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A Guinea

Publications and source records attributed to A Guinea.

At least 19 recordsLinked to original sources
PubMed2002

Ciliate communities of rotating biological contactor biofilms: a multivariate approach.

Physical-chemical monitoring and characterization of ciliate communities from a full-scale rotating biological system (RBC) have been carried out for a year. RBC system operated efficiently in removing the organic matter, as the decrease of the BOD5 loading along the successive RBC units revealed. 55 species of ciliated protozoa were identified in the RBC biofilms. Differences in abundance, occurrence and type of species were found along the different units of the RBC system; the last RBC held a more stable and diverse ciliate community. The complexity of interspecific relationships among the ciliates has been outlined using multivariate methods (Cluster and Correspondence analysis). Correlation between ciliate species and physical-chemical conditions were obtained by regression analysis. Results show that 12 species of ciliates were related to an optimal efficiency in organic matter removal, Litonotus crystallinus being the most sensitive species. The presence and abundance of Litonotus crystallinus and Acineria uncinata was associated with a decrease in the organic factor. Metopus es was the only species related to a decrease in process efficiency due to its association with an increase in organic factor. The results provide statistical evidence of the use of certain ciliate species as reliable bioindicators in full-scale RBC wastewater treatment plants.

Animals↗
PubMed2002

An integrated approach to analyse biofilms of a full scale wastewater treatment plant.

A rotating biological contactor (RBC) system operating in a full-scale wastewater treatment plant has been described by several approaches accounting for performance, composition and structure of biofilms in three stages through biological wastewater treatment (RBC1, RBC 2, RBC 3). RBC biofilms were effective in removing the BOD loading from 13 g BOD5 d(-1) m(-2) in RBC 1 to 6 g BOD5 d(-1) m(-2) in RBC 3. Analysis of biofilm composition showed: i) the volatile solids were similar in the three RBCs (0.6 g m(-2) VS per g m(-2) of TS); ii) the protozoan and metazoan biocenosis was mainly made up of ciliated protozoa, which were most abundant in RBC 2 (1.84 x 10(6) ciliates g(-1) VS). Relationship between ciliate species and physical-chemical profile of the system by cluster analysis indicated that the species Acineria uncinata, Amphileptus punctatus, Cinetochilum margaritaceum and Holosticha mancoidea were associated with the best RBC performance; iii) the exopolymeric matrix of the three RBC biofilms was mainly constituted by proteins, although humic substances, polysaccharides, uronic acids and DNA were also found. Analysis of biofilm structure by confocal microscopy indicated changes in biofilm organisation with depth. Results have been brought together and a graphic representation of the composition and architecture of RBC biofilms is presented.

Animals↗
PubMed2001

Dynamics of protozoan and metazoan communities in a full scale wastewater treatment plant by rotating biological contactors.

Performance of a full-scale wastewater treatment plant by rotating biological contactors (RBC) system was monitored during a year by physico-chemical and microbial characterisation. Six points along wastewater treatment were selected in the plant: three points along the water line (influent, sedimentation tank and effluent) and three points along RBC system (RBC1, RBC2 and RBC3). Although a large seasonal change in the values of physico-chemical parameters was observed, operation of the plant was optimal during all year (90% of removal in BOD5 and SS influent content). Microbial characterisation was approached by determining the structure and dynamics of protozoan and metazoan communities. Protozoa were the most abundant in all stages in the plant, heterotrophic flagellates being the most representative group in the water line and ciliates in the RBC system. The same seasonal preference was only observed for heterotrophic flagellates in the water line and green flagellates in the RBC system, both groups having highest abundances in summer and spring, respectively. Identification of ciliated protozoa populations rendered 58 species of ciliates in the plant. Most of these species are typical of aerobic wastewater treatment systems except three of them, which are cited for the first time in this type of ecosystems: Chaenea stricta, Holosticha mancoidea and Oxytricha lanceolata. Along the water line 34 species were identified, and half of them only appeared occasionally (once in all the study), while along the RBC system biofilms 55 species were observed, and the majority appeared permanently in this system. Our results indicate that the type of habitat, rather than the physico-chemical water parameters, was the primary factor in determining the different distribution of protozoan and metazoan communities in the plant. In RBC biofilms, the structure of ciliate protozoa community was found to be quite sensitive to changes in physico-chemical parameters, mainly to organic loading (BOD5) variations.

