Safety of outpatient tonsillectomy and adenoidectomy

Recent changes in reimbursement for tonsillectomy and adenoidectomy have resulted in a large number of these procedures being done on an outpatient basis. There is still considerable controversy, however, as to the safety of this concept. We reviewed the charts of 1000 consecutive patients who underwent these procedures. Three hundred ninety-six procedures were performed as inpatient surgery and 604 were performed as outpatient surgery. Patients were considered as candidates for outpatient surgery if they met specific criteria, such as good overall medical health, no central apnea, normal bleeding history and profile, and had adequate social considerations. The inpatient group included those patients who did not meet the criteria to be outpatients. We compared the complication rates of these two groups with regard to age, type of procedure performed (tonsillectomy, adenoidectomy, adenotonsillectomy), and indication for surgery in order to determine if there was any increased risk of outpatient surgery, despite strict selection criteria. The two groups were similar in their distribution with regards to age, sex, type of procedure, and indication for surgery. The overall complication rate for the entire group was 7.9%, with an 11.8% complication rate for inpatients and 4.1% complications for outpatients. The higher complication rate among the inpatient group is probably a direct result of the selection process because this group included the higher-risk patients. On the basis of these findings, we believe that surgery of the tonsils and adenoids can be performed safely as an outpatient procedure, regardless of age, indication, or procedure, if the candidates for ambulatory surgery are carefully selected by the surgeon.     

Computerized follow-up of discrepancies in image interpretation between emergency and radiology departments

Radiographs are ordered and interpreted for immediate clinical decisions 24 hours a day by emergency physicians (EP’s). The Joint Commission for Accreditation of Health Care Organizations requires that all these images be reviewed by radiologists and that there be some mechanism for quality improvement (QI) for discrepant readings. There must be a log of discrepancies and documentation of follow up activities, but this alone does not guarantee effective Q.I. Radiologists reviewing images from the previous day and night often must guess at the preliminary interpretation of the EP and whether follow up action is necessary. EP’s may remain ignorant of the final reading and falsely assume the initial diagnosis and treatment were correct. Some hospitals use a paper system in which the EP writes a preliminary interpretation on the requisition slip, which will be available when the radiologist dictates the final reading. Some hospitals use a classification of discrepancies based on clinical import and urgency, and communicated to the EP on duty at the time of the official reading, but may not communicate discrepancies to the EP’s who initial read the images. Our computerized radiology department and picture archiving and communications system have increased technologist and radiologist productivity, and decreased retakes and lost films. There are fewer face-to-face consultations of radiologists and clinicians, but more communication by telephone and electronic annotation of PACS images. We have integrated the QI process for emergency department (ED) images into the PACS, and gained advantages over the traditional discrepancy log. Requisitions including clinical indications are entered into the Hospital information System and then appear on the PACS along with images and readings. The initial impression, time of review, and the initials of the EP are available to the radiologist dictating the official report. The radiologist decides if there is a discrepancy, and whether it is category I (potentially serious, needs immediate follow-up), category II (moderate risk, follow-up in one day), or category III (low risk, follow-up in several days). During the working day, the radiologist calls immediately for category I discrepancies. Those noted from the evening, night, or weekend before are called to the EP the next morning. All discrepancies with the preliminary interpretation are communicated to the EP and are kept in a computerized log for review by a radiologist at a weekly ED teaching conference. This system has reduced the need for the radiologist to ask or guess what the impression was in the ED the night before. It has reduced the variability in recording of impressions by EP’s, in communication back from radiologists, in the clinical follow-up made, and in the documentation of the whole QI process. This system ensures that EP’s receive notification of their discrepant readings, and provides continuing education to all the EP’s on interpreting images on their patients.     

Development of an ELISA for detection of an organophosphorus compound using monoclonal antibodies

This paper describes a specific and highly sensitive ELISA system using monoclonal antibodies in order to assay an organophosphorus compound. The soman derivative methyl phosphonic acid, p-aminophenyl 1,2,2,-trimethyl-propyl diester (MATP) served as model substance. In order to obtain antibody-producing hybridomas BALB/c mice were immunized with MATP linked onto human serum albumin (HSA). The spleen cells of immunized mice were fused with syngenic plasmacytomas of the non-producer-line X63Ag8.653 with the aid of polyethylene glycol. To eliminate undesirable cross-reaction, common screening procedures were modified by directly coating the ELISA plates with hapten. Five out of 15 positive cell-lines were cloned by limiting dilution and further propagated. The respective immunoglobulin class and subclass of the obtained monoclonal antibodies was determined. Four of which were identified as IgG₁, the other as IgG_2a. After enrichment of antibodies in ascites and their isolation by protein A-sepharose, the affinity of various monoclonal antibodies was estimated in competitive inhibition enzyme immunoassay (CIEIA) by measuring the IC₅₀ rates of free MATP. The rates were found to lie between 2.5 × 10^–6 mol/l and 4.3 × 10^–4 mol/l MATP. The IC₁₀ rate for detectable MATP concentration was 5.4 × 10^–7 mol/l MATP. Test duration was 280 min. The reactivity of the monoclonal antibodies with structurally related substances was used to check their specificity. Cross-reaction turned out to be negative. In order to develop a direct competitive ELISA, MATP was linked to horse radish peroxidase (HRPO) by adding a spacer. This helped to reduce total duration to 40 min. The detection level was further reduced to 1.3 × 10^–7 mol/l MATP (corresponding to 975 pg/25 l test-buffer) using the monoclonal antibody F71D7. Likewise, MATP was detected in goat serum, chicken serum, rabbit serum, milk and company's water in concentrations between 2.1 × 10^–7 mol/l (IC₁₀, company's water) and 4.9 × 10^–8 mol/l (IC₁₀, milk).     

