Search

Acute cholecystitis can occur both inside and outside hospital settings. However, little is known about the clinical characteristics of hospital-acquired cholecystitis (HAC).To investigate the clinical characteristics of HAC in a tertiary academic hospital.This retrospective cohort study included hospitalized patients who were found to have gallstones without cholecystitis or cholangitis on admission between January 2018 and December 2021. Multi-variate logistic regression analysis was used to make comparisons between patients with and without HAC.In total, 890 patients met the inclusion criteria and were evaluated in this study. Forty-one patients (4.6%) developed HAC during the study period. Multi-variate logistic regression analysis showed that a history of cholecystitis or cholangitis, fasting for ≥1 day, and gallstones in the gallbladder neck were independently associated with increased risk of HAC. HAC occurred most frequently after several weeks of admission, and only four patients (9.8%) had bacteraemia.HAC was relatively common among hospitalized patients. Physicians should be aware of the possibility of HAC in symptomatic hospitalized patients with certain risk factors.

A high-efficiency continuous-wave laser-diode-pumped Yb:YAG laser has been realized at room temperature by high intensity pumping. The slope efficiency and optical-to-optical conversion efficiency were 77% and 72% for the absorbed pump power, respectively.

Summary form only given. In recent years, ytterbium-ion (Yb)-doped materials have been recognized having attractive potential for laserdiode (LD) pumped solid state lasers. One of the features of the Yb-doped materials is that it can incorporate very high concentrations of the Yb-ions with low concentration quenching. Highly laser ion-doped materials with short absorption length permit the use of thin gain media with high pump absorption efficiency. The thin media are useful for high efficiency oscillation by high intensity pumping, i.e., LDs with low beam quality can be used as pump sources with high mode-matching efficiency between the laser beam and the pump beam. For example at room temperature, the highest efficiencies, which close to the laser quantum limit of 91% and are the highest in the lasers to our knowledge, are obtained by continuous-wave (CW) microchip Yb:YAG lasers with a high ion concentration of 20 at.% by high intensity pumping [1]. Although the pump source was a Ti:sapphire laser, these results suggest that these efficiencies can be also obtained from LD pumped CW lasers with higher Yb-ion concentration materials, such as the stoichiometric Yb-doped materials, in which Yb-ion concentration is the highest in the Yb-doped materials.Until now, laser oscillations of only two stoichiometric Yb materials have been reported [2-5]. On YbAG, which is one of the stoichiometric material, it has several advantages. The thermal conductivity of the YbAG is two times larger than that of the other. The fractional thermal population at the lower laser level, which is corresponding to the reabsorption loss, of the YbAG is much smaller than that of the other because of higher energy separation of the lower laser level and the ground state. The YAG is optically isotropic, stable, and robust compared to the other Yb-doped host materials. In previous studies, we have achieved continuous-wave YbAG laser oscillations by using a microchip gain material to minimize the reabsorption loss by optimum thickness [4]. Although the pump source was a Ti:sapphire laser, the pump wavelength of 937 nm is suitable for LD pumping. Here, we present a continuos-wave microchip stoichiometric YbAG laser at room temperature by multimode LD pumping [5]. It is the first report for the continuous-wave oscillation of stoichiometric Yb laser by LD pumping, in our knowledge. We used a microchip YbAG laser gain material which was also used in the previous experiment [4]. The pump source was a low-brightness, multi-mode single emitter LD (OSRAM) with an emitter area of 1 μm × 200 μm. When the output power of the LD was 720 mW, the wavelength was 940 nm. The LD beam was focused in the laser crystal with a spot area of 30 μm × 150 μm. The pump absorption efficiency was 94%. In this experiment, the maximum pump intensity in the laser crystal was 19 kW/cm2 for the absorbed pump power. The peak wavelength of the lasing was 1079 nm which is a similar result in the previous experiment by Ti:sapphire laser pumping [4]. Figure 1 shows the output power of the YbAG laser by multi-mode LD pumping and Ti:sapphire laser pumping as a function of the incident pump power. The lasing threshold intensity for the absorbed pump power was around 4 kW/cm2. The maximum slope efficiency and the maximum optical-to-optical efficiency were 13% and 10%, respectively for the absorbed pump power. These efficiencies are low compared to those of the Ti:sapphire-laser pumped laser due to its low mode-matching efficiency andhigh lasing threshold. The optical-to-optical and slope efficiencies will be increased by multi path pumping schemes, which are usually used in thin-disk lasers, and precise compensation of thermo-optic effects.

