Dedifferentiated liposarcoma: a clinicopathological analysis of 155 cases with a proposal for an expanded definition of dedifferentiation

We studied 155 cases of dedifferentiated liposarcoma to define its clinicopathologic features and behavior, in particular how the extent and grade of dedifferentiation affected outcome. Tumors occurred in late adult life (median, 61.5 years: range, 21-92 years), most commonly in the retroperitoneum (106 cases), extremities and trunk (32 cases), and scrotum/spermatic cord (13 cases). The majority of dedifferentiated liposarcomas presented as de novo lesions, whereas the remainder developed as a late complication of a preexisting well-differentiated liposarcoma after an average interval of 7.7 years. At the time of presentation, most of the dedifferentiated liposarcomas displayed extensive areas of high-grade dedifferentiation resembling malignant fibrous histiocytoma or high-grade fibrosarcoma, whereas a minority contained only areas of low-grade dedifferentiation resembling fibromatosis or well-differentiated fibrosarcoma. Divergent myosarcomatous or osteosarcomatous differentiation was observed focally in six cases. The behavior of dedifferentiated liposarcomas was that of a high-grade sarcoma with a local recurrence rate of 41%, a metastatic rate of 17%, and disease-related mortality of 28%. The most important prognostic factor was location in that retroperitoneal tumors had significantly worse survival than those in other sites. Tumors were divided into those having less than or those with more than 25% dedifferentiation, and dedifferentiated zones were classified into low grade or high grade. Neither low-grade dedifferentiation nor a low percentage of dedifferentiation was associated with an improved outcome for the tumors examined in this study; however, in no cases was the absolute size of the dedifferentiated focus <2 cm. Therefore, this study did not determine a minimum, or threshold, amount of dedifferentiation below which outcome was more favorable. The behavior of liposarcomas in which the dedifferentiated component was entirely low grade was more similar to that of traditional dedifferentiated liposarcoma than to that of well-dedifferentiated liposarcoma. Our study supports the expansion of the definition of dedifferentiated liposarcoma to include tumors with low-grade dedifferentiation and also suggests that low-grade dedifferentiation represents a precursor lesion of high-grade dedifferentiation.

Mapping the functional surface of insulin by design: structure and function of a novel A-chain analogue

Functional surfaces of a protein are often mapped by combination of X-ray crystallography and mutagenesis. Such studies of insulin have yielded paradoxical results, suggesting that the native state is inactive and reorganizes on receptor binding. Of particular interest is the N-terminal alpha-helix of the A-chain. Does this segment function as an alpha-helix or reorganize as recently proposed in a prohormone-convertase complex? To correlate structure and function, we describe a mapping strategy based on protein design. The solution structure of an engineered monomer ([AspB10, LysB28, ProB29]-human insulin) is determined at neutral pH as a template for synthesis of a novel A-chain analogue. Designed by analogy to a protein-folding intermediate, the analogue lacks the A6-A11 disulphide bridge; the cysteine residues are replaced by serine. Its solution structure is remarkable for segmental unfolding of the N-terminal A-chain alpha-helix (A1 to A8) in an otherwise native subdomain. The structure demonstrates that the overall orientation of the A and B chains is consistent with reorganization of the A-chain's N-terminal segment. Nevertheless, the analogue's low biological activity suggests that this segment, a site of clinical mutation causing diabetes mellitus, functions as a preformed recognition alpha-helix.

Cloning and expression of ZAK, a mixed lineage kinase-like protein containing a leucine-zipper and a sterile-alpha motif

A novel mixed lineage kinase-like protein ZAK, containing a leucine-zipper (LZ) and a sterile-alpha motif (SAM), was cloned. This cDNA has 2456 bp and encodes a protein of 800 amino acids that contains a kinase catalytic domain, a leucine-zipper and a SAM. The molecular weight of this protein is 91kDa. Northern blot analysis revealed that the expression of this ZAK gene is found in various parts of human tissues. We also found that ZAK proteins might form homodimers or oligomers in mammalian cells. MLKs have been proposed to function as mitogen-activated protein kinase kinase kinase in pathways leading to MAPK cascade. The expression of ZAK in mammalian cells specifically leads to the activation of the JNK/SAPK pathway as well as the activation of transcription factor, NF-kappaB. Overexpression of the ZAK gene induces the apoptosis of a hepatoma cell line.

