REAL classification of malignant lymphomas in the Republic of Korea: incidence of recently recognized entities and changes in clinicopathologic features. Hematolymphoreticular Study Group of the Korean Society of Pathologists. Revised European-American lymphoma

BACKGROUND

The clinicopathologic characteristics of malignant lymphomas vary according to geography. The aim of this study was to determine the clinical characteristics of malignant lymphomas and the relative frequency in the Republic of Korea of lymphomas belonging to the newly described REAL (revised European-American lymphoma) classification categories.

METHODS

The Hematolymphoreticular Study Group of the Korean Society of Pathologists conducted a consensus-based morphologic review of a nationwide collection of 1548 malignant lymphomas, including Hodgkin's disease (HD), diagnosed at 23 institutes over a recent 2-year period. Slides stained with hematoxylin and eosin or other immunohistochemical stains were reviewed. All cases were classified according to the histologic criteria proposed by the International Lymphoma Study Group. Clinical data, including age, gender, and site of disease involvement, were reviewed.

RESULTS

The Republic of Korea had lower rates of HD and follicle center lymphoma and higher rates of extranodal lymphoma, diffuse large B-cell lymphoma, and angiocentric lymphoma compared with Western countries. The most frequent subtypes of non-Hodgkin's lymphoma (NHL) were diffuse large B-cell lymphoma, extranodal marginal zone B-cell lymphoma, peripheral T-cell lymphoma, unspecified type, and angiocentric lymphoma, in decreasing order. Compared with a previous nationwide study, the rates for follicular lymphoma and NHL involving the stomach, orbit, and central nervous system were increased. The rate of T-cell NHL in the current study was much lower than that reported in a previous study for the Republic of Korea and was also lower than that reported for other Far East countries. For HD, the relative frequency of nodular sclerosis subtype was higher compared with that in the previous study, and lymphocyte predominance and lymphocyte depletion were lower.

CONCLUSIONS

The occurrence rates for various subtypes of malignant lymphoma in the Republic of Korea are distinct from those in Western countries and similar in many ways to those in other countries in the Far East. Compared with other Far East countries, the Republic of Korea has a higher rate of extranodal lymphoma, rare adult T-cell lymphoma, and a relatively low rate of T-cell lymphomas. It appears that over time there have been changes in the relative rates for follicular lymphoma, subtypes of Hodgkin's disease, and gastric and orbital lymphoma. The authors attribute these changes primarily to refined criteria for diagnosing new clinicopathologic entities.

Oral drug of choice in carpal tunnel syndrome

BACKGROUND

Conservative treatment of mild to moderate carpal tunnel syndrome (CTS) is variable.

OBJECTIVE

To evaluate the effectiveness of commonly used oral medications such as diuretics, nonsteroid anti-inflammatory drugs (NSAIDs), and steroids in the treatment of CTS.

METHODS

Prospective, randomized, double-blind and placebo-controlled study of patients with clinical symptoms and signs of CTS, confirmed by standard electrodiagnosis. Baseline assessments included a standardized symptom questionnaire, rating five categories of symptoms (pain, numbness, paresthesia, weakness/clumsiness, and nocturnal awakening) on a scale from 0 (no symptoms) to 10 (severe). The total score in each of the five categories was termed the global symptom score (GSS). After baseline assessment, patients were randomized to the following treatment arms: 1) 4 weeks of placebo (n = 16); 2) 4 weeks of diuretic (trichlormethiazide, 2 mg daily; n = 16); 3) 4 weeks of NSAID-slow release (SR) (tenoxicam-SR, 20 mg daily; n = 18); and 4) 2 weeks of prednisolone, 20 mg daily, followed by another 2-week dosage of 10 mg daily (n = 23). Results of follow-up assessments in the second and the fourth weeks were identical to baseline scores. The changes in GSS were analyzed to determine the statistical difference.

RESULTS

No significant reduction from baseline GSS was seen at second, and fourth weeks in the placebo, NSAID-SR, and diuretic groups. However, the mean score at 4 weeks in the steroid group decreased significantly from a baseline of 27.9 +/- 6.9 to 10 +/- 7.4.

