Azolla cultivation enables phosphate extraction from inundated former agricultural soils.

To combat the global loss of wetlands and their essential functions, the restoration and creation of wetlands is imperative. However, wetland development is challenging when soils have been in prolonged agricultural use, often resulting in a substantial nutrient legacy, especially of phosphorous (P). Inundating these soils typically leads to P mobilization, resulting in poor water quality and low biodiversity recovery. As a potential novel means to overcome this challenge, we tested whether cultivation of the floating fern Azolla filiculoides could simultaneously extract and recycle P, and provide a commercial product. Azolla has high growth rates due to the nitrogen fixing capacity of its microbiome and is capable of luxury consumption of P. Azolla cultivation may also accelerate soil P mobilization and subsequent extraction by causing surface water anoxia and the release of iron-bound P. To test this approach, we cultivated Azolla on 15 P-rich former agricultural soils in an indoor mesocosm experiment. Soils were inundated and either left unvegetated or inoculated with A. filiculoides during two 8-week cultivation periods. Biomass was harvested at different intervals (weekly/monthly/bimonthly) to investigate the effect of harvesting frequency on oxygen (O2) and nutrient dynamics. We found that Azolla attained high growth rates only on soils with high mobilization of labile P, as plant cover did not reduce surface water O2 concentrations in the first phase after inundation. This concurred with low porewater iron to P ratios (<10) and high porewater P concentrations. A. filiculoides cultivation substantially reduced surface water nutrient concentrations and extracted P at rates up to 122 kg ha-1 yr-1. We conclude that rapid P extraction by A. filiculoides cultivation is possible on soils rich in labile P, offering new perspectives for wetland rehabilitation. Additional field trials are recommended to investigate long-term feasibility, seasonal variations, and the influence of potential grazers and pathogens.

Profile of CD4 counts and symptoms in HIV positive patients on and not on antiretroviral therapy.

This communication pertains to a study on analysis of the profile of CD4 counts and symptoms in HIV infected adult subjects on and not on antiretroviral therapy. Clinical symptoms in HIV infected patients attending a tertiary care hospital in north India were recorded by direct questioning. Differences in distribution of categorical variables were analyzed using chi-square test. A p-value < 0.05 was considered statistically significant. 317 enrolled HIV positive patients, 271/317 (85.5%) patients were symptomatic. The common symptoms were weakness (65.6%), bodyache and joint pain (63.4%), lethargy and fatigue (62.5%), prolonged fever (53.3%), weight loss (47.6%), cough (44.5%), loss of appetite (44.2%) and chronic diarrhoea (40.1%). Most symptoms were found significantly less frequently in patients on antiretroviral therapy (ART). High CD4+ T-cell counts were negatively associated with symptoms. The overall proportion of symptomatic patients was significantly higher than the number with an etiologically documented opportunistic infections (32.5%). Pulmonary tuberculosis (30.9%) was the most frequently documented opportunistic infection. Antiretroviral therapy appears to be beneficial in reducing symptoms in HIV positive patients. Affordable high quality laboratory diagnostic facilities for the diagnosis of opportunistic infections under the public health program will help to obtain an accurate picture of the range of opportunistic infections in HIV patients in India.

A peculiar case of HIV transmission within a family in north India.

SUMMARY: We describe an unusual case of heterosexual HIV transmission between two brothers within a family, due to a locally prevalent social custom of remarriage of the elder brother's widow, to the younger brother. This case of HIV secondary transmission, which could possibly have been stopped at certain points by better understanding and awareness about HIV transmission emphasizes the need for extensive post-test counselling of affected individuals and their family members.

Effect of iron chelators on paraquat toxicity in rats and alveolar type II cells.

