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Biomedical subjects

M F Chen

Publications and source records attributed to M F Chen.

At least 91 records · Page 5Linked to original sources

The effects of dyslipidemia on left ventricular systolic function in patients with stable angina pectoris.

Large-scale clinical trials have shown that long-term treatment with lipid-lowering therapy results in a significant reduction in the occurrence of heart failure among patients with coronary artery disease without previous evidence of congestive heart failure, suggesting dyslipidemia may have an adverse effect on left ventricular performance. To examine whether dyslipidemia has a detrimental effect on left ventricular systolic function and whether this effect is dependent on the corresponding severity of coronary atherosclerosis, 114 consecutive patients with stable angina and a positive exercise thallium-201 myocardial perfusion single-photon emission computed tomography were studied. All patients underwent measurement of serum lipid profiles, right-sided heart catheterization, left ventriculography, and selective coronary arteriography. Mean serum levels of total cholesterol and triglycerides were 4.5 and 1.4 mmol/l, respectively. In univariate analysis, a significant positive correlation between serum high-density lipoprotein (HDL) cholesterol and left ventricular ejection fraction (LVEF) (r = 0.49, P<0.0001) was found. Patients in the lower tertile of serum HDL cholesterol had a significantly lower mean LVEF than those in the upper tertile (55.9+/-15.2 vs. 72.8+/-6.8%, P<0.0001). Stepwise multiple linear regression analysis revealed that LVEF significantly correlated with HDL cholesterol (P<0.0001), the Gensini score (P = 0.008), and diabetes mellitus (P = 0.08) (r = 0.55, P<0.0001). In subgroup analysis of patients with angiographically normal coronary arteries, serum HDL cholesterol was still significantly associated with LVEF. The present study demonstrated an independent association between low HDL cholesterol and subclinical left ventricular systolic dysfunction in Chinese patients with stable angina whose serum levels of total cholesterol and triglycerides were relatively low. Moreover, this correlation remained significant even in patients with normal coronary angiograms, suggesting HDL cholesterol might influence left ventricular systolic performance through extra-atherosclerotic mechanisms.

Aged↗

The role of vitamin E on the anti-atherosclerotic effect of fish oil in diet-induced hypercholesterolemic rabbits.

The role of vitamin E on the anti-atherosclerotic effect of fish oil in diet-induced hypercholesterolemic rabbits was studied in male New Zealand white rabbits. The animals were randomly divided into six groups of 14 each according to the chow given them. Group I, control, rabbits were fed regular laboratory rabbit chow. In addition to the regular chow, Group II rabbits were fed a high (1%) cholesterol-enriched diet. Group III had the same diet as Group II plus 450 mg vitamin E/1000 g chow. Group IV also had the same diet as Group II plus 10% fish oil, but without vitamin E. Group V's diet contained 1% cholesterol, 10% fish oil, and 450 mg vitamin E/1000 g chow. Group VI had the same diet as Group V, but with 150 mg vitamin E/1000 g chow. At the end of a 6-week feeding, the ascending aorta from seven rabbits from each group was harvested for the analysis of prostanoid production, thiobarbituric acid reactive substances (TBARS), superoxide dismutase activity, and cholesterol and vitamin E levels; the same tissue from the other seven rabbits from each group was obtained for the delineation of atherosclerotic lesions by planimetry after the Sudan IV stain. The high cholesterol diet-treated rabbits had worse prostanoid synthesis and higher TBARS levels, which paralleled the severity of the atherosclerosis. Vitamin E or fish oil supplementation in a high cholesterol diet had beneficial prostanoid production, reduced aortic TBARS levels, and attenuated atherosclerotic lesions; these effects were potentiated when vitamin E and fish oil were combined together. The atherosclerotic lesion reduction in rabbits treated with high cholesterol plus fish oil and 450 mg vitamin E/1000 g chow reached statistical significance (P < 0.05) compared to high cholesterol and the same dose of vitamin E-treated rabbits. The rabbits treated with high cholesterol plus fish oil, but without vitamin E or with 150 mg vitamin E/1000 g chow showed an increased plasma creatine kinase activity at 4 (P < 0.01 and 0.05, respectively) and 6 (P < 0.001 and 0.01, respectively) week of feeding. These results suggest that vitamin E and/or fish oil attenuate atherosclerosis in high cholesterol-fed rabbits; vitamin E and fish oil potentiated the effect of each other. Furthermore, without sufficient vitamin E supplementation, rabbits treated with high cholesterol plus fish oil will show an elevation of plasma creatine kinase activity.

