Abstract: The effect of salivarectomy on feeding in Rhodnius prolixus was studied. Salivarectomized insects drew less blood and at a lower rate than controls when fed on a rabbit. Operated insects also pierced host skin much more often (10 times in 5 min) than controls (1 or 2 times in 5 min). None of these differences was observed when feeding was performed artificially through latex membranes. Intradermal injection of salivary secretion in rat tails increased the duration of bleeding induced by small cuts made on the injection site. It is suggested that the antihaemostatic action of saliva is important for positioning of the maxillae inside blood vessels.

Abstract: The salivary secretion ofRhodnius prolixus inhibits both ADP and collagen induced platelet aggregation in human platelet-rich plasma. Fractionation studies show that at least 3 different inhibitors are present inRhodnius saliva.

Abstract: Adult normal inbred mice rendered tolerant to OVA by previous oral exposure do not respond to intraperitonela immunization with DNP-OVA in adjuvant. These tolerant mice also form less DNP-specific antibodies to DNP-KLH when immunized with mixtures of DNP-KLH and DNP-OVA, or less HGG-specific antibodies when immunized with cross-linked conjugates of OVA and HGG. These same procedures increased DNP-specific or HGG-specific responses in non-tolerant control mice. The cross-supperssion was ineffective, however, to inhibit already ongoing antibody responses.

Abstract: 1 One hundred and eight patients were enrolled into an open long-term assessment of indoramin. All patients were initially treated with indoramin alone. After 6 weeks patients whose blood pressure was not satisfactorily controlled had a diuretic (hydrochlorothiazide) added. If after a further 4 weeks the blood pressure was still not controlled propranolol was added to indoramin and diuretic. 2 Twelve months' treatment were completed by 39 patients on indoramin alone, 32 on indoramin and diuretic and 29 on indoramin, diuretic and propranolol. All treatment groups reduced supine diastolic blood pressure to below 90 mm Hg. 3 Eight patients failed to complete treatment, three being withdrawn from treatment because of side-effects and five for non-treatment reasons. 4 The commonest side-effects were sedation, dry mouth, increase in appetite and failure of ejaculation. Three patients were withdrawn because of this effect but the other patients remained on treatment. All side-effects were reported in the early weeks of treatment, thereafter the effects appeared to tolerate out. 5 Sixty-nine patients on indoramin or indoramin and diuretic completed 2 years of treatment and 37 completed 3 years of treatment, the blood pressure being maintained below 90 mm Hg diastolic. A majority of patients were either maintained on the same dose or had the dose reduced.

Abstract: A two-parameter real-space renormalization-group approach to the site-percolation problem in a square lattice is proposed. The two parameters are the concentration $p$ of active first-neighbor bonds, and the concentration $q$ of occupied sites. From these two parameters one can calculate two independent critical exponents, and the others can be obtained through scaling relations, with no need of external applied fields.

Abstract: Pepstatin added to the blood meal of Rhodnius prolixus inhibited protein digestion in the midgut. This inhibition significantly reduced molting in all nymphal instars and retarded oogenesis in adults. Juvenile hormone analogue applied a day after feeding pepstatin did not promote oogenesis. Ecdysterone, however, applied after pepstatin potency had diminished 20 days after feeding, caused normal molting. These findings indicate that normal ecdysis and egg production in this hematophagous insect may depend on the availability of digested protein, as well as the presence of juvenile and molting hormone.

Abstract: Sao estudados seis pacientes, cinco do sexo feminino e um dos masculino, os quais, apos terem sofrido periodos variaveis de hipoxia cerebral provocada ou por parada cardio-respiratoria (cinco casos) ou por comprometimento pulmonar agudo, apresentaram alteracoes dos niveis de consciencia, que variaram de obnubilacao ao coma. Horas apos, tiveram crises convulsivas generalizadas do tipo tonico clonica. A medida que vieram recuperando a consciencia, desenvolveram abalos mioclonicos generalizados, de grande intensidade. Assim ficou caracterizada a encefalopatia mioclonica pos-anoxica que em homenagem aos autores que a descreveram, em 1963, e denominada tambem de sindrome de Lance-Adams. Cinco enfermos foram submetidos a exame eletrencefalografico, cujos tracados, em alguns, mostraram potenciais tipicos de mioclonias e, em outros, caracteristicas de comprometimento ceberal difuso por anoxia. Em um dos pacientes foi feito exame eletromiografico e em outros dois, tomografia cerebral por computador que revelou, em um deles, pronunciado alargamento das cisuras silvianas na base, especialmente a direita que justifica o quadro demencial apresentado por tal paciente. A analise bioquimica do liquido cefalorraquidiano feito em cinco casos, nao apresentou alteracoes.

