Defining the anatomy of the Rangifer tarandus sex chromosomes

A comprehensive cytogenetic characterization of the unusally large reindeer (Rangifer tarandus) sex chromosomes is presented for the purpose of studying the evolution of these atypical gonosomes. Sex chromosome idiograms were constructed from G-banded and C-banded chromosomes to illustrate the relative amounts and locations of euchromatin and heterochromatin. Hybridization with a Mazama gouazoubira X whole-chromosome paint revealed that essentially all reindeer X-linked euchromatin and most reindeer Y-linked euchromatin is conserved interspecifically. Subsequently, painting probes were generated from flow-sorted reindeer X chromosomes, flow-sorted reindeer Y chromosomes, and from microdissections of specific gonosomal regions to establish specific segment-to-segment homologies between these gonosomes. In particular, one microdissection-generated paint demonstrated that certain constituent repetitive DNAs, found in C-band region Xq31, were also present in essentially all heterochromatin blocks of the Y chromosome. Microdissection-generated paints from other X-linked heterochromatin blocks revealed the presence of DNA sequences that lacked homologous sequences on the Y chromosomes and were more specific for their region of origin. These characteristics of the reindeer sex chromosomes are consistent with the notion that mammalian sex chromosomes were derived from homologous progenitor chromosome pairs and provide insights into the evolution of these atypical mammalian gonosomes.

Congenital renal arteriovenous malformations: two cases report

Congenital arteriovenous malformation (AVM) of the kidney is a rare condition. Rupture of an AVM in the kidney may cause hematuria, flank pain, and urinary retention due to clots. We report 2 cases of congenital renal AVM. Both were treated with transcatheter renal arterial embolization. The signs and symptoms disappeared after embolization. On follow-up, renal function testing with a DMSA scan revealed only focal loss of renal cortical function. The clinical courses of 2 cases are reported and the literature is reviewed.

Pharmacokinetic drug interaction study: administration of ceftibuten concurrently with the antacid mylanta double- strength liquid or with ranitidine

This study investigated the influence of antacid (Mylanta Double-Strength Liquid; J & J-Merck Consumer, Fort Washington, PA) and the H2 antagonist ranitidine on the pharmacokinetics of ceftibuten, a once-daily oral cephalosporin. Eighteen male volunteers received, in a randomized, three-way, crossover design, a single oral 400-mg dose of ceftibuten after an overnight fast (1) alone, (2) with antacid (60 mL), and (3) with ranitidine (after 3 days of dosing, 150 mg/12 hours). Serial blood and urine samples were collected during a 24-hour period after each administration, with a 1-week washout between treatments. Ceftibuten, and its metabolite ceftibuten-trans, were analyzed in plasma and urine by high-performance liquid chromatography. Bioavailability parameters, maximum plasma concentration and area under the plasma concentration-time curve to infinity of ceftibuten were unaffected by treatment with antacid. These parameters were somewhat higher when ceftibuten was administered with ranitidine, but they were still within the ranges seen in normal healthy volunteers. The excretion of ceftibuten was independent of treatment. The concentrations of ceftibuten-trans were low in both plasma and urine with all three treatments. It is concluded that the co-administration of antacid and ranitidine are unlikely to affect the bioavailability and antibacterial efficacy of ceftibuten.

Isolation of functional Golgi-derived vesicles with a possible role in retrograde transport

Secretory proteins enter the Golgi apparatus when transport vesicles fuse with the cis-side and exit in transport vesicles budding from the trans-side. Resident Golgi enzymes that have been transported in the cis-to-trans direction with the secretory flow must be recycled constantly by retrograde transport in the opposite direction. In this study, we describe the functional characterization of Golgi-derived transport vesicles that were isolated from tissue culture cells. We found that under the steady-state conditions of a living cell, a fraction of resident Golgi enzymes was found in vesicles that could be separated from cisternal membranes. These vesicles appeared to be depleted of secretory cargo. They were capable of binding to and fusion with isolated Golgi membranes, and after fusion their enzymatic contents most efficiently processed cargo that had just entered the Golgi apparatus. Those results indicate a possible role for these structures in recycling of Golgi enzymes in the Golgi stack.