Amoeba↗
PubMed2001

Characterization of extracellular polymeric substances in rotating biological contractors and activated sludge flocs.

Extracellular polymeric substances (EPS) from biofilms of a rotating biological contactor (RBC) system and from activated sludge flocs were extracted using ultrasound and a cation exchange resin. In both wastewater treatment systems, the EPS matrix was mainly constituted of proteins, humic-like substances and polysaccharides, although other components--DNA and uronic-like substances--were also present. The composition of the biofilm EPS was different in the succesive RBC wastewater treatment stages: protein had its highest concentration in the first RBC unit, while humic substances and polysaccharides in the third RBC. Significant differences between biofilm and sludge floc EPS were also reported. The amount of proteins was 3.5 times higher for RBC biofilms than for sludge flocs, and quantities of humic substances and polysaccharides extracted from biofilms were twice as high than in sludges. Moreover, biofilm exopolymers were two times more hydrophobic than those of sludge flocs. Implications of wastewater chemistry and microbial growth strategies into EPS composition and properties are suggested.

Biofilms↗
PubMed2000

Blood chemistry profile of a South Pacific Island population.

AIMS: To determine basic blood chemistry parameters in the population of the island of Mauke in the South Pacific. METHODS: As a part of a health survey carried out in 1992, 24 laboratory parameters were measured in serum samples of 502 subjects representing 80.8% of the total population. RESULTS: Blood glucose, uric acid and globulin values were above the respective reference intervals in 9%, 5% and 4% of the subjects. Blood urea nitrogen and serum creatinine values were elevated in 1.8% and 1.2% of the subjects. Hypoalbuminaemia was found in 1.2% to 4% of the subjects, more frequently in the older age groups. Gamma glutamyltransferase levels were elevated in 6.2% of the subjects. Iron values were below the reference interval in 8.0% of the subjects. Serum cholesterol levels were elevated in 4.4% of the subjects. CONCLUSIONS: The blood chemistry data reflect the disease profile of this Pacific Island population including the presence of diabetes and iron deficiency as well as renal, hepatic and infectious diseases. The data can be used in comparative inter-island studies as well as in those between Pacific Island and other populations.

Adolescent↗
PubMed1999

Multinodular goitre presenting as a clinical single nodule: how effective is hemithyroidectomy?

BACKGROUND: Patients who present with a single thyroid nodule that requires surgery will generally undergo hemithyroidectomy. If, however, the subsequent histological examination shows unsuspected multinodular change, there is a risk of recurrence in the remain ing lobe. The aim of this study was to determine the clinical outcome in patients who have had a hemithyroidectomy for a single thyroid nodule that was shown on subsequent histopathological examination to be part of a multinodular goitre. METHODS: A survey was undertaken of patients who were identified from a thyroid surgery database with the following criteria: (i) hemithyroidectomy for clinical single nodule; and (ii) multinodular change on histopathology. Main outcome measures were clinical recurrence rate, the frequency of further thyroid surgery, and the efficacy of thyroxine treatment on recurrence. RESULTS: In the 229 patients studied, the clinical recurrence rate was 12%. Fourteen of the 28 patients with recurrence required further surgery. Thyroxine therapy did not influence the recurrence rate. CONCLUSION: When surgery for a clinically benign single thyroid nodule is indicated, hemithyroidectomy is an adequate surgical procedure in cases where the single nodule is subsequently found to be part of a multinodular goitre. Such patients can be reassured that the chance of clinical recurrence is low. Thyroxine replacement therapy appears not to prevent recurrence.

Adolescent↗
PubMed1999

Age is no contraindication to thyroid surgery.

