Cerebrospinal fluid vasopressin as a marker of central nervous system metastases from small-cell bronchogenic carcinoma

Vasopressin (ADH) was measured in CSF and plasma in 75 evaluable patients with known or suspected CNS metastases from small-cell bronchogenic carcinoma (SCBC), and in 66 control patients having neither malignant disease nor organic CNS disease. The presence of CNS metastases was confirmed or excluded on the basis of computed tomographic scans, neurologic examination, and autopsy. Twenty-four of the 75 patients had no CNS metastases. Ten of the 51 patients with CNS metastases had leptomeningeal carcinomatosis (MC). CSF-ADH was significantly increased in patients with MC (P less than .05), but not in patients having exclusively parenchymatous CNS metastases. Taking 2 pg/mL (95th percentile of control patients) as the upper limit of normal, 15 SCBC patients had elevated CSF-ADH, including 12 patients with CNS metastases and six patients with MC. The CSF-ADH to plasma ADH ratio was significantly increased in patients with CNS metastases (P less than .05). Patients without CNS metastases had a ratio less than or equal to 0.8 whereas the ratio was greater than 0.8, in 21 of the 51 patients with CNS metastases. The positive and negative predictive values with 95% confidence limits were 84% to 100% and 31% to 59%, respectively. Patients with inappropriate secretion of ADH (SIADH) constituted a significantly greater proportion of patients with elevated CSF-ADH than of patients with normal CSF-ADH levels (P less than .05). In addition, patients with SIADH constituted a significantly greater proportion of patients with MC than of patients with parenchymatous metastases (P less than .05). The diagnostic application of these findings is limited because of the large number of false-negative results, but it may prove to be of value in conjunction with the measurement of other tumor markers.

Hepatitis B virus DNA (HBV-DNA) in anti-HBe positive sera

HBV-DNA measured by the spot hybridization technique, was found in the sera of 28 of 106 (26.4%) anti-HBe positive carriers of HBsAg. Dane particle-associated HBeAg, HBcAg and HBV-specific DNA-polymerase activity were found in the sera of nine (8.5%), five (4.7%) and two (1.9%) of these patients, respectively. All carriers with serum HBV-DNA had chronic liver disease and 18 had intrahepatic delta-Ag and serum anti-delta at titers higher than 1/5000. Intrahepatic HBcAg was detected in the nuclei of 90% of delta negative individuals; 50% of them also had cytoplasmic fluorescence. Only two of the 18 patients with intrahepatic delta-Ag (11%) had HBcAg in the liver. Viral nucleic acid was not found in the sera of 15 other patients with chronic hepatitis, seven of whom had intrahepatic delta-Ag. Serum HBV-DNA was also negative in the remaining 63 symptomless carriers of HBsAg lacking markers of delta infection. Interestingly, although DNA-polymerase negative, some sera gave autoradiographic spots of high optical density. HBV-DNA was detected in them at concentrations typical of sera which are usually both DNA-polymerase and HBeAg positive. Detection of HBV-DNA in serum represents the most direct and sensitive in vitro assay for assessing HBV infectivity and characterizes HBsAg carriers with HBV-related liver damage and ongoing HBV replication independently from the state of HBeAg/anti-HBe system. In the Mediterranean area, the majority of anti-HBe positive carriers with serum HBV-DNA have chronic liver disease and delta infection.

Cerebrospinal fluid vasopressin and increased intracranial pressure

Cerebrospinal fluid and plasma vasopressin were measured in patients with cerebral disorders associated with varying levels of elevated intracranial pressure. The mean cerebrospinal fluid vasopressin concentration was significantly increased in patients with pseudotumor cerebri (2.0 +/- 0.2 [SEM] pg/ml), intracranial tumor (2.3 +/- 0.4 pg/ml), and intracranial hemorrhage (1.9 +/- 0.3 pg/ml) compared with control patients (1.2 +/- 0.1 pg/ml). A significant relationship was found between intracranial pressure and the cerebrospinal fluid vasopressin concentration within all groups of patients and in the whole sample as well (r = 0.79; p less than 0.001). In the groups of patients with intracranial tumor, hydrocephalus, and intracranial hemorrhage, some individuals showed plasma vasopressin concentrations inappropriate to the corresponding plasma osmolality, but no relationship was found between intracranial pressure and plasma vasopressin concentration. It is suggested that increased intracranial pressure is a stimulus to centrally released vasopressin. The clinical importance of increased cerebrospinal fluid vasopressin concentrations is still not known.

