Renoprotective effects of carvedilol in hypertensive-stroke prone rats may involve inhibition of TGF beta expression.

1. The effect of carvedilol on renal function, structure and expression of TGF beta and the matrix proteins fibronectin, collagen I and collagen III, was evaluated in spontaneously hypertensive stroke-prone (SHR-SP) rats fed a high fat, high salt diet. 2. Carvedilol treatment for 11 to 18 weeks did not alter systolic blood pressure in SHR-SP rats, however, it resulted in a significant reduction in heart rate. 3. Carvedilol treatment reduced renal fibrosis and total, active and chronic renal damage to levels approaching those of WKY rats on a normal diet. 4. Urinary protein excretion was higher in SHR-SP rats (51+/-10 mg day(-1)) than WKY rats (18+/-2 mg day(-1)) and this was further increased when SHR-SP rats were fed a high fat, high salt diet (251+/-120 mg day(-1)). Treatment with carvedilol resulted in significantly lower urinary protein excretion (37+/-15 mg day(-1)). 5. The expression of TGF beta mRNA was significantly higher in SHR-SP rats compared to WKY rats and a further increase was observed when rats were fed a high fat, high salt diet. Renal TGF beta expression was significantly reduced by treatment with carvedilol. The expression of fibronectin and collagen I and collagen III mRNA showed a pattern similar to that observed with TGF beta mRNA expression. Collagen I mRNA expression followed a pattern similar to renal fibrosis. 6. These data indicate that carvedilol can provide significant renal protection in the absence of any antihypertensive activity and that the mechanisms involved in this action may include reduced expression of profibrotic factors such as TGF beta.

Immunohistochemical localization of H-K-ATPase alpha(2c)-subunit in rabbit kidney.

The rabbit kidney possesses mRNA for the H-K-ATPase alpha(1)-subunit (HKalpha(1)) and two splice variants of the H-K-ATPase alpha(2)-subunit (HKalpha(2)). The purpose of this study was to determine the specific distribution of one of these, the H-K-ATPase alpha(2c)-subunit isoform (HKalpha(2c)), in rabbit kidney by immunohistochemistry. Chicken polyclonal antibodies against a peptide based on the NH(2) terminus of HKalpha(2c) were used to detect HKalpha(2c) immunoreactivity in tissue sections. Immunohistochemical localization of HKalpha(2c) revealed intense apical immunoreactivity in a subpopulation of cells in the connecting segment, cortical collecting duct, and outer medullary collecting duct in both the outer and inner stripe. An additional population of cells exhibited a thin apical band of immunolabel. Immunohistochemical colocalization of HKalpha(2c) with carbonic anhydrase II, the Cl(-)/HCO exchanger AE1, and HKalpha(1) indicated that both type A and type B intercalated cells possessed intense apical HKalpha(2c) immunoreactivity, whereas principal cells and connecting segment cells had only a thin apical band of HKalpha(2c). Labeled cells were evident through the middle third of the inner medullary collecting duct in the majority of animals. Immunolabel was also present in papillary surface epithelial cells, cells in the cortical thick ascending limb of Henle's loop (cTAL), and the macula densa. Thus in the rabbit kidney, apical HKalpha(2c) is present and may contribute to acid secretion or potassium uptake throughout the connecting segment and collecting duct in both type A and type B intercalated cells, principal cells, and connecting segment cells, as well as in cells in papillary surface epithelium, cTAL, and macula densa.

Eprosartan reduces cardiac hypertrophy, protects heart and kidney, and prevents early mortality in severely hypertensive stroke-prone rats.

