Direct evaluation of cohesin-mediated sister kinetochore associations at meiosis I in fission yeast

Kinetochores drive chromosome segregation by mediating chromosome interactions with the spindle. In higher eukaryotes, sister kinetochores are separately positioned on opposite sides of sister centromeres during mitosis, but associate with each other during meiosis I. Kinetochore association facilitates the attachment of sister chromatids to the same pole, enabling the segregation of homologous chromosomes toward opposite poles. In the fission yeast, Schizosaccharomyces pombe, Rec8-containing meiotic cohesin is suggested to establish kinetochore associations by mediating cohesion of the centromere cores. However, cohesin-mediated kinetochore associations on intact chromosomes have never been demonstrated directly. In the present study, we describe a novel method for the direct evaluation of kinetochore associations on intact chromosomes in live S. pombe cells, and demonstrate that sister kinetochores and the centromere cores are positioned separately on mitotic chromosomes but associate with each other on meiosis I chromosomes. Furthermore, we demonstrate that kinetochore association depends on meiotic cohesin and the cohesin regulators Moa1 and Mrc1, and requires mating-pheromone signaling for its establishment. These results confirm cohesin-mediated kinetochore association and its regulatory mechanisms, along with the usefulness of the developed method for its analysis. This article has an associated First Person interview with the first author of the paper.

Chiasmata and the kinetochore component Dam1 are crucial for elimination of erroneous chromosome attachments and centromere oscillation at meiosis I

Establishment of proper chromosome attachments to the spindle requires elimination of erroneous attachments, but the mechanism of this process is not fully understood. During meiosis I, sister chromatids attach to the same spindle pole (mono-oriented attachment), whereas homologous chromosomes attach to opposite poles (bi-oriented attachment), resulting in homologous chromosome segregation. Here, we show that chiasmata that link homologous chromosomes and kinetochore component Dam1 are crucial for elimination of erroneous attachments and oscillation of centromeres between the spindle poles at meiosis I in fission yeast. In chiasma-forming cells, Mad2 and Aurora B kinase, which provides time for attachment correction and destabilizes erroneous attachments, respectively, caused elimination of bi-oriented attachments of sister chromatids, whereas in chiasma-lacking cells, they caused elimination of mono-oriented attachments. In chiasma-forming cells, in addition, homologous centromere oscillation was coordinated. Furthermore, Dam1 contributed to attachment elimination in both chiasma-forming and chiasma-lacking cells, and drove centromere oscillation. These results demonstrate that chiasmata alter attachment correction patterns by enabling error correction factors to eliminate bi-oriented attachment of sister chromatids, and suggest that Dam1 induces elimination of erroneous attachments. The coincidental contribution of chiasmata and Dam1 to centromere oscillation also suggests a potential link between centromere oscillation and attachment elimination.

Efficacy and outcomes of balloon pulmonary angioplasty in elderly vs non-elderly chronic thromboembolic pulmonary hypertension patients

Introduction

Balloon pulmonary angioplasty (BPA) has been reported as an effective and safe treatment for patients with chronic thromboembolic pulmonary hypertension (CTEPH). However, its safety and efficacy in elderly patients remains unknown.

Purpose

We investigated the effect of BPA on hemodynamics and respiratory parameters, functional capacity, and short- and long-term outcome in elderly patients.

Methods

From November 2012 to May 2018, 141 consecutive CTEPH patients who underwent BPA in a single university hospital were enrolled (age: 65 [54.5–74] years old, WHO functional class [WHO-FC] II/III/IV; 35/96/10). Patients were divided into two groups according to the age; elderly (≥75 years, N=32) and young groups (<75 years, N=109). Hemodynamics (right-sided heart catheterization), biomarkers (brain natriuretic peptide), respiratory function (spirometry and diffusion capacity measurement), and functional capacity (6-minute walk distance [6MWD] and WHO-FC) were evaluated at baseline and 1-year post BPA. Procedure-related complications (in hospital death, use of percutaneous cardiopulmonary support [PCPS], and pulmonary injury) and all cause death during the follow up period were also assessed.

Results

At baseline, although elderly group had less severe hemodynamics (mPAP: 33.1±6.7 vs 39.0±11.8 mmHg, p<0.05), they had poor exercise capacity and reduced pulmonary diffusion capacity, compared with young group (6MWD: 264.6±101.3 vs 369.7±105.2 m, %DLco: 42.0±12.0 vs 50.2±12.7%, all p<0.05). BPA improved hemodynamics, biomarkers, exercise capacity, and pulmonary diffusion capacity in both elderly and young groups (all p<0.05). There was no in-hospital death or use of PCPS in both groups, although the incidence of pulmonary injury was higher in elderly group (14.3% vs 5.3%, p<0.01). Under the normalized hemodynamics 1-year after BPA in both groups, exercise capacity and pulmonary diffusion capacity were worse in the elderly group than young groups (p<0.01). The incidence of all-cause death in the follow up period was higher in elderly group, all of which were due to non-pulmonary hypertension (PH)-related death (p<0.01).

Conclusion

BPA was effective in improving hemodynamics and respiratory parameters and functional capacity, in associated with no critical complication, regardless of the age. Elderly patients who were treated with BPA were associated with higher incidence of non-PH-related death.

Changes of mean PAP in the two groups

Funding Acknowledgement

Type of funding source: None

Association Between the Fertile Period and Live Birth Post-Kidney Transplantation: A Retrospective Single-Center Cohort Study

BACKGROUND

Despite restoration of fertility after kidney transplantation, the benefit is limited in female kidney recipients. Our objective is to determine the reasons for this discrepancy.

METHODS

We evaluated 315 women who underwent kidney transplantation from 1983 to 2015 (a median of age at transplantation [10th-90th percentile] of 32 years [7-55 years]); 230 recipients between the ages of 15 to 49 years old as of March 2016 were observed.

