Morphofunctional evidence of changes in principal and mitochondria-rich cells in the epidermis of the frog Rana kl. esculenta living in a polluted habitat

The epidermis of vertebrates is the body's principal barrier against environment and its possible contaminants. The presence of keratins, as well as specific detoxifying molecules or enzyme activities, in the various epidermis layers is believed to be involved in providing protection from harmful environmental influences. Anuran integument is poorly hornified and thus permeable to some endogenous and exogenous compounds and thus serves as a good bioindicator of overall environmental conditions. In the present investigation, we studied the epidermis of Rana kl. esculenta adult specimens collected at two different rice fields, relatively unpolluted and heavily polluted, respectively. Environmental pollution was assayed by chemical analysis performed on both sediments and animals. We evaluated the structural aspects of the epidermis at both light and electron microscopy levels and the pattern of keratinization by immunohistochemistry. Furthermore, we studied the activities of some enzymes (acid and alkaline phosphatase, nitric oxide synthase-related nicotinamide adenine dinucleotide phosphate dehydrogenase, glucose-6-phosphate dehydrogenase, catalase, nonspecific esterases, and succinic dehydrogenase) involved mainly in membrane transport, xenobiotics, and oxidative metabolism. Compared with controls, in polluted animals we found the following results: (1) an increase in pollutant levels (i.e., cadmium, mercury, and lead); (2) less keratinized superficial cells in the epidermis; and (3) changes in most enzyme activities in keratinocytes and mitochondria-rich cells (particularly glucose-6-phosphate dehydrogenase and esterases, both important to counteract oxidative and toxic stress). Taken as a whole, the present data indicate the morphofunctional plasticity of the frog epidermis in response to environmental contamination.

Alagille syndrome and optic pit

BACKGROUND

Optic disc anomalies are frequently associated with Alagille syndrome. We report here the first case of a patient with Alagille syndrome combined with optic pit and serous macular detachment.

METHODS

A male patient with Alagille syndrome was referred from the pediatric hepatology department for investigation of visual loss in the right eye. Anterior segment examination showed evidence of posterior embryotoxon, confirmed by gonioscopic evaluation. Dilated fundus examination revealed serous macular detachment and optic pit.

RESULTS

OCT 3 scans confirmed the clinical findings.

CONCLUSIONS

Optic pit is uncommon and should prompt a search for genetic disorders or development abnormalities. The association between the two syndromes in this patient might be due to failure of correct neuroectodermal development, for which a common genetic pathway is likely.

Hypertensive retinopathy revisited: some answers, more questions

Hypertension is associated with cardiovascular risk and systemic target organ damage. Retinopathy is considered one of the indicators of target organ damage. This review focuses on recent studies on hypertensive retinopathy and their implications for clinical care. Early recognition of hypertensive retinopathy signs remains an important step in the risk stratification of hypertensive patients.

Hypertensive retinopathy: there's more than meets the eye

Hypertension is associated with increased cardiovascular risk, leading to systemic end-organ damage, including retinopathy. However, the recent European Society of Hypertension-European Society of Cardiology and World Health Organization-International Society of Hypertension 2003 guidelines propose new prognostic indications for the classification of hypertensive retinopathy. In particular, grades I and II are no longer included among signs of end-organ damage, and only grades III and IV are retained as associated clinical conditions for the stratification of global cardiovascular risk. This review article will focus on the wider implications of clinical markers of microvascular damage in the retina, with specific reference to hypertension and end-organ damage. Early recognition of retinal changes remains an important step in the risk stratification of hypertensive patients.

Direct demonstration of iron in a term placenta in two cases of beta-thalassemia

The aim of this study was to quantify iron in the placentas at the end of pregnancy in two patients suffering from beta-thalassemia and compare the data to that recorded from the placentas of healthy women. Iron was quantified in placental specimens taken after the delivery. The specimens were subjected to chemical treatments in order to remove extracellular iron and leave the intracellular iron intact. After coloration, each specimen was subjected to quantitative analysis of images in order to identify and quantify iron. Our results demonstrated that in beta-thalassemia there is an accumulation of iron in the outer basal cytoplasm of the epithelial cells of placental cotyledons.

GB virus C/hepatitis G virus exposure in Italian pediatric and young adult thalassemic patients

BACKGROUND

The aim was to estimate the prevalence and the persistence of GB virus C/hepatitis G virus (GBV-C/HGV) exposure markers in a group at high risk for transfusion-transmitted agents.

PATIENTS AND METHODS

Serum samples from 37 thalassemic patients were screened for GBV-C/HGV RNA by reverse transcription PCR (RT-PCR) and for antibodies to the envelope protein E2 of GBV-C/HGV (anti-E2).

