Dysbiosis of gut microbiota in patients with protein-losing enteropathy after the Fontan procedure

BACKGROUND

There is a lack of predictive biomarkers for the onset or activity of protein-losing enteropathy (PLE), a Fontan procedure-associated complication. Here, we aimed to identify the gut microbiota composition of patients with active PLE and investigate its relationship with PLE activity.

METHODS

This multicenter case-control study involved patients who developed PLE (n = 16) after the Fontan procedure and those who did not (non-PLE; n = 20). Patients with PLE who maintained a serum albumin level of ≥3 g/dL for >1 year were included in the remissive-stage-PLE group (n = 9) and those who did not maintain this level were included in the active-PLE group (n = 7). 16S rRNA gene sequencing analysis of fecal samples was performed using QIIME2 pipeline. Alpha (Shannon and Faith's phylogenetic diversity indices) and beta diversity was assessed using principal coordinate analysis based on unweighted UniFrac distances.

RESULTS

Shannon and Faith's phylogenetic diversity indices were lower in the active-PLE group than in the remissive-stage- (q = 0.028 and 0.025, respectively) and non-PLE (q = 0.028 and 0.017, respectively) groups. Analysis of beta diversity revealed a difference in the microbiota composition between the active-PLE and the other two groups. Linear discriminant effect size analysis demonstrated differences in the relative abundance of Bifidobacterium and Granulicatella spp., and Ruminococcus torques between patients with active- and those with remissive-stage-PLE.

CONCLUSIONS

Gut microbiota dysbiosis was observed in patients with active PLE. Changes in the bacterial composition of the gut microbiota and decreased diversity may be associated with the severity of PLE.

Analysis of Coronary Arterial Aneurysm Regression in Patients With Kawasaki Disease by Aneurysm Severity: Factors Associated With Regression

Background Coronary arterial aneurysms (CAAs) associated with Kawasaki disease (KD) significantly affect prognosis. However, the clinical course of CAAs and factors associated with CAA regression have not been well analyzed. Methods and Results The cohort of the Z-Score 2nd Project Stage study, a multicenter, retrospective, cohort study involving 44 institutions in Japan including 1006 patients with KD, was examined. CAAs were classified by the z score of their internal diameter in the acute phase: small (z<5), medium (5≤z<10), and large (z≥10). The lower limit of small CAA was based on the Japanese Ministry of Health, Labour and Welfare criteria. In the right coronary artery, the CAA regression rates 10 years after diagnosis were 95.5% for small, 83.2% for medium, and 36.3% for large. In the proximal left anterior descending artery, the regression rates 10 years after diagnosis were 95.3% for small, 80.1% for medium, and 28.8% for large. Cox regression analysis showed that diagnosis under the age of 1 year and onset of KD in 2010 to 2012 for the right coronary artery and the left anterior descending artery, and female for the right coronary artery were significantly associated with a high regression rate, whereas large CAAs for the right coronary artery and the left anterior descending artery were significantly associated with a low regression rate. Conclusions The current study, the largest Japanese study of its kind, found that small aneurysm, recent onset, and diagnosis under the age of 1 year predict regression, and that even giant aneurysms could regress. These data may contribute to long-term management of coronary aneurysms. Registration URL: https://www.umin.ac.jp/ctr/; Unique identifier: UMIN000010606.

Case report: High-dose epoprostenol therapy in pediatric patients with pulmonary hypertension and developmental lung disease

Pulmonary hypertension (PH) with developmental lung disease is a life-threatening disease and accounts for 10%-12% of pediatric PH patients. Administration of specific pulmonary vasodilators to pediatric PH patients has brought about improvement of their long-term prognosis. Intravenous epoprostenol therapy is a gold standard therapy for severe idiopathic pulmonary arterial hypertension (IPAH), but there are few reports demonstrating the efficacy of epoprostenol for pediatric PH patients with developmental lung disease, especially when treating with high doses of epoprostenol. Two cases of pediatric PH patients with alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) and congenital diaphragmatic hernia (CDH) with bronchopulmonary dysplasia (BPD), respectively, treated with epoprostenol above 100 ng/kg/min are presented. In these two cases, severe PH was improved significantly by an aggressive increase of the epoprostenol infusion rate with administration of oral pulmonary vasodilators and appropriate respiratory management, without any significant adverse effects. High-dose epoprostenol therapy may be one of the therapeutic options in pediatric PH patients with developmental lung disease.

Conception by assisted reproductive technology in infants with critical congenital heart disease in Japan

RESEARCH QUESTION

What is the proportion of infants born as a result of assisted reproductive technology ART across different types of neonatal critical congenital heart disease (CCHD) in a Japanese population?

DESIGN

A retrospective analysis of 418 consecutive infants with CCHD that required catheter treatment or surgery within the first 28 days of life or ductal-dependent lesions, in two paediatric centres in Japan, between January 2014 and December 2019. The proportion of ART in infants with each type of CCHD was evaluated. The proportion of ART in infants with univentricular heart defect (UVH) compared with those with biventricular heart defect (BVH) was evaluated.

RESULTS

The study group included 229 boys and 189 girls, with a gestational age of 38 ± 2 weeks. Overall, 61 infants (14.6%) were conceived by fertility treatment with 46 (11.0%) conceived by ART. Univentricular heart defect and BVH were identified in 111 infants (26.6%) and 307 infants (73.4%), respectively. The proportion of infants conceived by ART was significantly higher in UVH (16.2%) than in BVH (9.1%) (OR 2.28, 95% CI 1.11 to 4.68, P = 0.025), regardless of maternal age and maternal history of miscarriage.

CONCLUSIONS

The proportion of ART in infants with CCHD, especially UVH, was high. These findings could form the basis of a rationale for carrying out fetal echocardiography in fetuses conceived by ART.