Effects of long-term carbamazepine treatment on water metabolism and plasma vasopressin concentration

Plasma osmolality, sodium and vasopressin were measured in 7 patients before and during long-term treatment with carbamazepine, under resting conditions, and following an oral water load of 20 ml/kg body weight. During carbamazepine treatment, the ability to excrete the oral water load was decreased, the urine/plasma osmolality ratio was higher, and the free water clearance was lower. In two patients, the ability to excrete the oral water load was severely impaired, and the free water clearance remained negative following water loading. Plasma osmolality and sodium concentration were significantly lower during carbamazepine administration, but despite this the plasma vasopressin concentration remained unchanged or was even slightly increased. Four patients showed inappropriately high vasopressin concentrations in relation to the corresponding plasma osmolality when taking carbamazepine. The findings suggest a decrease in plasma osmolality during carbamazepine treatment, which might account for the inappropriate secretion of vasopressin. The latter might cause clinical symptoms of water intoxication, as has previously been reported in a few patients on carbamazepine therapy.

CSF and plasma vasopressin concentrations in dementia

In 16 patients with primary degenerative dementia mean CSF vasopressin concentration was lower (0.9 +/- 0.1 pg/ml (mean +/- SEM)) than in 28 control patients (1.3 +/- 0.1 (mean +/- SEM)) (p less than 0.01). In 18 patients with normal pressure hydrocephalus and potentially reversible dementia mean CSF vasopressin concentration (1.2 pg/ml +/- 0.1 (mean +/- SEM)) was not different from that found in controls. Several of the demented patients had inappropriate plasma vasopressin concentrations suggesting a defect in osmoregulation. These findings encourage further clinical trials of vasopressin in patients with primary degenerative dementia, but it is emphasised that the low CSF vasopressin concentration in these patients might be only a nonspecific phenomenon due to the diffuse loss of cells within the central nervous system.

'Core' and 'extended' social networks in relation to health and illness

This paper considers several models of the nature of the association that has been found between characteristics of social networks and health. Such an association does not appear to be adequately accounted for by a deleterious effect of illness on social contact, nor by the role of social networks in mediating health-related practices or in buffering the effects of stress. Thus the proposition is tentatively warranted that the social network is more directly and causally involved in health outcomes--perhaps through the impact of social feedback as mediated by the network. It is argued that the social processes that affect the association between networks and health involve a larger social unit than the small core networks that have generally been the focus of study. Assuming that the individual's susceptibility to illness is affected by the adequacy of the core network, we must deal with the fact that the vulnerability of the core network to loss without adequate replacement is, in turn, affected by the structure of the larger, extended network in which the core network is embedded. By shifting attention to these extended networks, it should also become possible to integrate findings from network studies with more traditional epidemiological findings relating such macro-variables as social class to illness.

Unrelatedness of factor VIII-derived non-A/non-B hepatitis and hepatitis B virus

A DNA hybridization assay was used to detect hepatitis B virus (HBV)-specific DNA sequences in extracted sera obtained from chimpanzees infected with HBV, hepatitis A virus (HAV), and a factor VIII-derived non-A/non-B (NANB) agent. The results did not reveal any HBV-DNA homology with sera obtained from animals infected with HAV or factor VIII-derived NANB. Sera obtained from two HBV-infected chimpanzees demonstrated that HBV-specific DNA could be detected during the acute phase of the disease. In addition, an HBV-specific DNA-dependent DNA polymerase assay did not demonstrate any statistically significant activity in 12 of 12 NANB acute-phase specimens or in 6 of 6 NANB chronic-phase specimens. These results suggest that the factor VIII-derived NANB agent is unrelated to HBV.