Schizotypy in community samples: the three-factor structure and correlation with sustained attention

The authors examined cross-cultural applicability of the Schizotypal Personality Questionnaire (SPQ), the Perceptual Aberration Scale (PAS), and the Continuous Performance Test in community samples of Taiwanese adults and adolescents. The authors tested hypotheses that a 3-factor structure of the SPQ (Cognitive-Perceptual, Interpersonal, and Disorganization: A. Raine et al., 1994) exists for both samples and that the Interpersonal factor is associated with poorer attention. The authors replicated the 3-factor model for both samples, and they externally validated the model in adults: The Interpersonal factor and possibly the Disorganization factor were associated with poorer attention, whereas the Cognitive-Perceptual factor was not. The PAS differed from the Cognitive-Perceptual factor in its consistent association with poorer attention in both samples. These have important implications for the scales in the early detection of the schizotypy in various cultures.

Evaluation of the hepatoprotective and antioxidant activity of Boehmeria nivea var. nivea and B. nivea var. tenacissima

In this study, the relationship between liver protective effects and antioxidant activity of Boehmeria nivea var. nivea (= B. nivea) and B. nivea var. tenacissima (= B. frutescens) was investigated. The water extracts of both plants exhibited a hepatoprotective activity against CCl4-induced liver injury. B. nivea var. nivea and B. nivea var. tenacissima, also showed anti-oxidant effects in FeCl2-ascorbate induced lipid peroxidation in rat liver homogenate. Moreover, the active oxygen species scavenging potencies were evaluated by an electron spin resonance (ESR) spin-trapping technique. B. nivea var. tenacissima displayed better superoxide radical scavenging activity than B. nivea. Based on these findings, we suggest that in the liver protective and antioxidative effects of B. nivea var. nivea and B. nivea var. tenacissima, possibly involve mechanisms related to free radical scavenging effects.

Serum HDL level at acute stage of Kawasaki disease

Kawasaki disease is a disease of acute vascular inflammation of unknown etiology and HDL is a known risk factor of vascular damage. So far, there is no specific serum marker for KD. The previous study has shown a remarkable change of serum HDL in the patients with KD. To find whether changes in serum HDL level is a specific serum marker for early diagnosis of KD, we measured the concentration of HDL, LDL, TC, TG and CRP immediately after admission and one week later in three groups of patients (56 patients with KD, 38 patients with clinical viral infection, and 42 patients with bacterial infection). There was a significant decrease of HDL and increase of TG immediately after admission in three groups of patients. HDL and TG did not return to normal one week later. HDL level is more adversely affected in severe diseases than in mild diseases. Our results indicated that low HDL level is noted in various acute infection and is not a specific serum marker in the early stage of Kawasaki disease. It is interesting that low HDL is a universal phenomenon in this series. Further research is needed to explain the mechanism of lipid alterations and its consequences.

DK phocomelia phenotype (von Voss-Cherstvoy syndrome) caused by somatic mosaicism for del(13q)

DK phocomelia (von Voss-Cherstvoy syndrome) is a rare condition characterized by radial ray defects, occipital encephalocoele, and urogenital abnormalities. Lubinsky et al. [1994: Am J Med Genet 52:272-278] pointed out similarities between this and the del(13q) syndrome. To date, all reported cases of DK phocomelia have been apparently normal chromosomally. We report on a case of DK phocomelia in which the proposita had normal lymphocyte chromosomes, but was mosaic in fibroblasts for del(13)(q12). Fibroblast chromosomes studies on other cases of DK phocomelia have not been reported: this raises the possibility that some cases of DK phocomelia may be somatic mosaics for del(13)(q12).

