Cortical activation by tactile and painful stimuli in hemispherectomized patients.

Hemispherectomized patients are able to perceive tactile and painful stimuli on their nonparetic as well as paretic body halves. We have used functional MRI to study the cortical mechanisms underlying this preserved somatosensory capacity. Nonpainful brushing and painful heat were applied to the skin of the legs in four hemispherectomized patients and, for comparison, in four normal subjects.

Effect of nonzero chain diameter on "DNA" condensation.

We present a simple model to investigate the effect of chain diameter on multivalent-counterion-induced attractions between two charged chains. In our minimal model, the chains are rigid rods of diameter D with a uniform charge density on the surface, and the counterions are point ions. As a function of the separation between two rods, we find a repulsive barrier in the free energy whose height increases with D.

The epidemiology of typhoid fever in the Dong Thap Province, Mekong Delta region of Vietnam.

A population-based surveillance for typhoid fever was conducted in three rural communes of Dong Thap Province in southern Vietnam (population 28,329) for a 12-month-period starting on December 4, 1995. Cases of typhoid fever were detected by obtaining blood for culture from residents with fever > or = 3 days. Among 658 blood cultures, 56 (8.

The short head of the biceps femoris as a monitor for the free lateral thigh flap in pharyngoesophageal reconstruction.

Free flaps are frequently used to reconstruct the defect following radical resection of pharyngoesophageal malignancy but postoperative monitoring of buried flaps is difficult. We have designed a monitoring-muscle flap using the short head of the biceps femoris muscle when using a free lateral thigh flap. The third and fourth perforators of the profunda femoris artery, the main vascular pedicle of the lateral thigh flap, pass through the short head of the biceps femoris.

Corticotropin releasing factor induces proliferation of cerebellar astrocytes.

In the adult cerebellum, corticotropin releasing factor (CRF), that is localized in climbing fibers, mossy fibers, and a fine varicose plexus along the Purkinje cell layer, modulates the responsiveness of Purkinje cells to excitatory amino acids. During development, CRF has been detected in the primitive cerebellar anlage as early as embryonic day (E)10, and is continuously expressed throughout embryonic and postnatal cerebellar ontogeny. To investigate a possible trophic role for CRF during cerebellar development, cerebellar culture studies using E18 mouse embryos were carried out.

Activation of Akt is induced by heat shock and involved in suppression of heat-shock-induced apoptosis of NIH3T3 cells.

Heat shock exposure to NIH3T3 cells for 15 min at 45 degrees C activated Akt, which is mediated by PI3-kinase, as evidenced by the significant inhibition of heat-shock-induced phosphorylation by specific inhibitors of PI3-kinase. The phosphorylated Akt was gradually decreased to the basal level within 9 h after heat shock. This resulted in growth arrest, but cell growth could be recovered within 24 h accompanied with a high rate of proliferation.

Localization of gp130 in the developing and adult mouse cerebellum.

Interleukin-6 (IL-6) type cytokines show functional redundancy in the immune, hematopoietic, and nervous system, which is believed to result from sharing of the signal transducing receptor gp130. IL-6 type cytokines and their binding receptors have been localized in the adult cerebellum. However, the cellular localization and developmental regulation of gp130 in the cerebellum have not been determined.

Pain perception: is there a role for primary somatosensory cortex?

Anatomical, physiological, and lesion data implicate multiple cortical regions in the complex experience of pain. These regions include primary and secondary somatosensory cortices, anterior cingulate cortex, insular cortex, and regions of the frontal cortex. Nevertheless, the role of different cortical areas in pain processing is controversial, particularly that of primary somatosensory cortex (S1).

Head and neck reconstruction using lateral thigh free flap: flap design.

Eleven lateral thigh free flaps were used in head and neck reconstruction, transferred on the basis of the second perforator as well as the third perforator of the profunda femoris artery. The lateral thigh free flap was useful and reliable in head and neck reconstruction and was versatile in flap design. Due to the wide cutaneous territory of the lateral thigh flap, the skin island could be designed freely in the lateral thigh region.

Diastolic shape of the right ventricle of the heart.

Background: Knowledge of right ventricular (RV) shape is important to the understanding of RV mechanical function and for the improvement of clinically important RV volume estimation techniques. Refinements to the simplest conceptions of RV shape are presented statistically here, based on a quantitative analysis of three-dimensional magnetic resonance (MR) images of excised lamb hearts.

Methods: The passive shape of the heart in six freshly excised lamb hearts was studied with MR imaging with independent passive pressurization of both ventricles.

Analysis of high-energy phosphometabolites in delayed experimental skin flaps using 31P nuclear magnetic resonance spectroscopy.

Using 31phosphorus magnetic resonance spectroscopy (31P-MRS) and surface coils, we noninvasively assessed the intracellular changes in delayed skin flaps of the high-energy phosphometabolites, ATP and phosphocreatine, which are basic energy sources of living cells. In 5 rats, a 3.5 x 7.

Differential localization of three distinct binding sites for sigma receptor ligands in rat spleen.

In vitro receptor autoradiography was used to localize sigma 1 receptors, sigma 2 receptors, and novel haloperidol/DTG-inaccessible sites for sigma and opiate ligands in rat spleen. Sigma-1 receptors were present throughout the spleen, but were most concentrated in the T cell zones. Binding under "sigma 2 receptor-selective' conditions was 70% nonspecific, and sigma 2 receptors could not be detected.

