Management of acute pancreatitis: results of a 15-year experience in Taiwan

In the past two decades, there have been great changes regarding the policy for treating acute pancreatitis. The aim of this study was to examine the chronological changes in the management of acute pancreatitis in a tertiary referral center. A retrospective review was carried out of the management approaches for acute pancreatitis in the 15 years since 1984. The patients were divided into groups according to the admission date, representing two periods: period 1, from 1984 through 1992; and period 2, from 1993 through 1999. Decision-making for treating acute pancreatitis was based mainly on Beger's criteria. The background features and treatment outcome were compared between the two periods. The severity of pancreatitis was based on the Atlanta classification system. Octreotide was available from January 1993. No differences could be found between the two periods regarding the patients' background characteristics or severity of pancreatitis. Patients in period 2 had a longer interval between the onset of pancreatitis and surgery, and a lower incidence of pancreatectomy. Although the surgical morbidity, mortality, and reoperation rates were not significantly different between the two periods, more patients with severe acute pancreatitis in period 2 received nonsurgical treatment, and a lower mortality rate was also noted. With improvements in critical care, increasing experience, and better surgical techniques, even patients with severe acute pancreatitis can be treated by nonsurgical means. However, aggressive surgical intervention is necessary for patients who have signs of infected necrosis and whose disease is not controllable by conservative methods.

Humoral and cellular immune responses in turkey poults infected with turkey coronavirus

The objective of the present study was to elucidate the kinetics of humoral and cellular immune responses of turkey poults infected with turkey coronavirus (TCV). Turkey poults were orally inoculated with TCV at 10 d of age, and the immune responses were analyzed at 1, 3, 7, 14, 21, 28, 42, and 63 d postinfection (PI) in three different experiments. Total Ig to TCV was initially detected at 7 and 14 d PI in Experiments 1 and 3. In addition, Ig gradually increased from 7 to 21 d PI and remained at 80 immunofluroescent antibody assay (IFA) titers or more thereafter. Lymphocyte proliferation responses of spleen cells to concanavalin A were higher in TCV-infected turkeys than in noninfected control turkeys with significant differences (P < 0.05) being noted at 14 and 63 d PI in Experiment 2 and at 3 and 28 d PI in Experiment 3. Strong IFA staining response to TCV antigen was observed in intestines of turkeys at 1, 3, and 7 d PI, and the response declined from 14 to 28 d PI in Experiment 3. In Experiment 3, the IgG isotype antibody response to TCV was markedly increased after 21 d PI and remained high until 63 d PI. The IgM isotype antibody response to TCV was 1.40 and 0.91 at 7 and 14 d PI, respectively. The IgA isotype antibody response to TCV was very low as detected at 7 (0.13), 14 (0.20), and 21 (0.17) d PI. Turkeys infected with TCV had significantly higher (P < 0.05) antibody response to sheep erythrocytes than noninfected controls at 7 d PI. Virus-specific lymphocyte proliferation response of spleen cells was significantly stimulated (P < 0.05) at 63 d PI in Experiment 3. The proportion of the CD4+ subpopulation of T lymphocytes was significantly increased (P < 0.05) at 1, 7, and 21 d PI in Experiment 3. The results indicate that humoral and cellular immunities to TCV are elicited in turkeys following infection with TCV.