Structure-activity relationship of 3-substituted N-(pyridinylacetyl)-4- (8-chloro-5,6-dihydro-11H-benzo[5,6]cyclohepta[1,2-b]pyridin-11-ylidene )- piperidine inhibitors of farnesyl-protein transferase: design and synthesis of in vivo active antitumor compounds

Novel tricyclic Ras farnesyl-protein transferase (FPT) inhibitors are described. A comprehensive structure-activity relationship (SAR) study of compounds arising from substitution at the 3-position of the tricyclic pyridine ring system has been explored. In the case of halogens, the chloro, bromo, and iodo analogues 19, 22, and 28 were found to be equipotent. However, the fluoro analogue 17 was an order of magnitude less active. Whereas a small alkyl substituent such as a methyl group resulted in a very potent FPT inhibitor (SCH 56580), introduction of bulky substituents such as tert-butyl, compound 33, or a phenyl group, compound 29, resulted in inactive FPT inhibitors. Polar groups at the 3-position such as amino 5, alkylamino 6, and hydroxyl 12 were less active. Whereas compound SCH 44342 did not show appreciable in vivo antitumor activity, the 3-bromo-substituted pyridyl N-oxide amide analogue 38 was a potent FPT inhibitor that reduced tumor growth by 81% when administered q.i.d. at 50 mpk and 52% at 10 mpk. These compounds are nonpeptidic and do not contain sulfhydryl groups. They selectively inhibit FPT and not geranylgeranyl-protein transferase-1 (GGPT-1). They also inhibit H-Ras processing in COS monkey kidney cells and soft agar growth of Ras-transformed cells.

High-performance liquid chromatographic determination and stability of 5-(3-methyltriazen-1-yl)-imidazo-4-carboximide, the biologically active product of the antitumor agent temozolomide, in human plasma

5-(3-Methyltriazen-1-yl)-imidazo-4-carboximide (MTIC) is a highly unstable compound which is believed to be the biologically active degradation product of the antitumor agent temozolomide. An HPLC method has been developed and validated for the analysis of MTIC in human plasma. Because of the instability of MTIC, sample processing was kept to minimal. The method involved precipitation of plasma protein with methanol followed by analysis of the supernatant using reversed-phase column and UV detection at 316 nm. The linearity (r>0.99), precision (C.V.<9%) and accuracy (bias<5%) were satisfactory. The lower limit of quantitation (LOQ) was 10 ng/ml. The recovery of MTIC and internal standard was > or = 86.7%. MTIC was stable in plasma though three freeze-thaw cycles, and was stable at 4 degrees C for 1 h and at -80 degrees C for at least 70 days. MTIC may be unstable at 10 degrees C in processed samples; therefore, samples were placed in the autosampler (10 degrees C) immediately prior to injection. By using this analytical method, MTIC was quantified in plasma of cancer patients (n=12) within 0.25-12 h after oral administration of temozolomide at 150 mg/m2. The mean maximum plasma concentration (Cmax) was 211 ng/ml which was observed at a mean Tmax of 1.88 h post dose. MTIC disappeared rapidly from plasma with an apparent in vivo half-life (t1/2) of 1.9 h similar to that of temozolomide. Following in vitro incubation of MTIC in human plasma at 25 degrees C, MTIC disappearance was bioexponential with estimated t1/2 values of 25 and 60 min for the first and second phases, respectively. Therefore, the elimination t1/2 of MTIC in human in vivo (1.9 h) was controlled by the rate of its formation from temozolomide.

Cerebral and umbilical vascular resistance response to vibroacoustic stimulation in growth-restricted fetuses

OBJECTIVE

To test the hypothesis that after vibroacoustic stimulation the ratio between cerebral vascular and umbilical vascular resistance in the growth-restricted fetus is different from that in the normal fetus.

METHODS

The pulsatility index (PI) of the middle cerebral artery and that of the umbilical artery (UA) were measured by pulsed Doppler velocimetry in 30 normal and 14 growth-restricted fetuses before and after vibroacoustic stimulation. The ratios of cerebral PI to UA PI and the changes in PI after vibroacoustic stimulation were calculated. Comparisons were made using the Wilcoxon rank-sum test or signed-rank test. The statistical power of the study was 80%.

