Short-term effect of apraclonidine on intraocular pressure in glaucoma patients receiving timolol and pilocarpine

Spinal epidural lipomatosis (SEL) is a condition in which excess adipose tissue is deposited circumferentially about the spinal cord in the epidural space. It is most frequently seen in patients on chronic glucocorticosteroid therapy for a variety of medical problems. This is a case report of lumbar epidural lipomatosis in a bodybuilder with radiculopathy supposedly induced by anabolic steroid intake.     

Topical SDZ GLC-756, a novel dopamine D-1 antagonist and D-2 agonist, lowers intraocular pressure in conscious rabbits

OBJECTIVE: To investigate the longitudinal changes in serum HIV RNA, and to clarify whether the viral load early in infection has a predictive value for the clinical outcome; also, to correlate viral phenotype at seroconversion and changes in CD4 cell counts with viral burden. DESIGN: Twenty seroconverters with HIV isolates available at seroconversion had HIV RNA quantified by polymerase chain reaction (PCR) at seroconversion and thereafter every 6 months. Mean follow-up time was 65 months. Patients were classified according to viral phenotype at seroconversion, time to AIDS progression, serum viral load within the first year (less or more than 1.5 x 10(4) copies/ml). RESULTS: High viral load at seroconversion was followed by a significant decline within the first months (P < 0.0005). Decline to < 1.5 x 10(4) copies/ml was correlated with slower progression to AIDS (P < 0.05). A correlation between the rate of CD4 decline and the median viral load during the ensuing viral load plateau phase was also shown (P < 0.05). Subsequent to this phase the viral burden increased. Rapid progressors had higher viral load than slow- or non-progressors; this was particularly pronounced late in infection. Harbouring syncytium-inducing (SI) virus at seroconversion was associated with faster progression to AIDS than non-SI (NSI; P < 0.005). The increased in vitro replication rate of SI over NSI was not translated into significantly higher serum HIV RNA. CONCLUSION: Serum HIV RNA is high around the time of seroconversion. A significant decline within the first months hereafter is followed by a plateau phase, which in turn is followed by an increase in HIV RNA. HIV RNA early in infection has a predictive value for the clinical outcome. The increased virulence of SI over NSI virus did not translate into significantly higher HIV RNA values.     

Effect of severing trigeminal nerve on intraocular pressure and pupil in rabbits

Changes of intraocular pressure (IOP) and pupil were observed through severing trigeminal nerve (TN), and the possible effect on TN on regulation of IOP was investigated in 5 rabbits. When TN was severed, the mean IOP at the same side was sharply and significantly elevated, being almost 2-fold of that before the procedure (P < 0.01). After the procedure, the mean elevated IOP decreased rapidly. The mean IOP at the end of the procedure was 0.28kPa higher than that before the procedure, and the IOP difference between pre- and post-procedure was not significant (P > 0.05). There was no significant difference in the comparison between the mean IOP after the procedure for 2 weeks and that before the procedure (P > 0.05). On the other hand, the mean diameter of pupils during and at the end of the procedure was significantly decreased (P < 0.01), when compared with that before the procedure, and afterward it gradually recovered. The above findings show that the rapid and significant reactions of IOP and pupil during the procedure are possibly affected by the actions of some neuropeptides in the TN5 suggesting that TN, participate in the regulation of IOP.     

The effects of unoprostone isopropyl 0.12% and timolol maleate 0.5% on diurnal intraocular pressure

PURPOSE: To compare the effect of unoprostone isopropyl 0.12% to that of timolol maleate 0.5% solution given twice daily on the diurnal curve of intraocular pressure (IOP) in patients with primary open-angle glaucoma or ocular hypertension. METHODS: In this investigator-masked, single-center, parallel-group comparison, 36 patients with primary open-angle glaucoma or ocular hypertension were randomized in a 2:1 ratio to receive either unoprostone isopropyl 0.12% or placebo/timolol maleate 0.5% solution, respectively. A placebo-controlled diurnal curve on day 0 and active-controlled diurnal curves at weeks 2 and 4 were performed at 0, 2, 4, 6, 8, 10, 12, and 24 hours. At week 2, administration of unoprostone isopropyl twice daily was compared with administration of timolol maleate twice daily. At week 4, administration of unoprostone isopropyl three times daily was compared with administration of timolol maleate twice daily. RESULTS: At the 24-hour 8:00 AM trough at week 2, administration of unoprostone isopropyl twice daily decreased IOP from 23.4 +/- 2.0 mmHg at baseline to 19.3 +/- 4.4 mmHg, and timolol maleate reduced IOP from 24.4 +/- 2.6 mmHg to 17.5 +/- 2.9 mmHg. At the 8:00 AM trough at week 4, unoprostone isopropyl given three times daily produced an IOP of 19.6 +/- 3.3 mmHg and timolol maleate resulted in an IOP of 19.4 +/- 3.0 mmHg. No statistical differences between groups were observed at any time point during either diurnal curve. Safety was similar in the two treatment groups, with no differences between groups in conjunctival hyperemia, anterior segment inflammation, or iris color change. CONCLUSION: Results of this short-term pilot trial indicate that unoprostone isopropyl may be safe and effective in reducing IOP from baseline when given twice or three times daily.     