OBJECTIVE: Eprosartan is a selective angiotensin II type I receptor antagonist approved for the treatment of hypertension. In the present studies, eprosartan's ability to provide end-organ protection was evaluated in a model of cardiomyopathy and renal failure in stroke-prone rats (SP). METHODS: SP were fed a high fat (24.5% in food) and high salt (1% in water) diet (SFD). Eprosartan (60 mg/kg/day) or vehicle (saline control) (n = 25/group) was administered by intraperitoneally-implanted minipumps to these SP on the SFD for 12 weeks. Normal diet fed SP and WKY rats (n = 25/group) were also included for comparison (i.e. served as normal controls). Mortality, hemodynamics, and both renal and cardiac function and histopathology were monitored in all treatment groups. RESULTS: Eprosartan decreased the severely elevated arterial pressure (-12%; P < 0.05) produced by SFD but did not affect heart rate. Vehicle-treated SP-SFD control rats exhibited significant weight loss (-13%; P < 0.05) and marked mortality (50% by week 6 and 95% by week 9; P < 0.01). Eprosartan-treated SP-SFD rats maintained normal weight, and exhibited zero mortality at week 12 and beyond. Eprosartan prevented the increased urinary protein excretion (P < 0.05) that was observed in vehicle-treated SP-SFD rats. Echocardiographic (i.e. 2-D guided M-mode) evaluation indicated that SP-SFD vehicle control rats exhibited increased septal (+22.2%) and posterior left ventricular wall (+30.0%) thickness, and decreased left ventricular chamber diameter (-15.9%), chamber volume (-32.7%), stroke volume (-48.7%) and ejection fraction (-22.3%), and a remarkable decrease in cardiac output (-59.3%) compared to controls (all P < 0.05). These same parameters in eprosartan-treated SP-SFD rats were normal and differed markedly and consistently from vehicle-treated SP-SFD rats (i.e. treatment prevented pathology; all P < 0.05). Cardiac-gated MRI data confirmed the ability of eprosartan to prevent cardiac pathology/remodeling (P < 0.05). Histopathological analysis of hearts and kidneys indicated that eprosartan treatment significantly reduced end-organ damage (P < 0.01) and provided corroborative evidence that eprosartan reduced remodeling of these organs. Vehicle-treated SP-SFD rats exhibited a 40% increase in the plasma level of pro-atrial natiuretic factor that was reduced to normal by eprosartan (P < 0.05). CONCLUSION: These data demonstrate that eprosartan, at a clinically relevant dose, provides significant end-organ protection in the severely hypertensive stroke-prone rat. It preserves cardiac and renal structural integrity, reduces cardiac hypertrophy and indices of heart failure, maintains normal function of the heart and kidneys, and eliminates premature mortality due to hypertension-induced end-organ failure.

Differential global gene expression in red and white skeletal muscle.

The differences in gene expression among the fiber types of skeletal muscle have long fascinated scientists, but for the most part, previous experiments have only reported differences of one or two genes at a time. The evolving technology of global mRNA expression analysis was employed to determine the potential differential expression of approximately 3,000 mRNAs between the white quad (white muscle) and the red soleus muscle (mixed red muscle) of female ICR mice (30-35 g). Microarray analysis identified 49 mRNA sequences that were differentially expressed between white and mixed red skeletal muscle, including newly identified differential expressions between muscle types. For example, the current findings increase the number of known, differentially expressed mRNAs for transcription factors/coregulators by nine and signaling proteins by three. The expanding knowledge of the diversity of mRNA expression between white and mixed red muscle suggests that there could be quite a complex regulation of phenotype between muscles of different fiber types.

A randomized controlled study of the use of transscleral diode laser and cryotherapy in the management of rhegmatogenous retinal detachment.