Metallothionein-II (MT-II) and Cu, Zn-superoxide dismutase (Cu, Zn-SOD) interacted with mercury were detected by a new method utilizing isoelectric focusing-agarose or -polyacrylamide gel electrophoresis (IEF-AGE or IEF-PAGE) and nondestructive one-dimensional synchrotron radiation X-ray fluorescence (SR-XRF) analysis. When MT-II reacted with mercuric chloride, an obvious change of isoelectric point (pI = 3.7 - 4.7) for the intact form to alkaline pI (9.4) was observed. This marked migration of MT-II by the metal was blocked by addition of glutathione, suggesting that sulfhydryl functions participate in the pI variation. In contrast, interaction of Cu, Zn-SOD with mercury did not cause any changes of its pI although the metal bound tightly to Cu, Zn-SOD after electrophoresis; however, the enzyme activity was drastically suppressed. These observations indicate that combination of electrophoresis with SR-XRF analysis is an useful technique for detecting structural or functional alteration of protei...

The ability of amino acid side chains in the floor of the peptide binding groove of HLA-A2 to affect the presentation of a viral peptide to peptide-specific cytotoxic T lymphocytes (CTL) has been examined. HLA-A2 molecules with naturally occurring single amino acid substitutions of Phe to Tyr at position 9 (HLA-A2.4a, Tyr9) and Tyr to Cys at position 99 (HLA-A2.4b, Cys99) and a site directed mutant with a Val to Leu substitution at position 95 (Leu95) were examined for their ability to present the influenza virus matrix M1 55-73 peptide and several sequence variants of the M1 peptide to a panel of 36 M1 55-73-specific HLA-A2.1-restricted CTL lines. The Leu95 molecule demonstrated enhanced kinetics of M1 peptide presentation and the ability to be sensitized by lower concentrations of the M1 peptide than the A2.1 molecule. The Tyr9 and Cys99 molecules exposed to M1 peptide were not recognized by 33 out of 36 CTL lines. The Tyr9 and Cys99 HLA-A2 molecules could bind the M1 55-73 peptide because at least one CTL line was found that could recognize each of these molecules that were exposed to the M1 peptide. CTL recognition patterns of variant M1 peptides presented by the Tyr9 molecule demonstrated that the amino acid at position 9 can be a critical determinant of the conformation of the peptide-A2 complex, and indicated that a particular peptide can bind in the HLA-A2 peptide binding groove in more than one conformation.(ABSTRACT TRUNCATED AT 250 WORDS)

A combination method consisting of synchrotron radiation X-ray fluorescence imaging and histochemical staining was employed to examine the detailed distribution of metal elements and morphological changes in the kidney section of rats exposed simultaneously to mercurial. A single injection of mercuric chloride (5 mg kg (-1)) to rats resulted in significant urinary leakages of the biological markers for acute mercury intoxication. Under this condition (i) a striking damage of brush border, cell loss and a dominant accumulation of mercury in the proximal tubules, (ii) a good correlation between the tubular damage caused by mercury and localization of the toxic metal, and (iii) an obvious distribution difference between zinc and sulfur following mercury exposure, were successfully shown by the present procedure with a 20 micron thick specimen.

Alterations in renal superoxide dismutase (SOD) isozymes were examined in cancerous tissues of human renal cell carcinoma and the corresponding non-cancerous renal tissues. Cu,Zn-SOD activities in cancerous tissues were lower than those in normal tissues. Mn-SOD activities were varied in the cases examined, whereas no significant difference between cancerous and normal tissues was observed for Mn- or total-SOD activities. Immunoblot analysis showed that the loss in enzyme activity in cancerous tissue was greater than the decrease in protein content for either isozyme. The selective decrease in Cu,Zn-SOD activities in cancerous tissue observed in this study suggests that the cytoplasmic defense against free radical damage appears to be reduced in renal cell carcinoma.

Substantial part of patients who suffer from food allergy outgrow their allergic reaction. Moreover the mechanisms of this phenomenon are poorly understood. We studied cytokine mRNA expression in peripheral blood mononuclear cells (PBMC) from children with egg allergy, nine patients on active stage and eight were outgrown, and four healthy controls, by use of reverse transcription polymerase chain reaction. Following ovalbumin (OVA) stimulation in vitro, active patients demonstrated increasing IL-5 mRNA. In comparison, no increasing expression of IL-5 mRNA was observed in outgrown and healthy children. IL-4 and IFN-gamma mRNA expression has no tendency either to increase or to decrease in all three groups. There was no difference of proliferative responses for OVA among these groups suggesting that outgrown patients' PBMC did not fall into anergy or clonal deletion. These data suggested the change in balance of cytokine production of PBMC which were stimulated by allergen is a trigger for "outgrow" of food allergy.

