Fitting methods for constructing energy-dependent efficiency curves and their application to ionization chamber measurements

An ionization chamber without and with an iron liner (absorber) was calibrated by a set of radionuclide activity standards of the Physikalisch-Technische Bundesanstalt (PTB). The ionization chamber is used as a secondary standard measuring system for activity at the Slovak Institute of Metrology (SMU). Energy-dependent photon-efficiency curves were established for the ionization chamber in defined measurement geometry without and with the liner, and radionuclide efficiencies were calculated. Programmed calculation with an analytical efficiency function and a nonlinear regression algorithm of Microsoft (MS) Excel for fitting was used. Efficiencies from bremsstrahlung of pure beta-particle emitters were calibrated achieving a 10% accuracy level. Such efficiency components are added to obtain the total radionuclide efficiency of photon emitters after beta decay. The method yields differences of experimental and calculated radionuclide efficiencies for most of the photon-emitting radionuclides in the order of a few percent.

Cellular expression of CCK-A and CCK-B/gastrin receptors in human gastric mucosa

Gastrin stimulates gastric acid secretion in various species, but the role of the structurally related CCK for the peripheral regulation of acid secretion in humans remains controversial. Moreover, species differences in CCK receptor function and expression have been reported. We therefore sought to identify the cellular targets of CCK and gastrin within the human gastric mucosa in situ. Gastric biopsies were collected from 15 patients without gastric disease. Expression of CCK receptor subtypes was detected in individual cells of the gastric mucosa by reverse transcription (RT)-PCR in situ, immunohistochemistry and confocal laser scanning microscopy, using antisera against the CCK-A or CCK-B/gastrin receptor subtype. Both CCK-A and CCK-B receptors were detected in antral and oxyntic mucosa at the mRNA and protein level. In fundic mucosa, CCK-A receptor mRNA and protein mapped to D cells (37.4+/-7.7). Besides, individual chief cells, mucous neck cells and parietal cells (12.3+/-4.7%) expressed CCK-A receptors. CCK-B/gastrin receptor mRNA and protein were detected in parietal cells (57.4+/-11.1%) and in neuroendocrine cells (33.2+/-4.4%) expressing chromogranin A. Furthermore, epithelial cells within the neck of the gastric gland were found to express the CCK-B/gastrin receptor. We conclude that (i) identification of CCK-A receptors on somatostatin producing D cells in humans provide the anatomical basis for a receptor-mediated mode of action of CCK on somatostatin release and (ii) detection of either CCK receptor subtype in the putative stem cell compartment implies a role of CCK in the maintenance of tissue homeostasis in human gastric mucosa.

[Intravenous thrombolytic treatment of acute basilar artery occlusion]

BACKGROUND

Acute stroke with basilar artery occlusion is a serious condition with high mortality and severe disability.

MATERIAL AND METHODS

We describe three patients with acute artery basilar occlusion treated with thrombolytic agent given intravenously.

RESULTS

One patient demonstrated early and considerable clinical improvement parallel to thrombolytic therapy started two and a half hour after ictus, but suffered a new occlusion and died in a "locked-in syndrome". One patient demonstrated moderate clinical improvement after less than six hours and survived with disability. One patient demonstrated no clinical improvement with thrombolytic therapy started six hours after ictus and later died of an injured brainstem. No patients had serious bleeding.

INTERPRETATION

Intravenous, systemic thrombolytic treatment may have a beneficial effect in acute basilar occlusion.

Identification of CCK-B/gastrin receptor splice variants in human peripheral blood mononuclear cells