RESULTS

Mean (+/- standard deviation) cerebral PI values before vibroacoustic stimulation (1.50 +/- 0.29) in normals and 1.29 +/- 0.26 in the fetal growth restriction [FGR] group) and UA PI values (1.00 +/- 0.18 in normals and 1.15 +/- 0.24 in the FGR group) were significantly different between groups (P < .04) and significantly decreased after vibroacoustic stimulation (P < .05). Although the cerebral to UA PI ratios (1.50 +/- 0.38 in normals and 1.13 +/- 0.33 in the FGR group) were significantly different between groups (P < .008), the values remained the same after vibroacoustic stimulation (P = .39 and .80, respectively). In all fetuses the fetal heart rate accelerated after vibroacoustic stimulation.

CONCLUSION

Cerebral vascular resistance was lower and umbilical vascular resistance higher in the growth-restricted fetuses than in normals. The vascular resistance response after vibroacoustic stimulation in the growth-restricted fetus was not significantly different from the response of the normal fetus, suggesting preservation of regulation of resistance.

Distinct clinicopathologic characteristics of diffuse- and intestinal-type gastric cancer in Taiwan

The clinicopathologic features of 221 patients with intestinal-type (IT) gastric cancer were compared retrospectively with those of 290 diffuse type (DT). Intestinal type was characterized by an older mean age (65.0 +/- 10.8 years vs. 56.2 +/- 13 years), a higher male-female ratio (2.56 vs. 1.06), predominance of blood group O (46.2% vs. 31.1%), and frequent habitual smoking (50.7% vs. 31.4%) and drinking (28.5% vs. 17.6%) than did DT. In contrast, DT had a higher frequency of positive history of parent or sibling with gastric cancer (9.3% vs. 4.1%) and blood group A (40.3% vs. 27.6%) than did IT. The distinguishing histologic features of DT included more Borrmann type IV (13.1% vs. 1.3%) but less Borrmann type I (1% vs. 7.2%), more frequent involvement of middle third (26.9% vs. 15.9%) and whole stomach (4.1% vs. 0%), and more peritoneal seeding (15.5% vs. 9%), lymph node metastasis (67.2% vs. 51%), and nerve permeation (34.1% vs. 24.4%), but less Helicobacter pylori infection (55.9% vs. 69.2%) when compared with those of IT. There was no difference in depth of tumor invasion, venous permeation, duodenal involvement, and postoperative survival between IT and DT. These distinct clinicopathologic features between IT and DT in Taiwan suggest the presence of a different pathogenic process for these two histologic subtypes of gastric cancer.

Low-flow anesthesia in adult orthotopic liver transplantation: a preliminary clinical experience

BACKGROUND

Anesthesia in orthotopic liver transplantation (OLT) may carry with complex hemodynamic, body temperature, and metabolic alterations. Although OLT cases increased in recent years in Taiwan, experiences remained limited. Notable advantage of low flow anesthesia may include reduced consumption of anesthetic gases and vapors, reduced environmental pollution and cost-saving. This study investigated patient profiles and the feasibility of low-flow rebreathing technique for adult orthotopic liver transplantation.

METHODS

Since June 1996, there were six OLT patients who received low flow anesthesia with isoflurane. All patients received hepatic veno-venal anastmosis (so-called piggy back procedure). Two patients were excluded from this study because of different surgical procedure (total occlusion of inferior vena cava and inferior vena cava veno-venal anastmosis). During maintenance of anesthesia, isoflurane was carried by a mixture of oxygen and air at a total fresh gas flow of 0.6 L/min. Alongside with the standard anesthesia machine and physiologic monitors, a newly designed Swan-Ganz catheter was introduced to measure and record cardiac output, systemic vascular resistance, pulmonary artery pressure, central venous pressure, and core temperature in a real-time manner. Blood samples were collected at 6 predetermined time-points in each patient for analysis of arterial blood gases, electrolytes, lactate and glucose concentrations.