Needlescopic, laparoscopic, and open appendectomy: a comparative study

SUMMARY

The benefits of laparoscopic appendectomy appear to be controversial. Since 1994, several abdominal procedures have been completed by using the needlescopic technique, but there appear to be no prospective studies to demonstrate the perceived benefits of needlescopic appendectomy. The authors compared open, laparoscopic, and needlescopic appendectomy in a randomized fashion with regard to duration of surgery, length of hospitalization, analgesic dosage, and surgery-associated complications. From March to July 1998, 75 patients admitted at the emergency station of the authors' hospital with a final diagnosis of acute appendicitis without tumor formation were randomized to receive one of the three treatment categories: open (OA), laparoscopic (LA), and needlescopic (nLA) appendectomy. Laparoscopic and needlescopic appendectomy were performed by using a three-port technique, although the size of the trocar used varied. There were 26 patients in the OA group, 23 in the LA group, and 26 in the nLA group. The mean operation durations for the OA, LA, and nLA groups were 55.4 +/- 28.0 minutes, 69.1 +/- 48.8 minutes, and 62.3 +/- 26.3 minutes, respectively, and these were not significantly different from one another. The mean number of the analgesic doses (Pethidine 1 mg/kg) required was 1.3 +/- 1.2 mg/kg, 0.5 +/- 0.8 mg/kg, and 0.2 +/- 0.6 mg/kg, respectively. Significant differences were noted when comparing the OA with the LA or nLA groups (OA vs. LA, P = 0.02; OA vs. nLA, P = 0.0002; LA vs. nLA, P = 0.06). The mean oral intake durations were 32.2 +/- 16.9 hours, 21.0 +/- 14.6 hours, and 20.8 +/- 16.4 hours, respectively, after surgery for the OA, LA, and nLA groups, and the between-group differences were statistically significant for the OA versus LA group ( P = 0.004) and for the OA versus nLA group ( P = 0.003). The mean durations of hospitalization for the OA, LA, and nLA groups were 3.6 +/-1.8 days, 2.8 +/- 1.4 days, and 2.4 +/- 0.9 days, and difference was detected between the OA and the nLA groups ( P = 0.02). The OA group rendered a greater wound-complication rate and ileus than did the other two groups, but the differences were not detected between the three categories ( P = 0.065, 0.6935). The result of the current study confirmed that the nLA procedure is a feasible and safe one. The nLA procedure provided substantial advantages over the OA procedure in the contexts of diminished postoperative pain and shorter hospital stay without significant increases in postoperative complication rate or surgical time.

Treatment of femoral shaft aseptic nonunion associated with plating failure: emphasis on the situation of screw breakage

BACKGROUND

Femoral shaft aseptic nonunions associated with plating failure resulting from screw breakage are rare, and the treatment is complex and yet to be defined. The aim of this prospective study was to develop a better technique for the treatment of this complication.

METHODS

Eight consecutive adult patients who sustained femoral shaft aseptic nonunions associated with plating failure resulting from screw breakage were treated. The procedure involved skeletal traction in the femoral condyle, removal of the broken screws after making a bony window in the lateral cortex, with or without lengthening the femur, stabilization with a static locked nail, and finally, corticocancellous bone grafting. Postoperatively, ambulation with protected weight bearing was encouraged as early as possible.

RESULTS

All eight patients were followed up for at least 1 year (range, 1.1-4.7 years), and seven nonunions healed. The median union period was 4 months (range, 3-6 months). One patient had a persistent nonunion, and the locked nail broke at 6 months. The nonunion healed 4 months after closed revision with a new locked nail.

CONCLUSION

The described technique has both theoretical and clinical merits. All abnormalities can be corrected concomitantly. The success rate is high and the complication rate is low. Whenever possible, therefore, it may be used to treat all indicated cases of nonunion.

Transesophageal echocardiography in the anesthetic management of total hip arthroplasty

Total hip arthroplasty is a common procedure in the elderly and thromboembolism continues to be a cause of mortality and morbidity associated with this procedure. When properly diagnosed and treated the mortality rate from pulmonary embolism can be reduced significantly. Transesophageal echocardiograpic (TEE) detection of central pulmonary artery thromboemboli in patients with severe pulmonary embolism has been reported to have a sensitivity of 96.7% and a specificity of 88%. However TEE is not universally available due to its cost and expertise that is required. Taking into consideration its cost/effectiveness we suggest that in patients undergoing the cement type of total hip arthroplasty who are cardiopulmonary compromised, debilitated or elderly the use of TEE is indicated.

Alterations of myocardial ultrasonic tissue characterization by coronary angioplasty in patients with chronic stable coronary artery disease

We conducted a study to delineate the alterations in the cyclic changes of myocardial ultrasonic integrated backscatter (IBS) in patients receiving angioplasty for chronic coronary artery disease. Ultrasonic tissue characterization (UTC) and dobutamine stress echocardiography were performed in 43 patients before and 24 h after angioplasty, as well as before the follow-up angiography 3 months later. For segments being normokinetic with ischemic burden, the blunted amplitude and increased nadir deviation of IBS cyclic modulation recovered soon after angioplasty. For dyssynergic segments with contractile reserve, the angioplasty rebuilt the amplitude before the wall motion recovered, but corrected the nadir deviation tardily. In both circumstances, the coronary restenosis abolished the initial restoration. Those nonviable segments persistently revealed large deviations and small weighted amplitudes irrelevant to coronary lesions. The progress of myocardial ischemia, the development of wall motion dyssynergy and, then, the loss of viability, show different patterns of alterations in UTC after alleviating coronary obstructions.