RESULTS

We experienced 10 abortions and 21 live births from our 23 recipients and 2 abortions and 7 live births in 7 recipients from other transplant center. The live birth rate was 8.9 per 1000 female transplant recipients of childbearing age. Seven recipients received either treatments of artificial insemination or in vitro fertilization. Average age at pregnancy was 33.2 ± 3.2 years old, and the fertile period post-transplantation was longer in recipients with live births than those without live births (14.1 ± 7.1 vs 9.9 ± 7.3 years, P < .05). In 42.9% of recipients with live birth, pregnancy-induced hypertension was observed in the last trimester. The gestational age and the average birth weight were 32.8 ± 5.0 months and 2184 ± 632 g, respectively. During follow-up of 14.5 years, there was one case of graft loss, which is a rate of 2.5 per 1000 female recipients.

CONCLUSION

Although pregnancy complications are often observed in kidney recipients, graft survival is less influenced by pregnancy. Importantly, kidney disease at childbearing age disrupts pregnancy even after kidney transplantation.

Pharmacokinetic Profile of Twice- and Once-daily Tacrolimus in Pediatric Kidney Transplant Recipients

BACKGROUND

The aim of this study was to assess the differences in pharmacokinetic (PK) profiles after the 1:1 ratio-based conversion from a twice-daily to a once-daily tacrolimus formulation (TD-TAC and OD-TAC, respectively) in pediatric recipients of kidney transplants.

METHODS

TD-TAC was initially administered to 29 pediatric patients who underwent kidney transplantations between April 2010 and September 2015 and were then subsequently switched to OD-TAC. The switch dose ratio was 1:1, and the 24-hour complete PK parameter assessment was performed before and after the regimen was changed from TD-TAC to OD-TAC.

RESULTS

The mean total daily dose at baseline was 5.5 ± 2.9 mg (0.18 ± 0.10 mg/kg body weight). Consecutive PK studies revealed no significant difference in the mean time to achieve maximum concentrations and the area under the concentration-time curve from 0 to 24 hours (AUC_0-24) of both drug formulations. However, the mean trough concentration (C_min) and the maximum concentration of OD-TAC were 22% and 6% lower and higher, respectively, than those of TD-TAC. Therefore, a better correlation was observed between the AUC_0-24 and C_min of OD-TAC than between those of TD-TAC.

CONCLUSIONS

After the change from TD-TAC to OD-TAC, the AUC_0-24 values were equivalent despite a 22% reduction in C_min. C_min may therefore be an excellent predictor in the therapeutic drug monitoring of OD-TAC because of its superior correlation with AUC_0-24.

Technical Note. Labral-ligamentous complex of the shoulder: Evaluation with double oblique axial MR arthrography

Purpose: To assess the ability of double oblique axial (DOA) MR arthrography in evaluating labral-ligamentous complex compared with conventional axial (CA) MR arthrography.

Material and Methods: MR arthrography of 51 shoulders, subsequently examined with arthroscopy, were retrospectively reviewed. DOA imaging was performed in all 51 shoulders and both DOA and CA imaging in 37 using a 1.5 T unit with gradient recalled-echo T2*-weighted sequences. DOA imaging was performed using perpendicular planes to the long axis of the glenoid fossa obtained by an oblique sagittal scout image. We compared the ability of DOA with that of CA MR arthrography to assess labral injuries and to demonstrate the whole length of the anterior band of the inferior glenohumeral ligament (AIGHL), which were shown to be intact by arthroscopy.

Results: For anterior labral injuries, sensitivity and specificity were 87% and 93% with CA, and 94% and 100% with DOA imaging, respectively. For posterior labral injuries, sensitivity and specificity were 47% and 100% with CA, and 79% and 96% with DOA imaging, respectively. There were no statistically significant differences between CA and DOA images, except for the ability to diagnose posterior labral injuries, where DOA imaging had a significant superior sensitivity ( p = 0.0327). DOA images also demonstrated the whole length of the intact AIGHL in 10 of 11 shoulders, while CA imaging showed this in only 3 of 11.

Conclusion: DOA imaging was equal or better than CA imaging for evaluating the labral-ligamentous complex.

Chiasmata promote monopolar attachment of sister chromatids and their co-segregation toward the proper pole during meiosis I

The chiasma is a structure that forms between a pair of homologous chromosomes by crossover recombination and physically links the homologous chromosomes during meiosis. Chiasmata are essential for the attachment of the homologous chromosomes to opposite spindle poles (bipolar attachment) and their subsequent segregation to the opposite poles during meiosis I. However, the overall function of chiasmata during meiosis is not fully understood. Here, we show that chiasmata also play a crucial role in the attachment of sister chromatids to the same spindle pole and in their co-segregation during meiosis I in fission yeast. Analysis of cells lacking chiasmata and the cohesin protector Sgo1 showed that loss of chiasmata causes frequent bipolar attachment of sister chromatids during anaphase. Furthermore, high time-resolution analysis of centromere dynamics in various types of chiasmate and achiasmate cells, including those lacking the DNA replication checkpoint factor Mrc1 or the meiotic centromere protein Moa1, showed the following three outcomes: (i) during the pre-anaphase stage, the bipolar attachment of sister chromatids occurs irrespective of chiasma formation; (ii) the chiasma contributes to the elimination of the pre-anaphase bipolar attachment; and (iii) when the bipolar attachment remains during anaphase, the chiasmata generate a bias toward the proper pole during poleward chromosome pulling that results in appropriate chromosome segregation. Based on these results, we propose that chiasmata play a pivotal role in the selection of proper attachments and provide a backup mechanism that promotes correct chromosome segregation when improper attachments remain during anaphase I.

First Living Related Kidney Transplantation Results in Excellent Outcomes for Small Children

OBJECTIVE

The aim of this study was to evaluated the outcomes of living related kidney transplantation in small children.