Bioactivity and effect of a mixture of pilocarpine and lysine on the pupil and intraocular pressure in rabbits

In a prospective trial in 139 infants ASA classification I-II 13 observational items were scaled during the first postoperative hour (13 assessments). The items were drawn from the literature and chosen for economic purpose. Factor analyses (Principal component, Kaiser Criterion, Scree-test) were used for the elimination of useless items and for the identification of suitable ones. The discriminative properties of single items and different subsets of items to detect an analgetic demand were tested in discriminant analyses and variance analyses with repeated measurements. Due to insufficient variance four items had to be eliminated: "nasolabial folding", "colour of the face", "sweating of the head", and "muscle tone". The factor analysis if the remaining 9 items resulted in a one factorial solution. Neither the corrected item-scale-correlations nor the inter-item-correlations showed advantageous properties of single items compared with the others. For economic reasons two 5-item scales were chosen for further evaluation in regard to sensitivity, specify and validity. The items "crying", "facial expression", "positioning of the legs", "positioning of the trunc" and "motoric restlessness" built the Children's and Infants Postoperative Pain Scale (CHIPPS) whereas an Infants Postoperative Pain Scale (IPPS) contained the items "crying", "facial expression", "positioning of the arms", "positioning of the trunc" and "motoric restlessness". The latter five items had shown the highest factor loadings. The two systems had a high intern consistency with alpha > 0.90 (p < 0.01) with at least 73% explained variance. Inter-item-correlations and corrected item-scale-correlations showed no differences between the two scales. The discriminant analyses resulted in almost identic data for specify, sensitivity and predictive values of the IPPS compared with the CHIPPS. There was a significant interaction between repeated measurements and the supply of Piritramide and Ketamine, but not of Midazolam. Concurrent and constructive validation were positive for both systems, using administration of Piritramide as a criterion. For clinical purpose the CHIPPS should be preferred, because it has been proven to be valid in children up to 4 years of age and because controlled data on its sensitivity, specify, reliability and validity could already be presented.     

A monkey chair specially designed for ophthalmic examinations and intraocular pressure measurement in the conscious cynomolgus monkey

We constructed a monkey chair specially designed for ophthalmic examinations such as biomicroscopic examination, applanation tonometry etc. It was made of stainless steel and acrylic plastic, equipped with a protection plate for the experimenter, and adjustable to the size of the monkey. Using this chair, intraocular pressure (IOP) measurements of a fully conscious cynomolgus monkey were carried out at intervals of one or two hours from 10:00 AM to 10:00 PM. The IOP, at 6:00, 8:00 or 10:00 PM was compared with the IOP measured at the same time of the day after one or two weeks. The IOP while fully conscious showed diurnal variation (p < 0.001, ANOVA). The IOP measured at the same time of the day at one or two week intervals showed reasonable reproducibility.     

The ocular blood flow tonograph: a new instrument for the measurement of intraocular pressure in rabbits

