Biomedical subjects

M M Lee

Publications and source records attributed to M M Lee.

At least 37 records · Page 2Linked to original sources

PubMed2000

Pre-incisional epidural ketamine, morphine and bupivacaine combined with epidural and general anaesthesia provides pre-emptive analgesia for upper abdominal surgery.

BACKGROUND: Previous studies have shown that N-methyl-D-asparate (NMDA) receptor antagonists provide a pre-emptive analgesic effect in humans. This study investigated the benefits of pre-emptive analgesia for upper abdominal surgery, using pre-incisional epidural ketamine + morphine + bupivacaine (K+M+B) treatment for achieving postoperative pain relief. METHODS: Sixty ASA 1-2 patients scheduled for upper abdominal surgery were allocated to three groups in a randomized, single-blinded study. Patients in the control group (I) received general anaesthesia followed by an infusion of normal saline. Group II and III patients received general anaesthesia with a continuous epidural infusion of 2% lidocaine. Thirty minutes after the incision in groups I and II, an epidural pain control regimen was administered using ketamine (10 mg) and morphine (1 mg) in 10 ml of 0.085% bupivacaine (K+M+B). Group III patients also received K+M+B, but it was administered 10 min after the 2% lidocaine injection and 30 min before skin incision. All patients received an epidural pain control regimen (q12 h) for 3 days after their first injection. Patient-controlled analgesia (PCA) with morphine was used to control subsequent postoperative pain. During the 3-day period following surgery, duration to PCA trigger (h), morphine consumption (mg), pain intensity at rest and when coughing/moving, and analgesic-related adverse effects were recorded. The VAS scale (0-10) was used to assess pain intensity. RESULTS: Median times to first PCA trigger were 1.2 (0.5-2.0) h, 3.0 (0.7-4.2) h, and 4.0 (2.5-7.5) h for groups I, II, and III, respectively. Both the incident and resting pain scores were consistently lower for group III patients than groups I and II. The number of PCA triggers (all attempts/successful triggers) during the day following surgery were 14.0 (3-30)/8.0 (3-24) times, 10.0 (3-23)/6.0 (2-20) times, and 7.0 (3-12)/4.5 (1-10) times for groups I, II, and III. Total morphine consumption for the 3-day observation period was 12.5 (3-42) mg, 10.5 (2-29) mg, and 6.0 (1-20) for groups I, II, and III, respectively. CONCLUSION: Pre-incisional epidural K+M+B treatment combined with continuous epidural anaesthesia and general anaesthesia provides an ideal pre-emptive analgesic therapy, exhibiting better postoperative pain relief than general anaesthesia and post-incisional K+M+B treatment.

Abdomen↗

PubMed2000

Differentiation between reversible and irreversible restrictive left ventricular filling patterns with the use of mitral annulus velocity.

A restrictive left ventricular filling pattern is generally recognized as an ominous prognostic sign in patients with congestive heart failure. Recently, this filling pattern has been further categorized into reversible and irreversible groups according to the changes in the mitral inflow pattern after preload reduction; furthermore, the prognosis is reported to be different for the two groups. Forty-two patients with a restrictive left ventricular filling pattern who could adequately perform Valsalva's maneuver were studied. Baseline peak early (E) and late (A) mitral inflow velocities, E/A ratio, deceleration time of E velocity, peak early (E') and late (A') diastolic mitral annulus velocities, and E'/A' ratio were obtained. During Valsalva's maneuver, the E/A ratio reversed (<1) in fifteen patients (15/42, 36%). These patients were categorized as belonging to the reversible group. Among the baseline mitral inflow and mitral annulus velocity parameters, A' > 0.05 m/s best discriminated between the reversible and irreversible restrictive left ventricular filling patterns, with a sensitivity of 80% and a specificity of 85%.

Adult↗

PubMed2000

Dietary fat and breast cancer.

