Lymphoid hyperplasia of the large intestine: a case report with immunohistochemical and gene analysis

A case of lymphoid hyperplasia arising in the large intestine of a 54-year-old woman is described. Barium enema X-ray and colonoscopic examination revealed multiple small polyps in the right side of the colon. Pathological findings from forceps biopsy revealed similar features to a mucosa-associated lymphoid tissue (MALT) lymphoma. A right hemicolectomy with mesenteric lymph node dissection was carried out. Histological sectioning demonstrated hypertrophic lymphoid follicles with well-formed germinal centers. Occasionally, lymphocytes infiltrated the crypts, in a way similar to that found in lymphoepithelial lesions, which was suggestive of a MALT lymphoma diagnosis. Cryptitis was also observed in the lamina propria. Immunohistochemically, proliferating lymphocytes were positive for CD20 (L26) and negative for CD45RO (UCHL-1). Analyses of immunoglobulin gene (IgHJH) rearrangement could not detect any monoclonality in these cells. These findings suggested that the present case should be categorized as lymphoid hyperplasia rather than lymphoma.

Estimate of gas transfer rates of an intravascular membrane oxygenator

An asymmetric hollow fiber membrane was prepared from a newly synthesized fluorinated aromatic polyimide (6FDA-6FAP) by using a dry/wet phase inversion process. The membrane was used in a membrane oxygenator over a long period of time. In this study, the potential of the membrane for intravascular membrane oxygenation (IVOX) was studied in respect to oxygen transfer. The gas permeance of the membrane and three commercially available hollow fiber membranes for membrane oxygenators was measured in a gas-gas system and a gas-liquid system and discussed relative to the membrane structures. The oxygen transfer rates of the IVOX devices using these four membranes were estimated by a mathematical kinetic model, with the oxygen permeance measured in the gas-liquid system. The results showed that the device using the 6FDA-6FAP hollow fiber membrane has the highest oxygen transfer rate and is believed to be applicable to IVOX. The methods to determine oxygen transfer rate of a hollow fiber membrane and the mathematical kinetic model, are useful for developing a hollow fiber membrane and a device for oxygenation.

The role of vascular endothelial growth factor in human dental pulp cells: induction of chemotaxis, proliferation, and differentiation and activation of the AP-1-dependent signaling pathway

Vascular endothelial growth factor (VEGF) is a potent mitogen in endothelial cells, but little is known about its activity in other cell types. To clarify the role of VEGF in human dental pulp cells and pulp tissue, we investigated the effects of VEGF on the chemotaxis, proliferation, and differentiation of human dental pulp cells. VEGF induced a strong chemotactic response in human dental pulp cells in a dose-dependent manner. VEGF also marginally enhanced the proliferation of human dental pulp cells and induced an increase in alkaline phosphatase in human dental pulp cells. However, these effects of VEGF were not observed in reference to human skin fibroblasts. Analyses by the reverse-transcription/polymerase-chain-reaction method and flow cytometry showed that the mRNAs of two VEGF receptors, fins-like tyrosine kinase and kinase insert domain-containing receptor, were expressed in human dental pulp cells, whereas only fms-like tyrosine kinase mRNA was expressed in human skin fibroblasts. VEGF induced the activation of activator protein 1 (AP-1) and c-fos mRNA expression in human dental pulp cells. The AP-1 inhibitor curcumin strongly inhibited VEGF-induced alkaline phosphatase production in human dental pulp cells. In addition, VEGF antisense oligonucleotide suppressed the production of VEGF and alkaline phosphatase in human dental pulp cells. These results suggest that VEGF produced by human dental pulp cells acts directly upon human dental pulp cells in an autocrine manner, and may promote the chemotaxis, proliferation, and/or differentiation of human dental pulp cells via the utilization of kinase insert domain-containing receptor and in part through AP-1 by increasing c-fos.

