IL-1 is an important mediator for microcirculatory changes in endotoxin-induced intestinal mucosal damage

Although small intestine is frequently injured in endotoxin shock, the exact pathological sequence has not been fully understood. The major objective of this study is to elucidate the role of interleukin (IL)-1 in endotoxin-induced microcirculatory disturbance of rat small intestine. Mucosal and submucosal microvessels of the rat ileum were observed by intravital microscope with a high speed video camera system and the attenuating effect of E5090, an inhibitor of IL-1 generation, on endotoxin-induced intestinal microcirculatory disturbances was investigated. Endotoxin infusion produced significant mucosal damage, but before these morphological changes became significant, microvascular stasis in villi, decreased red blood cell velocity, and increased leukocyte adherence to venular walls were observed in intestinal microcirculatory beds 30 min after endotoxin administration. Intestinal IL-1alpha levels were also significantly increased at that time. Endotoxin treatment enhanced chemiluminescence activity from neurophils and rapidly mobilized CD18 on leukocytes. E5090, which suppressed the IL-1 production in intestinal mucosa, attenuated the microcirculatory disturbances induced by endotoxin, and significantly reduced the subsequent mucosal damage. E5090 also attenuated the increased chemiluminescence activity and CD18 expression on leukocytes. In conclusion, the production of IL-1alpha is enhanced in the intestinal mucosa during endotoxin infusion. IL-1 may be an important mediator of microcirculatory changes, including decreased red blood cell velocity and increased leukocyte sticking and its activation, leading to the mucosal damage.

Breakpoint diversity illustrates distinct mechanisms for Robertsonian translocation formation

Robertsonian translocations are the most common chromosomal rearrangements in humans. The vast majority of the ten possible nonhomologous types of Robertsonian translocations ascertained are rob(13q14q) and rob(14q21q). Recombination between homologous sequences on nonhomologous chromosomes has been proposed as a mechanism leading to the preferential formation of rob(13q14q) and rob(14q21q). However, little evidence exists to indicate whether the remaining less common Robertsonian translocations form through a similar mechanism. To better elucidate the mechanisms involved in Robertsonian translocation formation, we have used fluorescence in situ hybridization to localize the breakpoints in 56 nonhomologous Robertsonian translocations. This study revealed highly variable locations of breakpoints in seven types of the less common Robertsonians, while nearly all rob(13q14q) and rob(14q21q) analyzed displayed breakpoints in the same locations. Therefore, this study provides direct evidence that rob(13q14q) and rob(14q21q) form through a specific mechanism, possibly involving homologous recombination, which is distinct from the mechanism(s) that contributes to the formation of the remaining types of Robertsonian translocations.

Roles of ET-1 in endotoxin-induced microcirculatory disturbance in rat small intestine

The major objective of this study was to investigate whether endothelin-1 (ET-1) plays a significant role in endotoxin-induced microcirculatory disturbances of the intestinal mucosa. Submucosal microvessels of the rat ileum were observed by intravital microscopy with a high-speed video camera system. Preceding the apparent intestinal mucosal damage, red blood cell (RBC) velocity was significantly decreased 30 min after endotoxin treatment in both arterioles and venules. The number of leukocytes sticking to submucosal venules was significantly increased at 30 min. BQ-123, an ETA-receptor antagonist, significantly attenuated the decrease in RBC velocity and also prevented an increase in leukocyte sticking as well as the subsequent mucosal damage induced by endotoxin. The ET-1 concentrations began to be elevated in plasma at 15 min and in the mucosa at 30 min and subsequently further increased in a time-dependent manner. A significant decrease in calcium-dependent nitric oxide synthase activity and significant increases in the concentration of platelet-activating factor (PAF) were demonstrated in the intestinal mucosa after endotoxin treatment. BQ-123 also significantly attenuated these changes. We concluded that the increased ET-1 production in intestinal mucosa induced by endotoxin stimulation could lead to leukocyte sticking and decreased RBC velocity in the intestinal microcirculatory beds via ETA receptors, which are closely related to increased production of PAF and decreased synthesis of constitutive nitric oxide.