CONCLUSION

For patients with mild to moderate CTS who opt for conservative treatment, corticosteroids are of greater benefit.

Suppression of mouse skin tumor promotion and induction of apoptosis in HL-60 cells by Alpinia oxyphylla Miquel (Zingiberaceae)

There have been considerable efforts to search for naturally occurring substances for the intervention of carcinogenesis. Many components from dietary or medicinal plants have been identified that possess substantial chemopreventive properties. An example is curcumin (Curcuma longa Linn., Zingiberaceae), which has been shown to inhibit tumor promotion in experimental carcinogenesis. Alpinia oxyphylla Miquel, another plant of the ginger family used in oriental herbal medicine, contains diarylheptanoids whose structures are analogous to that of curcumin. In the present study, we have tested A.oxyphylla for its ability to suppress tumor promotion. Thus, topical application of the methanolic extract of dried fruits of A.oxyphylla significantly ameliorated 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced skin tumor promotion as well as ear edema in female ICR mice. In another study, treatment of HL-60 cells with the methanolic extract of A.oxyphylla significantly reduced the viability of the cells and also inhibited DNA synthesis. Microscopic examination of the treated cells showed characteristic morphology of apoptosis. Furthermore, cells treated with the extract of A.oxyphylla exhibited internucleosomal DNA fragmentation in time- and concentration-dependent manners. TPA-stimulated generation of superoxide anion in differentiated HL-60 cells was also blunted by A.oxyphylla. Taken together, these findings suggest that A.oxyphylla possesses potential chemopreventive and antitumorigenic activities.

Inhibitory effects of [6]-gingerol, a major pungent principle of ginger, on phorbol ester-induced inflammation, epidermal ornithine decarboxylase activity and skin tumor promotion in ICR mice

A wide array of phytochemicals have been shown to possess potential cancer chemopreventive properties. Ginger contains pungent phenolic substances with pronounced antioxidative and antiinflammatory activities. In the present study, we have determined the antitumor promotional activity of [6]-gingerol, a major pungent principle of ginger, using a two-stage mouse skin carcinogenesis model. Topical application of [6]-gingerol onto shaven backs of female ICR mice prior to each topical dose of 12-O-tetradecanoylphorbol-13-acetate (TPA) significantly inhibited 7,12-dimethylbenz[a]anthracene-induced skin papillomagenesis. The compound also suppressed TPA-induced epidermal ornithine decarboxylase activity and inflammation.

Epigallocatechin suppression of proliferation of vascular smooth muscle cells: correlation with c-jun and JNK

1. The mechanisms of the antiproliferative effect of epigallocatechin, one of the catechin derivatives found in green tea, in vascular smooth muscle cells were studied. The proliferative response was determined from the uptake of tritiated thymidine. 2. In the concentration range of 10(-6) to 10(-4) M, catechin, epicatechin, epigallocatechin, epicatechin gallate and epigallocatechin, epigallocatechin gallate, concentration-dependently inhibited the proliferative response stimulated by serum in rabbit cultured vascular smooth muscle cells. Catechin and epicatechin were less effective in inhibiting the serum-stimulated smooth muscle cell proliferation, indicating that the galloyl group may be important for full inhibitory activity. 3. Epigallocatechin (EGC) inhibited the proliferative responses in different cells including rat aortic smooth muscle cells (A7r5 cells), rabbit cultured aortic smooth muscle cells, human coronary artery smooth muscle cells, and human CEM lymphocytes in a concentration-dependent manner. The possible mechanisms of the antiproliferative effect of EGC were further studied in A7r5 cells. 4. The membranous protein tyrosine kinase activity stimulated by serum in A7r5 cells was significantly reduced by 10(-5) M EGC. In contrast, the cytosolic protein kinase C activity stimulated by phorbol ester was unaffected by directly incubating with EGC (10(-6)-10(-4) M). 5. We also performed Western blot analysis using the anti-phosphotyrosine monoclonal antibody PY20. EGC (10(-5) M) reduced the levels of tyrosine phosphorylated proteins with different molecular weights, indicating that EGC may inhibit the protein tyrosine kinase activity or stimulate the protein phosphatase activity. 6. Reverse transcription-polymerase chain reaction analysis of c-fos, c-jun and c-myc mRNA levels demonstrated that c-jun mRNA level after serum-stimulation was significantly reduced by 10(-5) M EGC. However, the reduction of c-fos and c-myc mRNA levels by 10(-5) M EGC did not achieve significance. 7. Western blot analysis using the antibody against JNK (c-jun N-terminal kinase) and ERK (extracellular signal-regulated kinase) demonstrated that the level of phosphorylated JNK1, but not phosphorylated ERK1 and ERK2, was reduced by 10(-5) M EGC. Direct measurement of kinase activity by immune complex kinase assay confirmed that JNK1 activity was inhibited by EGC treatment. These results demonstrate that EGC preferentially reduced the activation of JNK/SAPK (stress-activated protein kinase) signal transduction pathway. 8. It is suggested that the antiproliferative effect of epigallocatechin on vascular smooth muscle cells may partly be mediated through inhibition of protein tyrosine kinase activity, reducing c-jun mRNA expression and inhibiting JNK1 activation. Tea catechins may be useful as a template for the development of drugs to prevent the pathological changes of atherosclerosis and post-angioplasty restenosis.