Noninvasive approach for study of human reaction and transferring velocity of nervous system by using a new instrumentation devised for concurrent microscopic observation and analysis of sweat secretion on human body under 1G and microgravity

Human sweating is generally caused by thermal and mental stimuli. The former role is well known as a response for thermo regulation. The insensible perspiration may be generally controlled by the autonomic nervous system, and the responses due to mental and/or emotional stress by the sympathetic nervous system. As human sweating is directly concerned with some nervous systems, sweating may be a good indicator for the body reactions of feeling, surprise, emotional stress and etc. The measuring of sweat secretion and microscopic observation of active sweat glands can be presented the direct information of working of sympathetic nervous system and sudomotor. In the present report, we devised an instrumentation for the estimation of time lag of sweating [correction of seating] after physical stimuli. Variation of gravity during parabolic flights is a kind of physical stimulus. Iwase et al reported the changes of sympathetic outflow to muscle in humans during short periods of microgravity. We studied also the variation of number of active sweat glands under this condition for the evaluation of human sympathetic nervous system.

Mechanical tensile properties of the aortic wall in the premature rat exposed to the microgravity environment during space flight for 16 days

Under microgravity environment, blood shifts headward and thereafter decrease in volume to adapt to the environment, which could affect cardiovascular hemodynamics and their regulatory mechanisms. Baroreceptor sensitivity is known to be reduced in newborn animals and to gradually increase with development. The baroreceptor is a stretch receptor; therefore its function is closely related to the rheological properties and fine structure of the aortic wall in which the baroreceptor lies. The mechanical and histological properties could be altered under microgravity conditions in the process of development with change in circulatory function. In the present study, we investigated the mechanical tensile characteristics and histological structure of the aortic wall in the proximal thoracic aorta of premature rats bred in the microgravity environment of the space shuttle for 16 days.

Enzymic chemical reaction under microgravity environment in space

In recent years, some papers have reported synergism in the biological effects of space radiation and microgravity. However, there is no direct evidence for these phenomena. As one possible mechanism, we investigated whether DNA ligation in the final step of DSBs repair of DNA molecules induced by radiation is depressed by microgravity. Therefore, we have scheduled the space experiments of the effects of microgravity on repair activity of T4 DNA ligase for DSBs prepared with digestion of a restriction enzyme (Sma I) to plasmid DNA. As another possible mechanism, the high mutation frequency may be induced from abnormal base-incorporation during DNA replication under microgravity. Using the Taq polymerase and polymerase III, we have also scheduled whether mutation frequency is affected by microgravity during DNA replication for a damaged DNA base induced by an alkylating agent (N-methyl-N-nitrosourea, MNU).

Responses of motor and sensory neurons of rodents to spaceflight

Spinal motoneurons innervating skeletal muscles comprised predominantly of high oxidative fibers, i.e. slow oxidative and fast oxidative glycolytic, have higher oxidative enzyme activities than motoneurons innervating skeletal muscles comprised primarily of low oxidative fibers, i.e. fast glycolytic. These findings suggest that there is a close relationship between the oxidative phosphorylation capacity of a motoneuron and of the muscle fibers that it innervates. Since some skeletal muscles become faster and less oxidative after 4-14 days of spaceflight, it might be expected that oxidative enzyme activities in some motoneurons also may decrease after spaceflight. In addition, there is significant muscular atrophy after even short spaceflights and, therefore, it may be expected that some motoneurons associated with these muscles also would atrophy. In the present paper, we examine the issue of whether spaceflight induces changes in the oxidative enzyme activity and/or size of spinal motoneurons.

The effects of microgravity on ligase activity in the repair of DNA double-strand breaks

PURPOSE

In recent years, contradictory data have been reported about the effects of microgravity on radiation-induced biological responses in space experiments. The aim of the present study was to clarify whether enzymatic repair of DNA double-strand breaks is affected by microgravity using an in vitro enzymatic reaction system.

MATERIALS AND METHODS

The DNA repair activity of T4 DNA ligase (EC 6.5.1.1) was measured in vitro for a DNA substrate damaged by restriction enzyme digestion during a US Space Shuttle mission (Discovery; STS-91). After the flight, the amount of ligated DNA molecules was measured using an electrophoresis method.

RESULTS

Ligated products (closed circular DNA, open circular DNA and multimeric ligated products) were produced by T4 DNA ligase treatment of linear DNA containing double-strand breaks, and they increased with increasing T4 DNA ligase concentration (0-3 units per microg of plasmid DNA). Almost no difference in T4 DNA ligase activity was detected between the space experiments and the control ground experiments.

