A 25-year retrospective analysis of factors influencing success of aluminum treatment for lake restoration.

For more than 50 years, aluminum (Al)-salts have been used with varying degrees of success to inactivate excess mobile phosphorus (P) in lake sediments and restore lake water quality. Here, we analyzed the factors influencing effectiveness and longevity of Al-treatments performed in six Swedish lakes over the past 25 years. Trends in post-treatment measurements of total phosphorus (TP), Chlorophyll a (Chl_a), Secchi disk depth (SD) and internal P loading rates (Li) were analyzed and compared to pre-treatment conditions. All measured water quality parameters improved significantly during at least the first 4 years post-treatment and determination of direct effects of Al-treatment on sediment P release (Li) was possible for three lakes. Improvements in TP (-29 to -80%), Chl_a (-50 to -78%), SD (7 to 121%) and Li (-68 to -94%) were observed. Treatment longevity, determined via decreases in surface water TP after treatment, varied from 7 to >47 years. Lake type, Al dose, and relative watershed area were related to longevity. In addition, greater binding efficiency between Al and P was positively related to treatment longevity, which has not previously been shown. Our findings also demonstrate that adequate, long-term monitoring programs, including proper determination of external loads, are crucial to document the effect of Al-treatment on sediment P release and lake water quality.

Release of organic P forms from lake sediments.

The effects of different physical and chemical conditions on the decomposition and release of organic and inorganic P compound groups from the sediment of Lake Erken were investigated in a series of laboratory experiments. Conditions investigated were temperature, oxygen level, and the effects of additions of carbon substrate (glucose) and poison (formalin). The effects on the P compound groups were determined by measurements with (31)P NMR before and after the experiments, as well as analysis of P in effluent water throughout the experiment. Phosphate analysis of the effluent water showed that oxygen level was the most influential in terms of release rates, with the sediments under anoxic conditions generally releasing more phosphate than the other treatments. (31)P NMR showed that the various treatments did influence the P compound group composition of the sediment. In particular, the addition of glucose led to a decrease in orthophosphate and polyphosphate while the addition of formalin led to a decrease in phosphorus lipids, DNA-phosphate and polyphosphate. Oxic conditions resulted in an increase in polyphosphates, and anoxic conditions in a decrease in these. Temperature did not seem to affect the composition significantly.

Regulation of dopaminergic activity in early Parkinson's disease.

Parkinson's disease (PD) is characterized by an uneven and progressive loss of nigrostriatal dopaminergic neurons. It is hypothesized that the physiological basis for the therapeutic response in early stages of PD is the ability for the partially and unevenly denervated dopaminergic system to restore and normalize dopaminergic influence in functionally segregated subregions of the basal ganglia. To investigate this hypothesis, patients with early and uncomplicated PD were investigated with positron emission tomography by using a two-tracer protocol yielding a measure of dopamine transporter-corrected dopamine synthesis capacity. Compared with controls, patients with PD exhibited a considerable increase in dopamine transporter-corrected dopamine synthesis capacity. The increase showed an inverse dependence on the structural integrity in as much as the highest rate was measured in the most denervated region, the dorsal part of putamen (198% of control value). A therapeutic challenge with antiparkinsonian medication state-dependently decreased dopaminergic activity. Thus, it is demonstrated that dopaminergic degeneration in PD is accompanied by a conspicuous acceleration of presynaptic dopaminergic activity, which is state-dependently down-regulated by dopaminomimetic treatment. It is suggested that homeostatic mechanisms acting to maintain congruity within the dopaminergic system are functionally intact in early PD.

Neurological signs and psychomotor performance in patients with schizophrenia, their relatives and healthy controls.