MATERIALS AND METHODS

Ten pediatric patients with body weights less than 10 kg received parental kidney transplants (five mothers and five fathers). An intra-abdominal approach was used in nine children and a retroperitoneal approach in one child. Bilateral, left, or right nephrectomy was performed in seven, two, and one child, respectively. Immunosuppression consisted of either cyclosporine (n = 7) or tacrolimus (n = 3) with either mizoribine (n = 4) or mycophenolate mofetil (MMF) (n = 5) or azathioprine (n = 1), and methylprednisolone (n = 10). Antilymphocyte globulin was used in the first series of four children; basiliximab in the most recent five children.

RESULTS

All renal allografts functioned immediately after transplantation despite the mismatched size of the large renal allografts. Nine of 10 children were alive with a functional allograft at 6 to 196 months posttransplantation. One child died of intra-abdominal bleeding 5 days posttransplantation. One child has suffered chronic allograft nephropathy 11 years posttransplantation (serum creatinine 3.3 mg/dL). The remaining eight children display good renal function (serum creatinine = 0.2 to 1.43 mg/dL). Steroids were withdrawn in eight of nine children; one child continues on alternative-day therapy. One child (LD55) exceeded the mean standard height. The most recent height standard deviation (SD) scores were superior (-1.75 +/- 1.39 [-3.83 to 0.54]; P < .0082) to those at transplantation (-2.91 +/- 0.79 [-2.00 to -4.14]).

CONCLUSIONS

The outcomes of living related kidney transplantation in small children were excellent despite the operative risks and the difficulty of cardiovascular and fluid management. Transplantation for small children appears to result in much better quality of life and growth than dialysis.

The Pathologic Impact of Tacrolimus on Protocol Biopsy in Renal Transplant Patients With Basiliximab-Based Immunosuppression

Forty-two ESRD patients underwent renal transplantation using basiliximab (mean age: 30.6 +/- 18.6 years at transplantation; male: 50%; ESRD duration: 51.6 +/- 13.0 months) between February, 2000 and July, 2003. All patients had a protocol biopsy on the day of transplant, on discharge from the hospital (35.5 +/- 13.2 days), and at 1 year after transplant. The immunosuppression included a calcineurin inhibitor, basiliximab, mycophenolate mofetil (MMF), and methylprednisolone. While 16 patients used tacrolimus (FK group: 29.4 +/- 16.6 years old), 26 patients used cyclosporine (CsA group: 31.4 +/- 20.1 years old). Protocol biopsies were graded according to the Banff 97 classification. The incidence of acute rejection episodes within 1 year was greater in the CsA (15%) than the FK group (6%). Serum creatinine at hospital discharge was similar (CsA: 1.01 +/- 0.59 mg/dL, FK: 0.97 +/- 0.49, p = .18); however creatinine at 1 year differed significantly (CyA: 1.22 +/- 0.88 mg/dL, FK: 0.92 +/- 0.39, P = .03). There was a trend toward an increase in the score of interstitial inflammations in the CsA group, while it remained constant in the FK cohort (P = .05 at 1 year between the two groups). Other pathologic scores (t, ci, ct, cv, ah) did not differ between the groups at 1 year. Although there were no differences in the demographics between the two groups, there were several trends toward better renal function in the FK group.

Baseline Glomerular Sclerosis Influences Morphological Changes, But Not Level of Serum Creatinine

The aim of this study was to investigate whether glomerular sclerosis (GS) at the time of engraftment affects subsequent morphology and clinical course of renal allografts. Eighty-one renal transplant recipients were recruited for this study. Protocol biopsies of the renal allografts were performed at engraftment, as well as at 1, 3, 5, and 7 years after transplantation. All cases were divided into 2 groups based on the presence of GS at engraftment, namely, non-GS and GS groups. Morphological changes in the renal allografts were graded from 0 to 3+ based on the severity of chronic allograft nephropathy (CAN) of the Banff classification based on 5 factors: percentage of GS, extent of interstitial fibrosis, tubular atrophy, arterial intimal thickening, and arteriolar hyalinosis. Furthermore, the level of serum creatinine (s-Cr) at each year was examined by recipient age and gender, donor age and gender, type of donor (living/cadaver), delayed graft function, acute rejection within 1 year after transplantation, mean blood pressure, and use of calcineurin inhibitors as well as the presence of GS at engraftment. The extent of GS at engraftment significantly correlated with donor age (P = .0038) but with a weak correlation coefficient. Although the severity of CAN developed gradually in both non-GS and GS groups, differences in morphological changes at engraftment between the 2 groups persisted throughout 7 years. Donor age and recipient gender influenced s-Cr significantly. In conclusion, the presence of GS at engraftment aggravates subsequent morphological changes and affects short-term but not long-term allograft prognosis.

BK virus nephropathy in a patient with ABO-incompatible renal transplantation

A 43-year-old woman with end-stage renal disease originating from IgA nephropathy entered chronic haemodialysis therapy. She then received an ABO-incompatible living related renal transplantation. Initial immunosuppression consisted of azathioprine, methylprednisolone and tacrolimus. At 155 days after transplantation, the azathioprine was changed to mycophenolate mofetil for continuous graft dysfunction. Furthermore, a total of three courses of anti-rejection therapy was given. At 665 days after transplantation, diagnosis of BK-virus nephropathy was made by immunohistochemical analysis and viral DNA assay. Therefore the immunosuppression therapy was reduced for graft dysfunction. All five renal biopsy specimens were examined retrospectively in order to determine when the BK virus nephropathy had developed. The expressions of SV40 large T antigens were detected from the third (117 days) to the fifth (665 days) biopsies, with increasing numbers of SV40 large T antigen positive cells. In addition, many cells contained inclusion bodies which were already present in the urinary sediment for 3 months post-transplantation. Although it is difficult to make a diagnosis of early stage of BKVN, we have to consider with caution if urinary cells with inclusion body are seen. Awareness of BKVN at the earliest opportunity is important in order to avoid over-immunosuppression.

