The dynamics of testosterone and dihydrotestosterone metabolism in the adult male rhesus monkey.

MCRs of testosterone (T) and 5 alpha-dihydrotestosterone (DHT) were determined in the morning and evening in four chronically chaired adult rhesus monkeys (Macaca mulatta) by means of steady state infusion of [4-14C]testosterone and [1,2-3H]dihydrotestosterone. Morning and evening MCRs were comparable for both T and DHT, averaging 169 and 212 ml/min for T and 93 and 108 ml/min for DHT, respectively, indicating that temporal differences in blood steroid concentrations are the result of changes in glandular secretion and/or synthesis and not differences in MCRs. Blood transfer factors for the conversion of T to DHT were also similar at these two times (0.024 and 0.022). MCRs were determined in one monkey by the single injection of [14C]T and [3H]DHT. From the rates at which the hormones disappeared from the circulation, MCRT and MCRDHT were calculated to be 172 ml/min for T and 92.2 ml/min for DHT. The inner volumes of hormone distribution were 4.04 liters for T and 3.67 liters for DHT.


Further studies on the effects of lesions in the rostral hypothalamus on gonadotropin secretion in the female rhesus monkey (Macaca mulatta).

Bilateral radiofrequency lesions were stereotaxically placed in the rostral hypothalamus of four adult female rhesus monkeys. These lesions resulted in extensive destruction of the ventromedial preoptic-anterior hypothalamic area (POA-AHA) and included the suprachiasmatic nucleus as well as, with the exception of one animal, the organum vasculosum of the lamina terminalis. In three of these four animals, gonadotropin surges similar to those observed before surgery were elicited in response to either a spontaneous increment in serum estrogen concentration or an estradiol benzoate injection. This stimulatory action of estradiol on LH and FSH release was not demonstratable in the remaining lesioned animal, but estradiol benzoate injections also failed to elicit a gonadotropin discharge in one of a series of five normal control animals. These findings fail to support the view that destruction of the ventromedial POA-AHA in this species compromises the ability of the hypothalamicohypophysial apparatus to respond to the positive feedback action of estradiol. The diurnal variation in serum cortisol concentration was not interrupted by placement of the lesions in the ventromedial POA-AHA.


Pharmacological interactions of mesuximide with phenobarbital and phenytoin in hospitalized epileptic patients.

In order to study the pharmacological interactions of the anticonvulsant drugs mesuximide (MSM), phenobarbital (PB), and phenytoin (PHT), serum concentrations of N-desmethyl-mesuximide (N-DESM-MSM, the main metabolite of MSM), PB, and PHT were determined in 94 hospitalized patients suffering from petit mal epilepsy. When MSM was administered to patients on stable PB or primidone therapy, the mean concentrations of PB increased by statistically significant amounts of 38 and 40%, respectively. Similarly, the additional administration of MSM caused the mean concentration of PHT to rise by 78%. The data also indicate that patients with PB and/or PHT comedication have higher N-DESM-MSM serum concentrations than patients without comedication. The pharmacological reasons for these interactions are discussed. These studies demonstrate that the disturbing side effects of MSM are often due to the co-medication. A carefully planned therapeutical dose procedure with regular serum level determinations is proposed to avoid or at least reduce the adverse effects of MSM.


The influence of attending on seizure activity in epileptic monkeys.

Six studies are presented on the influence of attending upon epileptic activity in the alumina-gel monkey model of focal motor and secondarily generalized tonic--clonic seizures. Seizure frequency and EEG paroxysms are reported during (a) scheduled feeding periods, (b) visual attending, and (c) three different operant tasks, including the conditioning of single neurons. An explanatory hypothesis of the cumulative data is proposed in terms of the different bursting behavior of group 1 (strongly epileptic) and group 2 (weakly epileptic) neurons of the epileptogenic focus. It is suggested that attending, or participation in operant tasks, results in a decrease in bursting of group 2 neurons and a disruption of synchrony between group 1 (pacemaker), group 2, and normal neurons. This desynchronization is said to lower the probability of an ictal event occurring either during or immediately following an operant task. Attending factors may be responsible for some of the conflicting findings in therapeutic studies of epilepsy which have not controlled for this parameter.


Carbamazepine revisited in a monkey model.

In a previous study on carbamazepine (Lockard et al., 1974), the problem of its low bioavailability in solid form and its short half-life in monkey were addressed. The present research was designed to evaluate carbamazepine under constant-rate intravenous infusion in our alumina-gel monkey model. Since carbamazepine is insoluble in an aqueous solution, polyethylene glycol 400 was used as the vehicle for administration of this drug to a group of 8 epileptic monkeys. The attenuation of seizures by carbamazepine was not statistically significant since the serum levels of carbamazepine after enzyme induction were less than 2.0 micrograms/ml. This study (a) illustrates that some problems in drug evaluation may be insoluble with our present technology even though we are cognizant of them; (b) makes explicit the fact that the efficacy of carbamazepine is a function of adequate serum levels; (c) demonstrates endogenous oscillations of carbamazepine serum concentrations; and (d) reports simultaneous serum levels of carbamazepine and its 10--11 epoxide in the monkey model.


Factors influencing the response of human blood platelets to analogues of ADP which may act as partial agonists at the ADP receptor.

