From the Cover: Strong profiling is not mathematically optimal for discovering rare malfeasors

The use of profiling by ethnicity or nationality to trigger secondary security screening is a controversial social and political issue. Overlooked is the question of whether such actuarial methods are in fact mathematically justified, even under the most idealized assumptions of completely accurate prior probabilities, and secondary screenings concentrated on the highest-probablity individuals. We show here that strong profiling (defined as screening at least in proportion to prior probability) is no more efficient than uniform random sampling of the entire population, because resources are wasted on the repeated screening of higher probability, but innocent, individuals. A mathematically optimal strategy would be “square-root biased sampling,” the geometric mean between strong profiling and uniform sampling, with secondary screenings distributed broadly, although not uniformly, over the population. Square-root biased sampling is a general idea that can be applied whenever a “bell-ringer” event must be found by sampling with replacement, but can be recognized (either with certainty, or with some probability) when seen.     

Rhinocerebral mucormycosis: results of aggressive surgical debridement and amphotericin B

Rhinocerebral mucormycosis is a fulminant, devastating fungal disease. The use of amphotericin B, combined with aggressive surgical debridement, has increased survival rates from approximately 20% to 70%. Eleven patients with this rare disease have been treated over the past 6 years. Therapy with amphotericin B was begun in all patients as soon as the diagnosis of mucormycosis was suspected. Seven patients underwent aggressive surgical debridement; all seven had disease involving the sphenoethmoidal complex, requiring external ethmoidectomy with or without sphenoidotomy. Six patients had maxillary sinus disease, requiring Caldwell-Luc antrostomy or maxillectomy. Three patients required orbital exenteration. Surgery was performed within 24 hours of diagnosis on all but two of our patients. Despite prompt diagnosis, aggressive surgical debridement, therapy with amphotericin B, and correction of metabolic acidosis, our mortality rate was 82%. Rhinocerebral mucormycosis remains a rapidly progressive, frequently fatal disease.     

Cognitive slowing in Parkinson's disease resolves after practice

OBJECTIVE: To assess the effect of dopaminergic repletion on working memory in Parkinson's disease. METHODS: The role of dopaminergic state on working memory in patients with Parkinson's disease was determined using the Sternberg item recognition paradigm, a continuous performance task that dissociates the motor and cognitive components of response time. Ten patients with Parkinson's disease were tested in an "on" state (on dopaminergic drug treatment) and a practical "off" state in two sessions held one week apart in counterbalanced order; 10 controls matched for age and education were studied at the same time points. RESULTS: Patients with Parkinson's disease showed impaired working memory, independent of motor slowing. During session 1, the performance of the patients was worse than the controls, regardless of dopaminergic state. The patients showed a significant improvement in the cognitive component of task performance during the second session, such that they no longer differed from the controls. The performance of the control subjects remained stable over the two sessions. CONCLUSIONS: Working memory performance of patients with Parkinson's disease did not change in association with dopaminergic state; rather, the performance improved over time. The pattern of improvement over time suggests a delay in proceduralising the task, similar to the deficits shown by such patients in procedural learning of other tasks.     

A comparison between the effectiveness of epidural analgesia and parenteral pethidine during labor

The study was aimed to define parturients' opinion on either epidural analgesia or intravenous pethidine, and to determine the effect of both analgesics after delivery. We interviewed and examined 401 consecutive parturients who requested analgesia during the beginning of their active stage of labor. Of those, 131 women requested and underwent epidural analgesia, and 270 received parenteral pethidine. The pain experienced before admission of any analgesia, was significantly higher in the epidural group than in the parental group (mean visual analog scale (VAS) score 8.9 and 8.4, respectively; P=0.004). However, after analgesics, women from the epidural analgesia experienced significantly less pain during labor as compared to those receiving pethidine (mean VAS scores 5.05 vs. 9.14, respectively; p<0.001). The pain scores 24 h after labor were significantly lower in patients who underwent epidural analgesia (1.69 vs. 2.13, respectively; p<0.001). We conclude that epidural analgesia is more effective than parenteral analgesia in pain and discomfort relief. This method is helpful also the day after delivery. Thus, epidural analgesia should be strongly recommended to all patients who do not have any medical contraindications to this method of treatment.     

