Relationship of Serum Carnitine Level with Falls and Gait Disturbance in the Elderly

BACKGROUND

Gait disturbance and falls are serious events that can impair activities of daily living (ADL) in the elderly. On the other hand, carnitine plays essential roles in energy production, and carnitine deficiency leads to low activity levels.

OBJECTIVES

We examined whether a lower serum carnitine concentration was correlated with falls and gait disturbances in the elderly.

DESIGN, SETTING, AND PARTICIPANTS

We performed a cross-sectional study. One hundred and ninety-eight elderly patients (male, 83; female, 115; 81 ± 6 years old) were enrolled in this study.

MEASUREMENTS

Physical performance (hand grip strength, leg strength, walking speed, one-leg standing time, and tandem gait steps) and frailty status (The Edmonton Frail Scale: EFS) were evaluated. The serum total, free, and acylated carnitine levels were measured using an enzyme cycling method. We then investigated the associations between the serum carnitine level, history of falls, and the results of these physical examinations.

RESULTS

Of the 198 subjects, 56 (28%) had a history of falls within the past one year. The patients with a history of falls had lower serum total carnitine and free carnitine levels than those without a history of falls. Regarding the physical performance results, the patients with a history of falls had higher EFS scores, a weaker hand grip strength, a slower walking speed, a shorter one-leg standing time, and a smaller number of tandem gait steps than those without a history of falls. A logistic regression analysis showed that the low serum total carnitine concentration was identified as an independent factor associated with a history of falls, a slow walking speed after adjustments for age, sex and modified EFS.

CONCLUSIONS

A low serum carnitine level is associated with a history of falls and gait disturbances in elderly people.

Synthesis and Properties of Ferromagnetic Bulk Amorphous Alloys

Since an amorphous phase in Au-Si system was synthesized for the first time by rapid solidification in 1960[1], a large number of amorphous alloys have been prepared by various rapid solidification techniques. As the main amorphous alloy systems, one can list up the noble metal-, Fe-, Co-, Ni-, Ti-, Zr-, Nb-, Mo-, lanthanide(Ln)-, Al- and Mg-based alloys. Among these alloy systems, Fe-[2], Co-[2] and Al-[3]based amorphous alloys have been used in application fields of magnetic and high specific-strength materials. Thus, Fe- and Co-based amorphous alloys have gained the most important position as engineering amorphous alloys. When special attention is paid to Fe-based amorphous alloys, Fe-P-C alloys were synthesized in 1967[4] as the first Febased amorphous alloy. Subsequently, engineering important (Fe,Co)-Si-B amorphous alloys have been developed in 1974[5][6], followed by the formation of (Fe,Co,Ni)-(Cr,Mo,W)-C in 1978[7], (Fe,Co,Ni)-(Zr,Hf) in 1980[8] and then (Fe,Co,Ni)-(Zr,HfNb)-B amorphous alloys in 1981[9]. The (Fe,Co)-Si-B amorphous alloys have been used in many application fields as soft magnetic materials[2]. However, after 1981, nobody have succeeded in finding a new amorphous alloy in Fe- and Co-based systems by rapid solidification from liquid phase. Besides, all these amorphous alloys have serious disadvantages that high cooling rates above 105 K/s are required for glass formation and the resulting sample thickness is limited to less than about 50 μm[ 10]. Great efforts have been devoted to find Fe- and Co-based amorphous alloys with a high thermal stability of supercooled liquid against crystallization and a high glass-forming ability (GFA). Very recently, we have succeeded in finding new ferromagnetic bulk amorphous alloys with critical sample thicknesses ranging from I to 15 mm in Fe-(AI,Ga)-(P,C,B,Si)[11]-[14], (Fe,Co,Ni)-(Zr,IHf,Nb)- B[15]-[17], (Fe,Co)-(Zr,Hf)-(Nb,Ta)-(Mo,W)-B[18], (Fe,Co)-Ln-B[19] (Ln=lanthanide metal) and (Nd,Pr)-Fe-Al[20]-[22] systems. In this review, we present the formation, thermal stability, mechanical strength and magnetic properties of these new ferromagnetic bulk amorphous alloys.

Incidence of Carboplatin-related hypersensitivity reactions in Japanese patients with gynecologic malignancies

Carboplatin is one of the most commonly used and well-tolerated agents for gynecologic malignancies. The rate of hypersensitivity reactions (HSRs) in the overall population of patients receiving carboplatin has been reported to increase after multiple doses of the agent. We retrospectively analyzed the incidence, clinical features, management, or outcome of carboplatin-related HSRs in 113 Japanese patients with gynecologic malignancies and the possibility of rechallenge with the drug. We intravenously administered carboplatin after paclitaxel or docetaxel. Mild HSRs are resolved by temporary interruption of carboplatin infusion, an additional antihistamine, and/or a corticosteroid. If HSRs arose, carboplatin was diluted, not exceeding 1 mg/mL, and slowly infused over 2 hours in subsequent cycles. Ten patients experienced carboplatin HSRs, with an overall incidence of 8.85%. The first HSR episode was mild in all cases. When retreated with carboplatin, 4 exhibited severe HSRs. More than 9 cycles and/or more than 5000 mg of carboplatin administration significantly increased the incidence of HSRs. In particular, carboplatin treatment beyond 15 cycles and/or 8000 mg increased the risk of severe HSRs (P < 0.0001). The incidence of HSRs in the ovarian carcinoma group was significantly greater than that in the uterine carcinoma group (P = 0.0046). Careful attention should be paid to HSRs during carboplatin treatment beyond 9 cycles and/or 5000 mg. The rate of severe HSRs greatly increases beyond 15 cycles and/or 8000 mg. Further studies are needed to identify potential risk factors that may contribute to the development of carboplatin HSRs and to decrease the risk of reactions.

