Paclitaxel enhances antibody-dependent cell-mediated cytotoxicity of trastuzumab by a rapid recruitment of natural killer cells in Her-2 overexpressing breast cancer

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Background: One of the important mechanisms that trastuzumab (TZ) inhibits the growth of Her-2 overexpressing breast cancer cells is the activation of a host tumor response via antibody-dependent cell-mediated cytotoxicity (ADCC). Although paclitaxel (PTX) has a synergistic effect in combination with TZ, whether the ADCC is enhanced by PTX is less known. We questioned whether adding PTX to TZ enhances ADCC and also investigated kinetics of effector cells in ADCC. Methods: Twenty-eight patients with Her-2 overexpression, 9 received the combination of (4mg/kg as a loading and 2 mg/kg weekly) and PTX (80 mg/m2 weekly) and 19 did monotherapy of TZ, were studied. Using blood samples (mononuclear cells) taken before and 10 minutes after administrations, ADCC and the number of effector cells including NK cell, monocyte, and CD64+ cell were compared in each case (after/before). ADCC was analyzed by 51Cr releasing assay using SK-BR-3 cell line and the fractions of NK cells (both CD16+(FcγRIII) and CD56+) and CD64+(FcγRI) cells were analyzed by flow cytometry. Results: ADCC levels increased in + 9% (mean) after TZ monotherapy and + 120% (p<0.05) after the combination of TZ and PTX. All 9 patients in combination had enhancements in ADCC levels. As regards effector cells, NK cells increased in + 51% after TZ alone and in + 112% (p<0.05) after the combination. No significant changes were found in monocytes (+ 39%) and CD64+ cells (+ 53%) after TZ, however monocytes decreased in - 40% (p<0.05) and also CD64+ in - 24% after the combination. Conclusions: Adding PTX to TZ significantly enhanced ADCC, which level was twice as strong as TZ monotherapy, by a rapid recruitment of NK cells. This may reflect that a combination of TZ and PTX has a strong synergistic effect than we expected in Her- 2 overexpressing breast cancer.

No significant financial relationships to disclose.

Lipomembranous changes and calcification associated with systemic lupus erythematosus

Lipomembranous changes are histological findings without specific clinical correlations, and are thought to be related to vascular impairment in fatty tissue. We describe a case of systemic lupus erythematosus (SLE) in which subcutaneous induration of the lower leg showed lipomembranous changes and calcification. This patient showed thrombophilia with thrombosis of the femoral and iliac veins, and cerebellar and myocardial infarction. A biopsy specimen from the subcutaneous tissue surrounding the multiple leg ulcers revealed degeneration of fat cells, lipomembranous changes in the fatty tissues, and calcification. Another biopsy specimen from the outer edges of the ulcers showed microthrombi and fibrinoid changes in the vessel walls, and mononuclear cell infiltrates in the dermis. Lipomembranous changes have been seen in connective tissue disorders such as lupus profundus, morphoea, systemic sclerosis, and panniculitis associated with dermatomyositis, but rarely associated with SLE. We speculate that ischaemic changes due to the vascular disturbance of the lower legs may have induced lipomembranous changes and calcification in the subcutaneous tissues in the present case.

Impaired insulin signaling in the liver of transgenic rats with low circulating growth hormone levels

GH is known to regulate glucose and lipid metabolism as well as body growth. Controversy exists as to whether GH-deficient adults are indeed insulin sensitive or insulin resistant. In GH-deficient animal models, however, no clear observation indicating insulin resistance has been made, while increased insulin sensitivity has been reported in those animals. We have produced human GH (hGH) transgenic rats characterized by low circulating hGH levels and virtually no endogenous rat GH secretion. Although the body length of the transgenic rat is normal, they develop massive obesity and insulin resistance, indicating that the transgenic rat is a good model for the analysis of insulin resistance under GH deficiency. In this study, we have examined how GH deficiency affects the early steps of insulin signaling in the liver of the transgenic rat. Circulating glucose and insulin concentrations were significantly higher in the transgenic rats than in their littermates. In addition, impaired glucose tolerance was observed in the transgenic rat. The amount of insulin receptor was smaller in the liver of the transgenic rat, resulting in decreased tyrosine phosphorylation in response to insulin stimulation. The amounts of insulin receptor substrate-1 and -2 (IRS-1 and -2) and insulin-stimulated phosphorylation of IRSs were also smaller in the transgenic rat. Despite the decrease in tyrosine phosphorylation levels of IRSs being mild to moderate (45% for IRS-1 and 16% for IRS-2), associated phosphatidylinositol 3-kinase (PI3-kinase) activity was not increased by insulin stimulation at all in the transgenic rat. To elucidate whether this discrepancy resulted from the alteration in binding of the p85 subunit of PI3-kinase to phosphotyrosine residues of the IRSs, we determined the amount of p85 subunit in the immunocomplexes with anti-phosphotyrosine antibody. Insulin did not affect the amount of p85 subunit associated with phosphotyrosine in the transgenic rats, while it significantly increased in the controls, indicating that alteration may have occurred at the sites of phosphorylated tyrosine residues in IRSs. These results suggest that GH deficiency in the transgenic rat leads to impairment in at least the early steps of insulin signaling in the liver with a resultant defect in glucose metabolism.

