Inhibition of the CDK9-cyclin T1 protein-protein interaction as a new approach against triple-negative breast cancer

Cyclin-dependent kinase 9 (CDK9) activity is correlated with worse outcomes of triple-negative breast cancer (TNBC) patients. The heterodimer between CDK9 with cyclin T1 is essential for maintaining the active state of the kinase and targeting this protein–protein interaction (PPI) may offer promising avenues for selective CDK9 inhibition. Herein, we designed and generated a library of metal complexes bearing the 7-chloro-2-phenylquinoline CˆN ligand and tested their activity against the CDK9–cyclin T1 PPI. Complex 1 bound to CDK9 via an enthalpically-driven binding mode, leading to disruption of the CDK9–cyclin T1 interaction in vitro and in cellulo. Importantly, complex 1 showed promising anti-metastatic activity against TNBC allografts in mice and was comparably active compared to cisplatin. To our knowledge, 1 is the first CDK9–cyclin T1 PPI inhibitor with anti-metastatic activity against TNBC. Complex 1 could serve as a new platform for the future design of more efficacious kinase inhibitors against cancer, including TNBC.

Time-Resolved Luminescent High-Throughput Screening Platform for Lysosomotropic Compounds in Living Cells

Lysosomes are membrane-bound organelles that regulate protein degradation and cellular organelle recycling. Homeostatic alteration by lysosomotropic compounds has been suggested as a potential approach for the treatment of cancer. However, because of the high false-negative rate resulting from strong fluorescent background noise, few luminescent high-throughput screening methods for lysosomotropic compounds have been developed for cancer therapy. Imidazole is a five-membered heterocycle that can act within the acidic interior of lysosomes. To develop an efficient lysosomotropic compound screening system, we introduced an imidazole group to iridium-based complexes and designed a long-lifetime lysosomal probe to monitor lysosomal activity in living cells. By integrating time-resolved emission spectroscopy (TRES) with the novel iridium-based lysosomal probe, a high-throughput screening platform capable of overcoming background fluorescent interference in living cells was developed for discovering lysosomotropic drugs. As a proof-of-concept, 400 FDA/EMA-approved drugs were screened using the TRES system, revealing five compounds as potential lysosomotropic agents. Significantly, the most promising potent lysosomotropic compound (mitoxantrone) identified in this work would have showed less activity if screened using a commercial lysosomal probe because of interference from the intrinsic fluorescence of mitoxantrone. We anticipate that this TRES-based high-throughput screening system could facilitate the development of more lysosomotropic drugs by avoiding false results arising from the intrinsic fluorescence of both bioactive compounds and/or the cell background.

[Influence of comprehensive incubational measures on the perioperative treatment of extensively burned patients who underwent escharectomy and skin grafting]

Objective: To explore the influence of standardized and comprehensive incubational measures on perioperative treatment of extensively burned patients who underwent escharectomy and skin grafting. Methods: From January 2017 to November 2018, 50 patients with extensive burn who underwent escharectomy and skin grafting in the First Affiliated Hospital of Air Force Medical University and met the inclusion criteria of this study, were recruited in this retrospective cohort study. According to the incubational measures at that time, 20 patients (14 males and 6 females, aged (33.5±5.2) years) who received routine incubation during the perioperative period from January to October 2017 were set as routine incubation group, and 30 patients (23 males and 7 females, aged (35.8±1.4) years) who received standardized comprehensive incubational measures during the perioperative period from November 2017 to November 2018 were set as comprehensive incubation group. Their body temperature was controlled mainly in 4 stages: preoperative preparation and transfer from intensive care unit (ICU) to operating room, preoperative preparation in operating room, intraoperative operating room management, as well as postoperative transfer from operating room to ICU. The initial body temperature in operating room and intraoperative hypothermia duration, intraoperative blood loss, postoperative recovery time, postoperative chill, blister, and ulcer, and wound healing rate on post operation day (POD) 10 were recorded and calculated. Data were statistically analyzed with two independent samples t test and chi-square test. Results: (1) The initial body temperature in operating room of patients in comprehensive incubation group was (36.3±0.4) ℃, which was significantly higher than (35.6±0.4)℃ in routine incubation group, t=6.658, P<0.01; the intraoperative duration of hypothermia was (205±38) min, which was significantly shorter than (234±42) min in routine incubation group, t=2.564, P<0.05. (2) The intraoperative blood loss of patients in comprehensive incubation group was (323±114) mL, which was significantly less than (490±162) mL in routine incubation group, t=4.272, P<0.01; the postoperative recovery time was (36±8) min, which was significantly shorter than (49±17) min in routine incubation group, t=3.229, P<0.01. (3) The incidence of postoperative chill of patients in comprehensive incubation group was significantly lower than that in routine incubation group (χ(2)=28.626, P<0.01). The incidences of postoperative blister and ulcer of patients between the 2 groups were close. (4) On POD 10, the wound healing rate of patients in comprehensive incubation group was (78.08±0.06)%, which was significantly higher than (71.03±0.08)% in routine incubation group, t=3.694, P<0.01. Conclusions: The standardized and comprehensive incubational measures can effectively improve the initial body temperature of patients entering the operating room, shorten the intraoperative duration of hypothermia, reduce the amount of blood loss and postoperative complications, as well as shorten the postoperative recovery time, thus improve the wound healing rate.