Animals↗

Low incidence of transplant coronary artery disease in Chinese heart recipients.

OBJECTIVES: This study sought to assess the incidence of transplant coronary artery disease (CAD) in Chinese heart recipients. BACKGROUND: The prevalence of transplant CAD detected by angiography at 1, 2 and 4 years after heart transplantation was 11%, 22% and 45%, respectively. The incidence of transplant CAD in Chinese heart recipients has not been reported. METHODS: For those recipients surviving for more than 1 year after transplantation, coronary angiography was performed annually for surveillance of transplant CAD. The recipient characteristics, donor characteristics, rejection episodes, medication and human leukocyte antigen (HLA) mismatches were recorded. RESULTS: Fifty patients were included in this study. Thirteen (26%) recipients had ischemic heart disease. Two patients (4%) had active cytomegalovirus (CMV) infection after transplantation. The mean number of rejection episodes in the 1st year after transplantation was 1.15. Among 47 patients with complete data of donor and recipient histocompatibility antigens, there were seven patients (14.9%) with two or fewer HLA mismatches. Among 74 angiograms of 50 patients reviewed, only one patient had discrete stenosis less than 50% in the middle portion of the left anterior descending artery at 1 year after transplantation. The cumulative incidence of transplant CAD was 2% at 1 year and 2% at 2 and 4 years after transplantation. CONCLUSIONS: The incidence of transplant CAD was low in Chinese heart transplant recipients. Low percentage of ischemic heart disease in recipients, low occurrence of active CMV infection and rejection episodes after transplantation, less racial disparity, and lower HLA mismatches may be the important factors.

Adolescent↗

Color Doppler ultrasound in benign and malignant breast tumors.

To study the flow indices of color Doppler ultrasound in the differentiation of malignant and benign breast tumors, data of 1124 female patients with breast lesions were analyzed. Of 1124 breast lesions, 590 (525%) were benign and 534 (47.5%) were malignant. Color Doppler scanning detected vascularity in 505 (85.6%) of benign lesions and 509 (95.3%) of malignant tumors. The tumors without detectable vascularization (1.9 +/- 0.1 cm) were significantly (p < 0.0001) smaller than the tumors with vascularization (2.7 +/- 0.1 cm). The age of the patients with malignant tumors was older than that of the patients with benign lesions. The size of malignant tumors was significantly larger than that of benign lesions. Significantly higher values of vessel number, resistance index (RI), pulsatility index (PI), and systolic peak flow velocity (Vmax) were found in carcinomas but the striking overlap of the values did not allow defining cutoff values which allow an accurate differentiation. Vmax did not correlate with the size of tumors. When tumors were grouped as T1 (2 cm or less), T2 (>2 cm, but not >5 cm), and T3 (>5 cm), the results were similar to those of all breast tumors. In conclusion, number of vessels, RI, PI, and Vmax do not provide accurate differentiation of benign and malignant tumors. However, average values of these flow indices of malignant tumors were significantly larger than those of benign lesions. Tumors with larger values of vessel number, RI, PI or Vmax require further studies to disclose the possibility of malignant tumors.

Adolescent↗

Value of magnetic resonance cholangiopancreatography in demonstrating major bile duct injuries following laparoscopic cholecystectomy.