Detection of transgene in progeny at different developmental stages following testis-mediated gene transfer

We recently reported that exogenous DNA injected into testis as a liposome complex can be transferred into the egg via sperm by natural mating and integrated in the genome (testis-mediated gene transfer: TMGT). Here, we studied the efficiency of each of the several liposomes in associating foreign DNA with sperm, the expression of an introduced gene in early embryos, and the presence of the DNA in fetuses and pups at different ages. The CMV/beta-actin/EGFP fusion gene, encapsulated with different liposomes, was injected into rat testis, and spermatozoa in the cauda epididymis were obtained 1, 4, and 14 days after injection. We tested each of the 8 liposomes, and found that only 2, DMRIE-C and SuperFect, led to the detection of foreign DNA on all of the days examined, with relatively higher ratios of rats having positive sperm. By means of TMGT using either of those two liposomes, more than 80% of morula-stage embryos expressed EGFP, as observed by fluorescence microscopy. Then we detected introduced DNA in the progeny by PCR and Southern dot blot, and found that the ratio of animals carrying the foreign DNA decreased as they developed, and that only a part of postpartum progeny were foreign-DNA-positive with high incidence of mosaicism. These results suggest that, although, the success rate is still limited, foreign DNA could be integrated into the genome of the progeny by TMGT at least under specific experimental conditions, the efficiency of which depends largely on the characteristics of the liposome. The results also suggest that TMGT could be applicable to fetal gene therapy as well as to the generation of transgenic animals.

Development of obesity in transgenic rats with low circulating growth hormone levels: involvement of leptin resistance

BACKGROUND

Human growth hormone (hGH) transgenic (TG) rats have been produced in our laboratory. These TG rats are characterized by low circulating hGH levels, virtually no endogenous rGH secretion, and massive obesity.

OBJECTIVE

To elucidate how energy balance and leptin sensitivity contributed to the establishment of this obesity.

DESIGN AND METHODS

Food intake, locomotor activity and leptin concentrations in serum and cerebrospinal fluid were measured in TG rats and their non-transgenic littermates (control). The effect of intraperitoneal and intracerebroventricular injection of leptin on food intake and body weight gain was also examined.

RESULTS

An increase in food intake and a decrease in locomotor activity were observed from 4 and 7 weeks of age, respectively, in the transgenic rats compared with control. Serum leptin concentrations of the transgenic rats were more than twice as high as those of control rats and were associated with an increased white adipose tissue mass and ob gene expression. Intraperitoneal injection of leptin significantly decreased food intake and body weight gain in control rats, but not in transgenic rats. Leptin concentration in the cerebrospinal fluid of transgenic rats was not different from that of control rats, and intracerebroventricular injection of leptin was similarly effective in reducing food intake and body weight gain as it was in control rats.

CONCLUSIONS

These results suggest that the transgenic rats, whose GH secretion is suppressed, develop obesity due to early onset of an increase in food intake and a decrease in locomotor activity with leptin resistance resulting from deteriorating leptin transport from peripheral blood to cerebrospinal fluid.

