[Observation on the afferent nerve activity induced by stimulation of renal receptors in the rabbits]

The effects of stimulation of renal mechano- and chemoreceptors on the afferent renal nerve activity (ARNA) were observed in 44 anesthetized rabbits. The results obtained were as follows: (1) Elevation of ureteral pressure (UP) could induce an increase in integral value of ARNA by 175.13 +/- 22.41% (P less than 0.001). (2) KCl (0.15 mol/L) and NaCl (1 mol/L) perfused retrogradely into pelvis via ureter route resulted in increase of integral value of ARNA by 253.79 +/- 21.64% and 172.17 +/- 15.19% (P less than 0.001), respectively. (3) Four patterns of afferent unit discharge were found: no spontaneous activity, regular spontaneous activity, regular spontaneous activity with burst and irregular spontaneous activity. (4) The units of afferent renal nerve with no spontaneous activity were activated markedly by elevation of UP, while the units with spontaneous activity showed no change. (5) In response to the retrograde perfusion of KCl (0.15 mol/L) and NaCl (1 mol/L) into pelvis, the activity in units with spontaneous discharge increased markedly by 210.70 +/- 23.40% and 140.07 +/- 15.72% (P less than 0.001), respectively, and the other units may be recruited concomitantly. (6) The units with no spontaneous discharge were activated by renal artery occlusion. The results implied that there are mechanoreceptor, R1 and R2 chemoreceptors in the kidney of the rabbit, and they may sense the change in UP, renal ischemia and ionic (K+, Na+) concentration of the solute within pelvis.

[Hemodynamic effects of renal interoreceptor and afferent nerve stimulation in rabbit]

Hemodynamic effects of renal mechano- and chemoreceptor activation and afferent renal nerve stimulation were observed in 39 anesthetized rabbits. The mean arterial pressure (MAP) and heart rate (HR) were decreased following elevation of ureteral pressure (13-22 mmHg), and retrograde perfusion of NaCl (1.0 mol/L) or KCl (0.15 mol/L) into pelvis via ureter route. The decrease in MAP was enhanced by sinoaortic denervation. HR, MAP, mesentery arterial perfusion pressure (MPP), hindlimb arterial perfusion pressure (HLPP), left ventricular pressure (LVP), left ventricular dp/dtmax (LV dp/dtmax), cardiac output (CO) and total peripheral resistance (TPR) were decreased during electrical stimulation of afferent renal nerve. By sinoaortic denervation, the aforementioned hemodynamic parameters, except HR, CO and TPR, were reduced more markedly by electric stimulation of afferent renal nerves. Therefore it appears that sinoaortic depressor reflex plays a buffer role in the cardiovascular responses to the stimulation of afferent renal nerves.

Development of a tooth germ within an autogenous clavicular graft

The left side of the mandible distal to the second primary molar of a 3 years old Southern Chinese boy was resected as a result of osteomyelitis. A diaphyseal clavicular graft pedicled on the sternomastoid muscle was selected for the reconstruction of the mandible. By the age of 6 years, the mandible although stunted in size did exhibit appropriate remodelling. In addition a tooth germ in the region of the second permanent molar was found developing in the autogenous bone graft of the mandible.

Immunoradiometric assay with use of magnetizable particles: measurement of thyrotropin in blood spots, to screen for neonatal hypothyroidism

We adapted a commercial immunoradiometric assay (IRMA) to measure thyrotropin in filter-paper blood spots. Two 3-mm blood spots are used for each standard and sample. These are incubated for 2 h with radiolabeled antibody and for 30 min with magnetic antibody, followed by a 10-min separation procedure. Assay sensitivity is 6 milli-int. units/L. Coefficients of variation (precision profile of the standard curve) ranged from 4.3 to 9.6%. The coefficient of correlation (r) between thyrotropin concentrations in the blood spots and in serum was 0.93. Pre-elution of the blood spots is necessary for short incubation time. Short incubation time, little need for specialized equipment, the high precision and sensitivity characteristic of IRMA, and ease of collection, transport, and storage of the blood-spot samples make this assay suitable for neonatal hypothyroid screening.

Immunoradiometric assay with use of magnetizable particles: measurement of thyrotropin in blood spots, to screen for neonatal hypothyroidism

We adapted a commercial immunoradiometric assay (IRMA) to measure thyrotropin in filter-paper blood spots. Two 3-mm blood spots are used for each standard and sample. These are incubated for 2 h with radiolabeled antibody and for 30 min with magnetic antibody, followed by a 10-min separation procedure. Assay sensitivity is 6 milli-int. units/L. Coefficients of variation (precision profile of the standard curve) ranged from 4.3 to 9.6%. The coefficient of correlation (r) between thyrotropin concentrations in the blood spots and in serum was 0.93. Pre-elution of the blood spots is necessary for short incubation time. Short incubation time, little need for specialized equipment, the high precision and sensitivity characteristic of IRMA, and ease of collection, transport, and storage of the blood-spot samples make this assay suitable for neonatal hypothyroid screening.