CONCLUSIONS

No significant effect of microgravity on ligation of damaged DNA was found during space flight. Therefore, other mechanisms must account for the synergism between radiation and microgravity, if it exists.

Comparison of the response of motoneurons innervating perineal and hind limb muscles to spaceflight and recovery

The succinate dehydrogenase (SDH) activities and cell body sizes of motoneurons in the dorsomedial (DM) region of the ventral horn at the lower portion of the L5 and the L6 segmental levels of the rat spinal cord were determined following 14 days of spaceflight and after 9 days of recovery on Earth and compared with those in the retrodorsolateral (RDL) region of the ventral horn at the same segmental levels. No changes in the mean SDH activity of motoneurons in the DM region were observed following spaceflight or after recovery. However, a decrease in the mean SDH activity of motoneurons with cell body sizes between 500 and 900 microm(2) in the RDL region was observed following spaceflight and after recovery. These data indicate that moderate-sized motoneurons in the RDL region, which are most likely associated with the hind limb musculature, were responsive to the microgravity environment. In contrast, the motoneurons in the DM region associated with the perineal muscles (associated with predominantly fast, low-oxidative muscles which are recruited for relatively brief periods at high activation levels and have no load-bearing function at 1G) were not affected by microgravity.

[Hematological abnormalities of primary Sjogren's syndrome]

Sjogren's syndrome (SS) is an autoimmune disease characterized by a chronic inflammatory response mainly localized to the lacrimal and salivary glands. However, it sometimes involves extraglandular organs culminating in systemic disorders. Hematological abnormalities are not uncommon, although they rarely have clinical significance. In this study we examined 99 patients with primary SS who visited our hospital during 1989 to 1999. Patient's mean age was 54.1 years and 95 out of 99 were female. Lymphopenia and leukopenia was noted in 35 patients (35.3%) and 26 patients (26.2%) respectively, and 7 patients (7.1%) had thrombocytopenia. 43 patients (43.4%) had either of these hematological abnormalities. Patients with lymphopenia showed significantly low frequency of arthralgia and anti-SS-A/B antibody was more common in this group. Only one patient in this group required prednisolone therapy because of polyarthritis and general fatigue while others needed no specific therapy. Patients with thrombocytopenia were significantly younger and a male/female ratio was higher than those without this abnormality. They had higher tendency to accompany with skin eruption, positive anti-SS-B antibody, anti-nuclear antibody and rheumatoid factor. Three out of 8 patients with thrombocytopenia were treated with prednisolone according to the protocol for idiopathic thrombocytopenic purpura. All of 3 patients had positive PA-IgG and normocellular bone marrow. Autoimmune mechanism such as polyclonal B cell activation may play a role in the pathogenesis of thrombocytopenia.

[A case of complete regression of liver metastases by treatment with Futraful supposition]

The patient was a 57-year-old man abnormalities indicated in examinations by X-ray and ultrasonography in February, 1991. X-ray and endoscopic examination revealed a Borrmann type 3 carcinoma in the posterior wall and lesser curvature of the upper body of the stomach. The liver was swollen to 3 fingerbreadths on the right mid-clavicular line. Multiple liver metastases were revealed by computed tomography (CT). Proximal gastrectomy was done. From March 24, 1991, a Futraful suppository (1,500 mg/day) was given daily. After 4 months, CT showed the reduction and partial disappearance of the low-density areas of the liver. After 2 years and 7 months, CT showed very small low-density areas, which completely disappeared by April, 1998. The patient has had a good quality of life. According to the General Rules for Gastric Cancer Study, the patient belongs to the class of complete response.

Accumulation of tumor suppressor p53 in rat muscle after a space flight

Tumor suppressor p53 functions as a cell cycle checkpoint under stressful conditions. Early studies have shown that genotoxic stress activates p53 pathway. Recently, many kinds of non-genotoxic stress such as heat shock, cold shock, and low pH also have been found to activate p53 pathway. The effects on living organism remains to be explored. Here, we show that an 18-day space flight induced a 3.6 fold accumulation of p53 in rat skeletal muscle. This results suggests that the p53 pathway plays a role in safeguarding genomic stability against the stressful space environments and supports our previous observation of p53 accumulation in rat skin after a space flight.