There is general agreement that the lung damage seen in paraquat poisoning is due to the generation of free radicals in alveolar epithelial cells. We have recently shown that the iron chelator and antioxidant deferoxamine (DF) reduces the mortality caused by paraquat in vitamin-E-deficient rats. In the present study we investigated the effect of DF and the lipid soluble iron chelator compound 51 (CP51) of the hydroxypyridin-4-one family on paraquat poisoning in rats with a normal vitamin E status and on isolated alveolar type II cells (ATTC). Adult rats were intravenously injected with a lethal dose of paraquat (40 mg/kg) while concurrent treatment with a continuous intravenous infusion of DF or CP51 was started. Survival of rats receiving DF at 25 and 50 mg/kg/24 h was not significantly increased compared with PBS-treated control animals. CP51, however, significantly (p less than 0.01) reduced the mortality caused by paraquat. When rats were treated with 25 mg/kg/24 h, eight of 15 rats survived the study period of 35 days compared with three in the PBS-treated control group (n = 27). In ancillary in vitro studies radiolabeled [51Cr]ATTC were incubated in a medium containing 100 microM paraquat in the absence or presence of DF and CP51. Paraquat-induced ATTC lysis increased to approximately 25% after 7 h of incubation. At the highest tested concentration (500 microM) of chelator, injury decreased markedly (80%), whereas at the lowest tested concentration (50 microM) cytotoxicity was not prevented.(ABSTRACT TRUNCATED AT 250 WORDS)

Mechanism of protection of alveolar type II cells against paraquat-induced cytotoxicity by deferoxamine.

Paraquat toxicity has been associated with the generation of free radicals in alveolar epithelial cells in which paraquat specifically accumulates via a polyamine uptake system. In the present study we investigated whether deferoxamine (DF), an iron chelator that has antioxidant capacity and that also has a polyamine-like structure, could protect alveolar type II cells (ATTC) against injury by paraquat. Radiolabeled [3H]adenine ATTC were incubated in a medium containing 75 microM paraquat in the absence or presence of DF (500 microM). After 3 hr of incubation paraquat-mediated cytotoxicity of ATTC, as measured by [3H]adenine release, was significantly (P less than 0.005) decreased by addition of DF (26.6 +/- 2.6% vs 7.4 +/- 1.7%). Accumulation of radiolabeled [14C]paraquat at a concentration of 75 microM was also decreased (70%) by 500 microM DF from 94.8 +/- 2.1 to 28.9 +/- 6.7 nmoles paraquat/2.5 x 10(5) ATTC. This effect of DF was dose dependent and comparable with the protective effect of equimolar concentrations of putrescine. However, per cent uptake of paraquat at a concentration of 500 microM was not significantly inhibited by DF (1 mM), whereas paraquat-induced injury was still markedly reduced (36.2 +/- 2.5% vs 2.6 +/- 4.2%). This indicated that the protective effect of DF could not be explained by its competition with paraquat on uptake alone. In the same series of experiments using another iron chelator, pyridoxal benzoyl hydrazone (PBH), which has antioxidant properties similar to DF but does not show its polyamine-like structure, ATTC lysis was also prevented although paraquat uptake was not reduced. These in vitro data indicate that the mechanism of protection by DF against paraquat toxicity in lung epithelial type II cells is two-fold: inhibition of paraquat uptake through its compliance with the structural requirements necessary for transport, and inhibition of paraquat-induced iron-catalysed free radical generation.

A rapid and sensitive micro-assay to determine the capacity of quinones to undergo redox cycling.

Using a series of aziridinyl-benzoquinones it is shown that the conversion of oxyhemoglobin to methemoglobin in sheep erythrocytes is correlated with the capacity of each quinone to undergo redox cycling. Based on these findings a semiquantitative assay is developed for the rapid screening of redox cycling quinones.

Continuous intravenous infusion of deferoxamine reduces mortality by paraquat in vitamin E-deficient rats.

Paraquat, an oxygen radical-generating agent, is a widely used agrochemical that is also toxic for humans, in whom it may cause respiratory failure. In the present study, we investigated the effect of deferoxamine (DF), an iron chelator with antioxidant capacity, on paraquat toxicity in vitamin E-deficient rats. After the administration of paraquat at a dose of 20 mg/kg the animals were treated with a continuous intravenous infusion of DF for 14 days. In a dose-response study, four of six animals receiving 100 mg DF/kg/24 h survived the study period of 14 days compared with none in the saline-treated control group (n = 6), and three and two animals in the groups receiving 50 (n = 6) and 200 mg DF/kg/24 h (n = 6), respectively. In another series of experiments, animals were monitored for a total period of 35 days, at which time any survivors were killed, and lung histologic examination was carried out. Deferoxamine treatment was started simultaneously (n = 21), 6 h (n = 18), and 16 h (n = 18) after paraquat poisoning. Percent survival in the various time-point groups was 47.7 (p less than 0.01), 38.9 (p less than 0.02), and 22.2 (not significant), respectively, compared with 7.1 (n = 14) in the control group. The presence of lung damage was seen only in those of the surviving rats where DF was started at the 16 h time point after paraquat administration. In ancillary in vitro studies, where Escherichia coli was used as a source of enzymic activity for the redox-cycling of paraquat, DF completely inhibited the formation of hydroxyl radical (.OH).(ABSTRACT TRUNCATED AT 250 WORDS)

