Acute and chronic effects of isosorbide-5-mononitrate administration on effective renal plasma flow and the renin-aldosterone system in cirrhotic patients

BACKGROUND AND AIMS

Isosorbide-5-mononitrate (ISMO) has been shown to be effective in reducing the risk of variceal bleeding in patients with cirrhosis. However, recent studies have suggested that this drug compromises renal function. The present study was conducted to assess the acute and chronic effects of ISMO on effective renal plasma flow (ERPF) and the renin-aldosterone profile in cirrhotic patients.

METHODS

Fifteen cirrhotic patients were included in the present study. The mean arterial pressure (MAP), heart rate (HR), serum renin concentration (SR), ERPF and plasma aldosterone concentration (PA) were checked before ISMO treatment (baseline study), after a single oral dose of 20 mg ISMO (acute effect study) and after 3 weeks of ISMO treatment (chronic effect study).

RESULTS

Our data showed that the oral administration of a single dose (20 mg) of ISMO to cirrhotic patients was associated with significant decreases in ERPF (from 405.18 to 369.06 mL/min) and MAP (from 93.26 to 86.40 mmHg), and increases in HR (from 65.53 to 70.06 beats/min), SR (from 24.15 to 54.41 pg/mL), and PA (from 105.1 to 148.7 pg/mL). However, no significant changes were observed in HR, MAP, PA, SR, or ERPF after 3 weeks of ISMO treatment when compared with the baseline study.

CONCLUSIONS

The administration of ISMO causes a decrease in ERPF in cirrhotic patients and its use in patients with renal impairment should be considered cautiously.

Transient increase in alveolar epithelial permeability induced by volatile anesthesia with isoflurane

Fifteen patients undergoing surgery and receiving volatile anesthesia with isoflurane were enrolled as the study group. At the same time, 15 patients undergoing surgery with intravenous anesthesia drugs were included as a control group to compare each other. Before surgery, 1 h after surgery, and 1 week after surgery, we investigated these two groups of patients with technetium-99m-labeled diethylene triamine pentaacetic acid radioaerosol inhalation lung scan (DTPA lung scan), a test to evaluate lung ventilation (LV), which was evaluated by the first and equilibrium lung ventilation image and alveolar epithelial permeability (AP) which was evaluated by the half time (T1/2, minutes) of Tc-99m DTPA radioaerosol lung clearance. No significant change and abnormality of LV before surgery, 1 h after surgery, or 1 week after surgery was found in either group of patients. In addition, no significant change in AP before surgery (T1/2 = 64.0 +/- 17.3 min), 1 h after surgery (64.5 +/- 19.6 min), or 1 week after surgery (63.6 +/- 17.6 min) was found among the control group patients (p values > 0.05). However, a significant transient increase in AP was found in the study group 1 h after surgery (71.7 +/- 17.5 versus 51.2 +/- 16.4 min), but it recovered 1 week after surgery (51.2 +/- 16.4 versus 70.9 +/- 16.0 min) (p values < 0.05). We conclude that volatile anesthesia with isoflurane can induce transient increase of AP.

Radionuclide esophageal transit test to detect esophageal disorders in patients with mitral valve prolapse

AIM

The origin of chest discomfort in patients with mitral valve prolapse (MVP) is controversial. Our aim was to prospectively determine the incidence of esophageal disorders in MVP patients with or without chest pain.

METHODS

Twenty-five MVP patients with chest pain (group A) and 25 MVP patients without chest pain (group B) underwent evaluation of esophageal motility. None of the total of 50 MVP patients had significant coronary artery disease on cardiac catheterization. Esophageal motility including esophageal mean transit time (MTT), residual fraction (RF), and retrograde index (RI) was analyzed by the radionuclide esophageal transit test (RETT).

RESULTS

In comparison with 25 age and sex-matched healthy volunteers, the results showed that: (1) 19 patients in group A (76%) had abnormal RETT findings (48% of cases with prolonged MTT, 44% of cases with higher RF, and 60% of cases with higher RI); (2) 3 patients in group B (12%) had abnormal RETT findings (8% of cases with prolonged MTT, 4% of cases with higher RF, and 8% of cases with higher RI). In addition, mean values of MTT, RF, and RI in group A patients were significantly higher than in group B patients and healthy volunteers.