Phase I-II trial of irinotecan (CPT) and cisplatin (P) as concurrent chemo-radiotherapy (CCRT) for patients (pts) with primary local advanced cervical cancer (LACC): A KCOG 0328 trial

15002

Background: Though CCRT based on P is now recommended in LACC, there is no standard regimen. We conducted a phase I-II trial of CPT and P as CCRT in pts with primary LACC. Methods: Eligibility criteria: histologically confirmed primary LACC as FIGO stage III to IVb by para-aortic lymphnode (PAN) metastasis, age 16–75 years, ECOG performance status <2, adequate bone marrow, hepatic and renal function, and written informed consent. Radiotherapy (RT) consisted of external beam 5040cGy in 28 fractions followed by single application brachytherapy, delivering 1800–2400 cGy to point A in 3–4 fractions. The doses of chemotherapy (CT) were set up as follows: dose level (DL) 0; CPT 20 mg/m2, P 30 mg/m2, DL1; CPT 25mg/m2, P 30 mg/m2, DL2; CPT 30 mg/m2, P 30 mg/m2, and the starting level was chosen DL1. CT was curried out weekly 5 cycles concurrently with RT. Toxicities were assessed according to NCI-CTC ver2.0J and responses were assessed according to RECIST. Results: So far 9 pts have been entered. The median age was 52 years (range 29 -73). All pts were FIGO stage IIIb and histrogically squamous cell carcinoma. Among the first 2 pts in DL1, 2 dose-limiting toxicities (DLT) were observed (delay of treatment due to grade 3 diarrhea and nausea) resulting in dose reduction to DL0. In the next 3 pts in DL0, no DLTs were observed and the study is ongoing as phase II. All pts were evaluable for response and toxicity. Eight complete (CR) and 1 partial response (PR) were seen at target region of cervix. But 2 pts showed progressive disease (PD) at non-target region of PAN, lung and liver, then overall response rate assessed by RECIST was 77.8% (CR 7, PD 2). Now the median follow up period is 16 months (range 6 -30). So far 2 pts of PD died and 3 pts relapsed. The median survival time is 10+ months (range 6+ -30+). Toxicity in DL0 was observed febrile neutropenia in 1 pt only. Conclusions: The CCRT with CPT and P in DL0 is feasible and shows promising activity in pts with primary LACC.

No significant financial relationships to disclose.

Endometriosis: the pathophysiology as an estrogen-dependent disease

Endometriosis, defined as the presence of endometrial glands and stroma outside of the uterine cavity, develops mostly in women of reproductive age and regresses after menopause or ovariectomy, suggesting that the growth is estrogen-dependent. Indeed, the lesions contain estrogen receptors (ER) as well as aromatase, an enzyme that catalyses the conversion of androgens to estrogens, suggesting that local estrogen production may stimulate the growth of lesions. The expression patterns of ER and progesterone receptors in endometriotic lesions are different from those in the eutopic endometrium. Moreover, estrogen metabolism, including the expression pattern of aromatase and the regulation of 17 beta-hydroxysteroid dehydrogenase type 2 (an enzyme responsible for the inactivation of estradiol to estrone), is altered in the eutopic endometrium of women with endometriosis, adenomyosis, and/or leiomyomas compared to that in the eutopic endometrium of women without disease. Immunostaining for P450arom in endometrial biopsy specimens diagnosed these diseases with sensitivity and specificity of 91 and 100%, respectively. This is applicable to the clinical diagnosis of endometriosis. The polymorphisms in the ER-alpha gene, the CYP19 gene encoding aromatase, and several other genes are associated with the risk of endometriosis. Studies of these will lead to better understandings of the etiology and pathophysiology of endometriosis.

Immunohistochemical localization of aromatase and apoptosis-associated proteins in ovarian serous cystadenocarcinoma arising from ovarian endometriosis

An immunohistochemical study was made of a case of serous cystadenocarcinoma that had been shown to have arisen from ovarian endometriosis. Aromatase cytochrome P450 (P450arom), an enzyme responsible for estrogen biosynthesis, was localized in the epithelial linings of the endometriosis and faintly in the transitional part, whereas it was not expressed in the carcinoma tissue. In contrast, estrogen receptors, progesterone receptors, and apoptosis-associated proteins, Fas, Fas ligand, and Bax were expressed in both endometriosis and carcinoma tissues of the tumor, whereas Bcl-2 was not expressed in either tissue of the tumor. It was suggested that the undifferentiated shift of the histologic grade might result in the loss of P450arom and that the malignant transformation was not caused by an altered balance of apoptosis-associated proteins. Accumulation of these studies may lead to a better understanding of the nature of malignant transformation of ovarian endometriosis.

Progesterone inhibition of functional leptin receptor mRNA expression in human endometrium

Leptin is secreted by adipocytes and regulates appetite through interaction with hypothalamic leptin receptors (OB-R). Leptin is involved in the stimulation of reproductive functions, and local expression of leptin and OB-R in the ovary, oocyte, embryo, and placenta might play a role in early development. The mRNA and protein of the long form leptin receptor (OB-R(L)) but not of leptin are expressed in the human endometrium and the abundance of OB-R mRNA expression varies during the menstrual cycle with a peak in the early secretory phase. We examined the steroidal regulation of OB-R(L) mRNA expression. Northern blot analyses showed that in organ-cultured proliferative endometrial specimens, oestradiol (10(-9) and 10(-8) mol/l) had no acute effect on the OB-R(L) mRNA expression, whereas oestradiol plus progesterone (10(-8), 10(-7) and 10(-6) mol/l) or medroxyprogesterone acetate (10(-8) and 10(-7) mol/l) suppressed the expression by approximately 50%. This progestin-induced suppression was blocked by a concomitant addition of mifepristone. Additionally, incubation of endometrial specimens in the presence of leptin resulted in the phosphorylation of its intracellular target, STAT3 (signal transducer and activator of transcription 3). These results indicate that, in the human endometrium, progestins act via the progesterone receptors to suppress functional OB-R(L) mRNA expression, and may thereby alter the sensitivity of the endometrium to leptin.

Effects of recombinant human macrophage colony-stimulating factor on atherosclerotic lesions established in the aorta of high cholesterol-fed rabbits

Anti-atherosclerotic effects of human macrophage colony-stimulating factor were investigated using rabbits fed a high cholesterol diet. Rabbits fed a diet containing 2% cholesterol for 59 days developed hyperlipidemia and atheromatous aortic plaques. They were then administered 80 microg/kg/day of either macrophage colony-stimulating factor or human serum albumin, as a control, for the next 12 weeks. Compared with the control group, rabbits treated with macrophage colony-stimulating factor had significantly fewer plaques on the inner surface of the thoracic and abdominal aortae, and half the sectional area of thickened intima in the aortic arch, as well as in the thoracic and abdominal aortae. Macrophage colony-stimulating factor also decreased the cholesterol content of the atherosclerotic lesions. Serobiochemical analyses revealed that macrophage colony-stimulating factor increased the levels of high density lipoprotein-cholesterol significantly, without influencing other lipid parameters such as the level of low density lipoproteins. The effects of macrophage colony-stimulating factor were evident until the fourth week of drug injection, at which time anti-human macrophage colony-stimulating factor antibodies were clearly induced in the serum. These results indicate that exogenously administered macrophage colony-stimulating factor suppresses atherosclerotic lesions induced by a high cholesterol diet by activating lipid metabolism in vivo.