Episodic secretion of vasopressin in man

The plasma arginine vasopressin concentration (pAVP) was measured in blood samples obtained from an internal jugular vein of 8 patients who underwent surgery for a carotid artery stenosis. Ten blood samples were taken with 1 min interval during the operation. Arterial pAVP was measured in 10 simultaneous samples from a radial artery and the brain venoarterial difference of pAVP was calculated. The venoarterial difference was 0-3 pg/ml in 7 of the patients, while it increased to 35 pg/ml upon baroreceptor stimulation in one patient. A pulsatile pattern was found in the veno-arterial difference of pAVP both at low and higher peripheral pAVP levels. This appeared to reflect a discontinuous release of AVP from the neurohypophysis. The described method results in a more accurate picture of ongoing secretory activity than can be obtained by measurements of peripheral pAVP alone. The general usefulness of the method, however, is restricted by the need of a multitude of samples and the difficult approach to the internal jugular vein.

Cancer in cystic lesions of the thyroid

We reviewed the records of 341 patients who underwent thyroidectomy for the suspicion of cancer between 1975 and 1980. Cancer of the thyroid was found in 14% of them. Although cysts of the thyroid (pathologic finding of a fluid-filled cavity greater than 1 cm in diameter) were encountered in 35% of the patients, cysts were similarly distributed among patients with benign conditions (27%) or with cancer (33%). Most of the thyroid cysts in patients with carcinoma measured 2 to 4 cm in diameter. The cancer was found within the cystic cavity. The cysts in patients with cancer appeared to originate from necrosis of the tumor. B-mode ultrasonography was not reliable in differentiating cystic and solid lesions. The demonstration of the cystic nature of a thyroid nodule does not rule out the diagnosis of cancer of the gland.

Vasopressin in the cerebrospinal fluid of patients with normal pressure hydrocephalus and benign intracranial hypertension

We have studied plasma and cerebrospinal fluid vasopressin (CSF-AVP) and osmolality in 28 patients with cervical or lumbar pain syndromes (control patients), 11 patients with normal pressure hydrocephalus (NPH) and in 5 patients with benign intracranial hypertension (BIH). Vasopressin concentration in lumbar CSF to a high extent reflected the actual ventricular CSF-AVP concentration. In all groups CSF-AVP was lower than plasma AVP. Mean CSF-AVP in the control group was 1.3 pg/ml +/- 0.1 (SEM). In the NPH patients, who all suffered from severe dementia, CSF-AVP level was not different from that found in the control group (1.4 pg/ml +/- 0.2). In contrast to the findings in the two other groups CSF osmolality in BIH patients was higher than plasma osmolality (P less than 0.0). CSF-AVP in the BIH patients, characterized by an elevated intracranial pressure (ICP), was higher than in the control group (2.7 pg/ml +/- 0.4, P less than 0.001).

Parenthood and social networks. A preliminary view

Data from several samples in the United States and England are drawn upon to examine how and to what extent the social networks of parents differ from those of men and women without children. The social contact patterns found to be associated with parenthood involve (1) a shift in the composition of the networks, and especially an increased emphasis on kin connections; (2) a shift in the frequency with which people are seen; and (3) an absolute reduction in network size for non-working mothers in the lowest social class. The paper briefly considers the health-related implications of these network differences, with special reference to several recent studies that have found exceptionally high rates of depression among women with young children.

Social supports, social networks, and schizophrenia

This article considers the meaning of "social support" and its relationship to social networks, and discusses a structural approach to analysis of social connections in the study of schizophrenia. The concept of social supports is seen as methodologically more problematic and less strategic than the more structurally oriented concepts of social networks and social connections. It is argued that in terms of research strategy, if social connections are studied structurally as they change and develop over time, the impact of the specifically social processes can be better separated from that of the personal characteristics of the focal individual than seems possible with other approaches. Analysis of the properties of the networks around the focal individual, independently of that individual's own social behavior, can help to disentangle the interwoven complex of causes, characteristics, and consequences of schizophrenia.

The inability of angiotensin II infusions to raise plasma vasopressin levels in haemodialysis patients

Since it has previously been claimed that angiotensin II (AII) stimulates vasopressin (AVP) secretion, the effect of AII-infusions was studied in 1) 6 normals, 2) 5 non-nephrectomized haemodialysis (HD) patients, and 3) 6 nephrectomized HD patients. In dialysis patients the infusion rate was increased step-wise from 2-12 ng AII/kg bw x min-1 and was terminated if diastolic blood pressure (BP) increased more than 20 mmHg. Normals were infused at a constant rate of 4 ng AII/kg bw x min-1. In all the groups significant increments in BP and plasma aldosterone occurred while plasma renin activity decreased. The plasma vasopressin level was unchanged in normals, while in the two groups of dialysis patients a minor decrease was found. The present study has therefore not been able to confirm a stimulating effect of a physiological dose of AII on AVP secretion, and the results in anephric patients indicate that a normal plasma AII concentration is of no importance for the plasma AVP level.