BACKGROUND: Conventionally, recognition of bile duct injuries after laparoscopic cholecystectomy largely relies on endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic cholangiography (PTC). However, these invasive procedures are not without risk. Preliminary experience with use of magnetic resonance cholangiopancreatography (MRCP) to identify these injuries is reported. METHODS: The medical records of five patients who had undergone laparoscopic cholecystectomy and had suspected major bile duct injuries were reviewed. All five patients underwent MRCP, followed by conventional cholangiography: either ERCP or PTC, or both. The findings of MRCP and conventional cholangiography were compared. RESULTS: Four patients had proven bile duct injuries. The remaining patient had gallstones dislodged into the common bile duct (CBD) during laparoscopic cholecystectomy, which presented as transient jaundice mimicking a bile duct injury. The MRCP images were of higher diagnostic value than conventional cholangiographic images in four patients with frank bile duct injury. For these patients, ERCP showed only the cut-off sign of the CBD, and PTC was needed to visualize the upper biliary system. MRCP, however, demonstrated the entire biliary system proximal and distal to the amputated or stenotic sites simultaneously. In the remaining patient with dislodged gallstones, the two techniques yielded similar diagnostic information. CONCLUSION: This preliminary study suggests that MRCP is an ideal diagnostic test whenever bile duct injury following laparoscopic cholecystectomy is suspected.

Adult↗

Peripheral cholangiocarcinoma (cholangiocellular carcinoma): clinical features, diagnosis and treatment.

Peripheral cholangiocarcinoma is a relatively rare cancer. However, it is known to have an unfavourable prognosis compared with that of hepatocellular carcinoma. Little is known about its aetiology, clinical or pathological features. Recently, with the development of imaging modalities, early staged cholangiocarcinoma has been diagnosed with relative ease. Surgery is the optimal therapy. Total hepatectomy does not provide survival benefit. Conventional surgery remains the only effective treatment, even for patients with advanced-stage tumours. Factors influencing survival after hepatectomy were tumour-free margin, lymphnodes metastasis and histopathology of tumour. Palliative intrahepatic tubing or percutaneous transhepatic biliary drainage and brachytherapy can alleviate jaundice and cholangitis, thereby prolonging survival in some cases.

Bile Duct Neoplasms↗

The glandular component in congenital cystic adenomatoid malformation of the lung.

Although severe congenital cystic changes (CCC) of the lung may be fatal, less severe forms may regress or vanish spontaneously. With recent advances in sonography, asymptomatic CCC are increasingly found. Whether all CCC should be promptly excised, or not, is uncertain. Congenital cystic changes conceptually are bronchopulmonary foregut malformations (BPFM) with a predilection for malignant degeneration. Among all BPFM, congenital cystic adenomatoid malformation (CCAM) is most common. We therefore searched for evidence of early malignant transformation in five surgically excised and three autopsy lungs with CCAM. By light microscopy, CCAM resembled poorly formed and dilated bronchi, bronchioles and respiratory air spaces. Four lungs had multiple nodular aggregates of mucus producing cells; the glandular component (GC). By scanning electron microscopy, GC appeared as multiple micropolyps, resembling neuroepithelial bodies. By transmission electron microscopy, GC had a surface proliferation of cells with granules of the mucous type and a basal increase in cells with owl-eyed neuroendocrine granules. The glandular component in CCAM appeared similar to the mucous cells in hyperplastic polyps of the colon and a type of mucus producing bronchioloalveolar carcinoma. Our findings support the hypothesis that CCAM is caused by dysregulated paracrine growth of mature cells and extracellular matrices and that GC could have the potential for malignant transformation. Further clinical and laboratory studies of BPFM are needed for the appropriate management of congenital cystic changes.

Autopsy↗

Retroperitoneal laparostomy: an effective treatment of extensive intractable retroperitoneal abscess after blunt duodenal trauma.

