Ultrastructural study of TPA-induced cell motility: human well-differentiated rectal adenocarcinoma cells move as coherent sheets via localized modulation of cell-cell adhesion

We previously found that 12-O-tetradecanoylphorbol-13-acetate (TPA)-enhanced invasion of Matrigel was associated with augmentation of cell motility but not with metalloproteinase activity in a highly metastatic variant (L-10) of human rectal adenocarcinoma cell line RCM-1. In a two-dimensional cell motility assay, TPA induced active L-10 cell locomotion with characteristic morphology; the cells moved outwards from the cell islands mainly as a localized coherent sheet of cells. The leading cells showed locomotor morphologies with fan-shaped leading lamellae while the following cells had cell contacts on all sides and appeared to lack leading lamellae. In the present ultrastructural study, the following cells frequently showed tapering cytoplasmic protrusions and leading lamella-like processes underlapping a preceding cell, indicating that the locomotion mechanism is almost the same for both the leading and following cells. For this type of locomotion as a coherent sheet we propose that localized modulation of cell-cell adhesion was induced such that wide intercellular gaps occurred at the lower portion of the cells to allow the cells to extend the tapering cytoplasmic processes and leading lamellae while close cell-cell contacts remained at the upper portion of the cells. These TPA-induced changes took place predominantly in the cells at the periphery of the cell islands, while the cells in the middle of the cell islands maintained close cell-cell contacts including complex interdigitation all around the cells, suggesting the modulation of TPA action by cell-cell interaction. Additionally, consistent with the evidence for junctional complexes between the cells moving outwards, the Lucifer-yellow dye transfer studies showed some, limited cell-cell coupling, suggesting the presence of at least some gap junctional intercellular communication in the moving cell sheets.

Concomitant expression of hepatocyte growth factor (HGF), HGF activator and c-met genes in human glioma cells in vitro

Three new cell lines of human glioblastoma have been established. These cells co-expressed hepatocyte growth factor (HGF) and its receptor, c-Met, genes in vitro. Reverse-transcriptase/polymerase-chain reaction study revealed that the cells also expressed gene for HGF activator, a recently cloned serine proteinase, suggesting that HGF might have a role in glioma cells in vitro as an autocrine factor. The activator mRNA was also detected in other well-established glioma cell lines, glioma tissues and normal brain. The concomitant expression of HGF, HGF activator and c-met was also detected in one glioblastoma case in vivo out of five tested.

A case of pulmonary pseudolymphoma: five years' roentgenographic observation

A patient with pulmonary pseudolymphoma whose chest X-ray shadows could be observed for over five years is reported. A 73-year-old man was admitted to our hospital in March 1993, because of abnormal shadows on a chest X-ray film. There was a solitary mass in the left upper lung field and infiltrate in the right middle and lower lung fields. These shadows had been observed on a chest X-ray film in 1988, and had been gradually growing for more than five years. Transbronchial lung biopsy (TBLB) of the left upper lobe mass resulted in a histological diagnosis of pulmonary pseudolymphoma. The shadows showed no change during the next nine months after his discharge. These findings are suggestive of the natural history of pulmonary pseudolymphoma. It seems that the process involved in this case was benign rather than malignant.

Immune response to hepatitis C virus core protein in mice

To analyse the immune response to the hepatitis C virus (HCV) core protein, we immunized mice with the protein. BALB/c (H-2d) and C3H/He (H-2k) mice were high responders, while C57BL/6 (H-2b) mice were low responders in terms of Th cell proliferative responses. All the strains showed comparable levels of antibody responses to the HCV core protein. The Th cell lines recognized residues 61-90 of the HCV core protein in the context of I-Ad (BALB/c) and residues 11-30 in the context of I-Ek (C3H/He), respectively. The Th cell lines were restricted by I-Ab in C57BL/6 mice but recognized no synthetic peptide that spanned the region, although derivative clones from the line recognized residues 1-20 and 91-110 of the HCV core protein, respectively. The Th cell lines were Th 1 subset in all three strains based on the profile of lymphokine secretion. The major B cell epitope of the protein was found to be within residues 21-40 of the HCV core protein in all three strains. These observations should be useful for better understanding of the immune response to the HCV core protein in vivo.