Echocardiography Monitoring of Pulmonary Hypertension after Pediatric Hematopoietic Stem Cell Transplantation: Pediatric Pulmonary Arterial Hypertension and Pulmonary Veno-Occlusive Disease after Hematopoietic Stem Cell Transplantation

Pulmonary hypertension (PH) is associated with high morbidity in children undergoing hematopoietic stem cell transplantation (HSCT). However, owing to the lack of sequential echocardiography, the nature of the condition is not fully understood. This study was conducted to investigate whether routine echocardiography performed after HSCT could detect patients with PH at an earlier stage and elucidate the role of intervention using tadalafil. The study population comprised 93 consecutive children age <18 years who underwent a total of 109 HSCTs. All patients underwent routine transthoracic echocardiography during HSCT. Four children (4%) with a median age of 4 years (range, 0.7 to 6 years) were found to have PH, and their median tricuspid regurgitation peak velocity (TRV) was 4.1 m/s (range, 3.5 to 4.2 m/s). PH was diagnosed at a median of 52 days (range, 21 to 118 days) after HSCT. Three of them were diagnosed with neuroblastoma, and 1 was diagnosed with infantile leukemia. One patient developed PH after autologous HSCT, and 3 received killer immunoglobulin-like receptor ligand-mismatched cord blood. Busulfan was used for conditioning in all patients, and the proportion of patients receiving this medication was significantly higher in the PH group compared with the non-PH group (100% versus 30%; P = .011). Three of the 4 patients had a durable response (TRV ≤2.8 m/s) at a median of 46 days (range, 14 to 79 days) after starting treatment with tadalafil. No patient experienced exacerbation of PH, and treatment was completed at median of 96 days (range, 46 to 212 days). Our data suggest that routine echocardiography monitoring after HSCT should be considered in children receiving busulfan, although the precise follow-up timing needs further study. In addition, safe and effective administration of tadalafil must be ensured by close monitoring.

Successful treatment of a novel type I interferonopathy due to a de novo PSMB9 gene mutation with a Janus kinase inhibitor

BACKGROUND

Type I interferonopathies are a recently established subgroup of autoinflammatory diseases caused by mutations in genes associated with proteasome degradation or cytoplasmic RNA- and DNA-sensing pathways.

OBJECTIVE

This study aimed to unveil the molecular pathogenesis of a patient with novel type I interferonopathy, for which no known genetic mutations have been identified.

METHODS

We performed the whole-exome sequencing of a 1-month-old boy with novel type I interferonopathy. We also investigated proteasome activities using patient-derived B lymphoblastoid cell lines (LCLs) and normal LCLs transduced with the mutant gene.

RESULTS

Whole-exome sequencing identified a de novo proteasome 20S subunit beta 9 (PSMB9) p.G156D mutation in the patient who developed fever, a chilblain-like skin rash, myositis, and severe pulmonary hypertension due to the hyperactivation of IFN-α. Patient-derived LCLs revealed reduced proteasome activities, and exogenous transduction of mutant PSMB9 p.G156D into normal LCLs significantly suppressed proteasome activities, and the endogenous PSMB9 protein was lost along with the reduction of other immunoproteasome subunits, PSMB8 and PSMB10 proteins. He responded to the administration of a Janus kinase inhibitor, tofacitinib, and he was successfully withdrawn from venoarterial extracorporeal membranous oxygenation. At age 7 months, he received an unrelated cord blood transplantation. At 2 years posttransplantation, he no longer required tofacitinib and experienced no disease recurrence.

CONCLUSIONS

We present the case of a patient with a novel type I interferonopathy caused by a de novo PSMB9 p.G156D mutation that suppressed the wild-type PSMB9 protein expression. Janus kinase inhibitor and stem cell transplantation could be curative therapies in patients with severe interferonopathies.

Phosphorylated proteome analysis of a novel germline ABL1 mutation causing an autosomal dominant syndrome with ventricular septal defect

BACKGROUND

A gain-of-function mutation in germline ABL1 causes a syndrome including congenital heart defects. However, the molecular mechanisms of this syndrome remain unknown. In this study, we found a novel ABL1 mutation in a Japanese family with ventricular septal defect, finger contracture, skin abnormalities and failure to thrive, and the molecular mechanisms of these phenotypes were investigated.

METHODS AND RESULTS

Whole-exome sequencing on several family members revealed a novel mutation (c.1522A > C, p.I508L) in the tyrosine kinase domain of ABL1, and complete co-segregation with clinical presentations was confirmed in all members. Wild-type and mutant ABL1 were transfected into human embryonic kidney 293 cells for functional analysis. Western blotting confirmed that tyrosine phosphorylation in STAT5, a substrate of ABL1, was enhanced, and the novel mutation was proved to be a gain-of-function mutation. Since this novel mutation in ABL1 enhances tyrosine kinase activity, phosphorylated proteome analysis was used to elucidate the molecular pathology. The proteome analysis showed that phosphorylation in proteins such as UFD1, AXIN1, ATRX, which may be involved in the phenotypes, was enhanced in the mutant group.

CONCLUSIONS

The onset of congenital heart defects associated with this syndrome appears to involve a mechanism caused by UFD1 common to 22q.11.2 deletion syndrome. On the other hand, AXIN1 and ATRX may be important in elucidating the mechanisms of other phenotypes, such as finger contracture and failure to thrive. Verification of these hypotheses would lead to further understanding of the pathophysiology and the development of treatment methods.

Prediction of postnatal clinical course in primary congenital dilated cardiomyopathy

BACKGROUND

The aim of this study was to investigate the prediction of postnatal prognosis using fetal and perinatal data in patients with primary congenital dilated cardiomyopathy (PCDCM), and to estimate the incidence of this disease.

METHODS

We examined correlations between fetal or perinatal data and postnatal clinical course in a multicenter retrospective study of eight patients with PCDCM. Incidence was calculated in a population-based study.

RESULTS

All patients developed heart failure at a median of 8 days (range, 0-43 days), and six patients died or required extracorporeal artificial heart therapy at a median of 67 days (range, 0-92 days). The cardiothoracic area ratio from fetal echocardiography, the Apgar score, and the standard deviation of birth weight correlated significantly with the date at onset of heart failure. However, no data correlated with survival. Cumulative incidence of PCDCM was calculated as 1.21 per 100 000 total births (95% confidence interval, 0.37 to 2.06).

CONCLUSIONS

Primary congenital dilated cardiomyopathy has a poor prognosis, but cardiothoracic area ratio from fetal echocardiography, body weight at birth, and Apgar score correlate with the timing of the onset of heart failure, and these indicators might therefore be useful for peri- and postnatal management.

Frequent intragenic microdeletions of elastin in familial supravalvular aortic stenosis

BACKGROUND

Supravalvular aortic stenosis (SVAS) is a congenital heart disease affecting approximately 1:25,000 live births. SVAS may occur sporadically, be inherited in an autosomal dominant manner, or be associated with Williams-Beuren syndrome, a complex developmental disorder caused by a microdeletion of chromosome 7q11.23. ELN on 7q11.23, which encodes elastin, is the only known gene to be recurrently mutated in less than half of SVAS patients.

METHODS

Whole-exome sequencing (WES) was performed for seven familial SVAS families to identify other causative gene mutations of SVAS.