The design and development of covalent protein-protein interaction inhibitors for cancer treatment

Protein-protein interactions (PPIs) are central to a variety of biological processes, and their dysfunction is implicated in the pathogenesis of a range of human diseases, including cancer. Hence, the inhibition of PPIs has attracted significant attention in drug discovery. Covalent inhibitors have been reported to achieve high efficiency through forming covalent bonds with cysteine or other nucleophilic residues in the target protein. Evidence suggests that there is a reduced risk for the development of drug resistance against covalent drugs, which is a major challenge in areas such as oncology and infectious diseases. Recent improvements in structural biology and chemical reactivity have enabled the design and development of potent and selective covalent PPI inhibitors. In this review, we will highlight the design and development of therapeutic agents targeting PPIs for cancer therapy.

[Exploring of a prognostic long non-coding RNA signature of hepatocellular carcinoma by using public database]

Objective: To explore an effective long non-coding RNA (lncRNA) signature in predicting the prognosis of hepatocellular carcinoma through the analysis on RNA sequencing data of hepatocellular carcinoma patients and peritumoral tissues in the Cancer Genome Atlas (TCGA) database. Methods: The clinical characteristics and RNA sequencing data of 377 hepatocellular carcinoma patients were obtained from TCGA database by the end of February 2018. Then, differentially expressed lncRNAs between 50 pairs of tumor and peritumoral tissues were explored using student's t-test. Next, a lncRNA signature was established through LASSO Cox regression analysis. All the patients were divided into four groups (<P(25), P(25)-, P(50)-, ≥P(75)) based on the cut-off quartiles signature. Finally, compared with the control group (<P(25)), the hazard ratios (HRs) of three groups (P(25)-, P(50)-, ≥P(75)) were calculated by using Cox regression. The survival outcomes of patients in the four groups were compared to evaluate the capacity of the lncRNA signature model. Results: A total of 951 differentially expressed lncRNAs were identified between tumor and peritumoral tissues. A three-lncRNA signature, including LNCSRLR, MKLN1-AS and ZFPM2-AS1, was established to predict the prognosis of hepatocellular carcinoma patients. The outcome suggested that the death risk of the ≥P(75) group was 1.57 times larger than that of the <P(25) group (95%CI: 1.06-2.31, P<0.05). Conclusion: The three-lncRNA signature, which established by LNCSRLR, MKLN1-AS and ZFPM2-AS1, was significantly associated with the prognosis of hepatocellular carcinoma patients based on TCGA database data.

Development of Natural Product-Conjugated Metal Complexes as Cancer Therapies

Platinum-based drugs have revolutionized cancer care, but are unfortunately associated with various adverse effects. Meanwhile, natural product scaffolds exhibit multifarious bioactivities and serve as an attractive resource for cancer therapy development. Thus, the conjugation of natural product scaffolds to metal complexes becomes an attractive strategy to reduce the severe side effects arising from the use of metal bearing drugs. This review aims to highlight the recent examples of natural product-conjugated metal complexes as cancer therapies with enhanced selectivity and efficacy. We discuss the mechanisms and features of different conjugate complexes and present an outlook and perspective for the future of this field.

Evaluation of methanogenic treatment of TMAH (tetra-methyl ammonium hydroxide) in a full-scale TFT-LCD wastewater treatment process

This study evaluated TMAH biodegradation under methanogenic conditions. Under methanogenic conditions, a sludge from a full-scale UASB treating TFT-LCD wastewater was able to degrade 2,000 mg/L of TMAH within 10 h and attained a specific degradation rate of 19.2 mgTMAH/gVSS-h. Furthermore, several chemicals including some surfactants, DMSO, and sulfate were examined for their potential inhibitory effects on TMAH biodegradation under methanogenic conditions. The results indicated that surfactant S1 (up to 2%) and DMSO (up to 1,000 mg/L) presented negligible inhibitory effects on TMAH degradation, while surfactant S2 (0.2-1%) might inhibit methanogenic reaction without any TMAH degradation for 3-5 h. At sulfate concentrations higher than 300 mg/L, a complete inhibition of methanogenic reaction and TMAH biodegradation was observed. Results from cloning and sequencing of archaeal 16S rRNA gene fragments showed that Methanosarcina barkeri and Methanosarcina mazei were the dominant methanogens in the UASB treating TMAH-containing TFT-LCD wastewater.