Effects of estradiol and progesterone on cytochrome P4501A1 expression in Hepa 1c1c7 cells

The effects of estradiol and progesterone on the expression of cytochrome P4501A1 were investigated in Hepa 1c1c7 cells. Both steroids, at 10 microM concentration, increased P4501A1-mediated 7-ethoxyresorufin O-deethyalase activity and amounts of its immunoreactive protein and CYP1A1 mRNA. Gel shift assay revealed that the steroids could induce both AhR transformation and binding of the ligand-AhR complex to its specific DNA recognition site. Transient transfection demonstrated that 5'flanking region of CYP1A1 could respond to the steroid action. The competitive binding assay showed that the steroids bound to AhR with moderate affinity. These results suggested that steroidal structure can be AhR ligands and induce CYP1A1 expression in AhR-dependent manner.

Simultaneous measurement of multichannel laser linewidths and spacing by use of stimulated Brillouin scattering in optical fiber

A novel method for measuring the linewidth of each laser and channel spacing in a multichannel transmission system is presented. Using the dependence of the Stokes frequency shift on the pump wavelength in stimulated Brillouin scattering, we are able to construct a delayed self-heterodyne interferometer that can measure the linewidths and channel spacing simultaneously.

Comparing the first and second hundred AIDS cases in Hong Kong

OBJECTIVES

To study the clinical and epidemiological features of the first 200 AIDS patients in Hong Kong.

METHOD

A retrospective analysis of the data reported to the Department of Health. The patients were divided into two groups of first 100 and second 100 cases for comparison so as to discern the temporal changes.

RESULTS

The first 100 AIDS cases were reported from February 1985 through to March 1994 (122 months) while the second 100 in the following 26 months. For both groups, they were predominantly male (94%, 89%), Chinese (66%, 74%) who acquired HIV via sex (83%, 91%). The proportion of Caucasians and homo/bi-sexual contacts in first and second 100 cases have fallen from 26% to 12% (p = 0.012), and from 53% to 31% (p = 0.006) respectively. For primary AIDS-defining illness (ADI), the frequency of Pneumocystis carinii pneumonia (PCP) has decreased (46% to 30%, p = 0.03) while that of tuberculosis (10%, 19%) and Penicillium marneffei (5%, 14%) infection have increased. Mycobacterium avium intracellualare and cytomegalovirus infection have become commoner subsequent ADIs. Frequency of PCP (22%, 9.5%) as the cause of death have dropped while that of tuberculosis has risen (4.8%, 14.3%). Median survival probability had improved from 7.3 months for the first half of patients to 11.9 months for the second half.

CONCLUSION

Incidence of PCP has declined among local AIDS patients whereas tuberculosis, penicilliosis, MAI, and CMV diseases have increased. Survival chance of AIDS patients has improved over the years.