1. The prior addition of non-aggregating concentrations of the divalent cation ionophore, A-23187, causes human platelets to aggregate in response to a subsequent addition of the 2',3'-dialdehyde and 2',3'-dialcohol derivatives of ADP (oADP and or ADP). Previous studies [Pearce et al. (1978) Eur. J. Biochem. 88, 543--555] have shown that these derivatives act as partial agonists at the platelet ADP receptor inducing only the transition from discoid to globular morphology ('shape change'). A secretion response is also observed on addition of a low concentration of ionophore A-23187 prior to orADP. These responses are not observed if ionophore A-23187 is added prior to the 2',3'-dialdehyde and 2',3'-dialcohol derivatives of ATP (oATP and or ATP) and are markedly inhibited by prior addition of the ADP antagonist, adenosine 5'-[beta, gamma-methylene]triphosphate. 2. The aggregation response to oADP in the presence of ionophore A-23187 is reduced but not eliminated by addition of 3 mM EGTA when studies are performed in heparinised platelet-rich plasma. Additions of 3 mM EGTA in citrated platelet-rich plasma, or of 4 mM EDTA in either system completely inhibits this response. Inhibitors which are reported to elevate the intracellular concentration of adenosine 3':5'-monophosphate (cyclic AMP) or to prevent Ca2+ movement also inhibit the aggregation response to oADP which is observed in the presence of ionophore A-23187. 3. Prior addition of inhibitors of adenylate cyclase fails to cause an aggregation response to subsequent addition of oADP or orADP. Certain of these inhibitors enhance and prolong the shape change response to oADP or orADP but only at concentrations an order of magnitude in excess of those required to antagonise inhibition by agents such as prostaglandin E1, which act by increasing the concentration of cyclic AMP. 4. The concentration of prostaglandin E1, adenosine or papaverine required to inhibit shape change induced by oADP is one to two orders of magnitude lower than that required to inhibit shape change induced by ADP. 5. Prior addition of oADP decreases the lag phase in the response of human platelets to arachidonate while also increasing the concentration required to observe half-maximal response, and causing a decrease in the extent of the response. Prior addition of oATP also diminishes the extent of this response and increases the concentration of arachidonate required but has no effect on the lag phase. 6. The data suggest that oADP and orADP are capable only of acting as partial agonists at the ADP receptor because of a defective ability to increase cytosolic Ca2+ concentration. The defect is rectified by the presence of low concentrations of ionophore A-23187, which promotes mobilisation of Ca2+ from an intracellular store. The results do not appear consistent with the thesis that a decrease in platelet cyclic AMP is an initiating event in aggregation induced by ADP, but do support a model which implicates cyclic AMP in depletion of cytosolic Ca2+.


Synthesis of carbonic anhydrase in rabbit and chicken reticulocyte lysates.

The synthesis of carbonic anhydrase, the second most abundant soluble protein of red blood cells, is shown to occur in rabbit and chicken reticulocyte lysates. This translation product was identified by chloroform/ethanol extraction, polyacrylamide gel electrophoresis in sodium dodecylsulphate and peptide mapping. In rabbit retic-locyte lysates, predominantly one of the two red cell isozymes, carbonic anhydrase I, is synthesised. The proportion of carbonic anhydrase synthesis (0.2-0.8% of total protein synthesis) in vitro is comparable to that (0.2-1.0%) in vivo for both rabbit and chicken reticulocytes.


Colivirus-T3-coded S-adenosylmethionine hydrolase.

Bacteriophage T3 induces an enzyme activity which hydrolyzes S-adenosylmethionine. This S-adenosylmethionine hydrolase is interesting, not only because of its unique activity, but also because the protein has to overcome host restriction [F. W. Studier and N. R. Movva (1976) J. Virol. 19, 136-145]. S-Adenosylmethionine hydrolase was purified to homogeneity using affinity chromatography on S-adenosylhomocysteine-Sepharose. The enzyme occurs in two forms, A and B. Form A consists of the viral peptide chain only; its native and subunit molecular weight is 17,000. Form B contains, in addition, a host subunit with a molecular weight of 49,000. The host subunit does not modify S-adenosylmethionine cleavage in vitro and no apparent relationship to the host-restriction system could be detected.


Inhibition of the aliphatic amidase from Pseudomonas aeruginosa by urea and related compounds.

The time-dependent inhibition of amidase from Pseudomonas aeruginosa strain AI 3 by urea, hydroxyurea and cyanate displayed saturation kinetics fitting a model for the reaction sequence in which formation of a complex in a reversible step was followed by an irreversible step. Altered amidases from mutant strains AIU 1N and OUCH 4, selected for their resistance to inhibition of growth by urea and hydroxyurea respectively, had altered kinetic constants for inhibition indicating reduced binding capacity for the inhibitors. The substrate acetamide protected AI 3 amidase against inhibition by urea,.and altered Ki values for inhibition of the mutant amidases were paralleled by alterations in Km values for acetamide indicating that urea acted at the active site. Inhibition of AI 3 amidase involved the binding of one molecule of urea per molecule of enzyme. Urea inhibited amidase slowly regained activity at pH 7.2 through release of urea.


A novel SH-type carboxypeptidase in the inner membrane of rat-liver mitochondria.