One of the most often studied associations in epidemiology is dietary fat and breast cancer risk. That migrants from low-risk countries increase their risk on immigrating to higher-risk countries suggests that some modifiable lifestyle or environmental factor is responsible for the development of breast cancer. Although early international correlational studies and experimental animals studies support dietary fat as a risk factor for breast cancer, more recent data from case-control studies and cohort studies have been equivocal, thus the analytical data do not support a strong positive association. The conflicting results from analytic studies may be due to methodologic issues associated with study design, dietary assessment tools, measurement error, improper statistical analyses, and a lack of heterogeneity in fat intake among the study population. Moreover, current dietary questionnaires may be inadequate in capturing true dietary intakes or capturing the risk with exposure during earlier periods of a woman's life. Although two large clinical trials investigating the fat/breast cancer relationships issue are underway, researchers are generally skeptical at their ability to detect an independent association between fat and breast cancer risk. Further epidemiologic studies using current methodology may not prove to be fruitful in generating definitive answers to shed light on this controversial issue. In addition, rather than concentrating on dietary fat, researchers should focus on diets that are not only low in saturated fat, but also high in fruit and vegetable consumption. Researchers should take advantage of advances in molecular and genetic technology for a different perspective in examining the issue. For example, markers of susceptibility to breast cancer that can detect women at higher risk for breast cancer may be helpful in clarifying the role of dietary fat. More comprehensive and multiple approaches to studying dietary factors and breast cancer are recommended.

Age Factors↗

PubMed2000

Apoptosis and regulation of Bax and Bcl-X proteins during human neonatal vascular remodeling.

To verify that apoptosis is one of the possible mechanisms of neonatal vascular remodeling during the transition from fetal to neonatal circulation, we assayed for apoptosis and evaluated the expression of apoptosis-regulatory proteins in umbilical vessel versus ascending aorta, ductus arteriosus (DA) versus adjacent pulmonary artery and aorta, or aorta versus its branching arteries. Twenty-two umbilical cords (UCs), 6 DAs with adjacent aortas and pulmonary arteries, and 4 aortic arches with their branching great arteries were obtained from neonates. Smooth muscle cell (SMC) apoptosis in umbilical vessels was identified in all UCs. The expressions of Bax and Bcl-X were stronger in umbilical artery than in the neonatal aorta, but Bcl-2 was weak in both arteries in immunohistochemistry. In the immunoblot analysis of UCs, the expression of the proapoptotic short isoform of Bcl-X was stronger than in other tissue, and caspase-3 was selectively activated, whereas it was not in the other components of the cardiovascular system. In contrast, the expression patterns of the FasAg and Fas ligand were similar in umbilical artery and aorta. Regulation of Bcl-2 family proteins was also observed in other vascular sites at which SMCs undergo apoptosis on hemodynamic changes during birth, such as the DA and the branching points of the great arteries from the aortic arch. Apoptosis is involved in the regression of human umbilical vessels and the DA and in the remodeling of the branching great arteries during the neonatal period, when Bcl-2 family proteins are likely to play a key role.

Aorta↗

PubMed2000

Effects of methacholine and uridine 5'-triphosphate on tracheal mucus rheology in mice.

We compared the action of methacholine (MCh) and uridine 5'-triphosphate (UTP) with and without pretreatment with the chloride channel blocker 4,4'-diisothiocyano-2,2'-stilbenedisulfonate (DIDS) on the transepithelial potential difference (PD), the mucus collection rate (MCR), and tracheal mucus rheology using anesthetized C57BL/6 mice. The cystic fibrosis transmembrane conductance regulator (CFTR) blocker 5-nitro-2-(3-phenylpropylamino)benzoate (NPPB) was also used as a pretreatment for MCh. After collecting baseline mucus for 1.5 h, mucus secretion was stimulated by instilling 5 microl of 10(-2) M MCh or UTP around the upper trachea. There was a significant increase in PD after MCh or UTP stimulation (-21.3+/-2.0 mV MCh versus -14.1+/-1.6 mV control; -25.4+/-2.5 mV UTP versus -19.2+/-1.9 mV control). When UTP administration was preceded by DIDS, PD shifted from -15.2+/-2.9 to -12.0+/-2.2 mV. When MCh was preceded by DIDS or by NPPB, there was no change in PD. There was a significant decrease in mucus rigidity index, logG*, with MCh (2.54+/-0.09 versus 2.99+/-0.14 for control), similar to that previously reported in other species. With UTP, 14 of 16 mice responded in terms of PD becoming more negative, and of these, there was a significant difference in logG* after UTP administration (2.29 +/-0.10 versus 2.57+/-0.10 for control), whereas there was no change in logG* with DIDS administration before UTP. When DIDS administration preceded MCh, there was a diminished but still significant decrease in logG* from control, whereas there was no change in logG* when NPPB was preadministered. The control mucus collection rate was 0.19+/-0.09 mg/h, whereas after MCh stimulation, it increased to 2.83+/-0.78 mg/h. No significant difference was measured in the MCR after either UTP or DIDS+UTP stimulation. DIDS+MCh and NPPB+MCh both resulted in significant increases in MCR, but of a much smaller magnitude than that for MCh alone. We conclude that hypersecretion owing to UTP in C57BL/6 mice is less vigorous than with MCh, reflecting the limited population of Ca(2+)-dependent Cl(-) channels stimulated by UTP P(2) receptors. The action of MCh on tracheal mucus secretion in mice appears to involve both CFTR- and non-CFTR-dependent chloride channels.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗

PubMed2000

Transient prolonged stunning induced by dipyridamole and shown on 1- and 24-hour poststress 99mTc-MIBI gated SPECT.

UNLABELLED: We investigated whether poststress gated SPECT, which was believed to show resting wall motion, revealed stunning induced by dipyridamole stress. METHODS: In 62 patients with coronary artery disease (n = 57) or chest pain (n = 5), dipyridamole stress gated 99mTc-hexakis-2-methoxyisobutyl isonitrile (MIBI) SPECT and rest 201Tl SPECT were performed on the first day; 24-h delayed 201Tl SPECT and rest gated 99mTc-MIBI SPECT were performed on the second day. Stress and rest gated 99mTc-MIBI SPECT was performed 1 h after injection. The myocardium was divided into 17 segments, and perfusion was scored on a 4-point scoring system (scores, 0-3 for normal to defect); wall motion during first-day poststress gated and second-day rest gated SPECT was also scored on another 4-point scale (scores, 0-3 for normal to dyskinesia). RESULTS: Thirty-one of 62 patients showed wall motion abnormality that was worse after stress than during resting. Three hundred eight (29%) of the total 1054 segments showed wall motion abnormality on poststress gated SPECT. In 198 of these segments, wall motion abnormality was the same on poststress and rest gated SPECT, and 106 segments showed wall motion that was worse on 1-h poststress than on rest gated SPECT. Perfusion was normal either during rest (n = 113) or after a 24-h delay (n = 18) in 131 segments with the poststress wall motion abnormality. Of these 131 segments, 69 showed the same wall motion abnormality between poststress and resting periods (persistent stunning). However, in 40 segments, abnormal wall motion on 1-h poststress gated SPECT normalized on rest gated SPECT (transient prolonged stunning). The other 20 segments showed improvement of wall motion during rest compared with the poststress period but still showed abnormal wall motion during the resting period (between transient prolonged stunning and persistent stunning). Stress perfusion decrease was more severe in transient prolonged stunning than in persistent stunning. Poststress wall motion abnormality was more severe in persistent stunning. CONCLUSION: Using gated 99mTc-MIBI SPECT, stunned myocardium was found on 1-h poststress SPECT compared with normal resting wall motion found on rest gated SPECT on the next day. We conclude that some myocardial walls did not show true resting wall motion on 1-h poststress gated SPECT; hence, caution is necessary when using wall motion on 1-h poststress gated SPECT to assess resting wall motion.

Coronary Disease↗

PubMed2000

Limited incremental diagnostic values of attenuation-noncorrected gating and ungated attenuation correction to rest/stress myocardial perfusion SPECT in patients with an intermediate likelihood of coronary artery disease.

UNLABELLED: Either gated myocardial perfusion SPECT or attenuation-corrected SPECT can be used to improve specificity in the diagnosis of coronary artery disease (CAD). We investigated whether attenuation-noncorrected gating and ungated attenuation correction could improve the diagnostic performance of rest/stress perfusion SPECT in patients having an intermediate pretest likelihood of CAD. METHODS: Sixty-eight patients (29 men, 39 women; mean age, 59 +/- 12 y) with coronary artery stenosis > or =70% (1 vessel, n = 13; 2 vessels, n = 18; 3 vessels, n = 8; normal, n = 29) underwent rest attenuation-corrected 201TI SPECT and dipyridamole stress gated attenuation-corrected 99mTc-methoxyisobutyl isonitrile SPECT with an ADAC vertex camera. Three physicians graded the post-test likelihood of CAD for each arterial territory using a 5-point scale (1, normal; 2, possibly normal; 3, equivocal; 4, possibly abnormal; 5, abnormal). The sensitivity, specificity, and areas under receiver-operating-characteristic curves were compared for each operator by 3 methods: attenuation-noncorrected rest/stress SPECT, gated poststress SPECT plus attenuation-noncorrected rest/stress SPECT, and attenuation-corrected rest/stress SPECT plus gated poststress SPECT plus attenuation-noncorrected rest/stress SPECT. RESULTS: When higher than grade 3 was used as the criterion for CAD, no differences in sensitivity and specificity were found among the 3 methods for each operator. Areas under receiver-operating-characteristic curves for the diagnosis of CAD and stenosis revealed no differences for each modality (P > 0.05 for each comparison). CONCLUSION: In patients with an intermediate risk of CAD, viewing attenuation-noncorrected gated poststress SPECT and ungated attenuation-corrected rest/stress SPECT images did not improve the diagnostic performance for CAD and stenosis.