Telomerase activity significantly correlates with chromosome alterations, cell differentiation, and proliferation in lung adenocarcinomas

Telomerase activity was examined by the telomeric repeat amplification protocol assay in 25 cases of lung adenocarcinoma, in relation to cancer cell differentiation, proliferation, and chromosome alterations. Telomerase activity, chromosome alterations, and cell proliferation assessed by Ki-67 labeling were significantly lower (P < .001 to .05) in well-differentiated (10 cases) than in moderately differentiated (8 cases) or poorly differentiated (7 cases) lesions. Telomerase activity by semiquantitative analysis with scoring of 0 to 3 was significantly correlated with similarly graded chromosome alterations (P < .05) and Ki-67 labeling indices (P < .002). Telomerase activity and chromosome alteration (T-C) indices generated by multiplication of telomerase activity and chromosome alteration scores also showed a significant correlation with cell differentiation. The Clara cell subtype, confirmed by electron microscopic analysis, significantly predominated in the well-differentiated group, showing a low grade of telomerase activity and chromosome alterations and low Ki-67 labeling indices, suggesting clinical relevance. No significant association of telomerase activity was found with p53 protein accumulation or Bcl-2 protein expression. The good correlation of telomerase activity with chromosome alterations, cell differentiation, and Ki-67 labeling indices suggests that this parameter might have potential application in estimation of prognosis.

Requirement of the Fas ligand-expressing luteal immune cells for regression of corpus luteum

Apoptosis in corpus luteum (CL) is induced by prolactin (PRL) in female rats. PRL-induced apoptosis in CL is mediated by the Fas/Fas ligand (FasL) system. The CL consists of steroidogenic and non-steroidogenic cells, including immunocytes. Fas mRNA was detected only in the luteal steroidogenic cells, and FasL mRNA was expressed only by the non-steroidogenic CD3-positive luteal immunocytes. Removing the luteal immune cells from the luteal cells inhibited PRL-induced luteal cell apoptosis effectively. Thus, FasL-expressing non-steroidogenic luteal immunocytes are required for PRL-induced luteal cell apoptosis and heterogeneous induction of apoptosis by Fas/FasL in CL.

Suppression of copulatory behavior by intracerebroventricular infusion of antisense oligodeoxynucleotide of granulin in neonatal male rats

Sexual dimorphism of the rodent brain is manifested by the epigenetic action of gonadal steroids. Our previous research identified the granulin (grn) precursor gene as a sex steroid-inducible gene, which was shown to be expressed more abundantly in male than female neonates at the mediobasal hypothalamic area. Grn is a 6-kDa polypeptide promoting or inhibiting the growth of epithelial cells and hematocytes in vitro. In this study, effects on male sexual behavior of male were pursued under conditions in which grn gene expression was suppressed during the critical period. To this end, an antisense oligodeoxynucleotide (ODN) of the grn precursor gene was designed, incorporated into inactivated Sendai virus (HVJ)-liposome complexes, and infused into the third ventricle of 2-day-old male rats. Two different control treatments were used: the first consisted of a control sequence ODN that had little homology to known mRNAs; the second of vehicle (HVJ-liposome) alone. After maturation, animals treated with antisense ODN of grn displayed significantly lower scores than control males on various parameters assessing sexual behavior; i.e., mount, intromission, and ejaculation. The antisense ODN, however, did not affect body growth or serum concentrations of testosterone and luteinizing hormone. Further, there was no significant difference in the volume of the sexual dimorphic nucleus of the preoptic area between antisense ODN-treated and control animals. It was shown that inadequate expression of the grn gene in the brain of male neonatal rats during the critical period suppressed the induction of some type of male sexual behavior, suggesting the grn was involved in the process of masculinization of the rat brain.

Characterization of hepatic cytochrome P450 isozyme composition in the transgenic rat expressing low level human growth hormone