Calcium-stimulated vasopressin secretion in uremic patients: an effect mediated via parathyroid hormone?

The effect of whole blood ionized calcium levels on vasopressin (AVP) secretion has been studied in 12 uremic hemodialysis patients (6 nephrectomized and 6 nonnephrectomized), 6 healthy subjects, and a sprue patient, first while she was hypocalcemic and again after her blood calcium had normalized. Changes in whole blood ionized calcium were induced by calcium infusion (3.15 mg Ca/kg BW h-1). In uremic patients, an increase in plasma AVP took place during infusion, and the changes in AVP were correlated to the changes in whole blood ionized calcium. In normals, no changes in AVP were found. In the sprue patient, an increase in plasma AVP correlated to whole blood ionized calcium was found in the hypocalcemic state, but this could not be demonstrated after treatment. Parathyroid hormone has been shown to facilitate calcium entry into cells, and it is proposed that the pathophysiological effect of calcium on AVP secretion in uremic patients is caused by the elevated parathyroid hormone level found in these patients.

ACTH, ADH, and calcitonin concentrations as markers of response and relapse in small-cell carcinoma of the lung

The ectopically produced polypeptide hormones ACTH, ADH, and calcitonin were investigated as tumor markers in patients with small-cell carcinoma of the lung (SCC). Plasma ADH concentrations were evaluated separately as well as in relation to concomitantly obtained plasma osmolality levels. No significant nor consistent changes of marker concentrations caused by lysis of tumor cells were found immediately after administration of cytotoxic drugs. After tumor regression, plasma ACTH and serum calcitonin concentrations and inappropriate ADH secretion (plasma ADH levels inappropriately high compared with plasma osmolality) became normal in most cases; however, progressive disease was not followed consistently by changes in plasma ACTH concentrations and occurrence of inappropriate ADH secretion. Contrary to this, among 12 patients with disease progression, serum calcitonin levels increased in ten patients and plasma ADH levels increased in 11 patients. In most cases, however, these changes were only moderate, and serum calcitonin concentrations were found to be increased after tumor regression in patients who had normal pretreatment levels. It is concluded that decisions on treatment of patients with SCC cannot exclusively be based on changes in the concentrations of the polypeptide hormones that might be of ectopic origin.

Relationship between plasma osmolality and plasma vasopressin in human subjects

The relationship between plasma osmolality (pOsm) and plasma vasopressin (pAVP) was studied in 13 human subjects during dehydration. The fit of linear, log-linear, parabolic, and exponential models was tested. For all of the data, the nonlinear models had the best fit. However, when individual differences in either gain or threshold were allowed for, the linear models were better than log-linear models. Finally, analyses were made with individual data points. Linear models had the best fit in half of the subjects, whereas for the others the parabolic model gave the best fit. For those subjects investigated in the low range of the osmoregulatory curve, a linear relationship was found, whereas, for those having the most pronounced increase in pOsm, the most significant improvement was found with the parabolic model. This finding indicates that the relationship is not stable during dehydration in the whole range and that hypovolemia probably can influence the secretion rate and/or metabolic clearance rate and thereby the relationship.

Diagnostic and therapeutic implications of ectopic hormone production in small cell carcinoma of the lung

In 75 unselected and untreated patients with small cell carcinoma of the lung, plasma ACTH, serum calcitonin, and antidiuretic hormone (ADH) in plasma and urine were related to corresponding clinical symptoms and biochemical findings at the time of diagnosis. The significance of elevated concentrations of these substances in relation to treatment was also investigated. Plasma ACTH concentrations were increased in 22 patients (29%), and 25 patients (33%) were considered to have inappropriate ADH secretion. Only one patient had definite hypokalaemic alkalosis, and one patient pronounced hyponatraemia, with associated clinical syndromes of ectopic ACTH and ADH secretion. Serum calcitonin concentrations were increased in 48 patients (65%). No related clinical symptoms were disclosed, and all these patients had normal serum calcium concentrations. Thirty-three of 66 patients (50%) had raised levels of free cortisol in a 24-hour urine and these levels were significantly related to plasma ACTH concentrations. The median survival was slightly shorter in patients with increased values of the three substances, but this was not related to increased plasma ACTH concentrations and was not statistically significant. Survival rates and results of treatment were independent of the pretreatment levels of the three substances.