PURPOSE: Cryotherapy, the most common modality used to create a chorioretinal adhesion during retinal reattachment surgery, is associated with the dispersion of viable pigment epithelial cells and breakdown of the blood-ocular barrier, which are thought to be causative in a number of postoperative events, including macular pucker, proliferative vitreoretinopathy (PVR), and cystoid macular edema. Transscleral diode laser has been used successfully to create a chorioretinal adhesion in retinal reattachment surgery (diopexy) and experimentally has been shown to cause less pigment dispersion and blood-ocular barrier breakdown than cryotherapy. The authors carried out a prospective randomized study to compare the results and complication rates of transscleral diopexy with those of cryopexy during surgery for rhegmatogenous retinal detachment (RRD). METHODS: Data from 120 patients with recent onset RRD without significant PVR who were suitable for scleral buckling surgery and randomized to treatment using diode laser or cryotherapy were analyzed. The primary outcome measure was reattachment at 6 months with one operation. Secondary outcome measures were pain and swelling on the first postoperative day, cystoid macular edema as assessed angiographically at 6 weeks, and visual acuity, macular epiretinal membrane, and pigment migration under the fovea at 3 months. RESULTS: There was no significant difference between the primary and secondary outcome measures between the two treatment groups, with a primary success rate of 83% in the diode group and 92% in the cryotherapy group. Pain and postoperative swelling on the first postoperative day were equivalent. Cystoid macular edema was angiographically present in 12% in the diode group and 14% in the cryotherapy group. Visual acuity of at least 20/40 was achieved in 54% of patients in both groups. The rate of PVR was 5% in the diode group and 3% in the cryotherapy group. CONCLUSION: In this study of patients with uncomplicated RD without significant preoperative PVR, the experimentally shown benefits of transscleral diode laser did not result in significant improvement in the results of reattachment surgery compared with cryotherapy.

Molecular identification of the renal H+,K+-ATPases.

The pharmacological properties of H+,K+-ATPase activity described in the kidney were not necessarily consistent with the properties of the well-characterized gastric H+,K+-ATPase. Recent molecular biology experiments suggest that renal H+,K+-ATPase activity may be the product of several closely related P-type ATPases. At least 3 different pumps containing the HKalpha1, HKalpha2a, and HKalpha2c subunits have been detected in rabbit kidney. The current view is that these HKalpha subunits arose through gene duplication early in evolution and the proteins evolved their differing activities over time. The HKbeta protein associates with HKalpha1 in gastric tissues and is the likely mate for the HKalpha1 subunit in renal tissues. Three distinct beta subunits have been implicated as possible partners for the HKalpha2 subunits, but it remains to be determined which beta subunit predominantly associates with the HKalpha2 subunits in vivo. Sequence analysis suggests the beta subunit was constrained by size and shape of the protein rather than specific amino acid content during the course of evolution. Multiple H+,K+-ATPases in the kidney may be an important adaptation providing redundancy for the essential physiological function of maintaining ionic balance.

H-K-ATPase in the RCCT-28A rabbit cortical collecting duct cell line.

In the present study, we demonstrate that the rabbit cortical collecting duct cell line RCCT-28A possesses three distinct H-K-ATPase catalytic subunits (HKalpha). Intracellular measurements of RCCT-28A cells using the pH-sensitive dye 2', 7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein (BCECF) indicated that the mechanism accounting for recovery from an acid load exhibited both K+ dependence and sensitivity to Sch-28080 characteristic of H-K-ATPases. Recovery rates were 0.022 +/- 0.005 pH units/min in the presence of K+, 0.004 +/- 0.002 in the absence of K+, and 0.002 +/- 0.002 in the presence of Sch-28080. The mRNAs encoding the HKalpha1 subunit and the H-K-ATPase beta-subunit (HKbeta) were detected by RT-PCR. In addition, two HKalpha2 species were found by RT-PCR and 5' rapid amplification of cDNA ends (5'-RACE) in the rabbit renal cortex. One was homologous to HKalpha2 cDNAs generated from other species, and the second was novel. The latter, referred to as HKalpha2c, encoded an apparent 61-residue amino-terminal extension that bore no homology to reported sequences. Antipeptide antibodies were designed on the basis of this extension, and these antibodies recognized a protein of the appropriate mass in both rabbit renal tissue samples and RCCT-28A cells. Such findings constitute very strong evidence for expression of the HKalpha2c subunit in vivo. The results suggest that the rabbit kidney and RCCT-28A cells express at least three distinct H-K-ATPases.

Brain SPECT imaging and neuropsychological testing in coronary artery bypass patients: single photon emission computed tomography.