RESULTS

The anesthetic time was 916 +/- 26 min (900 to 930 min). All patients regained their consciousness within 30 min after completion of surgery. The hemodynamics were relatively stable except after reperfusion of the liver. There was a significant decrease in mean arterial blood pressure, which occurred with accompaniment of a reduction of systemic vascular resistance and increased cardiac output. Arterial blood gas, electrolyte, and glucose were, however, maintained within acceptable limits. Blood lactate was progressively increased and reached its peak after reperfusion of the liver until the end of surgery. The core temperature was well maintained above 34 degrees C. No patient developed hypoxia or hypercapnia.

CONCLUSIONS

Low-flow rebreathing anesthetic technique maintained acceptable patient profiles and good body temperature preservation in orthotopic liver transplantation. These characteristics make it a promising method in maintenance of anesthesia for OLT.

Analysis of isepamicin in human plasma by radioimmunoassay, microbiologic assay, and high-performance liquid chromatography

Plasma concentrations of isepamicin, a new aminoglycoside antibiotic, were determined by radioimmunoassay (RIA), microbiological assay (MA), and high-performance liquid chromatography (HPLC) in healthy volunteers after administration of 7.5 mg/kg intramuscular dosages once daily for 10 days. Plasma samples were collected on days 1, 7, and 10. The limit of quantitation (LOQ) was 0.1 microg/ml for HPLC and RIA and 0.5 microg/ml for MA. The HPLC and RIA yielded superimposable plasma concentration-time curves, whereas the plasma concentrations obtained with MA appeared to be 20% to 30% lower. Regression analysis indicated good correlations among the three assays, with coefficients of correlation measuring 0.935 to 0.960 for RIA compared with HPLC, 0.925 to 0.945 for MA compared with HPLC, and 0.920 to 0.945 for RIA compared with MA.

Patient barriers to cancer pain management: from the viewpoint of the cancer patients receiving analgesics in a teaching hospital of Taiwan

BACKGROUND

The purpose of this study was to investigate the barriers to receiving analgesics for cancer pain in Taiwanese patients.

METHODS

The sample consisted of 128 hospitalized patients. All of the subjects were receiving analgesics. Three questionnaires entitled "Barriers Questionnaire-Taiwan Form (BQT)", "Brief Pain Inventory Short Form", and "Pain Management Index (PMI)" were used in this study. Data were analyzed using Student's t-test and Pearson correlation.

RESULTS

The results showed that most of BQT subscales including disease progression, time interval, tolerance, injection, addiction, fatalism and side effects were approaching toward the moderate or high end of the scale. 42.1% (n = 54) of the patients had negative PMI scores indicating that they were using less than adequate analgesics for pain. There was a significant difference between those who had adequate medication and those who did not, in terms of disease progression score and the total BQT score.

CONCLUSIONS

Overall the result revealed that pain management in these cancer patients was inadequate. Misconceptions on the part of patients still exist. Educational intervention could be an effective means for overcoming such barriers in Taiwanese patients who received analgesics for cancer pain.

Propofol anesthesia in a patient with Isaacs syndrome--report of a case and literature review

Isaacs syndrome is an unusual lower motor neuron disease characterized by myokymia (muscle twitching), muscular stiffness, and decreased tendon reflexes. We reported a patient who was affected with this rare disease, with manifestation of involuntary muscular contractions and required general anesthesia for bilateral tonsillectomies. Understanding the presentation and characterization of this unusual disease may be helpful in making choice of anesthetics or anesthetic techniques. Its possible mechanisms of action and its specific considerations in anesthesia in the literature are reviewed and discussed.

