FK506 and cyclosporin A inhibit granulocyte/macrophage colony-stimulating factor production by mononuclear cells in asthma

Bronchial asthma is associated with eosinophilic inflammation and expression of T-cell-derived cytokines, which influence eosinophilic function. FK506, a newly established immunosuppressive agent, may have potential as a therapeutic instrument for asthma because of its suppressive effect on T-cell activation. To assess this, we compared the inhibitory effects of FK506 and cyclosporin A on production of granulocyte/macrophage colony-stimulating factor and interleukin-5 by interleukin-2- or Dermatophagoides farinae-stimulated mononuclear cells from patients with asthma, and their contribution to proliferation and survival of eosinophils in vitro. FK506 inhibited granulocyte/macrophage colony-stimulating factor production by stimulated mononuclear cells from asthma patients at lower concentrations than cyclosporin A. Both drugs inhibited eosinophil proliferation and survival activity from mononuclear cells at comparable concentrations. Interleukin-5 production by stimulated mononuclear cells was also inhibited both by FK506 and cyclosporin A. We conclude that both FK506 and cyclosporin A have potential for therapy of bronchial asthma.

Influence of systemic chemotherapy on anti-P-glycoprotein antibody-dependent cell-mediated cytotoxicity in patients with small cell lung cancer

Anti-P-glycoprotein antibody (MRK-16)-dependent cell-mediated cytotoxicity (ADCC) by blood mononuclear cells (MNC) was examined in patients with small cell lung cancer (SCLC) before and after systemic chemotherapy. The effect of in vitro treatment of MNC with interleukin (IL)-2 and macrophage-colony-stimulating factor (M-CSF) was also examined. The ADCC reaction was assessed by a 6 h 51Cr-release assay using a multidrug-resistant (MDR) SCLC cell line (H69/VP cells). The MRK-16 monoclonal antibody was able to augment spontaneous cytotoxicity by MNC, even in SCLC patients. Pretreatment of MNC with IL-2 significantly augmented their ADCC ability in SCLC patients, while M-CSF had no effect on ADCC activity. After the first cycle of systemic chemotherapy, the ADCC activity tended to decline, but ADCC of MNC pretreated with IL-2 was not affected. The results suggest that anti-P-glycoprotein antibody, in combination with a cytokine such as IL-2, may be therapeutically useful against human SCLC resistant to chemotherapeutic drugs.

[Magnetic resonance imaging of renal lymphoma with computed tomography correlation]

The magnetic resonance (MR) imaging and computed tomography (CT) findings in four patients (five kidneys) with non-Hodgkin's lymphoma involving the kidneys and perirenal spaces are presented. The patterns of disease in each case were as follows: bilateral renal nodules, infiltration in the perirenal space, infiltration in the perirenal space with renal involvement, and direct invasion from contiguous retroperitoneum. On plain CT, the lesions showed slight hyperdensity (three kidneys) and isodensity (two kidneys) as compared with normal renal parenchyma. But all lesions appeared as hypodense masses with more definite margins after contrast enhancement. MR imaging findings showed iso- or slight hypointense masses on T1-weighted images and definite hypointense masses on T2-weighted images as compared with the signal intensity of the renal cortex. Dynamic imaging and conventional delayed T1-weighted imaging following Gd-DTPA injection showed no significant enhancement of the lesions. In comparison with contrast enhanced CT, despite its poorer resolution, T2-weighted MR imaging showed nearly the same accuracy in the evaluation of number and extent of the lesions without contrast medium administration. MR imaging was also useful to evaluate the patency of vessel lumen surrounded by tumor mass and to determine the location and extent of huge lesions by its multiplanar imaging capabilities.