BACKGROUND: Cognitive deficits appear frequently after cardiac operation. While the etiology remains unclear, alterations in cerebral perfusion during cardiopulmonary bypass may be causative. Single photon emission computed tomography (SPECT) scanning utilizes a radiopharmaceutical to provide images of cerebral perfusion. We proposed to study the cerebral circulation of patients during coronary artery bypass operation employing cardiopulmonary bypass. METHODS: Thirty-five neurologically normal patients underwent preoperative SPECT brain scanning and neuropsychological testing. A second SPECT brain perfusion scan was obtained by administering the radioisotope during cardiopulmonary bypass, with subsequent scanning upon completion of the procedure. Postoperative neuropsychological testing was performed prior to discharge. RESULTS: Fourteen (40%) of patients demonstrated significant neuropsychological decline. Patients who suffered cognitive impairment were no different in demographic, general health, or surgical variables. Patients who demonstrated neuropsychological decline had significantly poorer cerebral perfusion both at baseline and during operation. CONCLUSIONS: Impaired cerebral perfusion at baseline may identify patients at risk for cognitive injury after cardiac operation. Alterations in cerebral perfusion during cardiopulmonary bypass is common, and may be a factor in neuropsychological deficits seen after cardiac operation.

Use of silicone oil in the treatment of complicated retinal detachment: results from 1981 to 1994.

PURPOSE: To evaluate the advantages and disadvantages of the retention and removal of silicone oil in the treatment of complicated retinal detachments. METHODS: The records of 344 patients (348 eyes) that underwent vitrectomy and silicone oil injection for complicated retinal detachments were abstracted and analysed. The anatomical and functional results, complications and influencing factors are discussed. The outcome in eyes after removal of the silicone oil was compared with the outcome in a comparable group of eyes in which the silicone oil was retained. RESULTS: The overall retinal reattachment rate was 63% (220/348). The final vision of 5/300 or better was 52% (115/220) in those eyes with totally attached retinas. The silicone oil-related complications included keratopathy (23%) and secondary glaucoma (11%). Comparing removal of silicone oil with retention of silicone oil, we found: (i) there was no statistical difference in the redetachment rate (19 vs 17%); (ii) oil-removed eyes had a better final vision (P < 0.05); and (ii) keratopathy (13 vs 23%), secondary glaucoma (11 vs 25%) and optic nerve atrophy (4 vs 18%) were significantly lower in oil-removed eyes. CONCLUSION: Silicone oil injection is useful in the treatment of complicated retinal detachments. For reducing the incidence of complications, early removal of silicone oil is recommended in those cases in which the retina is attached, all breaks adequately closed and traction relieved.

Carvedilol prevents severe hypertensive cardiomyopathy and remodeling.

BACKGROUND: Carvedilol (Coreg/Kredex) is an unselective vasodilating beta-blocker with potent antioxidant activity used in the treatment of hypertension, angina, and congestive heart failure. In previous studies, carvedilol has been demonstrated to confer significant cardiac protection in acute ischemic paradigms and reduction of left ventricle hypertrophy in spontaneously hypertensive rats. OBJECTIVE: To examine the effects of carvedilol on discrete histopathologic changes in the heart induced by severe hypertension in stroke-prone spontaneously hypertensive rats. DESIGN: Three groups of stroke-prone spontaneously hypertensive rats were maintained on 1% NaCl drinking solution and a high-fat (24.5%) diet (salt-fat diet). Two of these groups had their salt-fat diet supplemented by 1200 or 2400 ppm carvedilol. The third group had the same diet but it was not supplemented with drug and this group served as a control. We fed a fourth group of stroke-prone spontaneously hypertensive rats a normal diet and used this group to define cardiac changes induced by salt-fat diet. METHODS: In total, 33 stroke-prone spontaneously hypertensive rats from these four groups (n = 7-9 in each group) survived for 18 weeks under these treatment regimens and were evaluated in terms of cardiovascular parameters and several quantitative and semiquantitative histopathologic indices that we developed to identify and compare cardiac muscle and vascular pathology/remodeling. RESULTS: Administration of carvedilol had no effect on systolic blood pressure (range for all salt-fat diet groups 288 +/- 8 to 294 +/- 6 mmHg compared with the value for the normal diet group of 228 +/- 12 mmHg) whereas heart rate was slightly reduced (by 10-18%; P<0.05). Administration of carvedilol produced a significant (P<0.01) dose-related decrease in total cardiac histologic damage (i.e. the sum of several histopathologic indices) induced by the salt-fat diet (i.e. it reduced damage by 54 and 82% at low and high doses, respectively). Specifically, administration of carvedilol produced dose-dependent reductions in histopathologic indices of coronary artery hypertrophy (by up to 88%), hyperplasia (by up to 89%), degeneration of myofiber (by up to 91%), myocardial inflammation (by up to 100%), cardiac fibrosis (by up to 67%), arterial microthrombosis (by up to 95%), and myocardial microinfarction (by up to 100%; all P<0.01). Salt-fat diet induced an increase in total cardiac mass and left ventricle-intraventricular septum cross-sectional area that was completely eliminated by administration of carvedilol (P<0.01). CONCLUSIONS: These data indicate that carvedilol provides remarkable cardioprotection, by suppressing severe hypertension-induced cardiac remodeling and myopathies at doses that do not reduce systemic blood pressure.

