Effects of artificial liver support system on patients with acute or chronic liver failure

AIMS

Acute on chronic liver failure (AoCLF) is associated with a high mortality rate. Artificial liver support system (ALSS) is useful to bridge patients with liver failure to liver transplantation or to regenerate their own livers. The aims of this prospective study were to investigate the effects of ALSS on clinical manifestations, liver function, and 30-day survival to probe the factors related to mortality in patients with AoCLF.

METHODS

In this study, 338 enrolled patients with AoCLF who received ALSS treatment for 1 to 8 sessions, were compared with 312 patients treated with conventional medications.

RESULTS

Clinical manifestations and liver functions were significantly improved, namely, decreased levels of serum transaminases, total bilirubin, and bile acid, as well as increased levels of serum albumin following ALSS treatment. The 30-day survival rates of the patients who received ALSS versus controls were 47.9% versus 34.6%, respectively (P = .01). The MELD score and the stage of hepatic encephalopathy were highly associated with mortality (P < .001), but the sessions of ALSS showed a positive relation to the 30-day survival (P < .05).

CONCLUSIONS

ALSS appears to be efficacious and safe for the treatment of patients with AoCLF. Both model for end-stage liver disease (MELD) score and hepatic encephalopathy are useful to predict the mortality of patients.

Cloning and characterization of rat spermatid protein SSP411: a thioredoxin-like protein

In an attempt to identify new sperm-specific genes that are involved in sperm maturation, fertilization, and embryo development, such as the mammalian ortholog of the sperm-supplied protein gene, spe-11, in Caenorhabditis elegans, we cloned and characterized a new spermatid-specific protein gene, ssp411, from adult rat testes. The ssp411 cDNA shared >85% sequence identity with an unnamed human protein, FLJ21347, and an uncharacterized mouse testicular protein called transcript increased in spermiogenesis 78 (TISP78). A 2.8-kb ssp411 mRNA was expressed in a testis-specific and age-dependent manner; the mRNA was evident at 28 days and remained at high levels throughout adulthood. An SSP411 protein of molecular weight 88 000 was detected in testicular extracts by Western blot analysis. Ssp411 mRNA and SSP411 protein, as analyzed by in situ hybridization and immunohistochemistry, were both expressed in a stage-dependent fashion during the cycle of the seminiferous epithelium. The ssp411 mRNA was predominantly localized to round and elongated spermatids, with maximal expression at stages VII-XII. The SSP411 protein was mainly observed in elongated spermatids and reached its highest levels during stages V-VI. A conserved thioredoxin-like domain was detected in the N-terminal region of SSP411 and its orthologs. An analysis of the predicted 3-dimensional structural modeling and folding pattern further suggested that SSP411 is identifiable as a member of thioredoxin family. In summary, we have identified a new rat spermatid protein gene, ssp411, and its orthologs in human and mouse and demonstrated that SSP411 might belong to a testis-specific thioredoxin family. This suggests that SSP411 may play a role in sperm maturation, fertilization, and/or embryo development, as has been shown in thioredoxin family.

[Second sampled survey on the distribution of human parasites in Zhejiang Province]

OBJECTIVE

Twenty-six species of human parasites were recorded in Zhejiang Province in 1987-1989 as a part of the national investigation on the distribution of human parasites, and the total prevalence was 80.2%. In order to find out possible changes on the composition of parasite species and decrease of prevalence after control intervention particularly mass chemotherapy in the past years and provide evidence for an improved control strategy, the second sampled survey was carried out from 1998 to 1999.

METHODS

Ten counties were identified randomly out of 28 counties where the last survey was conducted following the same sampling method. Same technics were used for case detection and data processing.

RESULTS

The total infection rate in a sample of 15,698 was 22.84% was 22.84% in 30 investigation spots in 10 counties, and 17 species of parasites were revealed. The overall prevalence was reduced by 71.51% in comparison to that of 1989, and the number of parasite species was 17, 9 less than that of the last investigation.

CONCLUSIONS

The prevalence of human parasites has greatly declined in this province due to the socioeconomic development and adoption of comprehensive control measures focusing on mass chemotherapy in the past decade.