BACKGROUND: Delay in surgical treatment and duodenal wound dehiscence are two major causes of extensive retroperitoneal abscess formation after blunt duodenal injury. This complication is traditionally treated with primary repair of the duodenal wound and drainage of the abscess through anterior laparotomy. Pyloric exclusion is sometimes added as an adjunctive procedure. The anterior approach, however, may result in inadequate drainage, and repeat surgery is sometimes needed. We reviewed our experiences and evaluated the effectiveness of retroperitoneal laparostomy for the treatment of retroperitoneal abscess with continuous soiling. METHODS: There were 52 blunt duodenal injuries during a 7-year period. Eleven patients developed extensive retroperitoneal abscesses. RESULTS: All 11 patients were treated with anterior laparotomy initially. Five patients recovered after this procedure. Six patients continued to have retroperitoneal abscesses and were under septic status. Two patients received another anterior drainage, and had recurrent abscesses later. Retroperitoneal laparostomy was performed for these six patients. After retroperitoneal laparostomy, daily wound care, and antibiotic treatment, all six patients recovered. Only two patients developed incisional hernia. CONCLUSION: Retroperitoneal laparostomy is effective in treating extensive intractable retroperitoneal abscess after blunt duodenal injury. Patients with the complications of duodenal leak and extensive retroperitoneal abscess should be treated with pyloric exclusion and drainage through anterior laparotomy first. If the duodenal wound does not heal after pyloric exclusion and retroperitoneal abscess persists, retroperitoneal laparostomy should be performed without further attempt to repair the wound.

Abdominal Abscess↗

Small bowel perforation: is urgent surgery necessary?

BACKGROUND: Controversies regarding how urgent bowel perforation should be diagnosed and treated exist in recent reports. The approach for early diagnosis is also debatable. The purposes of this study were to evaluate the relationship between treatment delay and outcome of small bowel perforation after blunt abdominal trauma and to determine the best assessment plan for the diagnosis of this injury. METHODS: One hundred eleven consecutive patients with small bowel perforations caused by blunt abdominal trauma were retrospectively reviewed. The patients were divided into four groups according to the time interval between injury and surgery. Hospital stay, time to resume oral intake, and mortality and morbidity rates were compared between groups. Physical signs, laboratory and computed tomographic findings, and the results of diagnostic peritoneal lavage were analyzed to find the most sensitive and specific test for early diagnosis of small bowel perforation. RESULTS: Delay in surgery for more than 24 hours did not significantly increase the mortality with modern method of treatment; however, complications increased dramatically. Hospital stay and time to resume oral intake increased significantly when surgery was delayed for more than 24 hours. Abdominal tenderness was a common finding, but it was not specific for bowel perforation. Only 40% of the computed tomographic scans were diagnostic for bowel perforations: 50% of them showed suggestive signs, and 10% were considered as negative. Persistence of abdominal signs indicated peritoneal lavage. By using cell count ratio in diagnostic peritoneal lavage and/or increased lavage amylase activity, presence of particulate matter and/or bacteria in the lavage fluid, all patients with intraperitoneal bowel perforation were diagnosed accurately before operation. CONCLUSION: Small bowel perforation has low mortality and complication rates if it is treated earlier than 24 hours after injury. The principle of "rushing to the operation suite" for a stable blunt abdominal trauma patients without detailed systemic examination is not justified. The priority of treatment for the small bowel perforation should be lower than the limb-threatening injuries. Diagnostic peritoneal lavage provides high sensitivity and specificity rates for the diagnosis of small bowel perforation if a specially designed positive criterion is applied.

Abdominal Injuries↗

Aminoguanidine attenuates hemodynamic and microcirculatory derangement in rat intestinal ischemia and reperfusion.

