Observation of a spin-flip M1 transition in 7(lambda)Li

Using a large-acceptance germanium detector array (Hyperball), we have observed a spin-flip M1 gamma transition between the ground-state spin doublet of (7)(Lambda)Li (3/2(+)-->1/2(+)). The observed energy of 691.7+/-0.6(stat)+/-1.0(syst) keV provides crucial information on the strength of the spin-spin interaction between a Lambda and a nucleon. This is the first observation of well-identified hypernuclear gamma transitions using germanium detectors.

Upper airway resistance syndrome and its treatment

Although upper airway resistance syndrome (UARS) is being recognized by a growing number of specialists, its prevalence remains unknown. UARS is associated with nocturnal and daytime complaints and oro-naso-maxillo-mandibular signs. Spectrum analysis of the nocturnal sleep EEG from the central leads indicates significant differences in absolute power in the 12-14 Hz and the 7-9 Hz bands of UARS patients compared to controls. The 0.5-2.0 Hz band also appears to be involved when analyses performed on matched controls are compared to results obtained in subjects treated with nasal CPAP. Several treatment avenues--nasal CPAP, dental devices, surgical procedures, and radiofrequency thermal ablation--have been used for the treatment of UARS. The number of subjects treated have been too low and the protocols too limited to arrive at appropriate outcome recommendations, but many of the approaches have shown positive results, suggesting the possibility of several treatment avenues.

Asymmetry in the nonmesonic weak decay of polarized (5)(Lambda)He hypernuclei

We have measured the asymmetric emission of protons from the nonmesonic decay of polarized (5)(Lambda)He produced by the (pi(+), K+) reaction. (5)(Lambda)He is an s-shell hypernucleus and its polarization is due to the Lambda. One expects to obtain direct information on the elementary weak Lambda-->p-->np process. The asymmetry parameter has been determined to be 0.24+/-0.22. The implication of the result is discussed.

Clinical implication of altered expression of Mad1 protein in human breast carcinoma

BACKGROUND

Mad1 protein is known to repress Myc target genes and antagonize Myc function. The authors undertook this study to investigate the clinical implication of Mad1 expression in human breast carcinoma.

METHODS

The authors performed immunohistochemical assays for Mad1 and Myc proteins in human breast carcinoma, along with tissues from normal breast and benign diseases. The data from protein assays were analyzed in terms of the clinical and biologic characteristics of the patients.

RESULTS

Of 66 patients with invasive ductal carcinoma, Mad1 expression was detected in 22 (33. 3%). Intensity and area of Mad1 expression significantly decreased in DCIS and invasive cancers, whereas high levels of Mad1 expression were persistent in benign breast lesions. Mad1 expression was significantly reduced in poorly differentiated tumors (P < 0.001). Expression of Mad1 was not associated with tumor size, lymph node status, or stage of disease. The authors did not observe any correlation between S-phase and expression status of Myc or Mad1. Mad1 expression was closely linked to differentiation of the cancer cells and inversely correlated with Myc expression (P = 0.042). In survival analysis, Mad1 was a significant factor in predicting recurrence of the disease, but not overall survival after CMF chemotherapy.

CONCLUSIONS

In human breast carcinoma cells, expression of Mad1 seems to be down-regulated, whereas expression of Myc is amplified. Altered expression of Mad1 may play a role in the malignant transformation of human mammary epithelial cells and represent an aggressive phenotype in human breast carcinoma.

Atomic-scale structure and catalytic reactivity of the RuO(2)(110) surface

The structure of RuO(2)(110) and the mechanism for catalytic carbon monoxide oxidation on this surface were studied by low-energy electron diffraction, scanning tunneling microscopy, and density-functional calculations. The RuO(2)(110) surface exposes bridging oxygen atoms and ruthenium atoms not capped by oxygen. The latter act as coordinatively unsaturated sites-a hypothesis introduced long ago to account for the catalytic activity of oxide surfaces-onto which carbon monoxide can chemisorb and from where it can react with neighboring lattice-oxygen to carbon dioxide. Under steady-state conditions, the consumed lattice-oxygen is continuously restored by oxygen uptake from the gas phase. The results provide atomic-scale verification of a general mechanism originally proposed by Mars and van Krevelen in 1954 and are likely to be of general relevance for the mechanism of catalytic reactions at oxide surfaces.

