High-Throughput Single Nucleotide Polymorphism (SNP) Discovery and Validation Through Whole-Genome Resequencing in Nile Tilapia (Oreochromis niloticus)

Nile tilapia (Oreochromis niloticus) is the second most important farmed fish in the world and a sustainable source of protein for human consumption. Several genetic improvement programs have been established for this species in the world. Currently, the estimation of genetic merit of breeders is typically based on genealogical and phenotypic information. Genome-wide information can be exploited to efficiently incorporate traits that are difficult to measure into the breeding goal. Thus, single nucleotide polymorphisms (SNPs) are required to investigate phenotype-genotype associations and determine the genomic basis of economically important traits. We performed de novo SNP discovery in three different populations of farmed Nile tilapia. A total of 29.9 million non-redundant SNPs were identified through Illumina (HiSeq 2500) whole-genome resequencing of 326 individual samples. After applying several filtering steps, including removing SNP based on genotype and site quality, presence of Mendelian errors, and non-unique position in the genome, a total of 50,000 high-quality SNPs were selected for the development of a custom Illumina BeadChip SNP panel. These SNPs were highly informative in the three populations analyzed showing between 43,869 (94%) and 46,139 (99%) SNPs in Hardy-Weinberg Equilibrium; 37,843 (76%) and 45,171(90%) SNPs with a minor allele frequency (MAF) higher than 0.05; and 43,450 (87%) and 46,570 (93%) SNPs with a MAF higher than 0.01. The 50K SNP panel developed in the current work will be useful for the dissection of economically relevant traits, enhancing breeding programs through genomic selection, as well as supporting genetic studies in farmed populations of Nile tilapia using dense genome-wide information.

Whole Genome Linkage Disequilibrium and Effective Population Size in a Coho Salmon (Oncorhynchus kisutch) Breeding Population Using a High-Density SNP Array

The estimation of linkage disequilibrium between molecular markers within a population is critical when establishing the minimum number of markers required for association studies, genomic selection, and inferring historical events influencing different populations. This work aimed to evaluate the extent and decay of linkage disequilibrium in a coho salmon breeding population using a high-density SNP array. Linkage disequilibrium was estimated between a total of 93,502 SNPs found in 64 individuals (33 dams and 31 sires) from the breeding population. The markers encompass all 30 coho salmon chromosomes and comprise 1,684.62 Mb of the genome. The average density of markers per chromosome ranged from 48.31 to 66 per 1 Mb. The minor allele frequency averaged 0.26 (with a range from 0.22 to 0.27). The overall average linkage disequilibrium among SNPs pairs measured as r² was 0.10. The Average r² value decreased with increasing physical distance, with values ranging from 0.21 to 0.07 at a distance lower than 1 kb and up to 10 Mb, respectively. An r² threshold of 0.2 was reached at distance of approximately 40 Kb. Chromosomes Okis05, Okis15 and Okis28 showed high levels of linkage disequilibrium (>0.20 at distances lower than 1 Mb). Average r² values were lower than 0.15 for all chromosomes at distances greater than 4 Mb. An effective population size of 43 was estimated for the population 10 generations ago, and 325, for 139 generations ago. Based on the effective number of chromosome segments, we suggest that at least 74,000 SNPs would be necessary for an association mapping study and genomic predictions. Therefore, the SNP panel used allowed us to capture high-resolution information in the farmed coho salmon population. Furthermore, based on the contemporary N_e, a new mate allocation strategy is suggested to increase the effective population size.

Validation of a Simplified SRS-Schwab Classification Using a Sagittal Modifier

STUDY DESIGN

Multicenter, prospective study of consecutive adult spinal deformity (ASD) patients.

OBJECTIVE

To Validate Schwab's classification accuracy for surgical indication, and to evaluate a simplified sagittal modifier.

SUMMARY OF BACKGROUND DATA

The SRS-Schwab Radiologic Classification based on clinical impact parameters, offers 27 different sagittal classification possibilities regarding sagittal vertical alignment (SVA), pelvic tilt (PT), and pelvic incidence-lumbar lordosis (PI-LL). The high number of classification possibilities makes it complex to use.