OBJECTIVES: To determine the intraprostatic pathologic changes following accurately measured doses of transurethral microwave thermal energy in patients with benign prostatic hyperplasia. METHODS: Eight patients scheduled for prostate surgery were treated for approximately 1 hour without anesthesia using a newly designed microwave treatment catheter that allows a close impedance match to prostate tissue and concentrates thermal energy preferentially in the anterior and lateral prostate gland. Interstitial, urethral, and rectal temperatures were continuously measured using a novel stereotactic thermal mapping technique. Serial sections of prostate tissue harvested during subsequent surgery were evaluated pathologically with prostate mapping. RESULTS: Microwave treatment resulted in marked and continuous intraprostate temperature elevation, while urethral and rectal temperatures remained low. Peak intraprostate temperatures in individual patients reached as high as 80 degrees C. Mean temperature reached a maximum of 54 degrees C at a radial distance of approximately 0.5 cm from the urethra and remained 45 degrees C or higher up to a distance of 1.6 cm. The predominant pathologic findings were uniform hemorrhagic necrosis and tissue devitalization without significant inflammation. The mean distance from the urethra to the viable-necrotic tissue border was 1.6 +/- 0.2 cm (range, 0.5 to 2.5). At this border, no more than 1 mm in thickness, temperature averaged 45.7 +/- 0.6 degrees C, and there was a suggestion that pure stromal nodules were more resistant to thermal injury. CONCLUSIONS: Microwave treatment can destroy obstructive prostate tissue while maintaining innocuous urethral and rectal temperatures. Temperatures of 45 degrees C or higher for approximately 1 hour cause uniform thermoablation of prostate tissue.     

Evidence for a direct interaction between insulin receptor substrate-1 and Shc

Insulin receptor substrate-1 (IRS-1) and Shc are two proteins implicated in intracellular signal transduction. They are activated by an increasing number of extracellular signals, mediated by receptor tyrosine kinases, cytokine receptors, and G protein-coupled receptors. In this study we demonstrate that Shc interacts directly with IRS-1, using the yeast two-hybrid system and an in vitro interaction assay. Deletion analysis of the proteins to map the domains implicated in this interaction shows that the phosphotyrosine binding domain of Shc binds to the region of IRS-1 comprising amino acids 583-661. An in vitro association assay, performed with or without activation of tyrosine kinases, gives evidence that tyrosine phosphorylation of IRS-1 and Shc drastically improves the interaction. Site-directed mutagenesis on IRS-1 583-693 shows that the asparagine, but not the tyrosine residue of the N625GDY628motif domain, is implicated in the IRS-1-Shc-phosphotyrosine binding interaction. Mutation of another tyrosine residue, Tyr608, also induced a 40% decrease in the interaction. This study, describing a phosphotyrosine-dependent interaction between IRS-1 and Shc, suggests that this association might be important in signal transduction.     

The influence of RS-Timolol in comparison with R-Timolol and S-Timolol on the intraocular pressure in water-loaded rabbits

During gross anatomy dissection of the neck region, an anatomical variation of the ascending cervical artery was detected. Normally this artery is a branch of the inferior thyroid artery, which is a branch of the thyrocervical trunk. In our case, we found that the ascending cervical artery emerged from the superficial cervical artery, nearly 1 cm. lateral to the origin of this artery from the thyrocervical trunk.     

Plasma steroid concentrations in conscious and anesthetized rabbits

The ovarian steroids, estrogen, androgen, and progestin, were measured in the peripheral plasma of adult female rabbits that were either conscious or anesthetized with sodium pentobarbital (nembutal) or halothane. Concentrations of estrogen, androgens, and progestin were determined before and at 10 and 45 min after systemic injection of either buffer or LH. In the controls androgen levels were significantly different between animals anesthetized with nembutal and halothane. However, the greatest treatment effect was noted in plasma progestin concentrations which were significantly elevated in halothane-anesthetized animals in comparison to the conscious and nembutal-anesthetized animals. Following LH, the androgen and progestin levels were significantly elevated over basal levels. Most likely the treatment effect observed in the controls was still present but was overridden by the increased release of steroids following gonadotrophin stimulation. This study suggests that halothane, in contrast to nembutal, does significantly elevate peripheral progestin and androgen levels.     

Levobunolol 0.5% and timolol 0.5% to prevent intraocular pressure elevation after neodymium:YAG laser posterior capsulotomy