Terbutaline inhalation suppresses fentanyl-induced coughing

PURPOSE

To study the suppressive effect of inhalation of a selective beta 2-adrenergic bronchodilator terbutaline, and the effect of an intravenous anticholinergic, atropine, on fentanyl-induced coughing.

METHODS

We studied 131 ASA class I patients, aged 16-45 yr, scheduled for elective surgery, randomized into four groups. Fifteen minutes before bolus fentanyl (5 micrograms.kg-1, iv), patients inhaled either normal saline (4 ml; Group I, n = 30) or terbutaline (5 mg in 2 ml normal saline; Group 2, n = 34) via a jet nebulizer. After inhalation of normal saline, patients in Group 3 (n = 32) received sterile water iv instead of fentanyl. Patients in Group 4 (n = 35) were pretreated with atropine (0.01 mg.kg-1, iv) 10 min before iv fentanyl bolus. The onset, frequency and intensity of cough were observed immediately by an anaesthetist blinded to the study.

RESULTS

The cough frequency was higher in Groups I (43%) and 4 (46%) than in Groups 2 (3%) and 3 (0%) (P < 0.05). The onset time and intensity of cough showed no difference among groups. No truncal rigidity was observed in patients receiving fentanyl bolus iv. The blood pressure, heart rate, and peripheral oxygen saturation did not change in Groups 1, 2, and 3, while patients in Group 4 showed an increase in heart rate (25.5 +/- 15.2%).

CONCLUSIONS

The inhalation of a selective beta 2-adrenergic bronchodilator, terbutaline, effectively inhibited fentanyl-induced cough, whereas atropine, an antimuscarinic vagolytic, had no efficacy. Our results suggest that bronchoconstriction may underlie the mechanism on fentanyl-induced cough.

Hierarchical protein folding: asymmetric unfolding of an insulin analogue lacking the A7-B7 interchain disulfide bridge

The landscape paradigm of protein folding can enable preferred pathways on a funnel-like energy surface. Hierarchical preferences may be manifest as a nonrandom pathway of disulfide pairing. Stepwise stabilization of structural subdomains among on-pathway intermediates is proposed to underlie the disulfide pathway of proinsulin and related molecules. Here, effects of pairwise serine substitution of insulin's exposed interchain disulfide bridge (Cys(A7)-Cys(B7)) are characterized as a model of a late intermediate. Untethering cystine A7-B7 in an engineered monomer causes significantly more marked decreases in the thermodynamic stability and extent of folding than occur on pairwise substitution of internal cystine A6-A11 [Weiss, M. A., Hua, Q. X., Jia, W., Chu, Y. C., Wang, R. Y., and Katsoyannis, P. G. (2000) Biochemistry 39, 15429-15440]. Although substantially disordered and without significant biological activity, the untethered analogue contains a molten subdomain comprising cystine A20-B19 and a native-like cluster of hydrophobic side chains. Remarkably, A and B chains make unequal contributions to this folded moiety; the B chain retains native-like supersecondary structure, whereas the A chain is largely disordered. These observations suggest that the B subdomain provides a template to guide folding of the A chain. Stepwise organization of insulin-like molecules supports a hierarchic view of protein folding.

