characteristics of M-proteins vary tremendously between individuals. We believe that our highly sensitive 3-DE method described here will prove useful in further studies of the heterogeneity of M-proteins.

BDNF, produced by a TPO-stimulated megakaryocytic cell line, regulates autocrine proliferation.

While human platelets release endogenous brain-derived neurotrophic factor (BDNF) upon activation, a previous report on MEG-01, a megakaryocytic cell line, found no trace of BDNF production, and the pathophysiological function of platelet BDNF has remained elusive. In the present study, we demonstrate that MEG-01 produces BDNF in the presence of TPO and that this serves to potentiate cell proliferation. Our in vitro findings suggest that BDNF regulates MEG-01 proliferation in an autocrine manner, and we suggest that BDNF may be a physiological autocrine regulator of megakaryocyte progenitors.

Effects of molecular structural variants on serum Krebs von den Lungen-6 levels in sarcoidosis.

BACKGROUND: Serum Krebs von den Lungen-6 (KL-6), which is classified as human mucin-1 (MUC1), is used as a marker of sarcoidosis and other interstitial lung diseases. However, there remain some limitations due to a lack of information on the factors contributing to increased levels of serum KL-6. This study was designed to investigate the factors contributing to increased levels of serum KL-6 by molecular analysis. METHODS: Western blot analysis using anti-KL-6 antibody was performed simultaneously on the bronchoalveolar lavage fluid (BALF) and serum obtained from 128 subjects with sarcoidosis. RESULTS: KL-6/MUC1 in BALF showed three bands and five band patterns. These band patterns were associated with the MUC1 genotype and the KL-6 levels. KL-6/MUC1 band patterns in serum were dependent on molecular size class in BALF. Significantly increased levels of serum KL-6, serum/BALF KL-6 ratio and serum soluble interleukin 2 receptor were observed in the subjects with influx of high molecular size KL-6/MUC1 from the alveoli to blood circulation. The multivariate linear regression analysis involving potentially relevant variables such as age, gender, smoking status, lung parenchymal involvement based on radiographical stage and molecular size of KL-6/MUC1 in serum showed that the molecular size of KL-6/MUC1 in serum was significant independent determinant of serum KL-6 levels. CONCLUSIONS: The molecular structural variants of KL-6/MUC1 and its leakage behavior affect serum levels of KL-6 in sarcoidosis. This information may assist in the interpretation of serum KL-6 levels in sarcoidosis.

Impact of asthmatic control status on serum cystatin C concentrations.

BACKGROUND: To determine whether cystatin C accurately reflects renal function in asthma, we investigated serum cystatin C concentrations in a large number of asthmatic patients by adjusting for several confounding factors that might affect serum cystatin C concentrations. METHODS: A total of 126 asthmatic patients and 126 healthy volunteers, matched for age and gender, were studied. RESULTS: Serum cystatin C concentrations in symptomatic subjects with asthma were significantly higher than in healthy controls (p < 0.001) and asymptomatic subjects with asthma (p = 0.007), whereas no significant difference was observed between healthy controls and asymptomatic subjects. In asthmatic subjects, serum cystatin C concentrations were not influenced by inhaled corticosteroid (ICS). However, serum cystatin C concentrations were significantly higher in subjects who were regularly treated by oral corticosteroid (OCS) (p = 0.001). CONCLUSIONS: Serum cystatin C concentrations are elevated in asthmatic patients; particularly while symptomatic and/or taking OCS but not ICS. Serum cystatin C concentrations may not accurately reflect renal function in those patients.

Total serum IgE levels and atopic status in patients with sarcoidosis.

To date, two studies have reported lower total serum immunoglobulin E (IgE) levels and lower prevalence of atopy in patients with sarcoidosis compared with healthy subjects. However, those reports did not consider age or gender differences between cases and controls. In addition, the association between total serum IgE levels and clinical manifestations of sarcoidosis has not been clarified. This study assessed total serum IgE levels and prevalence of atopy in patients with sarcoidosis after taking age and sex differences into account and evaluated associations between total serum IgE levels and clinical manifestations of sarcoidosis. Total serum IgE levels and prevalence of atopy on initial visits were compared between 189 patients with sarcoidosis and 378 age- and sex-matched controls. Associations between total serum IgE levels and involvement of each affected organ were evaluated. Changes in total serum IgE levels during the clinical course of sarcoidosis were also evaluated. Total serum IgE levels were significantly lower in patients with sarcoidosis than in controls, independent of atopic status (atopic subjects, p = 0.025; nonatopic subjects, p < 0.001). Total serum IgE levels did not differ according to the involvement of different organs. Total serum IgE levels decreased further, albeit only slightly, after disease remission (p < 0.001). Increased susceptibility to sarcoidosis may be attributable to several underlying genetic or environmental factors that result in lower total serum IgE levels.