Loss of imprinting and overexpression of IGF2 gene in gastric adenocarcinoma

Both insulin-like growth factor II (IGF2) and H19 gene are located on chromosome 11p15.5 in close vicinity to each other, and are imprinted on different parental alleles. Although the exact mechanism remains unclear, loss of imprinting (LOI) leading to the biallelic expression of IGF2 and H19 genes has recently been reported in a variety of tumors. To study the role of IGF2 and H19 genes in gastric carcinogenesis, the LOI and loss of heterozygosity (LOH) status of these two genes were determined in 70 patients with gastric cancer. Among them, 30 patients were heterozygous for IGF2, 28 patients were heterozygous for H19, and 42 patients were heterozygous for either IGF2 or H19 gene. Among the 30 patients who were heterozygous for IGF2, one exhibited LOH (1/30, 3.3%) and 10 exhibited LOI (10/29, 34.5%). None of the 28 patients heterozygous for H19 gene had either LOH or LOI. LOI of IGF2 was more frequently found in the diffuse type (8/15, 53.3%) than the intestinal type (2/14, 14.3%, P < 0.05) gastric cancer. Five out of the six tumors with LOI of IGF2 exhibited overexpression of mRNA, but no obvious alterations of expression of H19 were noted by Northern hybridization. These data suggest that LOI leading to overexpression of IGF2 plays an important role in carcinogenesis of diffuse type gastric cancer.

Single-dose pharmacokinetics of isepamicin in young and geriatric volunteers

Isepamicin is a new aminoglycoside antibiotic with activity against both gram-negative and gram-positive bacteria. The pharmacokinetics of isepamicin were evaluated after a 0.5-hour intravenous infusion of alpha 15-mg/kg dose to groups of young adults and geriatric volunteers. Isepamicin was safe and well tolerated. No adverse events related to the infusion were reported. As age increased, there were increases in the elimination phase half-life (t1/2 beta) and the area under the plasma concentration-time curve extrapolated to infinity (AUC0-infinity), and decreases in systemic (Cl) and renal clearance (Clr). The changes seen in Cl with age were a result of changes in renal function estimated by creatinine clearance (Clcr). There were no apparent correlations between age and maximum plasma concentration (Cmax), half-life of the tau-phase (t1/2 tau), volume of distribution at steady-state (Vdss), or the amount of isepamicin excreted in urine within 24 hours after dose administration (Ae24 hrs). When comparing the elderly (61-80 years old) with the younger (21-60 years) volunteers, the (AUC0-infinity), and t1/2 beta values were higher in the elderly and the Cl and Clr values were lower, but Cmax, t1/2 tau and Vdss were similar in the two age groups. The contribution of the tau-phase to the overall AUC was minimal and similar for the two age groups. Also, there were no gender effects on the pharmacokinetics of isepamicin in both the young and elderly volunteers. These results demonstrate that changes in the pharmacokinetics of isepamicin in the elderly are attributable to changes in renal function, whereas age, per se, is not a significant factor.

Schizotypy in community samples: the three-factor structure and correlation with sustained attention

The authors examined cross-cultural applicability of the Schizotypal Personality Questionnaire (SPQ), the Perceptual Aberration Scale (PAS), and the Continuous Performance Test in community samples of Taiwanese adults and adolescents. The authors tested hypotheses that a 3-factor structure of the SPQ (Cognitive-Perceptual, Interpersonal, and Disorganization: A. Raine et al., 1994) exists for both samples and that the Interpersonal factor is associated with poorer attention. The authors replicated the 3-factor model for both samples, and they externally validated the model in adults: The Interpersonal factor and possibly the Disorganization factor were associated with poorer attention, whereas the Cognitive-Perceptual factor was not. The PAS differed from the Cognitive-Perceptual factor in its consistent association with poorer attention in both samples. These have important implications for the scales in the early detection of the schizotypy in various cultures.

The visible vessel on the bleeding gastric ulcer: an endoscopic-pathological study

BACKGROUND AND STUDY AIMS

The visible vessel is an important endoscopic sign for predicting rebleeding in ulcers. Freeman has described a visible vessel with a high rate of rebleeding as a "pearl" color (whitish) compared with a darkly colored "sentinel" clot with a low rebleeding rate. Clarifying the color of visible vessels helps to distinguish high-risk bleeding ulcers. We conducted a retrospective study that compared pathological findings with endoscopic pictures to determine the significance of the visible vessel's color.