Specific induction of glutathione S-transferase GSTM2 subunit expression by epigallocatechin gallate in rat liver

The antitumor effect of green tea polyphenols has been well characterized in numerous papers. However, the mechanism of their action is still poorly defined. In this study, epigallocatechin gallate (EGCG), the main ingredient of green tea extract, was studied for its effect on the expression of glutathione S-transferases (GSTs) in rat liver to examine the mechanism of action. Liver samples were collected from Sprague-Dawley rats treated with EGCG in H(2)O by portal vein perfusion and examined for total GST activity and GST expression. The results showed that the induction of GST activity by EGCG was dose- and time-dependent. GST activity was increased about 28-fold at 12 hr after treatment. Three GST subunits (GSTA1/2, GSTM1, and GSTM2) were examined by Western blot for changes in protein level affected by EGCG (1 mg/kg weight). Only GSTM2 revealed a significant time-dependent increase, with a maximal induction of approximately 2.0-fold. The differential effect of EGCG on GST subunit expression was also verified by immunocytochemical examination and showed strong induction of the GSTM2 (but not the GSTA1/2 and GSTM1) level in liver section. This induction occurred as early as 3 hr after treatment and extended gradually outward from the hepatic veins as treatment time increased. The change in the GSTM2 protein level was accompanied by a corresponding alteration in mRNA quantity ( approximately 2.0-fold of control). Our report is the first to demonstrate a specific induction of the GSTM2 subunit by a chemopreventor and suggests a primary influence of EGCG on GSTM2 gene expression.

Hierarchical protein "un-design": insulin's intrachain disulfide bridge tethers a recognition alpha-helix

A hierarchical pathway of protein folding can enable segmental unfolding by design. A monomeric insulin analogue containing pairwise substitution of internal A6-A11 cystine with serine [[Ser(A6),Ser(A11),Asp(B10),Lys(B28),Pro(B29)]insulin (DKP[A6-A11](Ser))] was previously investigated as a model of an oxidative protein-folding intermediate [Hua, Q. X., et al. (1996) J. Mol. Biol. 264, 390-403]. Its structure exhibits local unfolding of an adjoining amphipathic alpha-helix (residues A1-A8), leading to a 2000-fold reduction in activity. Such severe loss of function, unusual among mutant insulins, is proposed to reflect the cost of induced fit: receptor-directed restoration of the alpha-helix and its engagement in the hormone's hydrophobic core. To test this hypothesis, we have synthesized and characterized the corresponding alanine analogue [[Ala(A6),Ala(A11),Asp(B10),Lys(B28), Pro(B29)]insulin (DKP[A6-A11](Ala))]. Untethering the A6-A11 disulfide bridge by either amino acid causes similar perturbations in structure and dynamics as probed by circular dichroism and (1)H NMR spectroscopy. The analogues also exhibit similar decrements in thermodynamic stability relative to that of the parent monomer as probed by equilibrium denaturation studies (Delta Delta G(u) = 3.0 +/- 0.5 kcal/mol). Despite such similarities, the alanine analogue is 50 times more active than the serine analogue. Enhanced receptor binding (Delta Delta G = 2.2 kcal/mol) is in accord with alanine's greater helical propensity and more favorable hydrophobic-transfer free energy. The success of an induced-fit model highlights the applicability of general folding principles to a complex binding process. Comparison of DKP[A6-A11](Ser) and DKP[A6-A11](Ala) supports the hypothesis that the native A1-A8 alpha-helix functions as a preformed recognition element tethered by insulin's intrachain disulfide bridge. Segmental unfolding by design provides a novel approach to dissecting structure-activity relationships.

Mini-proinsulin and mini-IGF-I: homologous protein sequences encoding non-homologous structures

