Assessment of borderzone ischemia with a combined MR imaging-MR angiography-MR spectroscopy protocol

We attempted to assess whether magnetic resonance imaging (MRI)-MR angiography (MRA)-MR spectroscopy (MRS) measurements can be used in the differentiation of patients in whom severe carotid lesions result in chronically hypoperfused regions and in whom the collateral capacity is sufficient to maintain a normal cerebral blood flow. Sixty-six patients with severe stenosis of the internal carotid artery (ICA) and 19 control subjects underwent MRI, 1H MRS, and MRA. Anaerobic metabolic changes in the middle cerebral artery (MCA) territory were studied by assessing N-acetyl-L-aspartate (NAA)/choline and lactate/ NAA ratios. Quantitative flow was measured in the ICA, in the basilar artery, and in the MCA. Thirty-four patients had borderzone infarcts, 16 patients had territory infarcts, and 16 patients had no infarcts on MRI. Patients with border-zone infarcts had significantly reduced flow in the ICA (P < 0.001) and in the MCA (P < 0.05) and decreased NAA/ choline ratios (P < 0.001) in non-infarcted regions compared with control subjects (P < 0.001) but also compared with patients with territory infarcts (P < 0.05) and patients without infarcts (P < 0.05). Flow measurements in the ICA and MCA and metabolic measurements in the MCA territory can be applied to select patients in whom cerebral perfusion pressure is insufficient to maintain normal cellular integrity.     

Informal caregiving for frail older people at home and in long-term care institutions: who are the key supporters?

This paper describes the extent of the informal caregiving unit for older people who are physically or mentally frail living in private households or resident in long-term care institutions using cross-sectional analysis of survey data. A total of 1444 people aged 65 years or more registered with a general practitioner (GP) in four areas in England and, consenting to the study, were screened for mental or physical frailty. Of 1127 older subjects living at home 7% reported receiving no informal support, 15% had a paid supporter only and 78% nominated a key informal supporter who helped with defined activities of daily living of whom 650 (74%) were interviewed. Only 13% nominated more than one informal supporter. Key supporters were spouses (38%), daughters (30%), sons (9%), daughters-in-law (4%), other relatives (11%) and friends and neighbours (8%). Of 317 frail older people resident in long-term care institutions 175 (55%) received a main visitor at least once a week of whom 132 (75%) were interviewed. Main visitors were spouses (11%), daughters (36%), sons (23%), daughters-in-law (2%), other relatives (24%) and friends (4%). Qureshi & Walker's (1989) hierarchical, decision-making model for selecting informal caregivers was applied to the data and correctly identified 85% of key informal supporters and 79% of main visitors interviewed. This large-scale comprehensive survey of informal care for frail older people supports earlier small-scale localized studies highlighting the key role of spouses and daughters in the provision of informal support. Families of frail older people provide the support to maintain people at home.     

Improvement of brain single photon emission tomography (SPET) using transmission data acquisition in a four-head SPET scanner

Attenuation coefficient maps (-maps) are a useful way to compensate for non-uniform attenuation when performing single photon emission tomography (SPET). A new method was developed to record single photon transmission data and a-map for the brain was produced using a four-head SPET scanner. Transmission data were acquired by a gamma camera opposite to a flood radioactive source attached to one of four gamma cameras in the four-head SPET scanner. Attenuation correction was performed using the iterative expectation maximization algorithm and the-map. Phantom studies demonstrated that this method could reconstruct the distribution of radioactivity more accurately than conventional methods, even for a severely non-uniform-map, and could improve the quality of SPET images. Clinical application to technetium-99m hexamethylpropylene amine oxime (HMPAO) brain SPET also demonstrated the usefulness of this method. Thus, this method appears to be promising for improvement in the image quality and quantitative accuracy of brain SPET.This work was presented in part at the World Congress on Medical Physics and Biomedical Engineering, 7–12 July 1991, Kyoto, Japan     

Differential motion hyperacuity under conditions of common image motion

Sensitivity to horizontal shearing motion in random dots was measured as a function of common image motion amplitude. Without common image motion, thresholds for differential motion are comparable or better than vernier acuity. Above about 2 arc min of common image motion there is a proportionate increase in motion parallax thresholds such that for 20 arc min of common image motion, differential motion thresholds have risen by an order of magnitude. This differs from a comparable lack of threshold elevation for vernier acuity targets under similar conditions of movement (Westheimer and McKee, 1975). By varying movement duration, it can be shown that common image motion amplitude rather than common image velocity is the primary determinant of the effect. Furthermore this degradation of performance is not affected by changes in random dot size. Under favorable circumstances the phenomenon can also be seen with differentially moving vernier lines. The effect shows directional selectivity such that common motion directions closest to the horizontal leads to the greatest interference. The results add weight to the view that differential motion hyperacuity is mediated by a separate mechanism than differential position hyperacuity.     

Oxidative damage on DNA induced by asbestos and man-made fibers in vitro

Summary We compared the potential of asbestos and man-made fibers to attack DNA by the determination of the yield of 8-hydroxy-2-deoxyguanosine (8-OH-dGuo) under several in vitro conditions. Asbestos induced 6.6–99.8 of 8-OH-dGuo per 10⁵ dGuo in calf thymus DNA after 20 h of incubation, while the levels of 8-OH-dGuo in man-made fibers were low (3.6–9.4). The amounts of 8-OH-dGuo were strongly stimulated by the addition of H₂O₂ in asbestos, but not in man-made fibers. However, the yield of 8-OH-dGuo was induced more than that with asbestos by the further addition of FeSO₄ in attapulgite, fiberglass, potassium titanate whisker, and metaphosphate polymer. The addition of ethylene diamine tetraacetic acid (EDTA) promoted the induction of 8-OH-dGuo with asbestos and H₂O₂. The effects of mannitol (known as a hydroxy radical scavenger) were not dramatic on 8-OH-dGuo induction by all fibers except fiberglass and basic magnesium sulfate whisker, which induced higher amounts after mannitol addition than in these fibers and H₂O₂. Therefore, it was suggested that asbestos could damage DNA, resulting in 8-OH-dGuo as a cause of point mutation, and also several types of manmade fibers had similar effects to asbestos under certain conditions.     