BACKGROUND: Nitric oxide (NO) participates in the regulation of hemodynamic and microcirculatory changes in intestinal ischemia and reperfusion (I/R). However, the nature of the involvement of an inducible NO release has been controversial. This study evaluates the impact of an inducible NO synthase inhibitor, aminoguanidine, used as a treatment in a rat intestinal I/R model. METHODS: We investigated the hemodynamics by measuring the mean arterial pressure (MAP), and the microcirculatory responses of the intestine and liver to systemically administered aminoguanidine by use of laser-Doppler flowmetry (LDF), in vivo microscopy, and flow cytometry. RESULTS: During the 30-min ischemia of the selected 20-cm ileal segment, no MAP change was noted. At reperfusion, a marked decrease of MAP was noted and the lowest levels were noted 3 hours after reperfusion (67 +/- 4% vs. 99 +/- 5% in sham-operated control animals). A marked decrease in liver perfusion as measured by LDF was noted 1 hour after reperfusion and remained low at 5 hours (72 +/- 4% vs. 97 +/- 3% in sham-operated control animals). A marked decrease in intestine perfusion was noted by using LDF 1 hour after reperfusion and remained low at 5 hours (43 +/- 3% vs. 92 +/- 4% in sham-operated control animals). The flow velocity of the postcapillary venules of the intestine was markedly decreased (1.01 +/- 0.62 vs. 2.67 +/- 0.34 mm/s in sham-operated control animals) at 5 hours after reperfusion. The flow velocity of the postsinusoidal venules of the liver was also markedly decreased (1.01 +/- 0.62% vs. 2.67 +/- 0.34% in sham-operated control animals). Leukocyte-endothelial interaction (adhesion) was increased in the postcapillary venules of the intestine (54 +/- 12 vs. 6 +/- 4/microm2 in sham-operated control animals) and in the postsinusoidal venules of the liver (32 +/- 8 vs. 2 +/- 2/microm2 in sham-operated control animals). Concomitantly, the granulocyte count was increased (9.1 +/- 0.6 vs. 2.1 +/- 0.3% of total circulating leukocytes in sham-operated control animals), with an increase of CD 11b expression. Aminoguanidine administration (1 mg/kg) 0.5 hour before ischemia and 1 hour after reperfusion significantly increased MAP, increased intestine and liver perfusion, decreased adhesion, and decreased circulating granulocytes and CD 11b expression. CONCLUSION: Inhibition of an inducible NO release by aminoguanidine in intestinal I/R can attenuate hemodynamic and microcirculatory derangement.

Animals↗

Prognosis in presumptive hypoxic-ischemic coma in nonneurologic trauma.

BACKGROUND: The neurologic outcome of comatose patients has a wide variation from complete reawakening to death. Methods of predicting the outcome of coma caused by either head injury or cardiac arrest have been the subject of much discussion in the literature. However, prediction of neurologic prognosis in comatose trauma patients without head injury has rarely been discussed. We reviewed our experience in treating patients with presumptive hypoxic-ischemic coma after trauma and tried to identify factors relating to their neurologic outcomes. METHODS: Thirty-six patients with normal brain computed tomographic scans, who remained comatose 10 minutes after stabilization of their hemodynamic status, were studied. Serial motor response, verbal response, pupillary light reflex, presence of spontaneous breathing and seizure, and blood glucose level were recorded to evaluate their roles in predicting neurologic outcomes. RESULTS: There were five deaths (mortality rate, 14%) and 11 patients (31%) with neurologic deficits. An absence of spontaneous breathing, a blood glucose level greater than 300 mg/dL during resuscitation, and a presence of seizure signified a poor prognosis. Initial neurologic evaluation at 10 minutes after stabilization of hemodynamic status was not accurate in predicting outcome. A motor response worse than withdrawal from painful stimuli at 24 hours after injury and an absence of pupillary light reflex at 48 hours after injury predicted a poor neurologic outcome, with a 100% accuracy rate. CONCLUSION: Hypoxic-ischemic coma in patients sustaining major trauma yielded a significantly better survival and neurologic outcome than that induced by cardiac arrest or head injury. Decision-making in the first 24 hours after injury should not be affected by the patient's neurologic status at that time. A motor response worse than withdrawal at 24 hours after injury and an absence of pupillary light reflex at 48 hours after injury predicted a poor neurologic outcome.