A carboxypeptidase from rat liver mitochondria was partially purified by discontinuous sucrose gradient centrifugation, washes with NaCl/KBr/Tris buffer, and solubilization with 2 M NaCl in the presence of soybean trypsin inhibitor bound to CM-cellulose. By means of dodecylsulfate/polyacrylamide gel electrophoresis a molecular weight of 34,500 was determined; a value of 38,000 was estimated by Sephadex G-100 gel filtration. The carboxypeptidase was completely inhibited by 3 mM Hg2+. In the presence of 3 mM Cu2+ 50% of the catalytic activity was inhibited. Among several peptides tested Cbz-Ala-Phe, Cbz-Leu-Phe, Cbz-Phe-Leu, and Cbz-Phe-Phe, were good substrates. The enzyme activity exhibited a pH optimum of around 9 with Cbz-Ala-Phe as a substrate. After submitochondrial fractionation it was found that the carboxypeptidase is located in the inner mitochondrial membrane.


The role of components of the endoplasmic reticulum in the biosynthesis of cytochrome P-450.

1. Antibodies have been prepared to rat hepatic cytochrome P-450 and their specificity demonstrated. These antibodies have been used to investigate the biosynthesis of cytochrome P-450 in vitro and in situ in various components of the endoplasmic reticulum. 2. A preparation of heavy rough endoplasmic reticulum translocates proteins newly biosynthesized in vitro vectorially into the luminal space and these are released by low concentrations of deoxycholate. A significant proportion of the radioactivity found in this released fraction is incorporated into cytochrome P-450. 3. Following incorporation of [14C]leucine by perfused rat liver, radioactively labelled cytochrome P-450 can be found in the intrascisternal content of heavy rough, light rough and smooth endopalsmic reticulum and also in a solublized Golgi preparation. 4. We suggest that at least part of the newly biosynthesized cytochrome P-450 is translocated into the intracisternal space of the rough endoplasmic and then passes through the other components of the endoplasmic reticulum before insertion at its ultimate membrane locus.


Antiepileptic therapy with phenytoin: which is the optimum serum level?

114 patients suffering from generalized grand mal seizures were treated with phenytoin only. Serum-phenytoin was monitored, and its relation to the frequency of attacks was established in each case, observing steady state periods of at least 3 months' duration. In a group of 44 patients the reduction in pretreatment frequency of attacks was used to evaluate the drug effect. The probability of attacks followed an exponential function of serum-phenytoin. Curves of equal probability for further attacks were plotted: they may assist in determining the initial regimen. However, the high variability in responsiveness during a serum-phenytoin below 10 mg/l suggested that the effective level has to be determined separately and repeatedly for every single patient.


Tendency to periodic recurrence of EEG changes in Lafora's disease. Case report.

A young male patient affected with Lafora's disease and concomitant mental deterioration, myoclonic jerks and epileptic seizures is reported. A cerebral biopsy showed round PAS-positive myoclonus bodies in nerve cells and neuropile. A tendency to periodic recurrence of paroxysmal activity in the EEG tracings, an unusual finding in Lafora's disease, is briefly discussed.


Chronic administration of chenodeoxycholic acid increases cholesterol saturation in bile in the dog.

Six dogs were given chenodeoxycholic acid, 200 mg/day for 15 days; gallbladder and hepatic bile samples were taken and biliary bile acids, phospholipids and cholesterol were compared to those of fourteen control dogs. It was found that: (1) the cholesterol saturation index of gallbladder bile was higher in treated dogs (0.12 +/- 0.06; m +/- SD) than in controls (0.07 +/- 0.01; P less than 0.05); the proportion of chenodeoxycholic acid in gallbladder bile was higher in treated dogs (27.8 +/- 12.5%) than in controls (4.5 +/- 1.9%; P less than 0.01); (2) in hepatic bile, the saturation index and proportion of chenodeoxycholic acid were significantly higher in treated dogs (respectively 0.13 +/- 0.03 and 21.6 +/- 8.8%) than in control dogs (respectively 0.07 +/- 0.01; P less than 0.01 and 4.6 +/- 2.2%; P less than 0.01). In the dog, chronic administration of chenodeoxycholic acid increases cholesterol saturation in bile. It is concluded that the difference of effect of chenodeoxycholic acid in man and in the dog is not related to the duration of administration, but to a species difference.


Renal excretion of proteins and enzymes in workers exposed to cadmium.

The proteinuria rate and the relative clearances of beta 2-microglobulin, orosomucoid, albumin, transferrin and IgG were measured in forty-two workers exposed to cadmium and in seventy-seven control workers. A tubular type proteinuria with an increased excretion of beta 2-microglobulin and often also a glomerular type proteinuria with an increased excretion of orosomucoid, albumin, transferrin and IgG were observed mainly in workers exposed to cadmium for more than 25 years and whose cadmium concentration in blood exceeded 1 microgram Cd/100 ml and that in urine 10 microgram Cd/g creatinine. The glomerular dysfunction was also suggested by an increased plasma level of beta 2-microglobulin and creatinine. Both tubular and glomerular impairments occurred with the same prevalence and were not necessarily associated. The increased release of beta-galactosidase by the kidney suggested that cadmium can damage some epithelial cells.


Uraemic sympathetic neuropathy after haemodialysis and transplantation.