Microbial ecology and performance of ammonia oxidizing bacteria (AOB) in biological processes treating petrochemical wastewater with high strength of ammonia: effect of Na(2)CO(3) addition

This study evaluated nitrification performance and microbial ecology of AOB in a full-scale biological process, powder activated carbon treatment (PACT), and a pilot-scale biological process, moving bed biofilm reactor (MBBR), treating wastewater collected from a petrochemical industry park. The petrochemical influent wastewater characteristics showed a relative low carbon to nitrogen ratio around 1 with average COD and ammonia concentrations of 310 mg/L and 325 mg-N/L, respectively. The average nitrification efficiency of the full-scale PACT process was around 11% during this study. For the pilot-scale MBBR, the average nitrification efficiency was 24% during the Run I operation mode, which provided a slightly better performance in nitrification than that of the PACT process. During the Run II operation, the pH control mode was switched from addition of NaOH to Na(2)CO(3), leading to a significant improvement in nitrification efficiency of 51%. In addition to a dramatic change in nitrification performance, the microbial ecology of AOB, monitored with the terminal restriction fragment length polymorphism (T-RFLP) molecular methodology, was found to be different between Runs I and II. The amoA-based TRFLP results indicated that Nitrosomonas europaea lineage was the dominant AOB population during Run I operation, while Nitrosospira-like AOB was dominant during Run II operation. To confirm the effects of Na(2)CO(3) addition on the nitrification performance and AOB microbial ecology observed in the MBBR process, batch experiments were conducted. The results suggest that addition of Na(2)CO(3) as a pH control strategy can improve nitrification performance and also influence AOB microbial ecology as well. Although the exact mechanisms are not clear at this time, the results showing the effects of adding different buffering chemicals such as NaOH or Na(2)CO(3) on AOB populations have never been demonstrated until this study.

Microbial ecology and performance of nitrifying bacteria in an aerobic membrane bioreactor treating thin-film transistor liquid crystal display wastewater

This study was conducted to evaluate the long-term performance of an aerobic membrane bioreactor (MBR), treating TFT-LCD wastewater containing dimethyl sulphoxide (DMSO), monoethanolamine (MEA) and tetra-methyl ammonium hydroxide (TMAH), which are recognized as slow-biodegradable organic compounds containing nitrogen and can release significant amount of ammonia during biodegradation. Moreover, many studies have reported that certain organic compounds can potentially inhibit nitrification of AOB, but limited information is available regarding the effects of TFT-LCD wastewater compounds on nitrification performance and microbial ecology of nitrifying bacteria. In general, the aerobic MBR achieved satisfactory conversion efficiency for DMSO, MEA, TMAH, and ammonia, except that a sudden inhibition on MEA degradation was observed for a transition period when the influent feed switched from synthetic to real TFT-LCD wastewater. Furthermore, the terminal restriction fragment length polymorphism (T-RFLP) methodology was applied to monitor the microbial ecology of nitrifying bacteria in the aerobic MBR. The results suggested that Nm. marina or Nm. cummunis were the dominant AOB population in the aerobic MBR fed with synthetic TFT-LCD wastewater, while Nitrosospira became dominant in the aerobic MBR fed with real TFT-LCD wastewater. For the NOB population, both Nitrobacter and Nitrospira were present during this study. Finally, the results of batch experiments, which were conducted to evaluate the effects of DMSO, MEA, and TMAH on nitrification activity, indicated that MEA and TMAH became inhibitory to nitrifying bacteria at concentrations of 250 and 50 mg/L, respectively, while DMSO did not at concentrations up to 100 mg/L.

Evaluation of performance and microbial ecology of sequencing batch reactor and membrane bioreactor treating thin-film transistor liquid crystal display wastewater

In Taiwan, a substantial amount of thin-film transistor liquid crystal display (TFT-LCD) wastewater is produced daily due to an increasing production of the opto-electronic industry in recent years. The main components of TFT-LCD wastewater include dimethyl sulphoxide (DMSO), monoethanolamine (MEA), and tetra-methyl ammonium hydroxide (TMAH), which are recognized as non-or slow-biodegradable organic compounds and limited information is available regarding their biological treatablility. This study was conducted to evaluate the long-term performance of two bioreactors, anaerobic-aerobic (A/O) sequencing batch reactor (SBR) and aerobic membrane bioreactor (MBR), treating synthetic TFT-LCD wastewater containing DMSO, MEA, and TMAH with different loadings. For the A/O SBR, the influent wastewater was composed of 800 mg MEA/L, 430 mg DMSO/L, and 90 mg TMAH/L, respectively. After reaching steady-state, SBR was able to achieve more than 99% degradation efficiencies for the three compounds examined. For the case of aerobic MBR, the influent wastewater was composed of 550 mg MEA/L, 270 mg DMSO/L, and 330 mg TMAH/L, respectively, and degradation efficiencies for the three compounds achieved more than 99%. Although both different reactors shared similar and satisfactory degradation efficiencies for DMSO, MEA, and TMAH, the microbial ecology of these two reactors, as elucidated with molecular methods, was apparently different. The 16S rDNA-based cloning/sequencing results indicated that the dominant sequences retrieved from the aerobic MBR, including Hyphomicrobium denitrificans, Hyphomicrobium zavarzinii, Rhodobacter sp., and Methyloversatilis universalis, showed a clear linkage to their physiological properties of DMSO and TMAH degradation. On the other hand, Zoogloea sp., Chlorobium chlorochromatii, Agricultural soil bacterium, and Flavosolibacter ginsengiterrae were proliferated in the A/O SBR Run1, while Thiobacillus sp., Nitrosomonas sp., Thauera aromatica and Azoarcus sp. became dominant in Run2. Furthermore, the sequences retrieved from different reactors were used to establish the terminal restriction fragment length polymorphism (TRFLP) fingerprint methodology for monitoring the dynamics of dominant degrading bacteria in the aerobic MBR treating TFT-LCD wastewater.

