Delayed neuropathy and acute toxicity studies with pirimiphos-methyl in the hen

This paper describes studies aimed at determining the acute anticholinergic and delayed neurotoxic potential of the organophosphate insecticide pirimiphos-methyl (O-2-diethylamino-6-methylpyrimidin-4-yl O,O-dimethyl phosphorothioate) in the hen. Delayed neuropathy was assessed by biochemical measurement of neuropathy target esterase (NTE) activities in the brain and spinal cord, clinical signs of neuropathy over two 21-day periods and histological assessment of nervous tissue. Acetylcholinesterase (AChE) activity was also determined in the brain and spinal cord. Hens were given a single oral dose of 100 mg kg-1 pirimiphos-methyl, which was followed by a repeated dose after 21 days. Tri-o-cresyl phosphate (TOCP), 500 mg kg-1, was used as a positive control. All pirimiphos-methyl-treated hens received prophylactic doses of N-methylpyridinium-2-aldoxime methanesulphonate (P2S) and atropine sulphate. Hens dosed with pirimiphos-methyl had very low AChE activities (less than 20% of control) in both the brain and spinal cord, 24 and 48 h after dosing. In the TOCP-treated hens, the activities were about 90% of control. NTE activities in the brain and spinal cord of pirimiphos-methyl-treated hens were identical to those in the controls, while they were profoundly inhibited (greater than 80%) in the TOCP-treated hens. All hens dosed with pirimiphos-methyl showed the expected signs of AChE inhibition and, following recovery, usually by Day 5, no clinical signs of delayed neuropathy were seen. The TOCP-treated hens developed clinical signs of neuropathy.(ABSTRACT TRUNCATED AT 250 WORDS)     

Milk consumption in older Americans.

OBJECTIVES: The purpose of this study was to identify individual characteristics associated with types and frequency of milk consumption in older American adults. METHODS: A national probability-based sample (response rate = 91%) completed a telephone survey. Generalized logit and cumulative logit analyses were used to identify predictors of and barriers to fluid milk consumption in 494 elderly people. RESULTS: The likelihood of drinking skim or 1% milk rather than whole milk increased with nutrition knowledge, income, trying to reduce cholesterol intake, and being female (P < .05). Frequency of milk consumption was higher with nutrition knowledge, frequency of milk consumption during adolescence, and following a diabetic diet but was lower with milk intolerance. CONCLUSIONS: The present results could be used to develop intervention strategies for improving milk consumption rates among older adults. These strategies might focus on increasing elderly people's awareness of milk intolerance and lactose-reduced milk products and their concern about cholesterol. The relationship between current and adolescent milk consumption suggests that intervention strategies should begin early in life.     

Open extremity fracture penetrating the skull

We present a case in which an open fracture of the ulna penetrated the skull and caused a comminuted, depressed skull fracture with a large intraparenchymal hematoma containing bone fragments.     

Cost-effectiveness and pain medicine

The specialty of pain medicine, as noted by Lippe,“… justifies itself as a unique medical specialty by virtue of a distinct body of knowledge and a well-defined scope of practice. In common with other medical specialties, it is founded on an infrastructure of scientific research, education, and clinical practice [1].“ The traditional methods of education for healthcare providers, such as medical schools, nursing schools, physical therapy schools, and clinical psychology programs, do not prepare their students adequately for the delivery of evaluation and treatment services to patients experiencing pain. Also apparent, as evidenced by the dearth of medical literature, is that the traditional methods of educating pain specialists do not adequately prepare students for an effective approach to the realities of healthcare economics in their respective fields.The result of a lack of significant education in the economics of pain medicine can be financially devastating to a new practitioner who is practicing “good” medicine yet not meeting the financial obligations incipient in the operation of a multidisciplinary pain center or even a solo practice. One important concept in the study of healthcare economics is the issue of cost-effectiveness [2].     

Is schizophrenia genetically transmitted?

Clinicians and researchers alike have questioned and studied the origin of schizophrenia for decades. Since the early 1900s, a genetic hypothesis has been suggested. This article reviews studies on a possible genetic cause of schizophrenia by use of various methods of comparison: twins, adoption, family history, family studies, and studies of biologic markers. Most researchers conclude that schizophrenia is likely caused by a genetic predisposition coupled with environmental influences.     

Desmoplastic malignant melanoma presenting with orbital involvement

Desmoplastic malignant melanoma (DMM) is a rare variant of spindle cell melanoma. We report a case of DMM of the forehead secondarily involving the orbit. The diagnosis was based on light microscopic features, including prominent peripheral cell nest formation and spindle cell fascicles in densely collagenous stroma. Immunohistochemical studies showed strong uniform staining for S100 antigen throughout the tumour. It was negative for HMB 45, smooth muscle actin, desmin, cytokeratins and Type IV collagen. Electron microscopy showed neither melanosomes nor myelin figures. The clinical and histological characteristics of desmoplastic malignant melanoma, and its differential diagnosis of malignant schwannoma, are discussed. DMM has a poor prognosis, since it tends to invade deeply, recur locally and metastasise readily.     

Uveal effusion syndrome

The history and clinical findings are presented of a patient who suffered from the uveal effusion syndrome over a 10-year period from 1956. The funduscopic appearance is illustrated both at the time of initial presentation and 36 years later. This condition typically affects healthy middle-aged men and causes recurrent, spontaneous, serous retinal and ciliochoroidal detachments, often resulting in significant visual impairment. Two separate hypotheses have been postulated to explain the pathogenesis of the uveal effusion syndrome, one relating to abnormally thickened sclera, the other to chronic bulbar hypotony. Both are discussed, as is the rationale behind the current management of this unusual condition.     

Autoregulation of beat frequency in respiratory ciliated cells. Demonstration by viscous loading

As opposed to the virtually constant load exerted by water on the cilia of ciliated protozoa, the hydrodynamic load on respiratory cilia can undergo broad variations because of changes in the rheologic properties of mucus. When water-rowing ciliated cells are exposed to increased viscosity (1 to 50 cP), their beat frequency decreases exponentially. According to Newton's fluid dynamic theory, this outcome is expected for an engine that generates constant force. However, the findings reported here indicate that when mucus-propelling respiratory ciliated cells are exposed to high viscous loads, ranging from 12 to 150 cP, the frequency of ciliary beat decreases only slightly, whereas the beat amplitude remains virtually constant. These observations suggest that ciliated cells of the respiratory tract have a functional reserve that allows them to autoregulate their mechanical output in response to the changes in viscosity to which they are normally exposed in the airway.     

Dietary fat intake and plasma lipid levels in adolescents.

The relationship between dietary fat intake and fasting plasma lipid levels was assessed in 35 female and 19 male adolescents recruited from two local education authority schools in Norwich, UK. Dietary intakes were assessed using a 7-day weighed dietary record method, coupled with the collection of duplicate diets. Fat and energy intakes calculated using food composition tables were compared with values obtained by direct analysis of duplicate diets. Fasting plasma lipid levels (total, HDL and LDL cholesterol and triglycerides) were measured and compared with total dietary lipids and fatty acid intakes. The average proportion of energy consumed as fat was higher than is currently considered desirable but lower than previous studies have reported for adults. Mean serum total cholesterol values were 4.2 (SEM 0.1) mmol for females and 4.5 (SEM 0.2) mmol for males; this difference was not statistically significant. In male subjects the dietary fatty acid profiles were significantly correlated with several parameters of plasma lipid status which are thought to be risk factors for coronary heart disease, and in particular with the ratio of total:HDL cholesterol.