BACKGROUND: There is increased risk of surgical treatment in elderly patients, but little has been written on the safety and efficacy of thyroid surgery in this group. OBJECTIVE: To determine if there is an increased risk of morbidity and mortality of thyroid surgery in patients over 75 years old. PATIENTS AND METHODS: During the period 1986-96, 1631 patients aged 50 and over underwent 1673 procedures by two surgeons in our unit. We retrospectively compared indications for surgery, procedures, pathology complications and mortality in three groups: 50-60-year-olds (725 patients), 61-74-year-olds (685 patients) and those aged 75 years and over (221 patients) RESULTS: The main indication for surgery in all three groups was compression or risk of malignancy. Total thyroidectomy was the main procedure performed. Although benign multinodular goitre was the commonest diagnosis, the over-75-year-olds had fewer benign multinodular goitres than the 61-74 group and more malignancy than the other two groups. There was no significant difference in mortality between the three groups. CONCLUSIONS: Surgery in patients over 75 is as safe as in younger patients with no increase in morbidity and mortality. Benign multinodular goitre is the most common indication for surgery.

Age Factors↗
PubMed1998

The plasma membrane of Leishmania donovani promastigotes is the main target for CA(1-8)M(1-18), a synthetic cecropin A-melittin hybrid peptide.

Reports on the lethal activity of animal antibiotic peptides have largely focused on bacterial rather than eukaryotic targets. In these, involvement of internal organelles as well as mechanisms different from those of prokaryotic cells have been described. CA(1-8)M(1-18) is a synthetic cecropin A-melittin hybrid peptide with leishmanicidal activity. Using Leishmania donovani promastigotes as a model system we have studied the mechanism of action of CA(1-8)M(1-18), its two parental peptides and two analogues. At micromolar concentration CA(1-8)M(1-18) induces a fast permeability to H+/OH-, collapse of membrane potential and morphological damage to the plasma membrane. Effects on other organelles are related to the loss of internal homeostasis of the parasite rather than to a direct effect of the peptide. Despite the fast kinetics of the process, the parasite is able to deactivate in part the effect of the peptide, as shown by the higher activity of the d-enantiomer of CA(1-8)M(1-18). Electrostatic interaction between the peptide and the promastigote membrane, the first event in the lethal sequence, is inhibited by polyanionic polysaccharides, including its own lipophosphoglycan. Thus, in common with bacteria, the action of CA(1-8)M(1-18) on Leishmania promastigotes has the same plasma membrane as target, but is unique in that different peptides show patterns of activity that resemble those observed on eukaryotic cells.

Adenosine Triphosphate↗
PubMed1998

Re-operative surgery for recurrent or persistent primary hyperparathyroidism.

BACKGROUND: While initial surgery for primary hyperparathyroidism, in experienced hands, will result in a cure in 98% of cases, re-operative surgery remains a significant challenge. Because attitudes as to who should perform initial exploration for hyperparathyroidism are significantly different around the world, the approach to re-operative surgery may also vary. The aim of the present study was to examine a local experience of re-operative surgery for recurrent or persistent primary hyperparathyroidism. METHODS: Information on indications for surgery, the procedure performed, pathology and complications of all re-operative procedures for primary hyperparathyroidism in the period January 1962 to December 1996 were obtained from a prospective database. RESULTS: Sixteen patients with persistent (n = 12) or recurrent (n = 4) primary hyperparathyroidism were treated in the unit over the study period. Eight patients had their initial operation within the unit at Royal North Shore Hospital and eight were referred from elsewhere for re-operation. Nine of the 12 patients with persistent hyperparathyroidism were cured by re-operation with failures due to spillage at first operation (n = 1) or failure to find any additional pathology (n = 2). All four patients with recurrent hyperparathyroidism were cured. All the failures occurred early in the learning phase of the unit, with a 100% cure rate for re-operative procedures performed in the last 15 years. The most common finding in patients referred from elsewhere with a failed initial operation was a missed inferior adenoma in association with the thymus. Localization studies had a variable sensitivity, with sestamibi scintigraphy, selective venous sampling and ultrasonography providing the most reliable information. CONCLUSIONS: Re-operative surgery for persistent or recurrent hyperparathyroidism is an uncommon procedure in Australia when compared to major centres in the USA. Successful surgery depends upon experience and an accurate knowledge of the embryology and anatomy of the parathyroid glands.