Study of a three-stage fluidized bed process treating acrylic synthetic-fiber manufacturing wastewater containing high-strength nitrogenous compounds

Polyacrylonitrile (PAN) is one of the major synthetic fibers commonly used in the mass production of clothing. The chemical synthesis of PAN is carried out by polymerization of the acrylonitrile (AN) monomers with co-monomers such as vinyl acetate, methyl acrylate and cyclohexyl acrylate. Using water quality analysis of the PAN wastewater, high concentration of organic nitrogen was found and the TKN/COD ratios achieved were 0.15-0.26, indicating the complicated biodegradation characteristics for the PAN wastewater. In order to enhance biodegradation of nitrogenous compounds in PAN wastewater, a combined three-stage process of thermophilic anaerobic/anoxic denitrification/aerobic nitrification fluidized bed reactors was employed. The results indicated that the concentration of effluent in the three-stage process of OD and organic nitrogen was 175 mg/L and 13 mg/L, respectively. Furthermore, molecular biotechnology was applied to study the microbial population in the thermophilic anaerobic fluidized bed reactor. From the results of denaturing gradient gel electrophoresis, the diversity of PAN-degrading bacteria would change in different volumetric loading. Furthermore, the bacteria communities in the thermophilic anaerobic fluidized bed reactor were also studied by fluorescence in situ hybridization and confocal laser scanning microscopy. Alpha and delta-Proteobacteria were dominant in the bacteria population, and some high G+C content bacteria and Clostridium could be characterized in this system.

Effects of substrate components on hydrogen fermentation of multiple substrates

As is well known, carbohydrate is the most appropriate organic material for hydrogen fermentation, and its hydrogen yield is significantly larger than that of protein. The fermentation of protein began with hydrogen production followed by hydrogen consumption, which helps overall hydrogen recovery. Both carbohydrate and protein are basic components of organic material, and yet carbohydrate is known to be a better substrate than protein in terms of hydrogen yield during hydrogen fermentation. This study used multiple substrates containing different ratios of glucose and peptone as multiple substrates to investigate the roles played by carbohydrate and protein in hydrogen fermentation. The experimental results demonstrated that suitable ratios of glucose and peptone improved the growth of hydrogen producing bacteria. Additionally, a maximum hydrogen yield of 6.4 mmole-H2/g-COD was obtained from the multiple substrate containing 40% peptone and 60% glucose. Most of the produced hydrogen came from fermentation of glucose, not peptone. During hydrogen fermentation, the pH dropped by 1.0 and 1.9 units in 80% and 20% of peptone content in the substrate. Ammonia produced due to peptone degradation neutralized the acids produced from hydrogen fermentation.

Effects of volatile fatty acids on a thermophilic anaerobic hydrogen fermentation process degrading peptone

Hydrogen fermentation using glucose as a single substrate caused abrupt pH drops and the gradual losses of hydrogen producers, which in turn led to system failure. In this study the use of a proteinaceous substrate, peptone, avoided the abrupt pH drops in the reactive system and allowed for further exploration of volatile fatty acids (VFAs) and pH effects on the hydrogen fermentation process. Our results showed that: (1) during the hydrogen fermentation tests, the abrupt pH drops were avoided thus system stability increased due to the production of ammonia from the peptone fermented, (2) pH control was not necessary and the addition of acetate to the process had little effect on the hydrogen fermentation process, (3) at the extreme pHs the addition of acetate either lengthened the lag phase (pH < or = 6) or slowed the hydrogen production rate (pH > or = 8), and both situations were not desired, and (4) high VFA content in the system sped up the consumption of hydrogen gas. Results of this study suggested that the hydrogen fermentation using the protein-containing substances as substrate was beneficial in maintaining the system pH. As long as the pH was maintained around 6-8, system inhibition due to VFAs accumulation was minimized. Thus, the optimal operation of a hydrogen fermentation process would be achievable via the control of substrate composition at a certain carbohydrate-to-protein ratio.