Autonomic function in patients with uraemia treated conservatively, by haemodialysis, and by transplantation was evaluated by the pupillary reaction to tyramine, the Valsalva manoeuvre and a postural tolerance test. The pupillary reaction to tyramine is diminished in haemodialysis patients compared with control subjects. Renal transplantation improves, but does not correct the pupillary reaction to tyramine. The frequency of the diminished response roughly correlates with the degree of renal insufficiency, with results of a Valsalva manoeuvre, and with postural tolerance tests. Our data show that uraemic autonomic dysfunction is improved by successful renal transplantation, but not by adequate haemodialysis.


Effects of chlorpromazine hydrochloride on bile salt synthesis, bile formation and biliary lipid secretion in the rhesus monkey: a model for chlorpromazine-induced cholestasis.

We studied the acute effects of intravenous infusions of chlorpromazine hydrochloride on bile salt synthesis, bile formation and biliary lipid secretion in the alert female Rhesus monkey prepared with a total biliary fistula and in a steady bile salt secretory state. In twelve studies (three animals), five doses of radiolabelled chlorpromazine hydrochloride (1-10 mg identical to 2.8-28 mumol/kg) were infused intravenously for 1 h in random order. Cholestasis was induced within minutes in all experiments. The radiolabel appeared rapidly in bile, with similar recoveries in bile and urine and a 90% total cumulative output in 4 days. Both bile flow, bile salt and other biliary lipid outputs were inhibited in a dose related and reversible manner. The apparent bile salt independent bile flow was consistently abolished, and a prompt return to basal values occurred when biliary concentration of the drug and metabolities fell below 1-2 mM. When chlorpromazine hydrochloride was infused at three doses (2.5, 5.0 and 10.0 mg identical to 7-28 mumol/kg) during constant intravenous infusion of 14C sodium taurocholate (300 mumol/h), bile flow, total bile salt output and 14C taurocholate output decreased within minutes. This was accompanied by a progressive rise in the serum 14C taurocholate concentration. After 90 min the taurocholate specific activity in bile increased significantly indicating that bile salt synthesis was inhibited. Secretion of retained bile salts and reversal of inhibition of bile salt synthesis occurred with time: the course of both events was correlated with the dose of the drug. Thus, in monkeys, chlorpromazine hydrochloride induces reversible, dose related cholestasis suppression of the bile salt dependent and independent flow, inhibition of bile salt synthesis and impairment of biliary lipid secretion. We suggest that these effects are due to both bile salt-chlorpromazine interactions and the effect of the latter on canalicular and other membranes.


Partial deficiency of hypoxanthine-phosphoribosyltransferase:evidence for a structural mutation in a patient with gout.

A mutant hypoxanthine-phosphoribosyltransferase (EC 2.4.2.8.) from a patient with gout is examined. The activity of the erythrocyte enzyme is about 5% of normal in this case. Immunoprecipitation studies using antiserum against highly purified human hypoxanthine-phosphoribosyltransferase reveal that the patient's erythrocytes contain a normal amount of cross-reacting material. The mutant enzyme has an altered net charge as shown by preparative isoelectric focusing (pI values of 5.75 and 4.55). The influence of chemical modification on enzymic activity was studied using a number of different reagents directed against sulfhydryl-, amino-, and guanidino-groups. Compared with normal hypoxanthine-phosphoribosyltransferase the mutant enzyme shows a generally lowered susceptibility to active site-directed inhibition. It is concluded that the patient's enzyme is the product of a structural mutation.


The effects of albumin bound fatty acids on the platelet inhibitory function of human endothelial cells.

This study was carried out to evaluate the effects of albumin-bound fatty acids on the anti-platelet effects of endothelial cells. Primary cultures of human endothelial cells (ECM), grown in confluent monolayers, were incubated with plasma or growth medium enriched with albumin-bound fatty acids (FA) for 2-20 h. The effects of ECM on ADP-induced platelet aggregation (PA) and collagen-induced PA and prostaglandin synthesis in platelet-rich plasma were tested. ECM released an inhibitor of platelet reactions which resembled the activity of PGI2 (prostacyclin). The inhibitory activity was increased by preincubation of ECM with arachidonic acid (AA). A moderate decrease of the activity was obtained by incubation with long-chain saturated, monoenoic and dienoic unsaturated fatty acids. A pronounced decrease of the inhibitor was obtained by incubation with di-homo-gamma-linolenic acid (DHLA). Paired combinations of AA with the other fatty acids in the incubation medium partially restored the inhibitory activity obtained by the separate FA. The stimulation of the inhibitor by AA was dose dependent and high concentrations of AA reduced this activity. The present study indicates that the quantity and quality of the plasma free fatty acids can affect the endothelial cells' ability to act as a non-thrombogenic surface.


Esterification of cholesterol in human small intestine: the importance of acyl-CoA:cholesterol acyltransferase.

Human intestinal mucosa contains acyl-CoA:cholesterol acyltransferase activity. The enzyme has been studied by using oleylcarnitine, CoA and carnitine palmitoyltransferase as an oleyl-CoA regenerating system. The enzyme was found in the particulate fraction of the cells, it had a pH optimum between 7.2 and 8.2, and was inhibited by taurocholate. The specific enzymic activity in biopsies from intestinal mucosa of normal men was found to be 3.6 +/- 1.37 nmol cholesteryl ester formed mg protein-1 h-1, an activity which can account for all cholesteryl esters in intestinal lymph. Low enzymic activity was found in biopsies from patients with small intestinal disorders. Two pancreatectomized patients had values within the normal range.