CD8 T cell of donor splenocyte mixed with bone marrow cells is more effective than CD4 T cell for induction of donor-specific tolerance in sublethally irradiated mice

BACKGROUND

We previously demonstrated that even a low dose of bone marrow cells (BMCs) established donor-specific tolerance if mixed with splenocytes (SPLCs). In this study, T-cell subsets CD4 (CD4SP) and CD8 (CD8SP) of donor SPLCs were investigated for their contribution to the enhancement of BMC engraftment leading to donor-specific tolerance in sublethally irradiated mice.

METHODS

Sublethally irradiated C57BL/6 recipient mice were intravenously injected BMCs mixing with CD4SP or CD8SP harvested from BALB/c donor mice. The degree of chimerism in the peripheral blood lymphocytes (PBLs) and in the SPLCs was analyzed using FACS, mixed lymphocyte reaction, and skin graft transplantation 3 months after injection.

RESULTS

Recipients injected with 3 x 10(6) donor BMCs admixed with 10 x 10(6) donor CD8SP established chimerism. However, recipients injected with the same dose of BMCs admixed with 5 x 10(6) CD4SP, 10 x 10(6) CD4SP, and 5 x 10(6) CD8SP did not established chimerism. CD8SP contained 44% of Ly6A/E (Stem Cell Antigen-1 (Sca-1))-positive cells based on FACS analysis, whereas only 6% of CD4SP were positive for Ly6A/E. MLR supernates of donor SPLCs chimeric mice using admixture with CD8SP dominated by Th2 cytokines. In contrast, mixting with MLR supernates from failed chimera showed dominant Th1 cytokines.

CONCLUSIONS

CD8SP seems to make a major contribution to enhance BMC engraftment and induce donor-specific tolerance. Ly6A/E (Sca-1)-positive cells need to be further investigated for their contribution to the establishment of chimerism.

Labral-ligamentous complex of the shoulder. Evaluation with double oblique axial MR arthrography

PURPOSE

To assess the ability of double oblique axial (DOA) MR arthrography in evaluating labral-ligamentous complex compared with conventional axial (CA) MR arthrography.

MATERIAL AND METHODS

MR arthrography of 51 shoulders, subsequently examined with arthroscopy, were retrospectively reviewed. DOA imaging was performed in all 51 shoulders and both DOA and CA imaging in 37 using a 1.5 T unit with gradient recalled-echo T2*-weighted sequences. DOA imaging was performed using perpendicular planes to the long axis of the glenoid fossa obtained by an oblique sagittal scout image. We compared the ability of DOA with that of CA MR arthrography to assess labral injuries and to demonstrate the whole length of the anterior band of the inferior glenohumeral ligament (AIGHL), which were shown to be intact by arthroscopy.

RESULTS

For anterior labral injuries, sensitivity and specificity were 87% and 93% with CA, and 94% and 100% with DOA imaging, respectively. For posterior labral injuries, sensitivity and specificity were 47% and 100% with CA, and 79% and 96% with DOA imaging, respectively. There were no statistically significant differences between CA and DOA images, except for the ability to diagnose posterior labral injuries, where DOA imaging had a significant superior sensitivity (p=0.0327). DOA images also demonstrated the whole length of the intact AIGHL in 10 of 11 shoulders, while CA imaging showed this in only 3 of 11.

CONCLUSION

DOA imaging was equal or better than CA imaging for evaluating the labral-ligamentous complex.

Olfactory neuroblastoma visualized by Technetium-99m-ECD SPECT

We describe a case of olfactory neuroblastoma diagnosed by 99mTc-ECD SPECT. Although MRI and CT are very important for delineating these tumors, they are, by no means, specific for neuroblastomas. 131I-MIBG scintigraphy, the standard method for imaging tumors of neural crest origin, also failed to detect a histologically proven esthesioneuroblastoma.

Dissociation of brain edema induced by cold injury in rat model: MR imaging and perfusion studies with 14C-iodo-antipyrine

The purpose of this study is to confirm whether T2-weighted imaging and perfusion imaging, i.e. autoradiogram of 14C-iodoantipyrine, on the course of brain edema correspond to each other or not. Cold injured rat brains were used as a model and were sequentially examined by both methods and compared with each other and with histological specimens. Special focus relies on the time changes in the lesions. High SI of T2-weighted images were observed and the percentages in the high SI area to the total brain area in the same slice were 4.7 +/- 0.31, 5.6 +/- 0.46 and 3.4 +/- 0.42 for 6, 24 and 48 hours, respectively. By contrast, low perfusion areas were indicated in the perfusion study and their percentages were 4.6 +/- 0.55, 5.6 +/- 0.86 and 2.4 +/- 0.35 for 6, 24 and 48 hours, respectively. At 48 hours after cold injury, low perfusion areas were smaller than hi

[Gadolinium-enhanced MR imaging, T2-weighted MR imaging, and transurethral ultrasonography]

PURPOSE

To assess the value and problems of dynamic gadolinium-enhanced MR imaging, T2-weighted MR imaging, and transurethral ultrasonography(TUUS) in staging of urinary bladder cancer.

MATERIALS AND METHODS

Dynamic gadolinium-enhanced MR imaging and FSE T2-weighted MR imaging of 64 patients with urinary bladder cancer who subsequently had surgery were retrospectively reviewed and compared with TUUS findings.

RESULTS

Specificity for muscular invasion was 90.5% with TUUS, significantly better than with dynamic MR imaging (64.9%) (p < 0.05). The rates of overestimation of superficial cancer(pT1) with dynamic MRI and T2-weighted MR imaging were 35.1%(13/37) and 24.3%(9/37), respectively. The staging accuracy of invasive cancer(pT2 or over) was 85.2% with dynamic MR imaging, which was better than the rate of 75.0% achieved with T2-weighted MR imaging.

CONCLUSION

Although TUUS was a better modality for diagnosing superficial cancer(pT1), dynamic MR imaging was found to be better for diagnosing invasive(pT2 or over) cancer.