Extrapancreatic pseudoaneurysm after pancreas transplantation

Pseudoaneurysms after pancreatic transplantation are an infrequent event. Repair usually involves removal of the transplant. We describe a patient with a pseudoaneurysm associated with pancreatic transplantation. The pseudoaneurysm originated from the external iliac artery distal to the donor Y-graft anastomosis. Diagnosis was made by duplex ultrasound. Surgical repair was effected through a retroperitoneal incision enabling vascular control. The patient has done well postoperatively, and with 1-year follow-up, continues to have normal renal and pancreatic allograft function.

Antitermitic activity of essential oils and components from Taiwania (Taiwania cryptomerioides)

Antitermitic activity of Taiwania (Taiwania cryptomerioides Hayata) against Coptotermes formosanus Shiraki was demonstrated in laboratory tests. Blocks of sapwood and heartwood from T. cryptomerioides exhibited antitermitic activity. Bioassays revealed that heartwood essential oil exhibited the highest antitermitic activity, followed by sapwood essential oil and then the n-C6H14 soluble fraction when tested at 10 mg/g. The order of termite mortality of three compounds purified from n-C6H14 soluble extracts of heartwood was cedrol > alpha-cadinol > ferruginol. The termite resistance of T. cryptomerioides wood can be attributed to the termiticidal activity of cedrol and alpha-cadinol.

Granulocyte-macrophage colony stimulating factor up-regulates CCR1 in human neutrophils

Neutrophils (polymorphonuclear leukocytes; PMN) are phagocytic cells instrumental in the clearance of infectious pathogens. Human PMN are commonly thought to respond primarily to chemokines from the CXC family. However, recent findings suggest that under specific cytokine activation conditions, PMN can also respond to some CC chemokines. In this study, the effect of GM-CSF, a well-characterized PMN priming and maturation factor, on CC-chemokine receptor (CCR) expression in PMN was investigated. Constitutive expression of CCR1 and CCR3 mRNA in PMN was detected by ribonuclease protection assay. Following incubation of PMN with GM-CSF (0.01-10 ng/ml; 6 h) CCR1 mRNA expression was rapidly (approximately 1 h) up-regulated. In contrast, no significant induction of CCR2, CCR3, CCR4, or CCR5 mRNA was observed. CCR1 protein was also up-regulated by GM-CSF stimulation. GM-CSF-induced up-regulation of CCR1 showed functional consequences because GM-CSF-treated PMN, but not control cells, responded to the CC chemokines macrophage inflammatory protein-1alpha, monocyte chemoattractant protein-3, and RANTES in assays of chemotactic migration and intracellular calcium mobilization. These results suggest that PMN activated by the proinflammatory cytokine GM-CSF can change their receptor expression pattern and become responsive to CC chemokines.

Utility of CT angiography for evaluation of living kidney donors

We reviewed our initial experience with helical computed tomography (CT) angiography in the evaluation of living kidney donors which, until now, has necessitated arteriography. Nineteen donors (12 women, 7 men) have had their renal anatomy evaluated solely by CT angiography preoperatively. All scans demonstrated normal collecting systems and single ureters. Five donors (26%) had supernumerary renal arteries. Fourteen donors had single, 4 donors had two, and 1 donor had three renal arteries. Helical CT demonstrated small polar vessels in several donors. Two donors (10%) had supernumerary renal veins. Accuracy of vascular anatomy defined on CT was 90% when confirmed at operation. Anatomically all CT findings were consistent with operative findings except in 1 donor who was found to have a 0.8 cm lesion near the renal hilum. At our institution, the total charges for selective renal arteriography are $3845 and for helical CT with three-dimensional (3-D) reconstruction are $1546. The amount of contrast dye (approximately 100 mL) is equivalent. Patients uniformly reported that the CT scan was a convenient and painless procedure. The accuracy of helical CT angiography is equivalent to arteriography in assessing renal vascular anatomy (with the additional benefit of imaging venous and parenchymal anatomy). Charges for helical CT are 59% less. There is greater patient acceptance and potentially less morbidity associated with the non-invasive nature of helical CT. We believe that CT angiography is the radiologic procedure of choice for the assessment of renal anatomy in potential living kidney donors.