Extra-articular deformity in distal radial fractures treated by external fixation

OBJECTIVE

To determine the radiographic outcome in fractures of the distal radius treated with closed reduction and external fixation.

DESIGN

A retrospective study.

SETTING

The orthopedic department of National Taiwan University Hospital.

PATIENTS

Eighty-five consecutive patients (36 female, 49 male), average age 48 years, with fractures of the distal radius seen between March 1995 and June 1998.

INTERVENTIONS

Closed reduction and external fixation of fractures, followed up by good-quality posteroanterior and lateral radiographs to evaluate healing.

MAIN OUTCOME MEASURES

Radial height, radial inclination and volar tilt were measured on radiographs obtained initially, immediately postoperatively and at the time of removal of external fixation. Data were analyzed by the t-test.

RESULTS

Immediately after reduction and fixation, there was a significant improvement in the measurements of radial height and radial inclination. This improvement was gradually lost and height and inclination were significantly decreased at the time the external fixation device was removed. External fixation did not improve the volar tilt.

CONCLUSION

External fixation is a popular method to improve the reduction of osseous deformity but cannot effectively protect comminuted distal radial fractures from loss of reduction, which may be associated with shortening and redisplacement.

Combined phototherapeutic keratectomy and therapeutic contact lens for recurrent erosions in bullous keratopathy

AIMS

To evaluate the therapeutic effects of excimer laser phototherapeutic keratectomy (PTK) combined with therapeutic contact lens for painful recurrent corneal erosions (RCE) secondary to bullous keratopathy (BK) not suitable for penetrating keratoplasty.

METHODS

Excimer laser PTK was performed prospectively in eight eyes with painful RCE due to BK visually expecting no benefit from penetrating keratoplasty. After mechanical removal of the epithelium, the corneas were ablated with 50 pulses in the central 6.5 mm zone (ablation rate 0.25 microm per pulse) and another 200 pulses for polishing the periphery. After PTK, therapeutic contact lenses were applied for 3 months. The mean follow up period after PTK was 10.9 months (ranging from 6 to 15 months).

RESULTS

All patients experienced relief of their pain symptoms after the epithelium healed. Only one patient complained of occasional stinging pain with intermittent recurrence of small bullae. He refused a second treatment because the pain was much less than that before the surgery and quite tolerable. No infection or other complications were noted.

CONCLUSION

PTK with deeper ablation and adjunctive therapeutic contact lens is an easy to perform and effective treatment with less recurrence rate for patients with BK and poor visual potential.

Tumor necrosis factor promoter polymorphisms in patients with rheumatoid arthritis in Taiwan

OBJECTIVE

To investigate the association of tumor necrosis factor (TNF) promoter polymorphisms with rheumatoid arthritis (RA) in Taiwan.

METHODS

TNF promoter polymorphisms at positions -238, -244, -308, -376, -857, and -863 were determined in 97 patients with RA and 97 healthy controls using the PCR-RFLP method.

RESULTS

The phenotypic frequency of TNF-308A was significantly lower in patients with RA than in healthy controls. This finding can only be found in HLA-DR4 negative patients, not in DR4 positive RA patients and controls. The TNF promoter polymorphisms at positions -238, -244, -308, -376, -857, and -863 were not related to the clinical manifestations of RA patients.

CONCLUSION

TNF-308A itself or a neighboring gene may be a protective factor for the development of RA in the HLA-DR4 negative population in Taiwan. TNF promoter polymorphisms were not associated with the clinical manifestations of patients with RA in Taiwan.

Microsatellite alterations in exfoliated cervical epithelia deoxyribonucleic acid as a marker for high-grade dysplasia

OBJECTIVE

The purpose of this study was to evaluate the feasibility of the use of deoxyribonucleic acid microsatellite alterations in cervical epithelia in the prediction of high-grade dysplasia and to compare it with a strategy based on human papillomavirus testing.

