Biomedical subjects

J L Lan

Publications and source records attributed to J L Lan.

At least 37 records · Page 2Linked to original sources

PubMed1998

Gallium-67 scintigraphy to predict response to therapy in active lupus nephritis.

UNLABELLED: Gallium-67-citrate has been used to detect inflammation for decades, and 67Ga uptake usually indicates an active, potentially curable lesion. In this study, we determined the value of 67Ga renal scintigraphy for predicting response to therapy in patients with lupus nephritis. METHODS: Forty-seven patients with lupus nephritis and abnormal serum creatinine or elevated 24-hr urine protein were enrolled. Delayed 48-hr 67Ga imaging was performed to evaluate 67Ga uptake by the kidneys. Serum creatinine and 24-hr urine protein values were obtained at the beginning of this study and after 1 yr of treatment. Serum creatinine was considered abnormal at levels greater than or equal to 1.4 mg/dl and 24-hr urine protein at levels greater than or equal to 1.0 g/day. When the value of serum creatinine or 24-hr urine protein obtained 1 yr after treatment was in the normal range or was 50% of the initial abnormal value, the patient was considered to have good response to treatment. RESULTS: Gallium-67 renal scan showed good correlation with the response to therapy in patients with lupus nephritis. In the negative 67Ga scan group, no significant changes in laboratory data were noted between onset of this study and after 1 yr of therapy. In the positive 67Ga scan group, there were significant decreases in serum creatinine and 24-hr urine protein levels 1 yr after treatment, especially in 24-hr urine protein, with p values of 0.019 and 0.0007 respectively, by Student's t-test for dependent samples. Moreover, 11.5% of patients with a negative 67Ga scan had a good response to treatment, whereas 71.4% of patients with a positive 67Ga scan had a good response to treatment. CONCLUSION: We suggest that 67Ga renal scan is a valuable predictor of response to therapy in patients with lupus nephritis.

Adult↗

PubMed1997

Renal vein thrombosis in Chinese patients with systemic lupus erythematosus.

OBJECTIVES: To evaluate the risk factors associated with renal vein thrombosis (RVT) in Chinese patients with systemic lupus erythematosus (SLE). METHODS: Data on clinical symptoms, renal biopsy, antiphospholipid antibody syndrome profile, and serological examinations of lupus features were examined retrospectively in six patients with RVT confirmed by angiography from a total of 625 patients with SLE over a 14 year period (1982-1996). RESULTS: The lupus patients with RVT did not have acute symptoms of severe flank pain, haematuria, and oligouria. In contrast, most patients were suspected to have RVT because of peripheral oedema and worsening proteinuria. Roentgenological examinations (including renal sonography, renal computer tomography, or renal Doppler, or all three) were positive only in some patients. Positive antiphospholipid antibody profiles were found in four of six lupus patients. By renal biopsy, only two samples were confirmed as World Health Organisation (WHO) class V lupus membranous glomerulonephritis. The others were class IV in three patients, and class III in the remaining one. No RVT was found in lupus patients without nephrotic syndrome. Peripheral thrombophlebitis was, however, noted in only one patient. CONCLUSION: Nephrotic syndrome could be a distinct risk factor in the development of RVT in Chinese SLE patients, in contrast with that reported in white populations in whom the peripheral thrombotic events were recognised as a determining factor.

Adult↗

PubMed1997

Technetium-99m-HMPAO brain SPECT in systemic lupus erythematosus with CNS involvement.