To elucidate whether immunoglobulin (Ig) E or IgG are involved in the murine asthma model, we compared the pathogenic features of mice that were high IgG responders (C3H/He) with mice that were high IgE responders (BALB/c) after intratracheal instillation of diesel exhaust particles (DEP) and ovalbumin sensitization. Both mouse strains received DEP intratracheally once a week for 5 weeks. After the second injection of DEP, ovalbumin and aluminium hydroxide were injected intraperitoneally. After the last DEP administration, the mice were challenged by exposure to an aerosol of ovalbumin. DEP caused increased IgG1 production and airway hyperresponsiveness after ovalbumin sensitization in C3H/He mice, although IgE production did not change in either strain. Furthermore, in C3H/He mice, the number of eosinophils and goblet cells in the bronchial epithelium, and the expression of interleukin-5 and interleukin-2 were increased by DEP and ovalbumin treatments. In contrast, the pathogenic changes in BALB/c mice were weak, even though the same protocol was used. In conclusion, murine strain differences in response to air pollutants and allergens seem to be related to antigen-specific immunoglobulin G1 production and cytokine expression in the lungs.

By use of flow cytometry, we have investigated intracellular activated eosinophil cationic protein (ECP) in eosinophils and mitogen-induced cytokine production of T cells in peripheral blood from children with acute severe asthma. In addition, we measured ECP releasability (serum ECP/lysate ECP) as a maker of activated eosinophils. The monoclonal antibody EG2 (anti-activated ECP/EPX antibody) was used for measuring the amount of intracellular activated ECP. ECP releasability and mean fluorescence intensity (MFI) values of EG2-positive eosinophils increased at the time of asthmatic attack and reduced after treatment with improvement in peak expiratory flow. Furthermore, the frequency of T cells which produced IL-4, IL-5 and IFN-gamma stimulated with phorbol myristate acetate and ionomycin increased and reduced in parallel with MFI of EG2-positive cells. These observations suggest that flow cytometric analysis for intracellular ECP and mitogen-induced cytokine production reflects the activation of T cells in bronchial mucosa, and is useful for monitoring airway inflammation in bronchial asthma.

Stool smears of newborn infants were investigated sequentially from birth through 6 months of life in order to study relation between appearance of eosinophils in stool and feeding of babies. In babies born to non-atopic parents, eosinophils appeared in stool smear soon after start of feeding, but disappeared in a short time. Eosinophils were found irrespective of types of feeding, i.e., breast feeding, powdered milk or amino acid formula. There was tendency of sustained presence of eosinophils in stool smears in babies born to severe atopic parents. These results suggest that appearance in stool of eosinophils does not necessarily mean allergic reaction to ingested foods and need attention in diagnosing milk allergy. Mechanisms of appearance and function of eosinophils in stool in normal babies may differ from those in pathological situations and need further detailed investigation.

Nasal smear cytology was studied in pediatric patients with bronchial asthma with special reference with IgE RAST to house dust mite, Dermatophagoides pteronyssinus (Dp). Results obtained were as follows: (1) Numbers of eosinophils on the nasal smear correlated well with Dp RAST score, (2) mast cells were detected before Dp RAST becoming positive and appearance of eosinophils, (3) basophils appeared after detection of eosinophils and only in patients with nasal smear eosinophils. These results suggest that mast cells are the early marker for allergic inflammation and basophils and eosinophils appear in association with overt sensitization with house dust mite in house dust mite-sensitized asthmatic patients.

Gamma-Glutamyltransferase (GGT), formerly called gamma-glutamyltranspeptidase, is predominantly a membrane-bound enzyme. The estimation of enzyme activity in serum is useful in monitoring hepatobiliary complaints. The electrophoresis with surfactant (Triton X-100) developed by the authors demonstrates five distinct bands of enzyme activity in the serum from patients with hepatitis. These bands are called isoenzyme GGT1 to 5 from anode to cathode, respectively. Four isoenzymes GGT2 to 5, except GGT1 are demonstrated in normal adult serum. The affinity electrophoresis is more variable to identify the hepatoma associated isoenzyme, namely HA-GGT. Concanavalin A used in the method has no affinity with HA-GGT and this isoenzyme is separated from GGT2. The diagnostic sensitivity and specificity for the measurement of HA-GGT were 58% and 83%, respectively.

We studied the binding activities of IgE and IgG antibodies in patients with allergy to cow milk proteins, against different alpha-casein preparations: alpha-casein treated with urea, hydrochloric acid, sodium hydroxide, or sodium dodecyl sulfate (SDS); or heat-denatured alpha-casein. The binding activities of IgE and IgG antibodies to these denatured alpha-casein preparations were compared with those to native alpha-casein. The binding activities of IgE and IgG antibodies to these denatured alpha-casein preparations were similar to those to native alpha-casein although the binding activities of IgG antibodies to these denatured alpha-casein preparations were relatively heterogeneous compared with those of IgE antibodies. Since modifications of alpha-casein did not alter the ability of alpha-casein to react with these antibodies, IgE and IgG antibodies to alpha-casein in sera from patients with allergy preferentially bind to the antigenic determinants associated with primary protein structures.