Renin, aldosterone and renal haemodynamics in cirrhosis with ascites.

The interrelationships between the renin-angiotensin-aldosterone system, renal haemodynamics and urinary sodium excretion were investigated in fifty-six non-azotaemic cirrhotics with ascites. In twelve additional patients the renal renin secretion rate was also studied. Plasma renin activity and concentration and plasma aldosterone ranged from normal to very high values. There was a significant inverse relationship between plasma aldosterone and the urinary sodium excretion. Plasma aldosterone showed a highly significant direct correlation with plasma renin activity, and plasma renin concentration was closely and directly related to the estimated renin secretion rate. Neither plasma renin activity, plasma renin concnetration nor the estimated renin secretion rate correlated with the renal plasma flow or the glomerular filtration rate. These results suggest that in non-azotaemic cirrhosis with ascites the renin-angiotensin-aldosterone system is an important factor influencing sodium excretion, increased plasma renin and aldosterone concentrations are mainly due to an increased secretion rate, and total renal perfusion is not a major factor influencing renin secretion.


A clinical and immunopathological study of 304 cases of glomerulonephritis in Tunisia.

304 cases of glomerulonephritis were biopsied in Tunisia and studied morphologically. The incidence of glomerulonephritis with marked proliferation of endocapillary cells was 60%, a figure considerably higher than in other large series. Using a Clq binding assay, statistically significant levels of immune complexes were found in cases of acute proliferative glomerulonephritis. Amongst other types of glomerulonephritis, circulating immune complexes were frequently found in systemic lupus erythematosus but only in a low percentage of primary glomerulonephritis with or without immunoglobulin deposits.


Visual suppression from nondominant eye in the lateral geniculate nucleus: a comparison of cat and monkey.

We have studied the suppression of firing in single LGN cells of cat and monkey in response to visual stimulation of the nondominant eye. In the cat LGN most of the cells of each of the main laminae show this nondominat suppression. X cells having their dominant input from the ipsilateral eye were suppressed to a significantly greater degree than any other cell type in the cat LGN. In the monkey LGN nondominant suppression was absent in all 19 X-like cells studied, whereas 6 of 21 Y-like cells showed nondominant suppression. Thus nondominant suppression is present in the magnocellular laminae of the monkey LGN, where the Y-like cells are found, but appears to be absent from the parvocellular laminae, where the X-like cells are found.


Three methods to elicit sigma-optokinetic nystagmus in Java monkeys.

Sigma-optokinetic nystagmus (sigma-OKN) can be elicited in awake Java monkeys (Macaca fascicularis) when stationary periodic visual patterns (grid of black white stripes, row of equally spaced dots) are illuminated stroboscopically. Three methods were found to be useful in inducing the sigma-OKN: postrotatory nystagmus, optokinetic afternystagmus (OKAN) following normal OKN and a gradual transition from phi-movement (phi-OKN) to sigma-OKN. The properties found for sigma-OKN in man are also present in monkeys with the one exception that monkeys have a long-lasting sigma-OKAN in darkness which is not present in man. The average angular speed Ve of sigma-OKN slow phases was related to the flash frequency fs and the spatial period Ps of the stripe pattern according to the following equation: Ve = k.Ps . fs [degrees . s-1] The constant k was 1 or close to 1.


A quantitative study of chromatic organisation and receptive fields of cells in the lateral geniculate body of the rhesus monkey.

The responses of neurones in the lateral geniculate nucleus (LGN) were investigated in anaesthetised rhesus monkeys. A new classification for cells in the parvocellular layers (PCL) is proposed, based on their spectral response curve and their response to white stimuli: (A) narrow-band, short wavelength (NS) excited cells, activity suppressed by white stimuli; (B) wide-band, short-wavelength (WS) excited cells, excited by white stimuli; (C) wide-band, long-wavelength (WL) excited cells, (D) narrow-band, long-wavelength (NL) excited cells, activity suppressed by white stimuli; (E) light suppressed (LI) cells, activity suppressed by all wavelengths, usually with some concealed excitatory input at extreme short or long wavelengths. Responses to moving bars and to spots of various diameters (area response curves) were determined for various wavelengths. It was found that the receptive fields from which wavelength-dependent excitatory or suppressive effects could be elicited are concentrically superimposed. The spectral responsiveness of the excitatory inputs to individual cell types corresponds to the absorption curves of single cones (S-, M- or L-cone for NS, WS and WL cells respectively), the spectral distribution of the suppressive mechanisms of all cells was panchromatic and approximately fitted to a sum of all cones. The excitatory input to NL-cells cannot be related to any of the known cone absorption curves, and a simple (L-M) subtraction model is questioned. Neurones in the magnocellular layers (MCL) can be divided into on- and off-centre cells as in the cat's LGN and give qualitatively similar responses over the whole spectrum. In contrast to the tonic responses of PCL cells, MCL cells respond phasically to chromatic and white flashed spots, even with the smallest stimuli. Implications of these findings for colour processing in the LGN are discussed.


The responses of magno- and parvocellular cells of the monkey's lateral geniculate body to moving stimuli.