Predictors of progression of diabetic nephropathy: implication for timing of kidney transplantation

Multiple risk factors are important predictors in the development of diabetic nephropathy (DN). Once DN has developed, it progresses steadily to renal failure. To determine the rate of renal function decline and the parameters that influence the rate of decline, we retrospectively reviewed the charts of patients with DN who had undergone dialysis or kidney transplantation at the Mayo Clinic from 1983 to 1993. Forty patients were found to have two or more iothalamate clearance (IothmCl) measurements where a slope of renal function decline over time, expressed as mL/ min/month/1.73 m2, can be calculated. The parameters examined included age of onset and duration of diabetes (DM); age at initial presentation, insulin dosage, glycosylated hemoglobin level, proteinuria, blood pressure (BP), number of antihypertensive medications (HTM), use of ACE inhibitors, creatinine, and initial IothmCl. The mean overall decline of clearance was 1.36 +/- 1.1 mL/min/month, corrected. Univariate regression analysis showed that only systolic and mean BP (p < 0.05), use of HTM (p = 0.02), and the number of HTM used (p = 0.0001) correlated with the rate of clearance decline. No other parameter was significant. The decline of IothmCl was 0.72 +/- 0.41, 1.20 +/- 0.9, and 2.34 +/- 1.38 mL/min/month, for patients taking no HTM, < 3 HTM, and > or = 3HTM, respectively. Of the eight patients on HTM who presented with initial IothmCl of < 30 mL/min/1.73 m2, seven (88%) had clearance of < 10 mL/min/1.73 m2 within 1 yr. We conclude that hypertension is an important marker of DN progression, and that the more HTM required for control of BP, the faster the decline of renal function. We recommend that a suitable transplant candidate with DN who presents with hypertension requiring HTM and a clearance of < 30 mL/min should be placed on the transplant waiting list.

Liver transplantation: perspectives after 250 liver transplants at the Ochsner Clinic

At the Ochsner Clinic we recently performed our 250th liver transplant. Reaching this milestone has led us to reflect back on the history of liver transplant, both at our own institution and nationally, noting the many achievements and improvements in liver transplantation during the relatively brief history of this therapeutic modality. Furthermore, there are a number of issues both medical and political which will likely be affecting how liver transplantation is performed in the future.

Massive loss of mid- and hindbrain neurons during embryonic development of homozygous lurcher mice

The mouse neurological mutant lurcher (Lc) results from a semidominant mutation. Heterozygous Lc/+ mice are viable but ataxic because Lc/+ Purkinje cells die by apoptosis within the first 3 weeks of life. Lc/Lc mice die shortly after birth. To aid in understanding the function of the lurcher gene product, we have examined the embryonic development of homozygous lurcher animals. The ratio of +/+:Lc/+:Lc/Lc animals did not deviate significantly from the expected 1:2:1. Homozygous lurcher mice at P0 were found to be normal under gross morphological examination. However, these mice weighed less, lacked milk in their stomach, and died within the first day of life. No resorbed embryos were found at embryonic day (E) 17.5, indicating that all homozygous lurchers survived until birth. Histological examination of P0 animals revealed that in homozygous lurcher mice the patterning of the brain is normal but that there has been a massive loss of hindbrain neurons during embryonic development. A particularly conspicuous consequence of the Lc/Lc genotype at birth is the complete absence of large neurons comprising the trigeminal motor nucleus. These neurons arise normally and are maintained until E15.5. However, beginning at E15.5 large numbers of pyknotic cells are evident in the trigeminal motor nucleus, suggesting that these cells die coincident with their terminal differentiation in the developing hindbrain. Because the trigeminal motor nucleus controls muscles required for suckling, these results suggest an explanation for the neonatal death of homozygous Lc animals. These data demonstrate that the severe and dose-dependent developmental consequences of lurcher gene action result from degeneration of distinct neuronal populations on maturation in the developing CNS.

The lurcher gene induces apoptotic death in cerebellar Purkinje cells

In the neurologically mutant mouse strain lurcher (Lc), heterozygous animals display cell autonomous degeneration of cerebellar Purkinje cells beginning in the second postnatal week. During the course of our studies to identify the genetic lesion responsible for this disease (Norman et al., 1991), we have formulated an hypothesis suggesting that in Lc Purkinje cells homeostasis is sufficiently perturbed to lead to the activation of programmed cell death, thus resulting in neuronal loss and the consequent neurologic disease (Heintz, 1993). To address this possibility, we have examined the properties of Lc Purkinje cells as they die during the second postnatal week. Our light and electron microscopic studies demonstrate that dying Lc Purkinje cells exhibit the characteristic morphologic features of apoptosis, including nuclear condensation, axon beading and membrane blebbing. Using an in situ end-labeling method, we have also detected nicked nuclear DNA in these cells. Furthermore, we have examined the expression of the sulfated glycoprotein 2 (SGP2), whose mRNA is induced in both T-cells and prostate epithelial cells undergoing apoptotic death. We show by in situ hybridization that SGP2 is not expressed at detectable levels in normal Purkinje cells, but that its mRNA is present in Lc Purkinje cells prior to their death. Also expression of the Kv3.3b potassium channel, which marks the terminal phase of Purkinje cell differentiation, is evident in Lc Purkinje cells prior to their death. These data demonstrate that the Lc mutation induces apoptosis in cerebellar Purkinje cells following their maturation in postnatal cerebellum. Isolation of the Lc mutation and further analysis of its action in eliciting apoptosis can provide an important opportunity for understanding the etiology of neurodegenerative disease.

