Sinonasal undifferentiated carcinoma: CT and MR imaging of an uncommon neoplasm of the nasal cavity

C1 domains are compact alpha/beta structural units of about 50 amino acids which tightly bind two zinc ions. These domains were first discovered as the loci of phorbol ester and diacylglycerol binding to conventional protein kinase C isozymes, which contain 2 C1 domains (C1A and C1B) in their N-terminal regulatory regions. We present a comprehensive list of 54 C1 domains occurring singly or doubly in 34 different proteins. Many C1 domains and C1 domain-containing proteins bind phorbol esters, but many others do not. By combining analysis of 54 C1 domain sequences with information from previously reported solution and crystal structure determinations and site-directed mutagenesis, profiles are derived and used to classify C1 domains. Twenty-six C1 domains fit the profile for phorbol-ester binding and are termed "typical." Twenty-eight other domains fit the profile for the overall C1 domain fold but do not fit the profile for phorbol ester binding, and are termed "atypical." Proteins containing typical C1 domains are predicted to be regulated by diacylglycerol, whereas those containing only atypical domains are not.     

Clinical informatics and the dental curriculum. A review of the impact of informatics in dental care, its implications for dental education

Important advances have been made in the field of supraventricular and ventricular tachycardias. Catheter ablation procedures are potentially curative in many patients suffering of supraventricular tachycardias. The technique uses radiofrequency current. This form of energy is already very familiar to surgeons. Expected benefits as well as potential complications have to be discussed with the patient prior to the ablation procedure. The automatic internal defibrillator has been commercially available since the end of the eighties. It delivers electrical therapy in case of ventricular malignant arrhythmias, for instance ventricular fibrillation. The sudden death rate is markedly reduced in implanted patients. The long term prognosis however remains critically dependent of the left ventricular function and possible progressive heart failure. Reimbursement depends on pre-implant agreement by the Social Security. At the present time, no reimbursement is provided for prophylactic indications. These two techniques facilitates the treatment of patients previously described as "resistant cases".     

Impact of the Delaney Clause in the EPA

The U.S. Environmental Protection Agency serves as the lead agency of the Federal government for the regulation of pesticide use in the United States. Regulatory responsibilities are mandated in the Federal Insecticide Fungicide and Rodenticide Act (FIFRA) and several sections of the Federal Food Drug and Cosmetic Act (FFDCA). In order for a pesticide to be used in the U.S., it must either be granted a full registration under Section 3, or offered special consideration under Section 18 or 24 of FIFRA. Tolerances (maximum allowable residue limits) for pesticides to be used on agricultural commodities meant for human consumption or animal feed are established under Sections 408 and/or 409 of FFDCA. This presentation will describe the underlying conflict between Section 409 of FFDCA and both Section 408 and FIFRA, the recommendations made by the National Academy of Sciences in its 1987 publication Regulating Pesticides in Food--The Delaney Paradox, EPA's attempts to implement these recommendations, the true impact of "Delaney" on the ability of EPA to grant tolerances on raw or processed foods for chemicals determined to meet the "induce cancer" criterion and the status of legislation designed to "fix" Delaney.     

Acetogenic coccoid spore-forming bacteria isolated from the rumen

Thirteen strains of a new acetogenic bacterium were isolated from the rumen contents of lambs, llamas and bisons. This paper is the first report of Gram-positive coccoid spore-forming bacteria occurring in chains and able to use H2 + CO2 as energy source and produce acetate from this gas mixture. One of them, chosen as the reference strain for its efficiency in utilizing H2/CO2 likely via the acetyl-CoA pathway, was characterized in detail. The G + C ratio of the DNA of the organism was 46.5 mol%. The temperature and pH optimum were 37 degrees-40 degrees C and 6.3-6.8, respectively. Numerous organic substrates including some o-methylate aromatic compounds were used heterotrophically. The full 16S rRNA gene sequence was determined. The phylogeny, physiology, morphology and numerous features described here are sufficiently different from those of any bacteria described today to justify the definition of a new species. The name "New acetogenic bacterium" is temporarily proposed, awaiting a future taxonomic revision of the genus Clostridium.     

The role of arterial hypertension in the occurrence of strokes at a young age

The analysis of insult occurrence in patients at the age under 45 years, caused by blood hypertension, shows, that they make 30.1% from common number of insult in 166 young people, treated in the neurological and other departments of Burdenko Main Military Clinical Hospital in 1989-1996. On occasion of ischemic insult were treated 37 patients, hemorrhagic--13. The reason of insults was "soft" blood hypertension: in 51.4%--at ischemic insult and in 30.1%--hemorrhagic. The authors consider, that the main direction of prophylaxis of insult is active revealing and adequate treatment of the patients with blood, including "soft" hypertension, use of hypotensive preparations and some non-medicative methods of treatment.     