Coronary Circulation↗

PubMed2000

Postoperative intramuscular dextromethorphan injection provides pain relief and decreases opioid requirement after modified radical mastectomy.

BACKGROUND: Narcotics are still the therapeutic mainstay for postoperative pain relief. However, many unwanted side effects are accompanied. NMDA antagonists have been demonstrated to produce analgesic and antihyperalgesic effects, moreover, to possess potentiated effect of narcotics on postoperative pain management. AIMS: To examine whether postoperative dextromethorphan (DM), an antitussive and also an NMDA antagonist, intramuscular injection (I.M.) reduced pain and analgesic requirement after modified radical mastectomy (MRM). METHODS: Sixty-one patients scheduled for MRM were included and randomly allocated into two groups. For the control group (n=31), patients received chlorpheniramine maleate (CPM, 20 mg) I.M., while in the DM group (n = 30), 40 mg DM containing 20 mg CPM (I.M.) was given at the end of surgery. Meperidine (1 mg/kg, I.M.) was prescribed for postoperative pain relief, if ask. The time to first meperidine injection, total meperidine consumption, worst pain score, bed-rest time, and meperidine-related side effects were recorded for 48 hours postoperation. RESULTS: A longer time to first meperidine injection (20.3 +/- 1.4 vs 1.5 +/- 0.2 hr, p < 0.001) and lower meperidine consumption (10.7 +/- 4.0 vs 70.7 +/- 8.9 mg, p < 0.001) were observed in the DM group than the control group. The average bed rest time was significantly shorter in the DM group than in the control group (18.9 +/- 1.5 vs 23.4 +/- 1.6 hr, p < 0.001). The number of patients who required meperidine injection (6 vs 27, p < 0.005) and meperidine-related side effects were significantly lower in the DM group than in the control group (1 vs 7, p < 0.025). No difference was noted in worst VAS pain score between the DM and the study groups. CONCLUSION: Postoperative DM I.M. injection provided an analgesic effect and reduced meperidine requirement after MRM.

Analgesics, Opioid↗

PubMed1999

WEREWOLF, a MYB-related protein in Arabidopsis, is a position-dependent regulator of epidermal cell patterning.

The formation of the root epidermis of Arabidopsis provides a simple and elegant model for the analysis of cell patterning. A novel gene, WEREWOLF (WER), is described here that is required for position-dependent patterning of the epidermal cell types. The WER gene encodes a MYB-type protein and is preferentially expressed within cells destined to adopt the non-hair fate. Furthermore, WER is shown to regulate the position-dependent expression of the GLABRA2 homeobox gene, to interact with a bHLH protein, and to act in opposition to the CAPRICE MYB. These results suggest a simple model to explain the specification of the two root epidermal cell types, and they provide insight into the molecular mechanisms used to control cell patterning.

Amino Acid Sequence↗

PubMed1999

Phosphorylation of CREB in axon-induced Schwann cell proliferation.