Early irradiation effects observed on magnetic resonance imaging and angiography, and positron emission tomography for arteriovenous malformations treated by Gamma Knife radiosurgery

In 14 patients (7 males and 7 females, age 16-49, mean 29 years), medium-to-large arteriovenous malformations (AVMs; nidus volume 3.5-17.5 cm3, mean 9.4 cm3) were treated by Gamma Knife radiosurgery. Stereotactic MR and conventional angiography were included for targeting to improve targeting accuracy and tissue content in the irradiation volume. Maximum irradiation doses to the nidi were 36-40 Gy (mean 38.9 Gy) and minimum target doses were 18-24 Gy (mean 20 Gy). MR images and MR angiography demonstrated decreasing caliber of feeding vessels and AVM nidus volumes from an early stage, 3 months after radiosurgery, which indicated improvement in cerebral hemodynamics. The improvement correlated well with that observed on PET using [18F]fluorodeoxyglucose (FDG) and with the patients' clinical condition. MR creates an opportunity to monitor treatment effects in a completely noninvasive manner, while conventional angiography remains necessary for verifying complete obliteration of AVMs. More patients and longer follow-ups are needed for clarifying the role of MR techniques in radiosurgery for AVMs.

Rh phenotypes of Chinese blood donors in Hong Kong, with special reference to weak D antigens

Among Hong Kong Chinese blood donors, 99.71 percent were found to be D+. Of these, 55.02 percent were of the phenotype CCDee. The Du phenotype was found to be present in 0.016 percent. Among the 0.27 percent who were apparently D-, 0.079 percent were of the Del phenotype, while the remaining 0.19 percent were "true D-," as defined by a nonreactive eluate obtained by an adsorption and elution procedure using anti-D. The ccdee phenotype constitutes 56.77 percent of the "apparent D-" and 80.24 percent of the true D-. Data show that anti-D rarely occurs in Hong Kong Chinese, and it is postulated that this could be due to the presence of a very weak form of the D antigen among many of those who appear to be D-.

Morula decompaction (mdn), a preimplantation recessive lethal defect in a transgenic mouse line

The beta S12 transgenic line carries an insertion of exogenous DNA and a deletion of approximately 2 cM on chromosome 1. Transgenic heterozygotes (beta S12/+) were viable and fertile, but homozygous mice (beta S12/beta S12) could not be produced. To determine the stage at which developmental arrest occurred in homozygotes, embryos derived from intercrosses among heterozygotes or from control crosses were examined at various stages. No homozygotes could be detected at postimplantation stages, suggesting that the mutation affected embryogenesis before implantation. Recovery of embryos at 1.5 or 3.5 days postcoitum, followed by culture in vitro, revealed an abnormal class of embryos which constituted one-fourth of the progeny from intercrosses, and thus appeared to represent the beta S12/beta S12 homozygotes. These embryos cleaved normally to the 8-cell stage and formed compacted morulae, but then decompacted without forming a blastocyst, and ceased dividing at approximately the 16-cell stage. Nearly all blastomeres were viable at the time of decompaction, as demonstrated by trypan blue exclusion, indicating that the loss of compaction is not simply a consequence of cell death. When labeled with a short-term lineage marker and aggregated with normal embryos at the early 8-cell stage, homozygous mutant embryos failed to contribute to the resulting blastocysts, indicating that the defect in the maintenance of compaction is cell autonomous. Based on the mutant phenotype, we conclude that this genetic lesion affects a gene (or genes) required for the maintenance of compaction, and propose that it be named morula decompaction (mdn). The phenotype of mdn/mdn embryos appears to be distinct from those caused by other previously described preimplantation lethal mutations or chromosomal deletions.

Primary colorectal lymphoma in Taiwan

BACKGROUND

Sixteen patients with primary lymphoma of the colon and rectum were studied.

METHODS

The median age of these patients was 34 years, and 13 were men. These patients often experienced abdominal pain, diarrhea, a palpable abdominal mass, weight loss, bloody stools, and tumor of the cecum. Intermediate or high-grade lymphomas occurred in 14 patients, and 5 patients had T-cell lesions. The diagnoses were established by using laparotomy in 14 patients and colonoscopic biopsy in 2 patients. Fourteen patients had surgical resections followed by chemotherapy: cyclophosphamide, doxorubicin, vincristine, and prednisolone in 10; cyclophosphamide, vincristine, and prednisolone (COP) in 2; and cyclophosphamide, vincristine, methotrexate, and prednisolone in 1 patient. Two patients underwent biopsy alone followed by chemotherapy with COP in one and chemotherapy with prednisolone in the other.