[Radiological and anatomical investigation of calcific tendinitis of the gluteus maximus tendon]

The radiological findings in four cases of gluteus maximus tendinitis were retrospectively analyzed. All the patients underwent radiographic, CT and MRI examinations. Amorphous or round calcifications were detected on lateral radiographs in three cases, and on CT in all cases. A small cortical erosion was observed in three cases on both radiographs and CT. MRI showed a thickened gluteus maximus tendon, but no other specific features. In the supine position, which is common in routine CT and MRI studies, the calcific deposits appeared to be distributed along the vastus lateralis muscle tendon. To correlate these radiographic observations with the topographic anatomy of the tendon's insertion, we investigated 14 thighs of seven cadavers, and clarified that the tendon's insertion was the main component of the lateral femoral intermuscular septum. Consequently we performed MRI on a volunteer in a prone position who was asked to maintain contraction of the gluteus maximus and quadratus femoris muscles. The images obtained showed clearly that the gluteus maximus tendon was directed dorsally. In conclusion, radiography and CT are the modalities of choice for diagnosis of this entity. Additionally, radiologists should be aware that the gluteus maximus tendons are directed laterally as a main part of the lateral femoral intermuscular septum on routine CT and MRI.

Serum levels of interleukin 6 in patients with lung cancer

Serum interleukin 6 (IL-6) levels were measured in 75 patients with lung cancer and in 20 patients with benign lung diseases. IL-6 was detectable in 29 patients with lung cancer (39%), but was not detectable in any of the patients with benign lung diseases. Serum C-reactive protein levels and plasma fibrinogen levels were significantly higher and serum albumin concentration was significantly lower in lung cancer patients with detectable serum IL-6 levels than in those without detectable serum IL-6 levels and in patients with benign lung diseases. On the other hand, no significant difference was observed in blood platelet counts in these three groups. Moreover, serum IL-6 levels were not significantly different in lung cancer patients with or without clinically demonstrated distant metastasis. These results suggest that IL-6 may be a mediator of various reactions including an inflammatory response in lung cancer patients.

[Trial of a small image network system in a radiology department of an university hospital]

This paper describes the construction of an image network system in Shinshu University Hospital, and some of its current issues and advantages. Our discussion is based on our experience with a PACS system. SAIPACS, which was installed in 1990 for use in clinical conferencing and pre- and post-graduate education, and with a new CT and MRI network, which was subsequently introduced in 1993. The SAIPACS interconnects eight digital imaging modalities, including CT, MRI, XTV-DR (including digital tomosynthesis), FCR, nuclear medicine (RI), DSA, US, and a film digitizer (FD), with a workstation. Transmission time from the magnetic disk of each imaging modality to the SAIPACS image disk is not rapid enough. Therefore, we need to select images for transfer that are pertinent to our specific purpose, to complete image transmission within a practically acceptable period of time. The new CT/MRI network is composed of two CT units, two MRI systems, an image processing unit and a Universal Gateway. It provides faster image transmission than the SAIPACS system, because there is no need to reform image data to send them in a reversible compressed form. A versatile network system connected to the SAIPACS and CT/MRI network enables digital image data to be processed and edited and images to be transferred back to SAIPACS for clinical or educational use.

Induction of cyclooxygenase-2 is responsible for interleukin-1 beta-dependent prostaglandin E2 synthesis by human lung fibroblasts

Because interleukin-1 beta (IL-1 beta) increases the synthesis of prostaglandin E2 (PGE2) in human lung fibroblasts, the effect of IL-1 beta on the expression of two isozymes of cyclooxygenase (cyclooxygenase-1 and -2) in human embryonic lung fibroblasts (IMR-90) was investigated in terms of three parameters (PGE2 release, cyclooxygenase activity, and mRNA). When the cells were incubated with IL-1 beta, both the PGE2 release to the culture medium and the cyclooxygenase activity in the cell lysate increased in a dose- and time-dependent manner, and both were inhibited by NS-398 (a cyclooxygenase-2-specific inhibitor). Dexamethasone and interleukin-4 (IL-4) inhibited the IL-1 beta-induced PGE2 synthesis; the former inhibited the IL-1 beta-induced cyclooxygenase activity whereas the latter failed. As analyzed by Northern blot, cyclooxygenase-1 mRNAs (3.0 Kb and 5.0 Kb) were detected with resting cells and did not increase by the addition of IL-1 beta. In contrast, the cyclooxygenase-2 mRNA (4.4 Kb) was undetectable with resting cells, but was increased dramatically up to 4 to 8 h by the addition of IL-1 beta. Dexamethasone inhibited the IL-1 beta-induced mRNA expression of cyclooxygenase-2 whereas IL-4 failed. These results indicate that IL-1 beta induces cyclooxygenase-2 rather than cyclooxygenase-1 in IMR-90 cells and this induction is responsible for the augmentation of PGE2 production stimulated with IL-1 beta. However, the inhibition of the IL-1 beta-induced PGE2 synthesis by IL-4 was not mediated by the down-regulation of cyclooxygenase-2.

