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Biomedical subjects

J Marx

Publications and source records attributed to J Marx.

At least 37 records · Page 2Linked to original sources
PubMed2001

Time course of lesion development in patients with acute brain stem infarction and correlation with NIHSS score.

BACKGROUND AND PURPOSE: diffusion weighted magnetic resonance imaging (MRI) is highly sensitive in detecting acute supratentorial cerebral ischemia and Diffusion Weighted Imaging (DWI) lesion size has been shown to correlate strongly with the neurologic deficit in middle cerebral artery territory stroke. However, data concerning infratentorial strokes are rare. We examined the size and evolution of acute brain stem ischemic lesions and their relationship to neurological outcome. METHODS: brain stem infarctions of 11 patients were analyzed. We performed DWI in all patients and in 7/11 patients within 24 h, T2W sequences within the first 2 weeks (10/11 patients) and follow-up MRI (MR2) within 3-9 months (median 4.8 months) later (12/12 patients). Lesion volumes were compared with early and follow-up neurologic deficit as determined by National Institutes of Health Stroke Scale (NIHSS) score. RESULTS: the relative infarct volumes--with MR2 lesion size set to 100%--decreased over the time (P<0.02) with a mean shrinking factor of 3.3 between DWI (MR0) and the follow-up MRT (P<0.02), and 1.6 between early T2W (MR1) and MR2 (P<0.04). The mean DWI volume size (MR0) was larger than the early T2W (P<0.02). Although neurological outcome was good in all patients (mean NIHSS score of 1.3 at follow-up), early NIHSS and follow-up NIHSS scores were strongly correlated (r=0.9, P<0.00). NIHSS score at follow-up was highly correlated with lesion size of DWI (MR0; r=0.71, P<0.04) and T2W of MR1 (r=0.86, P<0.001). CONCLUSIONS: in this study, we saw a shrinking of the brain stem infarct volume according to clinical improvement of patients. Great extension of restricted diffusion in the acute stage does not necessarily implicate a large resulting infarction or a bad clinical outcome.

Brain Stem Infarctions↗
PubMed2001

Reduction of ultraviolet transmission through cotton T-shirt fabrics with low ultraviolet protection by various laundering methods and dyeing: clinical implications.

BACKGROUND: The public has long been instructed to wear protective clothing against ultraviolet (UV) damage. OBJECTIVE: Our purpose was to determine the UV protection factor (UPF) of two cotton fabrics used in the manufacture of summer T-shirts and to explore methods that could improve the UPF of these fabrics. METHODS: Each of the two types of white cotton fabrics (cotton T-shirt and mercerized cotton print cloth) used in this study was divided into 4 treatment groups: (1) water-only (machine washed with water), (2) detergent-only (washed with detergent), (3) detergent-UV absorber (washed with detergent and a UV absorber), and (4) dyes (dyed fabrics). Ultraviolet transmission through the fabrics was measured with a spectrophotometer before and after laundry and dyeing treatments. Based on UV transmission through these fabrics, the UPF values were calculated. RESULTS: Before any treatments, the mean UPFs were 4.94 for the T-shirt fabric and 3.13 for the print cloth. There was greater UVA (320-400 nm) than UVB (280-320 nm) transmission through these fabrics. After 5 washings with water alone and with detergent alone, UPF increased by 51% and 17%, respectively, for the cotton T-shirt fabric. Washing the T-shirt fabrics with detergent plus the UV-absorbing agent increased the UPF by 407% after 5 treatments. Dyeing the fabric blue or yellow increased the UPF by 544% and 212%, respectively. Similar changes in UPFs were observed for the print cloth fabric. CONCLUSION: The two cotton fabrics used in this study offered limited protection against UV radiation as determined by spectrophotometric analysis. Laundering with detergent and water improves UPF slightly by causing fabric shrinkage. Dyeing fabrics or adding a UV-absorbing agent during laundering substantially reduces UV transmission and increases UPF. More UVA is transmitted through the fabrics than UVB.

Coloring Agents↗
PubMed2001

The course of corticofacial projections in the human brainstem.

Transcranial magnetic stimulation was used to investigate the corticofacial projections in 53 patients with (n = 28) and without (n = 25) central facial paresis due to unifocal ischaemic lesions at different brainstem levels. Lesion topography documented by MRI studies was correlated with the electrophysiological findings. In the majority of patients the corticofacial fibres travel within the ventromedial base of the pons and cross the midline at the level of the facial nucleus. In some individuals, however, we found evidence that corticolingual fibres form an 'aberrant bundle' in a paralemniscal position at the dorsal edge of the pontine base. In other patients the corticofacial fibres loop down into the ventral part of the upper medulla, cross the midline and ascend in the dorsolateral medullary region ipsilaterally to the facial nucleus. The findings suggest that facial paresis due to a brainstem lesion may present as contralateral supranuclear facial paresis by a lesion of the cerebral peduncle, pontine base, the aberrant bundle and the ventral medulla. Supranuclear facial paresis ipsilateral to the lesion side may result from a lesion in the lateral medulla, and facial paresis of the supranuclear type may be imitated by a lesion of the peripheral facial nerve in the dorsolateral medulla with involvement of the lower pons.

Brain Stem↗
PubMed2001

Perceived outcomes of public health privatization: a national survey of local health department directors.