Angiotensin II stimulates interleukin-6 release from cultured mouse mesangial cells

Interleukin-6 (IL-6) is a multifunctional cytokine exerting a wide variety of biologic responses, including cell proliferation. Recently, IL-6 has been known to play a role in the pathogenesis of mesangial proliferative glomerulonephritis. IL-6 is now recognized as an autocrine growth factor for glomerular mesangial cells, and various inflammatory mediators have been shown to promote IL-6 release from mesangial cells. However, little is known about the noninflammatory stimuli of IL-6 release from mesangial cells. In this study, it was hypothesized that angiotensin II (AngII) is one of the noninflammatory mediators of IL-6 release in mesangial cells, and the effects of AngII on IL-6 release and mRNA expression in cultured mouse mesangial cells (CMMC) were investigated. It was demonstrated that AngII (10(-7) M or higher) caused IL-6 release and mRNA accumulation in CMMC. IL-6 release was detected at 4 h and reached a plateau at 8 h after the addition of AngII, whereas IL-6 mRNA expression peaked at 4 h. The effects of AngII on IL-6 release and gene expression were completely blocked by the AngII receptor type 1 (AT1 receptor) antagonist CV-11974. AngII and IL-6 were both shown to stimulate DNA synthesis in CMMC, and the blockade of IL-6 signaling with anti-IL-6 receptor antibody abolished the enhanced DNA synthesis induced by AngII. These results raise a possibility that the growth-promoting effect of AngII on mesangial cells is at least partially mediated by IL-6 released from mesangial cells.

Expression of transmembrane-type protein tyrosine phosphatase mRNA along rat nephron segments

Protein phosphorylation on tyrosine residues is one of the main cell signaling mechanisms. Cellular phosphotyrosyl levels are regulated by the activities of protein tyrosine kinases (PTK) and protein tyrosine phosphatases (PTPase). We have previously reported cDNA cloning of several types of PTPase from rat kidney, including LRP (leukocyte common antigen-related protein; also known as the transmembrane-type tyrosine phosphatase, i.e., RPTP alpha). LRP mRNA was shown to be abundant in the kidney; however, our understanding of the functional role of LRP in the kidney is very limited. To gain keener insight into the function of LRP in the kidney, our first approach was to reveal its mRNA distribution along rat nephron segments. Large signals were found in inner medulla by Northern blot analysis. By using a reverse transcription and polymerase chain reaction assay of individual microdissected tubule segments along the nephron [proximal convoluted tubule (PCT), medullary thick ascending limb (MTAL), cortical collecting duct (CCD), outer medullary collecting duct (OMCD), and inner medullary collecting duct (IMCD)] and glomeruli, we revealed intrarenal localization of LRP mRNA. LRP mRNA was detected in all nephron segments tested but was relatively rich in the IMCD. Rank order of the signal intensity was IMCD > PCT = OMCD > CCD > MTAL = glomeruli. Immunohistochemistry also revealed that LRP was abundant in IMCD. This pattern of expression gives rise to an interesting possibility that LRP might be involved in the specific renal tubule function, such as urinary concentrating mechanism; however, further study is required to describe the function of LRP in more detail.