Traumatic hyphema. Failure of steroids to alter its course: a double-blind prospective study

Forty-three patients with traumatic hypema were studied prospectively in a controlled, double-blind study. Twenty-three patients received prednisone and 20 received a lactose placebo. Secondary hemorrhages occurred in 16% of all patients. There was no significant difference in the incidence of secondary hemorrhage between the two groups (P = .85). There is no evidence that prednisone (40 mg/day) decreases the incidence of secondary hemorrhage. There was no significant difference in final visual acuities between the two groups. Patients with initially larger hyphemas do not appear to have worse final visual acuities. Hyphemas without secondary hemorrhage had a uniformly good prognosis. Although final visual acuities were worse in eyes with secondary hemorrhage, associated ocular injuries rather than blood-related complications accounted for the decreased visual acuity.

Scintigraphic skeletal changes in non-dialyzed patients with advanced renal failure

Technetium-99m-polyphosphate (Tc-PP) bone scintigraphy was performed in 51 patients with advanced renal failure in order to evaluate the applicability of this method in detection of metabolic bone changes in these patients. The creatinine clearance varied from 2 to 40 ml/min and none of the patients had previously been on dialysis treatment. The scintigrams were graded according to the focal and the generalized abnormal uptake of the tracer in the skeleton. 34 patients showed generalized scintigraphic changes and among these the changes in 18 patients were classified as severe. An inverse correlation was found between the kidney function and the generalized scintigraphic classification. Focal bone changes were found in 11 patients. In order to evaluate the influence of the lack of kidney function on the scintigraphic results, 3 patients with acute oliguric renal failure were examined. All had normal scintigrams. It is concluded that Tc-PP bone scintigraphy is a sensitive method in revealing renal osteodystrophy in non-dialyzed patients with advanced renal failure in agreement with previous reports on patients on chronic hemodialysis and after kidney transplantation.

Pseudomonas aeruginosa bacteremia: susceptibility of 100 blood culture isolates to seven antimicrobial agents and its clinical significance

The susceptibility of 100 blood culture isolates of Pseudomonas aeruginosa observed during 4 1/2 years was tested for tobramycin, netilimicin, gentamicin, amikacin, pirbenicillin, ticarcillin and carbenicillin, singly and in combination. For aminoglycosides, the agar MICs were twofold to threefold greater than tube dilution MICs but for the penicillins they were similar. For aminoglycosides and ticarcillin, the MBCs were twofold greater than the tube dilution MICs. The MBCs were not achieved at concentrations as high as 512 micrograms/ml for 40% of the isolates for pirbenicillin and for 10% for carbenicillin. Tobramycin and pirbenicillin had the lowest MICs for the aminoglycosides and penicillins, respectively. Synergism was tested and observed between tobramycin + ticarcillin and amikacin + ticarcillin. No overall increase in resistance to gentamicin or carbenicillin was seen from 1974 to 1977. However, patients given repeated courses of gentamicin had more resistant strains. Following the administration of 1.5 mg/kg/dose of gentamicin, peak serum concentrations failed to achieve the MIC for the microorganism in 22% of the patients. The MIC was achieved in all patients receiving the same dose of tobramycin. The overall fatality rate was 67% with one third of the patients dying within 36 hr. There was no relationship of patient fatality rate and MIC for the microorganism. Although in the rapidly fatal group of all patients receiving inappropriate therapy died, the fatality rates of appropriately or inappropriately treated patients in the ultimately fatal and nonfatal groups were similar. Underlying host disease was the major determining factor in patient survival.