Differential effects of anti-inflammatory cytokines (IL-4, IL-10 and IL-13) on tumoricidal and chemotactic properties of human monocytes induced by monocyte chemotactic and activating factor

The effect of recombinant human IL-4, IL-10, and IL-13 on the chemotaxis and antitumor activity of human blood monocytes induced by monocyte chemotactic and activating factor (MCAF) was examined. MCAF alone did not induce monocyte-mediated cytotoxicity against human melanoma (A375-M) cells whereas it significantly enhanced the cytotoxicity by norMDP-stimulated monocytes. MCAF, unlike IFN-gamma, had no priming effect on monocyte activation by norMDP. MCAF acted with norMDP or LPS to enhance the production of both IL-1 beta and TNF-alpha. Enhanced cytotoxicity of monocytes stimulated with MCAF plus norMDP was reduced by IL-1 receptor antagonist and anti-TNF-alpha antibody. IL-4, IL-10, and IL-13 suppressed the generation of antitumor activity and cytokine production (IL-1 beta and TNF-alpha) of monocytes stimulated with MCAF plus norMDP or LPS. Chemotaxis of monocytes induced by MCAF was not affected by norMDP or any of the anti-inflammatory cytokines (IL-4, IL-10, and IL-13). Moreover, the pretreatment of monocytes with anti-inflammatory cytokines did not suppress monocyte-chemotaxis. These findings suggest that in vivo recruitment and anti-tumor expression of blood monocytes induced by MCAF may be differently regulated by anti-inflammatory cytokines in vivo.

Contrasting effect of interleukin-13 on interleukin-1 receptor antagonist and proinflammatory cytokine production by human alveolar macrophages

We investigated the effect of interleukin-13 (IL-13) on production of IL-1 receptor antagonist (IL-1ra) and proinflammatory cytokines by human alveolar macrophages (AM). AM were obtained by bronchoalveolar lavage from healthy donors. The production of IL-1ra and proinflammatory cytokines, such as IL-1 beta, IL-6, and tumor necrosis factor-alpha (TNF-alpha), were quantitated by enzyme immunoassays. AM spontaneously produced IL-1ra, and this production was significantly augmented by IL-13. On the other hand, IL-13 alone did not affect production of proinflammatory cytokines by freshly isolated AM. Upon stimulation with lipopolysaccharide (LPS), AM produced a significantly amount of proinflammatory cytokines as well as IL-1ra, but this production was suppressed by IL-13 in a dose-dependent manner. In contrast, IL-13 caused a small but reproducible increase in LPS-induced IL-1ra production. These regulatory effects of IL-13 were also observed in blood monocytes and macrophages generated in vitro by maturation of blood monocytes with granulocyte/macrophage colony-stimulating factor. These observations suggest that IL-13 may act as an anti-inflammatory cytokine through regulation of cytokine production by AM in the lung.

Human alveolar macrophages augment natural killer cell stimulatory factor (interleukin-12)-inducible killer activity from autologous blood lymphocytes