Determination of stereochemical configuration of the glycerol moieties in glycoglycerolipids by chiral phase high-performance liquid chromatography

This study reports a simple and sensitive method for determining the absolute configuration of the glycerol moieties in glycoglycerolipids. The method is based on chiral phase high-performance liquid chromatography (HPLC) separations of enantiomeric di- and monoacylglycerols released from glycosyldi- and monoacylglycerols, respectively, by periodate oxidation followed by hydrazinolysis. The released di- and monoacylglycerols were chromatographed as their 3,5-dinitrophenylurethane (3,5-DNPU) and bis(3,5-DNPU) derivatives, respectively. The derivatives were separated on two chiral phases of opposite configuration, (R)- and (S)-1-(1-naphthyl)ethylamine polymers for diacylglycerols and N-(R)- -(1-naphthyl)ethylaminocarbonyl-(S)-valine and N-(S)-1 -(1-naphthyl)ethylamino-carbonyl-(R)-valine for monoacylglycerols. Clear enantiomer separations, which permit the assignment of the glycerol configuration, were achieved for sn-1,2(2,3)-diacyl- and sn-1(3)-monoacylglycerols generated from linseed oil triacylglycerols by partial Grignard degradation on all the chiral stationary phases employed. Using the method, we have determined the glycerol configuration in the glycosyldiacylglycerols (monogalactosyl-, digalactosyl-, and sulfquinovosyldiacylglycerols) and glycosylmonoacylglycerols (monogalactosyl-, digalactosyl-, and sulfoquinovosylmonoacylglycerols) isolated from spinach leaves and the coralline red alga Corallina pilulifera. The results clearly showed that the glycerol moieties in all the glycoglycerolipids examined have S-configuration (sn-1,2-diacyl- and sn-1-monoacylglycerols). The new method demonstrates that chiral phase HPLC provides unambiguous information on the configuration of the glycerol backbone in natural glycosyldi- and monoacylglycerols, and that the two-step liberation of the free acylglycerols does not compromise glycerol chirality.

High-performance liquid chromatographic resolution of reverse isomers of 1,2-diacyl-rac-glycerols as 3,5-dinitrophenylurethanes

The resolution of reverse isomers remains a major unsolved problem in glycerolipid chromatography. We have investigated the separation of the reverse isomers of 1,2-diacyl-rac-glycerols under a variety of high-performance liquid chromatography (HPLC) conditions. The reverse isomers of diacylglycerols having various pairs of acyl groups including short and highly unsaturated chains, which were prepared by partial Grignard degradation of the corresponding triacylglycerols, were chromatographed as 3,5-dinitrophenylurethanes. Excellent resolution was achieved for the reverse isomers of very different pairs of acyl groups, such as acetate-palmitate and docosahexaenoate-palmitate, by chiral-phase HPLC on columns containing (R)- and (S)-1-(1-naphthyl)ethylamine polymeric phases, reversed-phase HPLC on a highly efficient C18 column (4 microm particle size) and silver ion HPLC on a silver loaded cation-exchange column. The chiral-phase HPLC also permitted complete enantiomer resolution for all the reverse isomers examined. No satisfactory resolution by any of the HPLC methods, however, was obtained for the reverse isomers possessing minor differences in chain lengths and degree of unsaturation, such as laurate-palmitate and oleate-linoleate. The limitations of resolution and characteristics of elution are described.

A case of living-related partial liver transplantation using the right gastroepiploic artery for hepatic artery reconstruction

A 13-year-old boy with liver cirrhosis underwent living-related partial liver transplantation with a left lobe from his mother. A standard hepatic artery reconstruction using the recipient right hepatic artery was anticipated. Unfortunately, the recipient hepatic artery was found to be severely arteriosclerotic and was unsuitable for reconstruction. Instead, the right gastroepiploic artery, measuring 2.0 mm in diameter, was mobilized and was anastomosed to the left hepatic artery of the graft in an end-to-end fashion. Arterial blood flow was satisfactory. The patient's postoperative course was uneventful, and he was transferred to a floor bed on the 5th postoperative day.

Liquid chromatography with particle-beam electron-impact mass spectrometry of diacylglycerol nicotinates

Several synthetic diacylglycerols and natural mixtures derived from soybean, egg yolk, and bovine liver phosphatidylcholines were examined in the form of nicotinate derivatives by liquid chromatography with particle-beam electron-impact mass spectrometry. High-performance liquid chromatography was carried out in the reversed-phase mode with a base-deactivated octyl-/octadecylsilyl stationary phase. The nature (size and degree of unsaturation) of the acyl residues was readily determined from the mass spectra. Uniquely, the positions of the double bonds could be deduced, although this became increasingly difficult as the degree of unsaturation of diacylglycerols containing mixed acyl residues increased. Reverse 1,2-diacylglycerol isomers could be distinguished by their mass spectra.

[MR diagnosis of internal derangement of the knee by SE T1 and GRE T2* weighted images: evaluation of 300 arthroscopically proven knees]

To evaluate whether or not the combination of sagittal and coronal spin-echo (SE) T1 and sagittal gradient echo (GRE) T2* weighted imaging is adequate to diagnose internal derangement of the knee, a study was done in 300 knees of 293 consecutive patients who underwent both MR imaging of the knee and arthroscopy. In prospective analysis, the MR imaging had an accuracy, sensitivity and specificity of more than 90% in the evaluation of medial meniscus (MM) and of 97% in the evaluation of anterior cruciate ligament (ACL). In the evaluation of lateral meniscus (LM), accuracy was 83%, sensitivity 76%, and specificity 88%. In a review of false-negative MR diagnoses (n = 42) of menisci, the most significant lesion was not in the meniscus but in the ACL in 32 knees (76%). Conservative treatment was selected in 25 knees (60%), rather than partial meniscectomy (n = 13) or meniscoresis (n = 4). There were 21 false-positive MR diagnoses of menisci even in retrospective analysis, and 17 of them (81%) had findings of tear in the posterior zone, which is known to be a difficult area for arthroscopic examination. The results were similar to those of other authors' with SE T1 and/or proton density and T2 weighted images. The combination of sagittal and coronal SE T1 and sagittal GRE T2* weighted images could be sufficient as a routine MR protocol for diagnosing the internal derangement of the knee.