Initial characterization and autoradiographic localization of a novel sigma/opioid binding site in immune tissues.

High concentrations of novel, haloperidol- and DTG-inaccessible (+)-[3H]-3-PPP binding sites were found in human peripheral blood leukocytes rat spleen and splenocytes, but not in rat brain. Splenic sites were localized in a course punctate pattern in the marginal zones and red pulp. The pharmacology of the splenic sites was: (-)-SKF 10,047 > or = naltrexone = (-)-pentazocine > (+)-pentazocine = (-)-3-PPP = (+)-SKF 10,047 > or = (+)-3-PPP > or = dextrorphan > dextromethorphan > PCP > clorgyline.

Pulmonary blood flow profiles with reduced right ventricular function in lambs.

The determinants of right ventricular (RV) performance with damaged RV free wall, such as occurs with RV infarction, are still unclear. Using 20-MHz Doppler ultrasound equipment, we investigated the changes in pulmonary blood flow velocity profiles before and after ligation of the right coronary artery. RV dp/dt, stroke volume, RV stroke work, aortic pressure and cardiac output decreased and central venous pressure rose after the ligation.

Hemodynamics of the Fontan connection: an in-vitro study.

The Fontan operation is one in which the right heart is bypassed leaving the left ventricle to drive the blood through both the capillaries and the lungs, making it important to design an operation which is hemodynamically efficient. The object here was to relate the pressure in Fontan connections to its geometry with the aim of increasing the hemodynamically efficiency. From CT or magnetic resonance images, glass models were made of realistic atrio-pulmonary (AP) and cavo-pulmonary (CP) connections in which the right atrium and/or ventricle are bypassed.

The importance of accurate repair of the orbicularis oris muscle in the correction of unilateral cleft lip.

Most of the attempts and efforts in cleft lip repair have been directed toward the skin incision. The importance of the orbicularis oris muscle repair has been emphasized in recent years. The well-designed skin incision with simple repair of the orbicularis oris muscle has produced a considerable improvement in the appearance of the upper lip; however, the repaired upper lip seems to change its shape abnormally in motion and has a tendency to be distorted with age if the orbicularis oris muscle is not repaired precisely and accurately.

Blood flow velocity profiles in pulmonary branch arteries in lambs.

We studied the detailed profiles of blood flow in the right and left pulmonary arteries using 20 MHz pulsed Doppler ultrasound equipment in a lamb model. Fourteen lambs aged four to six weeks were selected. In six lambs, monocrotaline pyrrole was injected parenterally to create pulmonary hypertension (PH group).

Effects of chronically elevated pulmonary arterial pressure and flow on right ventricular afterload.

The effects of pulsatile hemodynamics on right ventricle-pulmonary circulation interactions were studied in control lambs and in two lamb models of altered pulmonary hemodynamics induced at infancy: elevated pulmonary arterial pressure (PAP) was created by the infusion of monocrotaline pyrrole (MCTP), and elevated pulmonary arterial blood flow was obtained by the creation of an arteriovenous fistula (Shunt). High-fidelity PAP, midvessel Doppler blood velocity (PAV), and cardiac output (CO) were measured in open-chest, anesthetized lambs. PAV waveforms were normalized to match the measured CO.

Parallel modified signed-digit arithmetic using an optoelectronic shared content-addressable-memory processor.

Addition is the most primitive arithmetic operation in digital computation. Other arithmetic operations such as subtraction, multiplication, and division can all be performed by addition together with some logic operations. With the binary number system, addition speed is inevitably limited by the carry-propagation schemes.

Reflective optical ring-array interconnects: an optical system design study.

We present a reflective optical ring-array interconnect architecture for handling data routings under various single-instruction-multiple-data array processing environments. The proposed architecture can perform clock-skew-free optical data communications for either a fixed-degree model, such as a nearest-neighbor network, or a variable-degree model, such as a plus-minus-2(i) network. It is found that space-variant routings, which are difficult to perform in a rectangular-array opto-electronic integrated circuit, can easily be mapped into rotation-invariant routines for optical implementation by a ring opto-electronic integrated-circuit array.

Induction of right ventricular hypertrophy with obstructing balloon catheter. Nonsurgical ventricular preparation for the arterial switch operation in simple transposition.

Background: Recently, a successful result with a rapid two-stage arterial switch operation (ASO) was reported for patients with transposition of the great arteries (TGA) with low left ventricular pressure. In this procedure, the interval between pulmonary arterial banding and ASO was approximately 1 week. This successful result indicates the possibility of a nonsurgical ventricular preparation procedure using an obstructing balloon catheter prior to ASO.

The effects of curvature on fluid flow fields in pulmonary artery models: flow visualization studies.

In vitro pulsatile flow visualization studies were conducted to assess the effects of varying radii of curvature of the right ventricular outflow tract (RVOT) and main pulmonary artery (MPA) on the flow fields in the main, right, and left pulmonary arteries of a one month lamb pulmonary artery model. Three glass flow-through models were studied; one with no curvature, one with the correct anatomic curvature, and one with an overaccentuated curvature on the RVOT and MPA. All other geometric parameters were held constant.