Cluster headache pathogenesis: A pupillometric study

Thirty-two cluster headache patients and healthy controls (n = 16-20 for the various tests) were examined by means of a Whitaker pupillometer during pain-free intervals. Eye drops of the sympathomimetic agents tyramine, hydroxyamphetamine, and phenylephrine were instilled into the conjunctival sacs on separate occasions, and pupillary diameters recorded at standard time intervals. The mydriatic responses of the two pupils were compared. A moderate, but statistically significant, basal relative miosis was found on the pain side in cluster headache. The symptomatic-side pupils were less responsive than their counterparts when stimulated with tyramine and hydroxyamphetamine, the difference being statistically significant for the OH-amphetamine test. With the phenylephrine test, however, the mydriasis on the symptomatic side significantly exceeded that of the contralateral pupil. This pattern of reactions does not quite correspond to those of "ordinary" Horner's syndrome (1st, 2nd, and 3rd neuron lesion). There are, however, gross similarities with the recently reported pattern in central sympathetic neuron dysfunction. In cluster headache there is probably a "Horner-like picture" rather than a proper Horner's syndrome.     

Unexplained hepatitis C virus antibody seroconversion in established blood donors

BACKGROUND: Understanding of the epidemiology and natural history of hepatitis C virus (HCV) infection is incomplete without reference to the early phase of infection. The prevalence of HCV infection is well documented in numerous reports. The seroconversion pattern in previously antibody-negative blood donors provides a model for the study of the incidence and transmission of HCV infection. STUDY DESIGN AND METHODS: Records of HCV antibody tests at the West Midlands Blood Transfusion Centre were reviewed to determine the seroconversion rate in 1994 among previously anti-HCV-negative blood donors. Seroconverting donors were counseled to investigate the possible routes of infection. RESULTS: In 1994, blood donations (n = 256,935) were collected from 149,370 donors; 24 donors (0.016%; 1/6224) were positive in the screening enzyme-linked immunosorbent assay (ELISA) and the third- generation recombinant immunoblot assay (RIBA-3). Two donors previously negative for HCV antibody in ELISA were positive in both tests in 1994. Four donors positive in ELISA and indeterminate in RIBA-3 in 1993 reacted positively in both tests in 1994. One donor negative for HCV antibody on previous screening reacted positively in ELISA and was indeterminate in RIBA-3 in 1994 and has become positive in both tests in 1995. A further 43 donors negative for HCV antibody on previous screening reacted positively in ELISA and were indeterminate in RIBA-3 in 1994. CONCLUSION: Documented seroconversion can take place in the absence of exposure to recognizable risk factors for the infection. The index donation or the donation immediately preceding seroconversion may be positive for HCV RNA in the polymerase chain reaction.     

Optimization of diagnostic imaging use in patients with acute abdominal pain (OPTIMA): Design and rationale

Background

Superior mesenteric injury is a rare entity but when it occurs, short bowel syndrome is one of the uninvited results of the emergency surgical procedures.

Case presentation

We present a 19-year-old boy with blunt abdominal trauma which caused serious mesenteric injury. Because ultrasound revealed free intraabdominal fluid, he underwent emergency laparotomy. Adequate vascularization of approximately 20 cm of proximal jejunal segment and approximately 20 cm of terminal ileum was observed. Nevertheless, the mesentery of the rest of the small intestine segments was ruptured completely. We performed an end-to-end anastomosis between a distal branch of the superior mesenteric artery in the mesentery of the ileal segment and a branch of the superior mesenteric artery using separate sutures of 7.0 monofilament polypropylene. The patient's gastrointestinal passage returned to normal on the postoperative day 2. He recovered without any complication and was discharged from hospital on the postoperative day seven.

Discussion

In this case report, we emphasize the importance of preservation of injured mesenteric artery due to abdominal trauma which could have resulted in short bowel syndrome.     

Factors influencing 20-hour increments after platelet transfusion

The 20-hour posttransfusion platelet count determines transfusion policy for patients requiring platelet support, and yet factors influencing the 20-hour count have been poorly defined. The clinical factors influencing both the 1- and 20-hour corrected count increment (CCI), were studied in 623 human leukocyte antigen (HLA)-unmatched platelet transfusions in 108 patients. The 1- and 20-hour CCIs were highly correlated (r = 0.67, p less than 0.001). On average, the 20-hour CCI was 64 percent of the 1-hour CCI. Multiple linear regression analyses identified splenectomy, bone marrow transplantation, disseminated intravascular coagulation, administration of amphotericin B, palpable spleen, and HLA antibody grade as the major factors influencing the 20-hour posttransfusion CCI. Platelet-specific antibodies, number of concurrent antibiotics, clinical bleeding, and temperature did not significantly influence the 20-hour posttransfusion CCI. The 1-hour CCI was the only significant factor influencing the 20-hour CCI in a regression model containing the 1-hour CCI and the above factors. Thus, the same clinical factors exert a major influence on the CCI at both 1 and 20 hours after platelet transfusion, with no evidence that any factor has more influence at 20 hours after transfusion than at 1 hour.     

Hemostatic enzyme generation in the blood of patients with hereditary protein C deficiency

The presence of hereditary protein C deficiency has been shown to predispose patients to the development of venous thrombosis. We used radioimmunoassays for the protein C activation peptide (PCP) and the prothrombin fragment F1 + 2 to quantitate the extent of in vivo activation of protein C by thrombin-thrombomodulin and prothrombin by factor Xa, respectively, in the blood of individuals with this clinical disorder. A total of 46 protein C deficient subjects from 18 kindreds were studied. In 23 nonanticoagulated patients with an isolated deficiency of protein C, the mean level of PCP was substantially reduced while the mean concentration of F1 + 2 was significantly elevated as compared with normal controls (1.10 pmol/L v 1.78 pmol/L, P less than .0005 and 2.54 nmol/L v 1.51 nmol/L, P less than .0005, respectively). The metabolic behavior of 131I-F1 + 2 was found to be similar in protein C deficient patients and normal individuals. However, we were unable to establish a significant correlation between decreased PCP levels and increased F1 + 2 measurements in these 23 patients. This study demonstrates that heterozygous protein C deficient individuals with equivalent plasma levels of the zymogen may have markedly different biochemical profiles when assay techniques are used that quantitate the in vivo activity of the coagulation system. Six individuals from three pedigrees were identified as having combined deficiencies of protein C and either antithrombin III or protein S; the genetic basis for the combined deficiency state was determined in two of the kindreds. Finally we observed that hemostatic system activity as measured by the PCP and F1 + 2 assays is markedly suppressed in protein C deficient patients who are chronically anticoagulated with coumarin derivatives.     

Acellular extracellular matrix anal fistula plug： Results in high fistula-in-ano awaited

Song et al have reported a 100% success rate of acellular extracellular matrix （AEM） anal fistula plug in low fistula-in-ano. The results with this product in high fistula-in-ano are keenly awaited.