Protein minimization highlights essential determinants of structure and function. Minimal models of proinsulin and insulin-like growth factor I contain homologous A and B domains as single-chain analogues. Such models (designated mini-proinsulin and mini-IGF-I) have attracted wide interest due to their native foldability but complete absence of biological activity. The crystal structure of mini-proinsulin, determined as a T3R3 hexamer, is similar to that of the native insulin hexamer. Here, we describe the solution structure of a monomeric mini-proinsulin under physiologic conditions and compare this structure to that of the corresponding two-chain analogue. The two proteins each contain substitutions in the B-chain (HisB10-->Asp and ProB28-->Asp) designed to destabilize self-association by electrostatic repulsion; the proteins differ by the presence or absence of a peptide bond between LysB29 and GlyA1. The structures are essentially identical, resembling in each case the T-state crystallographic protomer. Differences are observed near the site of cross-linking: the adjoining A1-A8 alpha-helix (variable among crystal structures) is less well-ordered in mini-proinsulin than in the two-chain variant. The single-chain analogue is not completely inactive: its affinity for the insulin receptor is 1500-fold lower than that of the two-chain analogue. Moreover, at saturating concentrations mini-proinsulin retains the ability to stimulate lipogenesis in adipocytes (native biological potency). These results suggest that a change in the conformation of insulin, as tethered by the B29-A1 peptide bond, optimizes affinity but is not integral to the mechanism of transmembrane signaling. Surprisingly, the tertiary structure of mini-proinsulin differs from that of mini-IGF-I (main-chain rms deviation 4.5 A) despite strict conservation of non-polar residues in their respective hydrophobic cores (side-chain rms deviation 4.9 A). Three-dimensional profile scores suggest that the two structures each provide acceptable templates for threading of insulin-like sequences. Mini-proinsulin and mini-IGF-I thus provide examples of homologous protein sequences encoding non-homologous structures.

Anaplastic large cell Ki-1 lymphoma involving bone marrow: marrow findings and association with reactive hemophagocytosis

This report describes the bone marrow findings in four patients whose marrow was involved by anaplastic large-cell Ki-1 lymphoma, an uncommon event in this type of lymphoma. In the marrow aspirate smears, the involvement was subtle, and was in the form of isolated large cells with irregular nuclear configuration, coarse chromatin, prominent nucleoli, and basophilic cytoplasm which might be vacuolated. One case showed paradoxically massive involvement in the trephine biopsy taken from the same site as the marrow aspirate. Reactive histiocytic proliferation with hemophagocytosis was also present. Since marrow aspirate or biopsy may be the first pathologic specimen examined in patients having anaplastic large-cell Ki-1 lymphoma, it is important to be able to recognize the small population of neoplastic cells, which should lead to prompt treatment or further investigations as deemed necessary.

Metastatic renal cell carcinoma in a meningioma: a case report

Tumor-to-tumor metastasis is rare. We report a case of metastatic renal cell carcinoma in meningioma. A 67-year-old woman presented a two-week history of motor dysphagia and decreased short-term memory. She had undergone a left radical nephrectomy for a renal cell carcinoma 7 years ago, and had not received any adjuvant therapy. MRI disclosed a 3.0 x 3.0 x 3.0-cm sized round tentorial-based extraaxial mass with peritumoral edema in the left posterior temporal lobe. During operation, the tumor was found to be an encapsulated mass firmly attached to the tentorium. Histologically, the tumor was a meningotheliomatous meningioma extensively infiltrated by metastatic renal cell carcinoma, accompanying widespread coagulative necrosis. Immunohistochemical staining for cytokeratin revealed strong positivity only in the renal cell carcinoma component. The patient's postoperative course was uneventful. Post-operative radiation therapy was applied to the whole brain. Three months after operation, the patient developed right hemiparesis and dysphagia. Brain MRI at that time did not reveal recurrence or any other causative lesions, although the whole body scan disclosed uptake at the second lumbar vertebra and rib. The patient refused further treatment.

Pure red cell aplasia: clinical features and treatment results in 16 cases

Pure red cell aplasia (PRCA) is a rare hematological disease characterized by selective marrow erythroid aplasia. We report the clinical features and treatment results of 16 Chinese patients with PRCA. Nine (56%) cases were not associated with any underlying disorders and were considered idiopathic, while seven patients (44%) had associated diseases, three involving the thymus, two with T large granular lymphocyte leukemia (T-LGLL), and one each with Stevens-Johnson syndrome and acute hepatitis A. Conventional-dose corticosteroid therapy resulted in complete remission in three of 13 patients. Cyclosporin A was used in six patients. There were three complete and one partial remissions. High-dose methylprednisolone was ineffective in four patients who failed conventional-dose corticosteroids but achieved complete remission in one patient with thymoma who did not respond to thymectomy. Antithymocyte globulin was used in four patients, resulting in partial remission in only one patient with concomitant T-LGLL. Intravenous gamma globulin and danazol were ineffective in three patients. Thymectomy was performed in two patients, with one patient remitting. This is the largest series of PRCA reported in an oriental population. Our results indicate that treatment of PRCA may still be problematic and better therapeutic strategy will have to be defined.