Reassessment of stereochemical configuration of natural phosphatidylglycerols by chiral-phase high-performance liquid chromatography and electrospray mass spectrometry

Using chiral-phase high-performance liquid chromatography (HPLC) and electrospray ionization-mass spectrometry (ESI/MS), we have redetermined the stereochemical configuration of some natural and synthetic phosphatidylglycerols (PG). For this purpose, the synthetic and natural PG were converted to their bis-3,5-dinitrophenylurethanes (DNPU), which were separated by HPLC using two columns having chiral phases of opposite configuration, (R)-(+)- and (S)-(-)-1-(1-naphthyl)ethylamine polymers. The molecular species were identified by on-line negative-ion ESI/MS. Absolute configurations of the resolved peaks were assigned by comparison with the elution order of the corresponding 1(3)-monoacyl-sn-glycerol enantiomers as bis-DNPU derivatives on the same column. The results clearly showed that the PG from cabbage leaf lipids and soybean phospholipids consisted of single R,S isomers (1,2-diacyl-sn-glycero-3-phospho-1'-sn-glycerols), despite the presence of nonstereospecific phospholipase D in the tissues. On the other hand, the PG derived from egg yolk phosphatidylcholine and glycerol by transphosphatidylation with cabbage phospholipase D was a mixture of 45% R,S isomers (1, 2-diacyl-sn-glycero-3-phospho-1'-sn-glycerols) and 55% R,R isomers (1,2-diacyl-sn-glycero-3-phospho-3'-sn-glycerols). The PG from Escherichia coli lipids was a mixture of 89% R,S and 11% R,R isomers. The present study demonstrates that chiral-phase HPLC and negative-ion ESI/MS provide direct and unambiguous information about the configuration, identity, and quantity of molecular species in natural and synthetic PG.

Delivery of lymph node-targeted adriamycin by gastric submucosal liposomal injection in rabbits

We investigated the feasibility of specifically delivering adriamycin (ADR) to the regional lymph nodes via gastric submucosal injection of liposomal adriamycin (Lipo-ADR) in a rabbit model. We determined the tissue distribution of ADR for up to 7 days after the gastric submucosal injection of Lipo-ADR (0.4 mg/kg of ADR potency) and i.v. administration of an equal dose of free adriamycin (F-ADR). The area under the ADR concentration-time curve (AUC) of the regional lymph nodes was 85.4 micrograms.day/g after gastric submucosal injection of Lipo-ADR and 8.44 micrograms.day/g after i.v. administration of F-ADR. The targeting index of the regional lymph nodes, defined as the ratio of the AUC after gastric submucosal injection of Lipo-ADR to the AUC after i.v. administration of F-ADR, was 10.1. Gastric submucosal injection of Lipo-ADR enhanced lymph node-specific delivery of ADR compared with i.v. administration of F-ADR. The targeting index was 0.47 for the heart, 0.25 for the bone marrow, and 0.41 for the spleen, indicating that gastric submucosal injection of Lipo-ADR reduced delivery of ADR to these organs, as compared with i.v. administration of F-ADR. These data demonstrate that gastric submucosal injection of Lipo-ADR is well suited for specific delivery of ADR to the regional lymph nodes, suggesting that this method of administration may be useful in delivering preoperative adjuvant chemotherapy for preventing gastric cancer recurrence.

Stereospecificity of monoacylglycerol and diacylglycerol acyltransferases from rat intestine as determined by chiral phase high-performance liquid chromatography

Using chiral phase high-performance liquid chromatography of diacylglycerols, we have redetermined the ratios of 1,2-/2,3-diacyl-sn-glycerols resulting from acylation of 2-monoacylglycerols by membrane bound and solubilized triacylglycerol synthetase of rat intestinal mucosa. With 2-oleoyl[-3H]glycerol as the acyl acceptor and oleoyl-CoA as the acyl donor, 97-98% of the diacylglycerol product was 1,2(2,3)-dioleoyl-sn-glycerol, 90% of which was the sn-1,2- and 10% the sn-2,3-enantiomer. The remaining diacylglycerol (less than 3%) was the sn-1,3-isomer. The overall yield of acylation products was 70%, of which 60% were diacylglycerols and 40% triacylglycerols. With 2-oleylglycerol ether as the acyl acceptor and [1-14C]oleoyl-CoA as the acyl donor, 90% of the diradylglycerol was 1-oleoyl-2-oleyl-sn-glycerol and 10% was the 2-oleyl-3-oleoyl-sn-glycerol. The diradylglycerols made up 96% and the triradylglycerols 4% of the radioactive product. With 1-palmitoyl-sn-glycerol as the acyl acceptor and [1-14C]oleoyl-CoA as the acyl donor, the predominant reaction product was 1-palmitoyl-3-oleoyl-sn-glycerol. The 3-palmitoyl-sn-glycerol was not a suitable acyl acceptor. Both 1,2- and 2,3-diacyl-sn-glycerols were substrates for diacylglycerol acyltransferase as neither isomer was favored when 1,2-dioleoyl-rac-[2-3H]glycerol was used as the acyl acceptor. There was a marked decrease in the acylation of the 1(3)-oleoyl-2-oleyl-sn-glycerol to the 1,3-dioleoyl-2-oleyl-sn-glycerol. It is concluded that neither monoacylglycerol nor diacylglycerol acyltransferase exhibit absolute stereospecificity for acylglycerols as fatty acid acceptors.

