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Biomedical subjects

L Bolt

Publications and source records attributed to L Bolt.

18 recordsLinked to original sources
PubMed2003

A comparison of planar scintigraphy and SPECT measurement of total lung deposition of inhaled aerosol.

Planar gamma camera imaging of inhaled aerosol deposition is extensively used to assess the total deposition in the lung. However, validation of the measurements is not straightforward, as gold standard measurements of lung activity against which to compare are not readily available. Quantitative SPECT imaging provides an alternative method for comparison. Four different methods for planar image quantification are compared. Two attenuation correction techniques, thickness measurement and transmission measurement, have been combined with two scatter correction techniques, reduced attenuation coefficient and line-source scatter function convolution subtraction. Each technique has been applied to 10 studies of aerosol deposition of a fine aerosol (mass median aerodynamic diameter 1.8 microm) and 10 studies using a coarse aerosol (mass median aerodynamic diameter 6.5 microm). The total activity in the right lung for each measurement has been compared to the value determined from SPECT imaging on the same subjects. When the thickness measurement and transmission techniques were applied with scatter compensation using a reduced attenuation coefficient, activity was systematically overestimated by 5% in both cases. The corresponding random errors (coefficient of variation) were 8.6% and 6.6%. Separate scatter correction reduced these systemic errors significantly to -1.5% and 2.7%, respectively. The random errors were not affected. All techniques provided assessment of total lung activity with an accuracy and precision that differed by less than 10% compared to the SPECT values. Planar gamma camera imaging provides a good method of assessing total lung deposition of inhaled aerosol.

Adult↗
PubMed2003

A randomised placebo controlled study to assess the effects of cholinergic treatment on muscarinic receptors in Alzheimer's disease.

OBJECTIVE: To determine the effects of cholinergic treatment on the muscarinic receptor in patients with Alzheimer's disease. METHODS: 12 patients with mild to moderate Alzheimer's disease and six controls were studied. The patients underwent ADAS-COG psychometric assessment and SPECT brain imaging with (123)I quinuclidinyl benzilate (QNB), to demonstrate the postsynaptic muscarinic M1 receptor, before being randomised in a double blind study to receive either an acetylcholinesterase inhibitor (donepezil) or placebo for four months. Following this, the ADAS-COG and the (123)I-QNB receptor scan were repeated. The controls were imaged on one occasion only. All image analyses were undertaken using SPM99. RESULTS: (123)I-QNB imaging showed a significant relation between baseline psychometric impairment and deficits on scanning. Both placebo and actively treated groups had reductions in (123)I-QNB uptake. Greater reductions in receptor binding were demonstrated in the placebo group than in those receiving active treatment. Intraindividual reproducibility of the (123)I-QNB imaging technique appeared highly robust. CONCLUSIONS: The results suggest that (123)I-QNB uptake is better preserved in Alzheimer's disease patients on cholinergic treatment than on placebo. Cholinergic treatment may play a neuroprotective role. Sequential (123)I-QNB imaging seems to be a powerful tool in monitoring the response of these receptors to disease modifying treatments.

Aged↗
PubMed2003

Alzheimer's disease: differences in technetium-99m HMPAO SPECT scan findings between early onset and late onset dementia.

OBJECTIVE: To compare the HMPAO SPECT cerebral perfusion patterns in early and late onset Alzheimer's disease. METHODS: Twenty patients with early onset disease (<65 years) and 44 patients with late onset disease (>65 years) were studied. All patients fulfilled NINCDS-ADRDA clinical criteria and had details of disease severity and length of history at the time of imaging. Technetium-99m HMPAO SPECT brain scans were acquired on a multi-detector gammacamera and analysed visually and with statistical parametric mapping (SPM99). RESULTS: Patients with early onset disease had significantly greater posterior cortical association area involvement whereas those with late onset disease had significantly greater medial temporal hypoperfusion. These findings were unchanged after controlling for disease severity and length of illness. DISCUSSION: These functional imaging findings of the differences between early and late onset Alzheimer's disease are supported by published findings that include histopathological and clinical evidence; namely late onset patients tend to present with the characteristic involvement of the medial temporal lobes producing marked memory loss whereas early onset patients present with predominant posterior cortical association area involvement. These age related findings should be borne in mind when clinically diagnosing, and interpreting functional brain imaging studies in, patients with suspected Alzheimer's disease.

Aged↗
PubMed2002

Measurement of cerebral perfusion volume and 99mTc-HMPAO uptake using SPECT in controls and patients with Alzheimer's disease.

Methods for quantifying the changes in brain function observed in single photon emission computed tomography (SPECT) using hexamethylenepropylene amine oxime (HMPAO) for patients with Alzheimer's disease have the potential of improving the diagnostic accuracy of the procedure and its ability to monitor response to treatment. The absolute percentage uptake of HMPAO and the cerebral perfusion volume (CPV) of the brain were assessed using SPECT in 26 patients with mild to moderate Alzheimer's disease (AD) and 24 control subjects. A subset of 15 control subjects, which was age-matched to the AD patients, was selected to allow fair statistical comparison of parameters between groups. The percentage of brain volume with reduced perfusion (R) and a volume loss index (VLI), given by /CPV, were also calculated. Eight of the control subjects were studied on a second occasion after a mean period of 6 months. There was no significant difference in percentage uptake between controls and AD patients, the mean value being 5.8%. Cerebral perfusion volume in controls was found to depend on sex (mean value in males and females being 1327 ml and 1222 ml, respectively) and on age. The volume loss index corrected for age and sex provided good discrimination between controls and AD subjects giving a sensitivity and specificity of 81% and 96%, respectively. The repeatability coefficient, the 95% confidence limit for the difference between repeat measurements, on controls was 67 ml (5%). The measurement of cerebral perfusion volume and related indices may be of value in identifying patients with early Alzheimer's disease and in following their response to treatment.