Chronic refractory tibia osteomyelitis treated with adjuvent hyperbaric oxygen: a preliminary report

BACKGROUND

Refractory osteomyelitis is a serious disease that fails to respond to aggressive medical and surgical treatment. A plethora of alternative therapies have evolved. Hyperbaric oxygen has been proven to enhance bone and soft tissue healing in many in vitro and in vivo studies. This article presents the preliminary results of adjunctive hyperbaric oxygen therapy in patients with refractory osteomyelitis.

MATERIALS AND METHODS

Fifteen patients who were diagnosed with refractory tibia osteomyelitis were treated prospectively with adjunctive hyperbaric oxygen therapy, aggressive surgical debridement, and parenteral antibiotic treatment. The effectiveness was evaluated with an average follow-up of 17.2 months.

RESULTS

The hyperbaric oxygen therapy averaged 26 daily sessions. Successful treatment was achieved in 13 patients (86%). The mean length of treatment was 45 days. The preliminary results are comparable with other series.

CONCLUSION

Hyperbaric oxygen is effective as an adjunct to aggressive medical and surgical management in refractory osteomyelitis. A precise clinical staging system for patient selection and treatment organization is imperative to successful outcome.

In vitro cytotoxic activity of 1-decarboxy-3-oxo-ceanothic acid in a human ovarian adenocarcinoma cell line

The effect of a novel pentacyclic triterpene, 1-decarboxy-3-oxo-ceanothic acid (DOCA) on DNA synthesis, DNA degradation and programmed cell death was examined in human ovarian adenocarcinoma (OVCAR-3) cells. OVCAR-3 cells exposed to various concentrations of DOCA for 30 h displayed a dose-dependent inhibition of DNA synthesis. Morphologically, treatment with 10 microg/ml of DOCA for 24 h and 72 h resulted respectively in reduction in cell volume and condensation of nuclear structures. By agarose gel analysis, DNA fragmentation with the characteristic pattern of inter-nucleosomal ladder was observed after cells were treated with 2.5 microg/ml of DOCA for 24 h. Both cell death and DNA fragmentation caused by this compound were partially inhibited by the protein synthesis inhibitor cycloheximide, suggesting that the apoptotic process caused by DOCA requires synthesis of new proteins. On the other hand, no apparent double-stranded DNA breaks were detected after cells were incubated with 2.5 microg/ml of DOCA for 24 h, indicating that DNA damage was not a preceding event for apoptosis induced by this compound. Taken together, our results demonstrate that the cytotoxic effect of DOCA is mediated, at least in part, by the induction of apoptosis.

Primary liver abscess due to Klebsiella pneumoniae in Taiwan

Pyogenic liver abscess is an uncommon complication of intra-abdominal or biliary tract infection and is usually a polymicrobial infection associated with high mortality and high rates of relapse. However, over the past 15 years, we have observed a new clinical syndrome in Taiwan: liver abscesses caused by a single microorganism, Klebsiella pneumoniae. We reviewed 182 cases of pyogenic liver abscess during the period September 1990 to June 1996; 160 of these cases were caused by K. pneumoniae alone, and 22 were polymicrobial. When patients with K. pneumoniae liver abscess were compared with those who had polymicrobial liver abscess, we found higher incidences of diabetes or glucose intolerance (75% vs. 4.5%) and metastatic infections (11.9% vs. 0) and lower rates of intra-abdominal abnormalities (0.6% vs. 95.5%), mortality (11.3% vs. 41%), and relapse (4.4% vs. 41%) in the former group. Liver abscess caused by K. pneumoniae is a new clinical syndrome that has emerged as an important infectious complication in diabetic patients in Taiwan.