Sjögren's syndrome (SS) is thought to be uncommon in children. We studied the clinical manifestations and laboratory findings of 12 pediatric patients with SS, all of children did not have sicca symptoms but have lymphocytic infiltration of salivary glands, abnormal sialograms or abnormal results of scintigraphy compatible with typical SS. Seven cases had primary SS and five were secondary SS and had other autoimmune disorders (three cases with systemic lupus erythematosus, one case with dermatomyositis, and the other with mixed connective tissue disease). All patients were female. The mean age at onset of symptoms, including other autoimmune manifestations, was 12.2 years (range 9-15 years). The initial symptoms were some systemic manifestations (fever, exanthema, arthralgia, etc.) and various autoimmune phenomena (butterfly rash, Raynaud's phenomenon, proteinuria, weakness of muscles, etc.). On the other hand, no patients complained sicca symptoms. Laboratory studies in our patients revealed elevated levels of IgG (92%), antinuclear antibody (92%), rheumatoid factor (58%), anti-SS-A antibody (75%). These findings were similar to those found in adult patients with sicca symptoms previously reported in literature. From these studies, we suggest that lip biopsy, sialography and/or salivary gland's scintigraphy should be carried out in patients who had abnormal laboratory findings as mentioned above, irrespective of absence of sicca symptoms, in order to diagnose SS at early period.

There is evidence from animal models that the iodine content of thyroglobulin (Tg) may influence its antigenicity in thyroid autoimmunity. To elucidate the effect of iodination of hormonogenic sites of human Tg (hTg) on its autoantigenicity, a synthetic peptide (TB: hTg 2546-2571), containing two hormonogenic tyrosine residues of hTg, and a chemically-iodinated peptide (TB-I) were prepared. We immunized C3H/He (H-2k) mice, a high responder strain to Tg, and BALB/c (H-2d), a low responder strain, with TB or TB-I plus lipopolysaccharide. Lymph node cells from the two strains immunized with TB or TB-I proliferated in response to both TB and TB-I. Anti-Tg autoantibodies were detected in both strains when immunized with TB-I, while immunization with TB failed to produce anti-Tg antibodies. Furthermore, one of the C3H/He mice immunized with TB-I developed diffuse thyroiditis, but BALB/c mice did not. These findings indicate that the iodination of the hormonogenic tyrosine residues of hTg, in other words, the synthesis of mono- and di-iodotyrosine (MIT and DIT) residues, is necessary for the production of anti-Tg autoantibodies in high and low responder mice and for the induction of autoimmune thyroiditis in high responder mice.

We studied the binding activities of IgE, IgG and IgA antibodies in patients with allergy to hen's egg white against two different ovalbumin (OVA) preparations, which were physically or chemically denatured OVA and enzyme-digested OVA fragments. The binding activities of IgE antibodies to these OVA preparations with those of IgG or IgA antibodies were compared. It was found that the binding activities of IgE antibodies to denatured OVA by treatment with dithiothreitol, urea or hydrochloric acid were similar to those of IgG or IgA antibodies. In contrast, the binding activities of IgE antibodies to heat-denatured OVA or by treatment with sodium hydroxide at pH 11.0 were different from those of IgG or IgA antibodies to these denatured OVA. Furthermore, we found that the binding activities of anti-OVA antibodies in sera from patients with allergy to hen's egg white against fragmented OVA were different between IgE antibodies and IgG or IgA antibodies. Thus, it can be concluded that IgE antibodies to OVA in sera from patients with allergy to egg white differ from IgG or IgA antibodies in respect to binding activities against different preparations of denatured or fragmented OVA, probably due to differences in fine specificities of these antibodies against OVA.

We established a thyroglobulin (Tg)-specific, thyroiditis-inducing T-cell clone, B12G, from B6C3F1 mice by the immunization of mouse Tg with lipopolysaccharide (LPS) from Klebsiella strain LEN (O3:K1). B12G was Thy-1.2+, CD3+, CD4+, CD18+, and CD8-, and could transfer thyroiditis to recipient mice after in vitro stimulation with mouse or bovine Tg. Histological examination showed severe thyroiditis with predominant infiltrations of polymorphonuclear cells; few mononuclear cells were observed. B12G proliferated in response to bovine, mouse, porcine, and rat Tg in the presence of irradiated spleen cells, but did not respond to chicken or human Tg. H-2b, a low-responder haplotype of experimental autoimmune thyroiditis, governed the response of the clone to Tg. B12G produced interleukin-4 (IL-4) and IL-6, but not IL-2 or interferon-gamma (IFN-gamma), on stimulation with mouse Tg. These findings were different from characteristics of previously reported Tg-specific T-cell clones from high-responder mice in terms of epitope specificity and cytokine production pattern, raising the possibility that the specificities and functions of T cells involved in the development of autoimmune thyroiditis in low-responder mice differ from those in high responders.