Actin-binding cellular proteins inside human immunodeficiency virus type 1

Host proteins are incorporated both on and inside human immunodeficiency virus type 1 (HIV-1) virions. To identify cellular proteins inside HIV-1, virion preparations were treated by a protease-digestion technique that removes external host proteins, allowing for the study of the proteins inside the virus. Treated HIV-1 preparations were analyzed by immunoblot, high-pressure liquid chromatography, and protein sequence analyses. These analyses identified several cellular proteins inside HIV-1: elongation factor 1alpha, glyceraldehyde-3-phosphate dehydrogenase, HS-1, phosphatidylethanolamine-binding protein, Pin1, Lck, Nm23-H1, and the C-terminal tail of CD43. Several of these proteins were found as fragments of their full-sized proteins that appear to be generated by our protease treatment of the virions, the HIV-1 protease, or a cellular protease. Recent advances in cell biology and biochemistry have identified some of these proteins as actin-binding proteins. These results support the hypothesis that actin filaments are incorporated into the virion and may provide additional clues for the understanding of the interaction between viral and cellular proteins during assembly and budding.

Current status of the Maze procedure for the treatment of atrial fibrillation

Since the first patient underwent the Maze procedure on September 25, 1987, 346 patients have undergone this operation for the treatment of atrial fibrillation. The procedure was designed as an open-heart operation performed through a median sternotomy. It underwent 2 major modifications relatively early in the series, evolving into the so-called Maze-III procedure, which has been used exclusively since April 16, 1992. Since that time, the Maze-III procedure has been adapted to allow it to be done by minimally invasive techniques. In addition, we recently performed the entire procedure in 2 patients without the use of cardiopulmonary bypass. The operative mortality rate has remained at 2% to 3%. This includes patients undergoing concomitant high-risk cardiac surgical procedures and all re-do cases. The overall success rate in curing atrial fibrillation has been 99%. The procedure itself has been shown to cause no permanent damage to the sinus node. The left atrium has been documented to function long-term postoperatively in 93% of patients and the right atrium functions in 99% of patients. The Maze-III procedure remains the surgical procedure of choice for the treatment of medically refractory atrial fibrillation.

Observations on the perioperative management of patients undergoing the Maze procedure

In addition to the usual measures that constitute optimal perioperative care after cardiac surgery, the Maze procedure demands several other measures because of certain complications that are unique to this particular operation. These complications include preoperative conditions such as amiodarone therapy, thromboembolism, diastolic dysfunction of the left ventricle, and associated valvular heart disease, as well as intraoperative differences that include multiple atriotomies and excision of both atrial appendages. The most common postoperative complications are atrial arrhythmias, excessive fluid retention, and pulmonary complications. In this article, we outline our own approach to the perioperative care of patients undergoing the Maze procedure.

The Maze-III procedure combined with valve surgery

Previous studies have suggested that the Maze procedure is not as effective in controlling atrial fibrillation when the arrhythmia is associated with significant valvular heart disease. In this study, we evaluate our own results in 83 patients who underwent 96 valve procedures in combination with the Maze-III procedure. Our results indicate that the Maze-III procedure is just as safe and effective in controlling atrial fibrillation associated with valvular heart disease as it is in controlling atrial fibrillation not associated with valvular heart disease.

Assay of 2-naphthol in human urine by high-performance liquid chromatography

This paper describes a novel liquid chromatographic method for the quantitation of 2-naphthol in human urine. Urine samples were extracted after enzymatic hydrolysis of glucuronides and sulfates; 2-naphthol was then separated using reversed-phase high-performance liquid chromatography. The corresponding detection limits were 0.04 ng/ml for the standard sample in acetonitrile and 0.13 ng/ml for urine samples. The level of urinary 2-naphthol in 100 Korean shipyard workers was analyzed using this new method. The level ranged from 0.21 ng/ml (0.26 micromol/mol creatinine) to 34.19 ng/ml (59.11 micromol/mol creatinine), and the mean+/-standard deviation was 5.08 ng/ml (6.60 micromol/mol creatinine)+/-5.75 ng/ml (9.22 micromol/mol creatinine). The mean+/-standard deviation of urinary 2-naphthol level of smokers, 7.03 ng/ml (8.49 micromol/mol creatinine)+/-6.16 ng/ml (10.23 micromol/mol creatinine), was significantly higher than that of non-smokers, 2.49 ng/ml (4.10 micromol/mol creatinine)+/-3.92 ng/ml (7.03 micromol/mol creatinine).

Studies in thoracic aortic graft infections: the development of a porcine model and a comparison of collagen-impregnated dacron grafts and cryopreserved allografts

OBJECTIVE

A porcine model of thoracic aortic graft infection was created, and various anatomic sites and the timing of inoculation of the graft to induce infection were investigated. Ultimately, the ability of cryopreserved allograft to resist infection was compared with that of collagen-impregnated Dacron graft.