There is increasing evidence for a direct interaction of the enteric nervous and immune system. Receptors for neuropeptides such as VIP, somatostatin, and substance P have been characterised in human immuno-haematopoietic cells but little is known about the functional significance and expression of receptors for cholecystokinin (CCK) on cells of the immune system. There are only few studies that describe the expression of CCK receptors on human leukaemia-derived cell lines but the receptor structure and function in normal leukocytes have not been clearly established. We therefore sought to determine CCK receptor expression, structure, and function in nontransformed human peripheral blood mononuclear cells.Full-length cDNA clones encoding the human CCK-A and CCK-B/gastrin receptor are expressed in peripheral blood mononuclear cells from healthy volunteers without haematopoietic malignancy. In addition to wild-type CCK-B/gastrin receptor cDNAs, we isolated a splice variant with an in frame insertion of 69 amino acids within its putative third intracellular receptor loop. Dideoxy sequence analysis revealed that the cDNA of this splice variant comprises exons 1-4 but retains intron 4 (207 bp) in the absence of mutations within the splice donor sites. Transient expression of this splice variant in COS-7 cells reveals wild-type affinity for CCK-8, Gastrin-17, and antagonist L-365,260. Affinity for glycine-extended gastrin-17 was not increased when compared to the wild-type CCK-B/gastrin receptor. In vitro, gastrin decreased 3H-thymidine labelling in phytohaemagglutinin-pretreated mononuclear cells at a half-maximally effective concentration of 1.5 nM. We also isolated a cDNA encoding another splice variant of the CCK-B/gastrin receptor with a 158 bp deletion of the entire exon 4 sequence. We conclude that wild-type transcripts of both CCK receptor subtypes and splice variants of the CCK-B/gastrin receptor are expressed in nontransformed human mononuclear cells and that gastrin exhibits antiproliferative effects.

Standardisation and decay data of 177Lu and 188Re

The activity values of 177Lu and 188Re standard sources were measured using the 4pibeta-gamma-coincidence method and by liquid scintillation counting. The X- and gamma-ray emission probabilities per disintegration were determined by means of photon spectrometry with calibrated Ge and Si(Li) detectors and using the pertinent activity values. The half-lives were measured with ionization chambers, yielding T(1/2)(177Lu) = 6.646(5) d and T(1/2)(188Re) = 0.70848(9) d.

The late whiplash syndrome: a biopsychosocial approach

Physicians and other therapists continue to grapple in daily practice with the controversies of the late whiplash syndrome. For decades much of the debate and the approach to this controversial syndrome has centred on the natural history of and progression to chronic pain after acute whiplash injury. Recognising that there is recent epidemiological data that defines the natural history of the acute whiplash injury outside of many of the confounding factors occurring in many western countries, and the lack of evidence for a "chronic whiplash injury", this article will thus introduce the biopsychosocial model, its elements, its advantages over the traditional model, and the practical application of this model. The biopsychosocial model recognises physical and psychological sources of somatic symptoms, but fundamentally recognises that the late whiplash syndrome is not the result of a "chronic injury".

Prophylactic treatment of migraine with angiotensin converting enzyme inhibitor (lisinopril): randomised, placebo controlled, crossover study

OBJECTIVE

To determine the efficacy of an angiotensin converting enzyme inhibitor in the prophylaxis of migraine.

DESIGN

Double blind, placebo controlled, crossover study.

SETTING

Neurological outpatient clinic.

PARTICIPANTS

Sixty patients aged 19-59 years with migraine with two to six episodes a month.

INTERVENTIONS

Treatment period of 12 weeks with one 10 mg lisinopril tablet once daily for one week then two 10 mg lisinopril tablets once daily for 11 weeks, followed by a two week wash out period. Second treatment period of one placebo tablet once daily for one week and then two placebo tablets for 11 weeks. Thirty participants followed this schedule, and 30 received placebo followed by lisinopril.

MAIN OUTCOME MEASURES

Primary end points: number of hours with headache, number of days with headache, number of days with migraine. Secondary end points: headache severity index, use of drugs for symptomatic relief, quality of life and number of days taken as sick leave, acceptability of treatment.

RESULTS

In the 47 participants with complete data, hours with headache, days with headache, days with migraine, and headache severity index were significantly reduced by 20% (95% confidence interval 5% to 36%), 17% (5% to 30%), 21% (9% to 34%), and 20% (3% to 37%), respectively, with lisinopril compared with placebo. Days with migraine were reduced by at least 50% in 14 participants for active treatment versus placebo and 17 patients for active treatment versus run-in period. Days with migraine were fewer by at least 50% in 14 participants for active treatment versus placebo. Intention to treat analysis of data from 55 patients supported the differences in favour of lisinopril for the primary end points.

CONCLUSION

The angiotensin converting enzyme inhibitor, lisinopril, has a clinically important prophylactic effect in migraine.

[Polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy]

BACKGROUND

Polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy (Nasu-Hakola syndrome) (PLO-SL) is an unusual cause of early dementia in which the decline in cognitive function is associated with multiple bone cysts, in particular in hands and feet. About 165 cases of this autosomal recessive hereditary disease have been reported worldwide, mostly from Finland and Japan.

MATERIAL AND METHODS

In this article, case histories of PLO-SL are presented of two brothers who were born to consanguineous parents on an island outside the western coast of Norway. They are the 3rd and 4th patients in Norway described with this disorder.

RESULTS

One of the brothers was diagnosed retrospectively and the diagnosis was not made in the other even when he had fractures without entirely adequate trauma.

INTERPRETATION

It is suspected that the disease is underdiagnosed. For this reason, all patients with polycystic lesions in the skeleton should be evaluated for their mental state and all patients with an etiologically unclear dementia before the age of 50 should be investigated with x-rays of hands and/or feet.

Prevalence of temporomandibular disorders associated with whiplash injury in Lithuania

OBJECTIVE

The purpose of this study was to ascertain the prevalence of symptoms of temporomandibular disorders in whiplash victims in Lithuania and compare it with the prevalence in otherwise healthy control subjects.

STUDY DESIGN

In a controlled historical cohort study in Lithuania, we asked each of 210 victims of vehicular rear-end collisions (at 14-27 months after the accident) to report the presence and frequency of a number of temporomandibular disorder symptoms. The results were compared with those for an age-matched and gender-matched control group, sampled randomly from the local population.

RESULTS

In the accident group, 2.4% of subjects (4/165) reported jaw pain for 1 day or more per month; this compared with 3.3% of the controls (6/180). One (0.6%) of the accident victims and 2 (1.1%) of the controls had daily jaw pain. In both groups there was a low prevalence of jaw sounds, pain in or near the ear(s), jaw locking, tinnitus, and facial pain.

CONCLUSIONS

Unlike whiplash claimants in many Western societies, Lithuanian accident victims do not appear to report the chronic symptoms of temporomandibular disorders despite their acute whiplash injuries.

The best approach to the problem of whiplash? One ticket to Lithuania, please

The Quebec Task Force (QTF) on Whiplash Associated Disorders (WAD)--1995--sent a clear message that we need to re-evaluate the basis for our treatment strategies, and in particular place more emphasis on research to better define these strategies. Judging by many of the clinical strategies currently in use, the Task Force recommendations seem to have been largely ignored three years later. A further compelling reason to re-evaluate our current practices at this time is the finding of much more rapid recovery rates in some cultures, even with little or no therapy. This commentary is a frank consideration of the therapeutic community's responsibility to not only help solve the dilemma of whiplash, but also avoid contributing to the problem. We thus explore a new biopsychosocial model of whiplash, considering the effects of symptom expectation, amplification, and attribution in chronic pain reporting. Based on that model we propose a treatment strategy, and conclude that such strategies provide the only viable approach to this medicolegal and social dilemma.

Pain after whiplash: a prospective controlled inception cohort study

OBJECTIVES

In Lithuania, there is little awareness of the notion that chronic symptoms may result from rear end collisions via the so-called whiplash injury. After most such collisions no contact with the health service is established. An opportunity therefore exists to study post-traumatic pain without the confounding factors present in western societies.

METHODS

In a prospective, controlled inception cohort study, 210 victims of a rear end collision were consecutively identified from the daily records of the Kaunas traffic police. Neck pain and headache were evaluated by mailed questionnaires shortly after the accident, after 2 months, and after 1 year. As controls, 210 sex and age matched subjects were randomly taken from the population register of the same geographical area and evaluated for the same symptoms immediately after their identification and after 1 year.

RESULTS

Initial pain was reported by 47% of accident victims; 10% had neck pain alone, 18% had neck pain together with headache, and 19% had headache alone. The median duration of the initial neck pain was 3 days and maximal duration 17 days. The median duration of headache was 4.5 hours and the maximum duration was 20 days. After 1 year, there were no significant differences between the accident victims and the control group concerning frequency and intensity of these symptoms.

CONCLUSIONS

In a country were there is no preconceived notion of chronic pain arising from rear end collisions, and thus no fear of long term disability, and usually no involvement of the therapeutic community, insurance companies, or litigation, symptoms after an acute whiplash injury are self limiting, brief, and do not seem to evolve to the so-called late whiplash syndrome.