Serum soluble transferrin receptor reflects erythropoiesis but not iron availability in erythropoietin-treated chronic hemodialysis patients

BACKGROUND

The diagnosis of iron deficiency using the current commonly used tests is usually difficult in hemodialysis patients. Soluble transferrin receptor (sTfR) has caught the attention of physicians recently as regards its use as a parameter for the evaluation of iron status. This study was conducted in order to evaluate the correlation of serum soluble transferrin receptor (sTfR) concentration with hematological parameters and iron profiles, in the role of identifying iron deficiency among dialysis patients.

METHODS

Seventy-three patients having received chronic hemodialysis and stable maintenance recombinant human erythropoietin (rHuEPO) therapy were included. Iron, total iron-binding capacity, ferritin and sTfR were measured in the first week. Following this, these patients began to receive intravenous iron dextran (2 mg/kg/week) for 4 weeks. The hematocrit (Hct), hemoglobin (Hb) levels and reticulocyte counts were evaluated weekly. At the beginning of fifth week, the sTfR level was measured again. Patients were classified as belonging to one of the following groups: serum ferritin < 100 microg/L - absolute iron-deficient group; initial ferritin level > or = 100 microg/L with an increase in hemoglobin of greater than 1 g/dL at the end of the study occult iron deficiency group; others - non iron-deficient group.

RESULTS

Seventy-one patients completed the study. The concentration of sTfR was positively correlated with Hct, Hb and reticulocyte index at the beginning (r = 0.236, p = 0.047; r = 0.257, p = 0.04; r = 0.401, p < 0.01, respectively) and at the end of the study (r = 0.384, p < 0.01; r = 0.338, p < 0.01; r = 0.427, p < 0.001, respectively). After 4 weeks of iron and rHuEPO therapy, the sTfR concentration increased, rather than declined, from 21.85 +/- 8.06 nM to 23.76 +/- 7.42 nM (p = 0.04) and the change was positively correlated with the changes in Hct, Hb and reticulocyte index. The administered rHuEPO doses did not differbetween the iron deficiency group (absolute deficiency, n = 3; occult deficiency, n = 10) and non-iron deficiency group (n = 58). The sTfR levels failed to identify the occult iron deficiency group because there was no difference between occult iron-deficient and non-iron-deficient patients (24.73 +/- 9.09 nM versus 21.60 +/- 7.89 nM, p = 0.34). Instead, transferrin saturation (TS) could be a differential marker between the 2 groups (19.0 +/- 10.9% versus 30.1 +/- 12.7%, p = 0.012).

CONCLUSION

The serum sTfR concentration is indeed an appropriate marker for erythropoiesis. The erythropoitic effect of administered rHuEPO could mask the effect of iron status on the sTfR concentration. This might make the sTfR concentration no longer an appropriate index to identify the presence of occult iron deficiency. Thus, TS and ferritin currently remain better methods for the evaluation of iron status in rHuEPO-treated chronic hemodialysis patients.

Additive effect of Interleukin-12 and Interleukin-18 on the T-helper cell pathway of malignant pleural effusion

Interleukin-18 (IL-18) is a novel cytokine with interferon-gamma (IFN-gamma)-inducing activity, thus favoring the T-helper type 1 (Th-1) pathway. The present study attempts to define the role of IL-18 on the functions of lymphocytes isolated from malignant pleural effusions (EAL, effusion-associated lymphocytes). EAL from 10 patients with malignant pleural effusion were incubated with IL-2, IL-12, or IL-18 with/without a alpha CD3 antibody. ELISA, proliferation, and cytotoxicity assays were performed. IL-18 alone was found to have no significant effect on EAL in terms of cytokine production, lymphocyte proliferation, or cytotoxicity against tumor targets. IL-18 also had no significant additive or synergistic effect on IL-2, IL-12, or alpha CD3 co-cultured EAL. However, when IL-18 was used with IL-12, the highest IFN-gamma/IL-10 ratio was derived, suggesting that these two cytokines had an additive effect in leading EAL from the Th-2 to the Th-1 pathway. Furthermore, 1 of 5 patients' EAL had its strongest cytolytic activity against an autologous tumor when the EAL was cultured with IL-2 plus IL-18, as compared with the other 4 patients whose EAL cytolytic activity against autologous tumor was highest when using IL-2 plus alpha CD3. These findings suggest that IL-18 alone did not have a significant effect on EAL, and that IL-18 did not enhance alpha CD3's activity on EAL. However, its additive effect with IL-12 in the Th-1 pathway and with IL-2 in its cytolytic activity against an autologous tumor deserve further studies.