UNLABELLED: Functional brain SPECT is playing an increasingly important role in evaluating CNS conditions in patients with systemic lupus erythematosus (SLE). However, SPECT findings varied in different studies because of their small population. Furthermore, earlier researchers, being restricted by the resolution of the camera, might not have been able to evaluate deep-seated nuclei such as the basal ganglia and thalamus. In this study, we describe the different patterns of SPECT findings in SLE patients with CNS involvement. METHODS: Seventy-two SLE patients (aged 14-67 yr; mean 33.2 yr) were divided into three groups: Group 1 with definite neuro-psychiatric disorder (including stroke, seizures and psychosis); Group 2 with minor neuropsychiatric disorders (headache, dizziness and recent memory impairment); and Group 3 without any neuropsychiatric symptoms or signs. Ninety minutes after injection of 1110 MBq 99mTc-HMPAO, brain SPECT was performed using a dual-head camera and fan-beam collimator. In addition, MRI and an electroencephalography (EEG) were also performed. RESULTS: SPECT findings were normal in 87% of the Group 3 patients and abnormal in all Group 1 patients; 84.6% of the Group 2 patients had abnormal SPECT findings. The parietal, frontal and temporal lobes were the most common areas of CNS involvement. Parietal lobes were involved in 95.6% of Group 1 patients and 80.7% in Group 2 patients. Frontal lobes were involved in 56.5% of Group 1 patients and 65.3% of Group 2 patients. Temporal lobes were involved in 56.5% of Group 1 patients and 46.1% of Group 2 patients. The basal ganglion was involved in about 30% of Group 1 patients and 11.5% of Group 2 patients, while the thalamus and cerebellum were less involved in neuropsychiatric SLE. MR images showed less sensitivity in the detection of CNS involvement than the SPECT and were normal in 27.3% of patients with definite neuropsychiatric disorders. The EEG and anticardiolipin antibody did not correlate well to the clinical diagnosis. CONCLUSION: HMPAO brain SPECT had the best correlation with the clinical diagnosis and may provide additional and objective information on SLE patients with potential CNS involvement.

Adolescent↗

PubMed1997

Two color analysis of HLA-B27 antigen by flow cytometer--a comparative study by conventional microlymphocytotoxicity, DNA genotyping polymerase chain reaction and flow cytometric measurement.

For evaluation of specificity and sensitivity of flowcytometric determination of HLA-B27 antigen, we determined the HLA-B27 on lymphocytes using HLA-B27 monoclonal antibody by flow cytometer. Data were compared to those by conventional Terasaki microlymphocytoxicity test and DNA genotyping Polymerase Chain Reaction (PCR) method. One hundred and ninety four patients with various forms of arthritis were included in this study. Forty one of them were HLA-B27 positive, confirmed by three methods concomitantly with complete accordance. None of serological B27 negative, B7 CREG positive cells were found to be flowcytometric fluorescence positive. Furthermore, there was no significant difference of B27 intensity between different B27 DNA subtypes, nor was there any difference between primary ankylosing spondylitis (AS) and other secondary spondylitis patients as measured by mean channel of fluorescence. It is suggested that flowcytometric measurement of HLA-B27 antigen is a rapid and reliable method for HLA-B27 determination.

Antibodies, Monoclonal↗

PubMed1996

American cockroach Cr-PI allergen induces lymphocyte proliferation and cytokine production in atopic patients.

BACKGROUND: Previous studies have shown cockroach-induced antigen-specific IgE-mediated asthma. In cockroach-infested areas, more then 50% of asthmatic subjects may have positive skin reactions to this allergen. Partial purified Cr-PI allergen from American cockroaches contains allergens with molecular weights of 72 and 78 kDa; however, little is known about its effect on the lymphocyte proliferation and cytokine production. OBJECTIVE: IgE synthesis is known to be regulated by interleukin-4 (IL-4) and interferon gamma (IFN gamma). Therefore, we studied Cr-PI allergen-induced cytokine production in atopic patients and healthy normal controls to understand each factors' role in the disease. METHODS: Peripheral blood mononuclear cells (PBMC) from cockroach skin-sensitive patients and controls were stimulated with mitogen and Cr-PI for proliferative response and cytokine production. Cr-PI antigen-specific T-cell cultures of atopic patients and healthy normal controls were used to test Cr-PI-induced proliferation and cytokine mRNA expression. RESULTS: PMBC of atopic subjects showed a significantly (P < 0.01) higher stimulation index for Cr-PI induced proliferation (SI = 11.8 +/- 3.7) when compared with that of non-atopic subjects (SI = 4.1 +/- 0.8) and cord bloods (SI = 2.1 +/- 0.4). Cr-PI-induced IL-4 was observed only in the PBMC of atopic patients, whereas Cr-PI-induced IFN gamma was detected in both atopic patients and normal controls. Likewise, Cr-PI-induced IL-4 mRNA expression in T-cell cultures was detected in all atopics but only one of nine controls. CONCLUSION: IL-4 mRNA expression and IL-4 production in PBMC and T-cell cultures of atopic patients showed good correlation with clinical symptoms, skin-reactivity, specific IgE and proliferative response to Cr-PI. These results suggests that cockroach allergen may be a hidden cause of asthma and other atopic diseases.