METHODS

Inclusion criteria were ASD patients, presenting at least 1 criteria: Cobb ≥ 20°, SVA ≥ 5 cm, thoracic kyphosis ≥ 60°, or PT ≥ 25°. A total of 1,004 patients (410 nonoperative and 594 operative) were classified regarding SVA, PT, and PI-LL (0, +, ++), and 27 possibilities were identified. Categories were formed by adding the number of + signs, considering PT, SVA, and PI-LL. Three specific categories were identified: Aligned: 0 +; Moderate deformity: 1 to 3+; and Severe deformity: 4 to 6+. A χ-square test was performed for surgical indication (operated or not) and an analysis of variance was performed to evaluate the relationship between categories and Oswestry Disability Index (ODI). Probability <.05 was considered significant.

RESULTS

Significant differences for HRQoL scores and surgical indication were found in the 27 sagittal parameter possibilities. For nonoperative patients, 230 (56.1%) were classified as aligned, 145 (35.4%) as moderate, and 35 (8.5%) as severe. For operative patients, there were 200 (33.7%), 215 (36.2%), and 179 (30.1%) in each respective subgroup. For HRQoL scores and surgical indication, no significant differences were found within each category, but significant differences were found when comparing the subgroups.

CONCLUSIONS

Despite the correlation between SRS-Schwab classification and surgical indication, it is complex to use, with a total of 27 possibilities regarding sagittal modifiers. This simplification into three categories offers more readability, without losing any significant information, and could replace Schwab sagittal modifiers. In association with other parameters, they could be used for decision-making.

LEVEL OF EVIDENCE

Level II.

Population Genomic Structure and Genome-Wide Linkage Disequilibrium in Farmed Atlantic Salmon (Salmo salar L.) Using Dense SNP Genotypes

Chilean Farmed Atlantic salmon (Salmo salar) populations were established with individuals of both European and North American origins. These populations are expected to be highly genetically differentiated due to evolutionary history and poor gene flow between ancestral populations from different continents. The extent and decay of linkage disequilibrium (LD) among single nucleotide polymorphism (SNP) impacts the implementation of genome-wide association studies and genomic selection and provides relevant information about demographic processes of fish populations. We assessed the population structure and characterized the extent and decay of LD in three Chilean commercial populations of Atlantic salmon with North American (NAM), Scottish (SCO), and Norwegian (NOR) origin. A total of 123 animals were genotyped using a 159 K SNP Axiom® myDesignTM Genotyping Array. A total of 32 K SNP markers, representing the common SNPs along the three populations after quality control were used. The principal component analysis explained 78.9% of the genetic diversity between populations, clearly discriminating between populations of North American and European origin, and also between European populations. NAM had the lowest effective population size, followed by SCO and NOR. Large differences in the LD decay were observed between populations of North American and European origin. An r 2 threshold of 0.2 was estimated for marker pairs separated by 7,800, 64, and 50 kb in the NAM, SCO, and NOR populations, respectively. In this study we show that this SNP panel can be used to detect association between markers and traits of interests and also to capture high-resolution information for genome-enabled predictions. Also, we suggest the feasibility to achieve similar prediction accuracies using a smaller SNP data set for the NAM population, compared with samples with European origin which would need a higher density SNP array.

Isolation and characterization of halophilic lactic acid bacteria acting as a starter culture for sauce fermentation of the red alga Nori (Porphyra yezoensis)

AIMS

A screening test was conducted for environmental samples to isolate halophilic lactic acid bacteria (HLAB) that can act as a starter in a Nori (Porphyra yezoensis)-sauce culture.