[Antitumor effect of liposome-entrapped carboplatin after intraperitoneal administration in rats]

We examined the distribution in tissue and antitumor effects of freeze-dried liposome-entrapped carboplatin (Lipo-CBDCA) after intraperitoneal administration to rats bearing AH 130 tumors. Liposomes composed of egg lecithin and cholesterol were used as drug carriers. The serum concentration of platinum was decreased for a short time after the intraperitoneal administration of Lipo-CBDCA. After at least 3 hours, the serum concentration of platinum was higher with free CBDCA intraperitoneal or intravenous administration. The antitumor effects of Lipo-CBDCA were determined in rats with peritoneal dissemination due to AH 130 tumors. Intraperitoneal Lipo-CBDCA prolonged the life span of the tumor-bearing rats. No side effects of the chemotherapy were demonstrated in biochemical and histological studies in the liver, kidney, spleen and small intestine. These results indicate that intraperitoneal chemotherapy with Lipo-CBDCA may be more effective than that with free CBDCA managing in peritoneal dissemination, and may be therapeutically useful without toxic side effects.

[Efficacy of preoperative adjuvant chemotherapy using adriamycin targeting the regional lymph nodes for gastric cancer--lymph node-targeting delivery of adriamycin in rabbits]

Chemotherapy targeting the regional lymph nodes for gastric cancer may be more effective preoperatively than postoperatively since anticancer drugs can be transported to the regional lymph nodes via the lymphatic flow through the stomach. Distribution of Adriamycin (ADR) among the various organs was assessed following its intravenous injection in rabbits. The delivery index of the drug to each organ was assessed by the ratio of the area under the concentration-time curve (AUC) of each organ to the AUC of the regional lymph nodes following the intravenous administration. The delivery index was 0.14 for the stomach, 0.11 for the heart, 0.53 for bone marrow, 0.74 for the spleen, and 0.14 for the liver. These data suggest that preoperative adjuvant chemotherapy by intravenous administration of ADR may be effective in targeting ADR at the regional lymph nodes. Tissue ADR concentrations in the regional lymph nodes were assessed following gastric submucosal administration of ADR in rabbits. The targeting index for the regional lymph nodes was 8.20, measured by the ratio of AUC following a gastric submucosal injection to AUC after the intravenous injection of ADR. This suggests that it may be possible to selectively target chemotherapy to regional lymph nodes by employing a gastric submucosal administration of ADR.

[Endoscopic injection of liposomal adriamycin targeting lymph node metastasis of gastric cancer]

Gastric submucosal injection of 5 mg liposomal adriamycin (L-ADM) close to the main gastric cancer tumor was done in 15 patients by endoscopy. This approach was based on the idea that preoperative adjuvant chemotherapy targeting lymph node metastasis in patients with gastric cancer may be effective for prevention of lymph node recurrence. ADM concentrations in the regional lymph nodes were assessed and compared with those in patients who were administered 5 mg of free adriamycin (F-ADM) i.v. preoperatively. ADM concentrations in Group 7 lymph nodes (according to the General Rules for Gastric Cancer Study) were: After 2 days; 7.21 +/- 5.98 micrograms/g (n = 2) in the L-ADM group and 0.59 +/- 0.23 micrograms/g (n = 3) in the F-ADM group. After 4 days; 4.93 +/- 3.93 micrograms/g (n = 2) in the L-ADM group and 0.36 +/- 0.0 micrograms/g (n = 2) in the F-ADM group. After 6 days; 2.08 +/- 0.49 micrograms/g (n = 2) in the L-ADM group and 0.05 +/- 0.05 micrograms/g (n = 3) in the F-ADM group. L-ADM group: those who had L-ADM injected into the side of the lesser curvature of the stomach. F-ADM group: those who had F-ADM administered i.v. These data demonstrate that gastric submucosal injection of L-ADM is well suited for specific delivery to the regional lymph nodes, suggesting that this type of administration may prevent lymph node recurrence of gastric cancer by targeting lymph node metastasis.

[Clinical application of chemotherapy via the portal vein with liposome-encapsulated adriamycin in inoperable metastatic liver cancer]

We studied the effects of liposome-entrapped adriamycin (L-ADM) administered via the portal vein and the clinical application of this treatment in the therapy and inhibition of liver metastasis, experimentally and clinically. Liposomes composed of egg phosphatidylcholine (cholesterol 50 mol%) were used as drug carriers. We examined the distribution in tissues and antitumor effect of freeze-dried L-ADM administered via the portal vein to rabbits bearing VX2 tumors. The liver concentration of ADM increased after delivery and cardiac uptake decreased compared with free drug treatment. The life span was prolonged by L-ADM treatment compared with the control group and the free ADM group. This L-ADM administration was confirmed to be safe and revealed a decrease in the heart toxicities compared with free adriamycin. Nineteen cases were studied from Jan. 1986 to May 1991 via the portal vein and the clinical effects were evaluated. From Mar. 1988 to date, 10 cases were treated with L-ADM (20-30 mg every 2 weeks/body) in patients with inoperable cases using subcutaneously implanted reservoir. The median survival was 450 days; 275 days for colon cancer, 492 days for gastric cancer, and 1,052 days for uterine cancer (range: 136-1,152 days), compared with 141 days (range: 52-253 days) in 9 cases of historical control treated with free-ADM via the portal vein. These results suggest that chemotherapy via the portal vein with L-ADM for metastatic liver cancer may increase survival time.

Determination of molecular species of enantiomeric diacylglycerols by chiral phase high performance liquid chromatography and polar capillary gas-liquid chromatography

A simple method is described for the determination of molecular species of enantiomeric sn-1,2- and sn-2,3-diacylglycerols derived from natural triacylglycerols by Grignard degradation. The method is based on a preparative separation of the enantiomeric diacylglycerols as 3,5-dinitrophenylurethane (DNPU) derivatives by high performance liquid chromatography (HPLC) on a chiral column (25 cm x 4.6 mm ID) containing R-(+)-1-(1-naphthyl)ethylamine as a stationary phase. This is followed by polar capillary gas-liquid chromatography (GLC) of the trimethylsilyl (TMS) ether derivatives of the enantiomeric diacylglycerols derived from the DNPU derivatives using trichlorosilane, which does not cause acyl migration and racemization during the reaction. The cleavage is better than 94% complete. The method was standardized with synthetic sn-1,2- and sn-2,3-dipalmitoyl- and rac-1,2-dioleoylglycerols and was applied to the identification and quantitation of individual molecular species of enantiomeric diacylglycerols generated by Grignard degradation of the triacylglycerols from corn oil, cocoa butter, and lard.