STUDY DESIGN

Our prospective study subjects were from a cohort of 498 women with minimally abnormal Papanicolaou test results including atypical squamous cells of undetermined significance and low-grade squamous intraepithelial lesion who had documented repeated Papanicolaou and human papillomavirus tests. Of these, 52 eligible patients having conizations or hysterectomies as their histologic outcomes were subjected to tests of loss of heterozygosity on a panel of 5 microsatellites (D3S1110, THRB, D3S1228, D6S291, D3S1289) within the deoxyribonucleic acid of exfoliated cervical epithelia. These genetic alterations were analyzed through fluorescence polymerase chain reaction by comparison of allele ratios of exfoliated cells with those of normal control tissue. Predictive values for high-grade cervical dysplasia and cancer between this deoxyribonucleic acid marker and human papillomavirus status were compared.

RESULTS

With the use of loss of heterozygosity in at least one locus for predicting high-grade cervical neoplastic lesion, the sensitivity, specificity, positive predictive value, and negative predictive value were 96.7%, 59.1%, 76.3%, and 92.9%, which were superior to those of the human papillomavirus test (80%, 59.1%, 72.7%, and 92.9%). As a triage for atypical squamous cells of undetermined significance, its sensitivity and negative predictive value were up to 100%.

CONCLUSION

The promising results on determining microsatellite alteration in dysplastic lesions might imply that it is possible to detect the earliest changes by potential molecular markers with exfoliated cervical epithelial cells.

Inhibition of nitric oxide synthesis accentuates blood pressure elevation in hyperinsulinemic rats

OBJECTIVES

To examine the role of endogenous nitric oxide (NO) in the pathogenesis of hypertension and insulin resistance in chronic hyperinsulinemic rats.

METHODS

Sustained hyperinsulinemia was achieved by insulin infusion (21.5 pmol/kg per min) via subcutaneous osmotic minipump for 6 weeks. NO synthase inhibitor, Nomega-nitro-L-arginine methyl ester (L-NAME, 5 mg/kg per day) was given orally after 4 weeks of vehicle or insulin infusion. The systolic blood pressure (SBP) was measured under conscious state by an electrosphygmomanometer before and after drug treatments.

RESULTS

Insulin infusion alone significantly increased SBP from 134 +/- 3 to 156 +/- 2 mmHg by week 4 and further to 158 +/- 3 mmHg by week 6 of insulin infusion. The insulin-infused rats had markedly decreased insulin sensitivity, as reflected by an elevated steady-state plasma glucose level estimated by the insulin suppression test. There were no significant differences in plasma glucose and triglyceride levels between rats with and without insulin infusion. When hypertension had been established in rats receiving insulin infusion for 4 weeks, superimposed L-NAME on insulin infusion for additional 2 weeks further increased SBP by 18 +/- 2 mmHg (from 157 +/- 2 to 175 +/- 2 mmHg). Plasma levels of NO metabolites (NOx) significantly decreased from 13.7 +/- 1.1 micromol/l during the control period to 6.1 +/- 0.6 micromol/l after 4 weeks of insulin infusion and further reduced to 4.1 +/- 0.5 micromol/l after combined infusion of L-NAME and insulin. L-NAME treatment alone for 2 weeks in control rats significantly increased SBP by 33 +/- 2 mmHg (from 133 +/- 2 to 166 +/- 2 mmHg) and plasma insulin levels, as a consequence of insulin resistance. Despite marked increases in blood pressure due to infusion of insulin alone or in combination with L-NAME, the sodium balance, urinary sodium and water excretions, water intake and body weight gain of insulin/L-NAME-treated rats were not significantly different from rats without insulin infusion.

CONCLUSIONS

Sustained hyperinsulinemia causes partial impairment of NO production that may contribute to the development of insulin resistance and hypertension. Additional inhibition of NO synthesis by L-NAME accentuates the blood pressure elevation and insulin resistance in hyperinsulinemic rats. Furthermore, a rightward shift of the renal arterial pressure-natriuretic function relationship occurred in this hypertensive model.

