Immunochemiluminometric and immunoradiometric determinations of intact and total immunoreactive parathyrin: performance in the differential diagnosis of hypercalcemia and hypoparathyroidism

Parathyrin (parathyroid hormone; PTH) was measured with three immunoassays: a two-site immunochemiluminometric (ICMA) and a two-site immunoradiometric (IRMA) method for intact PTH, and a sensitive radioimmunoassay for mid-region or "total" PTH, measuring both intact hormone and inactive fragments. Single specimens from normal subjects and from individuals with primary hyperparathyroidism, hypercalcemia associated with malignancy, and hypoparathyroidism were analyzed with all three methods. All individuals with primary hyperparathyroidism showed absolutely above-normal concentrations with the mid-region RIA, 28 of 29 did with the ICMA, and 21 of 29 did with the IRMA. PTH concentrations in primary hyperparathyroidism were most increased relative to normal subjects with the mid-region assay (10.4 times), less so with the intact assays (ICMA 5.5 times; IRMA 5.3 times). Concentrations of intact PTH were suppressed below normal in nearly all patients with hypercalcemia associated with malignancy, as measured with the ICMA (26 of 30) and the IRMA (28 of 30) assays. In marked contrast, results for mid-region PTH were normal or slightly above normal, consistent with studies suggesting that the parathyroids secrete both intact hormone and inactive fragments, the former being more sensitive to suppression by hypercalcemia. In hypoparathyroidism PTH concentrations were detectable but below normal in all patients by the intact assays and in all but one patient by the mid-region assay. These low concentrations are probably due to a nonspecific serum effect that could be resolved with selection of a more appropriate standard matrix. Although all three assays are useful in the differential diagnosis of hypercalcemia, two-site intact assays are more convenient and more specific in patients with compromised renal function.

[Miliary tuberculosis in adults. Study of 67 patients]

67 patients with miliary TB diagnosed over a 15 year period (1973-1987) have been retrospectively studied. The clinical and analysis data were evaluated, highlighting different factors associated to higher mortality. 53 patients diagnoses were made premortem and 14 had the diagnosis made post-mortem. The age of the patients was of 48 +/- 21 (mean +/- DE) years, inferior to other series, this showing a higher prevalence and early age of infection in the area. 63% had miliary radiological features; the most frequent tests performed were liver biopsy with profitability of 80% and bronchoscopy which, together with transbronchial biopsy and bacterial analysis of the bronchoalveolar lavage, showed a positive diagnosis of 60%. The factors which were associated with bad prognosis were cavitated or chronic lesions (P less than 0.01), chronic diseases and immunosuppression factors associated, this not being statistically significant.

[Incipient carious lesions and their histological characteristics, in teeth of Mexico city residents]

Twelve tooth sections from young Mexico City patients with incipient caries-like lesions, were examined through polarized light microscope and lightening media. According to size, lesions under study were classified as "late" in occurrence. Their median depth was 450 microns: their surface area measured an average breadth of 63 microns; the body of the lesion was 310 microns, and the dark zone, 73 microns. The translucid area was detected in 83% of the sections. In 41% of the teeth, well-mineralized laminations were observed within the body of the lesion. Further studies on a larger number of cases is vehemently recommended, in order to understand better the characteristics and variations of incipient and latent lesions in our general population.