Abstract: Analisa-se a incidencia de infeccoes hospitalares no Brasil e nos Estados Unidos, destacando-se a alta letalidade das mesmas em relacao a algumas doencas transmissiveis classicas. Explica-se a incidencia elevada em paises industrializados, nao obstante toda sofisticacao de instalacao e de equipamentos, distinguindo-se dois tipos basicos de doencas infecciosas. Admitindo-se que o desenvolvimento socio-economico promove uma reducao substancial nas doencas de origem exogena sem contudo impedir o aumento das doencas de origem endogena. Cita-se uma serie de evidencias que demonstram nao ter a equipe de saude substituido ainda os seus rituais magicos de profilaxia por medidas administrativas coerentes, derivadas do conhecimento cientifico produzido ao longo do tempo. Conclui-se que esse processo historico de racionalizacao sera, inevitavelmente, relutante e lento.

Abstract: Neste texto, procuro refletir sobre o percurso do estudo histórico que deve acompanhar a própria caminhada do pesquisador na "construção" do seu objeto de investigação. Somente essa reflexão filosófica metateórica propicia a formulação de perguntas e o encontro de respostas a respeito do valor das diferentes formas de seleção, percepção e apresentação dos fatos, assim como das várias interpretações possíveis, das possibilidades e dos limites do conhecimento, da verdade e da objetividade.

Abstract: The scattering of light in surfaces is of recent interest. The experimental techniques depend on a coherent and powerful radiation source such as a laser. Sergio Porto played a leading role in the development and use of laser sources in light scattering measurements, and this work is dedicated to his memory. The surface Brillouin spectra give information on the bulk excitations in the neighbourhood of the material boundary, and on surface excitations proper [1,2]. Light scattering in surfaces does not obey the wavevector selection rule familiar for scattering in transparent materials. Rather, the incident radiation couples to all the modes, which results in opacity Droadening. The theory of Brillouin scattering from the acoustic excitations in the surfaces of opaque materials involves the question of the momentum transferred from the radiation fields to the material when incident light (ωi, ki) is scattered into a measurable spectra (ωS, kS). The spectral peak is given in theory at a pseudo-momentum transfer of 2ηki for example in [1]. In another instance this is given by 2|n|ki in [3], where n = η + iμ is the complex refractive index which characterises the opaque material. These results are obtained from a rule of addition of wavevectors, sometimes complex [3]. The question of what the momentum transfer is when light scatters in surfaces of opaque materials needs to be answered, and takes us into a longstanding debate as to the momentum of light in a refracting medium [4–10].

Abstract: The cases of four patients with lymphoma with leucemic conversion, who exhibitted neoplasic infiltration of the central nervous system and of the meninges are reported. The anatomo-pathologic study showed the presence of small nodules of leucemic cells, in two patients. The other two patients had clinical improvement after the use of metotrexate by spinal route so that the anatomo-pathologic study of their CNS and meninges showed no abnomality.

Abstract: The physical consequences of the existence of inequivalent Lagrangians associated with a given equation of motion are examined in quantum mechanics. It is shown that in the case of conservative systems one additional condition is sufficient to select the physically correct Lagrangian. It is remarked that in the case of dissipative systems the situation is quite different, and no conditions are known to single out a unique Lagrangian.

Abstract: The ferroelectric transition of K4Fe (CN)6 3H2O is assumed to be associated with the ordering of the water molecules in the double-well potentials arising from their interactions with the ions of the structure. By applying the pseudo-spin formalism to this model we explain the independence of the transition temperature upon deuteration, and obtain for this temperature a value which is in good agreement with the experimental one. Our results support the hypothesis that potassium ferrocyanide trihydrate undergoes an order-disorder transition of the relaxational type.