Interleukin-12 (IL-12), also known as natural killer cell stimulatory factor (NKSF), was found to induce cytotoxic activity from human blood T cells and NK cells. The present study was undertaken to examine the effect of human alveolar macrophages (AM) on induction by IL-12 cytotoxic cells from blood lymphocytes. AM were obtained by bronchoalveolar lavage from healthy donors. Highly purified lymphocytes (> 99%) and monocytes (> 90%) were also isolated by centrifugal elutriation from peripheral blood of the same donors. Cytotoxicity of lymphocytes was measured by 4-h 51Cr release assay. IL-12 stimulated blood lymphocytes to produce interferon gamma (IFN gamma) and tumor necrosis factor alpha (TNF alpha), and this effect was augmented by co-cultivation with monocytes or AM. AM-upregulated induction of cytotoxic lymphocytes was stimulated with IL-12, and this effect was significantly abrogated by addition of antibodies against IFN gamma and TNF alpha. Induction by IL-12 of IFN gamma production and cytotoxic activity of CD8+ cells was also augmented by co-cultivation with monocytes or AM. AM were more effective than monocytes in augmenting the cytotoxic activity of IL-12-stimulated lymphocytes and CD8+ cells. These observations suggest that in situ induction of IL-12-stimulated cytotoxic cells in the lung may be regulated by complex cytokine networks, depending on participation of monocytes and alveolar macrophages.

MR appearance of periosteal chondrosarcoma of the foot

OBJECTIVE

To assess the role of MRI in evaluating periosteal chondrosarcoma in the foot, an anatomically complicated location.

MATERIALS AND METHODS

Three cases of surgically and histologically confirmed periosteal chondrosarcomas occurring in the foot (58-year-old woman, 57-year-old woman, and 63-year-old man) were retrospectively reviewed with an emphasis on MR findings.

RESULTS

Magnetic resonance successfully delineated the hypovascular nature and lobulating pattern of the lesion suggesting the cartilaginous component, the periosteal location with sparing bone marrow, and the extent of involvement of adjacent structures. These findings were either not seen or less clearly seen on CT in the former two cases.

CONCLUSION

In cases of periosteal chondrosarcomas in the foot MRI can play a significant role both in the characterization of the lesion and in planning surgical therapy.

[High-resolution teleradiology system based on ISDN and small computer]

A high-speed, high-resolution teleradiology system based on the Integrated Services Digital Network (ISDN) is described. The LAN at Saku Central Hospital and the Radiological Department at Shinshu University Hospital (60 km) are interfaced to a Macintosh computer with an image digitizer, interactive display, and network interface. The transmission time for a digitized high-resolution radiographic image with 4.39 megabytes was 358 seconds using a 128 kbps (kilobit-per-second) channel (B1 + B2), and the mean transmission rate was 98.1 kbps. Teleradiology conference is also available using this system. Radiologists can observe the same high-resolution images on the CRT screen simultaneously at two different remote hospitals, indicating a point of interest on the image by means of a mouse cursor. Graphical data of interest to the radiologists are also transmitted and displayed on the CRT.

[High-speed/high resolution teleradiology system based on university microwave network]

A high-speed, high-resolution teleradiology system with full duplexing based on the Shinshu University Video and Communication Network System (SUNS) using Giga-Herz microwaves is described. The LAN at Nagano Red-Cross Hospital and The Radiology Department of Shinshu University Hospital are interfaced to a personal computer with a laser film digitizer, interactive display, and network interface. The throughput per digitized high-resolution radiographic image was 65 sec, and the mean transmission rate was 805 kilobit per sec. Teleradiology conferencing is also possible with this system. Radiologists at both hospitals interactively observe the same high-resolution images on the CRT screen using mouse cursor synchronization.

[Study of X-ray filter and peak kilovoltage in film-screen chest radiographs in regard to detection of simulated pulmonary nodules: comparison between film-screen combination and FCR]

We compared the ability of standard film-screen chest radiographs to detect simulated pulmonary nodules. The radiographs were taken with different X-ray filters and tube voltages. Detection capability was analyzed utilizing receiver operating characteristic (ROC) curves formed from the interpretation of six readers. Nodule detection was slightly better in images obtained with a tube voltage of 135 kVp than with one of 100 kVp (not statistically significant). Approximately equal detection performance was shown by a conventional film-screen system and FCR with three X-ray filter sets: a copper filter backed by aluminium, a tungsten filter backed by yttrium and aluminium, and a lead filter backed by yttrium and aluminium. Results showed less X-ray exposure with the two latter filter sets. Unenhanced FCR images taken with approximately the same X-ray exposure as conventional radiographs showed nearly equal ability to detect the simulated nodules.