Administration of phosphatidylcholine increases brain acetylcholine concentration and improves memory in mice with dementia

Studies on the effect of phosphatidylcholine administration on memory are limited. We administered egg phosphatidylcholine to mice with dementia and to normal mice and compared the differences in memory and serum choline concentration, and choline and acetylcholine concentrations and choline acetyltransferase activities of three forebrain regions (cortex, hippocampus and the remaining forebrain). Mice with dementia were produced by mating sibling mice who had impaired memory for > 20 generations. These mice had poor memory and low brain acetylcholine concentration. We administered 100 mg of egg phosphatidylcholine (phosphatidylcholine group) or water (control group) by gavage to each mouse daily for about 45 d. Control mice with dementia had poorer memory in passive avoidance performance and lower brain choline (cortex and hippocampus) and acetylcholine (hippocampus and forebrain excluding cortex and hippocampus) concentrations and lower cortex choline acetyltransferase activity than the control normal mice (P < 0.05). The administration of phosphatidylcholine to mice with dementia improved memory and generally increased brain choline and acetylcholine concentrations to or above the levels of the control normal mice. In normal mice, phosphatidylcholine treatment did not affect memory or acetylcholine concentrations in spite of the great increase in choline concentrations in the three brain regions. Serum choline concentration in mice treated with phosphatidylcholine increased to a similar level in both strains of mice, indicating that the absorption of phosphatidylcholine was not impaired in mice with dementia. The results suggest that administration of egg phosphatidylcholine to mice with dementia increases brain acetylcholine concentration and improves memory.

A helper T-cell antigen enhances generation of hepatitis C virus-specific cytotoxic T lymphocytes in vitro

A T-cell helper for generation of hepatitis C virus-specific cytotoxic T lymphocytes was studied in three patients with chronic hepatitis C. In all three, human leukocyte antigen B44-restricted cytotoxic T lymphocytes recognizing an epitope in hepatitis C virus nucleocapsid protein residues 81-100 were generated from the peripheral blood lymphocytes by repeated stimulation with a synthetic hepatitis C virus nucleocapsid peptide. The proliferative response of peripheral blood lymphocytes to hepatitis C virus nucleocapsid protein residues 1-120 was observed in one patient, and was ascribed to CD4+ T cells. The helper T cells recognized a major epitope in residues 21-40 and a minor epitope(s) in residues 81-110. They produced interferon gamma, but interleukin 4 was not detectable in the T-helper cell culture supernatants. The hepatitis C virus nucleocapsid protein residues 1-120 and the major helper T-cell epitope enhanced generation of hepatitis C virus-specific cytotoxic T lymphocytes in vitro, although the protein alone did not generate them. In the other two patients, the protein did not enhance generation of hepatitis C virus-specific cytotoxic T lymphocytes in vitro. The results suggest that a hepatitis C virus-specific helper T-cell epitope is helpful for inducing a strong specific cytotoxic T-lymphocyte response.

Establishment and characterization of a human renal carcinoma cell line MRT-1, with special reference to the production of serine proteinase inhibitors

A new human cell line MRT-1 was established from a metastatic lymph node of renal cell carcinoma of a 47 years old Japanese male. The cultured MRT-1 cells exhibit an epithelial appearance and contain lipid vacuoles in their cytoplasm in vitro. The modal chromosome number was 70. Doubling time and plating efficiency were 32.5 h and 5%, respectively (at the 47th passage). Injection of 1X10(6) MRT-1 cells beneath the renal capsule of nude mice resulted in tumor formation resembling the original tumor. Serine proteinase inhibitors produced by the cell line were analyzed. The cultured cells produced alpha 1-antitrypsin (alpha 1-AT) and plasminogen activator inhibitor-1 (PAl-1) into the conditioned medium. Most of the MRT-1 derived alpha 1-AT had lost the affinity to Concanavalin A when compared to the normal plasma alpha 1-AT.

In vivo transfection of genes for renin and angiotensinogen into the glomerular cells induced phenotypic change of the mesangial cells and glomerular sclerosis

Locally activated renin angiotensin system plays an important role in the progression of the glomerular diseases. In order to understand the local effect of overexpressed angiotensin II in the glomerulus in situ, we introduced human genes for renin and angiotensinogen into the rat kidney by hemagglutinating virus of Japan-liposome procedure. Three days after transfection human renin was detected in the glomeruli by immunohistochemistry. Seven days after transfection, extracellular matrix was expanded in the glomeruli and alpha-smooth muscle actin was expressed in the mesangial cells. These results suggest that locally activated renin angiotensin system induces glomerular sclerosis and a phenotypic change in mesangial cells.