Activities of monomeric insulin analogs at position A8 are uncorrelated with their thermodynamic stabilities

Previous studies have demonstrated that the potency and thermodynamic stability of human insulin are enhanced in concert by substitution of Thr(A8) by arginine or histidine. These surface substitutions stabilize the N-terminal alpha-helix of the A chain, a key element of hormone-receptor recognition. Does enhanced stability necessarily imply enhanced activity? Here, we test by structure-based mutagenesis the relationship between the stability and activity of the hormone. To circumvent confounding effects of insulin self-association, A chain analogs were combined with a variant B chain (Asp(B10), Lys(B28), and Pro(B29) (DKP)) to create a monomeric template. Five analogs were obtained by chain combination; disulfide pairing proceeded in each case with native yield. CD and (1)H NMR spectra of the DKP analogs are essentially identical to those of DKP-insulin, indicating a correspondence of structures. Receptor binding affinities were determined by competitive displacement of (125)I-insulin from human placental membranes. Thermodynamic stabilities were measured by CD titration; unfolding was monitored as a function of guanidine concentration. In this broader collection of analogs receptor binding affinities are uncorrelated with stability. We suggest that receptor binding affinities of A8 analogs reflect local features of the hormone-receptor interface rather than the stability of the free hormone or the intrinsic C-capping propensity of the A8 side chain.

Incidence and risk factors of guidewire-induced arrhythmia during internal jugular venous catheterization: comparison of marked and plain J-wires

STUDY OBJECTIVES

To compare the incidence and risk factors of guidewire-induced arrhythmia (GIA) during internal jugular venous catheterization (IJV).

DESIGN

Prospective study.

SETTING

Operating rooms at a medical center.

PATIENTS

303 ASA physical status I, II, III, and IV patients undergoing elective surgery.

INTERVENTIONS

All patients were cannulated with the central venous catheters placed via the right internal jugular vein after induction of anesthesia. They were randomly divided into two groups. In one group, we used a marked J-wire and inverted up to, but not beyond 20 cm (Group M, n = 127). In the other group, a plain unmarked J-wire was used and inserted at will (Group UM, n = 176). All IJV catheterizations were performed by residents, and the length of J-wire inserted was then measured.

MEASUREMENTS AND MAIN RESULTS

Types of arrhythmia [eg, premature atrial contraction (PAC) or premature ventricular contraction (PVC)] were interpreted by attending anesthesiologists on lead II ECG. Patients in Group UM had a significantly greater incidence of GIA than those in Group M (28.4% vs. 3.9%; p < .005). However, in both groups, PAC occurred more frequently than PVC. Factors such as the inserted length of guidewire longer than 20 cm, body height less than 170 cm, and female gender were significantly associated with GIA (p < 0.005).

CONCLUSIONS

Limiting the length of the guidewire insertion to less than or equal to 20 cm for right IJV catheterization by using a marked J-wire will reduce the incidence of GIA. We recommend the use of a marked J-wire for IJV catheterization.

Multiple XbaI polymorphisms for carrier detection and prenatal diagnosis of haemophilia A

Three XbaI restriction fragment length polymorphisms (RFLPs) can be detected using the factor VIII-intron 22 probe (p482.6) in a XbaI-KpnI double digest of genomic DNA. The XbaI (A) site had been reported by Wion et al (1986) to be in intron 22, while the two additional sites. XbaI (B) and XbaI (C), are shown here to be X-linked and close to the XbaI (A) site. The frequencies of heterozygosity for these three sites are 0.49, 0.18 and 0.30 respectively. In 75 females the observed heterozygosity rate for the XbaI (A) site is 0.41 and this increased to 0.57 with the two additional sites. Care should be exercised when interpreting the XbaI RFLPs, since the 1.4 kb XbaI/KpnI fragment and the 4.8 kb XbaI fragment are associated with both positive XbaI (A) and XbaI (B) sites. By the combined use of the multiple XbaI polymorphisms with the BclI site in intron 18, the carrier detection rate would increase to 67%. Four prenatal diagnoses had been performed using the multiple XbaI polymorphisms.