[Study of X-ray filter and peak kilovoltage in Fuji Computed Radiography in regard to the detection of simulated pulmonary nodules]

To determine a suitable combination of X-ray filter and tube kilovoltage for Fuji Computed Radiography (FCR), to provide better detection of pulmonary nodules and reduce patient exposure, we compared observer performance with different X-ray filters and tube voltages. Radiographs were obtained with a copper filter backed by aluminium, with a tungsten filter backed by yttrium and aluminium, and with a lead filter backed by yttrium and aluminium, at both 100 kVp and 135 kVp. Observer performance in detecting simulated lung nodules, which were placed on the posterior aspect of a chest phantom, was compared using receiver operating characteristic (ROC) techniques for each combination of the X-ray filter and tube voltage. The results of the study indicated that 1) nodule detection was superior for the images obtained with 135 kVp as compared with 100 kVp; 2) approximately equal detection rates were obtained for the three X-ray filter sets, although results with the tungsten filter were slightly inferior to the other two filters; and 3) the absorbed dose may be reduced by 30% with the use of a lead filter backed by yttrium and aluminium compared with a copper filter backed by aluminium. We conclude that chest radiography with FCR should preferably be conducted with a higher kilovoltage, e.g., 135 kVp rather than 100 kVp, to ensure a higher detection rate of pulmonary nodules and in conjunction with a lead filter backed by yttrium and aluminium to reduce X-ray exposure to the patient.

[Micro-wave local area network for radiological image transmission]

Shinshu University consists of five campuses in different locations, a situation that presents some problems in communication. To solve this problem, the Shinshu University Video and Data Network System (SUNS), which includes a high-speed audio-visual transfer function, has been developed and utilized for pre- and postgraduate education, administrative teleconferences, and local telephone (PBX) and Fax services. In 1988, a cooperative group for the study of radiographic image processing was organized, consisting of staff members of Shinshu University Hospital in Matsumoto, the Faculty of Engineering in Nagano (75 km from Matsumoto) and the Faculty of Textile Science and Technology in Ueda (45 km from Matsumoto). The system has been developed with a pair of personal computer (PC)-based interactive image workstations and high-speed digital telecommunication interfaces to the SUNS. A transmission time of 878 kbps has been attained, including the time needed for read/write onto the PC hard disk. Image data thus transferred from the hospital have been utilized for the study of image processing by researchers in the Faculty of Engineering, and the processed images have been sent back to the hospital for evaluation of clinical efficacy of the processing by diagnostic radiologists. This kind of microwave network is a promising alternative for high-speed data transmission for radiological images and their processing.

Meeting report of the International Symposium of Molecular Cell Biology of Macrophages '94

The International Symposium of Molecular Cell Biology of Macrophages '94 was held on February 10-11, 1994 at Kanazawa University, Kanazawa, Japan. Fifteen speakers including 4 speakers from Europe and the United States were invited to this symposium. In spite of unusual heavy snow and chilly weather, 150 macrophage scientists gathered and had hot discussions. In the meeting reception, a special recognition speech entitled "Dawn of Cytokines--Discovery of a Blastogenic Factor in the Early 1960's" was given by a discoverer of blastogenic factor, Dr. Shinpei Kasakura. This symposium was initiated in 1991 with the intention of bringing together experts of macrophage investigation once a year to discuss progress in the field of molecular cell biology of macrophages.

Spontaneous production of interleukin-8 by human lung cancer cells and its augmentation by tumor necrosis factor alpha and interleukin-1 at protein and mRNA levels

A cell-to-cell interaction between tumors and host inflammatory cells is important for the subsequent cancer progression or regression. We examined the expression of interleukin-8 (IL-8) mRNAs by 9 human lung cancer cell lines and the influences of cytokines on IL-8 production and its gene expression. Substantial expressions of IL-8 gene were detected in 3 lung cancer cell lines (RERF-LC-OK, Lu-134-A-H, YO-88 cells). Moreover, 4 lung cancer cell lines (RERF-LC-MS, RERF-LC-OK, A549 and YO-88) were used to examine the effects of exogenous cytokines--interleukin-1 beta (IL-1 beta), tumor necrosis factor alpha (TNF-alpha) and granulocyte-macrophage colony-stimulating factor--on IL-8 production by the cells at protein and gene levels. TNF-alpha and IL-1 beta significantly augmented the levels of mRNA expression for IL-8 and its production. These observations indicate that tumor-derived IL-8 may be important in recruiting inflammatory neutrophils and promoting interaction between lung cancer and inflammatory cells.