METHODS

Yorkshire pigs (n = 16) underwent placement of an expanded polytetrafluoroethylene patch graft in the ascending aorta and the left atrial appendage (phase I). Eight animals were immediately given a 50-mL bolus (1 x 10(8) cfu/mL) of Staphylococcus aureus whereas the other 8 received the infusion 24 hours later. Animals were put to death 8 weeks later and the grafts were sterilely explanted and analyzed via microbiologic culture and standard histologic procedures for evidence of infection. The results displayed that the aortic graft and a delay of induced bacteremia of 24 hours were more reliable methods of producing infection. During phase II, 13 pigs were randomized to receive either a collagen-impregnated Dacron graft (n = 6) or a cryopreserved allograft (n = 7) in the ascending aortic position only and infusion of S aureus 24 hours after the operation. The experiment then proceeded to completion.

RESULTS

Phase I results displayed that use of an aortic graft and induced bacteremia 24 hours after the operation was a more reliable and reproducible method of producing infection. In phase II, graft infection was present in 38.5% (5/13) of animals, with only 16.7% (1/6) in the collagen-impregnated Dacron graft group and 57.2% (4/7) in the cryopreserved allograft group becoming infected. There was no significant difference between the collagen-impregnated Dacron graft and cryopreserved allograft groups in the incidences of thoracic aortic graft infections (P =.27, Fisher exact test).

CONCLUSIONS

This novel porcine model of thoracic aortic graft infection is a reproducible method for the investigation of thoracic aortic graft infections. The phase I study investigated the timing of the induced bacteremia and the most susceptible position of a graft. Phase II demonstrated that collagen-impregnated Dacron grafts are equivalent, if not superior, to cryopreserved allografts in resisting central vascular graft infections in the ascending aorta.

Solitary fibrous tumor of the lacrimal sac

PURPOSE

Solitary fibrous tumor is a rare spindle cell tumor arising in the pleura. We report two cases of this tumor occurring in the lacrimal sac.

METHODS

A 23-year-old man and a 34-year-old woman presented with a medial canthal mass. They underwent surgical excision of their tumors.

RESULTS

Solitary fibrous tumors were diagnosed by light microscopy, immunohistochemical study, and electron microscopy. Immunohistochemical staining showed that tumor cells were reactive with vimentin and CD34 and demonstrated no smooth muscle or neural differentiation (nonreactive with desmin and S-100 protein).

CONCLUSIONS

The findings indicate that solitary fibrous tumor can occur in the lacrimal sac and may recur locally if it is removed incompletely. To our knowledge, these are the first reported cases of solitary fibrous tumors occurring in the lacrimal sac.

c-Myc expression is related with cell proliferation and associated with poor clinical outcome in human gastric cancer

We underwent protein assay for Myc expression in 76 human gastric cancer tissues using immunohistochemistry. Expression of Myc protein was analyzed according to proliferative indices measured by flow cytometry. Levels of Myc protein expression was evaluated by correlating with biologic and clinical parameters. In 36 (47.4%) of 76 primary gastric cancers, overexpression of Myc was observed. We could observe expression of Myc protein in a significant portion of early gastric cancer (42.9%). Expression of Myc protein was demonstrated to be more frequent in poorly differentiated cancer cells (p=0.043). However, expression of Myc protein had little influence over progress or extent of the disease. Expression of Myc protein was significantly correlated with increased proliferative activity (p=0.032) and patients with high levels of Myc expression had poor disease-free survival. In a certain proportion of human gastric cancer, Myc protein may function as a regulator of cancer cell growth and expression of Myc may represent an aggressive phenotype of gastric cancer.