Axonal contact regulates Schwann cell (SC) proliferation during development. However, the intracellular signal transduction pathways involved in the axon-induced proliferation of SC have not been described. We have previously shown that SC proliferation induced by axolemma-enriched fractions (AEF) is accompanied by increased expression of cyclic AMP-responsive element binding protein, CREB. We now report the AEF and dorsal root ganglion neuritic-induced signal transduction pathway(s) which regulate the phosphorylation of CREB that correlate with the SC proliferative response. The phosphorylated form of CREB was significantly increased after 16 hr of axonal stimulation, continued to increase for 48 hr, and subsequently decreased as monitored by immunocytochemistry and Western blot analysis. Treatment with protein kinase A (PKA) inhibitor, H89, completely abolished both the CREB activation and SC proliferation. In contrast, treatment with protein kinase C (PKC) inhibitor (bisindolylmaleimide) inhibited AEF-induced SC proliferation, but did not immediately affect CREB phosphorylation. These data are consistent with the view that PKA and PKC pathways are essential for AEF-induced SC proliferation. Since PKC can influence SC proliferation without initially affecting CREB phosphorylation, PKC may regulate SC proliferation at pathways distal to the immediate CREB activation.

Animals↗

PubMed1999

Diagnostic utility of Müllerian inhibiting substance determination in patients with primary and recurrent granulosa cell tumors.

OBJECTIVES: In this study we evaluated changes in serum Müllerian inhibiting substance (MIS) concentration in a large number of patients with granulosa cell tumors (GCT) to determine whether MIS is elevated at the time of presentation and whether MIS is an index of successful surgical resection and management of recurrences. METHODS: We retrospectively reviewed MIS levels from 17 subjects prior to tumor resection and studied serial MIS samples from 56 subjects following initial tumor resection. Clinical follow-up information was available for 36 of those with postoperative MIS values. Serum MIS was measured by an ELISA. MIS values were compared to a combination of normative values previously established in our laboratory and from more recently obtained samples from older pre- and postmenopausal women, using this assay. RESULTS: Serum MIS was elevated pre-operatively in 6 of 8 (75%) subjects with juvenile GCTs and in 7 of 9 (78%) of those with adult GCTs relative to age-matched controls (76% for both types combined). Post-operative clinical correlation was available for 36 patients. There was no clinical recurrence in 21 subjects with normal or undetectable postoperative values, and incompletely resectable tumor or recurrence was identified in 6 of 15 patients with elevated postoperative values. CONCLUSIONS: The results of this study demonstrate that postoperative serum MIS concentrations may be used to evaluate the completeness of tumor removal following initial surgery and that serial MIS determinations may allow the detection of recurrences.

Adolescent↗

PubMed1999

Effects of dextran on tracheal mucociliary velocity in dogs in vivo.

We have previously shown that dextran (molecular weight 4kDa) is a potential mucolytic agent, reducing the viscoelasticity and spinnability of cystic fibrosis (CF) sputum and improving its mucociliary clearability during in vitro testing. We wished to see whether low molecular weight (LMW) dextran had similar effects on mucus rheology when administered by aerosol to living dogs, and whether the administration of dextran increased the rate of mucociliary clearance. Healthy mongrel dogs were anesthetized with pentobarbital and intubated. After a 30-min Ringer aerosol delivery during spontaneous breathing, tracheal mucociliary velocity (TMV by charcoal marker particle transport) was measured under bronchoscopic control, and mucus for viscoelasticity analysis (magnetic rheometer) was collected by the endotracheal tube method. Then LMW dextran in Ringer vehicle was delivered by aerosol via the endotracheal tube, followed by the same procedures. We performed eight experiments in eight dogs, involving 30 min administrations of dextran aerosol; all dogs received inhalations of 20 mg/ml, 65 mg/ml, and 200 mg/ml dextran. Compared with Ringer control, TMV increased to 145% of control (P=0.0417) at 65 mg/ml dextran. Mucus viscoelasticity (G*) significantly decreased to 19% of control (P=0.0426) at 65 mg/ml. This in vivo study supports our previous in vitro testing, that LMW dextran decreases the mucus viscoelasticity and increases the rate of mucociliary clearance. We estimate the dosage received by aerosol at 65 mg/ml to be within the effective concentration range studied in vitro, i.e. 10-15 mg/ml final concentration. The results are consistent with the proposed mechanism that the saccharide moieties in LMW dextran compete for hydrogen bonding sites with other mucous glycoproteins. These new hydrogen bonds are structurally and rheologically ineffective, thus reducing the overall cross-link density, and making the mucus more easily cleared by ciliary and cough mechanisms.

Administration, Inhalation↗

PubMed1999

Preincisional dextromethorphan decreases postoperative pain and opioid requirement after modified radical mastectomy.