Ciliates promote the transfer of the gene encoding the extended-spectrum ß-lactamase CTX-M-27 between Escherichia coli strains.

OBJECTIVES: The mechanism by which Escherichia coli acquires multidrug resistance genes from other bacteria in the natural environment or livestock is still unclear. The ability of ciliates to promote the transfer of genes encoding extended-spectrum ß-lactamases (ESBLs) between the CTX-M-27 donor and clinically isolated recipient E. coli strains was investigated. METHODS: Equal amounts (∼10(9) cfu) of donor cefotaxime-resistant E. coli and recipient ciprofloxacin-resistant E. coli strains were mixed together in the presence or absence of 10(5) ciliates in Page's amoeba saline for 24 h, in the presence or absence of certain drugs (cytochalasin D, cycloheximide and latrunculin B). RESULTS: Gene transfer frequency in the presence of ciliates was estimated at ∼10(-6); in the absence of ciliates it was ∼10(-10). Protein synthesis (cycloheximide) or phagocytosis (cytochalasin D or latrunculin B) inhibitors significantly reduced the frequency of gene transfer. CONCLUSIONS: Ciliates promote the transfer of genes encoding ESBLs between E. coli strains, implying that the presence of ciliates may provide a significant impact on emerging multidrug-resistant bacteria.

Chlamydophila pneumoniae attachment and infection in low proteoglycan expressing human lymphoid Jurkat cells.

This study investigated the proteoglycan (PG)-dependent mechanism of Chlamydophila pneumoniae attachment to lymphocytic cells. Lymphoid Jurkat cells and epithelial HEp-2 cells were statically infected with C. pneumoniae (TW183). Transmission electron microscopy and assessment of inclusion-forming units indicated that the bacteria grew normally in Jurkat cells and were capable of producing secondary infection; however, they grew at a slower rate than in HEp-2 cells. RT-PCR analysis indicated that HEp-2 cells strongly expressed PG-core protein encoding genes, thereby sustaining glycosaminoglycans (GAGs), such as heparin, on the cellular surface. Similar gene expression levels were not observed in Jurkat cells, with the exception of glypican-1. Immunofluorescence analysis also supported strong heparin expression in HEp-2 cells and minimal expression in Jurkat cells, although heparan sulfate pretreatment significantly inhibited bacterial attachment to both cell types. Immunofluorescent co-staining with antibodies against chlamydial LPS and heparin did not identify bacterial and heparin co-localization on Jurkat cells. We also confirmed that when C. pneumoniae was statically infected to human CD4(+) peripheral blood lymphocytes known not expressing detectable level of heparin, the bacteria attached to and formed inclusion bodies in the cells. Thus, the attachment mechanism of C. pneumoniae to Jurkat cells with low PG expression is unique when compared with HEp-2 cells and potentially independent of GAGs such as heparin.

Early diastolic mitral annular velocity at the interventricular septal annulus correctly reflects left ventricular longitudinal myocardial relaxation.