The responses to moving stimuli of single cells in the parvo- and magnocellular layers (PCL and MCL) of the macaque lateral geniculate nucleus (LGN) have been studied. PCL cells respond with a monophasic increase or decrease in firing when a bar passes across the receptive field, according to the wavelength composition of the stimulus. MCL cells respond with a biphasic sequence of excitation and suppression or vice versa dependent on whether a cell is on-centre or off-centre and on stimulus contrast direction. With large stimuli, PCL cells respond as long as the stimulus covers the receptive field while MCL cells respond only at the contrast borders. MCL cell responses are maximal with bars just long enough to cover the field centre, while PCL cell responses show a variable relation with bar length, depending on stimulus wavelength and receptive field structure. PCL cells show broad velocity tuning while at least some MCL cells were more sharply tuned. Many cells in the macaque LGN show weak orientation or direction preference.


Rural and urban family planning services in the United States.

Family planning programs have become more efficient. It cost $66 per patient in 1976 to provide services in both rural and urban programs--the same cost reported in 1971, despite a 40 percent increase in prices since that time. Rural programs are dominated by health departments, lack health professionals, are more likely to insist teenagers have parental consent.


Gastrointestinal peptides in the brain.

Both immunoreactive intact cholecystokinin (CCK33) and its COOH-terminal octapeptide (CCK8) are detected in brain and gut extracts of monkey, dog, and pig using an antiserum with equivalent sensitivities for detecting CCK8 in the free form or when incorporated in the intact molecule. The failure to detect intact cholecystokinin in extracts from monkey or dog by using an antiserum developed by immunization with porcine CCK33 is due to marked species differences in the NH2-terminal portion of the molecule. Immunohistochemical staining reveals the presence of CCK peptides in rabbit cerebral cortical tissue neurons. Subcellular fractionation of rat cerebral cortical tissue demonstrates that CCK immunoreactivity is concentrated in the pellet identified by electron microscopy to contain a high proportion of synaptic vesicles. A converting enzyme that differs from trypsin has been partially purified from canine and porcine cerebral cortical extracts. It converts porcine CCK to smaller immunoreactive forms, but fails to convert big gastrin to heptadecapeptide gastrin. This enzyme differs from trypsin not only in substrate specificity but also in several physicochemical properties. Cerebral cortical extracts from hyperphagic ob/ob mice have strikingly lower contents of CCK than those from their lean littermates and other normal mice. These studies taken together are consistent with a role for CCK as a neurotransmitter involved in the overall regulation of appetite.


Neurohypophyseal principles and memory.

The neurohypophyseal hormones vasopressin and oxytocin modulate memory processes. Vasopressin facilitates, while oxytocin attenuates memory consolidation and retrieval. These influences are located in different regions of the molecules. Thus, the neurohypophyseal hormones act as precursor molecules for neuropeptides involved in memory processes. The covalent ring structures of both vasopressin and oxytocin mainly affect consolidation; the linear parts, retrieval processes; while nearly the whole oxytocin or vasotocin molecule is needed for attenuation of consolidation and retrieval. Regional studies, utilizing microdissection techniques in combination with a sensitive radioenzymatic catecholamine assay, revealed a distinct pattern of effects on cerebral alpha-methyl-p-tyrosine methylester-induced catecholamine disappearance following intraventricular vasopressin administration in limbic midbrain structures. In situations in which the amount of bioavailable vasopressin in the brain is absent, as is the case in the Brattleboro rat with hereditary diabetes insipidus, or neutralized in normal Wistar rats following the intraventricular administration of antivasopressin serum, regional catecholamine disappearance in most cases is altered in a direction opposite to that observed after intracerebroventricular vasopressin administration. These results indicate that vasopressin modulates memory processes by modulation of neurotransmission in distinct catecholamine systems. Recent experiments suggest that the influence of vasopressin on memory consolidation is mediated by the dorsal noradrenergic bundle via terminal regions of this bundle.


[Changes in the millivolt potential of brain structures during micropolarization influencing trace phenomena].

In chronic experiments on monkeys and cats, the effects of intracerebral micropolarization modulating memory processes, on the mV potential of cerebral structures, were studied. A connection was revealed between trace fixing and processes of systemic kindling on the one hand, and the following stabilizing of mV potential, on the other hand. The data obtained suggest that the distant changes of the mV potential reflect a general "tuning" of cerebral systems, are realized by means of specialized regulatory neuronal networks and connected with shifts in metabolic processes.


[Effect of parenterally administered amino acids and protein hydrolysate on the electrical activity of brain structures].

Glycin, glutamic acid or casein hydrolysate induced high frequency and high voltage electrical waves in the brain-stem RF and often in the lateral hypothalamic nucleus and cortex. These changes were more obvious during feeding of the dogs. Sham feeding and parenteral administration of glucose or 0.9% solution of NaCl evoked responses different from the above ones. Gastric secretion stimulated by i.v. administration of nitrous substances by food was not directly related to the above responses either. The impulses responsible for the secretion seem to arise at another level of the brain.


Specific binding of 20-hydroxyecdysone to nuclei of imaginal discs of Drosophila melanogaster.