Ten ovalbumin (OVA)-specific T cell lines (TCLs) were established from peripheral blood mononuclear cells of 6 patients with hen egg allergy, and the antigen recognition of these TCLs was characterized. Two OVA epitopes were determined by use of 3 synthetic OVA peptides which have been known as murine T cell epitopes. Blocking of antigen-specific T cell proliferation by anti-HLA class II monoclonal antibodies suggest that all 3 HLA class II molecules could act as restriction elements for T cell recognition of OVA. This is the first demonstration of OVA epitopes recognized by T cells in patients with hen egg allergy, as far as we know.

A six-month old baby, who had been fed for 2 months with casein hydrolysate formula (MA-1) for treatment of milk allergy, developed diarrhea. The baby's RAST score for milk was negative. IgE antibodies to MA-1 but not to MA-1 depleted of lipid (fat-free MA-1), were demonstrated by enzyme-linked immunosorbent assay (ELISA). It was confirmed by the appearance of numerous mast cells and eosinophils in a rectal smear taken after challenge with MA-1 (but not detected after challenge with fat-free MA-1) that some component in the lipid of MA-1 must be an allergen in this patient.

The anaerobic threshold is useful for estimating the intensity of physical exercise. It is shown as either an increase in blood concentrations of lactate or a disproportionate increase in ventilation. We developed a lactate analyzer based on an electroenzymatic method with a continuous blood sampling system through a double-lumen catheter. Ascorbic acid, bilirubin, hemoglobin, creatinine, uric acid, and glucose did not interfere the results. The lactate concentrations in blood samples from healthy subjects during physical exercise correlated well (r = 0.993) with results measured by the conventional enzymatic method. We measured the concentrations of blood lactate with a use of this lactate analyzer to see the anaerobic threshold in nine healthy volunteers during exercise on a treadmill with an increasing workload. The point at which lactate concentrations started to increase was detected easily. The anaerobic threshold identified as a disproportionate increase in ventilation was seen at almost the same time. We conclude that the lactate analyzer, with a continuous blood sampling system, can measure precisely concentrations of lactate in blood and can detect the anaerobic threshold during physical exercise.

We performed rectal and/or oral challenge tests on 8 patients with suspected but unproven diagnosis of food allergy based on detailed medical history and findings from radioallergosorbent tests (RAST). The cells appearing in the rectal mucosal smear serially for 48 hours after allergen challenge were examined. The following results were obtained: 1) Significant numbers of not only eosinophils but also mast cells appeared in the rectal smears after challenges with suspected-food allergens, but not with unrelated foods. This confirmed the antigen-specificity of the method. 2) In some cases, the appearance of mast cells and eosinophils was bimodal, suggesting the existence of a later allergic response in addition to an immediate-type reaction. 3) The food-specific appearance of mast cells and eosinophils was observed in association with clinical symptoms after challenge, even in patients whose IgE antibodies to the allergen were negative or commercially unavailable. In conclusion, we propose that rectal mucosal cytology in conjunction with rectal and/or oral challenge tests is a reliable and objective method to diagnose unproven or suspected food allergy.

Thyroglobulin (Tg) is one of the major thyroid autoantigens involved in autoimmune thyroiditis. The immune response of mice to Tg is genetically controlled by H-2-linked genes. To elucidate the regulation mechanism of autoimmune response to Tg in low responder mice, we studied the proliferative response of lymph node cells (LNC) to mouse Tg (MTg) and enzyme-digested MTg fragments. MTg was treated with Staphylococcus aureus V8 protease followed by separation of the fragments into 6 fractions (Fr1-Fr6: 264,000-17,000) by high performance liquid chromatography (HPLC), LNC from MTg immunized CBA/N (H-2k) mice, a high responder strain, proliferated in response to MTg and all fractions (Fr1-Fr6) of MTg fragments in vitro. In contrast, LNC from MTg immunized BALB/c (H-2d) and B10 (H-2b) mice, low responder strains, did not respond to native Tg but responded well to some smaller Tg fractions (Fr3, 4, 5). In addition, when BALB/c mice were immunized with MTg Fr4 with a molecular weight of 63,000, LNC from BALB/c mice proliferated in response to MTg as well as MTg Fr4. These findings suggest that T cells which are capable of responding to Tg do exist even in low responder mice and that the activation of these autoreactive T cells is suppressed by a regulatory cell subpopulation in low responder mice.