Binding characteristics of thyroxin binding globulin in serum of normal, pregnant, and severely ill euthyroid patients

Serum from normal, pregnant, and severely ill patients was stripped of endogenous thyroid hormones and diluted 1100-fold in barbital buffer. We then used it to study the binding characteristics of thyroxin binding globulin (TBG), noting significant differences in binding capacities among the groups. The mean (+/- SD) triiodothyronine/thyroxin ratio for binding capacity was 18 +/- 4 for normal subjects. The ratio was significantly increased in pregnant patients, 21 +/- 4 (p less than 0.05), and significantly lower in severely ill patients, 12 +/- 4 (p less than 0.05). When serum was diluted before assay, to give a uniform TBG concentration among groups, these apparent differences in binding characteristics were eliminated. It therefore is unlikely that different molecular species of TBG account for the variations in binding characteristics in these clinical states. Apparently, the distribution of thyroxin and triiodothyronine among the binding sites on TBG changes with variations in TBG concentration. This may explain the discrepancies observed in the concentrations of free thyroid hormones as estimated by various methodologies.

Binding characteristics of thyroxin binding globulin in serum of normal, pregnant, and severely ill euthyroid patients

Serum from normal, pregnant, and severely ill patients was stripped of endogenous thyroid hormones and diluted 1100-fold in barbital buffer. We then used it to study the binding characteristics of thyroxin binding globulin (TBG), noting significant differences in binding capacities among the groups. The mean (+/- SD) triiodothyronine/thyroxin ratio for binding capacity was 18 +/- 4 for normal subjects. The ratio was significantly increased in pregnant patients, 21 +/- 4 (p less than 0.05), and significantly lower in severely ill patients, 12 +/- 4 (p less than 0.05). When serum was diluted before assay, to give a uniform TBG concentration among groups, these apparent differences in binding characteristics were eliminated. It therefore is unlikely that different molecular species of TBG account for the variations in binding characteristics in these clinical states. Apparently, the distribution of thyroxin and triiodothyronine among the binding sites on TBG changes with variations in TBG concentration. This may explain the discrepancies observed in the concentrations of free thyroid hormones as estimated by various methodologies.

Diagnostic value of thyrotropin concentrations in serum as measured by a sensitive immunoradiometric assay

A new, highly sensitive immunoradiometric thyrotropin (TSH) assay involving solid-phase-coupled monoclonal antibodies (Boots-Celltech Sucrosep IRMA-TSH) has been evaluated in a wide variety of patients with thyroidal and nonthyroidal illnesses and the results compared with those obtained by conventional diagnostic TSH RIAs. The sensitivity of the present assay ranged from 0.036 to 0.1 milli-int. unit/L (mean 0.056). TSH, measurable in serum of each of 128 euthyroid patients, ranged from 0.1 to 6.3 milli-int. units/L (mean 1.7, SD 1.1). Similar concentrations were found in 15 healthy pregnant women. TSH was undetectable in 27 hyperthyroid patients, of whom six were tested with thyroliberin stimulation and failed to respond. The mean TSH concentration measured in 62 seriously ill hospital patients of 2.7 (SD 2.5) milli-int. units/L was significantly higher (p less than 0.05) than in the euthyroid patients. Basal values and peak TSH responses to thyroliberin testing correlated well (r = 0.63, n = 48), irrespective of clinical diagnosis. We conclude that the present assay readily discriminates between euthyroid and hyperthyroid patients and should replace conventional TSH RIAs in diagnostic laboratories.

Diagnostic value of thyrotropin concentrations in serum as measured by a sensitive immunoradiometric assay

A new, highly sensitive immunoradiometric thyrotropin (TSH) assay involving solid-phase-coupled monoclonal antibodies (Boots-Celltech Sucrosep IRMA-TSH) has been evaluated in a wide variety of patients with thyroidal and nonthyroidal illnesses and the results compared with those obtained by conventional diagnostic TSH RIAs. The sensitivity of the present assay ranged from 0.036 to 0.1 milli-int. unit/L (mean 0.056). TSH, measurable in serum of each of 128 euthyroid patients, ranged from 0.1 to 6.3 milli-int. units/L (mean 1.7, SD 1.1). Similar concentrations were found in 15 healthy pregnant women. TSH was undetectable in 27 hyperthyroid patients, of whom six were tested with thyroliberin stimulation and failed to respond. The mean TSH concentration measured in 62 seriously ill hospital patients of 2.7 (SD 2.5) milli-int. units/L was significantly higher (p less than 0.05) than in the euthyroid patients. Basal values and peak TSH responses to thyroliberin testing correlated well (r = 0.63, n = 48), irrespective of clinical diagnosis. We conclude that the present assay readily discriminates between euthyroid and hyperthyroid patients and should replace conventional TSH RIAs in diagnostic laboratories.

Bilateral, asymmetrical, complete oroocular facial clefts and supernumerary teeth in a young Chinese female

The clefting in this case involved the face and alveolar processes. The supernumerary teeth were associated with the clefts and situated mesially of the cleft on the left side and distally on the right.