Morphometric study of pseudoepitheliomatous hyperplasia in granular cell tumors of the tongue.

Several reports have mentioned the possibility of misdiagnosing pseudoepitheliomatous hyperplasia (PEH) of the overlying mucosa of a granular cell tumor as a squamous cell carcinoma (SCC). Because of this, morphometry was applied to five granular cell tumors with PEH and five well-differentiated SCC of the tongue. In addition, ten normal tongues have been examined. The mean area, the mean perimeter and the mean diameter of the 50 largest squamous epithelial nuclei in 50 fields were found to be significantly larger in squamous cell carcinomas than in granular cell tumors and normal tongues. The shape factor of the nucleus and the mitotic activity appeared to be of no significant value in this respect.

Geographic stomatitis and psoriasis.

5 new cases of geographic stomatitis are presented and added to a review of 32 similar cases reported in the literature up to 1987. Furthermore, a series of 70 consecutive patients with psoriasis were examined for oral mucosal lesions. Based upon the findings of the literature and the results of the present study, there seems insufficient proof to consider geographic stomatitis an oral manifestation of psoriasis.

Use of whole cosmid cloned genomic sequences for chromosomal localization by non-radioactive in situ hybridization.

We report a general procedure which allows the application of whole cosmid cloned genomic sequences for non-radioactive in situ hybridization. The presence of highly repetitive sequences, like Alu and Kpn fragments, is eliminated through competition hybridization with Cot-1 DNA. The method has been tested and optimized with several randomly chosen cosmids of the human thyroglobulin (Tg) gene (8q24). At present, the procedure can be performed with three of the four tested individual cosmids. In cases where a single clone does not result in a specific signal, a larger fragment may be required, which can be accomplished by using two (partially overlapping) cosmids of the same region. The advantages and further potentialities of such a hybridization approach are discussed.

Osteoma or chondroma of the tongue; a clinical and postmortem study.

The occurrence of an osteoma or chondroma in the soft tissues of the oral cavity is rather uncommon. This anomaly occurs mainly on the tongue. Less than 60 cases have been published in the literature. In the first part of this treatise, 2 other patients are described, a 61-year-old female with a chondroma on the dorsum of the tongue and a 31-year-old female with an osteoma in the foramen caecum area. In the second part, the result of a post mortem study of 130 adult human tongues is reported. Not a single case of bone or cartilage formation was encountered in the cadaver tongues. The possible development of an osteoma or chondroma in embryonic life is discussed.

Thyroglossal cysts in patients over 30 years of age.

8 patients over 30 years of age with a thyroglossal cyst, who had not been operated on before and who underwent excision of the cyst by a Sistrunk procedure, are described. In 8 additional patients, a wait-and-see policy was adopted. Follow-up data of these 16 patients are reported 1.5-14 years after their last visit to the hospital. There were no recurrences in the group of treated patients. In the group of untreated patients, the cyst remained unchanged in 1, decreased in size in 3 and disappeared completely in the remaining 4 patients. The present study indicates that removal of a thyroglossal cyst in patients over 30 years of age is not obligatory.

Psychological aspects of patients with burning mouth syndrome.

This article reports the results of a psychological questionnaire survey of 184 patients who have burning mouth syndrome. The results are compared with normative data obtained in the Netherlands. In general, it may be concluded that in a large number of patients with glossodynia, psychological aspects such as anxiety, depression, and neurotic tendencies are of great importance. However, it must be emphasized that this conclusion may not be interpreted as support for a psychogenic cause of the syndrome or for a strong psychological factor in the etiology of glossodynia.

