Plain Film Recognition of Giant Colonisc Diverticulum

Four cases of giant colonic diverticula are presented with emphasis on plain film recognition employing the "balloon sign", a persistent, rounded lucency which is consistently seen on any abdominal scout film or survey. The importance of this finding is even greater in the absence of gastrointestinal complaints in view of the complication of torsion and perforation     

Ectopic Gallstone as a Cause of Gastric Outlet Obstruction

Callstone ileus is, of course, a well known cause of small bowel obstruction. A gallstone, however, is a very rare cause of gastric outlet obstruction. Three cases illustrating this phenomenon are exhibited. Radiographs were diagnostic in two of the studies. All three patients did well postoperatively.     

Presence of an amphipathic helical segment and its relationship to biological potency of calcitonin analogs

The conformational properties of a number of calcitonin analogs were studied by circular dichroism. The ability of dimyristoylphosphatidylglycerol, lyso-phosphatidycholine or sodium dodecyl sulfate to induce the formation of more highly ordered structures in these peptides was also assessed by circular dichroism. In all cases sodium dodecyl sulfate induced the largest change in the circular dichroism spectra of the peptides. Salmon calcitonin and its analogs were slightly more helical in the presence of the anionic phospholipid than in the presence of the zwitterionic detergent lysophosphatidylcholine while the reverse is true for human calcitonin and its analogs. Some of the calcitonin analogs convert turbid suspensions of phosphatidylglycerol to a clear solution from which the phospholipid is no longer readily sedimentable by centrifugation. Several of the physical properties of these peptides could be correlated with their biological activity. Generally peptides which showed no hypo-calcemic activity had the least negative mean residue ellipticities at 222 nm. Only biologically active analogs were able quantitatively to solubilize dimyristoyl-phosphatidylglycerol and in this solubilized form the peptides have a higher helical content. More active derivatives exhibit larger increases in helix content in the presence of this phospholipid. Inactive analogs had the least negative mean residue ellipticities at 222 nm in the presence of lysophosphatidylcholine or sodium dodecyl sulfate. Thus, the ability of a calcitonin analog to form structures of higher helical content in the presence of amphiphiles is a requirement for the analog to exhibit high potency in assays of biological activity.     

Clinical Assessment of Gestational Age

There is disagreement among authors as to what criteria are most reliable in assessing postnatal fetal age. A comparison–for objectivity, accuracy, and frequency of use– of specific criteria was made using three independent examiners at different educational levels: a second-year medical student, a perinatal nurse practitioner, and a pediatrics resident. It was shown that trained examiners develop favorite criteria which differ among examiners and thus sacrifice accuracy; however, accurate assessment of fetal age can be accomplished by an examiner with minimum clinical knowledge.     

Oxygen and Redox-Active Drugs: Shared Toxicity Sites

Oxygen and Redox-Active Drugs: Shared Toxicity Sites. Brown,O.R. and Seither, R.L. (19S3).Fundam. Appl. Toxicol. 3:209-214.Paraquat and nitrofurantoin can accept single electrons and,under appropriate conditions in tissues and cells, can passthese electrons to oxygen, thus participating in redox cycling.Similarities in the response of the target organ (the lung)and in subsequent pathology have also been observed among animalspoisoned by oxygen and by these chemicals. We report evidenceprimarily obtained from Escherichia coli for common biochemicalsites of toxicity for these agents. Common sites for oxygenand paraquat involve biosynthesis of specific amino acids, inductionof genetic stringency via unloaded tRNAs resulting from aminoacid deficiencies, decreased thiamin content, and impaired biosynthesisof pyridine nucleotide coenzyme biosynthesis for paraquat andoxygen. Inhibition of specific amino acid biosynthesis and inductionof stringency also have been observed for nitrofurantoin. RNAand DNA biosynthesis are also impaired by oxygen; this has notbeen examined for paraquat or nitrofurantoin. There is a biochemicalbasis and preliminary data to support inhibition of NAD biosynthesisas a component of mammalian toxicity for these agents. Niacinmay act to circumvent the consequences of the biochemical lesionat quinolinate phosphori-bosyl transferase in NAD biosynthesis.     

A light for anaesthetists

A new type of lighting device is incorporated into the ether screen cross-bar, enabling better illumination of the patient's face. A 12-V, DC power supply is used. The temperature, with vacuum-assisted cooling, should not cause burns to an unconscious patient. Assessment of patient colour was evaluated and found to be reliable. The lamp must not be used with flammable anaesthetic agents.     

Verrucous carcinoma of the laryn

Verrucous carcinmoma of the larynx is an uncommon but distinct variety of well differentiated squamous carcinoma and accounts for 1–2% of all laryngeal squamous carcinomata. Awareness of the condition both by clinician and histopathologist is essential otherwise the diagnosis may not be made. From a review of the literature and personal assessment of the cases presented here it would appear that local conservative endoscopic treatment with careful follow-up may be the treatment of choice for certain verrucous carcinomata. Such treatment may be either suction diathermy or cryosurgery or laser surgery. Anaplastic transformation has been said to occur following irradiation of these tumours, though this view is not held by all clinicians, some of whom recommend radiotherapy for selected cases.     

The Chromatography of Hemins from Normal and Abnormal Human Erythrocytes

1. Erythrocyte hemins, extracted with acid-acetone, exhibited multiplecomponents on two chromatographic systems. However, this heterogeneity canbe explained by various physicochemical properties of hemin in solution anddoes not imply that heme, when attached to globin in the native hemoglobinmolecule, is heterogeneous.

2. The presence of a non-polar fraction may be accounted for by esterification of protohemin as a result of reaction with small amounts of methanol contaminating the acetone and/or the presence of some un-ionized protoheminmolecule in solutions of low pH.

3. The presence of poorly soluble fractions is probably the result of polymerization of the hydroxyhemin molecule into so-called - and -hematins.

4. The formation of mesohemin is considered unlikely, but the formation ofdeuterohemin or hematohemin cannot be excluded.

5. No changes in hemin chromatographic patterns were noted in disease.

6. It is necessary to evaluate reports concerning chromatographic heminheterogeneity in the light of the artifacts described above before attributingphysiologic or pathogenetic significance to the findings.

Submitted on August 6, 1963 Accepted on September 14, 1963