Transaxillary minithoracotomy versus video-assisted thoracic surgery for spontaneous pneumothorax

BACKGROUND

Although management of spontaneous pneumothorax by video-assisted thoracic surgery (VATS) has generally shown superior clinical results to thoracotomy, management of spontaneous pneumothorax by transaxillary minithoracotomy (TAMT) has also shown good clinical results. The objective of this study was to compare the clinical results of VATS and TAMT in treating spontaneous pneumothorax.

METHODS

Sixty-six patients, aged 13 to 81 years, with recurrent, persistent or contralateral spontaneous pneumothorax were involved in this study. Thirty-six patients were treated by VATS and 30 by TAMT. The operating time, the amount of analgesics used on the first postoperative day, the duration of the indwelling chest tube, and the number of recurrences after operation were compared. The follow-up periods of both procedures were from 6 to 24 months.

RESULTS

Of the 66 patients, 64 were male and 2 were female. The duration of operation, from start of skin incision to insertion of chest tube, was 91.2 +/- 36.8 minutes in VATS and 86.3 +/- 40.9 minutes in TAMT (p = 0.6061). The amount of analgesics (keptoprofen) used was 1.9 +/- 2.3 ampules in VATS and 2.1 +/- 2.9 ampules in TAMT (p = 0.0883). The duration of indwelling chest tube was 5.0 +/- 4.0 days in VATS and 4.3 +/- 2.1 days in TAMT (p = 0.3707). The number of recurrences after operation was 4 in VATS and none in TAMT.

CONCLUSIONS

There were no advantages of VATS over TAMT for management of recurrent, persistent, or contralateral spontaneous pneumothorax in regard to the operating time, the amount of analgesics used on the first postoperative day, the duration of the indwelling chest tube, and the number of postoperative recurrences in patients with apical bullae.

Pharmacokinetics and efficacy of low-dose all-trans retinoic acid in the treatment of acute promyelocytic leukemia

A clinical trial was conducted in order to evaluate the therapeutic effect and side-effects of low-dose ATRA in the treatment of acute promyelocytic leukemia (APL). We compared the pharmacokinetic features in normal individuals with single oral ATRA at 15 mg/m2 and 45 mg/m2, respectively. The results showed that maximal plasma concentration (Cpmax) with oral 15 mg/m2 ATRA was high enough (10(-6) M) to induce APL cell differentiation. Based on these results, 27 cases of de novo APL patients were treated with continuous oral ATRA at the dose of 15-20 mg/m2/day and 24/26 evaluable cases (92%) achieved clinical CR after 13 to 67 days of ATRA treatment. No patient experienced RAS and DIC. The Cpmax with a single dose of ATRA on day 1 of treatment and immediately at CR obtained with continuous ATRA in three cases demonstrated similar values in one patient and an approximately two-fold decrease in two patients. More importantly, compared with a relatively well-matched historic group of 20 APL patients treated with high-dose ATRA, our results suggest that low-dose ATRA is as effective as high-dose in treating APL patients and may provide advantages through decreased hyperleukocytosis and other side-effects.

Enhanced levels of chemiluminescence and platelet activating factor in urease-positive gastric ulcers

