Sulfated glycolipids in ciliary body epithelium

The sulfated material which locates in the basal membrane of ciliary body epithelium when immature rat eyes are incubated with Na235SO4 was studied. On the basis of its chromatographic behavior compared with standard preparations, we conclude that the material consists of sulfatides.     

Electrogenic cation transport across leech caecal epithelium

This paper is based on the analyses of data collected in the Tanzania Demographic and Health Survey (TDHS). The TDHS national sample was obtained by using 1988 population census list of enumeration areas. Information about sexual behaviour and condom use was obtained from sexually active women (N = 4620) and men (N = 1440) reporting sexual activity during the period of four weeks preceding the survey. Univariate and multivariate (using logistic regression model) analyses were done to identify predictors of condom use and highrisk sexual behaviour. About 6% of women and 31% of men reported to have more than one sexual partner during the study period. Compared to respondents married once and in monogamous union, the tendency to have multiple partners was increased among never married women [OR 10.9, 95% CI (7.1-16.9)] and men [2.6 (1 7-3.9)], formerly married women [11.5 (7.3-17.9)], and among men in monogamous marriage reporting more than one marriage [12.4 (8.3-18.4)]. Occupation, residence, ever use of contraceptives, and AIDS knowledge were not associated with history of multiple sexual partners. Only 134 (9.3%) men and 173 (3.7%) women reported to have used condoms during the study period. After adjusting for other predictors of condom use, respondents reporting multiple sexual partners were more likely to have used condom among both women [3.4 (2.2-5.4)] and men [3.3 (2.3-6.0)]. Condom use was common in urban areas than rural areas and among unmarried respondents. These results show that high-risk sexual behaviour is common among men. Condom use was very low indicating that efforts to promote condom use has been less successful in Tanzania. More efforts are needed to promote safer sexual practices and condom use in Tanzania.     

Active transport of nitrofurantoin across the mammary epithelium in vivo

Nitrofurantoin is a commonly used urinary tract antibiotic that has been found at high concentrations in human milk. In vivo studies in rats were carried out to determine the mechanism by which this drug crosses the mammary epithelium. Lactating rats were gavage-fed with nitrofurantoin, and their milk and plasma levels of the antibiotic were measured at intervals up to 8 hr. The average milk-to-plasma (M/P) ratio, calculated from the areas under the milk and plasma curves, respectively, was 23 compared with a ratio predicted to be about 0.3 on the basis of lipid partitioning and protein binding determinations. M/P ratios for two nitrofurantoin congeners were also calculated. The neutral compound furazolidone had a M/P ratio of about 1, as predicted, whereas the basic compound furaltadone had a M/P ratio of 3.49 compared with a predicted ratio of 1.4. These data suggest that nitrofurantoin and, to a lesser extent, furaltadone are actively transported across the mammary epithelium into milk.     

Salt and water transport across the alveolar epithelium in the developing lung: correlations between function and recent molecular biology advances (Review)

Significant progress have been made in understanding the mechanisms of alveolar fluid clearance at the time of birth and the transition from placental oxygenation to air breathing. During fetal life, the mammalian lung is a fluid filled secretory organ that fills no respiratory function. Its potential air spaces are filled with fluid that is actively secreted in response to an osmotic force generated by Cl(-)-secretion and the fluid-filled lung is necessary for a proper development of the air-breathing lung. As term approaches, net Cl(-)-secretion decreases, which is accompanied by a decreased secretion rate of the fluid into the air spaces. Concomitantly with the decreased Cl(-)-secretion, the alveolar epithelium begins to absorb Na+ to prepare for fluid absorption and the air breathing life. The causes for the decreased Cl(-)-secretion and the beginning of the Na+ absorption are not clear. Alterations in the hormonal milieu of the lung as well as changes in plasma stress hormone levels have been suggested to play roles. The switch from a placental oxygenation to pulmonary oxygenation requires that the fluid in the air spaces be rapidly removed from the lung lumen. Recent studies have demonstrated that removal of the alveolar fluid at birth is regulated via endogenous plasma epinephrine in the newborn. Molecular, cellular, and whole animal in vivo studies have demonstrated that fluid absorption at birth is related to expression and function of the epithelial sodium channel (ENaC). Several different in vivo and in vitro preparations have been used to investigate the mechanisms of alveolar fluid transport, primarily in adult lungs and have demonstrated that alveolar fluid absorption is driven by active Na+ transport. Both catecholamine-dependent and -independent regulatory mechanisms have been identified, probably acting on ENaC and other apical sodium channels and/or the basolaterally located Na+, K(+)-ATPase. Future studies are needed to integrate new insights to the molecular mechanisms behind fluid clearance with their function in both normal and pathological lungs.     