In vivo magnetic resonance (MR) study of fatty liver: importance of intracellular ultrastructural alteration for MR tissue parameters change

Fatty liver is thought to have a shorter T1 relaxation time than normal liver tissue, due to the accumulation of triglyceride. Previous studies regarding T1 and T2 relaxation times, however, show widely different results. In order to elucidate the mechanism responsible for the changes and diversity of relaxation times in fatty liver, we created two animal models in 14 rabbits, one acute form (N = 6) and the other chronic form (N = 8). Four rabbits were taken as a control group. Tissue relaxation times and the magnetization transfer (MT) effect of the liver tissue in these two models were measured. The results were correlated with biochemical analysis of water and fat content and histological examination, including findings in light microscopy and electron microscopy. Although the fatty ratio in both forms of fatty liver was similar, their tissue relaxation rate and MT effect were significantly different. The acute form showed prolongation of both T1 and T2 relaxation times (512 +/- 51 msec vs. 710 +/- 95 msec and 39 +/- 1.8 msec vs. 48 +/- 3.7 msec, respectively) and a decrease of the MT effect (50 +/- 5.1% vs. 38 +/- 6.3%), compared to those of the control group and preinduction liver. The chronic form showed shorter T1 and T2 values (526 +/- 36 msec vs. 406 +/- 56 msec and 36 +/- 1.6 msec vs. 33 +/- 2.3 msec, respectively) and a stronger MT effect (21 +/- 0.9% vs. 26 +/- 2.3%). In acute form fatty liver, electron microscopic examination revealed dramatic subcellular changes, such as vesicular transformation, a markedly increased amount of smooth endoplasmic reticulum (SER), and disruption of the crista. These changes were not found in the chronic form fatty liver. From this study, we concluded that the ultrastructural alteration in the subcellular organelles of hepatocyte might play a crucial role for the chameleonic presentation of MR tissue parameters in fatty liver.

Bilateral neurotrophic keratopathy complicating Vidian neurectomy

PURPOSE

To present a case of bilateral neurotrophic keratopathy with miosis after bilateral Vidian neurectomy for vasomotor rhinitis.

METHODS

Observational case report.

RESULTS

A 68 year-old man presented with irritation and blurred vision in both eyes 2 weeks after bilateral Vidian neurectomy. Slit-lamp examination revealed a large epithelial defect, typical of neurotrophic keratopathy, in the inferior two-thirds of cornea in both eyes. Corneal sensitivity test with a Cochet-Bonnet anesthesiometer and electrical study of the blink reflex indicated bilateral trigeminal dysfunction. Both pupils were miotic, and tests with hydroxyamphetamine 1% and epinephrine 0.1% showed postganglionic sympathetic nerve damage. The corneal epithelial defects healed after 2 months of treatment with systemic prednisolone, vitamin B(12) and tarsorrhaphy.

CONCLUSION

Neurotrophic keratopathy associated with dry eye syndrome may be a serious complication of Vidian neurectomy.

Accuracy of biphasic response, sustained improvement and worsening during dobutamine echocardiography in predicting recovery of resting myocardial dysfunction after revascularization: comparison with thallium-201 SPECT

To evaluate the accuracy of various types of wall motion response during dobutamine echocardiography (DE) in predicting functional recovery after revascularization, we studied 30 patients with stable coronary disease and left ventricular dysfunction by simultaneous DE and (201)Tl reinjection SPECT. Among 480 segments (16 segments/patient), 199 had abnormal wall motion at baseline and 167 were revascularized. The predictive value for recovery of function was 72% for a biphasic response, 61% for sustained improvement, 77% for worsening, and 27% for no change (p < 0.01 vs. each). Biphasic response had a sensitivity of 40% and specificity of 85%. Combining biphasic, sustained improvement and worsening responses, the sensitivity, specificity and accuracy were 76%, 65% and 71%, respectively. For (201)Tl SPECT, they were 90%, 65% and 78%, respectively. Thus, a biphasic response alone is of low sensitivity. Combination of biphasic, sustained improvement and worsening responses gives an accuracy rate comparable to that of (201)Tl reinjection SPECT in assessing functional recovery.

