Computationally efficient algorithms for control of ultrasound phased-array hyperthermia applicators based on a pseudoinverse method

Computationally efficient incremental algorithms for application of the pseudoinverse method for ultrasound phased-array field pattern synthesis are discussed and shown to significantly reduce computing effort when more control points should be added to existing subsets of points previously manipulated. These algorithms avoid calculation of inverse matrices, a time-consuming job for microcomputers when the dimensions of the matrices are large. This technique can be used to recursively modify the heating patterns of a phased-array hyperthermia applicator in the clinic.

Detection of early pregnancy factor-like activity in human amniotic fluid

Early pregnancy factor (EPF), an immunosuppressive substance, appears in mammalian maternal serum at a very early stage after fertilization. To investigate the normal distribution of EPF in the human body, the rosette inhibition test has been used to detect EPF in human amniotic fluid. The mean value of rosette inhibition titer (RIT) was significantly higher (5.93 +/- 0.43 SE) in 52 amniotic fluid samples (16-30 weeks' gestation) than in 23 nonpregnant sera (3.54 +/- 0.11), indicating that something in amniotic fluid inhibits rosette formation. This inhibitory factor is recognized as EPF or EPF-like substance for its activity significantly correlated with that of EPF in serum from the same donor (r = 0.756: P less than 10(-6]. The immunological significance of the EPF-like substance in amniotic fluid may be important to the survival of semiallogeneic conceptus.

Effect of vagotomy on brain and plasma atrial natriuretic peptide during hemorrhage

These experiments investigated the change in brain, atrial, and plasma concentrations of atrial natriuretic polypeptide (ANP) after a 33% hemorrhage and the role of vagal nerve input in these changes. In rats, hemorrhage decreased plasma ANP from 246 +/- 48 to 41 +/- 7 pg/ml, but in a hypothalamic tissue block ANP increased from 19.0 +/- 0.9 to 25.5 +/- 0.6 ng/g tissue (P less than 0.05). Bilateral vagotomy was followed by a very large increase in plasma ANP to 703 +/- 198 pg/ml. Atrial pressures, however, fell after vagotomy from 2 +/- 2 to 1 +/- 1 mmHg. Therefore, the effect was not due to increased atrial stretch. Right atrial ANP levels were also elevated by vagotomy, but left atrial ANP concentrations did not change with vagotomy or hemorrhage. After hemorrhage in vagotomized rats, plasma ANP decreased to 79 +/- 6 pg/ml. After vagotomy, the ANP concentration in the hypothalamic block did not rise in response to hemorrhage. The results indicate that the vagus nerves provide a tonic inhibition of ANP levels in atria and plasma. The results cannot be explained by atrial distension. The results show independence of brain and plasma ANP and uncover a tonic vagal inhibition of ANP release.

High-resolution nonlinear laser spectroscopy of room-temperature GaAs quantum-well structures: observation of interference effects

We describe frequency-domain four-wave mixing spectroscopy measurements near the fundamental band edge in room-temperature GaAs multiple quantum wells. The line-shape information gives a measure of the dynamical behavior of the material and what is to our knowledge the first observation of an interference line shape due to a dominant slow contribution to the nonlinear response.

Lumbar myelography with iohexol in outpatients: prospective multicenter evaluation of safety

A multicenter open, noncomparative evaluation of the safety of iohexol was prospectively conducted in 81 adult outpatients undergoing screen-film lumbar myelography. Iohexol (180 milligrams of iodine per milliliter) was administered via a lumbar route at a dose of 8-17 mL. Computed tomography (CT) was performed after myelography. The safety of iohexol was assessed by monitoring adverse reactions and neurologic status and by measuring vital signs and serum laboratory values. The most frequent adverse reaction was headache (16 of 81 patients [19.7%]). Twelve patients complained of a headache on the day of the myelographic procedure, and four patients reported a headache 24 hours after the procedure. Nausea or vomiting occurred in four of 81 patients (4.9%) only on the day myelography was performed. No other neurologic abnormalities were found. Iohexol produced myelographic and CT studies of good to excellent quality in all patients. This study indicates that iohexol can be employed safely in lumbar myelography of adult outpatients.

Compression syndromes due to hypertrophic nerve roots in hereditary motor sensory neuropathy type I

Three patients with hereditary motor sensory neuropathy type I developed neurologic deficits attributable to hypertrophic nerve roots. Compression of the cervical spinal cord by enlarged nerve roots occurred in our index patient. Multilevel decompressive laminectomies relieved the myelopathy. An unrelated patient who had syncope precipitated by neck rotation had hypertrophied nerve roots that eroded into the transverse foramina in juxtaposition to the vertebral arteries. In a 3rd patient, compression of hypertrophied nerve roots within the thecal sac and neural foramina was associated with spinal claudication and radiculopathy, respectively.