Adult↗
PubMed2001

Use of polypropylene prostheses for strangulated inguinal and incisional hernias.

We used monofilament polypropylene prostheses in 20 emergency operations for strangulated hernias. Sixteen of the operated patients had groin hernias (five of them recurrent), two had incisional and one had a Spigel's type hernia. Intestinal resection was performed because of bowel wall necrosis in one of the patients. During the postoperative period, we observed only one minor complication (a seroma formation). During the follow-up, no recurrence was observed. In our opinion, the use of monofilament polypropylene mesh in emergency hernia operations is safe, simple and effective.

Aged↗
PubMed2000

[Changing views in the 20-th century regarding acute appendicitis].

In 1886 Reginald H. Fitz described the pathology of acute appendicitis suggested surgical treatment. 10 years later, during VII-th the Congress of Polish Surgeons in Cracow, Maksymilian Rutkowski was the first in Poland to present the results of that kind of treatment. Operations performed for that frequently, not seldom fatal disease-were not accepted from the beginning through the world. In Poland as well at the beginning of the 20-th century, indications for appendectomy were discussed. In 1920 previous views regarding the necessity for surgical treatment in acute and chronic cases changed. These changes were supported by the observation that in some cases involving pain in the right, pain remains even after appendectomy were the vermiform appendix was found to be unaffected and it was also found that adhesion of ileus can be a dangerous late complications. It might appear that today's knowledge relating to this disease is fully established. Close observation found successful results as shown by in decreasing mortality. Within 100 years in the Massachusetts General Hospital mortality feel from 40% to 0.8% to Fitzs between patients who had undergone appendectomy accompany high percentage failed preoperative diagnosis. Today at the beginning of the 21-st century with the availability of MRI, CT, videosurgery and organs transplant it is difficult to imagine that the cause of such a common disease is still unknown and that in almost 1/4 of the operations performed on patients do not confirm the preoperative diagnosis.

Appendicitis↗
PubMed1999

A technique for manual definition of an irregular volume of interest in single photon emission computed tomography.

A technique is described for manually outlining a volume of interest (VOI) in a three-dimensional SPECT dataset. Regions of interest (ROIs) are drawn on three orthogonal maximum intensity projections. Image masks based on these ROIs are backprojected through the image volume and the resultant 3D dataset is segmented to produce the VOI. The technique has been successfully applied in the exclusion of unwanted areas of activity adjacent to the brain when segmenting the organ in SPECT imaging using 99mTc HMPAO. An example of its use for segmentation in tumour imaging is also presented. The technique is of value for applications involving semi-automatic VOI definition in SPECT.

3-Iodobenzylguanidine↗
PubMed1992

[Colonization with group B streptococcus in pregnant women taken into the care of unit K and hospitalized in the department of obstetric pathology].

Colonization with group B streptococci (GBS) in 714 pregnant women was investigated. Among 232 were hospitalised in department of pathological pregnancy and 512 were under ambulatory control. In 13.4% of hospitalised patients and 2.8% healthy pregnant women the colonization of vagina or throat with GBS was stated. The greatest percentage of vagina colonization was found in patients hospitalised in connection with gestosis or because of abortions, premature delivery and inanimate fetus. No correlation was found between range of GBS colonization and trimester of pregnancy. Almost all GBS strains proved to be susceptible for commonly used antibiotics but resistant to biseptol (88.2%). Patients of hospitalised group were more often colonized not only GBS but also other potentially pathogenic microorganisms.

Ambulatory Care↗
PubMed1991

Home detoxification from alcohol: its safety and efficacy in comparison with inpatient care.

The safety and short-term effectiveness of home detoxification (HD) was investigated by contrasting rates of treatment completion and of complications of 41 service users with those of a retrospectively matched inpatient comparison group. The latter comprised patients of a detoxification unit matched for age, sex and degree of alcohol dependence with HD subjects. HD subjects had severe problems with alcohol--they averaged 28.7 on the SADQ, 4.6 serious alcohol-related problems in the previous 2 months, a GGT of 123.8 and 174.6 reported units of alcohol consumed in the week before treatment. A high follow-up rate was achieved for both HD subjects and their relatives; there was close agreement between clients' reports, carers' reports and breathalyser readings with regard to further alcohol consumption. The HD subjects were visited at home an average of 6.9 times over 6.15 days. Chlormethiazole was prescribed in 36 cases at an average maximum daily dose of 6.3 capsules--significantly fewer than for the inpatient group. Both rates of completion and complication were virtually identical in the 2 groups. It is concluded that these data suggest HD is equivalent in both its safety and immediate efficacy to more expensive inpatient care.

Adult↗
PubMed1990

Home detoxification for problem drinkers: acceptability to clients, relatives, general practitioners and outcome after 60 days.

The value of a new Home Detoxification service was assessed in a variety of ways employing data collected from 41 clients of the service, their family and GP's. By 60 days from the start of treatment, 11 clients were abstinent, two were controlling their drinking with relatively few problems, 13 had 'improved', 14 were not 'improved' and one had an unknown outcome. Subsequent involvement in treatment by both clients and their partners was high in comparison with other studies. Significant predictors of 'Good' outcome included attendance for after-care by client and by spouse/partner and a low Alcohol Problems Inventory score. High levels of satisfaction were expressed with the HD service by clients, their carers and GP's. The great majority of clients gave 'home' as their preferred place of treatment and nearly half claimed they would have been unwilling to accept hospital care. There was evidence of significant, though modest, shifts in GP's management practices towards less use of hospitals and greater use of the patient's home after 15 months of the programme.

Adult↗