New strategies in immunosuppression

This article reviews recent papers relating to immunosuppressives and attempts to categorise the bewildering number of new reagents according to their effects on the immune response. It is apparent that the majority of groups are concentrating on reagents which, like cyclosporin A, are predominantly directed at T cells (42% of the last 200 papers inTransplantation, Transplant International andTransplantation Proceedings). The major change in strategy which is occurring relates to the rapidly increasing use of reagents directed against T cell subsets, especially those directed against the interleukin-2 receptor and CD4-positive T cells. This groups's share of the market has risen from 2% to over 12% within 5 years. New successful monoclonal antibodies include reagents directed against antigen-presenting cells and against molecules directly involved in cell adherence. The use of donor bone marrow or subsets of cells from donor bone marrow as inducers of non-reactivity, especially to solid organ grafts, is certainly one of the most exciting of the non-antibody protocols. It is encouraging that relatively specific immunosuppression can be induced in animals by combinations of specific and non-specific reagents as well as by specific reagents alone. This will facilitate the introduction of specific protocols into the human situation, and this strategy holds out great hope for the future. Unfortunately, one of the most effective ingredients of such combination therapies in animal models (anti-CD4) appears to have its tolerogenic potential abrogated by cyclosporin A and FK-506. One area of immunosuppression which is receiving scant interest relates to antibody (especially non human leucocyte antigen antibody) production, but as the interest in xenotransplantation increases it is anticipated that major new interest will emerge in this area.     

Does Hyperthermia Induce Peritoneal Damage in Continuous Hyperthermic Peritoneal Perfusion?

To investigate the mechanisms of the peritoneal damage induced by continuous hyperthermic peritoneal perfusion (CHPP), protein and fluid loss during and after CHPP and continuous normothermic peritoneal perfusion (CNPP) was studied. Sixteen patients with advanced gastric cancer underwent peritoneal perfusion therapy with saline solution containing 150 to 300 mg cisplatin and 30 to 60 mg mitomycin C for 60 minutes. The temperature in Douglas' pouch was maintained at 42.0°C in the CHPP group (n= 9) and 37.0°C in the CNPP group (n= 7) during perfusion. No statistical differences were found in patients' characteristics between the groups except the maximum temperature in Douglas' pouch during perfusion (41.6°± 0.4°C and 37.6°± 0.4°C in CHPP and CNPP groups, respectively, p < 0.05). The amount of protein lost into the perfusate was 0.35 ± 0.22 g/kg body weight in the CHPP group and 0.37 ± 0.19 g/kg in the CNPP group, showing no significant difference. On the day of surgery, there was no significant difference in the amount of protein and fluid lost through the abdominal drains between the CHPP group (27.9 ± 24.6 mg/kg/hr and 0.94 ± 0.63 ml/kg/hr, respectively) and the CNPP group (25.9 ± 8.6 mg/kg/hr and 1.03 ± 0.31 ml/kg/hr, respectively). We could not find any significant differences in postoperative protein and fluid loss between the groups on the following 3 days either. We conclude that the peritoneal damage by CHPP is not caused by the hyperthermia but by the peritoneal perfusion with saline solution containing anticancer drugs.     

Genetic basis of neonatal methicillin-resistant Staphylococcus aureus in Japan

Methicillin-resistant Staphylococcus aureus (MRSA) is still one of major problems of drug-resistant microorganisms and healthcare-acquired infections. Methicillin-resistant Staphylococcus aureus is highly prevalent in patients in neonatal intensive care units (NICU) in Japan. The most predominant MRSA in NICU is multidrug resistant and produces superantigenic exotoxin, toxic shock syndrome toxin-1 (TSST-1) and staphylococcal enterotoxin C (SEC). These predominant MRSA strains belong to coagulase type II, SCCmec type II, mecA-Tn554 polymorph type I-A and show closely related pulse field gel electrophoresis types. The dissemination of MRSA is wide, and there is a pandemic distribution of a single MRSA clone in the NICU of Japan. Since 1992, the nationwide spread of this clone has also led to the development of a new neonatal disease known as neonatal toxic shock-like exanthematous disease (NTED), which is caused by overactivation of vbeta2+ T cells induced by TSST-1. The spread of MRSA in NICU in Japan has been attributed to overcrowding, high rates of extremely low birthweight babies, understaffing, low control measures of infection and overuse of antibiotics. The environment of NICU and infection control intervention should be improved and a new strategy for control like vaccination or probiotics is required.     

A case of female alcoholic who developed liver cirrhosis with small amounts of alcohol by the common use of contraceptive agent]

A case of female alcoholic who developed liver cirrhosis with small amounts of alcohol by the common use of contraceptive agent was reported. A case was a 33-year-old female who had complained of systemic edema and jaundice. She had been drinking alcohol, while she had been taking the contraceptive agent from 20-year-old. On admission, she had a large amount of ascites with jaundice. She was diagnosed as liver cirrhosis and hepatic failure by CT scanning of abdomen and laboratory data. Her condition was temporarily improved by the abstinence and the treatment. Since she drank under hospitalization, she had to change the hospital and died after 2 months. She had been drinking for only 10 years. Her cumulative alcohol intake was also very small. She may have developed alcoholic cirrhosis with small amount of alcohol because of common use of contraceptive agent with drinking.