Oestrogen receptor-alpha gene polymorphism is associated with endometriosis, adenomyosis and leiomyomata

Endometriosis, adenomyosis and leiomyomata develop in women of reproductive age and regress after menopause or ovariectomy, suggesting that they grow in an oestrogen-dependent fashion. We investigated whether polymorphism in the oestrogen receptor-alpha (ERalpha) gene is related to oestrogen-dependent benign uterine disease. A total of 203 women with regular menstrual cycles underwent laparotomy or laparoscopy and were diagnosed histologically with endometriosis, adenomyosis and/or leiomyomata. Patients with cervical carcinoma in situ, tubal occlusion or adhesion but no other gynaecological disease were considered to be disease-free. A total of 179 women undergoing annual health examination were grouped as reference population. The distribution of PVUII genotypes (PP, Pp, and pp) of the ERalpha gene was different between each pair of the four groups of endometriosis, adenomyosis/leiomyomata, disease-free, and reference population (P = 0.022-0.0005), except between the former two groups. The PP genotype was less frequent in the groups of endometriosis (P = 0.0002) and adenomyosis/leiomyomata (P = 0.002) as compared to that in the disease-free group. In the endometriosis group, there was no difference in the distribution of PVUII genotypes due to complicating diseases (adenomyosis and/or leiomyomata) or severity of the clinical stages. These results suggest that the PVUII polymorphism of the ERalpha gene is associated with the risk for endometriosis, adenomyosis, and leiomyomata.

Progesterone induction of 17beta-hydroxysteroid dehydrogenase type 2 during the secretory phase occurs in the endometrium of estrogen-dependent benign diseases but not in normal endometrium

In the human endometrium, inactivation of 17beta-estradiol to estrone is catalyzed by 17beta-hydroxysteroid dehydrogenase type 2 (17betaHSD2). Previous studies have shown that the 17betaHSD2 activity in the endometrium is elevated during the secretory phase, as compared with the level during the proliferative phase, and that the elevation is in response to progesterone via the progesterone receptors. Recently, it has been demonstrated that aromatase cytochrome P450, the enzyme responsible for estrogen biosynthesis, is not present in the endometrium obtained from normal menstruating women with cervical cancer in situ showing no other gynecological disease (defined as "disease free"), but present in the endometrium obtained from patients with endometriosis, adenomyosis, and/or leiomyomas (defined as "diseased"). However, the previous 17betaHSD studies have been performed without distinguishing between disease-free and diseased endometria. We, therefore, analyzed 17betaHSD2 distinguishing between disease-free and diseased endometria. During the proliferative phase, the abundance of messenger RNA (mRNA) and activity of 17betaHSD2 were comparable in both disease-free and diseased endometrium. However, during the secretory phase, while the abundance of mRNA and activity of 17betaHSD2 increased 4- to 6-fold in diseased endometrium, the 17betaHSD2 remained unchanged in the disease-free endometrium. Kinetic studies showed that the Km was identical among the four groups of endometria, suggesting that the elevation of 17betaHSD2 simply resulted from increased mRNA transcription. Organ culture of proliferative endometria in the presence of progestins resulted in the stimulation of 17betaHSD2 in diseased endometria via the progesterone receptors, whereas disease-free endometrium was not stimulated by progestins. These results suggest that the previous paradigm that 17betaHSD2 activity in the endometrium is elevated during the secretory phase is confined to diseased endometrium but not to disease-free endometrium and that the estrogen metabolism is altered in the endometria of the patients with estrogen-dependent benign diseases.

Expression of aromatase cytochrome P450 in eutopic endometrium and its application as a diagnostic test for endometriosis

Endometriotic implants, like other estrogen-dependent tumors, contain both estrogen receptors and aromatase cytochrome P450 (P450arom), suggesting that at a local level, endometriotic implants produce estrogens, which may be involved in tissue growth through interaction with the estrogen receptors. P450arom is also expressed in the eutopic endometria of patients with endometriosis, adenomyosis, and/or leiomyomas, whereas neither P450arom protein nor mRNA is expressed in the eutopic endometria of normal menstruating women with cervical carcinoma in situ yet showing no other gynecological disease (disease-free). Examination of P450arom expression in endometrial biopsy specimens enables the physician to discriminate between the presence and absence of endometriosis, and may be used as an initial screening at outpatient infertility clinics. Copyrightz1999S.KargerAG,Basel

Expression of leptin receptor in human endometrium and fluctuation during the menstrual cycle

Leptin is secreted by adipocytes and regulates appetite through interaction with hypothalamic leptin receptors (OB-R). Accumulated evidence shows that leptin is involved in the stimulation of reproductive functions and that local expression of leptin and OB-R in the ovary, oocyte, embryo, and placenta plays a role in early development. To investigate the role of leptin in implantation, we examined the expression of OB-R and leptin in the human endometrium. Northern and Western blot analyses and RT-PCR showed that the long form of OB-R (OB-R(L)) messenger ribonucleic acid (mRNA) and protein were expressed. In contrast, leptin mRNA or protein was not detected. All of the splice variants of OB-R (OB-R(T)) and OB-R(L) transcripts were expressed in 90% and 84% of the cases, respectively. OB-R mRNA expression peaked in the early secretory phase. Decidual tissue of early gestation also expressed OB-R(T) and OB-R(L). Their incidence and abundance were comparable among endometria with benign uterine diseases and disease-free endometria and were not related to a body mass index within the normal range. The present results indicate that OB-R, but not leptin, is expressed in the human endometrium.

Heparin cofactor II inhibits thrombus formation in a rat thrombosis model

Heparin cofactor II is postulated to be an extravascular thrombin inhibitor that is physiologically stimulated by dermatan sulfate. However, the role of heparin cofactor II has not yet been clearly demonstrated in vivo. In this study, we estimated the antithrombotic effect of heparin cofactor II administered exogenously in a rat model of thrombosis. Thrombus was induced in the rat femoral artery by endothelial damage due to the photochemical reaction between systemically injected rose bengal and transillumination with green light. Pretreatment with heparin cofactor II significantly prolonged the time required to occlude the femoral artery (occlusion time) in a dose-dependent manner. At an effective dose in this thrombosis model, heparin cofactor II did not prolong the activated partial thromboplastin time and the prothrombin time in normal rats. Argatroban, a selective synthetic thrombin inhibitor, significantly prolonged the occlusion time. However, argatroban also prolonged the activated partial thromboplastin time and prothrombin time at an effective dose. These results suggest that the administration of heparin cofactor II in vivo effectively inhibited thrombus formation on the vessel walls whose endothelium is damaged without a prolongation of the coagulation time while heparin cofactor II may also inhibit the thrombin activity in the subendothelial tissue in vivo.

Detection of aromatase cytochrome P-450 in endometrial biopsy specimens as a diagnostic test for endometriosis

OBJECTIVE

To evaluate the clinical usefulness of examining endometrial biopsy specimens for aromatase cytochrome P-450 as a diagnostic test for endometriosis.