Pleural effusion and serum soluble fas-ligand levels are elevated in different clinical conditions

Fas ligand (FasL) plays an important role in the regulation of apoptosis. Soluble FasL (sFasL) is produced by a cleavage of FasL from the cell surface by metalloproteinase. Whether or not sFasL exists or is elevated in the pleural effusion of different etiologies is unknown. The present study is designed to determine pleural effusion and serum sFasL levels under different clinical conditions, and ascertain if there exists a significant difference in the levels found in different clinical conditions, and whether this difference can be used as a tool for differential diagnosis. Soluble FasL levels in the pleural effusion and serum of 103 patients, including 37 with malignant pleural effusion, 24 with uncomplicated parapneumonic effusion, 8 with bacterial empyema, 16 with tuberculous pleurisy, and 18 with transudate effusion (8 with congestive heart failure and 10 with viral liver cirrhosis), were analyzed with ELISA assays. Pleural effusion from patients with bacterial empyema (median 79.4 pg/ml) and TB pleurisy (median 31.9 pg/ml) contained significantly higher amounts of sFasL than the pleural effusion from all other conditions studied (p <0.001). Viral liver cirrhosis had a significantly higher serum sFasL level (median 53.6 pg/ml, p = 0.025, when compared with other patients). Patients with congestive heart failure had the lowest serum sFasL levels when compared with other patients (p = 0.014). There was no significant correlation between pleural effusion sFasL levels and other parameters, such as effusion LDH, cell count, neutrophil, and lymphocyte percentage. In conclusion, soluble FasL is a useful marker for the differentiation of bacterial empyema and TB pleurisy from other disease entities. In addition, the elevation of serum sFasL levels in viral liver cirrhosis can also be used to differentiate cirrhosis from congestive heart failure, in which both effusions are transudate.

A model for the study of cystic endometrial hyperplasia in bitches

The aims of this study were: (i) to establish a reliable model for the study of cystic endometrial hyperplasia in ovariectomized bitches; and (ii) to assess the roles of oestrogen and progesterone in the pathogenesis of irritant-induced cystic endometrial hyperplasia. Greyhound bitches (n = 15) were ovariectomized and divided into five groups (n = 3 per group). After 3-4 weeks, oestradiol benzoate (0.6-4.8 micrograms kg-1, i.m.) was administered twice a day for 12 days to the bitches in group 1, followed by progesterone (0.2-1.8 mg kg-1, i.m.) twice a day for 30-33 days. These dosages were chosen to mimic the plasma hormone concentrations of a normal oestrous cycle. A silk suture was inserted by laparotomy into the left uterine horn 12 days into the simulated dioestrus (determined by vaginal cytology) and necropsy was performed after a further 12 days. For groups 2-5, the silk suture was positioned at ovariectomy. After a further 3-4 weeks, these bitches were treated with progesterone (group 2: 1.8 mg kg-1 i.m. twice a day), oestradiol benzoate (group 3: 0.6-4.8 micrograms kg-1 i.m. twice a day), oestradiol benzoate and progesterone together (group 4: previous dosages) or vehicle (group 5). Necropsies were performed after 12-13 days of treatment. Cystic endometrial hyperplasia was induced in the suture-containing uterine horns of all bitches in groups 1 and 4, and in two bitches in group 2. Cystic endometrial hyperplasia did not develop in any control (no suture) uterine horns, or in either uterine horn of the bitches treated with either oestradiol only or vehicle. These results indicate that progesterone is necessary for the development of irritant-induced cystic endometrial hyperplasia and that oestradiol potentiates the effects of progesterone. The protocol used for bitches in group 1 would be a suitable model for further studies of the pathogenesis of cystic endometrial hyperplasia.