Headache after whiplash: a historical cohort study outside the medico-legal context

Headache is frequently reported as a chronic complaint after whiplash traumas. Criteria have been presented, but it has not been validated whether any specific headache type emerges after a trauma with whiplash mechanism. In a questionnaire-based historical cohort design, 202 adult Lithuanian individuals were interviewed 1-3 years after experiencing a rear-end car collision. The questionnaire was designed so that a diagnosis of migraine and tension-type headache in accordance with the International Headache Society criteria could be made. "Possible cervicogenic headache" was diagnosed according to Sjaastad et al.'s minimal criteria. The diagnostic panorama in those with traumas was compared with that of an age- and sex-matched control group. The introductory questions did not reveal differences in headache frequencies between the traumatized and control groups (p = 0.60). The prevalence of migraine and tension-type headache (both episodic and chronic) was also similar. A higher frequency of possible cervicogenic headache was observed in the traumatized group (10 vs 5), but the difference was not statistically significant (p = 0.28). Sixteen patients in the accident group had headache > 15 days per month, 11 of the 16 had similar complaints before the trauma, while 5 had worsened headache as compared to (the recollected headache) before the trauma. None of the patients with possible cervicogenic headache reported increased headache after the accident. Accordingly, the present results obtained outside the medico-legal context do not confirm that a specific headache pattern emerges 1-3 years after a rear-end car collision.

MMPI profiles in post-lumbar puncture headache

From the original material of 300 patients, of whom 37.3% had experienced a post-lumbar puncture headache (PPH), a total of 20 males and 50 females were evaluated with the Minnesota Multiple Personality Inventory (MMPI). The test was administered on average 33 months after the lumbar puncture (range 13-51), at a time when anxiety and depression related to the original investigation for a possible organic neurologic disease were expected to affect the results minimally. In the present material PPH was experienced by 45.7% of the patients, 40% of the males, and 48% of the females. Patients without PPH were used as controls. The selected material was a representative sample of the original material both as to distribution of age, proportion of organic diagnoses, and frequency of PPH. The MMPI disclosed no statistically significant differences between PPH patients and controls regarding personality traits.

Natural evolution of late whiplash syndrome outside the medicolegal context

BACKGROUND

In Lithuania, few car drivers and passengers are covered by insurance and there is little awareness among the general public about the potentially disabling consequences of a whiplash injury. We took this opportunity to study the natural course of head and neck symptoms after rear-end car collisions.

METHODS

In a retrospective questionnaire-based cohort study, 202 individuals (157 men; 45 women) were identified from the records of the traffic police department in Kaunas, Lithuania. These individuals were interviewed 1-3 years after experiencing a rear-end car collision. Neck pain, headache, subjective cognitive dysfunction, psychological disorders, and low back pain in this group were compared with the same complaints in a sex-matched and age-matched control group of uninjured individuals selected randomly from the population register of the same geographic area.

FINDINGS

Neck pain was reported by 71 (35% [95% CI 29-42]) accident victims and 67 (33% [27-40]) controls. Headache was reported by 107 (53% [46-60]) accident victims and 100 (50% [42-57]) controls. Chronic neck pain and chronic headache (more than 7 days per month) were also reported in similar proportions (17 [8.4%; 5-13] vs 14 [6.9%; 4-12] and 19 [9.4%; 6-15] vs 12 [5.9%; 3-10]) by the two groups. Of those who reported chronic neck pain or daily headache after the accident, substantial proportions had had similar symptoms before the accident (7/17 for chronic neck pain; 10/12 for daily headache). There was no significant difference found. No one in the study group had disabling or persistent symptoms as a result of the car accident. There was no relation between the impact severity and degree of pain. A family history of neck pain was the most important risk factor for current neck symptoms in logistic regression analyses.

INTERPRETATION

Our results suggest that chronic symptoms were not usually caused by the car accident. Expectation of disability, a family history, and attribution of pre-existing symptoms to the trauma may be more important determinants for the evolution of the late whiplash syndrome.

[Sleep disorders]

There has been a great development in sleep medicine during the past 20-25 years and the International Classification of Sleep Disorders now lists about 90 relatively well-defined conditions related to sleep. Several of them are severely underdiagnosed. This review considers frequent and/or disabling sleep disorders, in particular disorders for which treatment is available.