Early postirradiation changes in Na+ and fluid transport across alveolar epithelium in rats]

We improved the enzyme-linked lectin-binding assay (ELLA) to determine the differences in the carbohydrate chains of corpus, antral, duodenal ant colonic rat mucins. First we have improved the optimal conditions of this assay for mucins; ELLA makes possible the detection of 1.5 ng of hexose in rat gastrointestinal mucins (5-7 ng of mucins). Salt concentrations of several dozens mM are required for mucin coating on the plate. Non-ionic detergents diminish the adsorption of mucins onto the plate. Secondly we tested a set of 8 lectins to compare their binding to the gastrointestinal mucin samples. It is possible to detect crude mucins as well as purified mucins using ELLA. Gastric mucins have less Tn-antigen than duodenal and colonic mucins. Corpus and duodenal mucins have more of the H-type 2 chain than antral and colonic mucins.     

Permeation and pathways of human calcitonin (hCT) across excised bovine nasal mucosa

In vitro permeation of human calcitonin (hCT), salmon calcitonin (sCT), and the somatostatin analog octreotide (SMS) through excised bovine nasal mucosa was studied applying donor/receiver experiments and confocal laser scanning microscopy. Permeabilities of gonadorelin, buserelin, Hoe013, and of thymopoietin fragments TP5 and TP4 were also included. Apparent permeability coefficients (Peff) ranged between 4 x 10(-5) (SMS) and 1.7 x 10(-5) cm s(-1) (TP4). Such Peff are typical for leaky-type airway epithelia. The order of permeabilities was: SMS > hCT, sCT > buserelin, Hoe013 > TP5 > TP4, LHRH. The relatively high permeability of hCT and sCT contrasted to their high molecular weight. At 37 degrees C, the permeability of hCT from mucosal to serosal (m-to-s) was found two-fold higher (p < 0.05) than from serosal to mucosal (s-to-m). Controls using 3H-mannitol showed equal permeabilities in both directions. At 4 degrees C, permeation of hCT was reduced but equal in both directions (m-to-s and s-to-m). As evaluated by confocal laser scanning microscopy, uptake studies with FITC-18-hCT revealed intracellular fluorescence in the epithelial cells, at 10 min/10 microM exposure in the form of fluorescent vesicles. By combination of these findings, an endocytotic pathway is suggested to contribute to the transport of hCT through nasal epithelium.     

Decreased sodium ion absorption across nasal epithelium of very premature infants with respiratory distress syndrome

OBJECTIVE AND STUDY DESIGN: Successful adaptation to air breathing at birth depends on rapid absorption of fetal lung liquid that is mediated by activation of amiloride-sensitive sodium ion channels. To test the relationship between respiratory epithelial Na+ transport and development of respiratory distress syndrome (RDS), we measured nasal transepithelial potential difference (PD) in 31 very premature (< or = 30 weeks of gestation) newborn infants. Infants were retrospectively assigned to RDS (22 infants) and non-RDS (9 infants) groups on the basis of clinical and chest x-ray criteria. RESULTS: Maximal nasal epithelial PD increased with birth weight (-1.2 mV/100 gm) and was lower in infants with RDS (-16.5 +/- 0.6 mV) than in those without RDS (-22.0 +/- 1.3 mV). Infants without RDS had PD values similar to normal fullterm infants. Amiloride inhibition of PD, an index of Na+ absorption, was significantly lower, within the first 24 hours of life, in infants in whom RDS developed (3.8 +/- 0.2 mV; 29.5% +/- 0.8% inhibition) than in those without RDS (6.1 +/- 0.6 mV; 38.6% +/- 0.5% inhibition). Maximal and amiloride-sensitive PD returned to normal during the recovery phase of RDS. CONCLUSIONS: We conclude that Na+ absorption across nasal epithelium increases with increasing birth weight and that impairment of Na+ absorption across the respiratory epithelia of very premature infants may contribute to the pathogenesis of RDS.     

The effect of mitomycin C on activities of carbonic anhydrase and ATPase of the ciliary body epithelium in rabbit]

At the opposite of HLA-DR, HLA-DQ was not well documented in homogeneous negro?d populations. So, 93 IDDM and 115 control patients, all black senegalese people, were studied. The results showed three HLA-DQ IDDM-related susceptibility genotypes and also a high risk conferred by HLA-DR4/DR9 usually described in Mongolo?d people. Furthermore, DR:DQ associations allowed the identification of three IDDM predisposition genotypes, each of them with a characteristic mean age for disease diagnosis.     