The management of isolated thrombocytopenia in Chinese adults: does bone marrow examination have a role at presentation?

We performed a retrospective analysis of bone marrow examination (BME) in the management of Chinese adult patients less than 60 years of age with isolated thrombocytopenia at presentation. Eighty-three patients with a median age of 39 years presenting with isolated thrombocytopenia (median platelet count: 38 x 10(9)/l) had routinely undergone BME as part of the laboratory investigations during the period from January 1996 to December 1999. All 83 patients had bone marrow findings of active marrow suggesting causes due to peripheral destruction. All of these patients responded to steroid or intravenous immunoglobulin (IVIg) therapy at presentation if their platelet counts were significantly low or if they had mucosal bleeding. Eighty-one of the 83 patients, after a median of 20 months follow-up, were finally diagnosed as having idiopathic thrombocytopenic purpura (ITP). The remaining two patients were finally confirmed as cases of systemic lupus erythematosus (SLE). Our results suggest that BME is not helpful in the diagnosis of isolated thrombocytopenia or suspected ITP in adult patients at presentation, provided that a thorough clinical history and physical examination are undertaken and that the blood count and peripheral blood smear show no abnormalities apart from the thrombocytopenia.

Large cell lymphoma with initial presentation in the bone marrow

This report describes 14 cases of large cell lymphoma with initial presentation as marrow involvement in the absence of peripheral lymphadenopathy. The disease affected mainly the middle-aged and elderly, with male predominance. Most patients presented with swinging fever and peripheral blood cytopenia. Reactive hemophagocytic syndrome was a common finding, causing significant morbidity and mortality. Peripheral lymphadenopathy was absent (by case selection), but involvement of the liver, spleen and paraaortic lymph nodes could be demonstrated in some cases. However, in some patients, the involvement was apparently restricted to the bone marrow. Involvement of the bone marrow was often subtle, and could be missed on causal examination. Immunohistochemical studies on eight cases showed that four exhibited a B-cell phenotype, three a T-cell phenotype and one a non-T non-B phenotype. The prognosis was poor, with survival being measured in days to weeks in most patients.

S-100 protein-positive sinusoidal large cell lymphoma

A subset of T lymphocytes has recently been reported to express S-100 protein. We report a case of S-100-positive peripheral T-cell lymphoma with a sinusoidal pattern of lymph node involvement. The immunophenotypic profile was T1+, T3+, T4+, T6-, T8-, T11+. The 12-year-old boy presented with thrombocytopenia and splenomegaly and was found to have malignant lymphoma involving the para-aortic lymph nodes, spleen, and bone marrow. The disease ran a rapidly fatal course.

Myositis ossificans of the chest wall simulating malignant neoplasm

Myositis ossificans originating from the chest wall is extremely rare. We report a case of myositis ossificans occurring in a young woman with progressive painful swelling in the chest wall. Preoperative examination suggested a malignant neoplasm originating from soft tissue. Although rare, myositis ossificans is one of the potential causes of painful swelling in the chest wall, and can be mistaken for a malignant neoplasm.

Churg-Strauss syndrome with perforating ulcers of the colon

We report a case of a 72-year-old woman with Churg-Strauss syndrome, who presented with intestinal perforation. She has had bronchial asthma with peripheral blood eosinophilia for 30 years. Gross findings of a resected colon showed multiple ulcers with perforation. Histologic findings demonstrated transmural inflammation infiltrated with large numbers of eosionophils, neutrophils and lymphoplasma cells, and characteristic extravascular granuloma in the subserosa. There were multifocally-distributed transmural vasculitis showing all stages of activity in medium and small-sized arteries and veins located in the submucosa, and proper muscle and subserosal layers of the colon, some of which revealed granulomatous inflammation. Histologic finding of liver showed chronic viral hepatitis B with mild inflammatory activity and macronodular cirrhosis. Immunohistochemical findings, acid fuschin orange G staining and electromicroscope found no evidence of hepatitis B virus infection contributing to the pathogenesis of this lesion.