RESULTS

Three truncating mutations and three intragenic deletions affecting ELN were identified, yielding a diagnostic efficiency of 6/7 (85%). The deletions, which explained 3/7 of the present cohort, spanned 1-29 exons, which might be missed in the course of mutational analysis targeting point mutations. The presence of such deletions was validated by both WES-based copy number estimation and multiplex ligation-dependent probe amplification analyses, and their pathogenicity was reinforced by co-segregation with clinical presentations.

CONCLUSIONS

The majority of familial SVAS patients appear to carry ELN mutations, which strongly indicates that elastin is the most important causative gene for SVAS. The frequency of intragenic deletions highlights the need for quantitative tests to analyze ELN for efficient genetic diagnosis of SVAS.

Successful Infant Pneumonectomy with Unilateral Pulmonary Artery Occlusion Test

The use of unilateral pulmonary artery occlusion (UPAO) test for the preoperative evaluation of pneumonectomy was reported in adult patients. On the contrary, in infants, no strategies have yet been recommended to predict hemodynamics after pneumonectomy, nor has use of the UPAO test been reported. We describe the first case of infant with abnormal pulmonary circulation in whom successful pneumonectomy was performed after preoperative evaluation using UPAO test. Right pneumonectomy was planned for an 8-month-old girl, because of decreased right pulmonary function, high risk of pneumothorax, and impaired left lung expansion due to overexpansion caused by severe left bronchial stenosis and bronchomalacia. However, she had also prolonged pulmonary hypertension and there was difficulty in accurate echocardiographic evaluation of its severity due to concomitant left pulmonary artery stenosis. Furthermore, contrast-enhanced computer tomography suggested a certain degree of right pulmonary venous flow, discordant with the result showing scarce right pulmonary flow in perfusion scintigraphy. Predicting postoperative hemodynamic changes was therefore considered difficult. To evaluate these concerns, we performed cardiac catheterization and UPAO test to simulate postoperative hemodynamics. Pulmonary arteriography showed decreased but significant right pulmonary arterial and venous flows. Measurements including pulmonary artery pressure and cardiac index showed no marked changes after occlusion. Based on UPAO test results, the operation was successfully performed and hemodynamics remained stable postoperatively. The UPAO test may be useful for infants with cardiopulmonary impairment to evaluate the tolerability of pneumonectomy.

Long-term outcome in Japanese patients with lupus nephritis

The objective of this study was to clarify the long-term outcome in patients with lupus nephritis (LN) according to the International Society of Nephrology and Renal Pathology Society classification. This retrospective analysis comprised 186 Japanese patients given a diagnosis of LN by renal specimen with a mean observation period of 12 years. Primary end point was defined as death or end-stage renal disease, and standardized mortality ratios were calculated. Five patients presented with histopathological class I, 62 with II, 21 with III or III+V, 73 with IV or IV+V and 25 with V. Fourteen deaths occurred, corresponding to an overall standardized mortality ratio of 3.59 (95% confidence interval 2.02-5.81, p < 0.0001). Kaplan-Meier analysis revealed a 10-year overall survival of 95.7%. Nephrotic proteinuria (≥3.5 g/day) at baseline was identified as an independent poor prognostic factor for overall survival in Cox regression analysis. Kaplan-Meier analysis revealed a 10-year renal survival as 94.3%. Male gender and nephrotic proteinuria at baseline were identified as independent poor prognostic factors for renal survival in Cox regression analysis. In conclusion, LN was associated with a 3.59-fold increase in mortality compared with the general population. Male gender and nephrotic proteinuria were predictive for poor renal outcome.

Incidentally detected parafalcine chondrosarcoma

Parafalcine chondrosarcoma is extremely rare, and may be difficult to differentiate preoperatively from falx meningioma. An 18-year-old woman presented with a parafalcine chondrosarcoma incidentally detected as a small lesion 2 years before admission, suggesting falx meningioma. Brain computed tomography and magnetic resonance imaging just before admission revealed the parafalcine lesion had increased by about nine times in volume during the last 2 years. Single-photon emission computed tomography (SPECT) after intravenous administration of both thallium-201 chloride ((201)TlCl) and N-isopropyl-p-[(123)I]iodoamphetamine ((123)I-IMP) demonstrated no abnormal uptake of either tracer. Histological examination revealed classic low-grade chondrosarcoma. Parafalcine chondrosarcoma should be considered at this site if relatively rapid growth is observed. SPECT using (201)TlCl and (123)I-IMP may be useful to discriminate parafalcine low-grade chondrosarcoma from meningioma or other tumours originating in this region.

Estimation of preservative concentrations in foods and their daily intake based on official inspection results in Japan in fiscal year 1998

The mean concentration and daily intake of five preservatives were estimated based on the results of an analysis of 89,927 samples of food obtained in official inspections by Japanese local governments in fiscal year 1998. The mean concentration of benzoic acid was 9.5% of the allowable limit, and those of dehydroacetic acid, p-hydroxybenzoic acid, propionic acid, and sorbic acid were 1.5%, 5.7%, 1.7%, and 23.9%, respectively. Daily intake levels of these preservatives per person estimated from the concentration and daily consumption of foods were 6.23 mg, 0.0303 mg, 1.02 mg, 8.10 mg, and 25.0 mg, respectively, and assuming a body weight of 50 kg, the amounts of benzoic acid, p-hydroxybenzoic acid, and sorbic acid consumed were 2.5%, 0.2%, and 2.0% of their acceptable daily intakes, respectively. These values were similar to those obtained based on the results of the official inspections in fiscal years 1994 and 1996.

Human L-type amino acid transporter 1 (LAT1): characterization of function and expression in tumor cell lines

System L is a major nutrient transport system responsible for the transport of large neutral amino acids including several essential amino acids. We previously identified a transporter (L-type amino acid transporter 1: LAT1) subserving system L in C6 rat glioma cells and demonstrated that LAT1 requires 4F2 heavy chain (4F2hc) for its functional expression. Since its oncofetal expression was suggested in the rat liver, it has been proposed that LAT1 plays a critical role in cell growth and proliferation. In the present study, we have examined the function of human LAT1 (hLAT1) and its expression in human tissues and tumor cell lines. When expressed in Xenopus oocytes with human 4F2hc (h4F2hc), hLAT1 transports large neutral amino acids with high affinity (K(m)= approximately 15- approximately 50 microM) and L-glutamine and L-asparagine with low affinity (K(m)= approximately 1.5- approximately 2 mM). hLAT1 also transports D-amino acids such as D-leucine and D-phenylalanine. In addition, we show that hLAT1 accepts an amino acid-related anti-cancer agent melphalan. When loaded intracellularly, L-leucine and L-glutamine but not L-alanine are effluxed by extracellular substrates, confirming that hLAT1 mediates an amino acid exchange. hLAT1 mRNA is highly expressed in the human fetal liver, bone marrow, placenta, testis and brain. We have found that, while all the tumor cell lines examined express hLAT1 messages, the expression of h4F2hc is varied particularly in leukemia cell lines. In Western blot analysis, hLAT1 and h4F2hc have been confirmed to be linked to each other via a disulfide bond in T24 human bladder carcinoma cells. Finally, in in vitro translation, we show that hLAT1 is not a glycosylated protein even though an N-glycosylation site has been predicted in its extracellular loop, consistent with the property of the classical 4F2 light chain. The properties of the hLAT1/h4F2hc complex would support the roles of this transporter in providing cells with essential amino acids for cell growth and cellular responses, and in distributing amino acid-related compounds.