CONCLUSION

We found that the chest pain in some MVP patients may be related to abnormal esophageal motility, based on the evidence from a simple and noninvasive RETT.

Monitoring the effect of anticoagulants on left atrial thrombi in patients with rheumatic heart disease: assessment with 111In-oxine-labelled platelet heart scintigraphy and transoesophageal echocardiography

111In-oxine-labelled platelet heart scintigraphy (In-plt) was used to evaluate the activity of left atrial thrombi detected by transoesophageal echocardiography (TEE) in 16 cases of rheumatic heart disease. The effect of anticoagulants on the therapeutic intervention of these patients was evaluated by In-plt and TEE. In-plt was performed in all patients in serial pre- and post-anticoagulant therapy studies with anterior, 45 degrees left anterior oblique and left lateral views taken daily from the second to sixth day after injection of labelled platelets. After discontinuing anticoagulants for at least 1 week, only nine cases of left atrial thrombi were detected among the 16 cases by initial In-plt. After anticoagulants were again used for at least 3 weeks, all nine positive cases became negative on repeat In-plt. These results suggest that the diagnostic sensitivity of In-plt is lower than that of TEE. However, In-plt is more suitable and useful for evaluating the activity of left atrial thrombi after antithrombotic agent therapy and for monitoring the effect of anticoagulant therapy on left atrial thrombi in patients with rheumatic heart disease.

A simple method for preparing radioactive capsules in colon transit study

Colon transit study is currently performed by delivering technetium-99m or indium-111 labelled activated charcoal to the colon in a methacrylate-coated capsule (coated capsule). However, the coating procedure is complicated and methacrylate has not been approved by the Food and Drug Administration. Therefore, a simpler method is needed for the clinical routine use of colon transit study. In this study, we used a commercial empty enteric capsule and a coated capsule for the measurement of colon transit time. We compared the in vitro stability and in vivo scintigraphy of 99mTc-labelled activated charcoal in the coated capsule and the enteric capsule to evaluate the possibility of clinical usage of the enteric capsule for colon transit time study. Activated charcoal powder was mixed with 49mTc-diethylene triamine pentaacetic acid (DTPA) and vaporized to dryness. The dry 99mTc-DTPA activated charcoal was loaded into the coated capsule and the enteric capsule. In vitro stability study was performed by immersing these capsules in a colourless buffer of variable pH which mimicked the conditions in the stomach and the small bowel. Capsule disruption was determined. Colon transit scintigraphy with 99mTc-DTPA charcoal was performed in five normal volunteers using these two capsules. The in vitro stability of these two types of capsule was similar and the colon transit scintigraphy findings were almost identical. Most capsules dissolved in the ascending colon and very few in the terminal ileum. It is concluded that enteric capsule is a suitable alternative to coated capsule for measurement of colon transit.

Cytokeratin fragment 19 and squamous cell carcinoma antigen for early prediction of recurrence of squamous cell lung carcinoma

Sixty patients with squamous cell carcinoma (SCC) of the lung, including 25 cases with recurrence and 35 cases without recurrence 1 year after operation, were enrolled in this study. The serial serum levels of cytokeratin fragment 19 (CYFRA 21-1) and SCC antigen were measured before operation and 1 week, 1 month, 3 months, 6 months, 9 months, and 12 months after operation for early detection of recurrence. The results revealed that 1) mean serum values of CYFRA 21-1 were significantly higher at early and any times after operation in 25 patients with recurrent SCC when compared with 35 patients without recurrent SCC; and 2) mean serum values of SCC antigen were significantly higher until 9 and 12 months after operation, in 25 patients with recurrent SCC when compared with 35 patients without recurrent SCC. We conclude that CYFRA 21-1 is a better marker than SCC antigen for early prediction of SCC recurrence in the lung.