METHOD AND RESULTS

After 9 months of incubation of enrichment cultures added with 25 kinds of environmental samples, growth of HLAB-like microorganisms was observed in six cultures salted at a 15% w/w level, including culture samples originally from mesopelagic water taken from 321 m-depth and from mountain snow taken at 2450 m-height. Ten strains were isolated and characterized as Tetragenococcus halophilus based on sequence analysis of the 16S rRNA gene. The isolates were inoculated into a newly prepared Nori-sauce culture and were confirmed to be able to act as a starter culture while three reference strains of T. halophilus obtained from a culture collection could not grow in the same culture.

CONCLUSIONS

Halophilic lactic acid bacteria strains that can make growth in a highly salted Nori-sauce culture were isolated from environmental samples for the first time. All the isolates were identified as T. halophilus.

SIGNIFICANCE AND IMPACT OF THE STUDY

The isolated strains are expected to be utilized as a starter culture for manufacturing fermented seaweed-sauce, which will be the first fermented food products obtained from algae.

The maturation of grafted bone after posterior lumbar interbody fusion with an interbody carbon cage: a prospective five-year study

We evaluated the maturation of grafted bone in cases of successful fusion after a one- or two-level posterior lumbar interbody fusion (PLIF) using interbody carbon cages. We carried out a five-year prospective longitudinal radiological evaluation of patients using plain radiographs and CT scans. One year after surgery, 117 patients with an early successful fusion were selected for inclusion in the study. Radiological evaluation of interbody bone fusion was graded on a 4-point scale. The mean grades of all radiological and CT assessments increased in the five years after surgery, and differences compared to the previous time interval were statistically significant for three or four years after surgery. Because the grafted bone continues to mature for three years after surgery, the success of a fusion should not be assessed until at least three years have elapsed. There were no significant differences in the longitudinal patterns of grafted bone maturity between iliac bone and local bone. However, iliac bone grafting may remodel faster than local bone.

Superior mesenteric vein thrombosis presented transient false positivity for lupus anticoagulant under heparin treatment

A 24-year-old Japanese man was admitted because of massive haematemesis and melaena with persistent abdominal pain. Markedly bloody ascites and severely oedematous small intestine were recognized, and angiography then revealed superior mesenteric vein thrombosis. After resection of the necrotic small intestine, continuous intravenous infusion of heparin and urokinase was performed. This patient had no familial or personal history of thrombosis. On the 15th day after operation, an initial search for lupus anticoagulant revealed that the prothrombin time (PT) ratio and dilute activated partial thromboplastin time (aPTT) were positive under heparin treatment, without evidence of rheumatic or connective tissue disease. Thrombocytopenia was observed with a nearly normocellular bone marrow. A follow-up examination 1 year later still revealed an increased aPTT. However, all tests for antiphospholipid antibodies had been negative including dilute aPTT for about 2 years since the 15th day after operation. These findings suggest that, in this patient, superior mesenteric vein thrombosis has not been associated with primary antiphospholipid syndrome but is probably idiopathic. Positive tests for lupus anticoagulant in the initial period may be unreliable due to heparin treatment.

Plasma procalcitonin in sepsis and organ failure

INTRODUCTION

Because the use of procalcitonin (PCT) as a marker of bacterial infection has been advocated, this study was carried out to determine the usefulness of plasma PCT in the early diagnosis and differentiation of patients with non-infectious systemic inflammatory response syndrome (SIRS) from those with sepsis, and the relationship between plasma PCT level and severity of organ failure.

MATERIALS AND METHODS

Thirty-five patients with non-septic SIRS (n = 16), sepsis (n = 7) or septic shock (n = 12) were included in this study. PCT and C-reactive protein (CRP) levels were measured and sepsis-related organ failure assessment (SOFA) score was calculated for these patients. Plasma PCT was measured by immunoluminometric assay.

RESULTS

The median (minimum, maximum) plasma PCT levels were 0.6 (0.1, 3.4) ng/mL in non-septic SIRS, 5.4 (0.9, 47.7) ng/mL in sepsis and 73.4 (9.6, 824.1) ng/mL in septic shock, and significant differences existed in plasma PCT levels among the three groups. The median (minimum, maximum) CRP levels were 13.8 (0.3, 48.8) mg/dL in non-septic SIRS, 23.3 (1.4, 26.6) mg/dL in sepsis and 17.4 (2.2, 34.1) mg/dL in septic shock, without significant differences among the three groups. A good correlation was found between plasma PCT level and SOFA score (rs = 0.766, P < 0.0001), although no correlation was found between CRP level and SOFA score.