An intervention program to reduce the number of hospitalizations of elderly patients in a primary care clinic

Background  

The elderly population consumes a large share of medical resources in the western world. A significant portion of the expense is related to hospitalizations.     

Pretargeted radioimmunotherapy (PRIT) for treatment of non-Hodgkin's lymphoma (NHL): initial phase I/II study results

Pretargeted radioimmunotherapy (PRIT) was investigated in patients with non-Hodgkin's lymphoma (NHL). The PRIT approach used in this study is a multi-step delivery system in which an antibody is used to target streptavidin to a tumor associated antigen receptor, and subsequently biotin is then used to target 90Y radioisotope to the tumor localized streptavidin. A chimeric, IgG1, anti-CD20 antibody, designated C2B8 or Rituximab, was conjugated to streptavidin (SA) and administered to patients with NHL. Thirty-four hours later, a clearing agent, synthetic biotin-N-acetyl-galactosamine, was administered to remove non-localized conjugate from the circulation. Finally, a DOTA-biotin ligand, labeled with 111In for imaging and/or 90Y for therapy was administered. Ten patients with relapsed or refractory NHL were studied. In three patients, the C2B8/SA conjugate was radiolabeled with a trace amount of 186Re in order to assess pharmacokinetics and biodistribution using gamma camera imaging. Seven patients received 30 or 50 mCi/m2 90Y DOTA-biotin. Re-186 C2B8/SA images confirmed that the conjugate localized to known tumor sites and that the clearing agent removed > 95% of the conjugate from the circulation. Radiolabeled biotin localized well to tumor. Unbound radiobiotin was rapidly excreted from the whole body and normal organs. The mean tumor dose calculated was 29 +/- 23 cGy/mCi 90Y and the average whole body dose was 0.76 +/- 0.3 cGy/mCi 90Y, resulting in a mean tumor to whole body dose ratio of 38:1. Only grade I/II non-hematologic toxicity was observed. Hematologic toxicity was also not severe; i.e., five of the seven patients who received 30 or 50 mCi/m2 of 90Y-DOTA-biotin experienced only transient grade III (but no grade IV) hematologic toxicity. Although six of ten patients developed humoral immune responses to the streptavidin, these were delayed and transient and hence may not preclude retreatment. Six of seven patients who received 30 or 50mCi/m2 90Y achieved objective tumor regression, including three complete and one partial response. The estimate of tumor to whole body dose ratio (38:1) achieved with PRIT in these NHL patients is higher than has been achieved in other studies using conventional RIT. Toxicity was mild and tumor response encouraging. PRIT clearly deserves additional study in patients with NHL.     

Results of conservative surgery for middle ear cholesteatoma

A retrospective study was carried out to analyze treatment results for cholesteatoma at the University of Iowa Hospitals and Clinics. All patients undergoing primary surgical treatment from January 1, 1969 to December 31, 1973 were followed through October 1976. Treatment failures were based on the occurrence of postoperative cholesteatoma. The probability of being disease free for periods up to five years after original surgery was then estimated for each type of operation. Postoperative cholesteatoma occurred after atticotomy in 17%, intact canal wall mastoidectomy in 35%, and modified radical mastoidectomy in 9%. The postoperative cholesteatoma rate in the group having intact canal wall mastoidectomy was more than twice as high for those patients under age nine. The likelihood of being disease free five years after intact canal wall surgery was estimated to be 36% using the life table method. Disease recurrence was significantly higher after intact canal wall surgery compared to other surgical methods. The effectiveness of this method should be evaluated in a randomized, prospective manner to minimize patient selection and treatment bias.