Gemcitabine and cisplatin in a multimodality treatment for locally advanced non-small cell lung cancer

The role of new cytotoxic agents like gemcitabine has not yet been proven in the neoadjuvant settings. We designed a phase II study to test the feasibility of using gemcitabine and cisplatin before local treatment for stage III non-small cell lung cancer patients. Patients received three cycles of induction chemotherapy of gemcitabine (1000 mg m(-2), days 1, 8, 15) and cisplatin (90 mg m(-2), day 15) every 4 weeks before evaluation for operability. Operable patients underwent radical resection. Inoperable patients and patients who had incomplete resection received concurrent chemoradiotherapy with daily low dose cisplatin. All patients who did not progress after local treatment received three more cycles of adjuvant chemotherapy of gemcitabine and cisplatin. Fifty-two patients received induction treatment. Two patients had complete response and 31 patients had partial response (response rate 63.5%) after induction chemotherapy. Thirty-six patients (69%) were operable. Eighteen patients (35%) had their tumours completely resected. Two patients had pathological complete response. Median overall survival was 19.1 months, projected 1-year survival was 66% and 2-year survival was 34%. Three cycles of gemcitabine and cisplatin is effective and can be used as induction treatment before surgery for locally advanced non-small cell lung cancer patients.

Paclitaxel plus carboplatin, compared with paclitaxel plus gemcitabine, shows similar efficacy while more cost-effective: a randomized phase II study of combination chemotherapy against inoperable non-small-cell lung cancer previously untreated

BACKGROUND

Paclitaxel (Taxol) plus carboplatin (PC) has shown activity in the treatment of advanced non-small-cell lung cancer (NSCLC). Non-platinum-containing combination chemotherapy, such as paclitaxel plus gemcitabine (PG), has also demonstrated reasonable efficacy. Our aim here was to evaluate the clinical efficacy and cost-effectiveness of PC versus PG in chemo-naive. advanced NSCLC patients.

PATIENTS AND METHODS

Ninety (68 male, 22 female) patients were enrolled from August 1999 to August 2000. The performance status was one in 29 patients and two in 16 patients of the PC group, and one in 24 patients and two in 21 patients of the PG group. Seventeen patients had stage IIIb disease and 28 patients stage IV disease in the PC group: 18 patients had stage IIIb disease and 27 patients stage IV disease in the PG group (New International Staging System). Treatment consisted of P 175 mg/m2 and C at AUC = 7 (predicted using measured clearances and the Calvert formula) intravenous infusion (i.v.) on day 1, or P 175 mg/m2 i.v. on day 1 and G 1000 mg/m2 i.v. on days 1 and 8, every 3 weeks.

RESULTS

In all, 175 cycles of PC and 184 cycles of PG were given in the PC and PG groups, respectively. The median treatment cycle was four cycles in both groups. All the patients were assessable for toxicity and response measurement. There were three complete responses and 15 partial responses (overall 40%) in the PC group, and no complete response, but 18 partial responses (overall 40%) in the PG group. WHO grades 3/4 leukopenia, anemia and thrombocytopenia occurred in six (13.3%), seven (15.5%) and five patients (11.1%) in the PC group; and in four (8.9%), six (13.3%) and 0 patients in the PG group, respectively. Two patients in each group suffered from grade 3 peripheral neuropathy. Other non-hematological toxicities were mild and few. Median survival time was 14.1 months in the PC group and 12.6 months in the PG group. One-year survival was 50.7% in the PC group and 53.3% in the PG group. The PG group had a higher total expense and expended more days undergoing treatment than the PC group (P = 0.034 and 0.069, respectively).

CONCLUSIONS

Both PC and PG combination chemotherapy produce a similar efficacy in the treatment of NSCLC. However, PC is more cost-effective than PG.

Association between simple anthropometric indices and cardiovascular risk factors

OBJECTIVE

To identify which of the three simple anthropometric indices, body mass index (BMI), waist-to-hip ratio (WHR) and waist circumference (WC), best predicts cardiovascular risk factors, and to determine if the association between the anthropometric indices and cardiovascular risk factors varies with gender.

DESIGN AND METHODOLOGY

A cross-sectional population-based survey was carried out during 1995-1996. One thousand and ten Chinese people (500 men and 510 women) aged 25-74 y were recruited as subjects for the study. Metabolic profiles and anthropometric indices were measured.

RESULTS

Partial correlation and co-variance analyses showed that WC exhibited the highest degree of association with almost all of the studied metabolic profiles for both men and women. We observed significant gender differences in the association between central or general obesity with cardiovascular risk factors. BMI had an independent and significant association with metabolic risks in men, but not in women, whereas WHR was more strongly correlated with metabolic risks for women than for men. Logistic regression analysis further confirmed the magnitude of the association between the obesity indices and metabolic risks. Among the studied metabolic variables, serum insulin showed the highest degree of association with the obesity indices, followed by plasma glucose, triglyceride, HDL and blood pressure. Total cholesterol and LDL-cholesterol had a small but significant correlation with obesity. No threshold values in the relation between either the anthropometric indices and metabolic values, or with hypertension, diabetes and dislipidemia were observed.