Adult↗

PubMed1995

Role of tumor necrosis factor-alpha in the regulation of activated synovial T cell growth: down-regulation of synovial T cells in rheumatoid arthritis patients.

To characterize the role of tumor necrosis factor (TNF)-alpha in regulating synovial T cell growth, cell cycle progression associated with TNF-alpha in mitogen-activated synovial T cells of patients with rheumatoid arthritis (RA) were analyzed. After mitogen stimulation, the majority of synovial T cells in RA patients accumulated in S-phase. Anti-human TNF-alpha monoclonal antibody and soluble recombinant human TNF receptor (rhTNFR) can block S-phase accumulation. Furthermore, synovial fluid (SF) from RA patients was able to inhibit the proliferation of these S-phase-accumulated T cells. These data indicate that TNF-alpha could regulate activated synovial T cell growth by driving them into S-phase. Combined with the activities of other components of SF, TNF-alpha seems to play an important role in down-regulating activated synovial T cells in RA patients. In addition, the elevated level of soluble TNFR in the SFof disease-active RA patients is believed to be associated with the promotion of synovial T cell responses.

Arthritis, Rheumatoid↗

PubMed1995

Effects of corticosteroid inhalation therapy on the deposition pattern of Tc-99m human serum albumin radioaerosols in asthma.

This study evaluated the effects of steroid inhalation on the deposition pattern of Tc-99m human serum albumin (Tc-99m HSA) radioaerosols in 25 asthma patients. A total of 12 normal controls also underwent the same examination. The pattern of radioaerosol deposition was quantitatively evaluated as the percentage of total deposition (PTD) in the central, intermediate, and peripheral regions of the right lung. The baseline PTD was calculated before and after the administration of a 1-week course of inhalation therapy of 0.05 mg beclomethasone dipropionate four times daily. There were significant differences in PTD between normal controls and asthma patients. Significant differences were also found before and after corticosteroid inhalation therapy in asthma patients. In conclusion, a week-long course of beclomethasone dipropionate inhalation therapy does influence the deposition patterns of aerosols in asthma patients, based on the findings of Tc-99m HSA radioaerosol inhalation lung scintigraphy.

Administration, Inhalation↗

PubMed1995

Evaluation of arthritis in Reiter's disease by bone scintigraphy and radiography.

Tc-99m MDP bone scans were used to evaluate the articular inflammation in 38 patients with Reiter's disease and compared with clinical examination and radiologic findings. Our data showed that Reiter's disease predominantly involves the lower limbs, especially the heels, which may be a characteristic feature of Reiter's disease. Bone scans revealed a high diagnostic sensitivity in the detection of clinical arthritis in all peripheral joints, especially in the small joints of the four limbs. The diagnostic sensitivity of radiography was generally lower than bone scintigraphy. In the presence of positive radionuclide findings, clinical arthritis was found in most joints. The scintigram, however, detects a greater number of abnormalities than does clinical assessment in the sternoclavicular joints, shoulders, metacarpophalangeal joints, and tarsals. Because of its high sensitivity, bone scintigraphy is capable of detecting subclinical arthritis, and might provide more objective evidence of early inflammatory joint disease and additional information regarding the pattern of joint involvement. In view of the advantages of low patient radiation exposure, high sensitivity, and the ability to survey the whole body, we consider bone scintigraphy as useful and better than radiography in the detection of early articular inflammation and in establishing the extent and pattern of arthritis in Reiter's disease.