DESIGN

Retrospective, case-controlled study.

SETTING

Department of Obstetrics and Gynecology, Kyoto Prefectural University of Medicine, Kyoto, Japan.

PATIENT(S)

One hundred five women of reproductive age with normal menstrual cycles underwent endometrial biopsy laparotomy or laparoscopy, and examination of their tissue revealed endometriosis, adenomyosis, and/or leiomyomas. Patients who had cervical carcinoma in situ but no other gynecologic disease were considered to be disease-free.

INTERVENTION(S)

Endometrial biopsy specimens were collected.

MAIN OUTCOME MEASURE(S)

The expression of aromatase cytochrome P-450 was examined by reverse transcription-polymerase chain reaction and immunohistochemical analysis. The distribution and intensity of the immunostaining was assessed using a semiquantitative index designed H-score.

RESULT(S)

Immunostaining for aromatase cytochrome P-450 was detected in biopsy specimens obtained from patients with endometriosis, adenomyosis, and/or leiomyomas but not in specimens obtained from disease-free patients (H-score <20), with a sensitivity and specificity of 91% and 100%, respectively.

CONCLUSION(S)

The expression of aromatase cytochrome P-450 in biopsy specimens of eutopic endometrium distinguishes between disease-free women and women with endometriosis, adenomyosis, and/or leiomyomas. This technique can be used at outpatient infertility clinics as an initial screening procedure to rule out the presence of estrogen-dependent disease.

Leptin directly stimulates aromatase activity in human luteinized granulosa cells

Leptin, the obese (ob) gene product, is secreted by adipocytes and regulates appetite through interaction with hypothalamic leptin receptors. Leptin may also have a stimulatory effect on reproductive function. Furthermore, leptin receptor mRNA is expressed in the ovary, suggesting a direct effect on its function. The present study examines the direct role of leptin on the oestrogen-producing activity in human luteinized granulosa cells. The cells were obtained from in-vitro fertilization pre-ovulatory follicles, precultured for 24 h in the presence of 5% charcoal-treated serum, and incubated for 48-96 h in a serum-free medium containing recombinant human leptin, follicle stimulating hormone (FSH), and/or insulin-like growth factor-I (IGF-I). A single addition of leptin (0. 5-10 ng/ml) stimulated aromatase activity with the incubation time of up to 96 h. The addition of leptin (1 ng/ml) further augmented the stimulation by a single addition of FSH (100 ng/ml) or IGF-I (100 ng/ml), or a combination of both. A single addition of leptin (1 ng/ml) or a combination of leptin (1 ng/ml), FSH (100 ng/ml), and IGF-I (100 ng/ml) gave rise to an increase in each parameter of oestrogen-producing activity measured, i.e. P450arom mRNA level, P450arom protein level, aromatase specific activity, and the oestradiol concentration in the culture supernatant. However, the production of progesterone did not change. These results indicate that leptin stimulates oestrogen production by increasing P450arom mRNA and P450arom protein expression and, consequently, aromatase activity by its direct action on the human luteinized granulosa cells.

Retropharyngeal abscess after radiation therapy and cis-platinum, 5-fluorouracil treatment for nasopharyngeal carcinoma with collagen disease: report of two patients and a review of the literature

Collagen disease are frequently associated with malignant tumors. Recently, radiotherapy combined with chemotherapy has been recommended for improving the efficacy of treatment for nasopharyngeal carcinoma. Two patients with nasopharyngeal carcinoma complicated by collagen diseases (dermatomyositis in one, and Sjögren's syndrome with mixed connective tissue disease in the other) were given radiotherapy combined with chemotherapy consisting of cis-platinum and 5-fluorouracil. Following this combination therapy, both patients developed retropharyngeal abscess and ulceration of the mucosal membrane on the posterior wall of the oropharynx; there was no tumor cell involvement. Because these injuries were more severe than would have been expected from radiotherapy alone, it is recommended that special attention be paid to combination therapy in patients with nasopharyngeal carcinoma complicated by collagen disease.

[Growth and serial changes of bone calcium content after renal transplantation in childhood]

We evaluated metacarpal index (MCI) and bone mineral content (BMC) of right 2nd metacarpal bone X-ray films using the microdensitometer technique in 12 pediatric and 32 adult renal transplant (Tx) recipients. Grafts were well functioning for more than 1 year in all adults (serum creatinine < or = 2.0 mg/dl) and in 9 of the children (serum creatinine < or = 1.2 mg/dl). Immunosuppression consisted of cyclosporin (CyA), methylprednisolone (MPL), mizoribine and anti-lymphocyte globulin for all children. 18 of the adults were given CyA and 14 were given conventional immunosuppression. BMC was found to be increased in both children with good renal function and in adults. MCI was improved in 2 children with good renal function and in 2 adults using CyA. Immunosuppression of CyA and low dose MPL had an improving effect on renal osteodystrophy. Alternate-day MPL dosage was between 1, 6 and 7.3 mg/m2/day (mean 3, 6 mg/m2/day) in the 9 children with good renal function. Bone age of the children was seen to be developed in accordance with calendar age. Growth velocity of the 9 children with good renal function was better than the mean level of normal children. However, growth velocity at 3 years after Tx declined slightly, compared with that within 2 years. Similarly, somatomedin C was above the normal range within 2 years after Tx. Thus, bone metabolism after Tx may have been influenced by serial changes of somatomedin C.

Usefulness of a novel monoclonal antibody against human osteocalcin in immunohistochemical diagnosis

A novel monoclonal antibody against human osteocalcin, recently established in our laboratory, was shown by immunoblotting and immunohistochemistry to react specifically with human osteoblasts. In the present study, the antibody was applied to the immunohistochemical diagnosis of human bone tumours, especially osteoblastic tumours. The antibody reacted with all 27 osteosarcomas. No positive reaction was found either in chondrosarcoma, giant cell tumours of bone, soft tissue tumours or epithelial tumours. A positive reaction was found preferentially in the cytoplasm of most of the osteosarcoma cells, but not in the extracellular matrix. Since the antibody reacted with formalin-fixed and paraffin-embedded tissues, it will be a useful tool for routine immunohistochemical diagnosis of osteoblastic lesions.

Production of monoclonal antibodies specific for human bone gamma-carboxyglutamic acid containing protein

Murine monoclonal antibodies specific for human bone gamma-carboxyglutamic acid containing protein (BGP) were produced against BGP purified from young adult human long bones. The amino acid composition of purified protein corresponds with that of human BGP, and Western blot analysis revealed that the antibodies reacted most intensely with the cytoplasm of osteoblasts and less intensely with the cytoplasm of osteocytes, but did not react with any other cells, such as chondrocytes, or osteoclasts. Because of their ability to react with routinely processed tissue sections and their marked reactivity with human osteoblastic cells, the antibodies are expected to be a useful tool for studying the process of ossification in human bones and for the immunohistochemical diagnosis of human osteogenic tumours.