1. The present authors have previously developed a transgenic rat carrying a chimeric gene of the mouse whey acidic protein promoter and the structural portion of human growth hormone (GH) gene. Among this (hGH-TG) rat, a line (low GH rat) missing a male-specific pulsatile GH secretary pattern due to suppression of endogenous GH secretion and having a continuous low GH (hGH and rat GH) level in the peripheral circulation was identified. The latter rat was also characterized as having severe obesity with age. This strain (low Gh rat) was used to correlate the sex-specific secretory pattern of GH with the sex-specific expression of cytochrome P450 (CYP) in rat. 2. Comparisons were made between the low GH rat and the non-transgenic rat as to the expression of liver microsomal CYP isozymes. The following enzyme activities were assessed: testosterone (T) hydroxylation and oxidation; ethoxyresorufin O-dealkylation (EROD); bunitrolol (BTL) 4-hydroxylation and T5 alpha-reduction. Protein expression of CYP1A, CYP2C11, CYP2D, CYP2E1, CYP3A2 and CYP4A1 were also assessed by Western blot analysis. 3. Enzyme activities and protein expression of CYP2C11 (T16 alpha and 2alpha-hydroxylase and 17-oxidase activities) and CYP3A2 (T6beta and 2beta-hydroxylase activities) levels, which are known to be higher in the male than in the female rat, were significantly lower in the adult male low GH rat than in the control male rat. In contrast, CYP2A1 (T7 alpha-hydroxylase) and T5-alpha-reductase activities, which are known to be specifically elevated in the female, were significantly higher in the adult male low GH rat than in the control male rat. Thus, the loss of male-specific secretory pattern of GH results in feminization of the pattern of expression of CYP and T5 alpha-reductase activity in the liver. 4. In contrast to other GH-deficient models so far studied, an increase in CYP4A1 and a decrease in CYP2E1 protein expression were observed in the low GH rat. These trends are consistent with the characteristic phenotype of obesity in the transgenic rat because CYP4A1 and CYP2E1 enhance fatty acid excretion and glyconeogenesis from fatty acids respectively.

An immunohistochemical study of the mesenchymal and epithelial components of pulmonary chondromatous hamartomas

Twenty-five cases of solitary pulmonary chondromatous hamartomas (PCH) were examined by immunohistochemistry to evaluate the mesenchymal and epithelial components. PCH composed of predominantly mature cartilage were designated as C type, those predominantly composed of fibromyxoid tissue as FM type, and those predominantly composed of adipose tissue as A type. FM type PCH revealed various amounts of cartilage in various developmental stages, adipose tissue and fibromyxoid tissue, compared with a uniform pattern of cartilage tissue in C type. The cells of transitional form between spindle cells, stellate cells and chondrocytes were present in FM type. Epithelial components in PCH were bronchial, bronchiolar and cuboidal cells, mostly at the periphery of PCH. S-100 protein consistently stained chondrocytes, stellate and spindle cells in the fibromyxoid tissue of solitary PCH. Fibroblast growth factor was immunolocalized to chondrocytes, spindle and stellate cells in the fibromyxoid tissue. The collagen type was associated with differentiation from primitive mesenchymal cells to chondrocytes (i. e. type I and III collagen appeared in fibromyxoid matrix and type II collagen in the cartilaginous matrix). Fibronectin coordinately appeared with type I and III collagens. The proliferating cell nuclear antigen labeling index of epithelial cells was comparable to those of neoplastic mesenchymal cells, but it was not significantly different between C type and FM type PCH. The primitive mesenchymal cells in the bronchial walls of the control premature neonates were also observed. This immunohistochemical study showed that the progenitor mesenchymal cells in the bronchial and bronchiolar walls may differentiate along chondrocytes, lipocytes, and smooth muscle cells in PCH and that epithelial proliferation is reactive and closely associated with neoplastic proliferation of the mesenchymal component.

Characterization of a novel member of the FGF family, XFGF-20, in Xenopus laevis

The cDNA for a novel member of the FGF family (XFGF-20) was isolated from a Xenopus cDNA library prepared at the tailbud stage using as a probe the product of degenerate PCR performed with primers based on mammalian FGF-9s. This cDNA was 1860 bp long, and contained a single open reading frame that encoded 208 amino acid residues. The deduced amino acid sequence contained a motif characteristic of the FGF family and it was similar (73.1% overall homology) to XFGF-9 but differed from XFGF-9 in its amino-terminal region (33.3% homology). XFGF-20 mRNA was expressed only zygotically in embryos at and after the blastula stage, but it was also specifically expressed in the stomach and testis of adults. By contrast, XFGF-9 mRNA was expressed maternally in eggs and in many adult tissues. When XFGF-20 mRNA was overexpressed in early embryos, gastrulation was abnormal and development of anterior structures was suppressed. In such embryos, the expression of the Xbra transcript was suppressed during gastrulation while the expression of the transcripts of cerberus, Siamois, dkk-1, chordin, and Xotx-2 genes was normal. These results suggest that correct expression of XFGF-20 during gastrulation is required for the formation of normal head structures in Xenopus laevis during embryogenesis and that expression of the Xbra gene mediates this phenomenon.