AIMS: Early diastolic mitral annular velocity (e') obtained by tissue Doppler imaging (TDI) is widely used to evaluate left ventricular (LV) diastolic function based on the assumption that it reflects myocardial relaxation in the long-axis direction. In this study, we aimed to determine whether or not e' truly reflects early diastolic longitudinal myocardial relaxation, and which is the most useful for evaluating LV diastolic function among e' measured at the interventricular-septal annulus (IS-e'), that measured at the lateral annulus (LW-e') or their mean value (M-e'). METHODS AND RESULTS: IS-e', LW-e', and M-e' were measured using colour TDI in 15 patients with hypertrophic cardiomyopathy, 13 patients with hypertension, and 19 control subjects. Using two-dimensional speckle-tracking imaging, early diastolic myocardial strain rates (SR(E)) were measured for the IS (IS-SR(E)), LW (LW-SR(E)), and entire LV myocardium (G-SR(E)). IS-e' was excellently correlated with IS-SR(E) (r = 0.90, P < 0.001); the correlation was better than that between LW-e' and LW-SR(E) (r = 0.75, P < 0.001). IS-e' and M-e' were well correlated with G-SR(E) (r = 0.88, P < 0.001 and r = 0.86, P< 0.001, respectively) and with LV early diastolic flow propagation velocity (FPV) (r = 0.77, P < 0.001 and r = 0.78, P < 0.001, respectively). The correlations of LW-e' to G-SR(E) (r = 0.80, P < 0.001) and FPV (r = 0.75, P < 0.001) did not reach this level. CONCLUSION: IS-e' well reflected LV longitudinal myocardial relaxation and LV diastolic function, and was found to be more useful in evaluating LV diastolic function than LW-e'.

Impact of free-living amoebae on presence of Parachlamydia acanthamoebae in the hospital environment and its survival in vitro without requirement for amoebae.

Parachlamydia acanthamoebae is an obligately intracellular bacterium that infects free-living amoebae and is a potential human pathogen in hospital-acquired pneumonia. We examined whether the presence of P. acanthamoebae is related to the presence of Acanthamoeba in an actual hospital environment and assessed the in vitro survival of P. acanthamoebae. Ninety smear samples were collected between November 2007 and March 2008 (trial 1, n = 52) and between October 2008 and February 2009 (trial 2, n = 38) from the floor (dry conditions, n = 56) and sink outlets (moist conditions, n = 34) of a hospital. The prevalences of P. acanthamoebae DNA in the first and second trials were 64.3% and 76%, respectively. The prevalences of Acanthamoeba DNA in the first and second trials were 48% and 63.1%, respectively. A statistical correlation between the prevalence of P. acanthamoebae and that of Acanthamoeba was found (trial 1, P = 0.011; trial 2, P = 0.022), and that correlation increased when samples from just the dry area (floor smear samples, P = 0.002) were analyzed but decreased when samples from a moist area were analyzed (P = 0.273). The in vitro experiment showed that, without Acanthamoeba, P. acanthamoebae could not survive in dry conditions for 3 days at 30 degrees C or 15 days at 15 degrees C. Thus, both organisms were coincidentally found in an actual hospital environment, with the presence of Acanthamoeba having a significant effect on the long-term survival of P. acanthamoebae, suggesting that this potential human pathogen could spread through a hospital environment via Acanthamoeba.

Levels of transferrin in bronchoalveolar lavage fluid in sarcoidosis.

There has been only one report showing high levels of transferrin (Tf) in bronchoalveolar lavage fluid (BALF) in patients with sarcoidosis. This study was designed to assess the levels of Tf in both BALF and serum and to examine the relationship between the levels of Tf and other disease markers in sarcoidosis. Subjects were 64 sarcoidosis and 10 healthy controls. Tf in BALF and serum was measured by nephelometric assay. Median Tf levels in BALF from sarcoidosis was 0.70 (range, 0.00-3.97) mg/dl, which was significantly higher compared with controls (0.36 (range, 0.00-1.02) mg/dl; p = 0.005). In contrast, median Tf levels in serum from sarcoidosis was 258 (range, 171- 383) mg/dl, which was significantly lower compared with controls (322 (range, 234-356) mg/dl; p = 0.003). Tf levels in BALF were significantly correlated with both the percentage of lymphocytes (r = 0.617, p = 0.001) and serum angiotensin-converting enzyme activity (r = 0.363, p = 0.003) and serum soluble interleukin-2 receptor (r = 0.450, p = 0.001) in sarcoidosis. Levels of Tf in BALF from patients with sarcoidosis were not influenced by smoking status. The levels of Tf in sarcoidosis are high in BALF, but low in serum. Increased levels of Tf in BALF may reflect the disease activity.

Mutation analysis of the SDHB and SDHD genes in pheochromocytomas and paragangliomas: identification of a novel nonsense mutation (Q168X) in the SDHB gene.