RESULTS AND DISCUSSION

GBV-C/HGV RNA and anti-E2 were detected in 13 (35%) and 12 (32%) sera, respectively. Contemporary presence of both markers was found in one patient. GBV-C/HGV exposure was found in 24 patients (64.8%). Mean levels of liver enzymes were similar in both exposed and unexposed GBV-C/HGV groups. 33 out of 35 patients showed no change in GBV-C/HGV RNA and anti-E2 status in sera taken 6 months apart. The rate of persistent infection was 92.3% and the anti-E2 seroconversion rate was 23% for sera taken at least 6 months apart. The temporal overlap between anti-E2 seroconversion and loss of detectable GBV-C/HGV RNA may last more than 6 months.

[Laparoscopic appendectomy. Retrospective analysis of our experience compared with the literature]

BACKGROUND

The benefits of laparoscopic appendectomy (LA) remain controversial. This study reports a critical examination of our experience in a peripheral hospital.

METHODS

A total of 128 appendectomies have been performed since January 1996, of which 63 (49%) were laparoscopic. The patients included 52 (82.5%) females and 11 (17.5%) males with a mean age of 20.8 years (range 11-46). Emergency surgery was required in 6 cases (9.5%) and was elective in 57 (90.5%). Appendectomy was performed during another operation in 3 cases (laparoscopic cholecystectomy).

RESULTS

Mortality was nil. Morbidity was 1.7% (1 case). The index of conversion was 0%. Only one major complication occurred. This took the form of perforation of an ileal loop following accidental lesion during adhesiolysis. The intraoperative diagnosis was not confirmed in 12 (19%) cases: 9 ovarian cysts, 1 terminal ilieitis and 2 cases of acute salpingitis. In 10 cases (15%) surgery was associated with adhesiolysis, and in 6 cases (9.3%) the appendix was retrocecal. Mean operating time was 42 min (range 18-105 min). The mean hospitalisation was 3.3 days.

CONCLUSIONS

The authors emphasise the numerous advantages of laparoscopic techniques in their experience, including excellent cosmetic results, reduced PO pain, rapid functional recovery, lower incidence of adhesion, wound infection and laparocele, and more cost-effective when mechanical staplers are not used. Owing to the ability to explore the entire abdominal cavity, the main advantage of this technique consisted in a correct differential diagnostic balance, especially in young women of child-bearing age, between appendectomy and pathologies of the uterus and adnexa.

[Laparoscopic cholecystectomy. Our experience]

BACKGROUND

The many advantages and extreme versatility made laparoscopic cholecystectomy (L.C.) the gold standard for symptomatic cholelithiasis. The aim of this research is a retrospective analysis of personal experience with laparoscopic cholecystectomy in a peripheral hospital compared with the literature on the subject.

METHODS

Since June 1982, a total of 989 L.C. have been performed. The patients were: 691 (68.6%) women and 298 (29.4%) men with a mean age of 56 years (range 17-84). The indications were: 791 symptomatic cholelithiasis, 142 chronic cholecystitis, 45 empyema-hydrops and 11 adenomyomatosis.

RESULTS

No postoperative death have been observed and the conversion rate was of 24 cases (2.3%). The main complications were 3 cases of injury of the biliary tract and 2 cases of postoperative bleeding (1 from cystic artery and 1 from the umbilical wound). Minor complications observed were 12 cases (1.2%) of infections of the umbilical wound and 3 cases of umbilical hernia (0.3%). The elevation of stasis index was observed in 3 cases which solved spontaneously. The length of stay was 2 days in 957 cases (97%), 8 days in 24 cases and 4-5 days in 8 (0.7%).

CONCLUSIONS

No major trochar's lesions occurred, contrary to the percentages quoted in the literature (0.02%-0.9%). The selective use of the open technique and of the multiuse conic section trocar in the "closed" technique is suggested. The 3 cases of bile duct lesions did not occur during the training period, contrary to what quoted in the literature. In personal opinion, a careful surgical technique with a good Calot's triangle preparation, is necessary to prevent these inconveniences. Parietal complications (umbilical wound infections and laparocele) even if lesser than in the laparotomy technique, can be reduced by using the endobag and suturing the abdominal fascia of the 10 mm trocars. Moreover, the use of a systematic subhepatic drainage during the first 24 postoperative hours is suggested, since it can be useful to reveal possible bleeding.