Transport properties of a system y+L neutral and basic amino acid transporter. Insights into the mechanisms of substrate recognition

The properties of system y(+)L-mediated transport were investigated on rat system y(+)L transporter, ry(+)LAT1, coexpressed with the heavy chain of cell surface antigen 4F2 in Xenopus oocytes. ry(+)LAT1-mediated transport of basic amino acids was Na(+)-independent, whereas that of neutral amino acids, although not completely, was dependent on Na(+), as is typical of system y(+)L-mediated transport. In the absence of Na(+), lowering of pH increased leucine transport, without affecting lysine transport. Therefore, it is proposed that H(+), besides Na(+) and Li(+), is capable of supporting neutral amino acid transport. Na(+) and H(+) augmented leucine transport by decreasing the apparent K(m) values, without affecting the V(max) values. We demonstrate that although ry(+)LAT1-mediated transport of [(14)C]l-leucine was accompanied by the cotransport of (22)Na(+), that of [(14)C]l-lysine was not. The Na(+) to leucine coupling ratio was determined to be 1:1 in the presence of high concentrations of Na(+). ry(+)LAT1-mediated leucine transport, but not lysine transport, induced intracellular acidification in Chinese hamster ovary cells coexpressing ry(+)LAT1 and 4F2 heavy chain in the absence of Na(+), but not in the presence of physiological concentrations of Na(+), indicating that cotransport of H(+) with leucine occurred in the absence of Na(+). Therefore, for the substrate recognition by ry(+)LAT1, the positive charge on basic amino acid side chains or that conferred by inorganic monovalent cations such as Na(+) and H(+), which are cotransported with neutral amino acids, is presumed to be required. We further demonstrate that ry(+)LAT1, due to its peculiar cation dependence, mediates a heteroexchange, wherein the influx of substrate amino acids is accompanied by the efflux of basic amino acids.

Identification and characterization of a Na(+)-independent neutral amino acid transporter that associates with the 4F2 heavy chain and exhibits substrate selectivity for small neutral D- and L-amino acids

A cDNA was isolated from the mouse brain that encodes a novel Na(+)-independent neutral amino acid transporter. The encoded protein, designated as Asc-1 (asc-type amino acid transporter 1), was found to be structurally related to recently identified mammalian amino acid transporters for the transport systems L, y(+)L, x(C)(-), and b(0,+), which are linked, via a disulfide bond, to the type II membrane glycoproteins, 4F2 heavy chain (4F2hc), or rBAT (related to b(0,+) amino acid transporter). Asc-1 required 4F2hc for its functional expression. In Western blot analysis in the nonreducing condition, a 118-kDa band, which seems to correspond to the heterodimeric complex of Asc-1 and 4F2hc, was detected in the mouse brain. The band shifted to 33 kDa in the reducing condition, confirming that Asc-1 and 4F2hc are linked via a disulfide bond. Asc-1-mediated transport was not dependent on the presence of Na(+) or Cl(-). Although Asc-1 showed a high sequence homology (66% identity at the amino acid level) to the Na(+)-independent broad scope neutral amino acid transporter LAT2 (Segawa, H., Fukasawa, Y., Miyamoto, K., Takeda, E., Endou, H., and Kanai, Y. (1999) J. Biol. Chem. 274, 19745-19751), Asc-1 also exhibited distinctive substrate selectivity and transport properties. Asc-1 preferred small neutral amino acids such as Gly, L-Ala, L-Ser, L-Thr, and L-Cys, and alpha-aminoisobutyric acid as substrates. Asc-1 also transported D-isomers of the small neutral amino acids, in particular D-Ser, a putative endogenous modulator of N-methyl-D-aspartate-type glutamate receptors, with high affinity. Asc-1 operated preferentially, although not exclusively, in an exchange mode. Asc-1 mRNA was detected in the brain, lung, small intestine, and placenta. The functional properties of Asc-1 seem to be consistent with those of a transporter subserving the Na(+)-independent small neutral amino acid transport system asc.

Identification and functional characterization of a Na+-independent neutral amino acid transporter with broad substrate selectivity

We have isolated a cDNA from rat small intestine that encodes a novel Na+-independent neutral amino acid transporter with distinctive characteristics in substrate selectivity and transport property. The encoded protein, designated L-type amino acid transporter-2 (LAT-2), shows amino acid sequence similarity to the system L Na+-independent neutral amino acid transporter LAT-1 (Kanai, Y., Segawa, H., Miyamoto, K., Uchino, H., Takeda, E., and Endou, H. (1998) J. Biol. Chem. 273, 23629-23632) (50% identity) and the system y+L transporters y+LAT-1 (47%) and KIAA0245/y+LAT-2 (45%) (Torrents, D., Estevez, R., Pineda, M., Fernandez, E., Lloberas, J., Shi, Y.-B., Zorzano, A., and Palacin, M. (1998) J. Biol. Chem. 273, 32437-32445). LAT-2 is a nonglycosylated membrane protein. It requires 4F2 heavy chain, a type II membrane glycoprotein, for its functional expression in Xenopus oocytes. LAT-2-mediated transport is not dependent on Na+ or Cl- and is inhibited by a system L-specific inhibitor, 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH), indicating that LAT-2 is a second isoform of the system L transporter. Compared with LAT-1, which prefers large neutral amino acids with branched or aromatic side chains, LAT-2 exhibits remarkably broad substrate selectivity. It transports all of the L-isomers of neutral alpha-amino acids. LAT-2 exhibits higher affinity (Km = 30-50 microM) to Tyr, Phe, Trp, Thr, Asn, Ile, Cys, Ser, Leu, Val, and Gln and relatively lower affinity (Km = 180-300 microM) to His, Ala, Met, and Gly. In addition, LAT-2 mediates facilitated diffusion of substrate amino acids, as distinct from LAT-1, which mediates amino acid exchange. LAT-2-mediated transport is increased by lowering the pH level, with peak activity at pH 6.25, because of the decrease in the Km value without changing the Vmax value. Because of these functional properties and a high level of expression of LAT-2 in the small intestine, kidney, placenta, and brain, it is suggested that the heterodimeric complex of LAT-2 and 4F2 heavy chain is involved in the trans-cellular transport of neutral amino acids in epithelia and blood-tissue barriers.