PURPOSE: To examine whether preincisional dextromethorphan (DM) improved analgesia after modified radical mastectomy (MRM). METHODS: Sixty patients (ASA I-II) scheduled for MRM were included and randomly allocated into two groups. Patients in the treatment group (DM) received 40 mg DM and 20 mg chlorpheniramine maleate (CPM) i.m., and those in the control group received 20 mg CPM i.m. alone 30 min before skin incision. Meperidine, 1 mg x kg(-1) i.m., was given for postoperative pain relief as required. The time to first meperidine injection, total meperidine consumption, worst pain score, bed-rest time, and side effects were recorded every 24 hr for 48 hr after surgery by a resident anesthesiologist on a double-blind basis. RESULTS: A longer time to first meperidine injection (19.2 +/- 1.6 vs 1.5 +/- 0.23 hr, P < 0.001) and lower meperidine consumption (0[10] vs 75[50] mg, median [interquartile range], P < 0.001) were observed in the DM group than in the control group. The bed-rest time was shorter in the DM than in the control group (18.0[4] vs 23.0[19] hr, P < 0.001). No difference was noted in worst VAS pain score. Meperidine-related side effects (nausea, vomiting, pruritus, dizziness, headache) were more frequent in the control (10/30) than in the DM group (3/30, P < 0.05). The number of patients who required meperidine injection for pain relief was lower in the DM (7/30) than in the control group (25/30, P < 0.005). No DM- or CPM-associated side effects were observed. CONCLUSION: Preincisional IM. DM treatment decreased postoperative pain and opioid requirement after MRM surgery.

Analgesics, Opioid↗

PubMed1999

Estimation of left ventricular end-diastolic pressure with the difference in pulmonary venous and mitral A durations is limited when mitral E and A waves are overlapped.

Previous studies showed that difference in pulmonary venous and mitral A-wave durations can be used for the estimation of left ventricular end-diastolic pressure, which is based on the assumption that the pulmonary venous A wave and mitral A wave start with the beginning of left atrial contraction. It is also assumed that the mitral A wave ends with the end of left atrial contraction. These assumptions may not be correct if left atrial contraction occurs before the early left ventricular filling is completed. Adequate Doppler mitral inflow and pulmonary venous flow signals were obtained simultaneously with left ventricular pressures at the cardiac catheterization laboratory in 50 patients who showed separated E and A waves in mitral inflow. After heart rate was increased by right atrial pacing to make the mitral E and A waves overlap, Doppler and hemodynamic measurements were repeated. When E and A waves are separated, pulmonary A-wave duration exceeding mitral A-wave duration has a sensitivity of 67% and specificity of 85% in the prediction of elevated left ventricular end-diastolic pressure (>/=20 mm Hg), whereas the pulmonary A wave ending later than mitral A wave has a sensitivity of 83% and a specificity of 45%. When the mitral E and A waves are overlapped, the pulmonary A wave ending later than mitral A wave is better for the prediction of elevated left ventricular end-diastolic pressure (sensitivity 55%, specificity 75%) than pulmonary A-wave duration exceeding mitral A-wave duration (sensitivity 9%, specificity 96%). However, overall, both methods are limited for clinical use.

Adult↗

PubMed1999

Expression of nuclear retinoid receptors in normal, premalignant and malignant gastric tissues determined by in situ hybridization.

Retinoids exhibit multiple functions through interaction with nuclear retinoid receptors and have growth-suppressive activity on gastric cancer cells. To better understand the roles of nuclear retinoid receptors during gastric carcinogenesis, we have used in situ hybridization to investigate expression of retinoic acid receptors (RARs) and retinoid x receptors (RXRs) in premalignant and malignant formalin-fixed paraffin-embedded gastric tissues. Histological sections of eight normal, 17 distal normal and nine gastric cancer tissues were hybridized with non-radioactive RNA probes for subtypes of RAR and RXR. Expression of RAR alpha, RAR beta, RAR gamma, RXR alpha and RXR beta was found in most cell types in gastric mucosa tissues from normal individuals as well as in distal normal tissues from cancer patients. Expression of RAR alpha and RAR beta were found in three and seven cancer tissues, respectively, and levels of RXR alpha mRNA were significantly decreased in poorly differentiated cancer tissues. Among the five investigated nuclear retinoid receptors, only expression of RAR alpha mRNA was significantly decreased in intestinal metaplasia, dysplasia and cancer tissues when compared to adjacent normal tissues. In conclusion, normal gastric mucosa expressed both RARs and RXRs, which supports the physiological role of retinoic acid on normal gastric mucosa. The decrease in RAR alpha expression in premalignant and malignant gastric tissues suggests a significant role of RAR alpha during gastric carcinogenesis.