[The correlation between morphology, electrolytic content and risk factors in breast cysts]

Many studies on the biochemical composition of the liquid aspirated from breast cysts have identified three types of cysts: type I (apocrine) cysts, with a high concentration of K+ and low levels of Na+ and C1-; type II (transudate) cysts, with an electrolytic content similar to that of plasma and high Na+ levels and, finally, type III cysts, with intermediate characteristics. The literature data appear to indicate that the women with type I cysts are at higher risk for breast cancer. The authors report the results of a study carried out on 143 women from October, 1991, through October, 1994, in the Radiology Department of the University of Bologna, to investigate the correlations between some risk factors for breast cancer, the characteristics of cyst fluid and the morphology of the cysts after pneumocystography. Of 186 cysts, 104 (55.9%) were type I, 49 (26.4%) were type II, and 33 (17.7%) were type III. Among the risk factors we considered, only the premenopausal state (41 to 45 years of age) exhibited a statistically significant correlation with the presence of type I cysts. The morphological study of the cysts after pneumocystography showed a surprisingly high correlation between the honeycomb pattern and type I cysts. The constant correlation between cyst morphology and electrolytic content may allow the easy identification of the subgroups of patients eligible for a closer follow-up.

Anion-induced dynamic behavior of apical water channels in vasopressin-sensitive epithelia exposed to mercury

We showed recently that, in toad skins preexposed to Hg, water permeability is high in SO4-Ringer and low in Cl-Ringer. This anion effect was further investigated in Hg-treated skins and bladders of toads (Bufo marinus) in a variety of experimental conditions, including glutaraldehyde fixation and stimulation by vasopressin (VP) or isoproterenol (IP). In fixed bladders either unstimulated or stimulated with VP, net water flow (Jw) in SO4-Ringer [Jw (SO4)] was always significantly higher than Jw in Cl [Jw (Cl)]; the same applies to fixed toad skins, either unstimulated or stimulated with IP. In unfixed isolated toad epidermis challenged with IP before Hg exposure, Jw(SO4)/Jw(Cl) >> 1 approaching the ratio Jw (maximally stimulated)/Jw (basal). Therefore, anion-induced Jw changes were present whether Hg acted on epithelial water channels exocytosed by Hg itself or by hydrosomotic agents and suggest a switching between open and closed configurations of the channel protein. This anion effect was not abolished by glutaraldehyde and might be correlated with changes in intracellular chloride.

Mercury blockage of apical water channels in toad skin (Bufo marinus)

1. Net water flow (Jw) was continuously monitored across the abdominal skin of the toad Bufo marinus by means of a volumetric, automatic technique. Jw was either averaged over periods of 2 min or taken cumulatively (10 or 30 min periods). 2. The state of high water permeability induced by vasopressin or isoprenaline was reversed (88-89% inhibition of delta Jw after 1 h) by the addition of 10(-3) M HgCl2 (or CH3ClHg) to the external bathing medium. Similarly, pre-exposure of the skins to Hg2+, totally blocked the induction of the hydrosmotic response to the same agents. By itself, Hg2+ exerted only a minor (26%) stimulation of basal Jw. 3. There was a sigmoidal dose-response relationship between the reduction of the hydrosmotic effect of vasopressin (VP) and the concentration of Hg2+ in the external medium, with a half-maximal effect at 1.2 x 10(-4) M HgCl2. 4. Total replacement of Na+ by K+, Rb+ or Cs+ in the Ringer solution, caused a VP-like, hydrosmotic effect that was reversed, or prevented, by exposure to Hg2+ in a manner indistinguishable from that previously seen with vasopressin or isoprenaline. 5. The data point to the presence of a Hg(2+)-sensitive apical water pathway in stimulated epithelia, very probably constituted by water channels similar to those reported in red blood cells, amphibian bladder and mammalian kidney tubules.

Effects of anions and/or cell volume on the permeance of an apical water pathway induced by Hg in toad skin epithelium

Hg compounds block membrane transport units behaving as water channels. Here we show that Hg induces an apical water pathway in toad skins pretreated with 10(-3) M CH3ClHg or HgCl2, added to the outer bathing medium. Washing with SO4-Ringer caused a several-fold increase in net water flow (Jw) and osmotic permeability coefficient (Pf) that was reversed by re-exposure to Cl- or NO3-Ringer and mimicked by gluconate-Ringer. These Pf changes could be elicited repeatedly and were present if, and only if, anion replacements took place in the inner bathing solution. Such inner polarity was related to the anion permeability of the epidermal basolateral membrane: impermeant anions (SO4, gluconate) increased Pf; permeant anions (Cl, NO3) did not change basal Pf but reversed the high Pf induced by impermeant anions. Hg induced the appearance of aggregates that persisted despite repeated washings of the skins during 4-5 h, and whether Pf was high (SO4-Ringer) or low (Cl-Ringer) before skin fixation. The Hg-induced apical water pathway in toad skin appears to be a unique model for studying the interplay between cell volume, cell ionic composition and water permeability.