Toll4 (TLR4) expression in cardiac myocytes in normal and failing myocardium

Expression of innate immune response proteins, including IL-1beta, TNF, and the cytokine-inducible isoform of nitric oxide synthase (iNOS), have been documented in the hearts of humans and experimental animals with heart failure regardless of etiology, although the proximal events leading to their expression are unknown. Noting that expression of a human homologue of Drosophila Toll, a proximal innate immunity transmembrane signaling protein in the fly, now termed human Toll-like receptor 4 (hTLR4), appeared to be relatively high in the heart, we examined TLR4 mRNA and protein abundance in isolated cellular constituents of cardiac muscle and in normal and abnormal murine, rat, and human myocardium. TLR4 expression levels in cardiac myocytes and in coronary microvascular endothelial cells could be enhanced by either LPS or IL-1beta, an effect inhibited by the oxygen radical scavenger PDTC. Transfection of a constitutively active TLR4 construct, CD4/hTLR4, resulted in activation of a nuclear factor-kappaB reporter construct, but not of an AP-1 or an iNOS reporter construct, in cardiac myocytes. In normal murine, rat, and human myocardium, TLR4 expression was diffuse, and presumably cytoplasmic, in cardiac myocytes. However, in remodeling murine myocardium remote from sites of ischemic injury and in heart tissue from patients with idiopathic dilated cardiomyopathy, focal areas of intense TLR4 staining were observed in juxtaposed regions of 2 or more adjacent myocytes; this staining was not observed in control myocardium. Increased expression and signaling by TLR4, and perhaps other Toll homologues, may contribute to the activation of innate immunity in injured myocardium.

Expression of p27Kip1 and cyclin D1 proteins is inversely correlated and is associated with poor clinical outcome in human gastric cancer

BACKGROUND AND OBJECTIVES

p27Kip1 is an inhibitor of cyclin-dependent kinases and is speculated to be a potential prognostic indicator in numerous human cancers. We investigated expression of p27Kip1 along with cyclin D1 in gastric cancer to estimate the clinical utility of p27Kip1.

METHODS

Immunohistochemical assay for p27Kip1 and cyclin D1 proteins was performed in 64 patients with primary gastric cancer. Correlation between p27Kip1 expression and clinical-biological parameters including patient survival was analyzed.

RESULTS

p27Kip1 expression was suppressed in 40 (62.5%) of 64 gastric cancer patients and cyclin D1 was overexpressed in 22 (34.4%) out of 64. Expression of p27Kip1 was significantly reduced in poorly differentiated cancers (82.1%, 23/28; P = 0.015) and was also reduced in the tumors with high S-phase fraction (86.7%, 26/30) compared with tumors showing low S-phase fraction (41.2%, 14/34; P = 0.0002). Expression of p27Kip1 and cyclin D1 was inversely correlated (P = 0.021). In univariate analysis, extent of the disease (P < 0.001), expression of cyclin D1 (P = 0.0001), and reduced expression of p27Kip1 (P = 0. 0006), were statistically significant to predict patient's outcome, but depth of invasion (P = 0.008) and pathologic stage (P = 0.009) emerged as significant prognostic indicators in multivariate analysis.

CONCLUSION

Expression of p27Kip1 is closely linked with cell proliferation and differentiation of human gastric cancer. p27Kip1 seems to have potential as a prognostic marker in the management of gastric cancer patients.

Expression of Mad1 protein inhibits proliferation of cancer cells and inversely correlated with Myc protein expression in primary gastric cancer

We performed immunohistochemical assay for Mad1 and Myc protein in 76 gastric cancer tissues. Cancers with reduced Mad1 expression had high proliferative index (S and G2/M-phase) and there was inverse correlation between Mad1 and Myc expression in the same cancer cells. There was no significant correlation between expression of Mad1 and cell differentiation or extent of the disease. There was a trend that reduced expression of Mad1 was associated with poor survival of the patients. Mad1 may influence biologic behavior of cancer cell by inhibiting transcriptional activity of Myc and reduced levels of Mad1 expression seem to be associated with carcinogenesis in human gastric cancer.

Reduced expression of p27Kip1 protein is associated with poor clinical outcome of breast cancer patients treated with systemic chemotherapy and is linked to cell proliferation and differentiation

The cyclin-dependent kinase inhibitor p27Kip1 is a negative regulator of cell proliferation. Its expression is known to be altered in a proteasome-dependent manner without changes in DNA level. Reduced expression of p27Kip1 is associated with aggressive behavior in a variety of human cancers. We investigated expression of p27Kip1 protein in human breast cancer using immunohistochemistry to assess its biologic implication along with cell-cycle analysis by flow cytometry. A total of 68 patients with invasive ductal cancer received adjuvant chemotherapy with cyclophosphamide, methotrexate, and 5-FU every 3 weeks for six cycles. In epithelial cells of normal and benign breast disease, expression of p27Kip1 was well preserved while its expression markedly decreased in breast cancer (45 of 68). Expression of p27Kip1 is significantly reduced in poorly differentiated cancers and in the advanced stage of the disease. Levels of p27Kip1 expression correlated with cell populations in G0/G1 phase of the cell cycle. In survival analysis, p27Kip1 was useful to predict disease free survival but not overall survival of the patients after adjuvant chemotherapy. In summary, p27Kip1 seems to have a role in the cell proliferation and differentiation process during carcinogenesis of breast cancer. The results of the present study suggest that p27Kip1 can be used in predicting response to systemic chemotherapy in a subset of patients with breast cancer.