Experience and clinical usefulness of BACTEC MGIT 960

Recently, an automatic instrument for culturing acid-fast bacteria in liquid media has been introduced in Japan to accelerate and increase the detection of the bacteria as well as the work e ciency of test lab technicians. We compared the MGIT (Mycobacterium Growth Indicator Tube) method and the two conventional culture methods used in our lab by testing 176 specimens (130 cases) submitted for acid-fast testing between July 27 and September 18, 1998. BACTEC MGIT 960 (Nippon Becton Dickinson) was used in the MGIT method while Ogawa K medium and Kudo PD medium were used for our conventional culture methods. Of the 176 specimens, 26 specimens were MGIT positive, 22 specimens were Ogawa K medium positive, and 21 specimens were Kudo PD medium positive. Among these three culture methods, M. tuberculosis was found in 8 specimens, M. avium was found in 9 specimens, M. intracellulare was found in 4 specimens, and other acid-fast bacteria were found in 5 specimens. It took an average of 13.5 days to detect M. tuberculosis by the MGIT method, 23.0 days by the Ogawa K medium, and 24.3 days by the Kudo PD medium, suggesting that the MGIT method is signi cantly faster than the conventional methods (p < 0.05). The MGIT method took an average of 5.7 days to detect M. avium and M. intracellulare while the two conventional methods required more than 20 days, suggesting that the MGIT method is signi cantly faster than the conventional methods (p < 0.05). The BACTEC MGIT 960 was extremely useful for clinical diagnosis in some of the cases and our results indicated that the MGIT method led to more rapid diagnosis and earlier treatment than the conventional methods.

[Spontaneous esophageal rupture after gastrointestinal examination using barium]

We experienced a case of spontaneous rupture of the esophagus after gastrointestinal examination using barium. A 48-year-old male experienced severe chest pain after vomiting following gastrointestinal examination. Chest X-ray revealed a right pneumothorax and pleural effusion by barium. We diagnosed spontaneous rupture of the esophagus and performed right thoracotomy 6 hours after onset of symptoms. At 10 cm above the diaphragm, there was a vertical perforation 3 cm in length. Following saline lavage, the ruptured esophageal wall was directly closed by the layer to layer method. The post operative course was uneventful and the patient was discharged 3 weeks after surgery. Cases of spontaneous rupture of the esophagus into the right thoracic cavity induced by gastrointestinal examination are extremely rare.

Obesity and insulin resistance in human growth hormone transgenic rats

A line of transgenic rats (heterozygotes) carrying a chimeric gene comprising a regulatory portion of murine whey acidic protein and a structural portion of human GH (hGH) genes developed severe obesity with age. To characterize physiological mechanisms that lead to fat accumulation, an array of parameters related to obesity were studied. Blood hGH levels were continuously low, endogenous rat GH secretion was suppressed, and the pulsatility in peripheral GH levels was absent. Plasma glucose, insulin, triglyceride, and FFA levels in the male transgenic rats significantly exceeded those in nontransgenic littermates at 12 and 17 weeks, but not at 7 weeks, of age. All symptoms except hyperlipidemia were restored to normal by treatment with an antidiabetic agent, thiazolidinedione (troglitazone), for 1 week from 17 weeks of age. As phenotypic expression of obesity was already evident before aberration of physiological parameters, it was assumed that animals had a condition in which obesity or hyperlipidemia caused hyperinsulinemia. Gene expression and enzymatic activity of lipoprotein lipase in the adipose tissue in the transgenic rats were not different from those in normal rats. In contrast, the gene expression level of glycerol-3-phosphodehydrogenase was markedly elevated, suggesting that glycerol synthesis was much enhanced in the adipocytes of the transgenic rats. In an i.p. glucose tolerance test, the transgenic rats were not hyperglycemic at 7 weeks of age; however, the animal became hyperglycemic at 15-17 weeks of age. Finally, treatment with recombinant hGH for 1 week to produce pulsatile secretion reduced the size of epididymal and kidney fat pads and restored normal weight gain. These observations suggest that continuously low peripheral GH levels with the lack of pulsatile secretion resulted in obesity and noninsulin-dependent diabetes mellitus.