Adenoma↗
PubMed1996

Evidence for protective immunity to bancroftian filariasis in the Cook Islands.

To challenge the concept of protective immunity in lymphatic filariasis, 19 adult residents of a Wuchereria bancrofti-endemic island who had been diagnosed 17 years earlier as putatively immune endemic normals (PI/EN) were reexamined. Even with continued exposure to infection, all 19 had maintained their apparent infection-free status. Studies to define the mechanisms underlying this putative immunity revealed that cellular immune responses (including proliferation; generation of interleukin [IL]-2, IL-5, IL-10, interferon-gamma, and granulocyte-macrophage colony-stimulating factor) to adult- and microfilarial-stage antigens, but not antibody responses, were markedly greater than those of 20 age-matched, infected patients. Furthermore, the PI/EN group was comprised of high- and low-responding persons who were clinically indistinguishable. These findings provide evidence that protective immunity to lymphatic filariasis does occur and that it is probably T cell-mediated.

Adolescent↗
PubMed1996

Primary hyperparathyroidism in childhood and adolescence.

OBJECTIVE: The aim of this study was to determine the nature of the presentation and pathology of primary hyperparathyroidism in children and adolescents and to compare these findings with adults. METHODOLOGY: Data were obtained from the Thyroid Surgery Database at Royal North Shore Hospital on all children and adolescents undergoing parathyroid surgery. These results were then compared to data obtained from the last 100 consecutive adult parathyroidectomies. RESULTS: A total of eight younger patients underwent parathyroidectomy including three children (0-12 years) and five adolescents (13-18 years). A common presentation in the younger age group was hypercalcaemic crisis (50%) with a serum calcium > 3.5 mmol/L and clinical signs of calcium intoxication. This compared to the adult age group where only 8% presented with crisis (P < 0.05). Eighty-eight per cent of the younger patients complained of abdominal symptoms compared to only 1% of adults. Seven of eight young patients had sporadic hyperparathyroidism. CONCLUSIONS: Primary hyperparathyroidism, although uncommon in the younger age group, is still most commonly associated with sporadic tumours. Familial syndromes do not constitute a large percentage of patients. Younger patients are more prone to present late with abdominal symptoms, toxicity and hypercalcaemic crisis, presumably due to delayed diagnosis of an uncommon condition in this age group.

Adenoma↗
PubMed1995

Clearance of circulating filarial antigen as a measure of the macrofilaricidal activity of diethylcarbamazine in Wuchereria bancrofti infection.

Small doses of diethylcarbamazine (DEC) clear microfilariae (MF) from the blood of Wuchereria bancrofti-infected persons, but the dose and regimen required to kill adult worms is not clearly defined. A prospective study was undertaken to examine the macrofilaricidal effect of DEC and the ability of an assay for circulating filarial antigen (CFA) to define the effect. Twenty-five MF-positive subjects and 7 MF-negative but CFA-positive subjects were treated with DEC and followed for 18 months. Of the 25 MF-positive patients, 24 cleared MF, and 22 of 26 CFA-positive subjects cleared CFA. A significantly greater decrease in antifilarial IgG4 was seen in patients who cleared CFA than in those who did not. The complete clearance of CFA observed after therapy with DEC indicates that assessment of CFA clearance is a useful means for detecting macrofilaricidal effects of antifilarial chemotherapy.

Adolescent↗
PubMed1994

Long-term effect of prenatal exposure to maternal microfilaraemia on immune responsiveness to filarial parasite antigens.

To identify long-term effects of prenatal exposure to maternal filarial-parasite infection, we assessed lymphocyte responses in 21 Polynesian children born 17-19 years previously to mothers diagnosed as being microfilaraemic or infection-free. All children lived on an island endemic for bancroftian filariasis but were free from infection at the time of study. While children (n = 10) of infection-free mothers responded vigorously to microfilarial antigen with lymphocyte proliferation, production of interleukin 2 (IL-2), IL-5, IL-10, granulocyte macrophage colony-stimulating factor (GM-CSF), and interferon gamma (IFN-gamma), cellular hyporesponsiveness was seen in children (n = 11) born to microfilaraemic mothers. The hyporesponsiveness appeared restricted to microfilarial antigens and did not extend to non-parasite antigens. These findings suggest that hyporesponsiveness resulted from in-utero acquisition of tolerance to microfilarial antigens in chronically-infected mothers.