Reverse-zymographic analysis of protease nexin-II/amyloid beta protein precursor of human carcinoma cell lines, with special reference to the grade of differentiation and metastatic phenotype

Trypsin inhibitors in serum-free conditioned media (SFCM) of various human carcinoma cell lines were analyzed by reverse zymography. Most of the cells secreted high-molecular-weight trypsin inhibitors (HMTI) larger than 100 kDa. The cell lines of colorectal carcinoma origin had a tendency to secrete HMTI whose molecular weight was a little higher than that of the other cell lines. Analysis of SFCM of subclones with different histological differentiation and metastatic/invasive potentials derived from a single pancreatic carcinoma cell line SUIT-2 showed that the HMTI activity in SFCM was correlated to the degree of histological differentiation in vivo and tended to be inversely correlated to their metastatic/invasive capabilities. Immunoblotting analysis revealed that these HMTI were protease nexin-II/amyloid beta protein precursors (PN-II/APP). Semi-quantificative reverse-transcriptase/polymerase-chain reaction study for PN-II/APP mRNAs suggested that the differences in PN-II/APP activities in SFCM between the subclones might be post-transcriptional or post-secretional events. In addition, SFCM of a highly metastatic subclone contained 43-kDa protein which reacted to anti-APP monoclonal antibody (MAb) suggesting that the subclone may have APP-degrading activity.

Cardiovascular effects of benidipine and amlodipine in isolated tissues and anesthetized dogs

Benidipine and amlodipine, 1,4-dihydropyridine calcium channel blocking drugs, are long-acting antihypertensive and antianginal drugs. In the present study, the vascular-selectivity and duration of action of benidipine were determined in vitro and in vivo, and compared with those of amlodipine. The relaxing effect of benidipine on the canine coronary artery precontracted by KCl (55 mM) was about 40 times that of amlodipine. The negative inotropic effect of benidipine in the electrically-stimulated canine right ventricular papillary muscle was about twice that of amlodipine. The potency ratios of the vasorelaxing effect in the coronary artery and the negative inotropic effect in papillary muscle were 1300 for benidipine and 67 for amlodipine, respectively. In anesthetized dogs, the maximum hypotensive effect and the duration of action of 3 micrograms/kg (i.v.) benidipine was almost the same as those of 500 micrograms/kg (i.v.) amlodipine. The duration of the hypotensive action of benidipine at 10 micrograms/kg (i.v.) was almost the same as that of amlodipine at 1500 micrograms/kg (i.v.). Amlodipine at 1500 micrograms/kg (i.v.) reduced mean blood pressure and left ventricular dp/dt max immediately after its administration, whereas such transient falls were not observed after the administration of benidipine at 10 micrograms/kg (i.v.). These results suggest that benidipine possesses a stronger vasodilating effect and a higher vascular-selectivity, compared with amlodipine.

cDNA cloning of a cytosolic protein tyrosine phosphatase (RKPTP) from rat kidney

A rat cDNA encoding a non-receptor type phosphotyrosine phosphatase (PTPase; EC 3.1.3.48) was identified. The 1608 bp cDNA contains a single open reading frame that predicts a 382 amino acid protein with M(r) 44,438. The predicted protein has no apparent signal or transmembrane sequences, suggesting that it is a cytosolic protein. The C-terminal region has a PTPase catalytic domain that has 40-50% nucleic acid homology to other known PTPases. The N-terminal region has little amino acid sequence homology to any other known sequences. The recombinant protein of the cloned cDNA expressed in Escherichia coli was shown to possess PTPase activity using myelin basic protein, tyrosine phosphorylated by p43v-abl tyrosine kinase, as a substrate.