Application of real-time radiation dosimetry using a new silicon LET sensor

A new type of real-time radiation monitoring device, RRMD-III, consisting of three double-sided silicon strip detectors (DSSDs), has been developed and tested on-board the Space Shuttle mission STS-84. The test succeeded in measuring the linear energy transfer (LET) distribution over the range of 0.2 keV/micrometer to 600 keV/micrometer for 178 h. The Shuttle cruised at an altitude of 300 to 400 km and an inclination angle of 51.6 degrees for 221.3 h, which is equivalent to the International Space Station orbit. The LET distribution obtained for particles was investigated by separating it into galactic cosmic ray (GCR) particles and trapped particles in the South Atlantic Anomaly (SAA) region. The result shows that the contribution in dose-equivalent due to GCR particles is almost equal to that from trapped particles. The total absorbed dose rate during the mission was 0.611 mGy/day; the effective quality factor, 1.64; and the dose equivalent rate, 0.998 mSv/day. The average absorbed dose rates are 0.158 mGy/min for GCR particles and 3.67 mGy/min for trapped particles. The effective quality factors are 2.48 for GCR particles and 1.19 for trapped particles. The absorbed doses obtained by the RRMD-III and a conventional method using TLD (Mg(2)SiO(4)), which was placed around the RRMD-III were compared. It was found that the TLDs showed a lower efficiency, just 58% of absorbed dose registered by the RRMD-III.

Accumulation of a tumor suppressor p53 protein in rat muscle during a space flight

We previously reported that the space environment consisting of microgravity and space radiation induced an increased level of p53 protein, a tumor suppressor gene product, in rat skin. Here, we report the increase of p53 protein in the muscles of rats that traveled into space. Rats were divided into three groups. The first group remained on earth (VC), and did not show any change in p53 protein level. The second group made a 14-day flight into space on the Second Spacelab Life Science (SLS-2) Mission (F). The third group was experimentally subjected to the same kinds of stress as those in the second group without making a space flight (SC). F and SC rats were sacrificed on day zero (F-0, SC-0) and day nine (F-9, SC-9) after return from space. F-0 rats showed a 1.5-fold increase in p53 protein level compared with that of SC-0 rats, whereas, F-9 rats showed a 1.35-fold increase in p53 protein compared with that of SC-9 rats. These results suggest that the accumulation of cellular p53 protein induced by space environments occurs not only in rat skin cells, but also in rat muscle cells.

VFEU water quality control in STS-95 mission

In STS-95 Space Shuttle mission, an aquatic animal research facility, Vestibular Function Experiment Unit (VFEU), was flown to perform neurobiological experiment with marine fish, oyster toadfish. For this purpose, we have developed a sea water purification system using highly active nitrifying bacteria at low temperature. With this system, the water quality in the VFEU was maintained in sufficient condition to keep the toadfish in healthy state for 9 days of the mission. This report summarizes the efficiency of the filter system based on the results from pre-flight bacterial preparation, water analysis of samples taken during flight, and the post-flight analysis of the bacterial filter.

Expression of PDGF-beta receptor, EGF receptor, and receptor adaptor protein Shc in rat osteoblasts during spaceflight

A number of studies have indicated that microgravity induces osteopenia and modulates functions of mammalian cells. However, the molecular mechanisms underlying these effects of microgravity are still unknown. Rat osteoblasts were cultured for 4 and 5 days during Shuttle-Spacelab flight, and fixed by guanidine isothiocyanate solution on board after treatment with 1alpha, 25 (OH)2 vitamin D3. The mRNA levels for platelet-derived growth factor (PDGF)-beta receptor, epidermal growth factor (EGF) receptor, the growth factor receptor adaptor protein Shc, and c-fos were determined using the method of quantitative reverse transcription-polymerase chain reaction. The mRNA levels for EGF receptor were not altered by microgravity. However, the mRNA levels for PDGF-beta receptor, Shc, and c-fos were decreased to 62, 55 and 25% on the 4th day of flight, and 47, 40, and 43% on the 5th day, respectively, as compared to the corresponding ground controls. Expression of the growth factor receptor and the receptor adaptor protein was modulated in rat osteoblasts during spaceflight. Data suggest that signal transduction via growth factor receptors in rat osteoblasts is impaired by microgravity. Dysfunction of osteoblasts might be involved in spaceflight-induced osteopenia.