Pheochromocytoma (PCC) and paraganglioma (PGL) are tumors of the autonomic nervous system. The former is a tumor that occurs in only adrenal glands, and the latter can be found in the head and neck or in the thorax and abdomen. In PCC and PGL, genetic mutations account for approximately 30% of functional (secrete catecholamines) and nonfunctional cases. In addition to RET, VHL and NF-1, genes encoding succinate dehydrogenase complex subunit B (SDHB), subunit C (SDHC), and subunit D (SDHD) are recognized as susceptibility genes for PCC and PGL. Recently, PCC and PGL caused by genetic mutations of SDHB, SDHC and SDHD were established as hereditary pheochromocytoma paraganglioma syndrome (HPPS). Approximately 15% of all PCCs and PGLs are recognized as HPPS. Among these three susceptibility genes, SDHB and SDHD are known to be strongly related to HPPS. The aim of this study was to analyze SDHB and SDHD mutations in PCC and PGL patients. Among 18 patients, we identified a novel heterozygous nonsense mutation at codon 168 resulting in a CAG (glutamine) to TAG (stop) substitution (Q168X) in the SDHB gene in a patient diagnosed with solitary sporadic PGL. A number of studies have reported that SDHB mutation-associated disease demonstrates a higher rate of malignancy. However, all seven patients diagnosed with malignancy in this study did not have genetic mutation of SDHB and only one patient with no malignant sign had genetic mutation of SDHB. Further accumulation of cases is necessary to confirm the association between SDHB mutation and malignant potential.

The role of atopy in the clinical course of pulmonary sarcoidosis in the Japanese population.

Sarcoidosis is a multisystem disorder characterized by a T-helper 1 (Th1)-mediated immune response. Conversely, atopy is characterized by the presence of a specific immunoglobulin E (IgE) E response in association with a Th2-type immune response. Several epidemiological studies have shown that atopic status influences disease activity and clinical course for several Th1-mediated diseases. The aim of this study was to evaluate associations between atopic status and clinical findings of sarcoidosis. We further evaluated the impact of atopic status on the clinical course of pulmonary sarcoidosis. We defined atopy as a positive specific IgE response to at least one common inhaled allergen (multiple antigen simultaneous test scores, lumicount of >1.01). Subjects comprised 134 patients given a diagnosis of sarcoidosis between 2000 and 2006, divided into atopic and nonatopic groups. Several clinical findings were compared between the two groups. Furthermore, 100 subjects observed 2 years after diagnosis were divided into resolving and persistent clinical course groups according to chest radiography and associations with atopic status were evaluated. Atopy was more prevalent among men than women (p = 0.009) and subjects with atopy were younger (p = 0.002) and showed less frequent lung parenchymal lesions (stages II and III; p = 0.018) compared with subjects without atopy. The prevalence of atopy was higher in the resolving clinical course group than in the persistent clinical course group (p = 0.002) and this association was independent of sex, age, presence of lung parenchymal lesions, and presence of extrapulmonary lesions (p = 0.037). Classification of sarcoidosis based on atopic status might be useful for predicting the clinical course of pulmonary sarcoidosis.

Angiotensin II receptor blocker, valsartan, increases myocardial blood volume and regresses hypertrophy in hypertensive patients.

BACKGROUND: Although a reduction in myocardial blood volume (MBV), an in vivo index of the myocardial microvasculature, measured by myocardial contrast echocardiography in patients with hypertension (HT), can be demonstrated, it is still unknown whether a decreased MBV can be improved by antihypertensive treatment. METHODS AND RESULTS: Eleven HT patients (mean age 58 years, 7 men) with left ventricular hypertrophy (LVH) and 10 age- and sex-matched normal controls were studied. Harmonic power Doppler images were acquired at end-diastole of every 6(th) beat and MBV was calculated as 10(X/10)x100%, where X (dB) is myocardial contrast intensity minus the contrast intensity of the adjacent intracavity blood pool. Baseline blood pressure (BP) and left ventricular mass index (LVMI) in the HT patients were higher and MBV was lower than in the controls (2.52 +/-0.37% vs 3.31 +/-0.61%, P<0.01). MBV did not correlate with mean BP, but was inversely correlated with LVMI (r=0.61, P<0.01). After treatment with valsartan for 6 months, LVMI significantly decreased and MBV increased (2.72 +/-0.26%, P<0.05 vs baseline) in the patients with HT. There was a significant inverse correlation between the changes in MBV and those of LVMI (r=0.62, P<0.05), but not between MBV and mean BP. CONCLUSIONS: Valsartan, an angiotensin II receptor blocker, corrected the decreased MBV in association with regression of LVH in patients with HT.