Non-radioactive in situ hybridization. A comparison of several immunocytochemical detection systems using reflection-contrast and electron microscopy.

A number of immunocytochemical detection systems for determining the chromosomal localization of specific nucleic acid sequences by non-radioactive in situ hybridization have been compared. The procedures were: 1. the peroxidase/diaminobenzidine (PO/DAB) combination, either or not gold/silver intensificated; 2. alkaline phosphatase marking using the nitro-blue tetrazolium plus bromochloro-indolyl phosphate substrate combination (AP/NBT + BCIP); and 3. immunogold with or without silver enhancement. The procedures were first tested and optimized in dot blot experiments and then applied to in situ hybridization. As hybridization probes, both a middle-repetitive and a unique sequence (modified with 2-acetylaminofluorene (AAF] were used. The advantages and disadvantages of the various methods for reflection contrast (RC) or transmission electron microscopic (TEM) visualization of hybrids are discussed.

Fine mapping of the Huntington disease linked D4S10 locus by non-radioactive in situ hybridization.

The chromosomal localization of a unique DNA fragment, closely linked to Huntington disease (HD), was assessed in situ by hybridization with 2-acetylaminofluorene (AAF) modified probes. In these experiments, a cosmid cloned genomic fragment (c5.5) was used for hybridization. Here we present evidence that confirms the mapping of the D4S10 locus to the p16 region of chromosome 4 and assigns it to the telomere of the short arm.

Lingual thyroid. A clinical and postmortem study.

3 patients with lingual thyroid are reported. In addition, 5 patients are described with hypothyroidism in whom functioning thyroid tissue was only present at the base of the tongue without any noticeable swelling. In a postmortem study of 120 tongues, not a single case of lingual thyroid was encountered. The preponderance of females among cases of congenital hypothyroidism and/or lingual thyroid is discussed.

Candida albicans in median rhomboid glossitis. A postmortem study.

To investigate the possible rôle of Candida in median rhomboid glossitis, the presence of Candida was looked for both in the foramen cecum area and the lateral borders of 100 human cadaver tongues. Almost equal %s were found in both locations. Although extrapolation of findings from postmortem material to normal subjects is somewhat hazardous, the results seem to question the importance of Candida in the etiology of median rhomboid glossitis.

Extrahypothalamic vasopressin and oxytocin in the human brain; presence of vasopressin cells in the bed nucleus of the stria terminalis.

In the present study, the distribution of extrahypothalamic vasopressin (VP) and oxytocin (OXT) in the human brain was investigated by means of immunocytochemistry. In the septum verum, few VP fibers were found in the nucleus septalis lateralis and medialis (NSL and NSM), and in the bed nucleus of the anterior commissure. Very few VP and OXT fibers were present in the amygdala and in the hippocampus, mainly around the rostral tip of the lateral ventricle on the level of the pes hippocampi. The locus coeruleus (LC) contained dense networks of VP fibers and, although to a lesser extent, OXT fibers over its entire rostrocaudal extension. VP-immunoreactive neurons were present in the bed nucleus of the stria terminalis in a number of subjects, while no OXT cells were found in this structure. Thus, the VP innervation of limbic structures in the human brain, in particular of the NSL, was found to be clearly less pronounced than in the rat brain. The VP innervation of the LC, by contrast, was denser in the human brain than in the rat brain. No sex differences were found in the VP innervation of the human brain. These findings stress the need for caution in extrapolation of data concerning peptidergic innervation of the rat brain towards the human brain.

Sensitive detection of hybridocytochemical results by means of reflection-contrast microscopy.

A new sensitive method for visualization of nonautoradiographic hybridization results in microscopic preparations is described. The method is based on the reflection of the incident light by diaminobenzidine precipitates deposited at the site of hybridization during an indirect hybridocytochemical procedure. The reflected light is detected by means of reflection-contrast microscopy. The applicability of the procedure is demonstrated with nucleic acid probes modified with 2-acetylaminofluorene groups. These in turn are localized in situ by an indirect immunoperoxidase reaction. Besides its sensitivity, this simple visualization technique possesses the additional advantages, over absorption and fluorescence microscopy, that it provides a total DNA counterstain and a chromosomal banding pattern.