Helicobacter pylori are believed to play an important role in the formation of gastric ulcer in a syndrome characterized by a high urease activity. On the other hand, the production of oxygen radicals and platelet activating factor (PAF) is enhanced in gastric ulcers. The present study is designed to investigate the relationship between the different aspects of gastric mucosal injury, urease activity, oxygen radical production, and PAF content in gastric specimens. Biopsy specimens taken from 35 gastric ulcer patients were studied. Urease activity was detected by a rapid urease test (CLO). Oxygen radical production was measured as a value of luminol-dependent chemiluminescence (ChL) and PAF content was determined by radioimmunoassay in the biopsy samples. The CLO-positive rate was significantly higher in the gastric ulcer group in comparison with that in controls. ChL values and PAF content were significantly increased in gastric ulcers, especially in CLO-positive specimens. The CLO-positive rate, ChL values, and PAF content were also found to be increased at a distant site beyond the ulcer lesions. During the course of macroscopic ulcer healing of CLO-positive cases, the CLO positive level and the ChL values were not significantly decreased, although PAF content was significantly lower. Enhanced oxygen radical and PAF production were observed not only in the ulcer region but also at a distant site from the ulcer in the urease-positive gastric mucosa. The persistent enhancement of ChL values during the healing stage of urease-positive gastric ulcers suggests its involvement in the recurrence of gastric ulcers.

Kinetic studies on the reduction of the tyrosyl radical of the R2 subunit of E. coli ribonucleotide reductase

Kinetic studies at 25 degrees C, I = 0.100 M (NaCl), on the reduction of the tyrosyl radical of the R2 protein of E. coli ribonucleotide reductase with hydroxyurea (HU), N-methylhydroxylamine, catechol, and seven hydroxamic acid derivatives are reported. There are no pH-dependences in the range 6.2-8.6 investigated except that introduced with N-methylhydroxylamine which itself protonates in this range. At pH 7.6 the rate constant (0.46 M-1 s-1) for the HU reaction is in agreement with earlier values. Slower reactions are observed with the bulkier acetohydroxamic (0.020 M-1 s-1) and benzohydroxamic acids (0.040 M-1 s-1). In the case of N-methylhydroxylamine the rate constant (0.41 M-1 s-1 at pH 7.6) decreases with pH, and it is concluded that the protonated form CH3NH2+OH(pKa = 6.2) has little or no reactivity with Tyr. For this reaction under air-free conditions a second-stage (0.027 M-1 s-1) corresponding to reduction of Fe(III)2 is observed. Mid-point redox potentials for the reductants and estimates of reduction potentials applying in the case of the protein are considered. The reactions with 1,2-dihydroxybenzene (catechol) and 3,4-dihydroxybenzohydroxamic acid (Didox) also have two stages, when the initial Tyr reduction, rate constants/M-1 s-1 for catechol (3.2) and Didox (0.010), is followed by removal of the Fe(III) to give catechol and catechol like Fe(III)-complexed products. The single stage reactions of the hydroxamic acid derivatives which incorporate charged amino-acid groups L-glutamic acid, L-histidine, L-glycine and L-lysine, are slow, and saturation kinetics are observed consistent with association (small K values) prior to redox. The mechanism of reduction of R2-Tyr by all of the reagents studied is discussed.

Molecular characterization of de novo secondary trisomy 13

Unbalanced Robertsonian translocations are a significant cause of mental retardation and fetal wastage. The majority of homologous rearrangements of chromosome 21 in Down syndrome have been shown to be isochromosomes. Aside from chromosome 21, very little is known about other acrocentric homologous rearrangements. In this study, four cases of de novo secondary trisomy 13 are presented. FISH using alpha-satellite sequences, rDNA, and a pTRI-6 satellite I sequence specific to the short arm of chromosome 13 showed all four rearrangements to be dicentric and apparently devoid of ribosomal genes. Three of four rearrangements retained the pTRI-6 satellite I sequence. Case 1 was the exception, showing a deletion of this sequence in the rearrangement, although both parental chromosomes 13 had strong positive hybridization signals. Eleven microsatellite markers from chromosome 13 were also used to characterize the rearrangements. Of the four possible outcomes, one maternal Robertsonian translocation, two paternal isochromosomes, and one maternal isochromosome were observed. A double recombination was observed in the maternally derived rob(13q13q). No recombination events were detected in any isochromosome. The parental origins and molecular chromosomal structure of these cases are compared with previous studies of de novo acrocentric rearrangements.