[An analysis of treatment of intravitreal lens fragments following phacoemulsification].

OBJECTIVE: To observe and evaluate the outcome of vitrectomy in the treatment of dropped lens fragments. METHOD: Retrospectively the authors reviewed and analyzed 58 cases of dropped lens fragments that were treated with vitrectomy from October 1992 to October 1995 in Royal Victoria Eye and Ear Hospital, Melbourne, Australia and followed for at least 3 months. RESULTS: At the last follow-up, the remained complications were cystoid macular edema in three cases (5.2%), retinal detachment in two cases (3.4%) and hypotony in one case (1.7%). Other complications were all resolved. The final vision was significantly better than that before vitrectomy. There were 38 eyes (65.5%) with final visual acuities of 0.5 or better, and only 6 eyes (6.9%) with < 0.05. CONCLUSION: Once the lens fragments are dropped into the vitreous during phacoemulsification, the ocular anterior segment should be properly managed, if possible intraocular lens is inserted, and then vitrectomy should be performed as soon as possible. Generally, with the above method good therapeutic effects can be obtained.

Infantile myofibromatosis with hemangiopericytoma-like features of the tongue: a case study including ultrastructure.

We report a case of an infantile myofibromatosis with hemangiopericytoma-like features arising in the tongue of a 5-month-old female infant. Many authors now classify neoplasms as infantile myofibromatosis that were previously called infantile hemangiopericytoma. The ultrastructural features of our tumor illustrate its biphasic nature and provide a possible explanation for its histogenesis. Infantile myofibromatosis, including those diagnosed as infantile hemangiopericytomas, rarely arise in any intraoral location. Despite the generally good prognosis associated with these neoplasms, complete surgical excision is recommended to avoid recurrences.

Is self-organized criticality relevant to alcoholism?

The concept of self-organized criticality suggests that large interactive (dynamic) systems move toward a critical state. Seen throughout nature these systems follow a power law where the amount of energy involved in a change is related to the number of events that have occurred such that N is proportional to one over E to the power b (N alpha 1/Eb), where N is the number of events, E is the energy of the event and b is a constant for the system. A pilot series of 316 individuals reporting alcohol problems were studies and the number of individuals (N) reporting number of detoxifications (DN) was found to be related such that N was proportional to one over DN to the power k (N alpha 1/DNk), where k varies with the parameters of the population studies (i.e., gender, time sober). It is hypothesized that the "disease of alcoholism" can be conceptualized to be related to the energy of effort required to move from one "attractor" (drinking) to another (non-drinking) as a power law. The results suggest that alcoholics are "attracted" to the critical state of intoxication independent of clinical presentation or initial conditions.

Autoimmune hypothesis of acquired subglottic stenosis: lack of support at time of surgical repair in children.