Expression of mediated P-glycoprotein multidrug resistance related to Tc-99m MIBI scintimammography results

We prospectively studied a total of 24 patients with breast cancer to evaluate the relationship between the degree of accumulation of technetium-99m sestamibi (Tc-99m MIBI) and p-glycoprotein (Pgp) expression in tumor tissues. All 24 patients underwent Tc-99m MIBI scintimammography before surgery or biopsy. Immunohistochemical studies were performed on multiple non-consecutive sections of the same tumor using a Pgp specific monoclonal antibody, JSB-1. Planar images were started 10 min after injection of Tc-99m MIBI. Tumor to background (T/B) ratios calculated from the planar images were correlated with Pgp expression as determined by immunohistochemical studies. The T/B ratios were significantly lower for tumors in eight patients with positive Pgp expression (Group 1) than in 16 patients with negative expression (Group 2) (1.40+/-0.11 and 2.76+/-0.60, P<0. 05). Our data confirmed that Tc-99m MIBI scintimammography is useful for determination of the presence of multidrug resistance due to Pgp expression in patients with breast cancer.

Effects of single dose of 50mg captopril in patients with liver cirrhosis and ascites

BACKGROUND/AIMS

In patients with liver cirrhosis and ascites, the renin angiotensin system is usually activated. Such a correlation supports the hypothesis that activation of the renin-angiotensin system plays an influential role in the pathogenesis of ascites in liver cirrhosis.

METHODOLOGY

In this study, 25 patients with liver cirrhosis and ascites (10 females, 15 males; age: 45-67 years) were enrolled. We evaluated the acute effects of converting enzyme inhibitor (a single dose of 50 mg captopril taken orally) on glomerular filtration rate, effective renal plasma flow, filtration fraction, plasma renin activity, and plasma aldosterone.

RESULTS

Oral intake of a single 50 mg dose of captopril significantly decreased glomerular filtration rate (65 +/- 6 mL/min/1.73 m2 vs. 53 +/- 9 mL/min/1.73 m2), filtration fraction (21.2 +/- 2.7% vs. 15.5 +/- 4.1%), and plasma aldosterone (340 +/- 80 pg/mL vs. 247 +/- 42 pg/mL), but increased plasma renin activity (2.65 +/- 2.19 ng/mL/hr vs. 11.58 +/- 2.70 ng/mL/hr) and effective renal plasma flow (312 +/- 41 mL/min/1.73 vs. 356 +/- 60 mL/min/1.73 m2).

CONCLUSIONS

We suggest that oral intake of a single dose of 50 mg captopril can block the renin-angiotension system, and result in changes in renal hemodynamics and function in cirrhotic patients with ascites.

Technetium-99m tetrofosmin mammoscintigraphy findings related to the expression of P-glycoprotein mediated multidrug resistance

We studied 30 patients with infiltrating ductal breast carcinomas to evaluate the relationship between the degree of accumulation of technetium-99m tetrofosmin (Tc-TETRO) and p-glycoprotein (Pgp) expression in breast tumor tissues. All of the 30 patients underwent Tc-TETRO mammoscintigraphy to calculate breast tumor uptake of Tc-TETRO to background (T/B) ratios before surgery or biopsy. Immunohistochemical analysis was performed to determine Pgp expression in the pathological specimens of the 30 breast tumors. The T/B ratios were significantly lower for tumors in 12 patients with positive Pgp expression (Group A) than for those in 18 patients with negative expression (Group B) (1.20 +/- 0.12 and 1.94 +/- 0.30, p < 0.05). Our results supported the opinion that Tc-TETRO mammoscintigraphy is helpful for determining in vivo the presence of multidrug resistance due to Pgp expression in breast carcinoma patients.

The role of Tc-99m methoxyisobutylisonitrile scintimammography as compared to mammography in evaluating palpable breast masses of Taiwanese women

Eighty-one Taiwanese women (age range 31 to 79 years old) with palpable breast masses detected by mammography and or physical examination underwent technetium-99m methoxyisobutylisonitrile (Tc-99m-MIBI) scintimammography to assess its value in the detection of breast carcinomas and their differentiation from benign breast masses. The results showed that 58 of the 66 cases of breast carcinoma were detected by Tc-99m-MIBI scintimammography. Only 2 our of 15 patients with benign breast lesions had an abnormal scintimammographic finding. The mammography diagnosed 55 of the 66 cases of breast carcinoma, whilst 8 out of 15 patients with benign breast lesions had positive mammographic findings. The diagnostic sensitivity specificity and accuracy of Tc-99m-MIBI scintimammography were 88% 87% and 88%, respectively, whilst these parameters for mammography were 83%, 47% and 77%, respectively, regarding the differentiation of malignant from benign breast masses. We concluded that Tc-99m-MIBI scintimammography significantly improves the sensitivity and specificity for the detection of breast cancer in Taiwanese women with dense and small breasts.