A novel method for making nested deletions and its application for sequencing of a 300 kb region of human APP locus

We developed a novel in vitro method for making nested deletions and applied it to a large-scale DNA sequencing. A DNA fragment to be sequenced (up to 15 kb long) was cloned with a new vector possessing two unique Sfi I sites, digested by Sfi I and ligated to generate a large head-to-tail concatemer. The large concatemer was randomly fragmented by sonication and then redigested by Sfi I to separate insert and vector DNAs. The fragments of various length were then cloned into the other vector(s) specifically designed for selective cloning of insert-derived DNA fragments to generate a library of nested deletions. This method allowed a single person to generate >20 nested deletion libraries sufficient to cover 100 kb in a few days. We applied the method for sequencing of P1 clones and successfully determined the complete sequence of approximately 300 kb of the human amyloid precursor protein (APP) locus on chromosome 21 with a redundancy of 3.8, reasonably low cost and very few gaps remaining to be closed. Development of some new instruments and software is also described which makes this method more applicable for large-scale sequencing.

[Two cases of a solitary fibrous tumor with different growth patterns]

We report two cases of a solitary fibrous tumor demonstrating different growth patterns. Case 1: a 46-year-old male presented with a pedunculated solid tumor which was found between the lobes projecting from the lingula lobe. Case 2: a 68-year-old female demonstrated a tumor, measuring 2 cm in size, clearly inside the lung. The tumor was covered with pleura and could be removed bluntly. Histopathologically, spindle shaped fibroblasts were uniformly distributed in abundant, tangled collagen fibers in both cases. Sinusoid-like lumens, lined with one endothelium layer were also found. Immunohistological staining was strongly positive for vimentin and CD34, while it was negative for keratin, cytokeratin and EMA. The diagnosis of a pedunculated solitary fibrous tumor which extruded to outside the lung was made in one case, while in the other case a solitary fibrous tumor proliferating inside the lung was diagnosed. Many investigators have suggested this type of tumor to derive from mesenchymal tissue under mesothelium cells and is thus probably different from diffuse mesothelioma.

Local Control and Cosmetic Outcome after Sector Resection with or without Radiation Therapy for Early Breast Cancer

Breast conserving surgery and radiation therapy (RT) can achieve a more favorable cosmetic outcome than mastectomy in patients with early breast cancer. However, it is widely recognized that RT is an impediment to improving the cosmetic outcome. Between 1985 and 1993, 113 patients were enrolled in a prospective randomized study to examine whether or not RT could be avoided following sector resection in patients with Stage I and II (UICC) invasive breast cancer. There was no significant difference in the 8 year local recurrence free survival rate between the RT and non-RT groups (92.3% versus 89.8% respectively). The characteristics of suitable patients would be negative nodes and microscopically negative resection margins. In conclusion, sector resection without RT is a reasonable option for some patients with early breast cancer.

Flow cytometric analysis of the DNA content of adenocarcinoma of the lung, especially for patients with stage 1 disease with long term follow-up

BACKGROUND

To assess the prognostic value of DNA ploidy in adenocarcinoma of the lung, the authors performed a flow cytometric study using paraffin embedded archival material from 160 patients (109 [68%] with aneuploid lesions, 51 [32%] with diploid lesions) who underwent surgical resection from 1982 to 1991.

METHODS

The proportion of DNA aneuploid tumors increased as the disease stage advanced, from 35 of 63 (55.5%) with Stage 1 disease to 15 of 20 (75.0%) with Stage 2 disease, to 40 of 53 (75.5%) with Stage 3a disease, to 19 of 24 (79.2%) with Stage 3b disease. However, this trend was not statistically significant. Comparison of the survival time of the 160 patients with adenocarcinoma of the lung with a median follow-up of 7.8 years revealed that patients with diploid tumors had significantly longer survival than did those with aneuploid tumors (P < 0.01).

RESULTS

Examination by stage showed that patients with Stage 1 disease with diploid tumors had significantly longer survival times than did those with aneuploid tumors (P < 0.05) but that there were no significant differences in clinical outcome in patients with Stage 2, 3a, and 3b diploid tumors.

CONCLUSIONS

Analysis of aneuploid versus diploid DNA content in patients with Stage 1 adenocarcinoma of the lung is concluded to be useful in evaluating clinical outcome and prognosis.