The role of the Cell Saver autologous transfusion method in preventing the pulmonary distress syndrome during open-heart operations on children

Complex estimation of the state of the lungs at the postperfusion and early postoperative periods based on roentgenological, clinical data, investigations of the parameters of oxygenation and mechanics of respiration was carried out in 32 children with septal defects of the heart, operated upon under conditions of artificial blood circulation with different kinds of the transfusion maintenance including the apparatus "Cell Saver 5" (CS) for the reinfusion of autoerythrocytes. The dynamics of endotoxicosis, hematological parameters during and after operation and requirements in transfusion media were studied. Differences in these indicators were established between the patients operated upon with the use of donor hemocomponents and those who were operated upon with CS. It allowed a conclusion about the role of the method of intraoperative reinfusion of erythrocytes in substantially less frequency and severity of the postperfusional pulmonary complications in this category of patients.     

Distinct immunological states in murine cutaneous leishmaniasis by immunising with different amounts of antigen: the generation of beneficial, potentially harmful, harmful and potentially extremely harmful states

Infection of BALB/c mice with a standard and substantial number of Leishmania major parasites results in progressive disease, following the induction of a parasite-specific Th2 response. These mice have been designated as "susceptible" on this basis. We show that distinct types of immune response can be generated in "susceptible" BALB/c mice depending upon the number of parasites employed for infection, and that the pathophysiological consequences of such distinct responses are dramatically different. Infection with very low numbers of parasites results in the exclusive induction of a cell-mediated, Th1 response, and the generation of resistance to the standard and substantial challenge. Spleen cells from such resistant mice can confer resistance upon normal mice when transferred to them, but these spleen cells do not contain T cells expressing DTH or Th1 effector cells that produce IFN gamma on short term culture (48 hrs) with parasite antigen. The immune response in this case appears to result in the virtual elimination of parasites from the lymph node draining the site of infection and, by implication, from the infected mouse. We suggest that such elimination results in the absence of antigen stimulation and hence of effector T cells, and that "memory Th1 cells" are responsible for the capacity of spleen cells to confer resistance on normal mice. We predict such mice will not suffer parasitemia upon immune suppression, i.e. are not susceptible to reactivation disease. This is the "beneficial state". In contrast to this infection with a very low number of parasites infection with a low number usually results in one of two states: (i) The generation of a response with a very small Th2 component, production of a small amount of antibody, chronic parasitemia and hence chronic generation of parasite-specific effector Th1/Th2 cells, or (ii) The generation of a response with a greater Th2 component, the production of more antibody, the formation of a frank lesion, and the long term generation of a stable, mixed Th1/Th2 response. We refer to the latter state as borderline leishmaniasis in analogy with borderline leprosy. Parasites can be recovered from the draining lymph node in both these cases many months after infection. We therefore believe that mice infected with a low number of parasites, that harbour a chronic subclinical infection, will suffer reactivation disease upon immune suppression, and we consequently designate the state generated as potentially harmful. We consider mice with borderline disease to be in a harmful state. Mice immunised with high doses of parasite antigen produce in the long term Th2 responses, whereas those immunised with lower doses produce Th1 responses. Mice immunised to produce a Th2 response were subsequently infected with a very low number of parasites that is normally contained. The generation of a Th2 response results in the generation of a Th2 imprint, such that the response to the low dose infection is modulated from a Th1 to a Th2 mode, resulting in progressive disease. We argue that immunisation/vaccination, resulting in a state that deviates the protective response to a non-protective mode, may result in epidemics. Such a state has the potential for being extremely harmful.     

In support of the telomere concept

The frequency of recovered X-ray-induced (4000R) rearrangements that, in all probability mimic terminal deletions of the X chromosome was only one of, roughly, 10-5 X chromosomes screened for tip deficiencies. Although the single exception looks terminally deleted, it is probably capped by a very short or nonpolytene telomeric segment. It is apparent from these data that the probability of "healing" or stabilization of a terminally deleted X in the zygotic nucleus or developing embryo of Drosophila melanogaster is vanishingly small. The telomeric caps in two obviously interstitial deficiencies that were recovered represent, roughly, 1/500 of the length of a mitotic chromosome. These findings give some indication of the extreme difficulty of detecting short telomeric segments capping either deleted polytene chromosomes or deleted metaphase chromosomes of, for example, humans.     

Operative creation of left to right cardiac shunts: pulmonary functional sequelae

The tuberomammillary nucleus, a cluster of cells in the posterior hypothalamus, is the only known source of brain histamine. Although this nucleus is well described in terms of anatomy and neurochemistry, only little is known about its function. In the present study, the effect of a lesion in the region of this nucleus on intracranial self-stimulation was examined. Rats were implanted bilaterally with stimulating electrodes in the lateral hypothalamus and unilaterally with one lesion electrode in the region of this nucleus. After three days of baseline testing, half of the animals were given an electrolytic lesion. The animals were retested for six consecutive days, and thereafter weekly for another seven weeks. From the second day postlesion on, we unexpectedly found a gradual increase in response rate, which peaked on day 13 in the ipsilateral hemisphere only. Although there was no further increase over subsequent days, response rates remained elevated during the following seven weekly tests. The observed increase in lateral hypothalamic self-stimulation after an electrolytic lesion of the tuberomammillary nucleus is discussed in terms of an inhibitory system, possibly located in the region of this nucleus which, when removed by the lesion, increased reinforcing effects of the electrical brain stimulation. The fact that the effects on self-stimulation were lateralized to one hemisphere rules out an interpretation in terms of unspecific "performance" variables that could influence rate of lever pressing.