Orbital extension of Choroidal and ciliary body melanomas

In a review of 432 choroidal and ciliary body melanomas, histopathologic evidence of orbital extension was found in 45 cases (10.4 percent). The occurrence of orbital extension was influenced mainly by the cell type (P less than .05) and by the size of the choroidal mass (P less than .001). Local orbital recurrence occurred in 23 percent of cases with evidence of extrascleral extension. Survival rates were independent of cell type, pigmentation, and size and shape of the extension. Patients treated by exenteration had significantly better prognosis than nontreated patients or patients treated by chemotherapy, radiotherapy, or local excision (P equals .0002). Early exentration is the best treatment for choroidal melanomas with orbital extension.     

Evidence for a sodium ion exchange carrier linked with glucose transport across the brush border of a flatworm (Hymenolepis diminuta, Cestoda)

The manner in which the flatworm, Hymenolepis diminuta (Cestoda), regulates the transport of glucose and Na+ across the brush border was examined. While the presence of an unstirred region in the brush border may favor the reabsorption of leaked glucose, some leaked glucose was lost to the ambient medium. This loss was markedly enhanced by preloading the worms with glucose and by removing Na+ from the incubation medium. Since glucose and Na+ influxes are coupled, glucose leakage stimulated the influx of 22Na+. However, this 22Na+ influx was balanced by a simultaneous increased 22Na+ efflux. The presence of phlorizin inhibited both unidirectional fluxes of 22Na+ indicating that efflux of 22Na+ occurred by countertransport; countertransport of [14C] glucose appeared to be negligible. A model has been proposed in which the transport of glucose and compensating transfers of Na+ across the membrane occur via the same carrier.     

Sodium chloride transport across the chicken coprodeum. Basic characteristics and dependence on sodium chloride intake

1. The transport characteristics of the chicken coprodeum have been examined in vitro using the isolated mucosa. The short-circuit current (I(sc)), the transepithelial electrical potential difference (p.d.), the unidirectional transmural fluxes (J(ms), J(sm)) of sodium and chloride measured in the short-circuited state, and the unidirectional influx of sodium and chloride across the brush border membrane measured under open-circuit conditions have been studied. The effect of the sodium chloride contents of the diet on these parameters have been investigated.2. The isolated mucosa depends functionally on the presence of glucose in the incubation media. This dependence reflects the need of glucose as a fuel. There is no indication of coupling between transport of sugars and sodium across the brush border membrane. For preparations from chickens on a low sodium diet a very high and stable I(sc) can quantitatively be accounted for by the net transport of sodium. Influx of sodium across the brush border membrane is not significantly different from the net flux of sodium. By feeding the chickens a high sodium diet the I(sc) is reduced by more than 95%, the net transport of sodium is abolished, and the transepithelial electrical conductance is reduced by more than 50%.3. Both unidirectional transepithelial fluxes of chloride, and the serosa to mucosa flux of sodium appear to proceed through a paracellular shunt.4. Under the conditions of the low sodium diet the paracellular pathway appears to be anion selective. Whereas, under the conditions of the high sodium regimen the paracellular route appears to be cation selective. After adaptation to a high sodium diet the influx of sodium across the brush border membrane is only moderately reduced. Consequently the decisive event in the adaptation must be localized elsewhere.     

Endoresection of the iris and ciliary body in epithelial downgrowth

We present a case of epithelial downgrowth with intractable glaucoma after multiple intraocular surgeries. The eye was successfully managed with a pars plana approach. The iris and epithelial tissue over the ciliary body were removed with intraocular scissors and a vitrector combined with unipolar diathermy and endophotocoagulation. The use of moderate hypotensive anesthesia may have helped prevent intraoperative hemorrhage. During more than 3 years of follow-up, intraocular pressure ranged from 13 to 19 mm Hg, visual acuity was 20/80 with aphakic correction with a rigid gas-permeable lens, and there was no recurrence of epithelial downgrowth.     

Inhibition of sodium transport by prostaglandin E2 across the isolated, perfused rabbit collecting tubule

This study was designed to examine whether prostaglandin E2 can directly affect sodium transport across isolated perfused rabbit renal collecting tubules. Changes in transepithelial potential and isotopic sodium fluxes in response to peritubular prostaglandin E2 were measured. In addition, changes in transepithelial potential of the outer medullary collecting tubule in response to prostaglandin E2 were also measured. With few exceptions, all rabbits received 5 mg/day desoxycorticosterone acetate for 4-11 days before experimentation. The results of the experiments show that: (a) prostaglandin E2 inhibits the negative transepithelial potential in the cortical collecting tubule as well as the outer medullary collecting tubule; (b) prostaglandin E2 inhibits net sodium transport out of the lumen by inhibiting efflux while backflux is unaffected; (c) prostaglandin E2 produces this inhibition within 15 min, and the effects are dose dependent and reversible. These results suggest that prostaglandin E2 may modulate sodium transport in vivo and may contribute to the final regulation of sodium excretion.     