PURPOSE: To evaluate the prophylactic effect of levobunolol 0.5%, timolol 0.5%, or vehicle in reducing the incidence of postoperative intraocular pressure (IOP) spikes of 5 and 10 mm Hg or more in patients having neodymium:YAG (Nd:YAG) laser posterior capsulotomy. SETTING: Miami Vision Center, Coral Gables, Florida; Cullen Eye Institute, Baylor College of Medicine, Houston, Texas; Cincinnati Eye Institute, Cincinnati, Ohio; South Texas Cataract and Glaucoma Center, San Antonio, Texas; Mid-South Eye Foundation, Memphis, Tennessee, USA. METHODS: This prospective, double-masked, randomized study comprised 144 patients having Nd:YAG laser posterior capsulotomy in one eye. One drop of the test medication was administered preoperatively and one drop on the evening after surgery; IOP was measured preoperatively and 1,2,3 and 24 hours postoperatively. RESULTS: Intraocular pressure elevations of 5 mm Hg or more were seen in 1 of 60 patients (2%) in the levobunolol group, 4 of 54 (7%) in the timolol group, and 10 of 28 (36%) in the vehicle group. These elevations occurred significantly more frequently in the vehicle group than in the levobunolol (P < .001) or timolol (P < .004) groups. Elevations of 10 mm Hg or more were found in 2 of 28 patients (7%) treated with vehicle but were not observed in the patients treated with levobunolol or timolol. CONCLUSIONS: Levobunolol 0.5% or timolol 0.5% administered preoperatively and again in the evening after Nd:YAG laser capsulotomy effectively blunted the IOP rise that frequently follows laser surgery.     

Positive correlation between Tono-Pen intraocular pressure and central corneal thickness

OBJECTIVE: To examine the relationship between intraocular pressure (IOP) readings taken by the Tono-Pen tonometer (Mentor O&O, Norwell, MA) and central corneal thickness (CCT). DESIGN: Prospective cross-sectional population study. PARTICIPANTS: There were 651 eyes of 332 healthy subjects. MAIN OUTCOME MEASURES: A questionnaire was given to each subject requesting information on gender, age, race, and other factors that can influence IOP. The IOP then was measured using the Tono-Pen followed by measurements of CCT using an ultrasonic pachymeter. RESULTS: The IOP was found to increase by 2.9 mmHg/100 microns CCT in males and 1.2 mmHg/100 microns in females. For males, CCT was found to be statistically significant in predicting IOP (P < 0.001 in the right and left eyes) and diabetes was of borderline significance (P = 0.012 in the right eye, P = 0.089 in the left eye). For females, CCT was of borderline significance (P = 0.064 in the right eye, P = 0.019 in the left eye). In females, a family history of glaucoma (P = 0.021 in the right eye, P = 0.022 in the left eye) and hypertension (P = 0.010 in the right eye, P = < 0.001 in the left eye) were also significant in the prediction of IOP. Race was found to be a significant predictor of CCT (P < 0.001 in both right and left eyes) for both males and females. CONCLUSION: Clinicians should be aware that, as with the Goldmann applanation tonometer, the Tono-Pen has a systematic error in IOP readings caused by its dependence on CCT. Tono-Pen IOP readings are positively correlated to CCT in males and, to a lesser extent, in females as well. The CCT measurements should be considered to ensure proper interpretation of IOP measurements in the diagnosis and management of disorders in which the CCT or IOP readings are outside normal limits.     

Evidence for interaction between transmembrane segments in assembly of Kv1.3

Previously, we showed that the N-terminal recognition domain (T1) of Kv1.3 was not required for assembly of functional channels [Tu et al. (1996) J. Biol. Chem. 271, 18904-18911]. Moreover, specific Kv1.3 peptide fragments including regions of the central core are able to inhibit expression of current produced from a channel lacking the T1 domain, Kv1.3(T1-). To elucidate the mechanism whereby Kv1.3 peptide fragments suppress Kv1.3(T1-) current, we have studied the ability of peptide fragments containing the transmembrane segments S1, S1-S2, or S1-S2-S3 to physically associate with the Kv1.3(T1-) polypeptide subunit in vitro in microsomal membranes. Using c-myc (9E10) epitope-labeled peptide fragments and anti-myc antibody as well as antisera to the Kv1.3 C-terminus, we now demonstrate specific association of these peptide fragments with Kv1.3(T1-). Association of peptide fragments with Kv1.3(T1-) was correlated with integration of both proteins into the membrane. Furthermore, the relative strength and kinetics of this association directly correlated with the ability of fragments to suppress Kv1.3(T1-) current. The rate-limiting step in the sequential synthesis, integration, and formation of a complex was the association of integrated polypeptides within the plane of the lipid bilayer. These results strongly suggest that the physical association of transmembrane segments provides the basis for suppression of K+ channel function by K+ channel peptide fragments in vivo. Moreover, the S1-S2-S3 peptide fragment potently suppressed full-length Kv1.3, thus implicating a role for the S1-S2-S3 region of Kv1.3 in the assembly of the Kv1.3 channel. We refer to these putative association sites as IMA (intramembrane association) sites.     

