An assessment of test criteria for evaluating the performance and integrity of sterilizing filters

Measurements of serum calcitonin (iCT) were performed in 300 relatives of 43 Norwegian patients with medullary thyroid carcinoma (MCT). Prior to the screening, familial occurrence of the disease was known in only one of the families. Persistant hypercalcitoninemia (serum levels greater than 0.50 ng/ml) was demonstrated in 2 healthy persons from this family and in 3 first degree relatives of 2 patients with apparently sporadic disease. Additional 7 relatives of 5 other "sporadic" cases showed elevation of serum iCT on one occasion, while later controls revealed normal values. Twenty persons had high normal serum levels (0.35 ng/ml less than or equal to iCT less than 0.50 ng/ml). The significance of transitory hypercalcitoninemia and high normal values are at the present unknown, but these persons will have further tests. Stimulation tests for iCT secretion were found to be of limited value in distinguishing between normal and pathological serum iCT. All individuals found to have chronic hypercalcitoninemia belonged to families in which the probands showed one or several of the following "high risk" factors: A positive history of thyroid disease, early age of onset, bilateral presence of the thyroid tumour, association with other endocrine or peripheral neurogenic tumours, and marphanoid habitus. The iCT screening was however negative in the relatives of the two probands revealing 4 and 5 of these factors. Since neither the family history nor the presence or absence of "high risk" factors distinguished between sporadic and familial cases, it is concluded that serum iCT measurements should be carried out in primary relatives of all patients with MCT.     

The early detection of colorectal cancer

A review of the American Cancer Society's statistics for colorectal cancer indicates that there has been little improvements in the survival rate for this disease in the past 25 years. Although there have been advances in surgical techniques, radiation therapy, and chemotherapy, the key to improved survival rates is earlier diagnosis. A significant percentage of patients continues to present with regional or distal metastasis at the time of their initial diagnosis. Both proctosigmoidoscopy and guaiac impregnated filter slide paper methods have been productive in diagnosing this disease at an earlier stage. The "Hemoccult" test, however, is inexpensive, can be used on a routine basis, is easier for patients to perform themselves, and is aesthetically pleasing. It represents a significant cost savings compared to proctosigmoidoscopy and should be advocated for routine use in all patients over 40 years of age. Although there continues to be a role for local and regional mass screening programs, significant improvements in colorectal survival rates cannot be expected until routine application of this type of screening is practiced.     

Systemic lupus erythematosus in children: the complex problems of diagnosis and treatment encountered in 101 such patients at the Mayo Clinic

Between 1945 and 1970, 101 children (86 girls and 15 boys) with systemic lupus erythematosus were evaluated at the Mayo Clinic. Only 9 children were less than 9 years old at the time of diagnosis. The most frequent presenting complaint was arthralgia; fever, fatigue, and a "butterfly" malar rash also were common. Renal involvement, found in more than 76 per cent of patients, was a prognostically poor sign. The overall survival of children with renal involvement is improved by the use of adequate steroid therapy.     

Imported measles. A potential control problem

From Dec 23, 1978, through Jan 31, 1979, an outbreak of five laboratory-confirmed cases and four clinical cases of measles occurred in a Vietnamese refugee population living in a single housing complex in Albuquerque, NM. The index cases were in two refugee siblings in whom measles was incubating on arrival in the United States. Despite spread through three subsequent generations of disease transmission within the Vietnamese population, there was no additional spread into the general Albuquerque population. Responsible factors included the age distribution of susceptible persons, the social isolation of the refugee population, and the physical structure of the housing complex. There is a need to identify the problem of imported measles in "ethnic islands" in need of vaccination.     

Haemoglobins of the shark, Heterodontus portusjacksoni II. Amino acid sequence of the alpha-chain

The amino acid sequence of the alpha-chain of the principal haemoglobin from the shark, H. portusjacksoni has been determined. The chain has 148 residues and is acetylated at the amino terminal. The soluble peptides obtained by tryptic and chymotryptic digestion of the protein or its cyanogen bromide fragments were isolated by gel filtration, paper ionophoresis and paper chromatography. The amino acid sequences were determined by the dansyl-Edman procedure. The insoluble "core" peptide from the tryptic digestion contained 34 residues and required cleavage by several prosteases before the sequence was established. Compared with human alpha-chain there are 88 amino acid differences including the additional seven residues which appear on the amino terminal of the shark chain. There is also one deletion and one insertion. The chain contains no tryptophan but has four cysteinyl residues which is the highest number of such residues recorded for a vertebrate globin. In the alpha1beta1 contact sites there are four changes in the oxyhaemoglobin form and six deoxy form. Nine of the 16, alpha1beta1 contact sites show variation while three of the haem contact sites have changed in comparison to the residues known to be involved in these interactions in horse haemoglobin alpha-chain. Use of the sequence data to estimate a time of divergence of the shark from the main vertebrate line yielded the value of 410 +/- 46 million years. The data, in general, support the palaeontological view that bony fishes arose before the elasmobranchs.     

The relationship of education to blood pressure: findings on 40,000 employed Chicagoans

The relationship of education to both actual blood pressure and the prevalence of high blood pressure, based on a systolic pressure of 160 mm Hg or greater or a diastolic pressure of 95 mm Hg or greater, was analyzed among 27,033 men and women, white and black, age 25-44 and 45-64, from the Chicago Heart Association Detection Project in Industry. The educational status of each individual was categorized as not a high school graduate, high school graduate, some college, or college graduate. A statistically significant inverse association between education and high blood pressure was present in all groups of whites. This association could not be "accounted for" by differences in age, relative weight, and heart rate among the educational strata. Controlling for these variables did, however, lessen the association. Among black males a significant inverse association between education level and blood pressure was found for the younger group. For the older black males there was a clear inverse association although with the small numbers it did not achieve statistical significance. For black females there was no clear association.     

Performance analysis of a CDMA network with fixed overlapping sectors in nonuniform angular traffic

The problem of base station antenna assignment (BSAA) with minimum mobile transmit power (MTP) is studied for CDMA networks with fixed overlapping sector antenna architecture (FOSAA) where more than one co-located antenna is used to cover any space in the network. It is first noted that the non-FOSAA has limitations in switching users between in-cell sectors and also out-of-cell sectors in moderately-loaded networks. It is then shown that by employing overlapping sectors in FOSAA, we can exploit the flexibility of assigning a user to one of possibly many potential antenna to effectively support the nonuniform azimuthal traffic. It is also shown that the BSAA problem with minimum MTP is a special case of a general problem that was solved by Hanly and Yates. The process of dynamic cell sectoring is differentiated twofold as cell-breathing (CB) and cell-slicing (CS) and the latter can be viewed as being azimuthal discrete counterpart of the former radial scheme. The hybrid scheme, CB+CS, offers better performance in terms of minimum total MTP in a FOSAA system. Simulation results demonstrate the flexibility and effectiveness of the FOSAA system in nonuniform angular traffic.     

A reconfigurable high-frequency phase-locked loop

Reconfigurable phase-locked loops (PLLs) present the advantage of fast-frequency acquisition combined with narrow-noise bandwidth, since their parameters can be dynamically adjusted. High-frequency PLLs are generally implemented by means of analog circuits which are not easily reconfigured during operation. However, the five-port technique allows the discrimination of the phase difference between two microwave signals using a mixed circuit. In this paper the design of a PLL comprising a five-port based phase detector is presented. This system benefits from the phase-detector digital circuit to carry out the loop filtering. Simulation results for different conditions of noise and frequency acquisition are shown. We also present measurement results to confirm the simulations.