Slight Suction Research Articles

Rapid and correct identification of intestinal Bacteroides spp. with chromosomal DNA probes by whole-cell dot blot hybridization.

A dot blot hybridization procedure with 32P-labeled whole chromosomal DNA of the type strains as probes was developed as a rapid and simple method for identification of intestinal Bacteroides species. Bacterial cells were fixed onto membrane filters by slight suction, treated with 0.5 N NaOH, and hybridized with these probes. Of 65 Bacteroides strains isolated from 19 human fecal specimens, which were identified as B. fragilis, B. thetaiotaomicron, B. ovatus, B. caccae, B. uniformis, B. stercoris, B. vulgatus, B. distasonis, and B. merdae by conventional phenotypic characterization, 62 (95%) were correctly identified with this hybridization procedure.

Overcoming Difficulties in Trephining Donor Corneas for Penetrating Keratoplasty

The complication of the donor button becoming trapped inside the barrel of the trephine blade can become a frustrating situation for the surgeon who is trying to recover it. The use of a sterile medicine dropper to apply slight suction to the epithelial side of the button allows for easy and secure removal of the trapped button without the risk of distortion or direct trauma to the endothelium as could occur with other methods.

Malignant esophagopulmonary fistula treated by fiberoptic intubation of a prosthesis

ously for decompression of the bile ducts in acute obstructive suppurative cholangitis caused by stones as well as for direct stone dissolution.1o In this case the endoscopic insertion of a nasobiliary tube through the intact papilla and drainage with slight suction led to a sufficient reduction of the biliary pressure so that the flow of bile through the abdominal drain stopped immediately and the fistula closed.

New cell fusion method using polymer membrane

A porous polymer membrane of nitrocellulose or tetrafluoroethylene (TFE) was employed for fusion of Saccharomyces cerevisiae (AH22 and D13-1A) protoplasts. Protoplasts were adsorbed on the membrane with slight suction. Some part of the protoplasts was trapped in pores of the membrane as observed by electron microscopy. The membrane retaining protoplasts was placed on a selective medium. Several colonies appeared on the medium after 5–7 days incubation at 30°C. The fusion of the two strains was ascertained by DNA content and genetic markers. Fusion frequency was 1.2 × 10 −6 in the case of the TFE membrane.

Constant-rate Rainfall Infiltration: Field Experiments

Measurements of water content profiles developed under constant-rate rainfall from a simulator were reported for two field locations. The observed field profiles prior to ponding agreed with those predicted by the theory of constant-flux infiltration. The predictions are based on field measurements of sorptivity and saturated hydraulic conductivity. Soil water diffusivity was scaled from sorptivity and wet front advance measurements taken with a simple device that gives the diffusivity of the soil matrix (i.e., the soil minus macropores > 0.75 mm diam), by supplying water to the soil surface at a slight suction. This is appropriate to nonponding flux infiltration since the soil is unsaturated. The physical properties of the matrix are shown to give the time to incipient ponding. Following saturation there may be preferential flow into the macropores so the time to initiation of runoff will lag behind the time to incipient ponding.

FIELD CHAMBER MEASUREMENTS OF CO2 FLUX FROM SOIL SURFACE

Rates of carbon dioxide exchange were determined using an infrared gas analyzer in an open chamber system in a field. During 1971 a fan was used to draw air through the chamber; the measured CO2 flux was approximately 40 percent greater than the highest rate reported in the literature. In 1972 two chambers were used: one under slight suction and the other under a slight pressure (compared with atmospheric pressure). The CO2 flux from the soil surface inside the “pressure” chamber was nearly an order of magnitude lower than inside the “suction” chamber. Dispersion equations were used to separate mass flow and diffusion components of the total flux. Simplified analysis showed that mass flow could account for the large CO2 flux with slight negative pressures inside the chamber.

Voltage clamp on Helix pomatia neuronal membrane; current measurement over a limited area of the soma surface.

A method was developed, to measure during a voltage clamp the current which flows through a limited area (104 μ2) of the soma membrane. In addition to an intracellular voltage clamp electrode, a fire-polished glass micropipette is placed on the soma surface (with slight suction applied), and only the clamp current through the pipette is measured. This measurement excludes uncontrolled currents from the axon. Alternatively the membrane “spot” (area under the pipette) can be voltage clamped while the rest of the cell is kept in the resting state. The latter method is an advantage with bigger cells where homogeneous clamp over the whole surface cannot be achieved.

Simplified Breast Care

ONE of the time-consuming procedures in the care of the patient after delivery has been that of caring for the breasts and nipples. In private hospitals many physicians do not know what method of routine postpartum breast care is used unless the patient develops complications. The majority of physicians have allowed the nursing staff to determine the methods to be used so that this has largely developed into a nursing problem. The use of a sterile tray containing soap solution, water, boric acid solution, cotton balls or appliactors, and towels for the care of breasts and nipples at bath time; the application of an ointment to nipples and cleansing with water or boric acid solution before and after nursing-. these have been standard procedures over the country for years (1,5,6). Time studies carried on at Woman's Clinic of Johns Hopkins Hospital, Baltimore, Maryland (10) and Sloane Hospital for Women, New York City (2) showed that, at the time the studies were made, a total of thirty minutes was being spent in giving breast care to each patient daily. During recent years attempts have been made to simplify nursing procedures in the care of the post partum patient and at the same time maintain a high standard of care. We have found that a new plastic nipple shield fills the need for a safe, simple, easily standardized method of nipple care.1 These shields prevent rubbing and irritation from clothing, and eliminate the use of ointments, gauze, and towels. The slight suction created when they are applied keeps them in place under the breast support and helps to shorten the latent period in nursing. They protect flat or inverted nipples

DIAGNOSIS OF SYPHILIS FROM PRIMARY LESION

To the Editor: —Referring to the method described by Dr. William D. Gill inThe Journal, September 16, in which serum from the primary lesion is obtained by slight suction obtained from an improvised suction syringe: Serum for dark field spirochetal search may be obtained in a still simpler manner by placing over the lesion any of the ordinary suction tubes, such as those of Hays, Hurd, McQuaid or Waring, connected to a suction pump with mild suction; or if these tubes are unavailable, an efficient suction tube for this purpose may be improvised from the barrel of an ordinary diphtheria antitoxin syringe, inverted and connected to a suction pump by rubber tubing. No new instrument is necessary in this way, and appropriate sized suction tubes are adaptable to nearly all types of lesions, and in situations in which the apparatus suggested by Dr. Gill is difficult or impossible of

“Magic Mirror” Effects

I HAD occasion recently to coat with collodion a silver surface mirror on patent plate 2 millimetres thick. During the operation the mirror was held with one of the rubber pneumatic holders frequently used by photographers when coating or varnishing plates. As the film of collodion set, a series of interference colours disposed in concentric circles appeared immediately over the region of the suction disc of the holder. I could scarcely bring myself to encourage the idea which at once occurred to me, viz. that the slight suction of the pneumatic holder was actually deforming so thick a plate of glass and producing an appreciable concavity in its vicinity.