HPLC resolution of diacylglycerol moieties of natural triacylglycerols on a chiral phase consisting of bonded (R)-(+)-1-(1-naphthyl)ethylamine

Chiral phase high performance liquid chromatographic resolution of sn-1,2(2,3)- and X-1,3-diacylglycerols generated by partial Grignard degradation from natural triacylglycerols was carried out using a chiral column (25 cm x 4.6 mm i.d.) containing (R)-(+)-1-(1-napthyl)ethylamine polymer chemically bonded to 300A wide pore spherical silica (5 microns particles). The diacylglycerols were chromatographed as 3,5-dinitrophenyl-urethanes and detected at 226 or 254 nm UV. By an isocratic elution with n-hexane- 1,2-dichloroethane-ethanol 40:10:1 (v/v/v) as the mobile phase, the sn-1,2(2,3)-diacylglycerols from corn, linseed, and menhaden oils were resolved into two clearly distinguishable enantiomer groups, although some peak overlappings between the enantiomers were observed in the linseed and menhaden oil diacylglycerols. In addition to the excellent enantiomer resolution, each enantiomer and the X-1,3-isomers were partially resolved into several peaks, which could be tentatively identified on the basis of equivalent carbon number. It is concluded that chiral phase high performance liquid chromatography can be utilized for effective resolution, identification, and quantitation of enantiomeric diacylglycerols from complex natural mixtures.

Rapid separations of diacyl- and dialkylglycerol enantiomers by high performance liquid chromatography on a chiral stationary phase

Rapid and practical separations of 1,2- and 2,3-diacyl- and dialkyl-sn-glycerol enantiomers as their 3,5-dinitrophenyl-urethane derivatives were carried out by normal-phase high performance liquid chromatography on a chiral stationary phase, N-(R)-1-(alpha-naphthyl)ethylaminocarbonyl-(S)-valine chemically bonded to gamma-aminopropyl silanized silica. Complete separations of the racemates into enantiomers were achieved for both of the diacyl- and dialkylglycerols within 10 min using a stainless steel column (25 cm long) packed with the 5-mu particles, an isocratic elution with a mixture of hexane/ethylene dichloride/ethanol as a mobile phase and a UV detector. The sn-1,2-enantiomers were eluted ahead of the corresponding sn-2,3-enantiomers. Satisfactory separation of the sn-1,3-diacylglycerols from the corresponding enantiomers and the separation of the homologues differing in acyl and alkyl groups were also observed. The formations of hydrogen bonding and charge transfer complex between the urethane derivatives and the stationary phase may contribute to the enantiomer separations.

Fatty acids and fatty alcohols of wax esters in the orange roughy: specific textures of minor polyunsaturated and branched-chain components

Open-tubular gas chromatography was carried out on fatty acids and alcohols obtained from wax esters of the orange roughy, Hoplostethus atlanticus, caught at sea off New Zealand. The major (above 5%) components were 16:1(n-7), 18:1(n-9) and (n-7), 20:1(n-9) and (n-7), and 22:1(n-11, n-13) as fatty acids, and 16:0, 18:0, 18:1(n-9), 20:1(n-9) and (n-7), and 22:1(n-11, n-13) as fatty alcohols. The total percentages of the minor components were 10% in the acids and 26% in the alcohols. The 22:1/20:1 ratio of the fatty alcohols obtained in this study was less than 1.0, although the ratio for the Atlantic orange roughy has been reported as being greater than 1.0. The contents of polyenes were as low as 2.48% in the acids and 0.95% in the alcohols, but their compositions showed some specific features. The percentages of the C16-C22 dienes in the total polyenes were remarkably high, 57.7% of these acids and 53.1% of these alcohols. The most important dienes were 18:2(n-6) in the acids and 20:2(n-6) in the alcohols.

Occurrence of plant sterols in aquatic vertebrates

Plant sterols were found by gas liquid chromatography in the sterols of five species of aquatic vertebrates; mackerel (Scomber japonicus), rainbow trout (Salmo gairdnerii), smelt (Osmerus dentex), sardine (Sardinops melanosticta) and chimera (Chimera phantasma). The sterols of chimera liver, sardine flesh and sardine viscera contained 9.0, 2.4 and 3.1% of C28 and C29 sterols in addition to 86.7, 96.6 and 95.2% of cholesterol. The occurrence of norcholestandienol, campesterol, beta-sitosterol and C28 stanol was shown by combined gas chromatography-mass spectrometry. Sperm whale (Physeter catodon) sterols consisted of more than 99% cholesterol with only traces of 22-dehydrocholesterol.

Gas chromatographic resolution of polyunsaturated wax esters based on their degree of unsaturation on Silar 10C

Wax esters of C28-C44 chain-lengths, and containing 0-7 double bonds, were characterized with equivalent chain lengths [ECL] obtained by GC using a cyanosiloxane, Silar 10C. The ECL of the unsaturated wax esters is significantly dependent upon the column temperature, and selection of an appropriate column temperature permitted adequate resolution of critical pairs differing in the degree of unsaturation or the position of the double bonds.

Gas chromatographic separation of cholesteryl esters of fatty acids of different degrees of unsaturation

Cholesteryl esters prepared from the fatty acid methyl esters of linseed oil, pig liver lipids, and Japanese anchory oil have been separated on the basis of their chain lengths and number of double bonds by gas liquid chromatography on a cyanosiloxane SILAR 10C column. The equivalent chain lengths of cholesteryl esters having acyl groups with 14-22 carbons and 0-6 double bonds are presented. A significant influence of the column temperature on the equivalent chain lengths of the polyenoic fatty acid cholesteryl esters has been found. Separation of the cholestanyl and epicholestanyl esters of linseed oil fatty acids, respectively, under the same conditions is also described.