Effects of organosulfur compounds from garlic oil on the antioxidation system in rat liver and red blood cells

The modulation of garlic oil (GO) and three allyl compounds, diallyl sulfide (DAS), diallyl disulfide (DADS) and diallyl trisulfide (DATS), on the antioxidation system in rat livers and red blood cells was examined. Rats were orally administered GO (200 mg/kg body weight), DAS (20, 80 mg/kg body weight), DADS (80 mg/kg body weight) or DATS (70 mg/kg body weight) three times a week for 6 weeks. Control rats received corn oil (2 ml/kg body weight) alone. GO, DADS and DATS treatment significantly increased the glutathione (GSH) content (48-84%) in red blood cells (P < 0.05). DATS displayed a greater enhancement than GO and DADS (P < 0.05). Hemolysis induced by tert-butyl hydroperoxide was not suppressed by GO or allyl compound treatment although higher GSH content was evident. Hepatic GSH was not influenced by garlic components. In rat livers, DADS and DATS significantly increased the activity of GSH reductase (46 and 54%, respectively) and of GSH S-transferase (GST) (63 and 103%, respectively), but decreased the GSH peroxidase activity (27 and 28%, respectively). In contrast, GSH reductase and GST activities in the DAS group, either 20 or 80 mg/kg body weight, were similar to the control group. A decrease of GSH peroxidase activity was observed in rats dosed with 80 mg/kg body weight (P < 0.05). An increase in GST activity and a decrease in GSH peroxidase activities were also noted in GO-treated rats (P < 0.05). In red blood cells, three GSH-related antioxidant enzyme activities were not affected by garlic oil and its organosulfur components. Immunoblot assay showed that, accompanying the increase in hepatic GST activity, GO, DADS, DAS (80 mg/kg body weight) and DATS increased the expression of GST Ya, Yb1 and Yc proteins. Results indicate that GO and three allyl compounds play a differential role in modulation of the GSH-related antioxidant system in rat livers and red blood cells.

Effect of diallyl sulfide and diallyl disulfide, the active principles of garlic, on the aflatoxin B(1)-induced DNA damage in primary rat hepatocytes

The objective of this study was to investigate the effect of the active principles in garlic-- diallyl sulfide (DAS) and diallyl disulfide (DADS)--on aflatoxin B(1) (AFB(1))-induced DNA damage in primary rat hepatocytes. Primary rat hepatocytes, induced with DNA damage using 10 microM AFB(1) were used as an experimental model. According to the results of LDH leakage, 0.5 and 2 mM of DAS or 0.5 and 1 mM of DADS significantly increased the viability of hepatocytes compared with the AFB(1) controls after 4, 8 and 24 h treatment (P<0.05). According to the results of unscheduled DNA synthesis (UDS) test, 0.5 and 2 mM of DAS or 0.5 and 1 mM of DADS could significantly decrease the DNA damage induced by AFB(1) (P<0.05). Furthermore, 0.5 and 2 mM DAS or 0.5 and 1 mM DADS could increase the glutathione S-transferase (GST) and glutathione peroxidase (GPx) activities as compared with the AFB(1) controls after 24 h treatment (P<0.05). Results of immunoblot analysis of cytosolic GST isoenzyme indicate that the levels of GST isoform Ya, Yb2 and Yc were markedly increased after treatment with 0.5 and 2 mM DAS or 0.5 and 1 mM DADS compared with the AFB(1) control. These results indicate that 0.5 and 2 mM DAS or 0.5 and 1 mM DADS might protect hepatocytes from AFB(1)-induced DNA damage via increasing the activities of GST and GPx.

Intraventricular isovolumic relaxation flow patterns improve the predicting power of Doppler echocardiography for the left ventricular filling pressure in patients with anterior wall myocardial infarction

BACKGROUND AND PURPOSE

Previous studies have shown that left ventricular systolic asynchrony affects both the relaxation and filling phases of diastole. The purpose of this study was to delinate how the anterior wall dyssynergy influenced the intraventricular flow redistribution patterns during the isovolumic relaxation (IVR) period, which delineated the changes in diastolic suction performance and, therefore, determined the significant Doppler flow variables for predicting left ventricular filling pressure.

METHODS

Seventy-three patients with anterior wall myocardial infarction and dyssynergy were enrolled. Those who exhibited the whole IVR intraventricular flow redistributing toward the mitral apparatus, which indicated the reverse physiologic intraventricular pressure gradient in early diastole, were classified as group B, otherwise, as group A. The Doppler echocardiographic variables of mitral inflow were correlated with the left ventricular end-diastolic pressures (LVEDP).

RESULTS

With lower ejection fraction rate and more apical dyssynergy, the group B patients had much slower mitral flow propagation. For group A patients, the independent determinants for LVEDP were the ratio of mitral flow propagation rate to peak velocity in early diastole, the early mitral flow deceleration time and the IVR time, all occurring in early diastole. In contrast, the only independent determinant for LVEDP in group B patients was the ratio of mitral peak flow velocity in early diastole to that in late diastole.