[Cerebral digital tomosynthetic angiography for planning stereotactic biopsy of brain tumor]

We used cerebral digital tomosynthetic angiography for planning the probe trajectory of stereotactic biopsy of brain tumors in four patients. The probe trajectory was basically planned by MRI examinations. However, cerebral digital tomosynthetic angiography demonstrated detailed three-dimensional vascular anatomy around the brain tumors, and therefore was very helpful in revising the planned trajectory when there was a fairly large vessel likely to cross with it.

Accentuated temporal line on the frontal skull radiograph: a sign of hyperparathyroidism

PURPOSE

To determine the importance of a temporal line (the marginal line for the attachment of the temporal muscle to the skull) that is accentuated on frontal skull radiographs of hyperparathyroid patients owing to subligamentous bone resorption under the temporal muscle.

MATERIALS AND METHODS

Radiographs from skeletal surveys of 134 surgically treated patients with primary (n = 102) or secondary (n = 32) hyperparathyroidism (HPT) and frontal skull radiographs of 63 age-matched control patients were reviewed.

RESULTS

An accentuated temporal line was the most frequent finding (29.4% of cases) in primary HPT, followed by subperiosteal bone resorption in the hand (8.6%), salt-and-pepper appearance of the skull (3.5%), and rugger-jersey spine (1.1%). In secondary HPT, an accentuated temporal line became less obvious as subperiosteal bone resorption advanced. This finding was not seen in the control group.

CONCLUSION

An accentuated temporal line is another radiographic indication of bone resorption in HPT.

Induction mechanism of human blood CD8+ T cell proliferation and cytotoxicity by natural killer cell stimulatory factor (interleukin-12)

Natural killer cell stimulatory factor (NKSF/IL-12) has been found to induce cytotoxic activity of human blood T cells. In the present study, the effect of NKSF on induction of cytotoxic CD8+ T cells in the presence or absence of monocytes was examined. Highly purified lymphocytes (> 99%) and monocytes (> 90%) were isolated by centrifugal elutriation from peripheral blood of normal donors. Then, CD8+ cells were isolated with antibody-bound magnetic beads from purified lymphocytes. The cytotoxicity of CD8+ cells was measured by 51Cr release assay for 4 h. NKSF enhanced the proliferative response of CD8+ cells stimulated with suboptimal concentrations of interleukin-2 (IL-2), but rather inhibited their proliferative and cytotoxic responses on stimulation with an optimal concentration of IL-2. NKSF stimulated CD8+ cells to produce interferon gamma (IFN gamma) irrespective of the presence of added IL-2, and this effect was augmented by co-cultivation with monocytes. Blood monocytes upregulated induction of cytotoxic CD8+ cells stimulated with NKSF alone, and this effect was abolished by addition of antibody against IFN gamma, but not of antibody against tumor necrosis factor alpha. Induction of NKSF-inducible cytotoxic CD8+ cells was inhibited by addition of transforming growth factor beta, but not of IL-4. These observations suggest that in situ induction of NKSF-stimulated cytotoxic CD8+ cells may be regulated by complex cytokine networks, depending on the participation of monocytes.