Pseudomonas aeruginosa bacteremia: relationship of bacterial enzyme production and pyocine types with clinical prognosis in 100 patients

Strains of Pseudomonas aeruginosa were studied from 100 patients with bacteremia. In vitro quantitation of extracellular enzymes (lecithinase, protease, and elastase) and pyocine typing of these isolates were performed. No significant difference was found in the quantity of the enzymes produced or in the pyocine types by isolates obtained from patients dying from bacteremia or surviving this serious infection. Quantitation of the extracellular enzymes and pyocine types of blood isolates were contrasted with similar data obtained from sputum, urine, and skin isolates. One third of all strains produced minimal or no extracellular enzymes regardless of their source. However, the highest enzyme-producing strains were observed in the blood isolates. Although a greater variability of pyocine types was found in blood culture isolates, there was no significant difference between the pyocine types found in blood, urine, sputum, or skin isolates. The lack of correlation between the in vitro quantity of lecithinase, protease, and elastase produced by P. aeruginosa strains isolated from bacteremic patients and the prognosis of these patients supports the possible local rather than systemic significance of these extracellular enzymes in the pathogenesis of P. aeruginosa bacteremia.

Radioimmunoassay of 8-arginine-vasopressin (antidiuretic hormone) in human plasma

A radioimmunoassay for 8-arginine-vasopressin (AVP) measurement in human plasma has been developed and evaluated, using a commercial preparation of an antibody of AVP. Detection limit of the assay was 0.4 pg. A simple acetone extraction procedure gave a recovery of 65% of added [125I]AVP. The overall sensitivity in the assay was 1.0 pg/ml when 2 ml plasma samples were extracted. The antigenic sites of the employed antibody seemed to be a combination of amino acid residues in the tripeptide tail and the pentapeptide ring. This can explain that the antibody was almost completely insensitive to chemically or enzymatically degraded AVP. The inter-assay coefficient of variation for the control plasma pools averaged 17%. A good correlation to plasma osmolalities above 290 has been found. AVP level in recumbent subjects (n = 8) with plasma osmolalities in the normal range was 2.8 +/- 1.0 pg/ml (mean +/- SD) and in ambulatory subjects (n = 10) on ad lib. water intake 4.5 +/- 1.9 pg/ml (mean /+- SD).

Calcium-dependent aldosterone secretion in anephric and nonnephrectomized patients on regular hemodialysis

The present study was undertaken to investigate the effect of a continuous calcium infusion on the plasma levels of aldosterone, renin activity, and cortisol in six anephric and four nonnephrectomized patients on regular hemodialysis. In both groups, a significant increase in whole blood ionized calcium (b-Ca2+) was demonstrated. A significant increase in plasma aldosterone (PAC) was noted in the nonnephrectomized patients, in whom the rise in PAC correlated with the increase in b-Ca2+. However, in the anephric patients only a smaller and insignificant increase in PAC was found. No significant changes were demonstrated in plasma cortisol or renin activity, nor in potassium or sodium concentrations in either group. It is concluded that ionized calcium influences the plasma levels of aldosterone in uremic patients on regular hemodialysis.

Social networks and schizophrenia

This article suggests that social network concepts and methods can provide a unifying framework for social research on schizophrenia. A selective review of the literature indicates that a social network perspective is not only consistent with a range of other research approaches and findings, but may help resolve some basic and persistent methodological and conceptual problems. A theoretical model is briefly described which attributes a critical role in the onset and recurrence of schizophrenia to social network processes. Some examples are given of the potential contribution of social network variables to research and therapy in schizophrenia.

Circadian rhythm of plasma aldosterone and plasma renin activity in steroid and non-steroid treated kidney transplanted patients

The circadian rhythm of plasma aldosterone (PAC) and cortisol concentration (PCC), and renin activity (PRA) was measured in five steroid and five non-steroid treated kidney transplanted patients--all with denervated kidney grafts--and compared with four normal controls and two steroid-treated patients with non-renal disease and thus normal renal innervation. The non-steroid treated patients had a normal circadian thythm of PAC and PCC, but without variation of PRA, suggesting that denervation of the kidneys has no influence on the circadian rhythm of PAC. In both steroid treated groups the PAC showed an inverse diurnal variation--now correlating to the diurnal variation in PRA. The inverse circadian rhythm of PAC in patients with suppressed ACTH secretion remains unexplained, but is in accordance with the nocturnal peak of sodium and water excretion in steroid treated patients.