Adolescent↗

Neutrophil elastase inhibitor (ONO-5046) attenuates reperfusion-induced hepatic microcirculatory derangement, energy depletion and lipid peroxidation in rats.

UNLABELLED: Microcirculatory derangement, energy depletion, and lipid peroxidation are associated with the development of ischemia-reperfusion injury in the liver. This study investigated the effects of a neutrophil elastase inhibitor (ONO-5046) on hepatic ischemia-reperfusion injury. Adult, male Sprague-Dawley rats were divided into four treatment groups: 1) sham-operated control (laparotomy only, no ischemia) and saline injection (1 mL/kg), n = 6; 2) ischemia control (1-h ischemia, 2-h reperfusion) and saline injection (1 mL/kg), n = 6; 3) intravenous injection with ONO-5046 at a dose of 1 mg/kg 5 min before ischemia and immediately after reperfusion plus 1-h ischemia and 2-h reperfusion, n = 6; and 4) intravenous injection with ONO-5046 at a dose of 10 mg/kg 5 min before ischemia and immediately after reperfusion plus 1-h ischemia and 2-h reperfusion, n = 6. A laser-Doppler flowmeter and in vivo microscopy were used to investigate hepatic microcirculation. Tissue malondialdehyde (MDA) and adenosine triphosphate (ATP) levels were determined at the end of the experiment. RESULTS: Compared with ischemia alone, ONO-5046 significantly reduced the extent of microcirculatory and hemodynamic derangement after ischemia-reperfusion. ONO-5046 at both doses significantly attenuated decreases in mean arterial pressure. ONO-5046 lessened adherent leukocyte count and improved flow velocity in the sinusoids and postsinusoidal venules. ONO-5046 at the dose of 10m/kg reduced MDA (1.97 +/- 0.54 micromol/g protein vs. 3.58 +/- 1.21 micromol/g protein in the ischemia and reperfusion group) and increased ATP levels (2.62 +/- 0.19 micromol/g wet wt vs. 0.57 +/- 0.37 pmol/g wet wt in the ischemia and reperfusion group), whereas ONO-5046 at a smaller dose (1 mg/kg) had lesser but significant effects on MDA and ATP alterations. This study demonstrates that treatment with ONO-5046, a neutrophil elastase inhibitor, can ameliorate ischemia-reperfusion injury of the rat liver.

Adenosine Triphosphate↗

Anticonvulsant effect of Uncaria rhynchophylla (Miq) Jack. in rats with kainic acid-induced epileptic seizure.

This study investigated the anticonvulsant effect of Uncaria rhynchophylla (UR) and the physiological mechanisms of its action in rats. A total of 70 male Sprague-Dawley (SD) rats were selected for study. Thirty four of these rats were divided into 5 groups as follows: 1) CONTROL GROUP (n = 6): received intraperitoneal injection (i.p.) of kainic acid (KA, 12 mg/kg); 2) UR1000 group (n = 10), 3) UR500 group (n = 6) 4) UR250 group, received UR 1000, 500, 250 mg/kg i.p. 30 min prior to KA administration, respectively; 5) Contrast group: received carbamazepine 20 mg/kg i.p. 30 min prior to KA administration. Behavior and EEG were monitored from 15 min prior to drug administration to 3 hours after KA administration. The number of wet dog shakes were counted at 10 min intervals throughout the experimental course. The remaining 36 rats were used to measure the lipid peroxide level in the cerebral cortex one hour after KA administration. These rats were divided into 6 groups of 6 rats as follows: 1) Normal group: no treatment was given; 2) CONTROL GROUP: received KA (12 mg/kg) i.p.; 3) UR1000 group, 4) UR500 group, 5) UR250 group, received UR 1000, 500, 250 mg/kg i.p. 30 min prior to KA administration, respectively; 6) Contrast group: received carbamazepine 20 mg/kg i.p. 30 min prior to KA administration. Our results indicated that both UR 1000 and 500 mg/kg decreased the incidence of KA-induced wet dog shakes, no similar effect was observed in the UR 250 mg/kg and carbamazepine 20 mg/kg group. Treatment with UR 1000 mg/kg, 500 mg/kg, or 250 mg/kg and carbamazepine 20 mg/kg decreased KA-induced lipid peroxide level in the cerebral cortex and was dose-dependent. These findings suggest that the anticonvulsant effect of UR possibly results from its suppressive effect on lipid peroxidation in the brain.