Site-directed anti-peptide antibodies define the topography of the beta-adrenergic receptor

Molecular cloning has revealed the primary structure of a number of G-protein-linked receptors. The organization and topography of these proteins predicted to have seven hydrophobic membrane-spanning domains, in contrast, have not been established. Antibodies were prepared against 11 peptides corresponding to each of the hydrophilic sequences of the hamster beta 2-adrenergic receptor. Each of the anti-peptide antibodies displayed immunoreactivity for its synthetic peptide antigen and beta 2-adrenergic receptor (Mr 65,000) on blots of cell membranes and of purified receptor. All but three anti-peptide antisera also displayed immunoreactivity toward human placental and rat fat cell beta 1-adrenergic receptors, reflecting the level of sequence identity that exists between the two subtypes, Chinese hamster ovary cells stably transfected with an expression vector harboring the cDNA encoding the hamster beta 2-adrenergic receptor provided a cell type with 2 million receptors/cell, suitable for in situ localization of the sequences used as antigens. Indirect immunofluorescence of intact and permeabilized cells performed with these site-directed anti-peptide antibodies permitted the assignment of the general topography of each of the hydrophilic sequences of this G-protein-linked receptor. The results support the predictive value of hydropathy analysis for one class of membrane proteins with multiple transmembrane-spanning domains.

Effect of lipopolysaccharide on intestinal intramucosal hydrogen ion concentration in pigs: evidence of gut ischemia in a normodynamic model of septic shock

We tested the hypothesis that lipopolysaccharide (LPS) leads to an imbalance between mesenteric oxygen delivery (DO2) and gut metabolic demand for oxygen, even when cardiac index (CI) is within the normal range. Two groups of pentobarbital-anesthetized pigs (13 to 17 kg) were studied. The first group (LPS; n = 9) was infused over 20 min with Escherichia coli LPS (100 micrograms/kg) and resuscitated with normal saline (1.2 ml/kg.min). The second group (NS; n = 5) was not infused with LPS, but was resuscitated in the same way as the LPS group. Superior mesenteric arterial (SMA) blood flow and ileal intramucosal hydrogen ion concentration, [H+], were determined using a Doppler-shift probe and a tonometric catheter, respectively. Infusing LPS did not affect CI, although mean arterial pressure and systemic vascular resistance were significantly reduced. SMA flow and mesenteric DO2 decreased significantly in the LPS group. Although mesenteric oxygen utilization was well preserved in both groups, ileal intramucosal [H+] was significantly higher in endotoxic animals. These data support the idea that mesenteric oxygen consumption is flow-limited in this clinically relevant porcine model of septic shock.

Pulse, a PC-based graphics pulse sequence editor for NMR and MRI

A flexible, personal computer (PC) based, screen-graphics oriented pulse sequence editor called PULSE has been developed for nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI). PULSE is used to set such NMR spectroscopic parameters as the delay and duration of rf transmit and receive gates, rf phase, sampling times, and such imaging parameters as rf pulse shape and gradient waveforms. The output of PULSE is a set of programs that can be loaded into a hardware pulse programmer. With PULSE, any desired NMR or MRI pulse sequence can be programmed quickly and easily.

Cellular composition of rat bone marrow stroma. Antigen-defined subpopulations

Although stromal cells establish the architecture of mammalian bone marrow and organize hemopoiesis, the interrelationships among their macrophage, fibroblastic, endothelial, and adipocyte-like components are not wholly understood. Using murine monoclonal antibodies to cultured adherent cells of rat bone marrow, we observed that the predominant fibroblastoid cells grown from marrow differed from those of non-hemopoietic organs. The marrow type bore a detectable quantity of the ST3 but not ST4 antigen, whereas those from lung, diaphragm, and epididymal fat pad, bore more ST4 than ST3. Those from spleen were an equal mix of both types. Although the tissue distribution of the ST3 antigen was similar to that of Thy-1, it was not identical, and in the brain, the two structures were localized in different areas. While none of the ST3, ST4 (fibroblast directed), or BN(MB)35 (myeloid directed) antibodies recognized fat cells cultured from marrow, the ST10 antibody, selected for binding to marrow derived fat cells, stained peripheral adipose cells, unidentified aglobular cells in areas of fat cell formation, and macrophages, but not fibroblasts. On the basis of these observations, we suggest that the fibroblastoid cells of the marrow are different from those of non-hemopoietic tissues.

The gene for prolactin-inducible protein (PIP), uniquely expressed in exocrine organs, maps to chromosome 7

The hormonally responsive prolactin-inducible protein (PIP) gene is expressed in benign and malignant breast tumor tissues and in such normal exocrine organs as sweat, salivary, and lacrimal glands. In this communication we report the regional chromosome localization of the PIP gene locus to chromosome 7 by Southern hybridization to DNA from human-hamster somatic cell hybrids, and to 7q32-36 by in situ hybridization.