Usefulness of technetium-99m tetrofosmin mammoscintigraphy as compared to mammography for detecting and differentiating palpable breast masses of young Taiwanese women

Sixty young Taiwanese women with palpable breast masses detected by mammography and/or physical examinations underwent technetium-99m tetrofosmin (Tc-TETRO) mammoscintigraphy to assess its value for detecting and differentiating breast masses. The results showed that 42 of the 45 cases of breast carcinoma were detected by Tc-TETRO mammoscintigraphy. Fourteen of the 15 o benign breast lesions were differentiated by Tc-TETRO mammoscintigraphy. The diagnostic sensitivity, specificity, positive predictive value negative predictive value and accuracy of Tc-TETRO mammoscintigraphy were 93% 93% 98% 82% and 93% respectively. Thirty-eight of the 45 cases of breast carcinoma were detected by mammography. Twelve of the 15 of benign breast lesions were differentiated by mammography. The diagnostic sensitivity, specificity, positive predictive value, negative predictive value and accuracy of mammography were 84% 80% 93% 63% and 83% respectively. We concluded that Tc-TETRO mammoscintigraphy when compared to mammography significantly improves the accuracy of detection and differentiation of breast cancer in Taiwanese women.

Comparison and discrepancy of 18F-2-deoxyglucose positron emission tomography and Tc-99m MDP bone scan to detect bone metastases

The purpose of this study was to evaluate the usefulness of positron emission tomography with 18F-2-deoxyglucose (FDG-PET) for the detection of malignant bone metastases, and to compare FDG-PET results with conventional technetium-99m methylene diophosphate (Tc-99m MDP) bone scan findings. Twenty-four patients (10 females, 14 males, ages: 39-71 years) with biopsy-proven malignancy and suspected bone metastases, underwent whole body FDG-PET and bone scan to detect bone metastases. Bone metastases were established in 39 discordant bone lesions by histopathological examination of biopsy samples, MRI/CT, and follow-up bone scan/FDG-PET findings showing progressively and extensively widespread bone lesions. A total of 98 bone lesions found on either FDG-PET or bone scan were evaluated For 39 bone lesions with discordant findings between FDG-PET and bone scan, histopathological examination, MRI/CT and follow-up bone scan/FDG-PET findings revealed 8 metastatic and 0 benign bone lesions with positive FDG-PET findings, not detected on bone scan. Eleven metastatic and 20 benign bone lesions with positive bone scan findings were not detected on FDG-PET. FDG-PET has a better specificity, but a lower sensitivity for detecting malignant bone metastases when compared with bone scan.

Recurrent hyperfunctioning parathyroid gland demonstrated on radionuclide imaging and an intraoperative gamma probe

Radionuclide imaging with Tc-99m MIBI is the preferred mode of parathyroid localization in current practice. It also successfully identifies hyperfunctioning autotransplanted parathyroid tissue. The authors report a case with recurrent hyperparathyroidism after total parathyroidectomy and autotransplantation in the forearm. Double-phase Tc-99m MIBI imaging successfully localized the hyperfunctioning parathyroid tissue, which was missed by magnetic resonance imaging and ultrasonography. In addition, the parathyroid tissue was localized using an intraoperative probe at subsequent surgery.

Expression of drug resistance protein related to Tc-99m MIBI breast imaging

Adjuvant and neoadjuvant chemotherapy is increasingly being used in the treatment of breast cancer patients. However, drug resistance plays an important role in chemotherapy failure in this cancer. The aim of this study was to determine the correlation between technetium-99m sestamibi (Tc-99m MIBI) breast imaging results and expression of the drug resistance proteins (p-glycoprotein (Pgp), Ki-67 and mutant p53) in human breast cancer tissues. Twenty-four breast cancer patients underwent Tc-99m MIBI breast imaging before surgery or biopsy. Protein expression was investigated by immunohistochemical studies on multiple nonconsecutive sections of surgery or biopsy samples. Tumor to background (T/B) ratios calculated by Tc-99m MIBI breast imaging were correlated with protein expression determined by immunohistochemical studies. The T/B ratios were significantly lower in 8 patients with positive Pgp expression (Group 1) when compared with 16 patients with negative Pgp expression (Group 2) (1.40 +/- 0.11 and 2.76 +/- 0.60, p < 0.05). However, the differences of T/B ratios between the patients with positive and negative Ki-67 mutant p53 expression were not significant. Our data confirmed that Tc-99m MIBI breast imaging is useful for determination of the presence of Pgp expression in breast cancer patients. No significant relationship between Tc-99m MIBI breast imaging results and Ki67/mutant p53 was found.