Adolescent↗

PubMed1995

Collagen induces cytokine production by synovial fluid mononuclear cells in rheumatoid arthritis.

Synovial fluid (SF) mononuclear cells (MNC) from 13 patients with rheumatoid arthritis (RA) and 12 patients with other arthritic diseases (OD) including osteoarthritis (OA), gout and spondyloarthritis (SA) were cultured in the presence of collagen types I and II or lipopolysaccharide (LPS) for 24 h. Interleukin-1 (IL-1), IL-6 and tumor necrosis factor-alpha (TNF-alpha) in the SF and culture supernatants were assayed using ELISA. The results showed that one-half of the RA patients with high SF monocyte count had high SF IL-6 levels that coincided with the high spontaneous release of IL-6 by SF MNC. In the other RA patients with lower SF monocyte count, type II collagen induced significantly higher IL-1 beta than the medium control levels by SF MNC (P < 0.01) or that of the other diseases (P < 0.01). Similarly, type II collagen-induced IL-6 and TNF-alpha production rose significantly (P < 0.01) from SF MNC of RA but less from OD (P < 0.05). In addition, type I collagen could also induce IL-1, IL-6 and TNF-alpha in these samples from RA and OD patients but was less potent than type II collagen. Our results indicate that collagen-induced cytokines may be important in the pathogenesis of the disease.

Arthritis, Rheumatoid↗

PubMed1995

A dominant human leucocyte antigen DR4-Dw15 restricted mycobacterial 65 kDa antigen-specific T-cell immunity in Chinese patients with rheumatoid arthritis.

The human leucocyte antigen DR4-associated immune responses to Mycobacterium tuberculosis 65 kDa heat shock protein were considered to be relevant to the pathogenesis of rheumatoid arthritis (RA). In the Chinese population, DR4-Dw15 was found to be the predominant DR4 subtype in RA. To further define the immune responses associated with DR4-Dw15 molecules, the proliferative responses of peripheral (PBMC) and synovial mononuclear cells (SFMC) to mycobacterial 65 kDa antigen were evaluated. The SFMC of all of our RA patients responded significantly to 65 kDa mycobacterial antigen. The responses of PBMC to this antigen in RA were much lower than those of SFMC. Our results further indicated that relatively low numbers of peripheral antigen-specific T-cells, but not incompetence of peripheral antigen presenting cells, might be related to the observed low responsiveness to 65 kDa antigen in PBMC of RA patients. Of utmost importance, DR4-Dw15 was proved to be one of the major restrictive molecules in mycobacterial 65 kDa antigen-specific immune responses in Chinese RA patients.

Adult↗

PubMed1995

Effects of inhalation of steroids on lung permeability in patients with asthma.

This study evaluated the effect of inhalation of steroids on lung permeability in patients with asthma by measuring the clearance of Tc-99m DTPA aerosol from the alveolar to vascular space. Twenty patients with asthma were studied in the supine position with a gamma camera and the clearance half time (T 1/2) was calculated. The base line lung permeability study was performed before treatment with inhalation of 100 micrograms beclomethasone dipropionate four times daily for 1 week, then the study was repeated. After treatment with inhalation of steroid, there was a change in T 1/2 from 76.4 +/- 37.4 minutes to 86.6 +/- 48.2 minutes (P = 0.08). This preliminary study suggests that lung permeability is not altered by inhaled steroid therapy.