[Evaluation of HbA1c using different methods in haemoglobin variant, Hb J-Bangkok].

A 31-year-old Japanese man with haemoglobin variant, Hb J-Bangkok [beta56 (D7) Gly-->Asp], was found by discrepant values between HbA1c and glycated-albumin. We measured HbA1c using three different methods, HPLC, enzyme assay and turbidimetric immunoassay. HbA1c value measured by HPLC was much lower than those by others. Furthermore, we estimated calculated glyco-haemoglobin value measured by high-resolution HPLC, revealing that HbA1c values measured by enzyme assay and turbidimetric immunoassay were comparable with calculated value. When measuring HbA1c value in haemoglobin variant, Hb J Bangkok, enzyme assay and turbidimetric immunoassay are useful methods.

Attenuated aerobic exercise capacity in CD36 deficiency.

BACKGROUND: An important role of CD36 in muscle fatty acid (FA) uptake has been shown in CD36-knockout or CD36-overexpressed mice. FA is a predominant substrate in energy production during light exercise below the anaerobic threshold (AT). We studied whether aerobic exercise capacity in humans could be affected by CD36 deficiency. METHODS: We investigated the ventilatory threshold (VT) and serum FA changes in normal participants (n = 22) and participants with CD36 deficiency (n = 12) during pedalling on a cycle ergometer. RESULTS: In participants with CD36 deficiency, FA levels were not reduced at peak work rate, whereas FA levels decreased by about 50% in normal participants. Participants with CD36 deficiency showed significantly lower VT than normal participants. A significant correlation was observed between VT and percentage changes in FA at peak work rate. CONCLUSION: This study found reduced FA utilisation and an attenuated aerobic exercise capacity in CD36 deficiency, indicating that CD36-mediated FA oxidation is an important determinant for aerobic exercise capacity in humans.

[Advancement of platelet activation measurement: focusing on platelet-derived microparticle measurement].

The assessment of the extent of platelet activation in various thrombotic disorders is important to detect thrombotic tendencies and monitor antiplatelet therapy. Various methods (platelet factor 4: PF4, beta-thromboglobulin: beta-TG, CD62P, PAC-1, etc.) are used as markers of platelet activation. Platelet-derived microparticles (PDMP) are submicroscopic vesicles released by platelets during activation, and are used as a marker of platelet activation. PDMP are usually determined by flow cytometry. An enzyme-linked immunosorbent assay (ELISA) method in which PDMP are detected with the antibody of CD42a and CD42b, was recently reported. The PDMP sample for ELISA can be preserved, and standardization is also easy. It is expected to become an evaluation method of platelet function in vivo.

Platelet reactivity in twin pregnancies.

BACKGROUND: Gestational thrombocytopenia is more likely to occur in twin than singleton pregnancies. However, it is unclear whether platelets are more reactive in twin than singleton pregnancies. METHODS: Changes in spontaneous platelet aggregation and concomitant fall in platelet count were examined over 90min after blood sampling in 171 and 52 citrated whole blood (CWB) samples from 59 and 17 women with singleton and twin pregnancies, respectively. Soluble P-selectin (sP-selectin) levels in the plasma were also determined. RESULTS: CWB 60min after blood sampling during 2nd trimester exhibited significantly larger numbers of platelet aggregates (1297±1600 vs. 497±432/µl, P=0.040) concomitant with significantly greater net decrease in platelet count (152±55 vs. 115±45×10(9)/µl, P=0.036) in twin than singleton pregnancies, respectively. This was followed by significantly lower 3rd trimester platelet count (181±43 vs. 229±62×10(9)/l, P=0.009) with significantly greater mean platelet volume (8.0±1.2 vs. 7.1±1.1fl, P=0.021) in twin than singleton pregnancies, respectively. The 3rd trimester sP-selectin per platelet was significantly higher in twin than singleton pregnancies. CONCLUSIONS: Platelets were more reactive in the 2nd trimester of twin than singleton pregnancies. This enhanced platelet reactivity may explain the decreased platelet count in the 3rd trimester of twin pregnancy.