CONCLUSIONS

The intraventricular IVR flow patterns could delineate how the left ventricular systolic dyssynergy influenced the diastolic process, and determine which echocardiographic variables were more useful for predicting LVEDP in patients with anterior wall myocardial infarction.

Exercise training activates large-conductance calcium-activated K(+) channels and enhances nitric oxide production in rat mesenteric artery and thoracic aorta

Exercise training has reversible beneficial effects on cardiovascular diseases, e.g. hypertension, which may result from a decrease in systemic vascular resistance. The purpose of this study was to investigate possible mechanisms associated with the changes in vascular reactivity in large and small arteries with vasoconstrictors and vasodilators in rats after exercise. Wistar-Kyoto rats were trained for 8 weeks (Ex group) on a treadmill and compared with sedentary counterparts (Sed group). After the measurement of blood pressure and heart rate at 8 weeks, rat mesenteric arteries and thoracic aortas were excised and prepared as rings for this study. In addition, special care was taken not to damage the endothelium of the preparations. Our results showed that exercise training for 8 weeks (1) not only prevented an increase in blood pressure but also caused a fall in heart rate, (2) attenuated the contractions induced by both prostaglandin F(2alpha) (PGF(2alpha)) and high K(+) in the mesenteric artery, but reduced the PGF(2alpha)-induced contraction in the aorta only, (3) enhanced the relaxation elicited by acetylcholine (ACh) in both mesenteric arteries and aortas, and (4) increased nitrate [an indicator of nitric oxide (NO) formation] in plasma. The enhancement of ACh-induced relaxation in the mesenteric arteries in the Ex group was suppressed by pretreatment with N(omega) -nitro-L-arginine methyl ester (L-NAME), tetraethylammonium (TEA; a nonselective inhibitor of K(+) channels) or charybdotoxin [CTX; a selective inhibitor of large-conductance calcium-activated K(+) (BK(Ca)) channels], whereas in the aorta that response was attenuated by TEA or CTX and almost completely abolished by L-NAME. However, with a combination of L-NAME plus CTX in the mesenteric artery, ACh-induced relaxation was completely abolished in the Sed group, but not in the Ex group. These results suggest that in addition to NO, activation of BK(Ca) channels in the vascular beds, at least in part, also contributes to vasodilatation in animals with exercise training.

An improved surgical technique to treat femoral shaft malunion: revised reamed intramedullary nailing technique

Twenty-four consecutive adult patients who sustained a femoral shaft angular or rotational deformity, with or without significant shortening, were treated with skeletal traction of the femoral condyle, transverse femoral osteotomy, realignment of the shaft axis with or without lengthening, stable reamed intramedullary nail stabilization, and corticocancellous bone grafting. Twenty-one patients who underwent the treatment were followed-up for at least 1 year (range 1.0-4.5 years), and all achieved a solid union. The union rate was 100% (21/21) with a union period of 4.9+/-0.5 months. There were no significant complications. All patients achieved a satisfactory outcome as indicated by patient satisfaction and physician assessment of outcome (p < 0.001, Fisher's exact test). In the present series, the use of this revised reamed nailing technique resulted in a high success rate and a low complication rate. It provides an effective alternative treatment in indicated cases.

Mamu-DQA1 allele and genotype frequencies in a randomly sampled breeding colony of rhesus macaques (Macaca mulatta)

We studied the allelic and genotypic distribution of the major histocompatibility class-II locus DQA1 observed in a random sample of Indian rhesus macaques (Macaca mulatta) from a major breeding facility in the United States. The DNA was isolated from whole blood samples collected between 1991 and 1994 from 65 Indian rhesus monkeys. Polymerase chain reaction-restriction fragment length polymorphism analysis (PCR-RFLP), which involves use of specific amplification of DQA1 exon 2 and subsequent restriction digestion of the 242-base pair fragment, was used to genotype the animals for the 20 known macaque (Mamu)-DQA1 alleles. Frequencies for four alleles (DQA1*240x, *2502, *2503 and *0102) differed significantly from those reported in a smaller sample of rhesus macaques from the German Primate Center. The modest genetic survey of Mamu-DQA1 genotypes presented here will be particularly useful in designing epidemiologic studies that investigate associations between immunogenetic background and disease susceptibility in macaque models of human disease.