Evidence of impaired gallbladder function in patients with liver cirrhosis by quantitative radionuclide cholescintigraphy

OBJECTIVE

The aim of this study was to understand gallbladder function in liver cirrhosis.

METHODS

Gallbladder function was measured in 45 patients with liver cirrhosis by Tc-99m-labeled imino-diacetic acid analog cholescintigraphy. Gallbladder function was represented by the filling fraction and the ejection fraction (EF). The patients were divided into three groups, based on cirrhotic severity, using the modified Child's classification: A = good, B = fair, and C = poor. Fifteen normal control subjects were selected for comparison.

RESULTS

There were no significant differences in filling fraction among all of the study groups. Normal controls had significantly higher 60-min EF values than did liver cirrhosis patients. Among the liver cirrhosis patients, class A patients had the highest EF values, and class C patients had the lowest EF values.

CONCLUSIONS

We found that liver cirrhosis may significantly impair the gallbladder emptying, based on the evidence of quantitative Tc-99m-labeled imino-diacetic acid analog cholescintigraphy findings.

Tc-99m albumin scintigraphy to monitor the effect of treatment in protein-losing gastroenteropathy

PURPOSE

Tc-99m albumin scintigraphy is a noninvasive method for detecting protein-losing gastroenteropathy.

METHODS

Seven patients with protein-losing gastroenteropathy were evaluated with Tc-99m albumin scintigraphy. In addition, Tc-99m albumin scintigraphy was used to monitor the effect of treatment in five of these seven patients. The scintigraphic results were compared with serum albumin levels.

RESULTS

All seven patients had positive results in the pretreatment images. Changes in scintigraphic findings in the five treated patients correlated well with changes in serum albumin level.

CONCLUSION

Tc-99m albumin scintigraphy is useful not only for diagnosing protein-losing gastroenteropathy but also for monitoring the effect of treatment.

Lymphoscintigraphy using larger colloid particles may enhance visualization of the sentinel node in breast cancer: a case report

Lymphoscintigraphy along with a gamma-detecting probe has been applied successfully to breast cancer patients to localize the sentinel node during surgery, with a 5% false-negative rate. The authors report a case of stage II breast cancer. The sentinel node was not visualized on the initial lymphoscintigraphy with peritumoral injection of 37 MBq (1 mCi) 10 ml Tc-99m colloidal rhenium sulfide (Tc-99m ReS colloid; average particle size, 100 nm). However, the sentinel node was visualized in the left lateral view of the second lymphoscintigraphy with peritumoral injection of 37 MBq (1 mCi) 10 ml Tc-99m ReS colloid (average particle size, 500 nm). Lymphoscintigraphy using the larger colloid particles may enhance visualization of a sentinel node in breast cancer.

Quickly predicting chemotherapy response to paclitaxel-based therapy in non-small cell lung cancer by early technetium-99m methoxyisobutylisonitrile chest single-photon-emission computed tomography

The purpose of this study was to retrospectively predict the chemotherapy response to paclitaxel in non-small cell lung cancer (NSCLC) using technetium-99m methoxyisobutylisonitrile (Tc-99m MIBI) chest single-photon-emission computed tomography (SPECT) to detect the expression of multidrug-resistance-mediated Mr 170,000 P-glycoprotein. Before chemotherapy with Paclitaxel (Taxol), 30 patients with stage IIIb or IV NSCLC were enrolled in this study. Early chest SPECT 10 min after i.v. injection of Tc-99m MIBI was performed to qualitatively interpret Tc-99m MIBI chest SPECT visually and quantitatively calculate early tumor:normal lung ratios (T:NL) for quick assessment of multidrug-resistant P-glycoprotein expression in NSCLC. On the basis of qualitatively visual interpretation of early Tc-99m MIBI chest SPECT, all of 15 (100%) cases with good response to chemotherapy with Taxol could be detected but 10 (67%) of 15 cases with poor response could not be detected. Early Tc-99m MIBI chest SPECT could correctly predict chemotherapy response in 25 (83%) of 30 of cases. The early T:NL were 3.30 +/- 0.82 for 15 patients with good response and 2.02 +/- 0.19 for 5 patients with poor response. The differences were significant (P < 0.05) by independent Student t tests. However, no significant differences were found for other prognostic factors (age, sex, tumor size, tumor location, stage, and cell type) between good-response and poor-response patients. Early Tc-99m MIBI chest SPECT has the potential to predict chemotherapy response to Paclitaxel.