Measurement of parathyroid hormone

Interpretation of serum immunoreactive PTH measurements requires an understanding of the secretion, metabolism, and heterogeneity of circulating immunoreactive PTH. Both intact hormone and biologically inactive carboxyl fragments containing the middle and C-terminal regions are secreted by the parathyroid glands. Inactive fragments also are produced peripherally by metabolism of intact hormone by liver and kidney. Inactive fragments represent 75 to 95% of the total immunoreactivity in serum, a consequence of their long half-life in vivo as compared with intact hormone. Immunoassays for PTH can be divided into those measuring intact hormone (N-terminal, intact) and those measuring both inactive fragments and intact hormone (mid-region, C-terminal, polyvalent). The latter principally measures inactive fragments because of their greater concentration as compared with intact hormone in peripheral serum. The clinical utility of PTH assays varies considerably because of differences in their specificity and sensitivity. Serum PTH levels have been more often observed to be elevated in individuals with primary hyperparathyroidism with the use of research quality radioimmunoassays that recognize both inactive fragments and intact hormone than with conventional N-terminal or intact assays. Homologous mid-region assays have provided exceptional clinical sensitivity in confirming primary hyperparathyroidism. Comparison of a sensitive mid-region radioimmunoassay with a recently developed two-site, noncompetitive chemiluminescent immunoassay for intact PTH indicated that both methods were highly useful in the differential diagnosis of hypercalcemia. The mid-region assay provided the best diagnostic sensitivity in primary hyperparathyroidism with more elevated levels of PTH. The sensitivity of the intact assay was good, a significant improvement over conventional N-terminal and intact assays. The specificity of the intact assay was clearly superior, with measured PTH levels found to be suppressed to below normal in most subjects with hypercalcemia associated with malignancy. In contrast, measured levels were primarily normal with the mid-region assay. The higher levels of immunoreactive PTH observed in nonparathyroid hypercalcemia with the mid-region assay are in agreement with the measurement of biologically inactive carboxyl fragments, which continue to be secreted in hypercalcemia.

Dental caries status of young children in a suburban community of Mexico City

One hundred and thirty-four children, 6 to 7 yr of age from a public school in Tepepan, Mexico were examined for the prevalence and severity of dental caries. Average deft score was 6.08 and defs was 12.15. Average DMFT and DMFS scores were .57 and .99 respectively. It was observed that 66% of primary teeth with carious lesions required one surface restoration and 11% three or more surface restorations. In the permanent dentition 99% of the affected teeth required one surface restoration. A comparison of the results with those of the Mexico City public school children survey (1980) showed that the Tepepan children had a similar caries level in primary teeth and a lower caries level in permanent teeth. Although the Tepepan group showed fewer carious lesions, their caries index and unmet restorative index are still high, especially for primary dentition, so an intensive educational, preventive and restorative program is required.

Carbonic anhydrase is aberrantly and constitutively expressed in both human and murine erythroleukemia cells

The levels of the erythrocyte proteins carbonic anhydrase (CA) and hemoglobin (Hb) change coordinately during human ontogeny. To further probe the coordinate gene expression of these two proteins in vitro, we used an immunoblotting technique to measure their levels during erythroid differentiation in normal human and murine erythroid progenitors, in human and murine erythroleukemia cells, and in normal murine erythroid progenitors infected with Friend virus. Levels of CA and Hb seem to gradually increase in normal differentiating stem cells. In contrast, both human and murine erythroleukemia cells show high levels of CA, but not of Hb, prior to induction of differentiation. Friend virus infection of normal murine progenitors appears to stimulate CA synthesis as an initial and integral step in transformation. In addition, both the erythroleukemia cells and the erythroid progenitors transformed with Friend virus seem to contain much higher levels of CA than Hb during the early stages of differentiation. This relationship is in marked contrast to normal erythroid differentiation, in which Hb levels are always higher than CA levels. Thus, neoplastic transformation seems to be associated with aberrant production of CA that does not correspond to a maturation arrest of the normal differentiation sequence.

Intrapulmonary shunting during deliberate hypotension with nifedipine, diltiazem and labetalol in dogs