Clinicopathologic study of basaloid squamous carcinoma of the upper aerodigestive tract

The clinicopathologic and immunohistochemical characteristics of nine cases of basaloid squamous carcinoma (BSC) of the upper aerodigestive tract are reported, along with the results of an in situ hybridization for human papilloma virus (HPV) DNA. The cases were selected through a review of 237 head and neck carcinomas, and were located in the supraglottic larynx (5), hypopharynx (2), and the base of tongue (2). The patients were 7 males and 2 females with the mean age of 62. BSCs were histologically characterized by lobules and nests of basaloid cells with scanty cytoplasm, comedonecrosis and adenoid features, and by concomitant presence of squamous cell carcinoma. Immunohistochemically, all BSCs showed positivity for high molecular weight cytokeratin (HMW CK) with heterogeneous or diffuse staining pattern, but lacked reactivity for neuroendocrine markers and bcl-2 oncoprotein. No HPV DNA was detected in BSCs. This study reaffirms that BSC is a rare carcinoma with a peculiar topographic distribution and distinct pathologic features.

Re-treatment of chronic hepatitis C with consensus interferon

A multicenter, open-label, phase 3 study was conducted in 337 patients with chronic hepatitis C virus (HCV) infection who had either not responded to previous interferon therapy or had relapsed after discontinuation of therapy with either consensus interferon (9 microg) or interferon alpha-2b (3 million U) three times a week for 24 weeks. Patients were randomized to receive a higher dose of consensus interferon (15 microg) administered subcutaneously three times a week for 24 or 48 weeks and then were observed for an additional 24 weeks. Patients who had relapsed after prior interferon therapy were more likely to have a sustained alanine aminotransferase response and HCV RNA response (as measured by reverse transcription-polymerase chain reaction with a sensitivity of < 100 copies/mL) than were patients who had not responded to prior interferon therapy. For relapsers, the sustained HCV RNA response rate was 58% (48 weeks) and 28% (24 weeks). The sustained alanine aminotransferase response for relapsers was 52% (48 weeks) and 39% (24 weeks). The sustained HCV RNA response rate among prior nonresponders was 13% (48 weeks) and 5% (24 weeks), and the sustained alanine aminotransferase response rate for nonresponders was 17% (48 weeks) and 12% (24 weeks). The administration of 15 microg of consensus interferon was well tolerated and was not associated with an increase in the incidence of side effects. These data demonstrate that re-treatment with 15 microg of consensus interferon is safe and effective therapy for patients with chronic hepatitis C who have either not responded to previous interferon therapy or relapsed after discontinuation of interferon therapy.

Nuclear overexpression of bcl-2 oncoprotein during the progression of human stomach cancer

We unexpectedly observed strong nuclear overexpression of bcl-2 protein in advanced stomach cancer. As far as we know, such expression has not yet been reported. To investigate the significance of nuclear expression of bcl-2 protein in gastric carcinoma, we immunohistochemically analyzed bcl-2 overexpression in a gastric carcinogenic sequence, including 19 tubular adenomas (TA), 20 early carcinomas (EGC), and 20 advanced carcinomas (AGC). While TA displayed a specific granular and supranuclear cytoplasmic staining pattern, adenocarcinomas showed a strong nuclear staining pattern. Nuclear staining of bcl-2 was observed in 50% of AGC, 30% of EGC, and 10% of TA; cytoplasmic staining, on the other hand, was observed in all TA, 5% of EGC, and 10% of AGC. Nuclear bcl-2 overexpression differed according to the histologic type of AGC, occurring in 67% of the diffuse type and 25% of the moderately-to-well differentiated type. In the diffuse type, nuclear bcl-2 positive AGC predominated. In metastatic lesions, the pattern of bcl-2 immunostaining was almost identical to that seen in primary tumor. These results suggest that nuclear expression of bcl-2 may be related to malignant transformation in the stomach and is frequently associated with diffuse type advanced gastric adenocarcinomas.