CONCLUSIONS

CRP is increased by inflammatory disease as well as infection and is therefore not a good indicator of infection in patients with severe SIRS. On the other hand, PCT is a good indicator of severity of sepsis and organ failure in patients with severe SIRS since PCT levels correlated with sepsis and SOFA scores. PCT level is useful for diagnosis of sepsis and as an indicator of severity of organ failure in patients with SIRS.

Deformation and vascular occlusion of the growing rat femoral head induced by mechanical stress

To investigate the effects of mechanical stress on the extent of deformation and decrease of the blood supply to the femoral head in the growing rat, we conducted a histological and microangiographic study, using a custom-made hip-joint loading device. Application of a 1-kg to 3-kg load to the hip joint caused compression not only of the articular cartilage but also of the growth plate of the femoral head. These changes were particularly prominent in the lateral portion of the femoral head. The compression also caused complete occlusion of the lateral epiphyseal arteries, representing the blood supply to the femoral head, at the point of penetration into the epiphyseal cartilage. Our results indicate that the sum of forces during mechanical load application to the hip joint in growing rats acts to deform the cartilage of the lateral side of the femoral head. Our results also indicate the presence of a mechanically weak point in the femoral head which may lead to occlusion of the lateral epiphyseal arteries.

Genomic organization and mapping of mouse CDV (carnitine deficiency-associated gene expressed in ventricle)-1 and its related CDV-1R gene

We have previously reported that CDV (carnitine deficiency-associated gene expressed in ventricle)-1 was a downregulated gene in the hypertrophied ventricle of carnitine-deficient juvenile visceral steatosis mice and that the related gene (CDV-1R) showed no tissue specificity and no sensitivity to carnitine deficiency. In the present paper, the CDV-1/1R gene was isolated from a mouse genomic BAC library, and the genomic structure was characterized. We found that the CDV-1/1R gene consisted of at least 19 exons and encompassed approximately 48 kb. The splice sites conformed to the GT-AG rule, and the CDV-1R mRNA containing 19 exons was processed. CDV-1 mRNA containing 5 exons was constructed from the 3' half of CDV-1R. The first exon of CDV-1 consisted of the 3' side (116 bp) of intron 14 and exon 15 (87 bp) of CDV-1R. The presumed promoter sequence for CDV-1 located in the intron 14 of CDV-1R contained the common TATA box and consensus binding sites for various transcription factors (Nkx-2.5, Spl, C/EBP, SRF, YY1, and CREB), which seem to play roles in the heart-specific expression and carnitine deficiency-associated suppression of CDV-1. In the upstream region of the CDV-1 promoter, we found two VNTRs, 13 repeats of GATA1, and 16 copies of STRE involved in yeast stress response. The CDV-1/1R gene was located close to DSMIT68 on mouse Chromosome (Chr) 5, corresponding to human Chr 12q24. All these data revealed that two mRNA species, CDV-1 and CDV-1R, are expressed tissue-specifically by using promoters peculiar to each transcript in a single gene.

The signaling pathway of cardiotrophin-1 is not activated in hypertrophied ventricles of carnitine-deficient juvenile visceral steatosis (JVS) mice