Retention mechanism of imidazoles in connective tissue. IV. Identification of a nucleophilic imidazolone metabolite in rats

Formation of a nucleophilic 4(5H)(or 5(4H))-imidazolone structure has been postulated from in vitro studies to be one of the causative elements involved in the retention of drugs with imidazole moiety in connective tissue. To confirm this, we searched for the imidazolone-related metabolite in rats after intravenous dosing of 2-methylimidazole (2MI; 14C-labeled and unlabeled form, 3 and 300 micromol/kg body weight) as a model compound. The excreted urine, the major route of elimination of the compound, was collected and analyzed using the HPLC/MS system with a counterion effect for metabolite separation. 2-Methyl-4(5H)(or 5(4H))-imidazolone (2MIone) was identified as a urinary metabolite by chromatographic and mass-spectral inspection with the corresponding authentic standard. Pretreatment of rats with either SKF-525A (50 mg/kg, i.p.) or cimetidine (200 mg/kg, i.p.) significantly increased the excreted amount of 2MIone in urine and the irreversible binding of 2MI equivalents in the aortic tissue, whereas both factors were reduced by pretreatment with triethylenetetramine dihydrochloride (150 mg/kg/d for 5 d, s.c.). These results support the aforementioned deduction, and also raise the possibility that a cytochrome P450-independent, copper-related metabolic reaction might be involved in the imidazolone formation in vivo.

Retention mechanism of imidazoles in connective tissue. III. Aldehyde adduct formation of a 4(5H)(or5(4H))-imidazolone product in vitro

2-Methylimidazole (2MI), as well as imidazole, has been thought to undergo cupro-ascorbate (Cu-VC)-catalyzed oxidative transformation in vitro to become a reactive species capable of combining with aldehydes intrinsic to connective-tissue proteins. We attempted to seize the essence of the above reaction through obtaining the structural information of an aldehyde-bonding species. As major products from 2MI in the in vitro Cu-VC system, 2-hydroxymethylimidazole (2(OH)MI) and 2-methyl-4(5H)(or 5(4H))-imidazolone (2MIone) were identified by mass-spectral and chromatographic comparison with the corresponding authentic standards synthesized. The in situ addition of acetaldehyde or propionaldehyde as a simple protein-aldehyde model to the system resulted in the deducible formation of an aldol condensate, 2-methyl-4(or 5)-ethylidene-4(5H)(or 5(4H))-imidazolone (2MEIone) or its possible analogue with a propylidene moiety, respectively. The authentic compound of 2MIone directly reacted with acetaldehyde and easily afforded the products assignable to the isomers of 2MEIone through the ethylidene moiety at physiological pH and temperature, whereas neither 2MI or 2(OH)MI reacted at all. These results suggest that a 4(5H)(or 5(4H))-imidazolone product, although simply a monooxygenated form, is sufficiently reactive to give aldol condensation-typed covalent adducts with aldehydes, even under physiological conditions, probably having an activated methylene moiety in the ring structure. Based on the present results, we discussed the mechanism of the retention of imidazole-containing drugs in connective tissue.

Mutation in pncA is a major mechanism of pyrazinamide resistance in Mycobacterium tuberculosis

OBJECTIVE

To characterize the correlation of the mutations in the pncA gene encoding pyrazinamidase (PZase) of Mycobacterium tuberculosis to a loss of PZase activity and development of pyrazinamide (PZA) resistance.

DESIGN

The association of PZase activity, minimum inhibitory concentrations (MICs), and mutations in the pncA gene of M. tuberculosis isolated in mostly Asian countries was investigated.

RESULTS

One hundred thirty-five out of 168 isolates were PZase positive, and 33 were negative. The MICs of PZA at pH 6.0 were over 400 micrograms/ml for all 33 PZase-negative isolates, while those of PZase-positive isolates were equal to or less than 200 micrograms/ml. Among 33 PZase-negative isolates sequenced, 32 (97%) had mutations within the pncA gene. A mutation was seen in various regions throughout the pncA gene. It was surprising that all three strains of in vitro selected PZA resistant mutants were PZase-positive and showed no change in the pncA gene. These results indicate that additional mechanisms may be involved in PZA resistance. No mutations were observed in all of 135 PZase-positive M. tuberculosis isolates tested, indicating that mutations in the pncA gene could be involved in the loss of PZase activity.

CONCLUSIONS

Sequencing analysis of the pncA gene should provide rapid diagnosis of PZA resistant clinical isolates of M. tuberculosis.

Solitary fibrous tumor of the pleura causing recurrent hypoglycemia by secretion of insulin-like growth factor II

A case of malignant solitary fibrous tumor (SFT) is reported, occurring in a 61-year-old man with frequent hypoglycemia. Endocrinological analyses showed high serum levels of insulin-like growth factor II (IGF-II) and suppressed secretion of insulin. After the removal of a pleural tumor, which weighed 3150 g, serum IGF-II levels returned to normal and hypoglycemic attacks ceased. The tumor was composed of uniform spindle cells arranged in bundles, and fascicles with varying amounts of collagen and reticulin fibers. Mitotic figures at the rate of 6/10 high-power fields, and frequent foci of necrosis and hemorrhage were seen. Almost all of the tumor cells were immunohistochemically positive for vimentin and CD34. Electron microscopy revealed the immature mesenchymal or myofibroblastic nature of the tumor cells. These findings are consistent with malignant SFT of the pleura. Moreover, the tumor produced IGF-II mRNA as demonstrated by northern blot analysis. Thus, hypoglycemia of this patient was induced by SFT through the production and secretion of IGF-II.