Urinary pseudouridine and beta-aminoisobutyric acid in patients with low grade urothelial tumours. Relations between excretion and tumour recurrence

The simultaneous 24 hours excretion of pseudouridine and beta-aminoisobutyric acid in the urine from patients treated for low grade urothelial tumours has been determined and related to tumour recurrence inside of 6 months after the determinations. The results of 53 assays in 39 patients without clinical signs of recurrence at the time of the detrmination showed a high excretion of pseudouridine in 53% and of beta-aminoisobutyric acid in 28.5% of the assays. Recurrences appeared more often after a high urinary pseudouridine (53.5%) than after a low, but the difference was not statistically significant (p more than 0.05) and more often after a low urinary beta-aminoisobutyric acid (52.5%) than after a high (p less than 0.01). The highest incidence of recurrence was in patients with a simultaneously high urinary pseudouridine and a low urinary beta-aminoisobutyric acid. Seventy per cent of these excretion patterns were from patients, who developed a recurrence before 6 months (p less than 0.002).

A study on the clinical significance of urinary beta-aminoisobutyric acid in patients with urothelial tumours

Urinary beta-aminoisobutyric acid (beta-AIB) has been measured in 141 patients with urothelial tumours and 60 controls. Ninetyone of the patients have been followed-up for an average period of about 2 years, which included many determinations of the beta-AIB excretion. Thirtysix patients died during the control periods. Urinary beta-AIB was found to be significantly correlated to the grade of tumour cell dysplasia, but not to the clinical tumour stage. The treatment had no major influence on the excretion. Characteristic changes in the excretion preceding high-grade tumour recurrences are demonstrated. Autopsy findings with tumour tissue in the urinary tract and distant metastases were significantly correlated to a low urinary beta-AIB in the terminal phase of the disease. The results are discussed in relation to the degradation of thymine, the dual origin of beta-AIB and the tumour-host metabolism. It is concluded, that urinary beta-AIB can contribute to the graduation of malignancy, but is not valuable as a general screening procedure for urothelial cancer.

Relationship between effective intensity of auditory stimulation and directional eye turns in the human newborn

To examine Schneirla's biphasic hypothesis that effectively weak stimulation results in approach-type responses and effectively strong stimulation results in withdrawal-type responses, 90 dB white noise stimuli were presented to twenty-five, 2-day-old female infants. Based on prior investigation this stimulus was expected to be effectively strong when presented at the right ear and effectively weak when presented at the left ear. Results obtained from electro-oculargraphic recording of the infants' eye movements supported this hypothesis in that significant towards-turning occurred when the stimulus was presented at the left ear and significant away-turning occurred when the stimulus was presented at the right ear.

Gap junction formation between reaggregated Novikoff hepatoma cells

We have combined freeze-fracture and electrophysiological methods in a study of gap junction formation between reaggregated Novikoff hepatoma cells. Cell clumps are dissociated with EDTA, and the resulting single cells are allowed to reaggregate (5-180 min) in loose pellets in the presence of calcium at 37 degrees . The earliest electron microscopic evidence for the genesis of new junctions is the appearance of flattened regions of the plasma membrane with a relative paucity of small intramembranous particles. These regions contain instead loosely organized groupings of 9- to 11-nm intramembranous particles, which are seen on the A face of the fractured plasma membrane, while corresponding pits occur on the membrane B face. We have termed the specialized membrane regions "formation plaques." They are seen as early as 5 min after reaggregation and are quite numerous by 30 min. Larger plaques are observed at later times. Plaques seen at 30 min are consistently matched with other plaques on apposed cells, although the extracellular space separating these structures still exceeds 10 nm. By 60 min, some matched plaques display a reduced extracellular space, resembling that of normal gap junctions. Between 30 and 60 min, aggregates of closely packed particles on A faces and hexagonally arranged pits on B faces frequently appear in the formation plaques. The aggregates, which are indistinguishable from small gap junctions, appear to enlarge over the subsequent 2-hr period as the number of unaggregated 9- to 11-nm particles declines. Microelectrode studies demonstrate progressive increases in the percent of interfaces containing lowresistance junctions and in the degree of elctrical coupling in preparations incubated up to 2 hr. Coupling is first detected at about the same time as particle aggregates (or formation plaques with reduced extracellular spaces), and increases as aggregate sizes increase.

A new species of oribateid mite from Queensland

A new species of oribateid mite, Zygoribatula longiporosa, is described from pastures in Queensland.