Adolescent↗
PubMed1977

The high prevalence of diabetes mellitus on a Central Pacific Island.

A diabetes prevalence study on an isolated urbanized Central Pacific Island has established a prevalence rate of 34.4% in individuals aged 15 years and over. Of these, 10.4% had previously known diabetes; in the others the diagnosis was made on the basis of a plasma glucose level of at least 160 mg/100 ml 2h after a 75 gm oral glucose load. A further 11.3% of the subjects had borderline diabetes as judged by a 2-h plasma glucose of between 140 and 159 mg/100 ml. Of the diabetics, 72% had a positive family history of diabetes. The high prevalence rate appears to be related to a number of factors including a diabetic genotype, urbanization, and obesity.

Adolescent↗
PubMedDate not supplied

Description of Opisthonecta matiensis n. sp. (Protozoa, Ciliophora), a new peritrich ciliate from wastewater.

Opisthonecta matiensis n. sp. was isolated from the inlet water of a wastewater treatment plant near Madrid, Spain, and studied in vivo, with silver methods, and using electronic and indirect immunofluorescence microscopy. This new species shows an amphora-like cell shape and has a size of 45-73 microns (x 58.2) x 25-40 microns (x 31.3). The oral infraciliature is formed by one haplokinety, three polykineties, and a short row of kinetosomes (epistomial membrane). The aboral infraciliature is made up of the trochal band and the scopula. From the trochal band arise three fibrillar systems: oral fibers, aboral fibers, and oblique fibers. The myoneme system is composed of a delicate peristomial ring, longitudinal branched fibers that reach the trochal band and of radial fibers extending from the scopula to the trochal band. The silverline system consists of an average of 147 lines. This new species is separated from other known forms by its smaller size, the presence of one single vacuole, and its higher number of silverlines.

Animals↗
PubMedDate not supplied

Morphology and infraciliature of a marine scuticociliate with a polymorphic life cycle: Urocryptum tortum n. gen., n. comb.

A new genus and species combination are proposed for Urocryptum tortum n. gen., n. comb., a scuticociliate with a polymorphic life cycle. This marine ciliate was isolated from a sample taken at Gokasho Bay in Mie Prefecture (Japan). Specimens from different phases of the growth cycle were examined in vivo and with two silver staining techniques. Three life-history stages were observed: an exponential growth phase stage (trophont), a stationary phase stage (tomite), and finally a resting stage (cyst). The exponential growth form is laterally flattened and ovoid; it has 20-24 somatic kineties (SK) and a typical complement of scuticociliate oral structures. Polykinetid 1 (Pk1) has two longitudinal files of 6 kinetosomes (Ks); sometimes one or two additional kinetosomes are located anteriorly. Polykinetid 2 (Pk2) has two files of 6 or 7 Ks; a third file of three widely spaced kinetosomes is located on its right side, as well as a small curved row of 5 Ks positioned on the right hand side of the posterior end of Pk2. Polykinetid 3 (Pk3) has 3 rows of 4, 5, and 7 Ks's perpendicular to the haplokinety (Hk) or paroral membrane. The stationary growth phase cell is spindle-shaped and has a similar number of SK that are much more closely spaced than in exponentially growing specimens. Oral infraciliary structures are reduced in size, having fewer kinetosomes and being positioned more anteriorly in the cell. Pk1 is composed of two files of 5-Ks, Pk2 has only two files of 6-7 Ks, and Pk3 has two to three rows of 3-4 Ks. The Hk is displaced anteriorly and becomes straight, losing the shape typical of exponential growth phase cells. Cysts are pyriform with a wide cyst wall; no infraciliary structures were visible.

Animals↗