Effect of radiation on the expression of carcinoembryonic antigen of human gastric adenocarcinoma cells

The changes of antigenic expression of cultured human gastric adenocarcinoma MKN45 cells caused by irradiation were investigated to elucidate the immune responses to localized irradiation. The expression of carcinoembryonic antigen (CEA) showed remarkable increases in the culture supernatant and on the surface of the membrane of irradiated cells. The expression of major histocompatibility complex Class I antigen on the membrane also was enhanced by irradiation. In addition, the irradiated cell groups, when analyzed using a CEA-specific probe, showed remarkable increases in the CEA mRNA. These enhancements increased in the 10-Gy and 15-Gy irradiated populations compared with the 5-Gy irradiated population. These results suggest that the enhancement of expression of CEA by radiation takes place at the CEA gene expression (mRNA) level but not at the protein level.

Radioimmunoscintigraphy of human pancreatic carcinoma xenografts in nude mice with 131I-labeled monoclonal antibody

Encouraged by reports of radioimmunoimaging of colorectal carcinomas and by examining an immunohistochemical report on resected pancreas cancer tissues, we studied the diagnostic potential of radioimmunoimaging with the radioiodinelabeled monoclonal antibody to the surface antigen of a pancreas cancer cell line. A monoclonal antibody (MoAb; HC-1) to a human pancreas cancer cell line (HGC25)5 was labeled with radioiodine and injected into athymic nude mice implanted with human pancreas cancer cells. Antibody HC-1 was cleared from the circulation and accumulated significantly in the implanted tumor sites.

[Preparation of monoclonal antibodies against human bone gamma-carboxyglutamic acid containing protein (BGP) and its immunohistochemical application to various human tissues]

Bone gamma-carboxyglutamic acid containing protein (BGP) has been considered to play an important role in mineralization of bone, because this protein is capable of binding to calcium ions. However, the function and localization of BGP in normal bones have not yet been fully understood. In this study, we prepared monoclonal antibodies against human BGP, by immunizing BALB/c mice with human BGP. All five monoclonal antibodies obtained were shown to bind specifically to human BGP, but not to the other bone-derived proteins. In immunohistochemical analysis, these antibodies were shown to react with osteoblasts and osteocytes in normal human bone tissues, but not with chondrocytes, osteoclasts and osteoid tissues. These antibodies are expected to be useful for the diagnosis of human osteoblastic tumors and also for the analysis of the role of BGP in the ossification process in bone.

Identification of transformation-related antigen by monoclonal antibody on Swiss 3T3 cells induced by transfection with murine cultured colon 36 tumor DNA

The cell surface antigen associated with the transformed state of cells that could grow in an anchorage-independent manner was analyzed by use of techniques of DNA transfection and hybridomas secreting the monoclonal antibody (MoAb). Spleen cells of C57BL/6 mice immunized with a highly tumorigenic, chemically induced murine cultured colon 36 tumor (C-C36) of BALB/c origin were hybridized with NS-1, a hypoxanthine phosphoribosyltransferase-deficient myeloma line of BALB/c mice. Screening of hybridomas revealed an antibody that reacted with C-C36 and transformed Swiss 3T3 cells growing in soft agar after transfection of 3T3 cells with C-C36 DNA. The hybridomas that did not react with nontransformed 3T3 and the less tumorigenic BALB/c hemangioendothelioma line D10 were then selected. An MoAb was designated "#71295." This MoAb immunoprecipitated the antigen that consisted of 65,000- and 14,000-molecular-weight components with soluble C-C36 membrane antigens. It also reacted with 2 other chemically induced syngeneic colon tumor lines, cultured colon 26 tumor line and cultured colon 51 tumor line, and with fibrosarcoma Meth A. However, #71295 was not found in NS-1, D14, and BALB/c normal thymus, liver, colon, and kidney tissues. In addition, this MoAb could not inhibit the anchorage-independent growth of C-C36 and transformed 3T3 cells. These results suggest that although the molecule defined by #71295 might not be associated with the anchorage independence of cell growth, it could be a newly expressed determinant on the cell surface that is related to the events of cell transformation.

Specific cytotoxicity of a long-term cultured T-cell clone on human autologous mammary cancer cells

We established an autologous specific T-cell killer clone, TcHMC-1, that has been cultured and has retained its function for over 1 year. TcHMC-1 and target cells (HMC-1-8) were derived from the metastatic pleural effusion of a patient with mammary carcinoma. At culture initiation, pleural exudative lymphocytes (PLEL) already demonstrated a high cytotoxic activity against uncloned HMC-1 breast tumor cell targets but not against autologous fibroblasts and K562 targets, and phenotypically these cells showed 100 and 90% reactivity with OKT3 and OKT8 monoclonal antibodies, respectively. However, at the early phase of cultivation under interleukin 2, PLEL had a relatively high cytotoxicity against some allogeneic tumor cells. Furthermore, the longer these PLEL were cultured with interleukin 2 and stimulated with MMC-treated HMC-1, the less cytotoxic activity of PLEL against HMC-1 targets became. We then cloned PLEL as well as HMC-1 tumor cells, and an autologous pair of TcHMC-1 and a target cell clone, HMC-1-8, was successfully obtained. TcHMC-1 showed more than 60% specific cytotoxicity against HMC-1-8, and it was confirmed, using cold target inhibition assays, that TcHMC-1 did not demonstrate nonspecific cytotoxicity against allogeneic targets as well as the natural killer cell activity. Moreover, we examined the in vivo action of TcHMC-1 against HMC-1-8 cells by the Winn assay using nude mice. The data showed that s.c. injections with a mixture of TcHMC-1 and HMC-1-8 clearly resulted in a failure of tumor development in the nude mice even 12 weeks after injections, whereas mice given injections of HMC-1-8 and allogeneic T-lymphocytes cultured with interleukin 2 developed tumors. The autologous pair of a killer T-cell clone and tumor line could be very useful for future investigations of the specific destruction of autologous tumor cells by cytotoxic T-lymphocytes, including analysis for tumor-specific antigens possibly of rejection type and clonotypic T-cell antigen receptors.