Application of nitrifying and denitrifying processes to waste management of aquatic life support in space

Since a biological filter with nitrifying bacteria was firstly applied to aquatic animal experiments in IML-2 mission, the reactor system has been further studied to combine both nitrifying and denitrifying reactions under aerobic environment allowing an efficient removal of inorganic nitrogen from animal wastes. The isolated denitrifying bacteria had an activity under aerobic condition with rice straw providing a metabolic carbon source for the reaction. The advantage of the aerobic biological filter having both nitrifying and denitrifying activities may allow to reduce the size of the life support system and also for its manageability. The paper reports characteristics of the biological filter systems used for the IML-2 mission and the improved combined filter system having both nitrifying and denitrifying activities, and discuss its application to space experiments.

Water quality management for low temperature marine fishes in space

Vestibular Function Experiment Unit (VFEU), one of the Spacelab facility flown in Neurolab mission (STS-90) in April, 1998, was to support neurophysiological research using a marine fish, Opsanus tau (oyster toadfish). The functions of the VFEU were primarily a quality management of environmental water during the mission at 14 degrees C and for acquiring physiological signals from implanted micro-electrodes in the otolith nerves as well as the spatial acceleration of the fish. A key element of the life support system was a balanced biological filter containing two types of nitrifying bacteria, Nitrosomonas for ammonia oxidization and Nitrobacter for nitrite oxidization. Although the 16 days mission was successful, two toadfishes died in late phase of the mission. Ammonium concentration in those two life support systems elevated to remarkably high level at the end of the mission whereas the other two indicated very low. This report summarizes the results of the water quality management of the VFEU during the Neurolab mission based on analysis of water samples taken during the flight and those taken prior and just after the flight.

Inflammatory cytokine production and specific antibody responses to lipopolysaccharide from endodontopathic black-pigmented bacteria in patients with multilesional periapical periodontitis

We examined the induction of the cytokines interleukin (IL)-1 beta, IL-6, and IL-8 by lipopolysaccharides (LPSs) from several species of possible endodontopathic black-pigmented bacteria. Studies were conducted in human whole blood cultures from six patients (two from each group) with differing numbers of periapical periodontitis lesions (i.e. patients with radiographically clear periapical lesions in 10 or more teeth (high-lesion group, n = 4), in one or two teeth (low-lesion group, n = 6), and six healthy volunteers with no periapical lesions (no lesion group)). LPS from Prevotella intermedia ATCC 25611, Porphyromonas gingivalis 381, and Prophyromonas endodontalis ATCC 27067 induced a higher IL-8 response in the subjects of the high-lesion group, compared with the subjects of the other two groups. To ascertain the degree of sensitization by test bacteria, we examined the reactivities of antibodies in serum and saliva from the subjects to different bacterial species. LPS from P. gingivalis reacted strongly with sera from the high-lesion group. Thus, LPS from black-pigmented bacteria may be involved in multilesional periapical periodontitis by inducing particular cytokines and/or humoral immune responses.

[A case of Sjögren's syndrome with retrobulbar optic neuritis and cutaneous vasculitis]