An S-alkylating reagent with positive charges as an efficient solubilizer of denatured disulfide-containing proteins

A novel S-alkylating reagent, N-(3-bromopropyl)-N,N,N',N',N'-pentamethyl-1,3-propanedi(ammonium bromide) (TAP2-Br) which carries two positive charges in the molecule, was prepared to increase the solubility or to decrease the hydrophobicity of cysteine-containing denatured proteins (or peptides). S-Alkylation with TAP2-Br introduces two positive charges per cysteine residue, which will effectively shift the net charge of a protein in the positive direction. Disulfide-containing proteins, such as hen egg-white lysozyme, RNase A, BSA, and soybean trypsin inhibitor (Kunitz type), were reduced and S-alkylated with TAP2-Br to evaluate the potential of this reagent compared with other S-alkylating reagents such as monoiodoacetic acid, bromosuccinic acid and (3-bromopropyl)trimethylammonium bromide. The solubilities of these denatured proteins in the pH range of 2-10 indicated that S-alkylation with TAP2-Br effectively solubilized not only basic proteins (lysozyme and RNase) but also an acidic protein containing a fairly large number of cysteine residues (BSA). Moreover, the retentions of cysteine-containing tryptic peptides derived from lysozyme on reversed-phase HPLC were greatly reduced by S-alkylation with TAP2-Br. These results indicate that TAP2-Br is very useful to increase the solubility of some cysteine-containing denatured proteins and to decrease the hydrophobicity of peptides containing cysteine residue(s).

Responses of inferior collicular neurons of the FM bat, Eptesicus fuscus, to pulse trains with varied pulse amplitudes

Under free field stimulation conditions, we studied the responses of inferior collicular neurons of the FM bat, Eptesicus fuscus, to pulse trains with varied pulse amplitudes. Each pulse train consisted of 7 pulses of 4 ms delivered at 24 ms interpulse-intervals (i.e. 42 pulses/s). For a control pulse train, all pulse amplitudes were equal to a neuron's best amplitude which, when delivered in single pulses, elicited maximal number of impulses from the neuron. The amplitudes of individual pulses of the remaining pulse trains were linearly increased or decreased at a slope of 0, 14, 28, 42, 56 and 69 dB/s. All 56 inferior collicular neurons discharged to pulse trains were of two main types. Type I (N43, 77%) neurons discharged to each pulse within a train while type II (N11, 20%) neurons discharged to the first pulse of a train stimulus only. Discharge patterns of the remaining (N2, 3%) neurons changed between type I and type II when stimulated with different pulse trains. The number of impulses discharged by a neuron varied with different pulse trains. In addition, the number of impulses discharged to each pulse by type I neurons also varied among individual pulses within the train. Only 14 neurons (25%) discharged maximally to the control pulse train. Responses of the remaining neurons to other pulse trains were either 30%-120% larger than (N17, 30%) or within 30% (N25, 45%) of the control pulse train response. Furthermore, half of 56 neurons selectively discharged to a most preferred pulse train with a response magnitude which was at least 50% larger than the response to the least preferred pulse train. Possible mechanisms underlying the different discharge patterns are discussed in terms of a neuron's recovery cycle, minimum threshold and inhibitory period relative to the temporal characteristics (pulse repetition rate and amplitude) of the pulse trains.

[Bone mineral density of the lumbar spine and its relation to biological and lifestyle factors in middle-aged and aged Japanese women (Part 1). Relationship of age and menopause to bone mineral density of the lumbar spine measured by dual-energy X-ray absorptiometry]