Almost three quarters of the nation's local health departments (LHDs) have privatized some services. About half of LHD directors who privatized services reported cost savings and half reported that privatization had facilitated their performance of the core public health functions. Expanded access to services was the most commonly reported positive outcome. Of those privatizing, over two-fifths of LHDs reported a resulting increase in time devoted to management. Yet, one-third of directors reported difficulty monitoring and controlling services that have been contracted out. Communicable disease services was cited most often as a service that should not be privatized. There is a pervasive concern that by contracting out services, health departments can lose the capacity to respond to disease outbreaks and other crises.

Administrative Personnel↗
PubMed2001

Privatization and the scope of public health: a national survey of local health department directors.

OBJECTIVES: This study sought to obtain and analyze nationally representative data on (1) privatization of local health department services, (2) local health department directors' beliefs and perspectives on the desirable role and focus of health departments, and (3) the influence of these views on privatization practices. METHODS: A stratified representative national sample of 380 local health department directors was drawn, and 347 directors were interviewed by telephone. Logistic regression established the independent effects of various factors on decisions to privatize. RESULTS: Almost three quarters (73%) of the local health departments privatized public health services of some type. The 12% of the directors who believed that local health departments should be restricted to the core public health functions and move entirely out of direct provision of personal health care were more likely to privatize services. The 77% of the directors who believed that local health departments should be involved in an increasing array of social problems were more likely to privatize. CONCLUSIONS: Privatization has quietly and quickly become commonplace in public health, and privatization practices are intimately related to divergent conceptions of public health and the role of local health departments.

Administrative Personnel↗
PubMed2001

Mechanisms and predictors of chronic facial pain in lateral medullary infarction.

The purpose of this study was to identify clinical predictors and anatomical structures involved in patients with pain after dorsolateral medullary infarction. Eight out of 12 patients (67%) developed poststroke pain within 12 days to 24 months after infarction. The pain occurred in the ipsilateral face (6 patients) and/or the contralateral limbs and trunk (5 patients, 3 of whom also had facial pain). Ipsilateral facial pain was significantly correlated with lower medullary lesions, including those of the spinal trigeminal tract and/or nucleus, as documented by magnetic resonance imaging. The R2 blink reflex component was abnormal only in patients with facial pain. Likewise, pain and temperature sensation in the ipsilateral face was decreased in all patients with facial pain but not in patients without pain. Ipsilateral touch sensation in the face was also decreased in all patients with facial pain, but the lesions revealed on magnetic resonance imaging did not involve the principal sensory nucleus of the fifth cranial nerve, and the R1 blink reflex latencies were normal. Although facial pain was correlated with lesions of the spinal trigeminal tract and/or nucleus, none of the lesions involved the subnucleus caudalis, which contains most nociceptive neurons. These findings suggest that facial pain after medullary infarction is due to lesions of the lower spinal trigeminal tract (axons of primary afferent neurons), leading to deafferentation of spinal trigeminal nucleus neurons.

Aged↗
PubMed2000

Molecular biology. Cancer fighter's modus operandi revealed.

Researchers have deciphered how a promising cancer drug acts like a smart bomb, homing in on only a very narrow range of its potential targets in the cell. The compound, known as STI-571, has shown remarkable success in early clinical trials on patients with chronic myelogenous leukemia. Now, in work reported on page 1938, scientists reveal just how the compound works--information that could aid in the design of similar cancer therapies.

Antineoplastic Agents↗
PubMed2000

Medicine. DNA arrays reveal cancer in its many forms.

The use of microarrays--slides or chips systematically dotted with DNA from thousands of genes--to determine gene expression patterns is providing a wealth of new information that should aid in cancer diagnosis and ultimately in therapy. In the past several months, researchers in several labs have used microarray technology to identify specific subtypes of a variety of cancers, including leukemias and lymphomas, the dangerous skin cancer melanoma, and breast cancer. In some cases, they can determine which cancers are likely to respond to current therapies and which aren't. In addition, the studies are giving researchers a fix on which genes are important for the development, maintenance, and spread of the various cancers, and are thus possible drug targets.

Disease Progression↗
PubMed2000

Tumor angiogenesis. Gene expression patterns identified.

Researchers have obtained the most detailed sketch yet of how cancerous tumors secure the blood supplies that nourish their growth. On page 1197, a team reports the results of a large-scale comparison of the genes expressed in the blood vessels of human colon cancers and of normal colon tissue. They've found that the gene expression patterns of the two types of vasculature are distinctly different. The findings could help researchers develop new anticancer drugs that work by homing in on the protein products of genes that are overexpressed in tumor vessels, thus shutting off the growth of blood vessels the tumor needs to survive.

Angiogenesis Inhibitors↗
PubMed2000

Masseter reflex latencies and amplitudes are not influenced by supratentorial and cerebellar lesions.

The aim of this study was to investigate possible influences of suprasegmental lesions on the masseter reflex. The masseter reflex was elicited in 54 patients with supratentorial (37 patients) or cerebellar (17 patients) lesions 3-11 days after the acute onset of clinical disease. Patients showing lesions within the pons and midbrain on thin-slice magnetic resonance imaging were excluded from evaluation. The testing procedure included an additional facilitating maneuver (opening and closing the jaw before tapping). Masseter reflex latencies, interside differences, and amplitudes were within the normal range in all patients. Latencies were not different with and without the facilitating maneuver. Amplitudes were significantly higher with the maneuver, but interside differences of amplitudes were unchanged. Masseter reflex abnormality can be taken as a reliable measure of direct involvement of the reflex arc.

Adult↗