Administration, Inhalation↗

PubMed1995

The change in the distribution of Tc-99m human serum albumin radioaerosols in asthma after a 1-week course of corticosteroid inhalation treatment.

This study evaluated the effects of corticosteroid inhalation on the deposition pattern of Tc-99m HSA radioaerosols in 24 patients with asthma. The homogeneous degree of depositing radioaerosol was quantitatively evaluated using a modified standard score system over both lungs. The baseline scores were calculated before inhalation therapy of 0.05 mg beclomethasone dipropionate four times daily for 1 week. The studies were then repeated after treatment to evaluate the effects of inhalation therapy. After treatment, the scores decreased in 16 of 24 cases (67%), which means that the degree of the bronchial obstruction decreased. The statistical results revealed significant differences in the total homogeneity score (P < 0.001) before and after therapy. Thus, a 1-week course of beclomethasone dipropionate inhalation therapy improves the bronchial obstruction in asthma patients as shown by the quantitative homogeneity score system of the Tc-99m HSA radioaerosol inhalation lung scintigraphy.

Administration, Inhalation↗

PubMed1995

Three-phase abdominal scintigraphy in lupus vasculitis of the gastrointestinal tract.

Gastrointestinal vasculitis is a recognized but frequently misdiagnosed complication of systemic lupus erythematosus. The authors investigated the usefulness of three-phase Tc-99m pyrophosphate abdominal scintigraphy for identifying areas of vasculitis in patients with systemic lupus erythematosus who have gastrointestinal symptoms (diarrhea or abdominal pain). Among patients with gastrointestinal symptoms, 62 of 82 (75%) patients showed positive scan results, suggesting gastrointestinal vasculitis. Among patients without gastrointestinal symptoms, 6 of 43 (13%) patients showed positive scan results. Although three-phase Tc-99m pyrophosphate abdominal scintigraphy cannot provide a definite diagnosis of vasculitis of the gastrointestinal tract, it is a noninvasive and convenient method for suggesting and monitoring gastrointestinal vasculitis.

Abdomen↗

PubMed1995

Antibody to Mycobacterium tuberculosis 65 kDa heat shock protein in patients with rheumatoid arthritis--a survey of antigen-specific antibody isotypes and subclasses in an endemic area of previous tuberculosis infection.

OBJECTIVE: To clarify the significance of the humoral immune response triggered by the Mycobacterium tuberculosis (M.tb) 65 kDa heat shock protein (hsp) in the pathogenesis of rheumatoid arthritis (RA). METHODS: M.tb 65 kDa hsp-specific IgG, IgA, IgM, and IgG subclass antibodies in serum or synovial fluid (SF) of RA and other disease patients were determined by enzyme linked immunosorbent assay (ELISA). RESULTS: RA patients did not show any characteristic increase in mycobacterial 65 kDa hsp-specific antibodies compared with healthy individuals. In contrast, antigen-specific IgG and IgG2 antibody titres in the serum of RA patients were significantly lower than those of patients with tuberculosis and normal controls. In addition, there was also no significant difference in antibody titre between the serum and SF of RA patients, nor was any significant difference found between the SF of RA and Reiter's patients. CONCLUSION: The failure to detect a significant increase in IgG anti-M.tb 65 kDa hsp antibodies in RA patients does not exclude the possibility of microbial immunity in the aetiology of RA. Nevertheless, anti-M.tb 65 kDa hsp antibodies clearly do not appear to be the disease specific markers for RA and their relatively reduced concentrations may argue against their playing a major role in the disease pathogenesis.

Antibodies, Bacterial↗

PubMed1995

Mycobacterium tuberculosis antigen, interleukin 2 and interleukin 2 inhibitor in patients with rheumatoid arthritis.