All-trans retinoic acid (ATRA) in the treatment of acute promyelocytic leukemia (APL)

Acute promyelocytic leukemia is characterized by the reciprocal translocation of chromosomes 15 and 17. All-trans retinoic acid (ATRA) efficiently induces differentiation of the abnormal promyelocytes. In this study, we had used ATRA as the primary induction therapy for 17 newly diagnosed patients, and as the salvage therapy for 11 patients who relapsed from or were resistant to chemotherapy. All patients received subsequent consolidation chemotherapy. Complete remission (CR) rate, early death rate (within 28 days of diagnosis) were then compared to an historical control of 50 APL patients treated with combination chemotherapy; and event-free survival of the 17 newly diagnosed patients was compared to the historical control. In the ATRA group, 26 of the 28 patients (93 per cent) attained complete remission. Two of 28 (7 per cent) died within 28 days of ATRA therapy. There was no case of primary resistance to ATRA. Combination chemotherapy was added to ATRA in five patients due to rapidly increasing leucocyte count. There was one case of retinoic acid syndrome which resolved with steroid. When compared to the 50 cases of historical control, there is significant improvement in the overall CR rate (92 per cent versus 59 per cent, p = 0.001) and a significant reduction in the early mortality rate (7 per cent versus 41 per cent, p = 0.001). Moreover, when the survival result of the 17 newly diagnosed patients were compared with the control, there is a significant improvement in the projected EFS at 3 years (64 per cent versus 25 per cent, p = 0.007). In conclusion, ATRA was shown to improve the CR rate, reduce induction mortality and significantly prolong the event-free survival.

5-Hydroxytryptophan: an absorption and fluorescence probe which is a conservative replacement for [A14 tyrosine] in insulin

Use of insulin's intrinsic tyrosine absorption and fluorescence to monitor its interaction with the insulin receptor is limited because the spectral properties of the receptor tryptophan residues mask the spectral properties of the hormone tyrosine residues. We describe the synthesis of an insulin analog where A14 tyrosine is replaced by a tryptophan analog, 5-hydroxytryptophan. This insulin is spectrally enhanced since 5-hydroxytryptophan has an absorption band above 300 nm which is at lower energies than the absorption of tryptophan. Steady-state and time-resolved fluorescence parameters indicate that 5-hydroxytryptophan reports the same information about the environment of the A14 side chain as does the corresponding tryptophan-containing insulin. The synthetic hormone is a full agonist compared to porcine insulin, but has slightly reduced specific activity. Consequently, this spectrally enhanced insulin analog will be useful for hormone-receptor interaction studies since it can be observed by both absorption and fluorescence even in the presence of the tryptophan-containing receptor.

Pathologic study of mice infected with Rickettsia tsutsugamushi R19 strain

Scrub typhus, an acute febrile infectious disease caused by R. tsutsugamushi, has been reported from various parts of the far east and pacific rim of Asia including Korea. It is well known that all human pathogenic rickettsia share an affinity to endothelial cells of the small blood vessels and evoke vascular inflammation variably associated with a rash, microthrombi, and hemorrhage. We infected the ICR mice by inoculating sublethal doses of R. tsutsugamushi R19 strain intraperitoneally and observed the pathologic changes by time sequence. The histopathologic features of experimentally induced scrub typhus in the mice were generally nonspecific interstitial inflammations characterized by interstitial pneumonitis, periportal inflammation, multifocal hepatic necrosis, interstitial nephritis, sinusoidal engorgement, and lymphohistiocytic cell infiltration in lymph nodes and spleen. Contrary to the general features of other rickettsial diseases, the pathologic process of scrub typhus experimentally induced by R. tsutsugamushi R19 strain mainly involved the interstitial connective tissue but not the blood vessels.