Gastric Mucosa↗

PubMed1999

Social factors affecting interest in participating in a prostate cancer chemoprevention trial.

PURPOSE: A sample survey was conducted to assess the feasibility of recruiting participants, specifically African Americans, and to determine social factors influencing participation in a prostate cancer chemoprevention trial. METHODS: A convenience sample of adults visiting a hospital was identified and asked to participate in the survey. The survey included brief background information about prostate cancer and questions concerning four independent (age, marital status, race, insurance status) and three dependent (willingness to join a trial, involvement in long-term drug intake, interest in receiving more information) variables. RESULTS: The study analyzed 165 responses. Of the 165 respondents, 67% were African American. Marital status was a significant predictor of general willingness to participate (p = 0.047) for male respondents. No significant predictor was found for female respondents. Furthermore, for men, ethnicity/race showed a significant difference (30% white men vs 70% of minority men) for willingness to take the pills. CONCLUSION: The results suggest that African Americans are receptive to participating in chemopreventive trials. Thus, future studies exploring chemoprevention trials as an effective tool for reaching African Americans are warranted.

Black or African American↗

PubMed1999

Variant angina is not associated with angiotensin I converting enzyme gene polymorphism but rather with smoking.

BACKGROUND: Angiotensin converting enzyme (ACE) perhaps plays roles in regulating coronary vasomotor tone by producing angiotensin II and degrading bradykinin. OBJECTIVES: We sought to investigate the role of ACE gene polymorphism in the pathogenesis of variant angina and to compare it with that of other clinical risk factors for male patients with variant angina and age-matched and sex-matched control subjects. METHODS: We studied 78 male patients with variant angina who exhibited spontaneous or provoked coronary spasms during coronary angiography and compared prevalences of ACE gene genotype (deletion D and insertion I) and other risk factors between this group of patients with variant angina and age-matched and sex-matched control subjects whose angiograms were normal and in whom the ergonovine test did not cause spasms (n = 80). RESULTS: Smokers were more prevalent in the group of patients with variant angina (P < 0.05). Genotype and allele prevalences of the group of patients with variant angina (0.14, 0.53 and 0.33 for DD, DI and II and 0.41 and 0.59 for D and I, respectively) were no different from those of the control group (0.16, 0.49 and 0.35 for DD, DI and II and 0.40 and 0.60 for D and I). Multiple logistic regression analysis showed that smoking was a significant risk factor for variant angina (odds ratio 2.61, 95% confidence interval 1.03-6.66) whereas ACE genotype was not. CONCLUSIONS: Variant angina is associated with an environmental factor, such as smoking, rather than a genetic factor, such as ACE gene polymorphism.

Aged↗

PubMed1999

Müllerian-inhibiting substance type II receptor expression and function in purified rat Leydig cells.

Müllerian-inhibiting substance (MIS), a gonadal hormone in the transforming growth factor-beta superfamily, induces Müllerian duct involution during male sexual differentiation. Mice with null mutations of the MIS ligand or receptor develop Leydig cell hyperplasia and neoplasia in addition to retained Müllerian ducts, whereas MIS-overexpressing transgenic mice have decreased testosterone concentrations and Leydig cell numbers. We hypothesized that MIS directly modulates Leydig cell proliferation and differentiated function in the maturing testis. Therefore, highly purified rat Leydig and Sertoli cells were isolated to examine cell-specific expression, binding, and function of the MIS type II receptor. These studies revealed that this receptor is expressed abundantly in progenitor (21-day) and immature (35-day) Leydig cells as well as in Sertoli cells. Prepubertal progenitor Leydig cells exhibit high affinity (Kd = 15 nM), saturable binding of MIS. No binding, however, is detected with either peripubertal immature Leydig cells or Sertoli cells at either age. Moreover, progenitor, but not immature Leydig cells, respond to MIS by decreasing DNA synthesis. These data demonstrate that functional MIS type II receptors are expressed in progenitor Leydig cells and support the hypothesis that MIS has a direct role in the regulation of postnatal testicular development.

Animals↗