Schizophrenic patients (DSM-III-R) were consecutively recruited and 39 were included. Twenty-one were first-episode and 18 were chronic schizophrenic patients. Thirty of the patients were on neuroleptic medication. Thirty-three parents were included, of whom nine were classified as 'family history positive' and 22 as 'family history negative' of a disposition to psychosis. Fifty-five healthy controls volunteered. The subjects were investigated according to a protocol divided into neurological signs and psychomotor performance (finger-tapping rate, Purdue pegboard test, pronation-supination test, gait and hand-grasp strength). Seventy-eight percent of the patients and 7% of the controls were classified as globally aberrant in signs. The patients and their parents, classified as 'family history positive', exhibited a similar laterality pattern in a finger-tapping test improving performance with the preferred hand, significantly different from the performance of the 'family history negative' parents and normal subjects. Duration of illness, neuroleptic medication and negative symptoms were not related to the occurrence of neurological signs and psychomotor performance. These findings indicate that neurological aberrations are present at the onset of illness and that hereditary factors are associated with motor laterality.

Dopamine autoreceptor function is lost in advanced Parkinson's disease.

OBJECTIVE: Regional presynaptic dopaminergic function and its regulation by dopamine agonists in different stages of PD can be measured by L-[11C]dopa and PET. In the current investigation, we studied the effects of therapeutic apomorphine on L-[11C]dopa uptake in patients with early and advanced PD. BACKGROUND: With disease progression and chronic dopamine agonist treatment, motor response complications supervene in a majority of PD patients. It is assumed that both presynaptic and postsynaptic changes in the dopaminergic system act to modify dopaminergic efficacy. METHODS: Patients with early and advanced stages of PD were included in the study. All patients were investigated twice with PET and L-[11C]dopa drug free and during a subsequent standardized therapeutic apomorphine infusion. RESULTS: Subregional analysis of the striatum showed differences in the effects of apomorphine infusion on the L-[11C]dopa influx rate in the two patient categories. In patients with early and uncomplicated PD, apomorphine infusion decreased the L-[11C]dopa influx rate. This decrease was most pronounced in the dorsal part of the putamen. In advanced PD patients, apomorphine did not affect the striatal L-[11C]dopa influx rate. CONCLUSIONS: We suggest that in mild and stable PD an upregulated presynaptic inhibitory feedback regulation, particularly in the dorsal putamen, acts to maintain congruity within the dopaminergic system in response to antiparkinsonian medication. However, this inhibitory feedback regulation is diminished with the progression of nigrostriatal degeneration and chronic dopamine agonist treatment.

Violent and nonviolent suicide attempts--a controlled Rorschach study.

Rorschach records from 20 patients who had made active, violent suicide attempts were compared with records from 20 patients who had taken drug overdoses and 20 psychiatric control patients who had not made a suicide attempt. Ego function ratings showed that violent attempters were more paranoid than both other groups and less able to cope with conflict situations, to handle dysphoric affect and to differentiate between reality and imagination. Violent attempters had lower level of cognitive maturity than controls and tended to produce fabulized combination responses, suggesting cognitive slippage, and distorted human content responses, indicating pathological object relationships. Nonviolent attempters did not differ from controls. Six patients, all from the violent attempt group, completed suicide within a follow-up period of 4 years. Compared with the survivors, they were less tolerant of dysphoric affect and showed more pronounced decline of developmental level within cards. Completers could be identified on the Rorschach at 55% sensitivity and 93% specificity.

The relative frequency of periapical lesions in teeth with root canal-retained posts.

This study was concerned with the relation between technical quality of root filling seal in teeth with posts and radiographic status of the periapical tissues. Full-mouth series from 298 randomly chosen patients were examined by two observers. Endodontic treatment had been performed in 852 roots and posts were observed in 424 of these. Periapical radiolucencies were judged to be present in 16% of roots with posts and in 13% of roots without posts. Roots with posts in which the remaining root filling was shorter than 3 mm showed a statistically significant higher frequency of periapical radiolucencies (p less than 0.01). It was found that an improper seal was more unfavorable in roots with posts (p less than 0.05). The findings in this study indicate that the placement of a post will not per se decrease the probability of periapical healing. It also suggests that the remaining root filling must not be shorter than 3 mm.

Aspects of personality in patients with anxiety disorders undergoing capsulotomy.