Bone healing of tibial lengthening is enhanced by hyperbaric oxygen therapy: a study of bone mineral density and torsional strength on rabbits

We investigated the effect of intermittent hyperbaric oxygen (HBO) therapy on the bone healing of tibial lengthening in rabbits. Twelve male rabbits were divided into two groups of six animals each. The first group went through 2.5 atmospheres absolute of hyperbaric oxygenation for 2 hours daily, and the second group did not go through hyperbaric oxygenation. Each animal's right tibia was lengthened 5 mm using an uniplanar lengthening device. Bone mineral density (BMD) study was performed for all of the animals at 1 day before operation and at 3, 4, 5, and 6 weeks after operation. All of the animals were killed at 6 weeks postoperatively for biomechanical testing. Using the preoperative BMD as an internal control, we found that the BMD of the HBO group was increased significantly compared with the non HBO group. The mean %BMD at 3, 4, 5, and 6 weeks were 69.5%, 80.1%, 87.8%, and 96.9%, respectively, in HBO group, whereas the mean %BMD were 51.6%, 67.7%, 70.5%, and 79.2%, respectively, in non-HBO group (two tailed t test, p < 0.01, p < 0.01, p < 0.01, and p < 0.01 at 3, 4, 5, and 6 weeks, respectively). Using the contralateral nonoperated tibia as an internal control, we found that torsional strength of lengthened tibia of the HBO group was increased significantly compared with the non-HBO group. The mean percent of maximal torque was 88.6% in HBO group at 6 weeks, whereas the mean percent of maximal torque was 76.0% in non-HBO group (two-tailed t test, p < 0.01). The results of this study suggest that the bone healing of tibial lengthening is enhanced by intermittent hyperbaric oxygen therapy.

Changing behavioural pattern of drug users in Hong Kong 1991-1995

AIMS

To analyse the temporal changes in demography and drug-taking behaviours of a cohort of drug users in Hong Kong.

DESIGN

An analysis of records of clients over a 5-year period.

SETTING

Shek Kwu Chau Treatment and Rehabilitation Centre, a large residential service offering voluntary rehabilitation programmes for male drug users in Hong Kong.

MEASUREMENTS

The following parameters were analysed for all admissions between 1991 and 1995: duration of drug-taking, route(s) of drug administration, type of drugs abused, practice of injection and needle-sharing, time since last needle-sharing, and expenditure on drugs.

FINDINGS

A total of 10,353 admissions were recorded in the 5-year period from 1991 to 1995, of whom 2853 (27.6%) were new admissions. The mean age was 36 years. There was a significant increase in new admission in those between the age of 13 and 19. Almost all clients were heroin users. The needle-sharing rates fell from over 20% in 1991 to < 5% in 1995. Needle-sharing was more common in younger clients. The decline in the rate of needle-sharing was especially significant in those between the age of 20 and 39.

CONCLUSION

The proportion of young drug users in the study population in Hong Kong has risen over the 5-year period. The prevalence of high-risk drug-taking behaviours had declined, which might have contributed to the low HIV rates in the community.

Naturalistic action impairment in closed head injury

The authors sought to determine whether errors of action committed by patients with closed head injury (CHI) would conform to predictions derived from frontal lobe theories. In Study 1, 30 CHI patients and 18 normal controls performed routine activities, such as wrapping a present, under conditions of graded complexity. CHI patients committed more errors even on the simplest condition; but, except for a higher proportion of omitted actions, their error profile was very similar to that of controls. Study 2 involved a subset of patients whose performance in Study 1 was within normal limits. When these high functioning patients were asked to perform the routine tasks under still more taxing conditions, they, too, committed errors in excess of the control group. Accounts based on frontal mechanisms have a difficult time explaining the overall pattern of findings. An alternative based on limited-capacity resources is suggested.

Two-phase bioconversion product recovery by microfiltration I. Steady state studies