The growth response of the green alga Chlorella vulgaris to combined divalent cation exposure

Using the growth response of the green alga Chlorella vulgaris as a model system, the effects of combinations of the environmentally active cations Cd, Co, and Cu were evaluated. The 96-h static EC50 for these cations to C. vulgaris were, respectively, 0.89 microM, 9.0 microM, and 2.8 microM, yielding a toxicity series such that Cd > Cu > Co. The cation combinations of Cd + Cu, and Cu + Co acted synergistically, while Cd + Co, and the tri-metallic combination Cd + Cu + Co resulted in antagonistic interactions. Examination of these toxic combinations at 24, 48, 72, and 96 h indicate that the cellular response is not a uniform one. Failure of energy dispersive X-ray spectrophotometric analysis to demonstrate any intracellular incorporation of these cations (except for a weak cytoplasmic Cu peak at the 8.0 KEV position) suggests that the toxic actions of these cations at EC50 concentrations are exerted at the level of the plasma membrane.

The effects of pH on the growth of Chlorella vulgaris and its interactions with cadmium toxicity

The effects of pH alone, and in combination with exposure to 0.89 microM cadmium, on the growth response of the green alga Chlorella vulgaris were evaluated. Acidic (3.0-6.2) and alkaline (8.3-9.0) pH values retarded the growth of this alga. Optimal growth occurred when the pH of the medium was adjusted to values of 7.5 and 8.0. When the cells were exposed to pH adjusted medium plus the presence of 0.89 microM Cd, a value known to reduce population growth by 50% at the control pH of 6.9, the affects were additive at the acidic (3.0-5.0) pH ranges. At alkaline pH values of 8.3-9.0 all toxicity responses could be explained by pH adjustment alone, indicating that additional cadmium toxicity was absent. At pH values of 7.5 and 8.0, cadmium toxicity was mitigated against, and resultant growth at pH 8.0 was at the same enhanced rate as this pH without cadmium.

Amiloride inhibits the vasopressin-induced increase in epithelial water permeability

The vasopressin (VP)-induced increase in water permeability in high-resistance, amphibian epithelia is not altered by the abolition of net Na+ flux caused by amiloride added to the apical bathing medium. In this work we looked at the effects on water transport of amiloride added to the serosal medium at a concentration (10(-3) M) known to inhibit Na+/H+ exchange. In urinary bladders of Bufo marinus, amiloride partially blocked the hydrosmotic response to VP. A similar inhibition was found with cyclic adenosine 5'-monophosphate (cAMP) or serosal hypertonicity. We hypothesized that this effect of amiloride could be due to an inhibition of Na+/H+ and/or Na+/Ca2+ antiporters present in the epithelial basolateral membrane and looked at the effects of the diuretic in Na(+)-free media. A similar degree of inhibition of water flow was still found, thus showing that amiloride acts on a cell target other than the antiporters. In toad skin, amiloride did not inhibit the hydrosmotic response to VP and to isoproterenol; however the response to high K+ was significantly reduced. Among the amiloride cell targets described so far, adenylate cyclase and protein kinase A appear to be the best candidates to explain the inhibition of the hydrosmotic response reported here. Direct measurements of intracellular cAMP are needed however to substantiate this hypothesis.

Forskolin mimics the hydrosmotic action of vasopressin in the urinary bladder of toads Bufo marinus

Net water flow JW was measured across the urinary bladder of toads Bufo marinus and averaged over periods of 1 min by means of a volumetric, automatic technique. The diterpene forskolin, an activator of adenylate cyclase bypassing the hormonal receptor subunit, induced a rapid, reversible, dose-dependent increase in osmotic water permeability, Pf, very similar to that induced by vasopressin. At 1.1 microM, forskolin induced a half-maximal response. At 5 microM forskolin caused a near maximal response and Pf increased from 1.66 +/- 0.15 to 66.6 +/- 2.99 microns s-1. In bladders pre-exposed to 5 microM-forskolin, further significant increases in Pf were obtained by their subsequent exposure to vasopressin, cyclic AMP, theophylline or serosal hypertonicity. The similarity of the forskolin and vasopressin actions was further demonstrated by the finding that substances causing enhancement (quercetin) or inhibition (trifluoperazine, vanadate, silver, cobalt, manganese and Ca2+-free Ringer solution) of the vasopressin response, induced parallel changes in the forskolin response. Three agents, however, induced dissimilar effects on vasopressin and forskolin: high K+ potentiated vasopressin but inhibited forskolin; methohexital and diamide inhibited vasopressin but had no effect on forskolin. The forskolin-induced hydrosmotic response can be viewed as a new criterion for ascertaining the messenger role of cycle AMP in the the hydrosmotic effect of vasopressin.