Partial purification of C-C36 tumor rejection antigen molecules commonly expressed on syngeneic murine colon tumors, C-C36 and C-C26

The tumor-specific transplantation antigens (TSTAs) of BALB/c mouse colon tumor C-C36 were characterized by gel filtration (TKS-gel FPLC), ion exchange chromatography (Mono Q FPLC) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. The cell surface antigens were solubilized noncytolytically with 2.5% n-butanol. It was demonstrated that the C-C36 antigens responsible for tumor rejection activity against C-C36 cells had a molecular weight of less than 200,000, and were eluted at 0.4-0.5M NaCl. On the other hand, the cross TSTAs expressed on C-C26 cells were eluted 0.2M NaCl. SDS-PAGE analysis of the partially purified antigens showed that the C-C36 TSTAs had four bands corresponding to molecular weights of 75,000, 68,000, 60,000 and 40,000. In contrast, the cross TSTAs expressed on C-C26 cells gave several major bands corresponding to 110,000, 94,000, 60,000 and 38,000, in addition to faint bands of 75,000 and 68,000. These results indicate that, although the partially purified C-C36 and C-C26 colon tumor antigens inducing rejection of C-C36 tumor challenge in syngeneic hosts showed differences in the ionic strength at which they were eluted, there are three common molecules with molecular weights of 75,000, 68,000 and 60,000, suggesting that these common molecules might be the tumor antigens responsible for the C-C36 colon tumor rejection.

Phenotyping of malignant hematopoietic cells. Analysis of 1200 cases of leukemia-lymphoma

1255 cases of leukemia-lymphoma were tested between 1972 and 1984 by multiple marker analysis. Routine leukemia phenotyping was performed using standard morphological and cytochemical techniques in combination with clinical and histo-pathological information; the main emphasis was put on immunological surface marker analysis using erythrocyte rosette assays, TdT and a large panel of poly- and monoclonal antibody tests. The 1255 cases were divided into these major types and subtypes: 349 cases of ALL and related immature T- and Burkitt-lymphomas (cALL, pre B-ALL, B-ALL and Burkitt-lymphomas, T-ALL and immature, mostly leukemic T-lymphomas, Null-ALL), 454 cases of mature T- and B-cell malignancies (T-CLL, mycosis fungoides, Sezary-syndrome, T-lymphomas, B-CLL, hairy cell leukemia, multiple myeloma, B-lymphomas), 263 cases of acute myeloid leukemias (AML, AMMoL/AMoL), 182 cases of chronic myeloid leukemias (CML in chronic phase, CMoL, CML in blast crisis), 6 cases of erythroleukemia and 1 case of megakaryoblastic leukemia. A simplified classification scheme which has been used in our laboratories is presented. Phenotyping is of diagnostic, prognostic and therapeutic relevance, most evidently for patients with ALL. Routine leukemia phenotyping should be performed with highly standardized techniques and reagents and by combining information from several fields in the multiple marker analysis. New areas of leukemia research might become very useful for the routine procedure of phenotyping.

The effects of K+-depolarization medium, chelating agents and thiol groups on cadmium uptake and efflux in the guinea-pig taenia coli

Cadmium uptake by taenia coli was dose-dependent, achieving equilibrium after approximately 60 min of incubation. The SH-blocker, N-ethylmaleimide inhibited cadmium uptake. When muscles were washed with normal medium or that containing 0.5 mM EDTA following 0.5 mM Cd2+ treatment for 60 min, the tissue cadmium concentration reached equilibrium levels after 60 min and approximately 43 or 27% of the initial tissue cadmium concentration was retained, respectively. Both glutathione and dithiothreitol also increased cadmium efflux. However the contractions of glycerinated taenia coli caused by Ca2+ and Mg-ATP, completely returned to control values after washing with 0.5 mM EDTA medium following 0.5 mM Cd2+ treatment for 60 min, suggesting that EDTA seems to exert intracellular effects in glycerinated taenia coli. These results suggest that SH-dependent mechanisms in cadmium uptake play a role in intact taenia coli. In addition, in intact taenia coli, Cd2+ are accumulated in intracellular compartments which EDTA cannot reach and may exert an inhibitory action on internal sites in the cells.

Temperature dependency of cadmium uptake and relaxant effect of cadmium in guinea-pig taenia coli

Cadmium fluxes were studied under low temperature in order to assess the site of action of Cd2+ in taenia coli. Following a treatment with 0.5 mM Cd2+ for 30 min at 37 degrees C, the responses to high-K+ were not reversed after washing with medium containing 0.5 mM disodium edetate (EDTA). However, at 30 min preincubation with 0.5 mM Cd2+ at 4 degrees C, the responses markedly returned by the washing. The cadmium uptake was much slower at 4 degrees C. The cadmium in muscle preincubated at 4 degrees C was markedly eliminated by EDTA. Thus, the increase in the size of the fraction of total cadmium not eliminated by EDTA was temperature dependent. These data suggest the possibility that the total cadmium not eliminated by EDTA in taenia coli may be accumulated in the intracellular compartment where EDTA cannot reach.

Time course of the spasmolytic effect of cadmium and cadmium uptake in guinea-pig taenia coli

The relationship between tension inhibitory action of cadmium and cadmium uptake was investigated in the smooth muscle of taenia coli. Following a treatment with 0.5 mM Cd2+ for short periods (1, 5 min), the tension to high-K+ returned to a greater extent after washing with disodium edetate (EDTA) or cysteine, compared to normal medium. However, the restored tension to the high-K+ decreased with increasing duration of Cd2+ treatment. With a longer duration of 0.5 mM Cd2+ treatment, the cadmium uptake increased and the size of cadmium fraction bound to cells firmly increased. It is suggested that Cd2+ binds initially to the surface membrane of taenia coli and that Cd2+ subsequently migrates to a compartment that EDTA cannot reach.

[Relationship between T cell infiltration in breast cancer tissues and prognosis]

The relationship between the degree of T cell infiltration in cancer tissues and prognosis was studied in 26 patients with breast cancer. The degree of T cell infiltration was divided into 4 groups according to the number of infiltrating T cells. There was a good correlation between the degree of T cell infiltration and the survival period or disease-free period. It may be clinically useful to check the degree of T cell infiltration in cancer tissues for predicting the prognosis of patients with breast cancer.

Effects of basement membrane matrix on the culture of fetal mouse hepatocytes

The effects of laminin, fibronectin and type IV collagen, all of which are major matrix components of the basement membrane, upon fetal mouse hepatocyte culture were studied. Among these matrices, laminin showed the greatest effect on DNA synthesis, cell proliferation, the secretion of alpha-fetoprotein and cell attachment. The effects of fibronectin and type IV collagen were slight with regard to the promotion of growth and cell attachment. However, there were no differences in the secretion of albumin into the media among the groups. These results suggest that laminin may be necessary for the cellular growth and functional maintenance of immature liver cells during normal development of the liver in vivo.