Pharmacokinetic and pharmacodynamic studies of centrally acting drugs in rat: effect of pentobarbital and chlorpromazine on electroencephalogram in rat

Electroencephalogram (EEG) alterations in rat after the i.v. administration of pentobarbital (PTB) and chlorpromazine (CPZ) were measured by power spectral analysis. The time courses of PTB concentrations in plasma, cerebrospinal fluid (CSF) and brain were determined after the i.v. administration of PTB (20, 40 mg/kg) by GC-MS. The PTB concentrations in plasma, CSF and brain could be described by a biexponential equation, a CSF model and a blood flow limited model, respectively. The relationship between the alteration of EEG and the PTB concentrations in the CSF or brain or the effect compartment were analyzed using the sigmoid Emax model. The alteration of EEG after PTB administration could be described by the PTB concentration in these compartments using the sigmoid Emax model. These results indicated that the site of action for the alteration of EEG after PTB administration is in instantaneous equilibrium with the CSF, the brain and the effect compartment. Thus, alterations in EEG after PTB administration can be predicted by monitoring the total PTB concentration in plasma. The alteration of EEG after i.v. administration of CPZ (4 mg/kg) showed a two-phase variation. Although the relationship between the alteration of EEG and the CPZ concentrations in CSF or the striatum or the effect compartment (total and free drug) were analyzed using the linear model, the Emax model or the sigmoid Emax model, the two-phase alteration of EEG after CPZ administration could not be described by any of these models. These results indicated that the pharmacokinetic and pharmacodynamic modeling of CPZ during the alteration of EEG may be complicated due to several pharmacokinetic and pharmacodynamic factors, such as an alteration of the free fraction of CPZ in the striatum, the formation of active metabolites, and two different intrinsic effects of CPZ on the EEG (one in an increase and the other in a decrease of the brain's electrical activity.

Massive apoptosis in infantile myofibromatosis. A putative mechanism of tumor regression

Two cases of solitary infantile myofibromatosis (IM) are presented. Solitary IM are tumors prone to spontaneous regression. Histopathologically, several tumor lobules in our IM cases had central areas of massive cell death, with nuclear pyknosis, cytoplasmic hyalinization and nuclear fragmentation but without lymphoid or neutrophilic cell infiltration. These central cell death areas consisted of about 40% in case 2 and 50% in case 1 of the entire tumor tissues, respectively. Electron microscopy revealed that the condensed nuclei and cytoplasm were fragmented into "apoptotic bodies", with or without phagocytosis by histiocytes. DNA fragmentation, as evidenced by the terminal deoxy transferase-mediated uptake of biotinylated dUTP, was identified at massive cell death areas on paraffin sections from both cases. A characteristic 180- to 190-bp nucleosomal ladder was detected in DNA obtained from the tumor cells in case 1. The collective evidence suggested that these tumors underwent a central, massive apoptosis. As massive cell death similar to that seen in the present cases has been described in other documented cases of IM, we propose that the spontaneous regression that frequently occurs with this type of tumor may be mediated by massive apoptotic cell death.

Detection of Mycobacterium tuberculosis in clinical specimens by polymerase chain reaction and Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test

The polymerase chain reaction (PCR) using oligonucleotides based on the repetitive sequence (IS986) of Mycobacterium tuberculosis as a primer and the Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (MTD), which combines an M. tuberculosis rRNA amplification method with the hybridization protection assay format, were evaluated for detection of M. tuberculosis in clinical samples. The detection limits of these two assay systems based on nucleic acid amplification for cultured M. tuberculosis were less than 10 cells per reaction. A total of 135 sputum specimens were examined by the two assay systems. The PCR and the MTD systems for detection of M. tuberculosis gave overall positivity rates of 84.2% (32 of 38) and 91.9% (34 of 37), respectively, as compared with 71.9% (23 of 32) by smear and 96.9% (31 of 32) by culture in the liquid medium MB-Check. Procedures for sample preparation used in the two methods were different. Although the sensitivities of the PCR and MTD appeared to be similar to that of culture with the MB-Check system, the two methods based on nucleic acid amplification should be very useful for rapid detection of M. tuberculosis infections without the long time required for culture of M. tuberculosis.

[Anti-type II collagen antibodies in collagen disease]

Using enzyme-linked immunosorbent assay (ELISA), we determined the incidence of serum IgG antibodies to native type II collagen in patients with collagen diseases such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), progressive systemic sclerosis (PSS) and overlap syndrome (OL). Raised serum IgG anti-type II collagen antibody levels were present in 11% of patients with RA, 30% with SLE, 44% with PSS and 42% with OL. There was, however, no correlation with clinical manifestations or other laboratory data.

Restriction fragment length polymorphism analysis of epidemiologically related Mycobacterium tuberculosis isolates

Restriction fragment length polymorphism (RFLP) analysis of a large number of Japanese isolates of Mycobacterium tuberculosis, containing isolates from small outbreaks of M. tuberculosis infection, and clinical isolates of M. bovis BCG, was carried out using a DNA probe derived from the insertion sequence IS986. Clinical isolates of M. tuberculosis had a high degree of RFLP. The occurrences of the IS element varied from 1 to 19, the majority of isolates having 8 to 15 copies. Very similar fingerprints, however, were seen among strains isolated in the Kanto district. In particular, 3 strains were of the same pattern with or without an additional band. Similarity of the banding patterns of strains isolated in the same district was observed in other areas. Six groups of strains, each group arising from a suspected common source of infection, were analyzed. Of these, 5 showed identical fingerprints within each group, but one showed different fingerprints. RFLP patterns of three strains isolated from individuals with lymphadenitis developed about two months after BCG vaccination, and one strain isolated from a bladder cancer patient with BCG instillation therapy were identical to those of BCG-Tokyo which had been used for the vaccination and therapy. These results confirm that RFLP analysis using IS986 is a suitable tool for epidemiology of tuberculosis.

Comparison of MB-Check, BACTEC, and egg-based media for recovery of mycobacteria

The rate of recovery and time to the detection of mycobacteria from clinical specimens were measured for biphasic (MB-Check; Nippon Roche Co., Ltd., Tokyo, Japan) and radiometric (BACTEC; Nippon Becton Dickinson Co., Ltd., Tokyo, Japan) liquid-based culture systems and egg-based media (3% Ogawa and Ogawa K). From the 245 sputum specimens processed, a total of 86 (35.1%) mycobacterial isolates were detected. Of these, 81 (94.2%) and 80 (93.0%) isolates were detected with the MB-Check and BACTEC systems, respectively, and 65 (75.6%) isolates were detected with the 3% Ogawa egg method. The difference in the percentages of positive cultures between the two systems based on liquid media and the 3% Ogawa egg method was significant (P less than 0.01). This difference was even greater among smear-negative specimens. The detection time was shorter with the liquid-based systems. The mean times to the detection of the Mycobacterium tuberculosis complex were 19.1 days with the MB-Check system, 13.4 days with the BACTEC system, and 21.7 days with the 3% Ogawa egg method. These results indicate that both the MB-Check and the BACTEC systems, based on liquid media, are efficient for the recovery of mycobacteria.