To clarify the effect of toluene on behavior, and to evaluate urinary orthocresol excretion as an indicator of toluene exposure and locomotor activity, we have investigated the urinary orthocresol excretion and levels of locomotor activity in rats exposed to 0-3000 ppm of toluene intermittently for 2 hours. The levels of locomotor activity were measured by a laboratory animal activity measuring apparatus (ANIMEX-III). Exposure of adult male rats to more than 1000 ppm (v/v) of toluene caused an elevation of the urinary orthocresol excretion and a good correlation was noted between the amount of toluene in the air and the urinary orthocresol excretion. Exposure to over 2000 ppm of toluene suppressed the level of locomotor activity, and there was a good correlation between the level of locomotor activity and the urinary orthocresol excretion. Further, rats exposed to 3000 ppm toluene showed elevated levels of locomotor activity during a 10-hour period after exposure. These patterns of urinary orthocresol excretion and the levels of locomotor activity remained unchanged even when rats were exposed to 3000 ppm of toluene intermittently over a 4-day period.

Systemic lupus erythematosus (SLE) is a disease caused by immune complexes (IC) and is sometimes accompanied by cutaneous vasculitis at the time of onset or in case of relapse. Usually, however, this manifestation does not newly develop after the beginning of steroid treatment. Here we report on a 16-year-old boy with SLE who developed cutaneous vasculitis 10 days after starting systemic prednisolone treatment despite improvements in clinical and laboratory parameters. We examined the molecular sizes of circulating immune complexes (CIC) through the course of the disease. At the time of admission the CIC were 7S to 19S in size. When the patient developed cutaneous vasculitis, the large component of CIC decreased and the 7S CIC became the major component. Although definitive conclusions cannot be drawn, it is suggested that the shift to the smaller size of the CIC is related to the development of cutaneous vasculitis.

A major focus of current immunological research is to determine the structure-function relationships of class I MHC molecules. The determination of the three-dimensional structure of HLA-A2.1 by Bjorkman et al. (1987a, 1987b) has significantly advanced our ability to achieve this goal. The α3 domain, which composes the membrane proximal region of the molecule, has a structure similar to that of the constant region of immunoglobulin, and primarily associates with β2- microglobulin. The membrane distal region consists of the α1 and α2 domains which interact to form a β-sheet platform, on top of which reside two antiparallel α-helices that are separated by a long groove. It was hypothesized that this groove acts as the binding site for peptides that are recognized by the TCR in association with class I molecules and in fact, an unidentified peptide(s) was associated with this groove in the crystal structure. An analysis of the crystallographic structure of HLA-A2.1 reveals that nearly all of the side chains of the polymorphic residues are oriented such that they point into the groove of the molecule and thus could be important in mediating contact with peptide, or they point upward from the α-helices and may thus be important in interacting with the TCR (Parham et al. 1988).

A cross sectional study of risk factors in respiratory diseases was carried out in August 1986, in Beijing, China. Inhabitants greater than or equal to 40 years old were selected at random from a rural area, a residential area and an industrial area, using a two stage sampling method. The analysis presented here is based on the sample population of adults who (1) were prepared to be interviewed, using the British Medical Research Council's questionnaire translated into Chinese (n = 3423) and (2) had lung function measurements at the same time (n = 3373). Obstructive lung disease was defined as forced expiratory volume in 1s (FEV1) less than 68% of forced vital capacity (FVC). Seven variables were considered as potential risk factors or confounding factors: area of residence, sex, age, cigarette smoking, history of respiratory disease, socio-economic status and familial component. A modified binary variable regression method developed by Feldstein was used for the adjustment of rate ratios. The adjusted prevalence of obstructive lung disease was highest in the rural area and lowest in the residential area(s). An increase in age, cigarette smoking, low socio-economic status and positive history of respiratory diseases were associated with significantly higher rates of impaired pulmonary function. The other measured factors did not appear to be related to impaired pulmonary function.

Crystallographic studies of the HLA-A2 molecule have led to the assignment of a putative peptide binding site that consists of a groove with a beta-pleated sheet floor bordered by two alpha-helices. A CTL-defined variant of HLA-A2, termed HLA-A2.2F, differs from the common A2.1 molecule by three amino acids: a Leu to Trp substitution at position 156 in the alpha-2 helix, a Val to Leu substitution at position 95 in the beta-sheet floor of the groove, and a Gln to Arg substitution at position 43 in a loop outside of the groove. Another HLA-A2 variant, termed CLA, has a single Phe to Tyr substitution at position 9 that is sterically located adjacent to position 95 in the beta-sheet floor of the groove. We have determined which of the amino acid substitutions at positions 9, 43, 95, or 156 could individually affect recognition by panels of A2.1 allospecific and A2.1-restricted influenza viral matrix peptide-specific CTL lines, using a panel of site-directed mutants and CLA. Recognition by allospecific CTL lines was generally unaffected by any one of the amino acid substitutions, but was eliminated by the double substitution at positions 95 and 156. Allorecognition by some CTL lines was eliminated by a single substitution at position 9 or 95. In contrast, recognition by A2.1-restricted matrix peptide specific CTL was totally eliminated by a single substitution at position 9 or 156. The substitution at position 43 in a loop away from the peptide binding groove had no effect on allorecognition or matrix peptide recognition. These results indicate that amino acid residues in the floor or alpha-2 helical wall of the peptide binding groove of the HLA-A2 molecule can differentially affect allorecognition and viral peptide recognition.