[Diffuse slow washout pattern (DSWO) on exercise stress thallium-201 myocardial SPECT: correlative study with coronary arteriography and the related clinical factors]

DSWO was shown on bull's eye images of 98 of 1234 patients suspected of having coronary artery disease and examined with thallium-201 myocardial SPECT imaging. Fifty-eight of these 98 patients underwent coronary arteriography, and comparison studies were performed between the bull's eye SPECT images, the results of coronary arteriography and the laboratory data. DSWO was found in 11 of 58 cases (19.0%) of single vessel disease (1VD), 18 of 58 cases (31.0%) of double vessel disease (2VD) and 21 of 58 cases (36.2%) of triple vessel disease (3VD). Three of 58 cases (5.2%) of stenosis of a coronary artery less than 75% of its normal diameter (N group) also showed DSWO. DSWO was closely related with multiple vessel disease, as has been indicated by previous reports, but we also found another patient group that showed minor coronary arterial change (1VD and N group) and manifested DSWO. Based on the study of laboratory data, we clarified that this group of patients tended to show accompanying hypertension and hyperlipidemia as factors influencing the appearance of DSWO. DSWO was accompanied by hypertension and hyperlipidemia in 54.5% and 45.5% in 1VD. These values were higher than those in the 2VD and 3VD cases, which were 33.3% and 38.9% in 2VD, and 19.0% and 28.6% in 3VD, respectively. Hypertension and hyperlipidemia appeared to play an important role in causing DSWO by interfering with coronary circulation.

[A case of Larsen syndrome with severe cervical cord compression]

We reported a case of Larsen syndrome with cervical cord compression. She had a flattened face, bilateral joint dislocations of the elbows, hips and knees, and equinovalgus deformity on the feet. At first she had flaccidity of the upper and lower limbs, she gradually developed spastic. On laboratory examination, CSF protein was elevated. EMG showed fibrillation. In short latency somatosensory evoked potential (SSEP), N 20 was not detected. MRI showed a severe cervical cord compression. Cervical spine deformity has been often described in the previous reports on Larsen syndrome, but cervical cord compression demonstrated by MRI was reported in only one case. We should take into consideration this risk associated with Larsen syndrome.

Muscle histochemistry in the Prader-Willi syndrome

In a follow-up study of 259 floppy infants of undetermined cause in my laboratory, 11 patients were later diagnosed as having the Prader-Willi syndrome (PWS). To clarify the pathogenesis of muscle hypotonia in PWS, I examined muscle biopsies by histochemical and morphometric methods and the results were compared with those obtained from floppy infants with only mental retardation but with no other features. The histochemical abnormalities of PWS included (i) fiber size variation of both type 1 and 2 fibers, (ii) type 2 fiber atrophy, (iii) increased numbers of type 2C fibers, and (iv) decreased numbers of type 2B fiber. Although muscle hypotonia in PWS has been thought to be due to central nervous system abnormality, my findings suggest that primary muscle pathology, including muscle fiber immaturity and abnormal muscle fiber type distribution, at least in part, plays a role in muscle hypotonia and weakness.

Interleukin-10 is a potent inhibitor of tumor cytotoxicity by human monocytes and alveolar macrophages

The effects of purified human interleukin-10 (IL-10) on the expression of antitumor activity of human monocytes and alveolar macrophages (AMs) obtained by centrifugal elutriation and bronchoalveolar lavage, respectively, from the same healthy donors were examined. Monocytes and AMs were incubated for 16 h in medium with lipopolysaccharide (LPS) in the presence or absence of IL-10 or IL-4, and then their tumoricidal activity was assayed by measuring 125I-IUdR release from human melanoma (A375) cells. Addition of IL-10 to cultures of monocytes or AMs with LPS resulted in dose-dependent suppression of their cytotoxicity against A375 cells, the suppression of the activity of monocytes being the higher. IL-10 also suppressed the synergistic effects of interferon-gamma and desmethyl muramyldipeptide in activation of monocytes. IL-10 inhibited the early induction phase of monocyte activation but not the effector phase (monocyte-mediated cytotoxicity). IL-10 plus IL-4 inhibited the antitumor activities of AMs and monocytes much more than either IL-10 or IL-4 alone. IL-10 and IL-4 at suboptimal concentrations also showed synergistic inhibitory effects. These findings suggest that IL-10 may be important in vivo in down-regulating the antitumor activities of monocytes and AMs in the lung by inhibiting their productions of antitumor effector molecules.