Bone mineral density (BMD) of the lumbar spine in 198 community-dwelling Japanese women aged 35 years and over was measured by dual-energy X-ray absorptiometry to investigate the effects of aging and menopause on BMD. A highly significant negative correlation between age and BMD was observed in postmenopausal women as widely accepted. We found a weak but statistically significant negative correlation between age and BMD in even premenopausal women, suggesting that their bone loss had commenced before menopause. Marked decrement in BMD was seen during the first ten years after menopause. Menopause clearly accelerated bone loss in the lumbar spine. Two-way analysis of variance of BMD on age and menopausal status showed that these explanatory variables had a significantly decreasing effect on BMD independently of each other. Menopausal status had a greater sum of squares than age, which suggested that menopause played a greater role in bone loss than did aging. Early menopause has been implied as one of the risk factors for bone loss. The women aged 50 to 59 having encountered menopause before 49 years old exhibited significantly lower BMD than those of similar age who experienced menopause at age 49 and older. This difference in BMD was not observed in the women aged 60 and over. Early menopause was no more likely to be a risk factor for bone loss in the elderly women. We conclude that bone loss in the lumbar spine begins before menopause and is accelerated markedly by menopause for about ten years, and that menopause has a greater decreasing effect on the bone mass than does chronological age while each of them has an independent effect on the bone mass decrement.

Molecular organization of bacteriochlorophyll in chlorosomes of the green photosynthetic bacteriumChloroflexus aurantiacus: Studies of fluorescence depolarization accompanied by energy transfer processes

Examination was made of changes in fluorescence polarization plane by energy transfer in the chlorosomes of the green photosynthetic bacterium,Chloroflexus aurantiacus. Fluorescence anisotropy in the picosecond (ps) time region was analyzed using chlorosomes suspended in solution as well as those oriented in a polyacrylamide gel. When the main component of BChlc was preferentially excited, the decay of fluorescence anisotropy was found to depend on wavelength. In the chlorosome suspension, the anisotropy ratio of BChlc changed from 0.31 to 0.24 within 100 ps following excitation. In the baseplate BChla region, this ratio decreased to a negative value (-0.09) from the initial 0.14. In oriented samples, the degree of polarization remained at 0.68 for BChlc, and changed from 0.25 to -0.40 for the baseplate BChla by excitation light whose electric vector was parallel to the longest axis of chlorosomes. In the latter case, there was a shift from 0.30 to -0.55 by excitation perpendicular to the longest axis. Time-resolved fluorescence polarization spectra clearly indicated extensive changes in polarization plane accompanied by energy transfer. The directions of polarization plane of emission from oriented samples were mostly dependent on chlorosome orientation in the gel but not on that of the polarization plane of excitation light. Orientations of the dipole moment of fluorescence components was consistent with that of absorption components as determined by the linear dichroism (Matsuura et al. (1993) Photochem. Photobiol. 57: 92-97). A model for molecular organization of BChlc anda in chlorosomes is proposed based on anisotropic optical properties.

The effects of daily wear of rigid gas permeable contact lenses treated with contact lens care solutions containing preservatives on the rabbit cornea

We evaluated the effects on the rabbit cornea of daily wear of rigid gas permeable (RGP) contact lenses treated with preserved care solutions by measuring concomitant tear lactate dehydrogenase (LDH) activity followed by in vivo tandem scanning confocal microscopy (TSCM). In vivo morphologic changes were confirmed by in vitro scanning electron microscopy (SEM). Two standard commercial RGP lens wetting and soaking solutions from the same manufacturer were tested: solution A with 0.004% benzalkonium chloride (BAK) and solution B with 0.003% chlorhexidine digluconate (CHX) and 0.002% thimerosal. Two experimental PBS-based wetting and soaking solutions were also tested: solution C with 0.005% BAK and 2% hydroxypropylmethylcellulose (HPMC) and solution D with 0.005% BAK without HPMC. Instillation of solution A without contact lens wear caused significant (P < 0.01) increases in desquamation of the superficial corneal epithelium and tear LDH activity compared with control eyes. After 3 weeks of RGP contact lens daily wear (8 hours/day), modified Draize scores of ocular surface lesions on the eyes wearing RGP lenses treated with solution A increased according to the duration of lens wear. Solution B did not produce significant change. With daily wear for 4 days (8 hours/day), RGP lenses treated with solution C and solution D produced increased corneal epithelium desquamation and an increase of LDH activity in tears. These effects were greater with HPMC (solution C) than without HPMC (solution D).(ABSTRACT TRUNCATED AT 250 WORDS)