CONCLUSION

The association of central or general obesity and metabolic syndrome varied with gender. In addition, the useful anthropometric predictors for cardiovascular risk factors were BMI and WC for men, and WC and WHR for women.

Influence of substrate exposure history on biodegradation in a porous medium

This study investigates the influence of fluctuating toluene concentrations on aerobic toluene degradation in a sandy porous medium colonized with Ralstonia pickettii PKO1. Column effluent toluene concentrations were found to increase after a temporary decrease in influent toluene concentration. Subsequent examination of the spatial gradient of toluene degradative activity in the column suggested that the observed increase in effluent toluene concentrations was attributable to an adverse effect of toluene limitation on the biodegradative activity of attached cells. The traditional Michaelis-Menten-type biodegradation equation associated with batch-measured Vmax (2.26 mg toluene/mg living cell/day) and KS (1.20 mg toluene/1) of nonstarved cells was unable to predict the observed toluene breakthrough behavior when the column had been previously exposed to no-toluene conditions. An alternative modeling approach was developed based upon the assumptions that (i) degradative activity was completely deactivated within the no-toluene exposure period (53.5 h) and (ii) a lag-phase was present prior to the subsequent reactivation of degradative activity in previously toluene-starved cells. These assumptions were independently verified by batch microbial investigations, and the modified model provided a good fit to the same observed toluene breakthrough curve. Application of single lag-time and threshold concentration values, however, failed to predict observed toluene breakthrough under different toluene exposure conditions. Results of this experimental and modeling investigation suggested that substrate exposure history, including the length of the starvation period and the level of substrate concentration, affected the induction of biodegradation in the porous medium.

Expression and localization of human dopamine D2 and D4 receptor mRNA in the adrenal gland, aldosterone-producing adenoma, and pheochromocytoma

Aldosterone secretion is evidently regulated by a dopaminergic inhibitory mechanism. Pharmacological characterization and autoradiographic studies revealed D2-like receptors in the adrenal cortex, especially in the zona glomerulosa. However, the subtype of the dopamine receptors involving this regulation has not been elucidated. To investigate which subtype of receptors expresses in the adrenal cortex, we examined the messages of D2-like receptors, D2, D3, and D4, by RT-PCR and in situ hybridization of adrenal glands and adrenal neoplasm. Both D2 and D4 receptors were expressed in normal adrenal glands, pheochromocytoma, and aldosterone-producing adenoma. However, the D2 receptors were not universally expressed, in contrast with the D4 receptors that were detected in all cases of aldosterone-producing adenoma and adrenal remnant. No D3 receptor message was detected by RT-PCR in any adrenal sample. Both D2 and D4 receptors were expressed in significant amounts in the adrenal medulla and pheochromocytoma. In the adrenal cortex, the expression of the D2 receptors was in the zona glomerulosa and zona reticularis, with no different signal intensities between the two zones. D4 receptors were mainly localized in the zona glomerulosa and, to a lesser extent, in the zona reticularis. Both receptors were expressed at low levels in the zona fasciculata. In aldosterone-producing adenoma, the expression of D2 and D4 was especially found in nonzona fasciculata-like cells. To elucidate which dopamine receptor regulates aldosterone secretion, the effects of specific D2 and D4 antagonists, raclopride and clozapine, respectively, were examined in cultured NCI-H295 cells. Dopamine further increased angiotensin II-induced aldosterone secretion by 20%. In the presence of 1 microM dopamine and angiotensin II, 10(-5)-10(-7) M clozapine decreased aldosterone levels by 40-55%. The decrease in aldosterone secretion by clozapine was completely reversed when raclopride was added simultaneously. These data suggest that dopamine exerts dual effects on aldosterone secretion in NCI-H295 cells. Activation of D4 receptors can increase aldosterone secretion, whereas an inhibitory effect is mediated via D2 receptors. In summary, we demonstrated the existence of both D2 and D4 receptors in the human adrenal gland and adrenal neoplasm. Both receptors play significant roles in the modulation of aldosterone secretion, but in opposite directions.