Varying capacities for replication of rat adipocyte precursor clones and adipose tissue growth

Rat adipocyte precursor populations contain clones varying in capacity for replication. In this study we explored factors controlling the frequency of clones of varying replicative capacities (clonal composition). We also explored the relationship between this frequency and fat depot growth. In perirenal and epididymal depots clonal composition was identical bilaterally; perirenal depots contained more extensively replicating clones. Although there were large interanimal differences in clonal composition, variation between animals was always in the same direction for both depots. Clonal composition was unaffected by undernutrition while with animal growth the frequency of the most extensively replicating clones was reduced. Differentiation of precursors occurred in all clones, while differentiation did not occur in skin fibroblasts cloned under identical conditions. Clonal composition and mature fat cell number were related in that fat cell numbers were identical bilaterally in both depots and increased more extensively with growth in perirenal than epididymal tissue. We conclude (a) that clonal composition of adipocyte precursor populations is regulated genetically and by age, (b) that this composition determines, at least in part, the capacity for adipose depot growth.

Lymph node metastasis and retroperitoneal lymphadenectomy in ovarian cancer

While clinicians are devoting themselves to the study of the behaviour of ovarian cancer as well as to the search for more effective therapeutic modalities, little attention has been paid to an important route of metastasis in this group of diseases: retroperitoneal spread through the lymphatic pathway. The purpose of this report is to present a 5-year experience of a prospective study on lymph node metastasis in patients with ovarian cancer through retroperitoneal lymphadenectomy at the Peking Union Medical College Hospital. From June 1982 through May 1987, retroperitoneal lymph node dissection was performed in 105 cases of ovarian cancer. Seventy-seven (73.3%) were histologically diagnosed as cancer of epithelial origin, and 28 (26.7%) as germ-cell tumours. The overall incidence of retroperitoneal positive nodes was 54.3% (57/105). The incidence of positive pelvic nodes was 46.7% (49/105), and that of positive para-aortic nodes was 37.5% (30/80). In 69 patients who underwent systemic lymphadenectomy, 39 were found to have glandular involvement; in these 39 patients both aortic and pelvic nodes were positive in 19 cases (48.7%), aortic nodes were positive and pelvic nodes negative in 7 cases (18.0%), and pelvic nodes were positive and aortic nodes negative in 13 cases (33.3%). Preoperative lymphography was performed in 30 cases. The positive and negative correspondence rates with the pathological findings were both 83.3%. In 38 cases in which the primary cancer originated in the left ovary, 17 (44.7%) were found to have positive pelvic nodes, whereas in 25 cases with primary cancer arising in the right ovary only 2 (8%) had metastasis of the ipsilateral pelvic nodes. The lymph nodes obtained from 22 patients with positive nodes and sufficient preoperative chemotherapy were carefully examined under the microscope for the effects of the drugs. Some cellular degeneration of the lymph node metastasis was observed in only one of the 15 cases of epithelial cancer, and no response at all was noted in three cases of immature teratoma. Cellular degeneration accompanied by extensive necrosis was demonstrated in the metastatic tumours of the lymph nodes in all four cases of endodermal sinus tumour. Seventy-two patients were followed-up for at least 2 1/2 years. The rate of complete remission was 46.7% (14/30) in patients with negative nodes, but only 33.3% (14/42) in those with positive nodes. However, the difference was not statistically significant.

[BCG-polysaccharides-nucleic acid and its effect in the prophylactic treatment of the common cold]

The polysaccharides-nucleic acid fraction extracted from BCG was found out to be a good adjuvant. Through the activation and protective of the suppressed body immune system, particularly the macrophages and T cells, it gave good protection to the Sendai virus airway infection of C57BL mice, and clinical effect on the common cold susceptible.

Reversible inhibition of ethylene action and interruption of petal senescence in carnation flowers by norbornadiene

The inhibitory effects of the cyclic olefin 2,5-norbornadiene (NBD) on ethylene action were tested in carnation (Dianthus caryophyllus L. cv White Sim) flowers. Treatment of flowers at anthesis with ethylene in the presence of 500 microliters per liter NBD increased the concentration of ethylene required to elicit a response (petal senescence), indicating that NBD behaves as a competitive inhibitor of ethylene action. Transfer of flowers producing autocatalytic ethylene and exhibiting evidence of senescence (petal in-rolling) to an atmosphere of NBD resulted in a rapid reduction in ethylene production, petal 1-aminocyclopropane-1-carboxylic acid synthase activity, 1-aminocyclopropane-1-carboxylic acid content, and ethylene forming enzyme activity. Removal of NBD resulted in recovery of ethylene biosynthesis. These results support the autocatalytic regulation of ethylene production during the climacteric stage of petal senescence and suggest that continued perception of ethylene is required for maintenance of ethylene biosynthesis. The inhibition of ethylene action by NBD after the flowers had reached the climacteric peak was associated with interruption of petal senescence as evidenced by reversal of senescence symptoms. This result is in contrast to the widely held belief that the rate of petal senescence is fixed and irreversible once petals enter into the ethylene climacteric.