Numerous mechanisms have been suggested for the development of subglottic stenosis. This study sought serum antibody and cricoid cartilage immunohistologic evidence of an autoimmune process. The autoimmune hypothesis is that subglottic inflammation may extend into the cricoid cartilage, degrade the extracellular matrix and expose normally-sequestered type II collagen to the afferent arm of the immune system. The resultant anti-collagen antibodies are hypothesized to contribute to further injury and scarring. Specimens were obtained from 10 patients. Immunofluorescent stains for antibodies in histologic specimens, and serum antibodies to type II and type IX collagen were sought. No evidence for an autoimmune process was found in these specimens with the techniques used. The negative findings may be attributable to the autoimmune process being inactive at the mature stage of the disease in the patients studied.

Evaluation of a residential program using the Addiction Severity Index and stages of change.

Fifty six individuals admitted to Recovery Acres (a thirty five bed male residential recovery program/half way house) were evaluated using the Addiction Severity Index (ASI) and Socrates, an instrument designed to measure stage of change. Composite scores obtained from the ASI indicated that major problems were present in the areas of employment, alcohol, family/social, and emotional functioning. Stages of Change revealed 27% to be in preparation, 67% action, and 6% in maintenance. Patients left Recovery Acres either through relapse, or to follow a non-residential program. Follow-up of 26 cases revealed that residents showed statistically significant improvement in areas of alcohol, drug, family/social and emotional problems. Employment, medical, and legal problems as identified by the ASI composite score were significant indicators of negative outcome. Employment still remained a problem three months after admission for most residents. Stage of Change did not predict outcome in terms of abstinence or residential status.

Chronic carvedilol reduces mortality and renal damage in hypertensive stroke-prone rats.

The effects of carvedilol, a novel vasodilating beta-blocker and antioxidant, and propranolol on survival, neurobehavioral deficits, cardiovascular parameters, plasma renin, plasma aldosterone levels and renal pathology were determined in stroke-prone spontaneously hypertensive rats. Stroke-prone spontaneously hypertensive rats were allowed access to 1% NaCl as the drinking solution and a high fat diet supplemented with carvedilol (1200 or 2400 ppm) or propranolol (2400 ppm). The control group consisted of stroke-prone spontaneously hypertensive rats placed on the same diet with no drug supplement. Animals fed propranolol had a blood level of 864 +/- 68 ng/ml, whereas carvedilol-fed animals had blood levels of 24 +/- 4 ng/ml at 1200 ppm and 471 +/- 145 ng/ml at 2400 ppm. Carvedilol and propranolol treatment resulted in significant beta adrenoceptor blockade. Both compounds reduced heart rate, but had no significant effects on systolic arterial blood pressure. Carvedilol- and propranolol-treated animals also exhibited significant, prolonged protection from neurobehavioral deficits and mortality (P < .01). Elevated plasma renin activity and aldosterone levels seen in untreated controls were significantly decreased by propranolol (P < .05), and to a considerably greater extent by the same dose of carvedilol (P < .01). Carvedilol decreased renal histopathological damage and cardiac hypertrophy to a greater extent (P < .01) than propranolol (at equal doses). Both carvedilol (P < .01)- and propranolol (P < .01)-treated animals had considerably reduced renal damage at 18 weeks of treatment. Carvedilol reduced renal damage more than propranolol (P < .05). In addition, the lower (1200 ppm) dose of carvedilol, which decreased neurobehavioral deficits and mortality, had no significant effects on organ mass or renal function, but significantly (P < .01) reduced renal damage. These data indicate that both beta adrenoceptor blockers, especially carvedilol to a considerably greater degree, convey significant protection in a genetic model of severe hypertension that results in renal and cardiovascular organ pathology, neurobehavioral deficits and premature death.

Plasma and renal prorenin/renin, renin mRNA, and blood pressure in Dahl salt-sensitive and salt-resistant rats.