Cardiotrophin-1 (CT-1) is a novel cytokine which is involved in the growth and survival of cardiac cells. We examined whether CT-1 plays a role in the development of cardiac hypertrophy in carnitine-deficient juvenile visceral steatosis (JVS) mice. The CT-1 mRNA level was quantitatively measured by the competitive RT-PCR method. In contrast to other models including spontaneously hypertensive rats, CT-1 mRNA in the ventricles of JVS mice was comparable to the control at 5 days and was less than half the control value at 2 and 8 weeks when the ventricles of the JVS mice were highly hypertrophied. There were no significant differences in CT-1 mRNA levels in the lung, liver, kidney, small intestine and skeletal muscle between the JVS and control mice at 2 weeks. We did not find any difference between JVS and control mice at 2 weeks in the mRNA level of ventricular leukemia inhibitory factor (LIF) which binds to the same receptor as CT-1. Furthermore, almost no phosphorylated STAT3 (signal transducer and activator of transcription 3), downstream of the LIF receptor and the gp130 signaling subunit, was observed in the ventricles of JVS and control mice. These data show that the CT-1 signaling pathway does not play a significant role in the development of cardiac hypertrophy in JVS mice. Furthermore, we could not detect any differences in insulin-like growth factor I and II mRNA levels. All these data suggest distinct differences in the mechanisms of cardiac hypertrophy between JVS mice and other model animals.

[Drug delivery system for the treatment of osteoporosis]

The number of agents for the treatment of osteoporosis has increased over the past few years allowing more and more differentiated therapy. Calcitonin, vitamin D3, bisphosphonate, estrogen, vitamin K2 and calcium are administered for the treatment of osteoporosis in Japan. The purpose of drug delivery system (DDS) is to provide a practical approach to increasing efficacy and minimizing side effects of the drugs. In fact by the development of DDS, topical administration, prodrug and targeting therapy are used in the treatment for osteoporosis. It is well known that calcitonin in susceptible to proteolysis in the intestine. So, calcitonin must be given intramuscular or subcutaneous injection for therapy. DDS of calcitonins is studying in many routes of administration, such as nasal, transdermal, ocular, oral, bronchial, rectal and vaginal.

Characteristics of blood vessels feeding the femoral head liable to osteonecrosis in spontaneously hypertensive rats

In order to elucidate the cause of osteonecrosis of the femoral head in spontaneously hypertensive rats (SHRs), which resembles the osteonecrosis of Perthes' disease, we observed the three-dimensional structure of vascular casts of the blood vessels feeding the femoral head using both optical and scanning electron microscopes. During the period of 9-15 weeks after birth, when osteonecrosis of the femoral heads in SHRs occurred frequently, the lateral epiphyseal vessels (LEVs), which were the main feeding vessels, entered from the lateral of the femoral heads. Anastomosing branches of LEVs between the epiphysis and the femoral neck were scarce even in the femoral heads showing normal ossification. It seemed that the development of LEVs in SHRs did not proceed normally in this period. Furthermore, remarkable segmental stenosis and the obstruction of LEVs were often recognized near the lateral of the femoral heads. These results suggest that LEVs in growing SHRs have the vascular structure that could cause an interruption of the blood supply to the femoral heads.

[Does a tracheal bifurcation shift upward due to increased intraabdominal pressure during laparoscopic surgery?]

To evaluate the influence of increased intraabdominal pressure on a position of tracheal bifurcation, we measured the distance from the tracheal bifurcation to the tip of the endotracheal tube which is fixed on a patient's mouth during a laparoscopic surgery. The distance decreased from 3.5 +/- 1.9 to 3.1 +/- 1.9 cm (P < 0.05) at mean intraabdominal pressure of 8.7 mmHg. This result suggests that the ventilation may become difficult due to the occlusion of the tip of the endotracheal tube by a tracheal bifurcation or due to inadvertent single lung ventilation under inappropriately deep intubation.

Degradation-resistant character of synthetic hydroxyapatite blocks filled in bone defects

The long-term changes of both the implanted hydroxyapatite (HA) blocks and the bone around them were observed radiologically to investigate the clinical usefulness of HA. HA blocks were used as a space filler in surgically created bone defects of seven cases due to curettage of bone tumours or removal for bone grafts, and they were followed up for 78 to 109 months. Bone formation around HA blocks peaked within 1 year after implantation, and then it faded gradually. However, shapes of HA blocks were rarely changed in all the cases. A clear zone around HA blocks was never observed . HA blocks were biocompatible and demonstrated a character resistant to degradation.