Molecular cytogenetic characterization of 17 rob(13q14q) Robertsonian translocations by FISH, narrowing the region containing the breakpoints

We have characterized 17 rob(13q14q) Robertsonian translocations, using six molecular probes that hybridize to the repetitive sequences of the centromeric and shortarm regions of the five acrocentric chromosomes by FISH. The rearrangements include six de novo rearrangements and the chromosomally normal parents, five maternally and three paternally inherited translocations, and three translocations of unknown origin. The D21Z1/D13Z1 and D14Z1/D22Z1 centromeric alpha-satellite DNA probes showed all rob(13q14q) chromosomes to be dicentric. The rDNA probes did not show hybridization on any of the 17 cases studied. The pTRS-47 satellite III DNA probe specific for chromosomes 14 and 22 was retained around the breakpoints in all cases. However, the pTRS-63 satellite III DNA probe specific for chromosome 14 did not show any signals on the translocation chromosomes examined. In 16 of 17 translocations studied, strong hybridization signals on the translocations were detected with the pTRI-6 satellite I DNA probe specific for chromosome 13. All parents of the six de novo rob(13q14q), including one whose pTRI-6 sequence was lost, showed strong positive hybridization signals on each pair of chromosomes 14 and 13, with pTRS-47, pTRS-63, and pTRI-6. Therefore, the translocation breakpoints in the majority of rob(13q14q) are between the pTRS-47 and pTRS-63 sequences in the p11 region of chromosome 14 and between the pTRI-6 and rDNA sequences within the p11 region of chromosome 13.

Solitary rectal ulcer syndrome

We report three cases of solitary rectal ulcer syndrome (SRUS). The diagnosis was established according to histopathologic criteria. But, the initial clinical diagnosis was carcinoma, non-specific ulcer and localized proctitis respectively. SRUS is considered as one of functional disorder in pelvic floor which might go underdiagnosed due to unfamiliar concept in Korea. So we should consider SRUS to be one of the differential diagnosis in cases of complaining anorectal symptoms.

'Pauci-immune' rapidly progressive glomerulonephritis associated with systemic vasculitis

'Pauci-immune' glomerulonephritis has been recognized as an important cause of rapidly progressive glomerulonephritis. The paucity of immune deposits can be separated from the other two major immunohistologic variants of crescentic glomerulonephritis, ie, antiglomerular basement membrane (GBM) antibody-mediated and immune complex-mediated glomerulonephritis. Here we describe the case of a 42-year-old woman with pauci-immune' glomerulonephritis and vasculitis presenting as rapidly progressive renal failure with characteristic pathologic and immunohistologic findings. And in this case, despite oliguria and rapid deterioration of renal function, the renal function recovered partially and continued to be stabilized with a favourable response to hemodialysis and combined system immunosuppressive therapy.

Kashin-Beck disease: a cross-sectional study in seven villages in the People's Republic of China

Kashin-Beck disease (KBD) is an endemic disease that occurs in certain parts of the People's Republic of China and in Russia. The etiology of the disease is unknown. Selenium deficiency, mycotoxins, and chelating agents such as humic acid and decaying plant material from walnut tree forests have been suggested as causal agents. The primary lesion of this disease is the selective coagulative necrosis of the hypertrophic chondrocytes at the base of the articular and growth plate cartilages. A cross-sectional study was performed in the People's Republic of China in 7 villages, to focus on information about life styles, food consumption, and environmental factors from the village population where the disease is endemic. A total of 425 children were examined, of which 71 children had KBD. Results of detailed food consumption data analyses showed that certain combinations of food substances high in protein had a protective effect. It was also found that the disease was twice as prevalent in onset in boys as in girls, in the 12-yr-old age group. The overall onset of illness in this group of children ranged from 4 to 13 yr. Either the joints of the fingers or one ankle was affected first. Many of these children also had discolored teeth. However, this finding was unrelated to KBD.