The HLA-A2 molecule contains a putative peptide binding site that is bounded by two alpha-helices and a beta-pleated sheet floor. Previous studies have demonstrated that the influenza virus matrix peptide M1 55-73 can sensitize target cells for lysis by HLA-A2.1-restricted virus-immune CTL and can induce CTL that can lyse virus-infected target cells. To assess the specificity of peptide binding by the HLA-A2.1 molecule, we examined the ability of seven variant M1 peptides to be recognized by a panel of M1 55-73 peptide-specific HLA-A2.1-restricted CTL lines. The results demonstrate that five out of the seven variant M1 55-73 peptides could be recognized by A2.1-restricted M1 55-73 peptide-specific CTL lines. The two variant peptides that were not recognized by any CTL could bind to HLA-A2.1 as indicated by their ability to compete for presentation of the M1 55-73 peptide. In addition, 5 of a panel of 24 unrelated peptides tested could also compete for M1 55-73 presentation by HLA-A2.1. One peptide derived from the sequence of a rotavirus protein could sensitize HLA-A2.1+ targets for lysis by M1 55-73 peptide-specific CTL. We conclude from these studies that: 1) the HLA-A2.1 molecule can bind a broad spectrum of peptides; 2) T cells selected for the ability to recognize one peptide plus a class I molecule can actually recognize an unrelated peptide presented by that same class I molecule; and 3) a stretch of three adjacent hydrophobic amino acids may be an important common feature of peptides that can bind to HLA-A2.1.

Previous studies have demonstrated that certain amino acid substitutions in the alpha two domain at positions 152 and 156 in the alpha two helix of the HLA-A2 molecule can affect presentation of the influenza virus matrix peptide M1 55-73 without abolishing binding of the M1 peptide. HLA-A2.1-restricted M1 55-73 peptide-specific CTL lines obtained from almost all HLA-A2.1+ individuals fail to recognize the M1 peptide presented by site-directed mutants of HLA-A2 that have either a Val----Ala or Val----Gln substitution at position 152 or a Leu----Trp substitution at position 156. Only one HLA-A2+ individual (donor Q66, HLA-A2,-B53,-B63) has been found who is able to generate a unique repertoire of HLA-A2-restricted M1 peptide-specific CTL that can recognize peptide presented by HLA-A2 mutants with either an Ala or Gln substitution at position 152 or a Trp substitution at position 156. These Q66 M1 peptide-specific CTL could be selected by stimulation with M1 peptide-pulsed transfectants that express the mutant HLA-A2 gene with the Trp substitution at 156. To determine if the presence of the unique CTL repertoire could be attributed to a variant HLA-A2 molecule in Q66, sequences were determined from polymerase chain reaction-amplified segments of the HLA-A2 RNA. Two different HLA-A2 genes were found expressed in Q66 cells: one is identical to HLA-A2.1 and the other is identical to HLA-A2.2F (Gln----Arg at position 43, Val----Leu at position 95, and Leu----Trp at position 156). These results demonstrate that a different CTL repertoire specific for HLA-A2 plus the M1 55-73 peptide is generated in an individual that expresses both HLA-A2.1 and HLA-A2.2F compared to individuals who express HLA-A2.1 alone, and that the unique repertoire can be selected by the presence of an HLA-A2 molecule with a single amino acid substitution at position 156.

Previous studies have suggested that MHC class I molecules bind and present peptides to CTL in a manner that is analogous to the presentation of peptides by class II molecules to Th. Crystallographic studies of HLA-A2 have led to the assignment of a putative peptide binding site that is bordered by two alpha helices consisting of residues 50-84 and 138-180. In this study, we have investigated whether residues in the alpha 2 helix are involved in the binding and/or presentation of a peptide to CTL. We have generated CTL to type A influenza virus by stimulation of human PBL with a synthetic peptide from the influenza A virus matrix protein (M1 residues 57-68) in the presence of rIL-2. Such HLA-A2.1-restricted influenza virus-immune CTL do not recognize infected HLA-A2.3+ targets. A2.1 and A2.3 differ by three amino acids in the alpha 2 domain: Ala vs. Thr at position 149, Val vs. Glu at position 152, and Leu vs. Trp at position 156. Site-directed mutants of the A2.1 gene that encode A2 molecules that resemble A2.3 at positions 149, 152, and 156 have been constructed, transfected into human cells, and assayed for their ability to present the M1 peptide. The results demonstrate that most, but not all, A2.1-restricted M1-peptide-specific CTL fail to recognize M1 peptide-exposed transfectants with certain single amino acid substitutions at positions 152 and 156. In contrast, M1 peptide-exposed transfectants that express A2 molecules with an Ala----Thr substitution at position 149 were recognized by all CTL tested, but they exhibited an apparent difference in the kinetics of peptide binding. These results indicate that amino acid substitutions at positions 152 and 156 of the putative peptide binding site of the A2 molecule can affect presentation without eliminating binding, and indicate that the failure to recognize complexes between the peptide and the mutant A2 molecules is due to different TCR specificities and not to the failure to bind the peptide.

