Biomedical subjects
Publications and source records attributed to T Mayer.
Provider evaluation of HMO contracts is a complicated process. The issues are best examined by separating the process into financial, administrative, marketing, and provider relationship areas. Team negotiating by the provider group is a tactic that is effective in dealing with complex risk factors, reinsurance, pharmacy, pools, carve-outs, and nonfinancial enhancements.
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The modified Schöber technique, a method for assessing lumbar spine flexion, was subjected to an analysis of reliability. Fifty normal subjects (21 men, 29 women) were evaluated for lumbar flexion mobility using a blind inter-rater "worst case" protocol. Simultaneously, other sources of error affecting test reliability, such as presence of dimples of Venus, relationship of skin distraction to movement of underlying structures, and upper level of Schöber skin landmarks were also considered. Analysis suggested that systematic error can be introduced that adversely affects inter-rater reliability (r = 0.71). Moreover, skin landmarks are inconsistently present, being completely absent in 26% of cases. Skin tends to distract even over completely immobile bony structures (eg, the sacrum), whereas, on average, only 3.5 of the 6 spinal segments (T12-S1) are included in the Schöber technique for purported measurement of "lumbar spine flexion." The utility of this method is questioned on both scientific and clinical grounds.
Formerly, stress-fractures of the metatarsus were the most common stress fractures. But over the last years, tibial and calcaneal localizations have dominated. The diagnosis of a calcaneal stress fracture is usually easy, provided the possibility is remembered. The symptoms are indeed vague, and radiological alterations are often not seen during the first 2 months. Sclerosis (callus formation) is the first finding on roentgenograms. A periosteal reaction like on tabular bone is never seen. Signs of a stress fracture are first seen on bone-scan, but other nonstress-related bone abnormalities which have not manifested any radiographic changes such as early osteomyelitis, fibrous dysplasia, bone tumor, etc. have to be excluded. The treatment is simple. Vigorous activities are stopped for 6 weeks, soft heel pads are given, partial weight-bearing can be helpful for some days. Plaster is usually neither necessary nor useful.
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To define epitopes of tetanus toxin, we compared four different in vitro systems in terms of their ability to produce tetanus toxin-specific subfragments from cloned DNA. A transcription-translation system developed from a nontoxigenic strain of Clostridium tetani was found to yield predominantly full-sized peptides. Such peptides were used to map six different epitopes for eight monoclonal antibodies. The toxin-neutralizing properties of the antibodies were determined in an in vitro assay, based on the toxin-mediated inhibition of norepinephrine release from rat brain particles. Two monoclonal antibodies recognizing epitopes within the regions Ser-744 to Ser-864 and Ile-1224 to Asp-1315 could neutralize the toxin. A third nonneutralizing antibody was shown to recognize the synthetic peptide Phe-947 to Glu-967 derived from the tetanus toxin sequence. This peptide contains a human T-cell epitope.
The E1-glycoprotein (Mr = 26,014; 228 amino acids) of mouse hepatitis virus A59 is a class III membrane glycoprotein which has been used in this study as a model system in the study of membrane integration and protein transport. The protein lacks an NH2-terminal cleavable signal sequence and spans the viral membrane three times. Hydrophobic domains I and III could serve as signal sequences for cotranslational membrane integration. Domain I alone was sufficient to translocate the hydrophilic NH2 terminus of E1 across the membranes as evidenced by glycosylation of a newly introduced N-glycosylation site. The COOH-terminal part of E1 involving amino acids Leu124 to Thr228 was found to associate tightly with membranes at the post-translational level, although this part of the molecule lacks pronounced hydrophobic sequences. Membrane protection assays with proteinase K showed that a 2-kDa hydrophilic fragment was removed from the COOH terminus of E1 indicating that the protein is largely embedded into the membrane. Microinjection of in vitro transcribed capped and polyadenylated mRNA into CV-1 cells or into secretory AtT20 pituitary tumor cells showed that the E1-protein accumulated in the Golgi but was not detectable at the plasma membrane or in secretory granules. The 28 NH2-terminal hydrophilic amino acid residues play no role in membrane assembly or in intracellular targeting. Various NH2-terminal portions of E1 were fused to Ile145 of the cytoplasmic N-protein of mouse hepatitis virus. The resulting hybrid proteins were shown to assemble into membranes in vitro and were detected either in the rough endoplasmic reticulum or transient vesicles of microinjected cells.
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A derivation is given for the dependence of the rate constant of the reaction of OH radicals with a spherical macromolecule on the rate by which such radicals are scavenged by the medium. Experiments were carried out with oxygenated solutions of dilute single-stranded phi X174 DNA at 10(-4)M NaCl (large reaction radius of DNA) or at 10(-4)M NaCl + MgCl2 (small reaction radius) with t-butanol as a scavenger. The results of these experiments cannot be described by simple second-order competition, but can be explained by the predicted dependence of the rate constant of the reaction OH + DNA on the concentration of t-butanol. Furthermore, the results show that only part of the reactions of OH radicals with phi X174 DNA leads to DNA inactivation, and that even at zero scavenger concentration OH radicals are scavenged by other molecules than DNA, presumably impurities remaining even after careful purification of the DNA.