Specific binding of the insect steroid hormone 20-hydroxyecdysone to imaginal discs of Drosophila melanogaster has been investigated. Evidence is presented showing that most of the specific binding is located in the nuclear fraction at the time changes in gene function are observed. Nuclear binding is high affinity, analog specific, apparently saturable, and unaffected by inhibitors of RNA and protein synthesis. The association kinetics of nuclear binding are very similar to those of specific binding in whole cells. Specific binding to whole discs and to disc nuclei is temperature-dependent, but equal levels of nuclear binding are achieved after 1 h at 25 degrees C and 8 h at 0-4 degrees C. There is little or no lag in the nuclear location of specific binding at either temperature. The biochemical properties of the specific nuclear binding are consistent with the involvement of these sites in the hormone detection and response system mediating imaginal disc morphogenesis.


Ontogeny of the visual evoked response in the stump-tailed macaque.

Visual evoked responses (VER's) of stump-tailed macaques were studied from birth to 80 weeks in an attempt to establish the utility of this species as a model of human neurophysiological development. Although human subjects and monkeys share a unique complexity of the VER at birth, the postnatal development of their VER's does not appear to follow a parallel sequence. The relatively dynamic nature of the VER during the 1st few weeks in a monkey's life may limit the usefulness of this species as a model of human development. The rapid changes in the VER of the developing monkey and the observation that these changes continue beyond 2 years of age should be considered in studies of the VER in which repeated measures are obtained over a prolonged period of time.


Auditory evoked potentials and auditory behavior following prenatal and perinatal asphyxia in rhesus monkeys.

Two types of asphyxia were studied in monkeys, total asphyxia during mid-pregnancy (94--98 days gestation) and combined partial and total axphyxia at term (165 days gestation). Auditory evoked potentials and the acquisition of 2 auditory discrimination tasks were studied in asphyxiated animals as well as in group of controls. The brains of all asphyxiates were examined histologically. No auditory discrimination deficit was found in the asphyxiated animals; however, the auditory evoked potentials differentiated between control and asphyxiated animals, especially those with verified inferior colliculus damage.


Ligation or external fistulation of the common bile duct in the rat. II. Intestinal disaccharidase activities.

72 h after ligation or external fistulation of the common duct the activities of maltase, sucrase and lactase in the homogenate of the small intestinal mucosa of the rat were determined. The experiments were performed in connexion with intestinal perfusion studies, and the disaccharidase activities were measured in unperfused intestinal segments as well as in intestinal loops which had previously been perfused with a sucrose-containing solution. After bile duct ligation, the sucrase and maltase activities in a previously perfused intestinal loop were not different from those in sham-operated animals, the lactase activity was diminished. In a nonperfused segment, the sucrase activity was greater, the maltase activity was unchanged, and the lactase activity was lower than in control animals. After bile duct fistulation, the sucrase, maltase and lactase activities in a perfused segment were lower than in sham-operated rats. In a nonperfused loop, the sucrase activity was greater, the maltase activity was unchanged, and the lactase activity was lower then in the corresponding control group. These data suggest that bile is a factor which influences the total mucosal disaccharidase activities, and, probably, the intracellular enzyme distribution.


Jejunal diverticulosis and chronic pneumoperitoneum.

A unique case of pneumoperitoneum, without peritonitis or perforation, associated with jejunal diverticulosis is presented. Pneumoperitoneum is documented over the course of many years, with recurrence after partial small bowel resection. Jejunal diverticulosis is one of the leading gastrointestinal causes of pneumoperitoneum without peritonitis or surgery. The distended diverticular mucosa may function as a semipermeable membrane allowing transmural gas equilibration.


A mutational analysis of the triplo-lethal region of Drosophila melanogaster.

The extensive analysis of the impact of segmental aneuploidy by Lindsley et al. (1972) showed that there are relatively few haplo-lethal loci in the genome and that, with one exception, all loci are triplo-viable. The exceptional locus, which lies in salivary gland chromosome region 83D-E, is associated with lethality when present in either one or three doses in an otherwise diploid individual (Denell 1976). The genetic nature of the phenomenon has been studied by examining the rates of induction, by ionizing radiation and chemical mutagens, of mutations affecting the dose-sensitive behavior. For both types of mutagens, the frequency of inactivation of the locus is relatively low, and a high proportion of such mutations is associated with chromosomal deficiencies. These data indicate that the locus is infrequently and perhaps never inactivated by a DNA base-pair substitution and thus that the triplo-lethal phenomenon is not associated with a "typical" structural gene. It is possible that the triplo-lethal locus is very small, is reiterated or otherwise complex or is functionally insensitive to base-pair substitutions. The result that all mutations that complement a duplication of the triplo-lethal locus are lethal in heterozygous combination with a normal third chromosome argues that triplo- and haplo-lethality are concomitants of the same phenomenon. Salivary gland chromosome analysis of newly induced deficiencies and duplications localizes the locus to 83D4,5--83E1,2, and further cytogenetic mapipulation shows that the dose-sensitive behavior is independent of the position of the locus in the genome.


Heterochromatic effects on the behavior of reversed acrocentric compound-X chromosomes in Drosophila melanogaster.