We measured plasma prorenin and renin levels, renal renin mRNA, renal anti-renin and anti-prorenin-prosequence immunoreactivity, and blood pressure in maturing Brookhaven Dahl salt-sensitive (Dahl S) and salt-resistant (Dahl R) rats during 14 days of low (0%), medium (0.4%), or high 4%) NaCl diets. Blood pressure was higher in Dahl S rats and did not increase with high NaCl. Seven-week-old Dahl R rats had twofold and sixfold higher levels of plasma prorenin and renal prosequence immunoreactivity, respectively, which by 9 weeks were the same as in Dahl S rats. The anti-renin antiserum, BR1-5, was found to detect prorenin better than renin; Dahl S rats had suppressed renal anti-renin immunoreactivity relative to Dahl-R rats. Dahl R rats were unresponsive to high NaCl, whereas in Dahl S rats, plasma renin and renal prosequence immunoreactivity fell by 90% (P < .01), renal anti-renin immunoreactivity and renal renin MRNA fell by 35% (P < .05 for both), and plasma prorenin fell by 30% (P = NS). NaCl depletion increased prorenin/renin parameters similarly in both strains. There were direct relationships among all of the prorenin/renin parameters. Between low and high salt diets in Dahl S rats, plasma renin increased 20-fold, plasma total renin (renin plus prorenin) and renal renin mRNA both increased threefold, and plasma prorenin increased twofold. The results indicate that under steady-state conditions, plasma and renal renin/prorenin parameters change concordantly and that plasma total renin (renin plus prorenin) reflects changes in renal renin mRNA. The lower blood pressure of Dahl R rats is associated with later maturation-related declines in plasma and renal prorenin. Suppression of plasma renin may delay the salt-induced blood pressure rise in Dahl S rats. Finally, the renin system and blood pressure of Dahl R rats have remarkable disregard for a high salt diet.

Morphogenesis of inclusion bodies of urothelial carcinoma: a case study.

The morphogenesis of inclusions of urothelial carcinoma (K. Donhuijsen et al.: Hum Pathol 23:860, 1992) is described in a case of a 51-year-old man with poorly differentiated urothelial carcinoma. Peritoneal fluid preparations contained numerous dyscohesive, large, anaplastic cells with abundant dense amphophilic cytoplasm often compartmentalized into multiple, variably sized, intracytoplasmic lumina, each containing "bull's eye"-like inclusions, with a periodic acid Schiff-positive refractile central core and an alcian blue/mucicarmine-positive rim. Ultrastructurally, the progression of osmiophilic substance from membrane-bound exocrine-type secretory granules, via exocytosis, to a presence in both intracytoplasmic lumina and extracellular space has been documented. Immunohistochemically, the periodic acid Schiff-positive refractile cores, as well as the minute periodic acid Schiff-positive granules in the cytoplasm, stained positively for secretory component and peanut agglutinins, whereas the alcian blue-positive mucinous material, which coated the refractile cores as well as the lining of the intracytoplasmic lumina, stained strongly for epithelial membrane antigen and leu M1. Ultrastructurally, protein A-gold probes, immunolabeled for peanut agglutinin and secretory component, were localized to the osmiophilic substance.

In situ hybridization of H-K-ATPase beta-subunit mRNA in rat and rabbit kidney.

Through a variety of techniques, several investigators have demonstrated the presence of an H-K-adenosinetriphosphatase (H-K-ATPase) enzyme in the renal collecting duct, suggesting that this enzyme serves an important physiological role in the regulation of acid-base balance and potassium excretion by the kidney. The present study was designed to localize cells expressing H-K-ATPase beta-subunit mRNA in rat and rabbit kidney by nonradioactive in situ hybridization. A 570-bp DNA fragment of rabbit renal H-K-ATPase beta-subunit was used to produce digoxigenin-labeled riboprobes by in vitro transcription. Northern blot hybridization demonstrated transcripts in rat gastric oxyntic mucosa and kidney. In situ hybridization on kidney tissue sections demonstrated H-K-ATPase beta-subunit mRNA localization in epithelial cells, including intercalated cells in the connecting segment and cortical and medullary collecting duct, principal cells in the inner stripe of the outer medullary collecting duct, and inner medullary collecting duct cells in both the rat and the rabbit. These observations provide evidence that H-K-ATPase beta-subunit mRNA is present throughout the collecting duct of the kidney. The distribution of this message is consistent with a role for H-K-ATPase in bicarbonate absorption in both the outer and inner medullary collecting duct.