Cloning and expression of the gene for the Avi-3 antigen of Mycobacterium avium and mapping of its epitopes

The Avi-3 antigen, which is found only in Mycobacterium avium culture sonic extracts, is species specific and results in strong skin test activity in guinea pigs sensitized with heat-killed M. avium. Its gene was cloned by using a previously developed single-probe method and was sequenced. The gene encoded a 194-amino-acid polypeptide with a molecular weight of 21,500. A recombinant Avi-3 antigen expressed in Escherichia coli reacted with monoclonal and polyclonal antibodies raised against the native Avi-3 antigen. To identify epitopes on this protein for immunodiagnostic purposes, various parts of the Avi-3 antigen were expressed as beta-galactosidase fusion proteins, using pUR and pURS expression vectors. The clones screened by both antibody reactivity and T-cell proliferative activity defined fragments with coexisting B- and T-cell epitopes. A B-cell epitope (Asn-176 to Ala-186) and two T-cell epitopes (Glu-75 to Ile-86 and Arg-155 to Leu-164) were thus defined. The synthetic polymerized peptides of the T-cell epitopes were proven to elicit a delayed cutaneous hypersensitivity reaction in guinea pigs. This mapping method would be useful in the development of a subunit vaccine consisting of an immunodominant B-cell epitope linked to a T-cell epitope in the vicinity.

Production of a monoclonal antibody specific for Mycobacterium avium and immunological activity of the affinity-purified antigen

Three hybridomas which secrete antibodies to Mycobacterium avium were obtained by the fusion of p3u1 myeloma cells with spleen cells of mice immunized with M. avium culture sonicate. The reactivity of these monoclonal antibodies was determined in 16 species of mycobacteria by an enzyme-linked immunosorbent assay. An antibody, designated Avi-3, reacted only with M. avium and not with the reference strains of the other 15 species of mycobacteria tested, including M. intracellulare, M. paratuberculosis, and M. lepraemurium. Specificity of the antibody was confirmed by assay, using a specific DNA probe of M. avium complex in 29 M. avium complex isolates. An antigen was purified from M. avium culture sonicate on a monoclonal antibody Avi-3-coupled affinity column. The purified antigen gave a single band (molecular size, about 27 kilodaltons) upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The antigen Avi-3 showed strong skin test activity in guinea pig preimmunized with heat-killed M. avium but not in those sensitized with heat-killed M. intracellulare or M. bovis BCG. Purified protein derivative elicited positive skin reactions in all the immunized guinea pigs. When heat-killed M. avium was used as the immunogen, strong lymphoproliferative responses were observed in cultures stimulated with the antigen Avi-3. These results suggest that M. avium-specific antigen Avi-3 may facilitate the diagnosis of mycobacterial infections.

Detection of a novel HLA-DQ specificity: serological and immunochemical analyses by a monoclonal antibody

A monoclonal antibody (mAb) with a novel human B-cell allospecificity was produced by immunizing a C3H/He mouse with the human B lymphoblastoid cell line EBV-Wa (HLA-DR4/Dw15/DQblank homozygous). The mAb, termed HU-46, reacted with B cells from not only DR4/Dw15-positive individuals but also certain DRw8/Dw8-positive ones whose DQ phenotypes had not yet been defined. Two-dimensional gel analyses indicated that the mAb recognized class II antigens which were encoded by the HLA-DQ locus. Furthermore, in genetic analysis, the gene encoding the class II antigen detected by HU-46 met the Hardy-Weinberg condition as a fourth allele of the DQ locus. We provisionally labeled this novel DQ specificity DQWa.

A cytotoxic monoclonal antibody (HU-39) that detects DRw8 + DRw12

A monoclonal antibody, HU-39, was produced by immunizing BALB/c mice with a cultured human B lymphoblastoid cell line, Shi-C3 (HLA-A24, A31, B51, Bw52, DR2, DRw12, DQw1, DQw3). Utilizing the complement-dependent cytotoxicity test, HU-39 was found to detect a polymorphic determinant common to HLA-DRw8 and HLA-DRw12, a split antigen of HLA-DR5. Although HU-39 reacted with the cells from all of nine DRw12 positive individuals, the cells from only 18 out of 21 DRw8 positive individuals reacted with HU-39 and the remaining three were negative for HU-39. The cytotoxicity of the antibody was reduced after the surface HLA-DR molecules of two cell lines, GI and EBV-Sh, typed as DRw8 and DRw12, respectively, were masked with F(ab')2, of anti-HLA-DR monoclonal antibody. The results of the sequential coprecipitation test and the two-dimensional gel electrophoresis by using EBV-Sh also indicated that HU-39 preferentially recognizes an epitope borne on the DR molecules, but not on the DQ molecules. Thus, HU-39 appeared to be of great value as a tissue typing reagent to define DRw8 and DRw12, the latter of which had been difficult to assign because of the lack of monospecific alloantisera.

[Human cytotoxic T cell clones that recognize HLA-DQw3 antigens]

Human cytotoxic T cell (CTL) clones generated against a DQw3-positive EBV-transformed B cell line were analyzed in terms of immunological characteristics. The cytolytic activities of clones 1-18 and 3-34 were inhibited by anti-DQw3 monoclonal antibodies (HU-18 and HU-23), but they were not affected by anti-DR (HU-4 and HU-20) and anti-HLA-A, B, C (W6/32) monoclonal antibodies. In contrast to that the clone 1-18 cytolyzed all the human B cell lines typed as DQw3, the clone 3-34 reacted only with DR4/Dw4 and DR5-positive cells that were positive for HU-23 and typed as TA10. In addition, the clone 3-34 were cross-reactive to DQw2-typed cells. These results show that there are two epitopes that CTL recognize on the same DQw3 molecules; one is the public epitope among DQw3 antigens, and the other is the private epitope that HU-23 recognizes. This is the further evidence for CTL recognition of HLA-DQ antigens.

A study on class II antigens involved in the T cell proliferative responses to PPD using cross-reacting monoclonal antibodies in human and murine system

Two monoclonal antibodies (MoAb) 1E4 and ISCR3, which detect class II antigens across species barriers, were studied for their inhibitory effects on human and murine T cell proliferative responses to purified protein derivative of tuberculin (PPD). The 1E4 detected at least a polymorphic determinant on I-A molecules from mice carrying the H-2b haplotype, and the ISCR3 detected the Ia.7 determinant on I-E molecules. Nevertheless, both 1E4 and ISCR3 recognized monomorphic determinants on HLA-DR antigens (human I-E equivalent molecules), but not on HLA-DQ antigens (human I-A equivalent molecules). It was demonstrated that 1E4 significantly inhibited PPD-specific responses of T cells from Ib-bearing mice. In contrast, ISCR3 showed marginal effects on the responses of mice bearing Ia.7. However, in the human system both 1E4 and ISCR3 reduced proliferative responses to PPD. These results suggest that a functional difference exists between humans and mice in the I subregion products involved in the T cell proliferative responses to PPD.