Capsulotomy is an established psychosurgical intervention for anxiety disorders. While the effectiveness of the intervention in reducing target symptoms is undisputed, the issue of negative personality changes following capsulotomy is of great concern. We studied prospectively personality traits in nine consecutive patients undergoing capsulotomy for anxiety disorder, using the Rorschach test and a personality inventory, the Karolinska Scales of Personality (KSP), administered before and one year after operation. The protocols were evaluated under blind conditions by an independent assessor who had access to no data other than the age and sex of the patients. The Rorschach findings were used in two main comparison procedures: between the patients pre- and postoperative scores, and between that group and three reference groups. The KSP data were compared both with an age-stratified non-patient control group and with data obtained from groups of neurotic patients. In summary, the capsulotomy patients' personalities, as expressed in their Rorschach interpretations, remained intact, and significant reductions were noted in scales reflecting anxiety and hospitality. Statistically significant changes were also noted after operation in 10 of the 17 scales included in the KSP. While pathological scores were observed preoperatively in many scales, all the postoperative scores but one (Socialization) were within the normal range. Scores on the Socialization scale remained low, which is often the case in chronic patients. It is concluded that the patients displayed more normal personality features after operation than before and that adverse personality changes are not likely to occur after capsulotomy.

Prediction of outcome after cardiac arrest.

Neurologic outcome of hypoxic ischemic coma after cardiac arrest was studied in 32 patients. Observations were made and samples collected 24 and 48 h after the ischemic insult. The Glasgow-Pittsburgh coma score was assessed for its prognostic value. Other variables studied were the EEG and adenylate kinase, lactate and glutathione in the cerebrospinal fluid (CSF). Outcome was termed good if the patients resumed an independent life within a 6-month follow-up period. The closest correlations between prediction and good outcome occurred with the Glasgow-Pittsburgh coma score (94%) and the EEG (77%) at the 48-h examination, a modified coma score (96%) at 48 h, and CSF lactate (78%) at 24 h. Some simple neurologic signs (e.g., no withdrawal response to pain) at stated points in time was 100% associated with a bad outcome, although their absence was not associated necessarily with a good prognosis.

Cholinesterase inhibitors lack therapeutic effect in amyotrophic lateral sclerosis. A controlled study of physostigmine versus neostigmine.

Seven patients with amyotrophic lateral sclerosis participated in a double-blind cross-over trial of oral physostigmine and neostigmine (10 and 45 mg/day, respectively, for 3 days). Six of the patients were also given intravenous injections (1 and 1.5 mg, respectively) of the drugs in an open trial. No significant effects on muscle strength or neurophysiological parameters were observed.

Rorschach ratings in depressed and suicidal patients with low levels of 5-hydroxyindoleacetic acid in cerebrospinal fluid.

In order to explore the psychodynamics of a previously observed association between a low concentration of the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) in cerebrospinal fluid (CSF) and an increased tendency to suicidal behavior, blind ratings of Rorschach variables were compared between depressed and/or suicidal patients with low (less than 80 nanomoles/l) and normal (greater than 80 nanomoles/l) CSF 5-HIAA. In 14 patient pairs matched for sex, age, body height, and interview-based ratings of severity of depression, the low 5-HIAA subjects had significantly more anxiety and more hostility in the Rorschach ratings. Their anxiety tolerance was lower, and they were significantly less efficient in their handling of conflict. The results support the hypothesis that biochemical variables may be of importance for certain psychodynamic mechanisms suggested to be relevant for psychopathology, including suicidal behavior.

Cystometry and mictometry as tools in diagnosing neurogenic impotence.

Thirty-six males with erective impotence underwent neurological and urological examinations. Six of the patients were known to have a neurological disorder at the time of referral (four multiple sclerosis, one myelomeningocele, one diabetic polyneuropathy). Four further cases of neurological disorders were found (one multiple sclerosis, one myelopathy of unknown cause, one Shy-Drager syndrome, one sequelae of sacral herpes zoster). Five of these 10 patients gave a history of urinary troubles, but in all of them objective signs of bladder dysfunction were found at cystometry and/or mictometry. Among the 26 patients with impotence and no indication of a neurological disorder all invariably had normal cystometrograms, though some had abnormal mictiograms, probably due to local urological disorders. A neurological examination should be included in the evaluation of patients with erective impotence. Cystometry and mictometry may be of value by giving additional indications that the impotence is neurogenic. This is explained by the fact that the anatomical structures regulating sexual function lie close to corresponding structures regulating bladder function at the spinal level.