Klebsiella pneumoniae psoas abscess: predominance in diabetic patients and grave prognosis in gas-forming cases

Seven cases of psoas abscess caused by Klebsiella pneumoniae were observed at the National Cheng Kung University Hospital within a period of 4.5 years. These cases constituted 25% of a total 28 episodes of non-tuberculous psoas abscess, ranking second to those caused by Staphylococcus aureus (8 cases). Eight cases of psoas abscess caused by K. pneumoniae were identified from Medline, and 5 of which were reported from Taiwan. Of these 8 cases, 1 neonatal case was excluded, and the remaining 7 adult cases were combined with the 7 cases in this series for analysis. The mean age was 53.8 years, and diabetes mellitus was the most common underlying disease. Fever and pain on the flank and back area were the common findings. The interval between the onset of symptoms and diagnosis ranged from 1 to 60 days. The most common sites of concurrent infection were the urinary tract (6 cases; 43%) and bone (3 cases; 21%). All patients received percutaneous or surgical drainage in addition to antibiotic treatment. Gas formation was present in 5 of the 12 patients recorded, and 4 of them died during hospitalization. Only 1 patient had a metastatic infection with osteomyelitis of the left radius and right humerus; he had experienced 5 episodes of recurrent K. pneumoniae infections in different sites. We concluded that K. pneumoniae should be considered as an important endemic pathogen of psoas abscess in diabetics in Taiwan. The high mortality rate in the gas-forming cases should also be highlighted. Early recognition, empiric antimicrobial coverage for K. pneumoniae, and aggressive drainage or debridement are indicated in these patients.

Preoperative diagnosis and localization of aldosterone-producing adenoma by adrenal venous sampling after administration of metoclopramide

BACKGROUND AND PURPOSE

Adrenal venous sampling is the most reliable test to distinguish aldosterone-producing adenoma (APA) from idiopathic hyperaldosteronism (IHA). The diagnostic accuracy can be improved by administration of adrenocorticotropin to minimize pulsatile secretion of aldosterone. Metoclopramide (MCP), a dopamine antagonist, can increase aldosterone secretion promptly without affecting cortisol secretion. This study investigated the diagnostic accuracy of adrenal venous sampling after MCP injection for the preoperative diagnosis and localization of APA.

METHODS

Prospective diagnosis and adrenalectomy was based on adrenal venous sampling in 23 patients with a diagnosis of primary aldosteronism. Plasma aldosterone concentrations from adrenal veins and the inferior vena cava were measured before and 30 minutes after intravenous administration of 10 mg MCP. The ratio of bilateral adrenal venous aldosterone concentrations after MCP was used for diagnosis as follows: a ratio greater than 5 indicated APA, less than 3 indicated IHA, and 3-5 indicated an intermediate diagnosis.

RESULTS

Catheterization of the right adrenal vein was unsuccessful in three patients. Twelve of 13 patients with an aldosterone ratio greater than 5 after MCP underwent unilateral adrenalectomy, and APA was confirmed in 11 of these patients. One patient with an intermediate diagnosis also had surgically confirmed APA. Six patients had a ratio less than 3. Before MCP administration, 10 of 13 patients with APA had a ratio greater than 5, and three patients had a ratio between 3 and 5; one patient with IHA had a ratio greater than 5. MCP improved the diagnosis of APA to an accuracy of 92% (12/13). Correct diagnosis of APA based on computerized tomography (CT) was 85% (11/13). There was discordance between the findings of adrenal venous sampling and CT in four of 20 patients.

CONCLUSIONS

Administration of MCP to stimulate aldosterone secretion during adrenal venous sampling can improve the accuracy of differential diagnosis between APA and IHA.