[Change in arterial ketone body ratio during gastrectomy and mastectomy]

We evaluated the influence of operative procedure on arterial ketone body ratio (AKBR), which indicates the function of the liver cells, in patients undergoing gastrectomy or mastectomy. AKBR during the stomach resection was significantly lower than that during the breast resection. A significant reduction in AKBR due to induced hypotension was observed in mastectomy group. SGOT and SGPT increased significantly in gastrectomy group, but unchanged in mastectomy group on the first and the seventh postoperative days. On the first post-operative day, SGOT and SGPT in gastrectomy group were significantly higher than those in mastectomy group. These findings suggest that influence of operative procedure on the liver during gastrectomy is more serious than that during mastectomy.

[Effect of prostaglandin E1 on arterial ketone body ratio during gastrectomy]

We evaluated the effect of prostaglandin E1 (PGE1) on arterial ketone body ratio (AKBR), which is a parameter to indicate the function of the liver cells, in the patients undergoing total or subtotal gastrectomy. Twenty patients were divided into two groups: continuous intravenous administration of PGE1 (0.02 micrograms.kg-1.min-1) was started from 30 minutes after the beginning of the operation in 10 patients, and the remainders did not receive PGE1. AKBR levels at 30 minutes after the beginning of the operation (during the resection of stomach) were significantly lower than those after the resection of stomach in both groups. A significant increase in AKBR caused by the administration of PGE1 was observed during the resection of the stomach in PGE1 group. However, almost no change was observed in AKBR during the resection of the stomach in control group. These findings suggest that the administration of PGE1 has a protective effect on liver which is due mainly to the increase in hepatic blood flow during the resection of stomach.

[Effect of hypocapnia on arterial oxygenation during induced hypotension]

We evaluated the effects of hypocapnia on arterial oxygenation during induced hypotension with nitroglycerin (TNG) or prostaglandin E1 (PGE1) in patients undergoing mastectomy. Of the 20 patients studied, 10 belonged to TNG group and 10 belonged to PGE1 group. Mean arterial pressure during induced hypotension was maintained at 70% of the values observed before hypotension. A significant decrease in PaO2 was observed during hypotension under normocapnia (PaCO2 35-40 mmHg) in both groups. In addition, small but significant reduction in PaO2 from 128.5 +/- 23.7 mmHg to 122.5 +/- 25.5 mmHg in TNG group and from 129.9 +/- 11.9 mmHG to 116.7 +/- 15.6 mmHg in PGE1 group were induced by hypocapnia (PaCO2 27-30 mmHg) during hypotension. These findings suggest that usual dose of TNG and PGE1 might not or might partially inhibit hypoxic pulmonary vasoconstriction.

[Effect of clamping of portal vein on serum potassium level during hepatic resection]

We studied relation between the serum potassium changes and the factors affecting serum potassium level during hepatic resection in 23 patients. Serum potassium concentration became significantly higher after hepatic resection. The magnitude of increase in serum potassium concentration showed a correlation with total clamping time of the right or left portal vein (r = 0.576, P less than 0.01) and also with the amount of blood transfused (r = 0.441, P less than 0.05), but no significant correlation was found with fall in pH and urine output during hepatic resection. These results suggest that the duration of clamping of portal vein play the key role in the increment in serum potassium concentration during hepatic resection.

[Ventricular fibrillation after administration of aclacinomycin emulsion into mesenteric lymph nodes in a patient anesthetized with enflurane, nitrous oxide and oxygen]