IL-2 production by the phytohemaglutinin (PHA)-stimulated mononuclear cells (MNC) of peripheral blood (PB) and synovial fluid (SF) from patients with rheumatoid arthritis (RA), other arthritic diseases (OAD) and age-matched normal controls were studied, and the activity of IL-2 inhibitor in sera of studied subject was examined. The significant decreased IL-2 production by PB MNC from the patients with RA (p < 0.05) and OAD (p < 0.05) were observed when compared with normal controls, and no statistical difference was found although IL-2 levels in RA PB were lower than in OAD PB. However, significant statistical difference (p < 0.01) was found when the IL-2 production by RA SF was compared with OAD SF. Serum IL-2 inhibitory factor was examined by IL-2-dependent mouse helper T cell line (HT-2). Significantly higher inhibitory activity was found in RA patients (p = 0.001) compared to OAD and normal control patients. Mycobacterium tuberculosis (MT) antigen was also examined from patients with RA and OAD, and 55.5% of SF from RA patients were positive for MT antigens and none was detected in OAD by a highly specific and sensitive double-antibody sandwich ELISA. However, no correlation between MT antigens, IL-2 levels and IL-2 inhibitory activities were found in patients with RA. Our results and other indicate that rheumatoid SF MNC, IL-2 inhibitor and MT antigen may play important roles in the pathogenesis of RA.

Adult↗

PubMed1995

The relationship of alveolar permeability and pulmonary inflammation in patients with systemic lupus erythematosus.

The alveolar epithelium permeability (AP) in 34 patients with systemic lupus erythematosus (SLE) was measured by Tc-99m DTPA radioaerosol inhalation lung scintigraphy. The degree of AP damage in SLE was represented as the slope of the time-activity curve from the dynamic lung imagings. The patients were divided into two subgroups according to the following two criteria. [A] clinical feature: they were separated as stable or flare stage; and [B] chest X-ray findings: they were separated as positive or negative results. Meanwhile, the quantitative Gallium-67 (Ga) lung scan was performed as Ga uptake index (GUI) to evaluate the severity of inflammation in the lungs in SLE. The results show that [1] there were no significant statistical differences in the degree of AP damage between the two subgroups according to clinical features or chest X-ray findings, and [2] no good correlation between the degree of AP damage and inflammation of the lungs was found. In conclusion, the change of AP in SLE may be a mechanism not related to the presentation of clinical features or chest X-ray findings, and the degree of AP damage in SLE is not related to the severity of pulmonary inflammation.

Adult↗

PubMed1995

Tc-99m DTPA aerosol lung clearance test in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) can affect every organ. Involvement of the lung in systemic lupus erythematosus may be a significant cause of morbidity and mortality. To evaluate alveolar epithelial damage in SLE, we studied lung epithelial permeability by measuring the clearance of inhaled Tc-99m DTPA aerosol. Twenty-three SLE patients without clinical pulmonary manifestations were studied. Of the 23 patients, 16 had normal clearance rates of Tc-99m DTPA (T1/2 > 60mins) and normal chest X-ray findings. A mild increase in the clearance rate was found in 5 cases (T1/2 between 40-60 min) and a significant increase in clearance rate in the remaining 2 (T1/2 < 40mins). Totally, 30% (7/23) of SLE patients have abnormal lung permeability. Of the 7 patients with abnormal clearance of Tc-99m DTPA, 3 had abnormal findings in chest X-rays and four had normal chest X-rays. Our study suggests that the clearance of Tc-99m DTPA aerosol may be a useful complementary study to assess pulmonary involvement in SLE.

Adolescent↗

PubMed1995

Technetium-99m-pyrophosphate scintigraphic findings of intestinal perforation in dermatomyositis.

Gastrointestinal complications are more common in children than in adults and present a serious problem with dermatomyositis. We report on a 66-yr-old man with dermatomyositis who suffered from intestinal perforation. The abdominal plain radiograph revealed only dilatation of the intestinal loops; increased radioactivity, however, was clearly demonstrated in the early 5-min and delayed 3-hr 99mTc-pyrophosphate images.

Aged↗