A new testicular feminization mutation found in C57BL/6J mice

A new testicular feminization (Tfm) mutation found in the inbred strain of mice, C57BL/6JJms, was separated from the original line and established as a mutant strain. This line was named C57BL/6JJms-TfmJms. The process of discovery and breeding are described. Body weights were compared among male, normal virgin female and Tfm mice between 5 and 40 weeks of age. Tfm mice were generally intermediate in weight between male and virgin female mice. This result is different from that previously reported for the Tfm mouse strains and may be of interest in comparison between Tfm mice and their normal litter mates.

The effects of frequently rotating shiftwork on sleep and the family life of hospital nurses

The effects of three frequently rotating shifts in an irregular sequence on the daily activities of 239 Japanese female hospital nurses were studied by the time-budget method. The nurses recorded their daily activities for several consecutive days. The questionnaire was returned by 80.8% of the participants, and recordings of 1016 days were analysed. A two-way analysis of variance clarified that the shift combination influenced the daily activities. The most distinct result was that nurses spent significantly more time on free-time activities on the day when they worked the night shift followed by the evening shift than they did on the day when they worked any other shift combination. Nurses offset sleep deprivation either by sleeping during the day before and after working the night shift (82-100%) or by sleeping 2 to 4 h later in the morning after working the evening shift and on days off. There was a strong positive correlation between total sleep time (including day sleep) and the length of the interval between two consecutive shifts (r = 0.95, p < 0.001). This result suggests that more than 16 h between work shifts is required to allow more than 7 h of total sleep time. In an analysis by household status, nurses who had young children (average age, 2.8 years) slept less and spent less time on free-time activities than did other nurses.

[A case of multiple myeloma associated with a large subcutaneous mass in the frontal region]

A case of multiple myeloma having plasmacytoma in the frontal bone and clivus is reported. A 68-year-old female was referred to our hospital because of a subcutaneous mass in the frontal region. She was diagnosed as having multiple myeloma 7 years ago and had been treated with chemotherapy. On admission, severe anemia, hyperproteinemia and elevation of serum lambda type immunoglobulin G (IgG) were pointed out. Plain skull X-rays showed numerous punched out lesions with a large bone defect of the frontal bone. CT scan and MRI revealed a mass lesion in the clivus in addition to a large epidural tumor in the frontal region. The encapsulated frontal epidural tumor was totally resected and cranioplasty was performed with resin. Histological diagnosis was plasmacytoma of IgG lambda type. The postoperative course was uneventful, and chemotherapy was continued. There was no tumor recurrence in the frontal region and no neurological deterioration, but she died of DIC 15 months after the operation. Twenty seven cases in the literature of multiple myeloma forming cranial or intracranial plasmacytoma were briefly reviewed. Although the prognosis of such cases is poor, total resection of medullary plasmacytoma is warranted especially in multiple myeloma patients who don't have another extramedullary plasmacytoma or plasma cell leukemia.

Class I-restricted cytotoxic T lymphocytes are directly cytopathic for their target cells in vivo

Although CD8-positive, class I-restricted CTL play a critical role in viral clearance and immunopathology in many model systems, they have not been shown to directly kill their target cells in vivo at the single cell level. Using a hepatitis B surface Ag transgenic mouse model of class I-restricted, CTL-mediated liver disease, we now demonstrate that CD8-positive, Ld-restricted hepatitis B surface Ag-specific CTL bind and kill their target cells in vivo by triggering them to undergo degenerative cytologic changes compatible with apoptosis. Unexpectedly, the data also indicate that the pathologic consequences of this direct, Ag-specific CTL effect are much less severe than the cytodestructive, Ag-nonspecific inflammatory response that they induce when they are activated by Ag recognition.