Effect of motilin on gastrointestinal myoelectric activity in conscious rabbits

Gastrointestinal myoelectric activity was investigated in conscious rabbits with chronically implanted electrodes. As rabbit stomach is never empty, food was removed 1 h before the beginning of recordings. Propagated activity fronts spontaneously started in the jejunum without associated changes in the antroduodenal area. Intravenous administration of either motilin (600-1500 ng/kg) or erythromycin (5-50 micrograms/kg) did not modify antral activity, but simultaneously increased duodenal and jejunal activity in a dose-dependent manner. Spontaneous and induced jejunal activity fronts showed some similarities. However, those induced did not propagate and were not followed by a quiescence period. The effects of motilin (900 ng/kg) and erythromycin (25 micrograms/kg) were resistant to atropine (0.5 mg/kg), hexamethonium (2 mg/kg), or ondansetron (0.5 mg/kg). These results suggest that motilin is not a physiological modulator of the migrating myoelectric complex (MMC) in rabbits. Moreover, neither cholinergic nor 5-HT3 receptors are involved in either motilin or erythromycin-induced actions.     

Method for the determination of cerebral blood flow in conscious rabbits

A procedure for the determination of cerebral blood flow by the local clearance method after intracarotid injection of 133Xe in the conscious rabbit is described. The inert radioactive indicator is injected into a permanent nylon catheter equipped with a two-way Gordth's needle inserted into the common carotid artery and filled with heparin, emerging behind the shoulders of the animals. All branches of the homolateral common carotid artery except the internal carotid artery were ligated. Studies of the distribution of colored tracers (dark blue ink) and radioactive tracers (99mTc albumin microspheres) show that the main localization of the injected indicator is within the homolateral hemisphere. Brain to blood partition coefficients of 133Xe are worked out for rabbit's gray matter (0.576 +/- 0.048) and white matter (0.808 +/- 0.023). The slope method for first and second component of the wash-out Xenon curve is used for CBF calculations. CBF determinations in 9 normal rabbits result in 84.27 +/- 5.59 and 16.69 +/- 2.44 ml/min x 100 g tissue, respectively, for the fast and slow component. Significant changes do not occur in serial determinations within 2 hr.     

Central corneal thickness and intraocular pressure in a Mongolian population

OBJECTIVE: The purpose of the study was to quantify the variation of central corneal thickness (CCT) in an east Asian population and to examine its relationship to estimates of intraocular pressure (IOP) made with an applanation tonometer. DESIGN: The study design was a cross-sectional, population-based survey. PARTICIPANTS: One thousand two-hundred forty-two residents of H?vsg?l Province, Mongolia, 10 to 87 years of age participated. MAIN OUTCOME MEASURES: The CCT was measured using an optical pachymeter in all subjects. The IOP was measured using a, Goldmann-type applanation tonometer in subjects 40 years of age and older. RESULTS: There was a highly significant decrease in CCT with age: 5 microns/decade in men and 6 microns/decade in women (both, P < 0.0001). A highly significant positive correlation was identified between IOP and CCT. Linear regression analysis suggests that between the ages of 40 and 80 years, an increase in CCT of 10 microns is associated with an increase in IOP measurements of 0.18 mmHg in right eyes (95% confidence interval, 0.12-0.25) and 0.24 mmHg in left eyes (95% confidence interval, 0.17-0.31). The authors calculate that interindividual differences in CCT may produce a difference in measured IOP of between 2.3 and 3.1 mmHg. CONCLUSIONS: Variation in CCT is a significant source of variation in IOP measurements between individuals. The authors suggest that measurement of corneal thickness should be considered when assessing IOP as a risk factor for glaucoma in east Asians.     