Fibronectin attachment protein homologue mediates fibronectin binding by Mycobacterium avium subsp. paratuberculosis

Attachment of Mycobacterium avium subsp. paratuberculosis to host tissue and penetration of mucosal surfaces are pivotal events in the pathogenesis of Johne's disease. Fibronectin (FN) binding is required for attachment and internalization of several mycobacteria by epithelial cells in vitro. The objective of this study was to further characterize the FN binding activity of M. avium subsp. paratuberculosis. Although the bacteria bound FN poorly at pH above 7, brief acid pretreatment greatly enhanced FN binding within the pH range (3 to 10) studied. A 4.6-kbp fragment from an M. avium subsp. paratuberculosis genomic library was found to contain a 1,107-bp open reading frame that shows very high nucleotide sequence identity with that of the FN attachment protein (FAP) gene of M. avium subsp. avium. Pretreatment of FN with an FN-binding peptide from M. avium subsp. avium FAP abolished FN binding, indicating that M. avium subsp. paratuberculosis binds FN in a FAP-dependent manner. Pretreatment of M. avium subsp. paratuberculosis with anti-FAP immunoglobulin G did not abrogate FN binding; blocking occurred only when anti-FAP was added together with FN. FAP was detected by immunofluorescence only in lipid-extracted M. avium subsp. paratuberculosis. Western blotting and immunoelectron microscopy revealed that FAP is located near the interior of the cell envelope of M. avium subsp. paratuberculosis. The results indicate that a FAP homologue mediates the attachment of FN to M. avium subsp. paratuberculosis. Further, given the subcellular location of FAP, it is considered that this protein operates at the terminus of a coordinated FN binding system in the cell envelope of M. avium subsp. paratuberculosis.

Melatonin prevents endotoxin-induced circulatory failure in rats

The pineal secretory product melatonin was found to exert protective effects in septic shock. In a host infected by bacterial lipopolysaccharide (LPS), the expression and release of proinflammatory tumor necrosis factor-alpha (TNF-alpha) is rapidly increased, suggesting that TNF-alpha is associated with the etiology of endotoxic shock. Recent reports show that the expression of NO synthase (NOS) II and the production of superoxide anion (O2*-) also contribute to the pathophysiology of septic shock. In the present study we demonstrate that melatonin prevents circulatory failure in rats with endotoxemia and improves survival in mice treated with a lethal dose of LPS. The beneficial hemodynamic effects of melatonin in the endotoxemic animal appear to be associated with the inhibition of (i) the release of TNF-alpha in plasma, (ii) the expression of NOS II in liver, and (iii) the production of O2*- in aortae. In addition, the infiltration of polymorphonuclear neutrophils into the liver from the surviving LPS mice treated with melatonin was reduced. Thus, our results support the clinical use of melatonin in endotoxemia.

The promoter region of the CTLA4 gene is associated with type 1 diabetes mellitus

The CTLA4 (cytotoxic T lymphocyte associated antigen-4) gene encodes the T cell receptor involved in the control of T cell proliferation and mediates T cell apoptosis. C-T polymorphism is present at position -318 from the ATG start codon in the promoter region of the gene. We report a study on the polymorphism in 347 unrelated children with type 1 diabetes mellitus (DM) (age at diagnosis 7.2+/-3.8 years) and their 260 healthy siblings as controls. Genotype C/C conferred a risk of type 1 DM (RR = 2.02, 95% CI 1.32-3.10, pc = 0.0033). The gene frequency of the C allele was higher in patients (RR = 1.91, 95% CI 1.28-2.84, pc = 0.0026). The gene frequency and phenotype frequency of the T allele were negatively associated with type 1 DM (RR = 0.52, 95% CI 0.35-0.78, pc = 0.0026 and RR = 0.49, 95% CI 0.32-0.76, pc = 0.0022, respectively). The frequency of genotype C/T was lower in patients (RR = 0.50, 95% CI 0.32-0.78, pc = 0.0051). This study demonstrates that nucleotide -318 C-T polymorphism of the CTLA4 gene is associated with type 1 DM. The promoter allele -318 C confers a risk of type 1 DM but allele -318 T confers protection against this disease.