Simian virus 40 large T antigen binds a novel Bcl-2 homology domain 3-containing proapoptosis protein in the cytoplasm

A 193-kDa SV40 large T antigen (T-Ag)-binding protein, designated p193, was identified and cloned. Inspection of the deduced amino acid sequence revealed the presence of a short motif similar to the Bcl-2 homology (BH) domain 3, suggesting that p193 may be a member of a family of apoptosis promoting proteins containing only BH3 motifs. In support of this, p193 expression promoted apoptosis in NIH-3T3 cells. Deletion of the BH3 motif abolished p193 apoptosis activity. p193-induced apoptosis was antagonized by co-expression of Bcl-X(L). Immune cytologic analysis indicated that p193 is localized to the cytoplasm of transfected cells. p193-induced apoptosis was also antagonized by co-expression of T-Ag, which resulted in the cytoplasmic localization of both proteins. The p193 binding site was mapped to an N-terminal region of T-Ag previously implicated in transforming activity. These results suggest that T-Ag possesses an antiapoptosis activity, independent of p53 sequestration, which is actuated by T-Ag/p193 binding in the cytoplasm.

Age-related differences in the secretion of calcitonin in male rats

The mechanism of hypercalcitoninemia associated with aging was investigated in male rats. To mimic some of the hormonal changes with aging, orchidectomized (Orch) and hyperprolactinemic rats were used to mimic the physiological status of aging. Orch and haloperidol-induced hyperprolactinemic rats aged 3, 8, and 17 months were infused with CaCl2 and then bled from a jugular catheter following the CaCl2 challenge. Rat thyroid gland was incubated with Locke's medium at 37 degrees C for 30 minutes. Compared with 8- and 3-month-old rats, 17-month-old rats exhibited the lowest levels of plasma testosterone and the highest levels of plasma prolactin (PRL) and calcitonin (CT). The release of CT in the thyroid glands in vitro was highest in 17-month-old rats. Orchidectomy decreased rat plasma CT and thyroid CT release in vitro. Hyperprolactinemic rats had higher levels of plasma PRL and CT compared with control animals. The release of thyroid CT in vitro was greater in hyperprolactinemic rats. These results suggest that the hypersecretion of CT in 17-month-old rats may be due in part to hyperprolactinemia.

A comprehensive study on the blockage of thyroid and gastric uptakes of 188Re-perrhenate in endovascular irradiation using liquid-filled balloon to prevent restenosis

188Re-perrhenate has been reported effective in preventing restenosis after percutaneous transluminal coronary angioplasty. However, if the balloon ruptures, 188Re-perrhenate is released into the circulation, causing high radiation dosing to the thyroid and stomach. In this study, we evaluated the effects of perchlorate or iodide given at different times and in different ways for blocking the uptake of 188Re-perrhenate in the thyroid glands and the stomach to find the best method to apply clinically to reduce the radiation dose in case of balloon rupture. Sodium perchlorate, sodium iodide, or potassium iodide was given orally or intravenously to rats before, during, and after the injection of 188Re-perrhenate. The rats were sacrificed and we calculated the concentration of 188Re-perrhenate in various organs to evaluate the preblocking, mixed formula, and postblocking effects of perchlorate or iodide. Our data showed that the preblocking method effectively reduced the uptake of 188Re-perrhenate in both the thyroid and the stomach. The mixed formula method also demonstrated good blocking effect. The postblocking method showed obvious depression of thyroid uptake of perrhenate but its blocking effect on the stomach was not satisfactory.