RESULTS

The median follow-up time was 38 months (range, 2-82 months). Eight patients are alive with no evidence of disease (range, 10-82+ months). Six patients died of disease from 2 to 44 months after diagnosis. One patient who had no evidence of lymphoma died of esophageal carcinoma at 61 months. The median survival time was 59 months.

CONCLUSIONS

The authors' experience with colorectal lymphoma in Taiwan is different from that reported from Japan and other countries. The patients of this study were significantly younger and many had T-cell lesions. Despite the frequently poor histologic types, surgical resection and adjuvant chemotherapy can result in long-term, disease-free survival in many patients with primary colorectal lymphoma.

Effect of donor-disseminated intravascular coagulation in liver transplantation

It is not known whether disseminated intravascular coagulation, present in a large percentage of organ donors, affects patient outcome after liver transplantation. We reviewed our first 55 liver transplantations and identified 10 donors with disseminated intravascular coagulation. We compared the perioperative courses of the 10 recipients of these transplanted livers with those of 10 matched controls whose donors did not have disseminated intravascular coagulation. Disseminated intravascular coagulation recipients did not require more blood products during or after surgery; their hepatic enzyme levels and prothrombin times after surgery were not statistically significantly higher than those of the controls. There was no difference in hospital stay, number of episodes of rejection, retransplantations, or deaths. The presence of disseminated intravascular coagulation in donors did not adversely affect graft function or patient outcome and should not be a sole criterion for rejecting a liver for transplantation.

[Embolization of an arteriovenous fistula in the posterior fossa: report of a case]

We report a case of posterior fossa arteriovenous fistula with a possible arterial aneurysm. The patient was a 15-year-old female. She was transferred to us because of a sudden onset of dyspnea, severe headaches, and loss of consciousness. The CT scan found an abnormal vascular lesion in the posterior fossa. Calcification was noted in the wall of the largest abnormal vascular structure. The angiogram showed a focal aneurysmal dilatation of the hemispheric branch of the right posterior inferior cerebellar artery, followed by an arteriovenous fistula, which drained to the right transverse sinus. Embolization was performed by implanting a detachable balloon into the proximal end of the aneurysm. These abnormal vascular structures disappeared completely on the angiogram after the embolization. CT scan one week after embolization showed increased density in these abnormal vascular structures, with no enhancement after contrast, indicating thrombosis or the formation of a blood clot in their lumen. The CT half a year after embolization showed reduction in size and a low density change in the largest vascular structure with calcification in the wall. All other abnormal vascular structures disappeared. An angiogram half a year after the embolization confirmed no recurrence of the aneurysm or arteriovenous fistula.

[Direct observation of the tympanic cavity by the superfine fiberscope]

As a clinical test, direct observation of the middle ear should be ideally performed without any surgical intervention such as myringotomy. This paper reports a newly invented superfine fiberscope which makes it possible to insert through the eustachian tube, and direct views of the middle ear structures on normal subjects and patients. The patients were of a small cholesteatoma and traumatic dislocation of the ossicular chain. All of them were tested with local anesthesia in outpatient clinic. This superfine fiberscope was of great value in observing of middle ear structures as a diagnostic instruments, as that no surgical intervention was necessary in the procedure.

Inhibition of tail-flick and shaking responses by intrathecal and intraventricular D-Ala2-D-Leu5-enkephalin and beta-endorphin in anesthetized rats

The present study compares the potencies of D-Ala2-D-Leu5-enkephalin (DADL) and beta-endorphin (beta-EP) injection intrathecally and i.c.v. on the inhibition of tail-flick and ice water-induced shaking responses in pentobarbital-anesthetized rats. Peptides were injected stereotaxically into the third ventricle or into the spinal subarachnoid space. The tail-flick response was measured 10 or 20 min after the injection of DADL or beta-EP, respectively, after which the rats were immersed for 5 min in ice water and the number of shakes was counted. Intrathecal DADL and beta-EP were equipotent in inhibiting both the tail-flick and shaking responses. However, treatment with naloxone (2 mg/kg i.p.) shifted the dose-response curve for both responses to the right more for the beta-EP than for DADL. Unlike the equipotency intrathecally, DADL by i.c.v. injection was less potent than beta-EP in inhibiting both the tail-flick and shaking responses. Previous results in the unanesthetized rat had also shown that i.c.v. DADL was less potent than beta-EP in inhibiting the tail-flick response. Thus, the spinal cord is sensitive to both DADL and beta-EP, whereas the supraspinal area is more sensitive to beta-EP. Also, because the potency of i.c.v. beta-EP for inhibiting tail-flick but not shaking was substantially reduced in anesthetized compared to unanesthetized rats, the neuronal substrates involved in inhibition of shaking are different from those of inhibition of the tail-flick. The differential sensitivities to i.c.v. vs. intrathecal administration and the unequal responses to the antagonistic action of naloxone indicate that DADL and beta-EP produce their action through different opioid receptors.