A 57-year-old man was given 40 mg of activated carbon aclacinomycin (ACM) emulsion into mesenteric lymph nodes during anesthesia with enflurane, nitrous oxide, oxygen and epidural anesthesia. He had no complications preoperatively. Immediately after the injection, his skin turned to red, and 5 minutes later, sinus tachycardia, R wave amplitude reduction, T wave amplitude elevation, QT prolongation and PVCs were noted, and then, ventricular fibrillation (Vf) occurred 15 minutes after the injection. We succeeded in electrical defibrillation within about 180 seconds. At that time, both arterial blood gas and electrocytes were normal. Serum ACM concentration was remarkably elevated 60 minutes after the administration, and remained high 22 hrs later. Postoperative course was uneventful and he was discharged on the 17th postoperative day. It has been said that ACM has relatively low cardiotoxicity compared with adriamycin because of rapid distribution and metabolism. However, it might cause cardiac complication such as ECG abnormality, heart failure, pericarditis, though the effects are transient and reversible. Therefore we should be ready for its rapid treatment. Coenzyme Q10 could counteract cardiotoxicity of ACM.

[Effect of induced hypotension on arterial blood ketone body ratio (AKBR)]

Arterial blood ketone body ratio (AKBR; acetoacetate/beta-hydroxybutyrate) is known as a parameter to indicate the function of the liver cells. We evaluated the effects of induced hypotension with prostaglandin E1 (PGE1) or trimetaphan (TMP) on AKBR in patients without liver disease undergoing mastectomy. Almost no change was observed in AKBR before, during and after hypotension with PGE1, but slight diminution was observed during hypotension with TMP. No hepatic dysfunction, however, developed in these patients postoperatively. These findings suggest that usual hypotension with TMP may provoke no postoperative hepatic dysfunction in patients without liver disease. For the patient who required either hypotension of long duration or hypotension with other factors affecting function of liver (surgical procedures, drugs and others), we prefer PGE1 to TMP as a hypotensive drug. We should also adopt PGE1 when cardiovascular control with hypotensive drug is necessary in patients with liver disease.

A case of facial diplegia associated with acute bilateral otitis media

A 32-month-old toddler developed facial diplegia in association with a bout of acute bilateral otitis media. After 28 days of antibiotic therapy and placement of tympanostomy tubes, the patient demonstrated 100% symmetrical recovery. A brief discussion of the pathophysiology is included.

A chemical carcinogen, 3-methylcholanthrene, alters T-cell function and induces T-suppressor cells in a mouse model system

The in-vivo effects of a polycyclic aromatic hydrocarbon (PAH), 3-methylcholanthrene (MCA), on in-vitro mitogen activation, cell-mediated lympholysis (CML) and T-cell subset distribution in mouse splenic lymphocyte populations were measured. Three inbred mouse strains were treated with a single intraperitoneal injection of corn oil alone or with different doses of MCA in oil (0.5-50 mg kg -1). One to ninety days after injection, splenic lymphocytes were isolated, and assayed for blastogenesis, CML and the percent T-helper and T-suppressor cells using monoclonal antibodies. High doses of MCA suppressed mitogen activation (15.2-53.6%) and CML (69-90%) within 24 hr in lymphocytes from PAH-responsive mice (C57 and C3H). Blastogenesis was stimulated and CML was suppressed to a lesser degree (5-45%) in lymphocytes from non-responsive mice (DBA). MCA induced an increase in T-suppressor cells in responsive mice, but there was no change in DBA mice. These studies suggest a correlation between immunocytotoxicity of PAH compounds on T-cell subsets and the responsiveness of mouse strains to these carcinogens.

Measurement of intrahepatic shunted blood flow by ethanol-1-14C method as compared with D-galactose-1-14C method

Ethanol-1-14C method for the measurement of intrahepatic shunted blood flow was compared with the method of continuous infusion of D-galactose-1-14C. In controls, in chronic hepatitis, and in hepatic cirrhosis, per cent intrahepatic shunt measured by the ethanol-1-14C- method was about a half or one-third of that measured by the D-galactose-1-14C method. Study of radioactivity-dye concentration ratio of the blood sampled from the inferior vena cava showed that per cent intrahepatic shunt was underestimated by the ethanol-1-14C method because of permeability of ethanol-1-14C through the capillaries. In patients with hepatic carcinoma, in whom the carcinomatous tissue was supplied mainly by the hepatic artery, there was no significant difference in per cent intrahepatic shunt between both methods.