Pulmonary shunt (Qs/Qt) was calculated in 49 mongrel dogs weighing 18-20 kg during mechanical ventilation, before and during deliberate hypotension with either nifedipine (group N), diltiazem (group D), labetalol (group L), or ethyl alcohol and polyethylene glycol (group E). A 30 per cent decrease in mean arterial blood pressure occurred after two minutes of nifedipine infusion, two minutes after diltiazem, and three minutes after labetalol; these effects lasted two hours after nifedipine administration, 90 minutes after diltiazem and three hours after labetalol. There was an accompanying significant decrease in systemic and pulmonary vascular resistance. Qs/Qt and cardiac output increased significantly after nifedipine infusion. Shunt increased (mean +/- S.E.) from 9.7 +/- 0.8 to 18.25 +/- 1.05 per cent at two minutes (p less than 0.0005); 19.05 +/- 1.2 per cent at 30 minutes (p less than 0.005); 17.5 +/- 1.6 per cent at two hours (p less than 0.01); and 12 +/- 1.1 per cent at three hours (p less than 0.025). No increase in shunt occurred after the administration of diltiazem, labetalol or polyethylene glycol and ethyl alcohol. Arterial oxygen tension (PaO2) decreased significantly after nifedipine infusion from 146 +/- 11.5 to 105 +/- 3.5 mmHg two minutes after infusion; to 89.5 +/- 3 mmHg 30 minutes after; 115 +/- 4.75 mmHg two hours after; and 130 +/- 10.75 mmHg three hours later. PaO2 was not significantly different after diltiazem, labetalol, or polyethylene glycol and ethyl alcohol administration. With nifedipine cardiac output increased from 2.25 +/- 0.3 to 3.95 +/- 0.25 after two minutes (p less than 0.005) to 3.85 +/- 0.35 after 30 minutes (p less than 0.005), 3.7 +/- 3 after two hours (p less than 0.01) to 2.9 +/- 1.1 after three hours. No significant increase in cardiac output occurred in groups D or L. These results suggest that only nifedipine infusion significantly alters oxygenation in dogs and therefore its use warrants caution in the presence of a preexisting abnormal Qs/Qt.

Level of consciousness after cadaveric kidney transplant under halothane anaesthesia

Serum and urine bromide levels, serum morphine levels, and postoperative awakening times were observed in 24 patients; 16 undergoing cadaveric kidney transplantation under halothane anaesthesia, eight without preanaesthetic medication (Group A) and eight with morphine preanaesthetic medication (Group B), and eight patients (control) with normal kidney function scheduled for colon resection (Group C). Bromide levels were higher in patients after kidney transplant than in the control group. Transplant patients who did not receive morphine awakened faster after anaesthesia than patients who received 10 mg of morphine 60 minutes before anaesthesia. Morphine levels at the end of anaesthesia were 145 micrograms X 100 ml-1 in Group B; significantly higher than those found in patients with normal kidney function (Group C) (5 +/- 1.05). The majority of the patients undergoing kidney transplantation and receiving morphine for premedication were fully awake 24 hours following surgery despite serum bromide levels of 158 micrograms X ml-1. Control patients had higher awakening scores after surgery than patients in Group A, despite receiving 10 mg of morphine as preoperative medication. Serum bromide levels were far below 480 micrograms X ml-1, the level required to produce clinical symptoms of bromism. The serum and urine bromide levels found in the patients after kidney transplant, even when higher than the control group, were not high enough to explain the prolonged sleepiness found in these patients. The morphine given as preoperative medication may be one of the factors responsible for this finding.(ABSTRACT TRUNCATED AT 250 WORDS)

A new radiological technique in evaluation of prosthetic fitting

Xeroradiography is an excellent technique in evaluating the fit of extremity prostheses. Because of its inherent characteristics, xeroradiography can clearly demonstrate the stump-socket relationship. Consequently, the degree of contact achieved and attendant pressure problems, if any, can be precisely determined.

Orthosis to correct shoulder pain and deformity after trapezius palsy

An orthosis is described which provides the following benefits to patients with trapezius paralysis: (1) Cosmetically, appearance is improved because the orthosis restores the shoulder to its normal position. (2) Pain is alleviated or minimized by relieving the pull against the levator scapulae and the rhomboideus muscles. (3) Endurance is improved allowing the patient to return to previous employment and full activities.

Typing for MLC determinants using lymphocytes from cousin-marriage offspring as typing cells

A first cousin marriage family with three children was studied. One sibling (AW) was homozygous for W32.W10. When used as stimulator in one way MLC, AW elicited a very low response in family members possessing this haplotype. Serologically identical sibling and father combination showed bidirectional non-stimulation in one way MLC. Therefore, AW is assumed to be homozygous not only for SD antigens, but also for LD determinants which we call LD W10a. Among the 43 unrelated individuals tested with AW, an association between LD W10a and W10 antigen of the second HL-A locus was observed. Of 12 W10 positive individuals tested, five carry this allele as compared to one out of 31 W10 negative individuals. The data suggest a strong linkage disequilibrium between the FOUR locus determinant W10 and LD determinant LD W10a.