A 52-year-old woman, diagnosed as having Sjögren's syndrome by parotid sialography and lip biopsy after a two years history of recurrent purpuric rashes on her lower extremities, was admitted to our hospital because of visual disturbance in March 1998. On presentation at the department of ophthalmology, her right visual acuity was light perception, and laboratory findings showed elevated levels of antinuclear antibody and anti-Ro/SS-A and anti-La/SS-B antibodies. Cerebrospinal fluid analysis showed mild pleocytosis and elevated levels of total protein and Q-albumin. The IgG-index was within normal level and no oligoclonal band was found. Magnetic resonance imaging showed increased signal intensity at the right optic nerve. After treatment with m-PSL pulse therapy, her visual acuity recovered to 0.08. When prednisolone was gradually tapered to the dose of 30 mg per day, she was transferred to our department because of high grade fever and pancytopenia. She also suffered from palpable purpura in her extremities extending the trunk, whose pathological diagnosis was leukocytoclastic vasculitis. The immunohistochemical examination showed depositions of IgG and C1q. After two additional cycles of mPSL pulse therapies, clinical improvement was achieved. The titers of von Willebrand factor and thrombomodulin correlated with her clinical improvement. Patients with Sjögren's syndrome can develop extra-grandular complications, including neurologic and cutaneus diseases, it is important to understand the role of SS-A-B antibodies in the immunopathogenesis of Sjögren's syndrome.

Population dynamics of nitrifying bacteria in an aquatic ecosystem

In a space environment such as Space Shuttle or Space Station, animal experiments with aquatic species in a closed system pose a crucial problem in maintaining their water quality for a long term. In nature, ammonia as an animal wastes is converted by nitrifying bacteria to nitrite or nitrate compounds, which usually become nitrogen sources for plants. Thus an application of the biological reactor with such bacteria attached on some filters has been suggested and experimentally studied for efficient waste managements of ammonia. Although some successful results were reported (Kozu et al. 1995, Nagaoka et al. 1998, Nakamura et al. 1997, 1998) in the space applications, purely empirical approaches have so far been taken to develop a biological filter having a stable nitrifying activity. In this study, we constructed a mathematical model to deal with the dynamics of the ammonia nitrifying processes in a biological reactor. The model describes population dynamics of the ammonia-oxidizing bacteria and the nitrite-oxidizing bacteria cultivated on the same filter. We estimated parameters involved in the model using the experimental data. The result shows that these estimated parameters could be applied to general cases and that the two bacteria are in a symbiotic relationship; they can better perform when both coexist, as has been empirically recognized. Based on the model analysis, we discuss how to prepare a high performance biological filter.

Mn-porphyrin derivatives as an antioxidant for medical devices

It is well known that reactive oxygen species such as O*2- and H2O2 induce the biodegradation or cracking of medical devices in vivo or that they are released from inflammatory cells activated by devices to oxidize low-density lipoprotein. Therefore, the development of a novel antioxidant is required to eliminate the reactive oxygen species. In this paper, we report that Mn-porphyrin derivatives containing a macromolecular Mn-porphyrin are relatively stable compounds that can eliminate O*2- and/or H2O2. The dismutation of O*2- in the porphyrins was determined using a cytochrome c-assay by the xanthine/xanthine oxidase system and using the stopped-flow kinetic analysis technique. The possibility of porphyrins as scavengers of H2O2 was evaluated by in situ measurement with a Clark electrode. As a result, it has been found that Mn-porphyrin derivatives may be a vastly better scavenger of reactive oxygen species in vivo.

Sensitivity of shuttle vector plasmid pZ189 DNA to carbon ion beams

The sensitivity of shuttle vector plasmid pZ189 DNA to carbon ion beams was studied under dry conditions. This plasmid contains the supF gene that can be used in mutagenesis analysis. The survival curve of the plasmid had both a shoulder and exponential parts, and showed a D10 value of about 17 kGy for both Escherichia coli wild-type and DNA repair-deficient mutant (UV-sensitive) strains. Therefore, it was assumed that the excision repair system was not effective for repairing DNA lesions induced by irradiation with carbon ion beams.

Measurement of the directional distribution of incident particles in the Shuttle-Mir mission orbit

The measurement of the directional distribution of incident particles was made by using the Real time Radiation Monitoring Device (RRMD)-III placed inside the Space Shuttle STS-84 cruised at an altitude of 400 km and an inclination angle of 51.6 degrees, which are the same as the cruising orbit of the International Space Station (ISS). The directional distributions of incident particles were evaluated over the observed linear energy transfer (LET) range (1-100 keV/micrometers). The pitch angle distribution is also obtained using the geomagnetic model of IGRF-95. The result is roughly in good agreement with the distribution obtained by the VF1-MIN anisotropy model calculation within the present experimental errors, if the shielding distribution is assumed to be uniform.