Pathologic changes in murine leishmaniasis (Leishmania donovani) with special reference to the dynamics of granuloma formation in the liver

The histopathologic changes in liver, spleen, and bone marrow of BALB/c mice infected for 6 months with Leishmania donovani are described. Granulomas were the most important histologic lesions found; and the dynamics of their formation, collagen deposition, and resolution in the liver were studied. The number of hepatic granulomas increased until the eighth week and then decreased steadily. In contrast to the liver granulomas, those of spleen and bone marrow do not mature or show collagen deposition. Actual granuloma counts in the liver support the idea that mature granulomas revert to poorly formed ones and finally resolve without scarring. BALB/c mice are suitable for the study of the dynamics of granuloma formation and resolution and the survival of L donovani in an in vivo system. The relevance of these changes to the pathology of L donovani infection in man are discussed.     

Functional rescue of defective mutant connexons by pairing with wild-type connexons

We have compared the functional and structural integrity of gap junction channels assembled from a Cx45 truncation mutant with those of gap junction channels assembled from wild-type (wt) Cx45 and Cx43. These channel-forming proteins are constitutively expressed in HeLa cells. The truncation mutant lacks the last 26 amino acids of the COOH-terminus, including nine serine phosphorylation sites that are associated with regulatory processes of these channels. We determined the presence of gap junction plaques in these cells with the immunogold freeze fracture technique, which showed that plaque formation is similar in all the clones investigated. Junctional permeability was probed with calcein transfer and flow cytometry analyses and junctional conductance was measured in cell pairs with double whole-cell patch-clamp techniques. For homotypic pairing only the truncated mutant did not form permeable channels. However, coupling was restored for heterotypic channels (pairing wtCx45- or wtCx43- with mutant-connexons), whose junctional communication was not different from that of the homotypic channels. Our results indicate that the presence of gap junction plaques does not warrant functional coupling and that heterotypic trCx45/wtCx45 channels can be regulated by the intact wtCx45 connexons. This dominant-positive effect is also operative when wtCx43 are paired with trCx45 connexons.     

Psychological Correlates of Nonspecific Skin Conductance Responses

Previous research has indicated that the frequency of skin conductance responses without external stimulation or motor activity is a reliable indicator of psychophysiological states and traits. Some authors have suggested that cognitions elicit nonspecific skin conductance responses. These cognitions may resemble the stimuli that evoke a specific skin conductance response. In a within subjects design (n = 31 graduate students) the onset of nonspecific skin conductance responses triggered a signal for the subject to rate cognitions on several indices. These ratings ("absent" to "fully present") were compared with samples in the absence of phasic electrodermal activity. The subjects' current concerns, negative emotion, subjective arousal, and inner speech were rated to be significantly more intense at the time of nonspecific skin conductance responses compared to electrodermal nonresponding periods. Cognitive processes seem to be concomitants of nonspecific skin conductance responses.     

Cholate-dependent killing of Giardia lamblia by human milk.

We showed previously that nonimmune human milk (NHM) kills Giardia lamblia trophozoites in vitro and presented evidence that killing requires the bile salt-stimulated lipase of milk. Since this enzyme is activated by bile salts, killing should be dependent on the presence of bile salts. We now show that killing by fresh NHM or NHM stored at -70 degrees C is totally dependent on sodium cholate (a bile salt). With less than 0.4 mM cholate, no parasites were killed, whereas with 1 mM cholate, greater than 99.7% were killed by 5% NHM in 30 min. Moreover, killing activity was completely heat labile. The G. lamblia-killing activity of human milk was greatly altered by storage at -10 or -20 degrees C. In less than 23 days, the 50% lethal dose decreased, cholate dependence was lost, and killing activity became heat stable. In contrast, the activity of milk stored at -70 degrees C remained unchanged. Milk lipase activity, like killing activity, became cholate independent during storage at -10 or -20 degrees C. On the basis of these results, we hypothesize that killing of G. lamblia by fresh NHM or NHM stored at -70 degrees C depends on bile salt-stimulated lipase, which must be activated by bile salts. In contrast, NHM stored at -20 degrees C accumulated free fatty acids which kill G. lamblia. In support of this thesis, milk stored at -10 degrees C had a concentration of 18.7 mM free fatty acids compared with only 1.1 mM in an identical sample stored at -70 degrees C.