21 patients with stiffness of the knee were operated on, for mobilisation under epidural analgesia. As soon as the patients returned to the ward the leg was placed on a mobilisation-splint driven by an electric motor. Epidural analgesia was continued by infusion of 0.25 ml/kg . h of 0.125% bupivacaine via epidural catheter for a period of four to six days whereafter the catheter was removed. Analgesia during mobilisation was complete or almost complete in 15 patients. In 5 cases loss of sensitivity was present predominantly or selectively in the contralateral extremity, in one patient segmental extension of epidural analgesia did not include the knee. The bladder had to be catheterized in 9 patients, three suffered from decubital ulcers which disappeared after removal of the epidural catheter. In spite of the frequency of side effects, which can be diminished by further experience, continuous epidural analgesia is advantageous for early mobilisation of the knee after arthrolysis. The patients must be informed about side effects and possible complications before giving their consent for this method of long lasting analgesia.
In a 3-year period of prospective study, 250 pediatric patients with multiple trauma (injury to at least two body areas) had injuries scored by a modification of the Injury Severity Scale (MISS). This scale uses the categories and rankings of the Abbreviated Injury Scale-1980 (AIS-80) except for neurologic injuries. Neurologic injuries are scored by using a combination of the Glasgow Coma Scale (GCS) and other neurologic findings (presence of surgical mass lesion, pupillary light response, and oculocephalic reflexes). The MISS is calculated as the sum of the squares of the three most severely injured body areas. The mean MISS score was 27.8, with 38% of MISS scores greater than or equal to 25 and 62% less than 25. Among those with MISS scores greater than or equal to 25 there was a 40% mortality and 30% disability, while there were no mortalities and 1% disability for those with MISS scores less than 25 (p less than 0.001). Overall mortality was 15%, with 10% disability. Mean MISS scores for death and disability were 33.4 and 30.2, respectively. Neurologic injuries were present in 173 patients (69%); 128 patients had severe head injuries (coma greater than 6 hours duration); 80% of all deaths were due to neurologic injury and all but two deaths had some degree of head injury; the remaining 20% of deaths were due to chest and abdominal injuries. Patients with MISS grade 5 injury (critical, survival uncertain) had 73% mortality, while those with grades 4 and 3 injury had 8% and 2% mortality, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
In a 5-year period of prospective study, 369 pediatric patients with multiple trauma (injury to at least two body areas) had injuries scored by a Modification of Injury Severity Scale (MISS). This scale uses the categories and rankings of the Abbreviated Injury Scale-1980 (AIS-80) except that the classification of neurological injuries are scored by the Glasgow Coma Scale (GCS) and other neurological findings (presence of a surgical mass lesion, pupillary light response, and oculocephalic reflexes). The MISS is calculated as the sum of the squares of the three most severely injured body areas. The mean MISS score was 23.8 with 33% of MISS scores greater than 25 and 67% less than 25. Among those with MISS scores greater than 25 there was a 44% mortality and 31% disability. In the group with MISS scores less than 25, there were no mortalities, and a 1% disability (p less than 0.001). Overall mortality was 14% with 9% disability. Mean MISS scores for death and disability were 35.1 and 29.6, respectively. Neurologic injuries were present in 274 patients (74%). 163 patients had severe head injury (coma greater than 6 h duration). 86% of all deaths were due to head injury and all but 2 deaths had some degree of head injury. The remaining 14% of deaths were due to chest and abdominal injuries. Patients with MISS grade 5 injury (critical, survival uncertain) had 74% mortality, while those with grades 4 and 3 injury had 8 and 1.5% mortality. In a comparison with pediatric patients with head injury only (coma greater than 6 h, no multiple trauma) there was found to be a 12% mortality in the head injury only group versus a 33% mortality in the multiple trauma plus head injury group. The MISS serves as an accurate predictor of morbidity and mortality in pediatric trauma. The best predictors of outcome were a MISS less than 25 and the degree of neurological injury.
Recent evidence suggests that HLA-A,B antigens present on human platelets, are acquired from plasma. Using hypertonic acid chloroquine (200 mg/ml, pH 5.0, 1 hr, 4 degrees C), we demonstrate elution of most or all HLA-A2 and HLA-B7,40 immunoreactive material from platelets. Corresponding antigens on human lymphocytes were not affected by this treatment. These findings are consistent with the hypothesis that HLA-A,B antigens are adsorbed onto platelet surfaces.
The glutamate dehydrogenase activity found in the serum of patients with Reye's syndrome is shown to be inhibited about 1000-fold more potently by GTP than is the normal human enzyme. 1 mM ADP, which with the normal enzyme effectively reverses GTP inhibition, has no effect in the GTP inhibition of the Reye's syndrome serum activity.
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A 3-week-old child with respiratory distress had an air-fluid level on chest roentgenogram. Computed tomography of the chest distinguished the mass as a discrete lung abscess, without underlying abnormality. Due to failure of the child's condition to improve with medical therapy, a limited thoracotomy and drainage of the lung abscess was performed; Escherichia coli and no anaerobic organisms grew from cultures of abscess material. We believe computed tomography to be of great benefit in defining suspected lung abscess in the neonate.