The transport of calcium and sodium ions across bilayers induced by neutral synthetic ligands used in specific electrodes

Neutral synthetic ligands of calcium and sodium which enter into the liquid membrane composition of the selective electrodes of these ions have been incorporated within the bilayer. The membrane conductance measured shows that each of these two ligands behave as ion carriers for calcium or sodium ions. The selectivities with respect to the other alcaline or alcaline earth ions are similar to those observed by potentiometric measurements with thick liquid membrane selective electrodes.     

Effect of some operating variables on cobalt(II) transport across a bulk liquid membrane

An experimental study is presented on facilitated transport of cobalt(II) cations through a bulk liquid membrane containing di(2-ethylhexyl)phosphoric acid (D2EHPA). The effects on the kinetics of cobalt(II) transport of stirring rate of the receiving phase and its acidity, mobile carrier (D2EHPA) concentration, emulsifier (Span 80) concentration, initial cobalt concentration, interfacial area, and membrane thickness have been investigated. It has been found that cobalt transport increased with both stirring of the receiving phase and its acidity, while the presence of emulsifier reduced this transport, particularly at the membrane/receiving phase interface. Moreover, the mean cobalt transport rate was practically independent of membrane/feed solution interfacial area (under experimental conditions), while this rate substantially increased with the initial cobalt concentration in aqueous feed solution.     

Primary ciliary dyskinesia (the immotile cilia syndrome)

OBJECTIVE: The purpose of this review is to familiarize the reader with the genetic aspects, clinical manifestations, diagnostic techniques and management of the primary ciliary dyskinesia syndrome. Further, this article illustrates some unusual features of this syndrome and discusses some speculative hypotheses concerning its pathogenesis and clinical presentation. DATA SOURCES: The bibliography includes references in English as well as some references of historical interest in German. Both human and veterinary literature are quoted. Sources included computerized bibliographic searches of recent literature and reviews of literature. STUDY SELECTION: Selection of papers was made based on their historic importance in the definition and characterization of the disease, and on reviews of large bodies of novel or interesting information. Some review papers were not included to avoid repetition. RESULTS: Although the incidence of primary ciliary dyskinesia is low, the inclusion of this condition in the differential diagnosis of chronic and recurrent sinobronchial disease in children and older individuals is very common. Primary ciliary dyskinesia should be suspected in individuals who present chronic respiratory symptoms already in the neonatal period, develop profuse, chronic mucopurulent rhinorrhea, and chronic otitis media and sinusitis. Chronic cough, obstructive lung disease, and bronchorrhea associated with the aforementioned manifestations should also make clinicians suspect this syndrome. Male sterility is almost universally present and situs inversus is present in 50% of affected persons. The diagnosis of primary ciliary dyskinesia is clinical and is confirmed by studies of ciliary motility and ultrastructure of the respiratory mucosa. Management is directed to microbial suppression by frequent antibiotic administration, and to clearing of retained secretions. CONCLUSIONS: The diagnosis of primary ciliary dyskinesia requires familiarity with the clinical picture and the specific techniques of identification. Although the basic mechanism of disease is known, the molecular genetics of primary ciliary dyskinesia and the causes for the phenotypic variability remain to be explained. Future research should be directed to the identification of the gene(s) responsible for the manifestations of the disease and to effective methods of activation, in vivo, of dysfunctional cilia.     

Immunohistochemistry of secretory particles (''vesiculosomes'') from the epithelium of bovine seminal vesicles and ampulla of the vas deferens

Several syndromes involving antiphospholipid antibodies have been described in the literature. Although the varied clinical manifestations have been well delineated, the vascular pathophysiology in patients with these antibodies remains unclear. Vascular damage is often described as a vasculopathy; however, several case reports have described an associated vasculitis. We report two patients with manifestations of antiphospholipid antibody syndrome (APLS) and concurrent vasculitis. The first patient, a 42-year-old man, presented with abdominal pain and fevers. The second patient, a 39-year-old man, presented with fever and testicular pain. Both were ultimately felt to have polyarteritis nodosa associated with APLS. Their complicated hospital courses and difficulties we encountered in diagnosing and treating them are discussed. The literature describing other cases of vasculitis associated with antiphospholipid antibody syndrome is reviewed. Whether the presence of antiphospholipid antibodies favors the development of vasculitis or vice versa is not clear. Further studies are needed to address this question and to determine optimal therapeutic regimens in these critically ill patients.