Recovery of an aqueous bioconversion product from complex, two-phase Pseudomonas putida broths containing 20% (v/v) soybean oil presents a significant challenge for downstream processing. Although not used before in multiple-phase separation for complex biotech products, crossflow filtration employing ceramic filters is one of the most attractive options which allow the design of integrated, continuous bioconversion processes. As a first attempt, we studied multichannel, monolithic ceramic membranes of different nominal pore sizes and lumen diameters under steady-state conditions. The best performance was obtained with 0.2-microm-pore/3-mm-lumen membrane, which completely rejected both cells and oil droplets from the permeate, creating a clear aqueous product stream. Although the same separation was achieved, the 50K molecular weight cut-off (MWCO) ultrafilter showed greater irreversible but similar reversible resistance, in addition to an order-of-magnitude higher membrane resistance. Larger nominal pore microfilters, such as 0.45 and 1.0 microm, experienced both cell and oil leakage even at low transmembrane pressure (10 psig). Attributed to greater shear at the same recirculation rate, smaller lumen filters did provide greater permeate flux. However, for practical purposes, the 0. 2-microm-pore/4-mm-lumen ceramic membrane was chosen for further evaluation. Transmembrane pressures up to 50 psig provided only marginal gains in filtration performance, whereas increasing shear rate resulted in linear increases in steady-state flux, presumably due to formation of shear-sensitive, complex gel/oil/cell layer near the membrane surface. A nominal shear rate of 9200 s-1 and 20 psig transmembrane pressure were chosen as optimal operating conditions. Additional studies in a clean system revealed that as low as 5% (v/v) soybean oil in deionized (DI) water resulted in an order-of-magnitude decline in steady-state permeate flux. Breakthrough of oil droplets occurred at 35 psig transmembrane pressure. The severe fouling and breakthrough phenomena disappeared in the presence of washed cells for transmembrane pressure up to 43 psig, implying an oil/cell layer coating the membrane surface, thus preventing oil penetration. Serious membrane fouling was also experienced in microfiltration of oil-free, cell-free supernatant and oil-free whole broth. Consequently, soluble proteins/surfactants were suspected to be the major membrane foulants. Interestingly, soybean oil up to 30% (v/v) enhanced the flux, presumably through complicated interactions with the major foulants. Regeneration of membrane was best achieved with protease and hot caustic/bleach treatments, supporting the hypothesized fouling mechanisms mentioned above. This work provides process and system information for batch microfiltration runs in the future, to be reported elsewhere as Part II of this work.

Syntaxin 12, a member of the syntaxin family localized to the endosome

We have cloned a new member of the syntaxin family of proteins. The open reading frame encodes a polypeptide of 272 amino acids with potential coiled-coil domains and a C-terminal hydrophobic tail. Northern blot analysis showed that the transcript is fairly ubiquitous. A soluble recombinant form of the polypeptide without the hydrophobic region binds to alpha-SNAP (soluble N-ethylmaleimide-sensitive factor attachment protein) and syndet/SNAP-23 in vitro. Polyclonal antibody raised against the recombinant protein recognized a 39-kDa protein in the membrane fraction of cell lysates. Indirect immunofluorescence studies using the polyclonal antibody showed that the protein is localized to intracellular membrane structures. Selective permeabilization studies with digitonin and saponin indicate that the epitope(s) recognized by the antibody is expose to the cytoplasm, consistent with the predicted orientation characteristic of SNAP receptor molecules. Morphological alterations of the staining pattern of the protein with brefeldin A and wortmannin treatment indicate that the protein is localize to the endosome. The cDNA we have cloned apparently corresponded to three previously described expressed sequence tags named as syntaxins 12, 13, and 14, respectively. We therefore propose to retain the name syntaxin 12 for this protein.

Measurement of anti-dsDNA: a comparative study of two ELISA and the Crithidia assay

We compared the measurement of anti-dsDNA by a commercial ELISA test (DIASTAT), an in-house ELISA and the Crithidia luciliae assay in cross-sectional sera samples of 209 systemic lupus erythematosus (SLE) patients and 64 patients with a variety of rheumatological, autoimmune and non-autoimmune diseases in Hong Kong. The Crithidia assay was found to be the least sensitive (17%) but most specific (95%) method for detection of a positive result in SLE patients. The DIASTAT assay has a higher sensitivity (68%) but lower specificity (80%) than the in-house ELISA test (32% sensitivity and 89% specificity). The positive predictive value of the three assays are comparable at 90-92% while DIASTAT had the highest negative predictive value (44%). There was good linear correlation (r = 0.7) between the two ELISAs. ELISA can serve as a useful screening test for anti-dsDNA in SLE patients and doubtful cases can then be confirmed by another method such as radio-immunoassay.