B-cell malignancies and differentiation antigens defined with monoclonal antibodies

Monoclonal antibodies directed to B-cell lineage were produced. They were characterized by their reactivity with a variety of human hematopoietic cell lines and normal lymphoid cells and by the immunohistological distribution of cells positive for the antibodies. Some of them were specific for B-cell lineage at various stages of B-cell differentiation and some were, in addition, cross-reactive with other cell lineages. These newly produced antibodies were utilized to dissect and characterize B-cell malignancies and were applied for classification of B-cell malignancies.

Mechanism of inhibition of contraction by cadmium in guinea-pig taenia coli

Further evidence about the mechanism of the inhibition of contractions caused by cadmium ions (Cd2+) in guinea-pig taenia coli has been sought. Cd2+ at a concentration of 0.5 mM completely inhibited the high-K (40 mM)-induced contraction within 3-5 min. Cd2+ did not shift the Ca2+-induced concentration-response curve to the right in Ca2+-free K+ depolarized muscle, although it reduced the Ca2+ response size. The K+-induced increase in tissue calcium content and 45Ca uptake determined by the lanthanum method was significantly reduced in the presence of Cd2+ (0.5 mM) and the contractions of the glycerolated taenia coli were inhibited with increasing Cd2+ (0.001-0.5 mM). Muscle strips, incubated in a medium containing 0.5 mM Cd2+, accumulated greater amounts of cadmium than within the extracellular space. It is suggested that the inhibitory action on tension produced by Cd2+ in taenia coli may result from the interference of calcium permeability at the cell membrane. There is the possibility that Cd2+ acts on the contractile system of the muscle.

A monoclonal antibody defining human B cell differentiation antigen (HLB-1 antigen)

A new monoclonal antibody specific for human B cell differentiation antigen (HLB-1) is produced by a hybridoma established by fusion of splenocytes of mice immunized with the Epstein-Barr virus (EBV)-transformed peripheral B cell line, RPMI-8057. This monoclonal, antibody designated anti-HLB-1 monoclonal antibody (anti-HLB-1), reacted with surface immunoglobulin (sIg)-positive B cells of normal peripheral blood and lymphoid tissues and sIg-positive leukemic cells. The cells of T cell leukemia, non-T non-B acute lymphoblastic leukemia (ALL) and nonlymphoid leukemia were HLB-1 negative. These data were further confirmed by studying a panel of cultured human hematopoietic cell lines. Anti-HLB-1 reacted with B cell lines derived from pre-B, Burkitt's lymphoma, B cell type ALL and EBV-transformed peripheral B cells. Anti-HLB-1 was reactive with only one of three human myeloma cell lines, and with none of the T cell, myeloid and non-T non-B ALL cell lines. This newly defined HLB-1 antigen is different from other conventional human B cell markers such as sIg, Ia antigens, and receptors for the Fc portion of Ig and complement C3.

[Antibodies against human lymphocytes]

The introduction of hybridoma technology has greatly contributed to the identification and the characterization of a variety of cell surface antigens present on human lymphoid cells. Rapid progress has recently been made in generating monoclonal antibodies against human lymphoid cells and extensive studies in clinical medicine have defined the potential application of these monoclonal antibodies. In this review, we summarize the main similarities and differences among these monoclonal antibodies.

Surface antigenic phenotypes of human T-cell leukemia corresponding to those of post-thymic T cells

Leukemic cells from eight adult patients with various types of T-cell leukemias, including one patient with lymphosarcoma cell leukemia (T-LSL), two patients with chronic lymphocytic leukemia (T-CLL), and five patients with adult T-cell leukemia (ATL), were analyzed for their surface antigenic phenotypes with a series of monoclonal antibodies directing to human T-cell differentiation antigens. All of the leukemic T cells studied were regarded as being of post-thymic T-cell origin because of their ability to form rosettes with sheep red cells under the condition at 4 degrees C but not 37 degrees C as well as the expression of human Ly-1-like but not TL-like antigen on their cell surfaces. By using monoclonal antibodies to a variety of human of three distinct categories. Thus, one patient with T-LSL had cells with Leu-1+2a+3a+ phenotype, which might reflect possible post-thymic precursor T cells, whereas one patient with T-CLL had cells with the same phenotype (Leu-1+2a+3a-) as normal cytotoxic/suppressor T cells. The latter cells also expressed Ia antigens as defined by monoclonal antihuman Ia antibody. The remaining six cases, including one T-CLL and five ATL patients had leukemic cells with the same phenotype (Leu-1+2a-3a+) as normally found on helper/inducer T cells, despite distinct clinical and immunological features between T-CLL and ATL. Some clinical findings observed in those patients may reflect functional activities retained by their leukemic T cells.

Immunochemical characterization of human TL-like (T48) and Ly 1-like (T72) glycoproteins using two-dimensional polyacrylamide gel electrophoresis

Xenoantisera, designated AT48 and AT72, were developed by immunizing rabbits with human thymus cell membrane and guinea-pigs with a T-cell glycoprotein purified from leukaemic T-cell membrane. Whereas AT48, after appropriate absorption, reacted exclusively with the majority of thymocytes (mainly cortical thymocytes) among normal lymphoid populations, AT72 reacted with virtually all of the thymus and T cells but not with B cells. Thymocytes, which were strongly reactive with AT72, existed in the thymic medulla, but cortical cells were also very weakly reactive with AT72. When cultured T-cell lines, all of which were derived from patients with T-cell-type acute lymphatic leukaemias, were tested for their reactivities with AT48 and AT72 by immunofluorescence, we found that AT48 stained certain T-cell lines, whereas AT72 stained all of the T-cell lines tested so far. Immunochemical data showed that AT48 precipitated a 48K molecular weight (mol. wt) glycoprotein from 125I-labelled thymus cell surface glycoproteins, which appeared to be very weakly associated with a 12K mol. wt component. These 48K and 12K mol. wt components precipitated by AT48 showed almost identical isoelectric points (pI) to those of HLA heavy chain and beta 2-microglobulin respectively. AT72, on the other hand, precipitated a 72K mol. wt glycoprotein from thymus and T cells as well as from leukaemic T cells. A less prominent 65K mol. wt glycoprotein was also precipitated by AT72 from thymus and T cells but not from leukaemic T cells. These two components showed almost identical pI ranging approximately from 4 to 7, and this marked charge heterogeneity observed was reduced by neuraminidase treatment, suggesting that it reflects the heterogeneity in sialylation of this molecular species. We concluded from these data that AT48 and AT72 used in this work could detect human homologues of mouse TL and Ly 1 antigens respectively.

