The fist model for nasal packing.

Epistaxis is a common ear, nose and throat emergency. A variety of nasal packs are available to control the bleeding by tamponade. Training of junior doctors to insert nasal packs is difficult when dealing with a bleeding patient. We discovered a readily available and simple model to enable trainees to learn the method of nasal packing.     

Psoas abscess: Difficulties encountered

From 1961 to 1989, 67 patients underwent various surgical procedures for psoas abscess. Retrospective analysis was undertaken in an effort to determine optimal surgical therapy. Forty patients were cured with one operation. Twenty-one patients required two operations, four patients required three operations, and two patients required more than three operations. The reason for failure of treatment was failure to resect the diseased bowel or to drain the psoas abscess adequately. A technique to recognize and treat the abscess definitively will be illustrated. The most common etiologies were Crohn's disease in 49 patients, postoperative sepsis in eight patients, and complications of renal disease in four patients. The length of hospital stay ranged from 5 to 392 days (mean, 26 days). There were two deaths. Failure to recognize and treat psoas abscess results in considerable morbidity.Poster presentation at the meeting of The American Society of Colon and Rectal Surgeons, St. Louis, Missouri, April 29 to May 4, 1990.     

Use of post-mortem human synaptosomes for studies of metabolism and transmitter amino acid release

Synaptosomes have been prepared from human brain obtained at autopsies carried out up to 24 h postmortem (p.m.). They showed generally good retention of morphology, as well as accumulation of tissue potassium and linear rates of oxygen uptake. In response to veratrine depolarization they showed increased respiration rate, decreased tissue potassium content and the specific release of transmitter amino acids. Regression analysis indicated that metabolically and functionally active preparations may be obtained up to ca. 25 h p.m. Preparations obtained from patients dying with brain injury were inactive.     

Correlation of light-induced changes in retinal extracellular potassium concentration with c-wave of the electroretinogram.

1. Double-barrel, potassium-specific microelectrodes have been used to measure light-induced transient changes in [K+]o in the frog eye cup preparation. These changes in [K+]o have been termed the potassioretinogram (KRG). 2. The KRG consists of two components: a rapid increase in [K+]o in the proximal retina and a slow decrease in [K+]o in the distal retina. 3. The KRG decrease has the rhodopsin action spectrum, is maximal in the photoreceptor layer, persists after aspartate treatment, and has an increment threshold curve which saturates at moderate background intensities. The rhodopsin rods are, therefore, most likely the only neurons which generate this ionic change, although the Müller (glial) cells may also be involved in this process. 4. The KRG decrease has the same time course as the c-wave of the electroretinogram for all variations in the stimulus parameters, including intensity, duration, and chromaticity. 5. It is suggested that the c-wave may be produced by the pigment epithelial cells as they hyperpolarize in response to the decrease in [K+]o around the photoreceptors.     

PII component of the toad electroretinogram.

1. The PII component of the electroretinogram (ERG) is comprised of the b-wave and the DC component and is thought to reflect bipolar cell activity. Although the b-wave is generated in large part by a K+/Müller cell mechanism, the origin of the DC component is unclear. In this paper we detail our investigation of the origin of the DC component. We hypothesize that the DC component is generated by a K+/Müller cell mechanism identical to that involved in b-wave generation. 2. We studied the ERG in the dark-adapted, isolated retina preparation of the toad, Bu fo marinus. We used K+ ion-sensitive microelectrodes (K+ISM), as well as conventional intra- and extracellular microelectrodes, to record [K+]o changes, the vitreal ERG, and Müller cell responses. 3. We used the excitatory amino acid receptor agonist N-methyl-DL-aspartate (NMDLA) to inhibit light responses of third-order neurons and thereby eliminate most of the ERG M-wave. In the absence of the M-wave, the ERG consisted of PII and PIII. We then superfused the retina with a solution containing both kynurenic acid (KYN) and 2-amino-4-phosphonobutyric acid (APB), which together inhibit all retinal responses proximal to the photoreceptors. In the presence of KYN and APB, the ERG consisted only of PIII. Using digital subtraction, we reconstructed PII. To our knowledge, this is the first report of the isolation of a PII component in the ERG of a nonmammalian species. 4. Using K+ISMs, we recorded the distal K+ changes in the outer plexiform layer (OPL).(ABSTRACT TRUNCATED AT 250 WORDS)