The neonatal piglet as a model for human neonatal carnitine metabolism

Investigations concerning carnitine metabolism and possible requirements for exogenous carnitine in human preterm neonates are limited by ethical considerations. The neonatal piglet is a potential animal model for these investigations. Tissue carnitine concentrations were determined in fetuses from cross-bred domestic gilts at stages of gestation corresponding to those of neonates found in neonatal intensive care units. Fetal piglet plasma and red blood cell carnitine levels decreased from approximately 90 d to term. Skeletal muscle carnitine increased from 60 d to term. Temporal changes in fetal carnitine concentrations in plasma, red blood cells and skeletal muscle throughout gestation are similar to the pattern reported by our laboratory for the human neonate. Cardiac muscle carnitine increased earlier than skeletal muscle but also continued to increase to term. Carnitine concentrations in fetal liver, kidney and intestine were maximal at 90 d and decreased until term. Similarities in physiology, metabolism and profiles of tissue carnitine concentration between the newborn piglet and the human neonate indicate that the neonatal piglet is an appropriate animal model for investigations concerning neonatal carnitine metabolism.     

Significance of H1 and H2 receptors in the human nose: rationale for topical use of combined antihistamine preparations

The aim of this experiment was to study the importance of histamine H1 and H2 receptors in the human nose. We therefore provoked 25 healthy human subjects with histamine after local pretreatment with the H1 receptor antagonist, chlorpheniramine maleate, the H2 receptor antagonist, ranitidine hydrochloride, and a combination of these two antihistamines. The histamine-induced increase in nasal airway resistance was 52% inhibited by combined use of the two antihistamine sprays (p less than 0.05), 22% by chlorpheniramine alone (p less than 0.05), and 29% by ranitidine. The two sprays together were significantly better than the H1 antagonists alone (p less than 0.05). These results suggest an equal importance of H1 and H2 receptors in nasal blood vessels, and an additive effect of H1 and H2 antihistamines. Although chlorpheniramine effectively blocked tickling and the reflex-mediated symptoms, sneezing and hypersecretion, ranitidine had no effect, which suggests an H1 and not an H2 effect on sensory nerve endings in the airway epithelium.     

Increasing frequency of acute myeloid leukemia complicating Hodgkin's disease: a review

Between the years 1911 and 1969, there were 16 reported cases of Hodgkin's disease terminating in acute myeloid leukemia. During the period from 1970 to 1978, the number reported was 161. Other severe complications of Hodgkin's disease (second malignancies and infections) also seem to appear with increased frequency after the introduction of modern aggressive high-energy radiation therapy and combination chemotherapy. It is thus desirable to search for alternative methods of treatment of Hodgkin's disease.     

Colorectal cancer screening of African Americans by internal medicine resident physicians can be improved with focused educational efforts

Colorectal cancer causes significant morbidity and mortality in the United States. African Americans are disproportionately affected by this malignancy. There is evidence to suggest that resident physicians inconsistently screen for colorectal cancer in African Americans, perhaps because of a deficiency in knowledge and limited resources. This study evaluated internal medicine resident physicians' colorectal screening practices in African Americans prior to and following a focused educational intervention. A medical record review of internal medicine resident physicians' adherence to colorectal cancer screening recommendations was conducted. Physicians' performance of rectal exams, fecal occult blood testing, flexible sigmoidoscopy and colonoscopy was evaluated for six months prior to and six months following an educational intervention that focused upon issues related to racial disparities in colorectal cancer. Statistical significance was assessed using Fischer's exact test. There were 116 patients included in the preintervention assessment and 132 patients included in the postintervention assessment. There was no statistical significance in the rate at which rectal exams (p=0.6605) and fecal occult blood testing (p=0.7748) were performed prior to and following the educational initiative. However, there was a statistically significant difference in the rate at which endoscopic assessments (p<0.0001) were performed. Educational interventions that are focused upon racial disparity in colorectal cancer may improve resident physicians' performance of endoscopic exams in African Americans. Continued effort to enhance resident physicians' colorectal cancer screening practices in African Americans is important.     

Infraposition of ankylosed permanent maxillary incisors after replantation related to age and sex.

The extent of infraposition of replanted and subsequently ankylosed permanent incisors was examined in a longitudinal study of 52 patients. Study cast models were made during the follow-up period. Infraposition was evaluated on frontal photos of the study cast models taken parallel with the occlusal plane. The extent of infraposition was defined as the difference between the position of the incisal edge of the replanted incisor and the adjacent non-injured incisor in apico-coronal direction, measured with a digital caliper at 50x magnification of the negatives. The precision of this measuring procedure was 2.9% and the accuracy 2.0%. Marked infraposition was identified if the tooth was traumatized before the age of 16 in boys and before the age of 14 in girls. In addition, infraposition was observed when ankylosis developed in patients aged 20-30 years, with a yearly mean infraposition rate of 0.07 mm/year (range: 0.02-0.21 mm/year) in males and 0.07 mm/year (range: 0.00-0.12 mm/year) in females. The latter findings supported the concept of slow continuous eruption of the teeth. This phenomenon may have implications not only for the treatment of traumatized teeth but also for the treatment of tooth loss by osseointegrated implants, which represent an analogue to the ankylosed replanted tooth.