Immunohistological detection of B lymphocytes in the rat lymphoid organs by using anti-rat B lymphocyte serum

Anti-rat B lymphocyte serum (ARBS) was prepared by immunizing rabbits with purified B cells from rat spleen and by absorbing the rabbit serum with rat red blood cells and syngeneic sarcoma cells. The specificity of ARBS for rat B cells was confirmed by various cytologic and immunofluorescence studies. By indirect immunofluorescence on tissue sections of rat spleen and lymph nodes, anatomical localizations of B cells in lymphoid organs were lymphoid follicles of the lymph node and lymphocyte corona surrounding periarteriolar lymphoid sheaths of the spleen; while cells located in the thymus-dependent area were essentially devoid of immunofluorescence or no cytoplasmic immunofluorescence was observed in plasma cells. Thus, the B cell distribution in tissue sections was clearly demonstrated with ARBS. When the cross-reactivity of ARBS with mouse B cells was studied by complement-dependent cytotoxicity and immunofluorescence, it was found that mouse B cells shared at least one determinant of rat B lymphocyte specific antigens (RBLA) with rat B cells, and that the distribution pattern of the cross-reacting antigens in mouse lymphoid tissues was essentially the same as that of RBLA in rat lymphoid organs.

Marker profiles of human leukemia and lymphoma cell lines

By means of the multiple marker analysis, a total of 55 human leukemia-lymphoma cell lines which included 15 T-cell, 30 B-cell, four myelomonocytic-cell, and six non-T, non-B cell lines was characterized for their marker profiles. The multiple markers used included a number of cell surface markers as detected by either rosette or immunofluorescence tests, enzyme assays, cytogenetic analysis, and certain functional assay. Based on the criteria previously defined it was found that all the cell lines were proved to represent original leukemia-lymphoma of ALL, AML, CLL, CML in blastic phase or variety of lymphomas. The monoclonality, a "frozen" state at a specific state of differentiation-maturation, and cytogenetic marker in each leukemia-lymphoma cell line were remarkable common properties and were stable for years of cultivation. Similar, if not identical, general characteristics were observed in the study on 344 cases of uncultured fresh leukemia-lymphomas by the multiple marker analysis. While no single marker specific to any type of tumor was found, the study offers not only a basis for better understanding of the biology of leukemia-lymphoma but also an insight into normal hematopoietic cell differentiation in man.

Isolation and partial characterization of a 72,000-dalton glycoprotein (Tgp72) on human thymus and T cells: possible relationship to mouse Ly-1 antigens

A xenoantiserum was raised in guinea pigs to a human T cell antigen (Tgp72) partially purified from cell membrane of T cell leukemia cells from a patient with chronic lymphosarcoma cell leukemia of T cell-type by using sequential chromatographic procedures. The antiserum reacted with all of human thymus and peripheral T cells as well as with a variety of cultured leukemic T cell lines, but not with B cells, granulocytes, and other cultured lymphoid cell lines, including normal B cell, Burkitt, myeloid, and non-T non-B cell lines. Immunoprecipitated material from 125I-labeled thymocyte, T cell, and T cell leukemia cell-surface glycoproteins by this antiserum was analyzed by SDS-polyacrylamide gel electrophoresis, which disclosed a single component with a m.w. of 72K (Tgp72). Further immunochemical data suggest that Tgp72 antigen on human thymus and T cells is an acidic glycoprotein composed of a single polypeptide rather than sulfhydryl-linked subunits, showing a marked electric charge heterogeneity in DEAE anion-exchange resin chromatography. This is further confirmed by the data obtained from 2-dimensional polyacrylamide gel electrophoresis, indicating that Tgp72 is a 72K m.w. glycoprotein with an isoelectric point ranging from 4 to 7. Because of its similarity in tissue distribution and immunochemical characteristics, Tgp72 on human thymus and T cells was assumed to be a human homologue of Ly-1 antigens in murine system.

Isolation and partial characterization of a 72,000-dalton glycoprotein (Tgp72) on human thymus and T cells: possible relationship to mouse Ly-1 antigens

A xenoantiserum was raised in guinea pigs to a human T cell antigen (Tgp72) partially purified from cell membrane of T cell leukemia cells from a patient with chronic lymphosarcoma cell leukemia of T cell-type by using sequential chromatographic procedures. The antiserum reacted with all of human thymus and peripheral T cells as well as with a variety of cultured leukemic T cell lines, but not with B cells, granulocytes, and other cultured lymphoid cell lines, including normal B cell, Burkitt, myeloid, and non-T non-B cell lines. Immunoprecipitated material from 125I-labeled thymocyte, T cell, and T cell leukemia cell-surface glycoproteins by this antiserum was analyzed by SDS-polyacrylamide gel electrophoresis, which disclosed a single component with a m.w. of 72K (Tgp72). Further immunochemical data suggest that Tgp72 antigen on human thymus and T cells is an acidic glycoprotein composed of a single polypeptide rather than sulfhydryl-linked subunits, showing a marked electric charge heterogeneity in DEAE anion-exchange resin chromatography. This is further confirmed by the data obtained from 2-dimensional polyacrylamide gel electrophoresis, indicating that Tgp72 is a 72K m.w. glycoprotein with an isoelectric point ranging from 4 to 7. Because of its similarity in tissue distribution and immunochemical characteristics, Tgp72 on human thymus and T cells was assumed to be a human homologue of Ly-1 antigens in murine system.

Human thymus antigen: characterization and its expression on human leukemias

Specific anti-human thymus xenoantiserum (ATS) was utilized for characterizing a human thymus antigen (HTA) preferentially expressed on human thymocytes. Binding of ATS with different cell types was studied by immunofluorescence and immunoperoxidase techniques, as well as by radioimmunoprecipitation (RIP) followed by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). ATS reacted selectively with the majority (87%) of human thymocytes among normal lymphoid cell populations tested. In the thymus, HTA was expressed largely on cortical thymocytes but not on those cells located in the thymic medulla. When 20 cases of different types of lymphatic leukemias were studied with ATS, HTA was found on acute lymphoblastic leukemia cells rosetting with sheep erythrocytes (T-ALL) but not on other lymphatic leukemia cases, including chronic lymphocytic leukemia cells rosetting with sheep red blood cells (T-CLL). SDS-PAGE analysis of immunoprecipitates formed between ATS and radiolabeled cell-surface components of human thymocytes demonstrated that ATS bound a 48,000-molecular-weight component that could be adsorbed to Sepharose 4B coupled with Les culinaris hemagglutinin and could be labeled by periodate-tritiated borohydride, indicating that HTA is a sialoglycoprotein. Similar antigen molecules were also precipitated by ATS from T-ALL cells but not from other lymphatic leukemia cells. Five T-ALL-derived cell lines were tested with ATS by immunofluorescence and by RIP and SDS-PAGE, but only two cell lines (MOLT-3 and P12/Ich) possessed HTA molecules on their cell membrane.