Primary pulmonary-artery sarcoma. Report of a case with complete resection and graft replacement, and review of 47 surgically treated cases reported in the literature

A case of pulmonary leiomyosarcoma originating in the left pulmonary artery stem in a 28-year-old Japanese man is reported. The patient complained of recurrent hemoptysis. The diagnosis was made at exploratory thoracotomy. Two days following thoracotomy, under cardio-pulmonary bypass, the upper one-third of the pulmonary trunk and part of the right pulmonary artery stem were resected and left pneumonectomy was performed. A Dacron prosthetic 23 mm composite graft was inserted to replace the pulmonary trunk and a portion of the right pulmonary artery. Postoperative course was uneventful. The patient died about 8 months after surgery because of right lung metastases. In our review of surgically treated forty-eight cases, complete resection was performed in 11, incomplete resection in 23, and embolectomy in 6, whereas 8 were unresectable. A localisation often not allowing adequate resection of the tumor or the advanced stage of the tumor at surgery are considered the main causes of the poor prognosis of the pulmonary sarcoma.

[Cellular schwannoma of the lung]

A case of cellular schwannoma of the lung in 31 years-old Japanese male is presented in this paper. Cellular schwannoma differs from classic schwannoma in several histologic features. In addition, it has often been misdiagnosed as malignancy, though White's follow-up study confirmed its benign nature. It usually originates from the retroperitoneum and posterior mediastinum. No case originating from the lung has been reported in the world literature. Cellular schwannoma has to be added to differential diagnosis of the lung tumors.

Identification of an internal cis-element essential for the human L1 transcription and a nuclear factor(s) binding to the element

L1 (LINE-1) is a long interspersed repetitive sequence derived from a retrotransposon. Transfection studies using the CAT gene as a reporter demonstrated that the first 155bp in the human L1 sequence contains an element(s) responsible for the promoter activity in HeLa cells. The transcription was shown to initiate at the first nucleotide of the L1 sequence in the transgene. Three prominent nuclear protein binding sites were found in the 5' region of the L1 sequence by DNaseI footprint analysis. One of the binding sites, designated as site A located at +3 to +26, was shown to be essential for the L1 transcription because the mutation at the site A caused almost complete loss of the promoter activity. A sequence AAGATGGCC at +11 to +19 in the site A was defined as a target core element for the protein binding. The site A-binding protein (designated TFL1-A) was found in various types of cells including an embryonic teratocarcinoma cell line. These results indicate that an internal short element located at the very 5' terminal of L1 sequence and the nuclear factor binding to the element play a crucial role in the transcription of human L1.

[Preoperative diagnosis of a thoracic duct cyst arising in the supraclavicular fossa--surgical case report]

The incidence of cysts of the thoracic duct is very low, and they are reported to account for only 0.0005-0.5% of all mediastinal tumors. As far as we have been able to determine, there have been no more than 24 case reports of the surgical resection of such cysts, including our own. Moreover, lesions of the left supraclavicular fossa as in the present case were noted in only 2 reports from Western countries, and 2 cases can be found in the Japanese literature. We encountered a case of thoracic duct cyst where we were able to make a diagnosis preoperatively by means of needle aspiration, and report it here together with a discussion of the relevant literature. The patient was a 64-year-old woman who was admitted with the chief complaint of pain in the throat and a sense of pressure in the neck. A swelling was noted in the patient's left supraclavicular fossa, and when this was aspirated it yielded approximately 15 cc of yellowish-white, chylous fluid. No hoarseness or dysphagia were noted. CT scan of the thorax revealed a smooth-surfaced tumor extending from the left supraclavicular fossa to the anterior mediastinum. It showed the simple cystic lesion. On the basis of these findings, a diagnosis of thoracic duct cyst arising in the left supraclavicular space was made. Following excision, the patient's postoperative course was favorable.

[Primary pulmonary hemangiopericytoma]

Hemangiopericytoma seldom originates from the lung. Only 63 cases in the English literature and 30 cases in the Japanese literature have been reported. A 38-year-old female is presented in this paper. The patient was asymptomatic and was found a coin lesion of the left middle lobe by routine examination. She underwent tumorectomy and has been alive and well for 5 years. 1) The differential diagnosis of hemangiopericytoma from several other tumors is often difficult, as pericytes show no distinctive features on light microscopy. Therefore, it is emphasised that EM studies are obligatory to confirm the diagnosis of this tumor. 2) The origin of vessels with a characteristic staghorn appearance on light microscopy have not been described in previous papers. Bronchial arteriography in this case revealed that tumor vessels arose mainly from the bronchial artery.