123I-IPT brain SPECT study in essential tremor and Parkinson's disease

OBJECTIVE

To investigate nigral neuronal damage in patients with isolated postural tremor and those with postural and rest tremor without parkinsonism.

METHODS

Using [123I]-N-(3-iodopropen-2-yl)-2 -carbomethoxy-3beta-(4-chlorophenyl) tropane SPECT, we measured the basal ganglia-occipital cortex/occipital cortex ([BG-OCC]/OCC) uptake ratios in 21 control subjects and patients with isolated postural tremor (n = 9), postural and rest tremor (n = 6), and PD (n = 11).

RESULTS

In the patients with PD, the means (+/-SD) of the (BG-OCC)/OCC ratios of the ipsilateral (2.35+/-0.37) and the contralateral (1.97+/-0.33) sides to the more severely affected limbs were significantly lower than the mean of the bilateral (BG-OCC)/OCC ratios of the age-matched control subjects (3.83+/-0.66). The mean (+/-SD) of the bilateral (BG-OCC)/OCC ratios of the patients with isolated postural tremor (3.60+/-0.83) was comparable with that of the age-matched control subjects. However, the mean (+/-SD) of the bilateral (BG-OCC)/OCC ratios of the patients with postural and rest tremor (2.61+/-0.18) was lower than that of the control subjects (p < 0.05). The mean of the bilateral (BG-OCC)/OCC ratios of the patients with postural and rest tremor was comparable with that of the side ipsilateral to the severely affected limbs of the patients with PD. However, it was higher than that of the side contralateral to the limbs more severely affected by PD. Four of the six patients with postural and rest tremor had (BG-OCC)/OCC ratios lower than 2 standard deviations from the mean of the age-matched control subjects.

CONCLUSIONS

Later in their clinical courses, some patients with postural tremor may acquire rest tremor in association with mild substantia nigra neuronal loss.

Comparative studies of Nsc and Fmoc as N(alpha)-protecting groups for SPPS

2-(4-Nitrophenyl)sulfonylethoxycarbonyl (Nsc) is an alternative base-labile N(alpha)-protecting group to 9-fluorenylmethoxycarbonyl (Fmoc) for amino acids. The UV spectrum of the Nsc group exhibits moderate absorption at 380 nm which is excellent for real-time monitoring of the deprotection process. It also decreases the rearrangement of X-Asp, which can be a serious problem in SPPS.

Nonanticoagulant heparin prevents coronary endothelial dysfunction after brief ischemia-reperfusion injury in the dog

BACKGROUND

Coronary endothelial dysfunction after brief ischemia-reperfusion (IR) remains a clinical problem. We investigated the role of heparin and N-acetylheparin, a nonanticoagulant heparin derivative, in modulating coronary endothelial function after IR injury, with an emphasis on defining the role of the nitric oxide (NO)-cGMP pathway in the heparin-mediated effect.

METHODS AND RESULTS

Male mongrel dogs were surgically instrumented, and the effects of both bovine heparin and N-acetylheparin on coronary endothelial vasomotor function, expressed as percent change from baseline flow after acetylcholine challenge, were studied after 15 minutes of regional ischemia of the left anterior descending artery (LAD) followed by 120 minutes of reperfusion. In dogs treated with placebo (saline), coronary vasomotor function was significantly (P</=0.03) decreased after 15 and 30 minutes of reperfusion (65+/-12% and 73+/-12%) compared with preischemia (103+/-6%). In contrast, the vasodilatory response to the endothelium-independent vasodilator sodium nitroprusside was maintained during reperfusion. Preischemic administration of both bovine heparin and N-acetylheparin (6.0 mg/kg IV) preserved coronary endothelial function throughout reperfusion. In a parallel group of dogs, nitrate/nitrite (NOx) and cGMP levels in the LAD were measured after treatment and during 15-minute reperfusion. Preischemic administration of N-acetylheparin caused a significant increase in basal NOx and cGMP levels compared with saline controls. Pretreatment with N-acetylheparin also caused a significant increase in NOx and cGMP levels in the LAD after 15 minutes of reperfusion compared with IR alone.

CONCLUSIONS

These results suggest that heparin preserves coronary endothelial function after brief IR injury by a mechanism independent of its anticoagulant activity and that the effect of heparin may be mediated in part by activation of the NO-cGMP pathway.