Alteration of signal-transducing molecules in tumor-infiltrating lymphocytes and peripheral blood T lymphocytes from human colorectal carcinoma patients

Tumor development or growth is accompanied by impaired immune responses, such as a poor proliferative response or down-regulated cytolytic T lymphocyte activity. Although recent reports have suggested that modification of the signal-transducing molecule is responsible for impaired immune responses in tumor-bearing hosts, the causes of defective immune function are not yet completely understood. Furthermore, the clinical significance of the findings is not yet clear. In this study, we investigated the alteration of several signal-transducing molecules in peripheral blood T lymphocytes (T-PBL) as well as in tumor-infiltrating lymphocytes (TIL) from human colorectal carcinoma patients and their relationship with the impaired host immune responses. A greater reduction in CD3zeta chain level was observed in TIL than in T-PBL from tumor-bearing hosts. CD3zeta chain reduction in T-PBL correlated with the clinicopathological stage of a tumor, especially with the status of lymph node metastasis. The levels of p56lck and p59fyn protein tyrosine kinase in T-PBL were also compared between tumor-bearing hosts and normal healthy volunteers. In T-PBL from tumor-bearing hosts, expression of protein tyrosine kinase p59fyn was significantly lower than that of p56lck. However, the level of CD3zeta chain expression did not correlate with T lymphocyte functions such as T lymphocyte proliferative response or allogeneic target cell lysis.

The effects of liver transplantation and cyclosporine on bile formation and lipid composition: an experimental study in the rat

BACKGROUND/AIMS

Hepatic graft dysfunction is a major management problem in the early post-liver transplantation period. Our aims were to study how liver transplantation per se affects bile formation, and to investigate the role of cyclosporine in the pathogenesis of early graft dysfunction.

METHODS

Syngeneic liver transplantation used male Lewis rats. Two weeks after transplantation, the rats were randomly assigned to receive either daily subcutaneous injections of cyclosporine 10 mg/kg for 1 week (n=8), or daily saline injections (Placebo, n=8). 24-h bile collections were performed 18 h after the last injection. Eight non-transplanted rats served as controls.

RESULTS

Liver transplantation per se (Placebo) significantly increased basal bile flow (51%), particularly that portion which was bile salt-independent flow (81%), but did not impair bile salt kinetics or biliary lipid composition. Cyclosporine reduced basal bile flow and bile salt-independent flow by 41% and 30%, respectively. Bile salt synthesis was 52% suppressed, leading to a 22% decrease in the bile salt pool size. The recycling frequency of the bile salt pool was unaffected. The drug inhibited bile salt (37%) and phospholipid (23%) outputs; cholesterol secretion remained unaltered. This significantly elevated the cholesterol saturation of bile (25%).

CONCLUSIONS

Liver transplantation per se is choleretic and does not impair bile formation or lipid composition in this inbred rat model. Parenteral administration of high-dose cyclosporine induces cholestasis by inhibiting bile salt secretion and BSIF. Bile salt synthesis is down-regulated and the bile salt pool size decreased. The drug adversely affects biliary lipid composition by differential inhibition of bile salt and phospholipid outputs relative to an unchanged cholesterol secretion.

A novel type of structurally simple nonpeptide inhibitors for alpha-chymotrypsin. Induced-fit binding of methyl 2-allyl-3-benzenepropanoate to the S2 subsite pocket

Unexpectedly, methyl and benzyl esters of 2-allyl-3-benzenepropanoic acid were found to be not substrates but potent competitive inhibitors for alpha-chymotrypsin. The inhibitory property of the structurally simple nonpeptidic compounds is ascribed to their high binding affinity to the enzyme at the S2 rather than S1 subsite pocket. These inhibitors exist in a flexible form in solution, but as they bind to the enzyme bulky contrained conformers present in a minute concentration play an important role, forming tighter enzyme.inhibitor complexes by binding to the large hydrophobic S2 pocket. The contrained conformers are thought to be resulted from intramolecular CH/pi interactions between a vinylic proton and the aromatic pi-electron cloud in the inhibitor molecules. These compounds constitute novel examples of the induced-fit binding inhibitor of possibly simplest structure.