An AFP-producing gastric carcinoma with features of hepatic differentiation. A case report

A patient with primary gastric adenocarcinoma with extremely high serum alpha-fetoprotein (AFP) levels (12,000 ng/ml) is described. Histologically, foci strongly resembling hepatocellular carcinoma with hyaline globules were noted. Within tumor cells, AFP was identified with both light and electron microscopy, showing the production of AFP by tumor cells themselves. Furthermore, 88% of serum AFP combined with Concanavalin A (ConA), revealing that it was hepatic-type AFP and not germ-cell-type. Localization of alpha-1-antitrypsin within tumor cells was also noted. Ultrastructural study showed that there were two types of structures corresponding to periodic acid-Schiff (PAS)-positive globules, one of which, the proteinaceous material in intracytoplasmic lumina, was found to contain AFP. Among gastric adenocarcinomas with a high serum AFP level (several thousand or more ng/ml of AFP), foci resembling hepatocellular carcinomas have been reported by several investigators. Those gastric carcinomas, together with the current case, may constitute a clinicopathologic entity, hepatoid adenocarcinoma of the stomach.

An AFP-producing gastric carcinoma with features of hepatic differentiation. A case report

A patient with primary gastric adenocarcinoma with extremely high serum alpha-fetoprotein (AFP) levels (12,000 ng/ml) is described. Histologically, foci strongly resembling hepatocellular carcinoma with hyaline globules were noted. Within tumor cells, AFP was identified with both light and electron microscopy, showing the production of AFP by tumor cells themselves. Furthermore, 88% of serum AFP combined with Concanavalin A (ConA), revealing that it was hepatic-type AFP and not germ-cell-type. Localization of alpha-1-antitrypsin within tumor cells was also noted. Ultrastructural study showed that there were two types of structures corresponding to periodic acid-Schiff (PAS)-positive globules, one of which, the proteinaceous material in intracytoplasmic lumina, was found to contain AFP. Among gastric adenocarcinomas with a high serum AFP level (several thousand or more ng/ml of AFP), foci resembling hepatocellular carcinomas have been reported by several investigators. Those gastric carcinomas, together with the current case, may constitute a clinicopathologic entity, hepatoid adenocarcinoma of the stomach.

An AFP-producing gastric carcinoma with features of hepatic differentiation. A case report

A patient with primary gastric adenocarcinoma with extremely high serum alpha-fetoprotein (AFP) levels (12,000 ng/ml) is described. Histologically, foci strongly resembling hepatocellular carcinoma with hyaline globules were noted. Within tumor cells, AFP was identified with both light and electron microscopy, showing the production of AFP by tumor cells themselves. Furthermore, 88% of serum AFP combined with Concanavalin A (ConA), revealing that it was hepatic-type AFP and not germ-cell-type. Localization of alpha-1-antitrypsin within tumor cells was also noted. Ultrastructural study showed that there were two types of structures corresponding to periodic acid-Schiff (PAS)-positive globules, one of which, the proteinaceous material in intracytoplasmic lumina, was found to contain AFP. Among gastric adenocarcinomas with a high serum AFP level (several thousand or more ng/ml of AFP), foci resembling hepatocellular carcinomas have been reported by several investigators. Those gastric carcinomas, together with the current case, may constitute a clinicopathologic entity, hepatoid adenocarcinoma of the stomach.

An AFP-producing gastric carcinoma with features of hepatic differentiation. A case report

A patient with primary gastric adenocarcinoma with extremely high serum alpha-fetoprotein (AFP) levels (12,000 ng/ml) is described. Histologically, foci strongly resembling hepatocellular carcinoma with hyaline globules were noted. Within tumor cells, AFP was identified with both light and electron microscopy, showing the production of AFP by tumor cells themselves. Furthermore, 88% of serum AFP combined with Concanavalin A (ConA), revealing that it was hepatic-type AFP and not germ-cell-type. Localization of alpha-1-antitrypsin within tumor cells was also noted. Ultrastructural study showed that there were two types of structures corresponding to periodic acid-Schiff (PAS)-positive globules, one of which, the proteinaceous material in intracytoplasmic lumina, was found to contain AFP. Among gastric adenocarcinomas with a high serum AFP level (several thousand or more ng/ml of AFP), foci resembling hepatocellular carcinomas have been reported by several investigators. Those gastric carcinomas, together with the current case, may constitute a clinicopathologic entity, hepatoid adenocarcinoma of the stomach.

Inhibition of autologous mixed lymphocyte reaction by monoclonal antibodies specific for the beta chain of HLA-DR antigens

Recent studies using rabbit antisera to the separated HLA-DR alpha and beta subunits have suggested that alpha chain-specific, but not beta chain-specific, antisera inhibit T cell proliferative responses in primary and secondary human autologous mixed lymphocyte reaction (AMLR). In the present study, with the aid of sequential co-precipitation assays and Western blotting methods, a monoclonal rat alloantibody 1E4, specific for the beta chain of rat class II molecules carrying an Ia determinant Ba-2.7, was characterized to recognize a monomorphic determinant located on the beta chain of DR antigens. This antibody and a murine monoclonal antibody HU-4, also specific for the beta chain of DR antigens, strongly inhibited both primary and secondary AMLR through a mechanism distinct from an antibody-dependent cell-mediated cytotoxicity reaction. These results indicate that the inhibition of AMLR is not a unique feature of DR alpha-specific antibodies.

Metastases to the female genital tract. Analysis of 325 cases

In order to better define the frequency and patterns of metastasis to the female genital tract, all cases of nonhematopoietic metastases to the adnexa, uterus, vagina, and vulva encountered in patients treated at Barnes Hospital between 1950 and 1981 were reviewed. Three hundred twenty-five metastatic cancers from 269 patients were recovered. One hundred forty-nine cases were from extragenital primaries; the remaining tumors were intragenital metastases. Ovary and vagina were the most frequent metastatic sites for both extragenital and genital primaries. The majority of the extragenital metastases were adenocarcinomas from the gastrointestinal tract, but a variety of other primaries did spread, on occasion, to the genital tract. Twenty-seven percent of the metastases presented as possible primary gynecologic lesions, and 75% of these tumors had an extragenital origin. It is shown that despite certain trends in the distribution of metastases, all sites in the female genital tract are at risk for the occurrence of metastases.