Structure-function analysis of a phage display-derived peptide that binds to insulin-like growth factor binding protein 1

Highly structured, peptide antagonists of the interaction between insulin-like growth factor 1 (IGF-I) and IGF binding protein 1 (IGFBP-1) have recently been discovered by phage display of naïve peptide libraries [Lowman, H. B., et al. (1998) Biochemistry 37, 8870--8878]. We now report a detailed analysis of the features of this turn-helix peptide motif that are necessary for IGFBP-1 binding and structural integrity. Further rounds of phage randomization indicate the importance of residues contributing to a hydrophobic patch on one face of the helix. Alanine-scanning substitutions confirm that the hydrophobic residues are necessary for binding. However, structural analysis by NMR spectroscopy indicates that some of these analogues are less well folded. Structured, high-affinity analogues that lack the disulfide bond were prepared by introducing a covalent constraint between side chains at positions i and i + 7 or i + 8 within the helix. Analogues based on this scaffold demonstrate that a helical conformation is present in the bound state, and that hydrophobic side chains in this helix, and residues immediately preceding it, interact with IGFBP-1. By comparison of alanine scanning data for IGF-I and the turn-helix peptide, we propose a model for common surface features of these molecules that recognize IGFBP-1.

Interleukin-7 and interleukin-12 have different effects in rescue of depressed cellular immunity: comparison of malignant and tuberculous pleural effusions

The present study attempts to determine the role of interleukin-7 (IL-7) and IL-12 in recovering the functions of the lymphocytes of malignant effusion, in terms of cytokine production, proliferation, and cytolytic activity, compared with lymphocytes from tuberculous pleural effusion. Effusion-associated lymphocytes (EAL) were isolated from tuberculous (tEAL) and malignant (mEAL) pleural effusions. The EAL proliferate response was measured after 3 days in culture. Interferon-gamma (IFN-gamma) production and cytotoxicity against K-562 cells or autologous tumor cells were assessed after 6 days in culture. It was found that the mEAL had depressed proliferation, IFN-gamma production, and cytolytic activity, as compared with tEAL. Stimulation with IL-12 plus IL-2, but not with IL-7 plus IL-2, fully restored the IFN-gamma production of mEAL to that of tEAL levels. In contrast, the proliferate response of mEAL was enhanced significantly more with IL-7 plus IL-2 than with IL-12 plus IL-2. Both the IL-7 plus IL-2 and IL-12 plus IL-2 stimulation of mEAL showed a significant increase in cytolytic activity against autologous tumor cells, although the cytolytic activity against K-562 cells did not increase. These results suggest that tEAL had a higher cellular activity than mEAL. This depressed cellular function of mEAL could be reversed with cytokines. However, different cytokines had different effects on mEAL; for example, IL-7 had a better effect in the stimulation of lymphocyte proliferation compared with IL-12, which had a better effect in driving the lymphocytes to the T helper 1 (TH1) pathway and a higher IFN-gamma production. Both IL-7 and IL-12, in the presence of IL-2, can restore the immunosuppressed cytolytic activity of the lymphocytes of malignant pleural effusion against autologous tumor.

Clostridium bacteremia: emphasis on the poor prognosis in cirrhotic patients

Bacteremic episodes caused by anaerobes are unusual and the clinical importance of Clostridium bacteremia remains unclear. This retrospective case study examined the risk factors among a group of patients who developed Clostridium bacteremia. Medical records from 73 episodes of clostridial bacteremia in 73 patients treated in a medical center during an 11-year period were reviewed. Of all episodes, 96% were community-acquired. Twelve percent of patients had polymicrobial bacteremia, with Escherichia coli being the most common accompanying bacterium. Diabetes mellitus (26%) and liver cirrhosis (25%) were the most common underlying diseases. The most common etiological organisms were Clostridium perfringens (77%), Clostridium bifermentans (9%), and Clostridium septicum (4%). Only one patient with C. septicum bacteremia had a histocytotoxic infection, which was a fatal gas gangrene. Univariate analysis of data from patients with monomicrobial Clostridium bacteremia revealed that younger age (age < 65 years), underlying liver cirrhosis, and presence of septic shock at initial presentation were associated with fatality; but only the latter two variables were independently associated with fatality in multivariate logistic regression analysis. Appropriate antimicrobial therapy for monomicrobial Clostridium bacteremia did not significantly affect clinical outcomes, which might suggest that Clostridium species in the bloodstream can be regarded as merely contaminants or transient bacteremia. This suggestion was not supported by the finding that seven of 13 cirrhotic patients with monomicrobial Clostridium bacteremia died of sepsis, of whom six had not receive appropriate antimicrobial therapy. Therefore, the clinical importance of Clostridium bacteremia should be interpreted with caution because of its high risk of mortality in susceptible hosts, particularly cirrhotic patients, who do not receive appropriate therapy timely.