PET network abnormalities and cognitive decline in patients with mild cognitive impairment.

Temporoparietal and posterior cingulate metabolism deficits characterize patients with Alzheimer's disease (AD). A H(2)(15)O resting PET scan covariance pattern, derived by using multivariate techniques, was previously shown to discriminate 17 mild AD patients from 16 healthy controls. This AD covariance pattern revealed hypoperfusion in bilateral inferior parietal lobule and cingulate; and left middle frontal, inferior frontal, precentral, and supramarginal gyri. The AD pattern also revealed hyperperfusion in bilateral insula, lingual gyri, and cuneus; left fusiform and superior occipital gyri; and right parahippocampal gyrus and pulvinar. In an independent sample of 23 outpatients with mild cognitive impairment (MCI) followed at 6-month intervals, the AD pattern score was evaluated as a predictor of cognitive decline. In this MCI sample, an H2(15)O resting PET scan was carried out at baseline. Mean duration of follow-up was 48.8 (SD 15.5) months, during which time six of 23 MCI patients converted to AD. In generalized estimating equations (GEE) analyses, controlling for age, sex, education, and baseline neuropsychological scores, increased AD pattern score was associated with greater decline in each neuropsychological test score over time (Mini Mental State Exam, Selective Reminding Test delayed recall, Animal Naming, WAIS-R digit symbol; Ps<0.01-0.001). In summary, a resting PET covariance pattern previously reported to discriminate AD patients from control subjects was applied prospectively to an independent sample of MCI patients and found to predict cognitive decline. Independent replication in larger samples is needed before clinical application can be considered.     

Effect of naloxone on detrusor-sphincter dyssynergia in the chronic spinal cat

Naloxone, an opioid peptide antagonist, has been reported to facilitate voiding in neurologic bladder disorders, but its effects on the neural micturition reflex arc are poorly understood. We studied the effect of naloxone in 34 male adult cats, spinalized at C5-C6 level 7 to 119 days previously. Each cat served as its own control. The following tests were performed: Urethral pressure profiles, cystosphincterograms with the urethro-vesical junction opened and closed and mechanograms of the detrusor, and the circular and longitudinal urethral muscles. The study included (1) the effects of anesthesia of the bladder and pelvic nerve, as well as that of the urethral and pudendal nerves; (2) the action of naloxone; and (3) the action of oxymorphone. Our results demonstrated that naloxone (1) increased somatic (osteotendinous and nociceptive) reflexes and aggravated spasticity; (2) increased vegetative micturitional and sexual reflexes, in particular the urethra-urethral contraction reflex, aggravating the spasmodic contractions of the external sphincter; and (3) increased the frequency and intensity of the mass reflex. In consequence, we suggest that naloxone is contraindicated in cases of spinal cord lesions with detrusor-sphincter dyssynergia syndrome.     

Comparison of potency of human carcinogens: vinyl chloride, chloromethylmethyl ether and bis(chloromethyl)ether

The alpha-chloroether carcinogen chloromethylmethyl ether (CME) and its impurity bis(chloromethyl)ether (BCME) are direct-acting alkylating agents. Vinyl chloride (VC) is an indirect-acting carcinogen but its accepted carcinogenic intermediate, chloroethylene oxide, is also an alpha-chloroether. Both CME-BCME and VC have been in industrial use since about 1950. Hence, they were selected for comparison of potency as human carcinogens using numerous epidemiologic reports. There were 115 deaths due to angiosarcoma of the liver among several hundred thousand VC-exposed workers on the basis of reports from 10 countries during 1955 and 1984. Reports from five countries cited a total of 87 respiratory cancer deaths among only 3024 CME-BCME-exposed workers. If a recent court settlement in the United States is taken into account, the number of respiratory cancer deaths due to CME-BCME rises to 117. On the basis of these numbers of cancer deaths, and the levels and durations of exposure, it is concluded that VC is a weak human carcinogen compared to CME-BCME.     

P6 Complaints of halitosis related to the oral cavity. A preliminary report of 700 consecutive patients

Patients with complaints of halitosis do seek treatment from physicians and dental practitioners, because of the fear that their halitosis may interfere with their social activities. Although the prevalence of halitosis has been reported to be as high as 50%, most physicians and dental practitioners are poorly informed about the causes and treatments of halitosis. In order to care for patients with complaints of halitosis a multidisciplinary team was established at the Erasmus Medical Centre, Rotterdam, The Netherlands. The team included a dental hygienist, an otorhinolaryngologist, and a dentist, who developed a special halitosis programme. One short press release regarding the establishment of the team, was provided to the national press-centre. In the out-patient clinic more than 700 patients were seen by the team. Using a structured questionnaire fed to a PC, patients answered questions regarding complaints about the oral cavity, the upper respiratory tract, the throat, their general health, their cleansing habits of the oral cavity, and prior experiences with general physicians, dental practitioners, and medical specialists. They underwent examinations of the extent of their halitosis, of the perioral and neck region, the oral cavity, the upper respiratory tract, and the upper digestive tract. Finally, the members of the team came to a joint diagnosis and a joint treatment plan for every individual patient. Of the first 700 consecutive patients around 90% had a natural dentition without removable partial dentures. More than 60% were diagnosed as having periodontal disease with pockets of 4 mm or more in the maxilla. This figure was more than 50% in the mandible. Around 95% had tongue coating.     

Radiation therapy of benign diseases. What's new eight years after?]

The authors present an update version of the indications for radiotherapy in the management of benign diseases. This is based on available randomized trials and recent international meetings. Validated indications remain the prevention of resected heterotopic bone ossifications, kelo?ds scars and pterygium and also treatment of arteriovenous malformations; the place of radiotherapy for malignant exophtalmia is more and more restricted. Randomized trials have demonstrated the efficacy of endobrachytherapy in the prevention of restenosis after angioplasty but the use of embedded stent has replaced this indication. Macular degeneration is no more an indication of radiotherapy. Quality requirements for radiotherapy are identical for benign or malignant indications.     

Comparison between ankle and toe index in patients with peripheral arterial disease

In contrast to the systolic blood pressure at the posterior tibial artery, the evaluation of pressure at the digital artery of the foot before and after exercise in patients with peripheral arterial disease is not well known. Twenty three patients with peripheral vascular disease were examined. The systolic pressure was measured by means of an ultrasound velocity detector at the brachial and posterior tibial artery. Digital artery pressure was determined with photoplethysmography. Pressures were measured before and within 5 and 10 minutes after a treadmill test. Ankle and toe index was calculated. At rest the toe index is lower than the ankle index and after a treadmill test the decrease in toe index occurs in parallel to the ankle index.     

Ultrastructure of aberrant serotonin-immunoreactive fibers in the caudate putamen complex of the aged rat

Degeneration of neurons in the central nervous system is associated with morphological changes. Previous observations made at the light microscopical level indicated degeneration of serotonin-immunoreactive (IR) fibers in the aged rat brain. In this study, a comparison at the ultrastructural level was made between serotonin-IR normal thin and aberrant swollen varicose fibers in the caudate-putamen complex of the aged rat. Ultrastructural features such as the size and content of the thin varicose fibers resembled those in the caudate-putamen complex of the young rat as reported by others. The aberrant profiles were swollen, reaching a size of 6 microns. Their vesicles varied in size and were no longer uniformly round. Moreover, distorted mitochondria and membrane-filled vacuolelike structures were a common feature of the aberrant profiles. These changes are indicative of a degenerative process and give further evidence that, whereas many serotonergic fibers are preserved at high age, other serotonergic fibers are degenerating in the caudate-putamen complex of the aged rat.