The efficacy and safety of dorzolamide as adjunctive therapy to timolol maleate gellan solution in patients with elevated intraocular pressure. Additivity Study Group

OBJECTIVES: To investigate the incidence of rehardening of caries lesions in children in Southern China taking part in a preventive programme. DESIGN: Longitudinal study. SAMPLE AND METHODS: A prevention programme was established for 168 3-6-year-old children in a kindergarten (KG1), which included regular oral health education sessions and a daily toothbrushing exercise using fluoridated toothpaste (1000 ppm F). A group of 121 children studying in two other kindergartens without a preventive programme formed the controls. Due to lack of resources and dental personnel, restorative and other curative treatments were not provided. RESULTS: Rehardening of dentine caries (arrested caries) was found in children in both test and control groups. At the third annual examination, 45% of the caries lesions on the proximal surfaces of primary anterior teeth in KG1 children found at the baseline and previous annual examinations had become arrested. A multiple linear regression analysis indicated that baseline ds score and its interactions with the prevention programme, gender and the child's oral hygiene all had significant effect on the number of tooth surfaces with arrested caries at the third annual examination. CONCLUSION: Results from this study support the use of simple prevention programmes to stabilize the caries situation in communities where intensive use of trained dental personnel is not feasible.     

Evidence for an essential non-Watson-Crick interaction between the first and last nucleotides of a nuclear pre-mRNA intron

Nuclear pre-messenger RNA splicing requires the action of five small nuclear (sn) RNAs, U1, U2, U4, U5 and U6, and more than 50 proteins. The mechanistic similarity of nuclear pre-mRNA splicing and group II self-splicing suggests that many of the central processes of nuclear pre-mRNA splicing are based on RNA-RNA interaction. To understand the mechanism of pre-mRNA splicing, the interactions, and their temporal relationships, that occur between the snRNAs and the pre-mRNA during splicing must be identified. Several snRNA-snRNA and snRNA-intron interactions have been demonstrated but the putative RNA-based interactions that recognize the AG dinucleotide at the 3' splice site during 3' cleavage and exon ligation are unknown. We report here the reciprocal suppression between 5' and 3' splice site mutations in the yeast actin intron, and propose that the 3' splice site is positioned for 3' cleavage and exon ligation, at least in part, through a non-Watson-Crick interaction between the guanosines at the 5' and 3' splice sites.     

Evidence for an interaction between alpha-MSH and opioids in the regulation of gonadotropin secretion in man

BACKGROUND AND OBJECTIVES: The usefulness of testing for antibody to hepatitis B core antigen (anti-HBc) as a surrogate marker for non-A, non-B hepatitis can no longer be clearly established in the face of anti-hepatitis C virus testing. Application of anti-HBc testing in blood donors for detection of hepatitis B in addition to hepatitis B surface antigen testing (HbsAg) is a matter of debate. MATERIALS AND METHODS: We examined the serology and risk analysis data in a group of first-time blood donors. In 1.48% of 16,081 donors, anti-HBc reactivity was found. We invited a study group of 112 donors for extensive interviewing about the risk of blood transmissible diseases, and for serological testing. A control group of 240 first-time donors was studied as well. RESULTS: In the study group, the age was older (p < 0.001), a history of liver disease was more frequent (p < 0.001), and the donor (p < 0.001) or the donor's partner (p < 0.05) had either stayed longer in an HBV-endemic area or had been born in one. Combining these with the serological results, we found that strong anti-HBc reactivity was related to hepatitis B risk factors in HBsAg-negative donors. CONCLUSIONS: Anti-HBc testing in HbsAg-negative first-time donors makes it possible to identify hepatitis B risk factors with a prevalence of 0.02%. Our findings also stress the importance of including the history of the donor's partner(s) in the risk analysis before blood donation.     

Studies on intraocular inflammation produced by intravitreal human interleukins in rabbits

Preoperative evaluation of stenotic rectal tumors is important since they often involve adjacent organs and thus may require additional therapy. Previous reports on endosonographic staging have excluded stenotic tumors because they could not be fully visualized with the available equipment. In this study, we have evaluated the role of endosonography in staging stenotic rectal tumors, with special attention to the use of forward-looking endoprobes. Preoperative staging was performed in 28 patients with stenotic rectal tumors. Tumor extension was evaluated according to the TNM classification, and the results were compared with surgical and histopathologic findings. Endosonography accurately assessed tumor extension in two T2 tumors, 14 T3 tumors, and seven T4 tumors. Three T2 tumors were overstaged, and two T4 tumors were staged as T3. The accuracy was 82 percent. Twenty-two tumors were subject to histopathologic evaluation of lymph nodes. Lymph nodes larger than 1 cm had been seen by endosonography in eight patients, five of whom had nodal metastases. Lymph nodes smaller than 1 cm or no lymph nodes were found in 14 patients, four of whom had nodal metastases. In conclusion, full sonographic visualization of stenotic rectal tumors and thus evaluation of tumor extension can be achieved by using forward-looking endoprobes.