2,15 - Dimethoxycarbonyl - [15]annulenone 4,7:10,13 - dioxide (14) has been prepared by the condensation of cis -α,β -bis(5 - formyl - 2 - furyl)ethy]ene (13) with dimethyl acetonedicarboxylate. Treatment of 14 with conc H2SO4 led to 4,7:10,13-dioxido[15]annulenone 2,15-dicarboxylic acid anhydride (17), which was subsequently converted to the corresponding dicarboxylic acid (18) by dilute KOH. Decarboxylation of 18 gave rise to two isomeric [15]annulenone 4,7:10,13 - dioxides, i.e., the tri-cis isomer (7) and the mono - trans - di - cis isomer (8). Regarding to the ring current effects, the proton chemical shifts of these [15]annulenones were compared with those of a reference model, 4,7:10,13 - dioxido - cyclopentadecaheptaene (2.4.6.8.10.12.14) (3). Both of the parent [15]annulenones (7 and 8) have been interpreted as nondiatropic, while the anhydride (17) has been shown to be diatropic, sustaining an induced diamagnetic ring current. The enforced planarity and symmetrical geometry of the anhydride have been discussed. As expected, when 7, 8, 14, 17 and 18 were dissolved in CF3COOH or conc H2SO4, completely delocalized [15]annulenium cations were produced, all of which proved to be diatropic. Three possible geometrical isomers of these 14π cations were established experimentally.

The titled annulenone 6 , the first benz-annelated 11-membered fully conjugated ketone, has been prepared by the aldol type condensation of 3-benzoxepin-2,4-dialdehyde 3 and dimethyl acetone-dicarboxylate. Some evidence for the nonaromatic character of 6 could be obtained from the NMR and IR spectra as well as protonation behaviour of 6 . The NMR spectrum of 6 in conc H 2 SO 4 confirmed the presence of an aromatic 1-hydroxy-6,7-benzo-4,9-oxido[11]annulenyl cation 7 . 6,7-Benzo-4,9-oxido-1-hydroxy-1-homo[10]annulene 11 was prepared by the NaBH 4 reduction of 6 . The treatment of 11 with CF 3 COOH regenerated another completely delocalized [11]annulenyl cation 12 . The pk R + of 12 was obtained as −4·1, spectrophotometrically. The electronic spectra of these novel cations ( 7 and 12 ) were found to be similar to those of 4,5-(2′,3′-naphtho)tropylium cations ( 13a and 13b ), respectively.

Using thyroid peroxidase (TPO), which was purified from the thyroid of patients with Graves' disease, we attempted to determine whether sera from patients with chronic thyroiditis contained antibodies to the enzyme. When the binding was tested by ELISA, sera from patients with chronic thyroiditis revealed high binding activities to TPO. When TPO was incubated with IgG from sera followed by treatment with protein A-Sepharose and centrifugation, the remaining TPO activities in the supernatant fraction were lower in most of the patients, as compared to normal controls. Moreover, IgG purified by DEAE-cellulose chromatography from sera in patients interfered with the TPO activities. Titres of anti-TPO antibodies correlated well with those of anti-microsome antibodies. These results indicate the presence of autoantibodies to TPO in sera of most patients with chronic thyroiditis and that TPO may be one component of microsome antigen complexes recognized by the autoantibodies. Studies on the inhibition of TPO by IgG isolated from sera of patients using guaiacol and iodide assays revealed that at least three epitopes of TPO molecule were recognized by autoantibodies and that the antigenic determinants on TPO molecule recognized by autoantibodies could be heterogeneous in patients.

A diabetes-inducible form of cytochrome P-450, termed P-450DM, was purified to electrophoretical homogeneity (MW 51,000) by high-performance liquid chromatography from liver microsomes of diabetic rats induced with streptozotocin. The CO-reduced absorption maximum of P-450DM was at 452 nm and the oxidized heme iron appeared to be predominately in the high-spin state as deduced from the Soret maximum at 395 nm. P-450DM was active in aniline hydroxylation and N-nitrosodimethylamine demethylation. The dealkylation activity toward 7-ethoxycoumarin by P-450DM was much enhanced by the addition of cytochrome b5.