PATIENTS AND METHODS

From January 1986 to December 1992, 110 patients who underwent endoscopy and received subtotal gastrectomies for ulcer bleeding were included in this study. Of these, 24 received endoscopic therapy before the operation. There were 94 males and 16 females, ranging in age from 30 to 90 years, with a mean age of 62.5 years. According to Freeman's report, a subgroup of visible vessels (IIav +) was defined as having either a "pearl-colored" collar around a red or black protruding mount or a "pearl-colored" mount on the ulcer base. The endoscopic findings were compared with the findings of the pathological specimens.

RESULTS

The endoscopic findings on the stigmata of recent hemorrhage in the 110 patients revealed that 31 were of type IIa (including 18 type IIav+ and 13 type IIav-), 56 of type IIb, 18 of type IIc, and 5 of type III. Fifty-four patients (49,1%) were found from their pathological specimen to have an eroded vessel on their ulcer base. Type IIa patients had a higher percentage of eroded vessels. The percentages of eroded vessels in types IIa, IIb, IIc, and III were 67.7%, 46.4%, 33.3%, and 20 %, respectively (P < 0.05, Fisher's exact test). Of the 54 patients with an eroded vessel in their pathological specimen, 13 (24 %) were found to have some vessel wall above the ulcer base (six in type IIa, four in type IIb, two in type IIc, and one in type III). Among the six with vessel wall above the ulcer base in type IIa, five patients (83 %) were identified as type IIav+ under endoscopy. There was a greater frequency of having a vessel wall above the ulcer base in type IIav+ than in type IIav- (38.5% vs. 12.5%) among the 31 endoscopic type IIa patients.

CONCLUSION

From this study, we determined that the wall of an eroded vessel on a gastric ulcer may protrude either above or below the ulcer base. A vessel wall on the ulcer base will appear pearl-colored under endoscopic view.

Cephalosporin 3'-phloroglucide esters and 7-(phloroglucidamido) cephalosporins as novel antibacterial agents

Two series of new phloroglucide derivatives were synthesized that possessed antibacterial activities. The first series includes cephalosporin 3'-phloroglucide esters 19 and 20, which were obtained by condensation of cephalosporin 16 with bioactive phloroglucides 14 and 15, respectively. They exhibited a dual mode of antibacterial action. In comparison with cephalosporins 26 and 27, bearing an acetoxy unit at the C-3' position, the bifunctional cephalosporins 19 and 20 showed a broadened spectrum of activity. Results from the consistent valence force field (CVFF) calculations indicate that the most stable conformational isomer of phenolic acid 14, holding a cis-syn-syn geometry, possessed a cavity. It provides an ideal environment to accommodate metal ions of holoenzymes. Phenolic keto acid 15, however, possessed a trans-anti-syn conformation, which allowed chelation between metal ions and the phenolic hydroxyl groups as well as the carbonyl functionalities. Our biological results show that the cavity formed in phloroglucides plays an important role. The second series includes 7-(phloroglucidamido)cephalosporins 24 and 25, which were synthesized by condensation of cephalosporin 21 with 14 and 15, respectively. Results from the CVFF calculations indicate that cephalosporin 24 also possessed a cavity. Unlike cephalosporin 3'-phloroglucide esters 19 and 20, cephalosporins 24 and 25 were found resistant to beta-lactamases from Staphylococcus aureus 95 and Pseudomonas aeruginosa 18S-H. These new compounds, however, showed notable activities against S. aureus FDA 209P, S. aureus 95, Candida albicans, P. aeruginosa 1101-75, and P. aeruginosa 18S-H.

Culture medium induced morphological changes of melanoma cells associated with change in sensitivity to lysis by lymphokine-activated killer cells