Animals↗

Role of coronary angiography in myxoma patients: a 14-year experience in one medical center.

Cardiac myxoma is the most common form of primary heart tumor and often treated with surgical resection without a preoperative angiographic examination for fear of potential risk of sudden death. During the last 14 years, 24 of 38 patients with myxoma underwent coronary angiography. Coronary artery disease (CAD) and other abnormalities were found in 5. Our findings indicated that CAD is not uncommon among the myxoma patients, and coronary angiography should be performed preoperatively in all cases.

Adult↗

Human pulmonary acinar aplasia: reduction of transforming growth factor-beta ligands and receptors.

Pulmonary hypoplasia has been found in the human neonatal autopsy population and has been attributed to an alteration in epithelial-mesenchymal interactions during development of the lung. Pulmonary acinar aplasia is a very rare and severe form of pulmonary hypoplasia. The transforming growth factor-betas (TGF-beta) are multifunctional regulatory peptides that are secreted by a variety of normal and malignant cells and are expressed in developing organs including the lung; their tissue distribution patterns have possible significance for signaling roles in many epithelial-mesenchymal interactions. Here, we report our examination of TGF-beta in the lungs of a term female infant diagnosed with pulmonary acinar aplasia whose autopsy revealed extremely hypoplastic lungs with complete absence of alveolar ducts and alveoli. Immunohistochemical and in situ hybridization analyses were used to localize and measure the proteins and mRNA, respectively, for TGF-beta1, TGF-beta2, TGF-beta3, and TGF-beta type I and type II receptors (TGF-beta RI and RII) in formalin-fixed and paraffin-embedded sections of these hypoplastic lungs and normal lungs. Immunostaining for TGF-beta1, TGF-beta2, and TGF-beta RI and RII was significantly lower in the bronchial epithelium and muscle of the hypoplastic lungs than in normal lungs, whereas no difference was detected in staining for other proteins including Clara cell 10-kD protein, adrenomedullin, hepatocyte growth factor/scatter factor, and hepatocyte growth factor receptor/Met in the hypoplastic and normal lungs or in the liver and kidneys of this infant compared with normal liver and kidney. In addition, in situ hybridization showed that TGF-beta1 and TGF-beta RI transcripts were considerably reduced in the bronchial epithelium of the hypoplastic lung compared with normal lung. These results show that there is a selective reduction of TGF-beta in pulmonary acinar aplasia and suggest that the signaling action of TGF-beta in epithelial-mesenchymal interactions in the lungs of this developmental condition may be compromised.

Activin Receptors, Type I↗

Prospective sonographic study of 3093 breast tumors.

To evaluate the predictive ability of sonographic tumor characteristics to differentiate benign from malignant tumors, we examined 3093 breast tumors (2360 benign and 733 malignant tumors) with ultrasonography. The ratio of the longest dimension to the anteroposterior diameter of benign tumors was significantly larger than that of malignant tumors (1.88+/-0.1 versus 1.69+/-0.02, P < 0.0001). Shape, margins, echogenicity, internal echo pattern, retrotumor acoustic shadowing, compressibility, and microcalcification were significant factors in the logistic regression model. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of breast sonography for malignancy were 86.1, 66.1, 44.1, 93.9, and 70.8%, respectively. Biopsy of the tumor for pathologic diagnosis is recommended if sonographic features are suggestive of malignancy.

Adolescent↗