Three sublines (Clones 1, 2 and 7) of the human melanoma CaCL 73-36 cell line with different cellular morphology, growth patterns, melanin content and surface antigenic profile were maintained in RPMI-1640 medium plus 10% fetal bovine serum (abbreviated as RPMI). Each subline was divided into two groups: one grown in RPMI and the other in Dulbecco's modified Eagle's medium plus 10% fetal bovine serum (abbreviated as DMEM) for 96 h. Phenotypically, Clone 2 expressed Class I and II MHC and ICAM-1 on the surface and in the cytoplasm, while Clones 1 and 7 failed to express these antigens in both the cytoplasm and on the cell surface. Melanotic Clones 1 and 7 cells became even more pigmented, had slower growth rates, and exhibited lower saturation densities when incubated in DMEM than when they were incubated in RPMI. On the other hand, Clone 2 cells maintained in RPMI were grossly amelanotic, contained defective-like melanosomes detected ultrastructurally, and had distinct clusters of microvilli polarly located in most of the cells. Such specialized ultrastructures were not affected by medium conditions. Analysis of sensitivity of the clonal sublines to cytolysis by allogeneic effector cells revealed that in spite of low levels of natural killer (NK) cytotoxicity noted, DMEM produced a 2- to 14-fold increase in sensitivity to NK cells, irrespective of which medium was used. Different levels of lymphokine-activated killer (LAK) cytolytic activity were clearly observed in sublines maintained in RPMI, with Clone 2 being the most sensitive and both Clones 1 and 7 being less sensitive. Cells grown in DMEM exhibited significantly higher levels of sensitivity to LAK cytolysis than cells grown in RPMI as revealed by their differences in lytic units (p < 0.05). This was likely due to the high levels of surface ICAM-1 expression in cells incubated in DMEM vs little expression of this adhesion molecule by cells grown in RPMI. Taken together, these results demonstrate the presence of heterogeneous subpopulations within the CaCL 73-36 melanoma cell line regarding their pigmentary status, antigenic profile, growth pattern and responsiveness to NK/LAK cytolysis. The results also call attention to the importance of utilizing a same medium in short- and long-term cultures of melanomas for biological studies and response evaluations of therapeutic agents such as LAK cells, when multiple cell targets from different patients or multi-metastatic cell lines from individual patients are to be compared. Finally, these melanoma sublines may be valuable for further elucidation of the relationship between MHC expression, and increased sensitivity to LAK cytolysis, and the role of the components of DMEM in the mechanism for the observed induction of cell differentiation and enhanced LAK cytolysis.

Concentrations of serum interleukin-8 after successful cardiopulmonary resuscitation in patients with cardiopulmonary arrest

To assess differences in serum interleukin-8 concentrations in resuscitated and nonresuscitated patients after cardiopulmonary resuscitation (CPR), and to compare changes of interleukin-8 levels with hemodynamic variables after restoration of spontaneous circulation, 39 patients with out-of-hospital cardiopulmonary arrest who had undergone CPR were studied. Venous blood samples were taken after CPR and 1 and 2 hours after restoration of spontaneous circulation to measure serum interleukin-8 levels by the enzyme-linked immunosorbent assay method. The median serum interleukin-8 levels after CPR were significantly higher in resuscitated than in nonresuscitated patients (64.9 pg/ml; range 30.2 to 1497 vs 0 pg/ml; range 0 to 31.6 pg/ml; p < 0.001). One and 2 hours after restoration of spontaneous circulation, the median serum interleukin-8 levels were 96.2 pg/ml and 155.4 pg/ml, respectively. Mean values of systolic blood pressure immediately after and 1 and 2 hours after restoration of spontaneous circulation were 117 +/- 9 mm Hg, 130 +/- 11 mm Hg, and 136 +/- 13 mm Hg, respectively. No significant correlations were found between hemodynamic values and serum interleukin-8 levels. In conclusion, successful initial resuscitation was associated with increased serum interleukin-8 concentrations. The interleukin-8 levels remained at high values 2 hours after restoration of spontaneous circulation.

Human centromeric DNAs

Human centromeres have been extensively studied over the past two decades. Consequently, more is known of centromere structure and organization in humans than in any other higher eukaryote species. Recent advances in the construction of a human (or mammalian) artificial chromosome have fostered increased interest in determining the structure and function of fully functional human centromeres. Here, we present an overview of currently identified human centromeric repetitive DNA families: their discoveries, molecular characterization, and organization with respect to other centromeric repetitive DNA families. A brief examination of some functional based studies is also included.