Previous studies of reversed acrocentric compound-X chromosomes suggested peculiar influences of heterochromatin on both the synthesis and meiotic behavior of such compunds. It seemed, with respect to synthesis, that the long arm of the Y chromosome on an X.Y(L) chromosome was necessary in order for the heterochromatic exchange giving rise to reversed acrocentrics to occur, even though Y(L) itself did not participate in the compound-generating event. With respect to behavior, the resulting compounds appeared, presumably as a consequence of their singular generation, to contain an interstitial heterochromatic region that caused the distribution of exchanges between the elements of the compound to be abnormal (many zero and two-exchange tetrads with few, if any, single-exchange tetrads). Removing the intersititial heterochromatin (or, curiously, appending Y(L) as a second arm of the compound) eliminated the recombinational anomalies and resulted in typical tetrad distributions.--We provide evidence that these peculiarities, while presumably real, were likely the consequence of a special X.Y(L) chromosome that was used to synthesize the reversed acrocentrics examined in the early studies and are not general properties of either reversed acrocentric compounds or of interstitial heterochromatin. However, we show that specific heterochromatic regions do, in fact, profoundly influence the behavior of (apparently all) reversed acrocentric compound-X chromosomes. In particular, we demonstrate that specific portions of the Y chromosome and of the basal X-chromosome heterochromatin, when present as homologs for reversed acrocentric compounds, markedly and coordinately increase both the frequency of exchange between the elements of the compound and the fertility (egg production) of compound-bearing females. It is, we suppose, some aspect of this heterochromatic effect, produced by the special X.Y(L) chromosome, that caused the earlier-analyzed compounds to exhibit the observed anomalies.


An attempt to select for increased longevity in Drosophila melanogaster.

Eight generations of selection towards a higher longevity were made in a wild strain of Drosophila melanogaster. Two control lines were also observed. Absolutely no response to selection was obtained whilst a major increase in longevity occurred between F2 and F4 in the three lines under observation. It is shown that the major increase in longevity is due neither to genetic drift, nor to changes in classical environmental conditions. The absence of response to selection is demonstrated to be due neither to a too low selection differential, nor to the absence of genetic variability in the strain, nor to inaccuracy in the measurements, nor to recurrent reproduction at an old age. The impossibility to select towards a higher longevity and the total absence of relation between parental and offspring longevities demonstrate that the very large phenotypic variability displayed by longevity in wild strains of D. melanogaster does not depend on a precise set of specific genes or polygenes with additive action. The results are briefly discussed in relation with inbreeding depression and heterosis for longevity and with similar results obtained in experiments of selection for duration of development.


2-Deoxy-D-lyxo-hexonic acid from 2-deoxy-D-lyxo-hexose by Pseudomonas aeruginosa fermentation.

Aerobic fermentation of media or solutions containing 2-deoxy-D-lyxo-hexose and calcium carbonate by bacterial cells capable of oxidizing aldoses to aldonic acids was used to prepare 2-deoxy-D-lyxo-hexonic acid; the acid was isolated in a 62% yield in the form of its 1,4-lactone.


The differential effect of insulin in vivo on the peripheral utilization of glucose and ketone bodies in the rat.

This in vivo study assessed the immediate effects of insulin on glucose and ketone body utilization in the fed, fasted, and diabetic ketoacidotic rat. The experimental design consisted of the functional removal of the liver (the site of glucose and ketone body production) and the pancreas from the anesthetized animals. This surgical procedure permitted the assessment of the effect of exogenously administered insulin on the rate of both glucose and ketone body utilization by peripheral tissues. Insulin exerted hypoglycemic activity in all three metabolic states studied. This hypoglycemic activity contrasted to the lack of demonstrable effect of this hormone on ketone body uptake by peripheral tissues. It was concluded that in the rat, the immediate effect of insulin, i.e. within 30 minutes, was to exert hypoglycemic activity without simultaneous hypoketoniemic activity.


Kinetic analysis of plasma TSH dynamics after TRH stimulation.

Kinetic analysis of the time course of plasma TSH after TRH stimulation was performed by means of a single compartment model with first order input. This kinetic model showed satisfactory fit to the data, and was found to be useful enough for the characterization of plasma TSH dynamics. In endocrinologically normal short children, the amount of TSH release per unit volume of distribution space (Q0/V), the rate constant for the TSH release (alpha), and the rate constant for TSH elimination (beta) were averaged 23.4 microU/ml, 6.981 hr-1 and 0.813 hr-1, respectively. Elevated Q0/V values with lowered alpha and beta were obtained in the hypothyroid children. Variable results, with the exception of low alpha values, were obtained in the children with pituitary dwarfism.


Primary lymphomas of the small intestine in Iraq: a pathological study of 145 cases.

The histopathology of 145 malignant lymphomas of the small intestine in Iraq have been studied and results compared with the clinical and immunological findings. The most common pathology was an intense mucosal lymphoplasmacytic proliferation effacing the villi and crypts partially or completely. This was either 'pure', usually of mature plasma cells limited to the lamina propria or associated with a fullblown lymphoplasmacytic lymphoma, almost always of the upper small intestine. The syndrome presented as abdominal pain, chronic diarrhoea, clubbing and, sometimes, the serological demonstration of alpha heavy chains. Other types of lymphomas were associated with 'non-specific' mucosal inflammation or follicular lymphoid hyperplasia. They were either lymphocytic, plasmacytic or lymphoblastic with 'starry sky' histiocytic reaction, representing distinct clinicopathological entities unrelated to 'alpha heavy chain disease'. Hodgkin's disease was extremely rare in this series.


Community HMO built by Ford.

Ford Motor Company believes HMOs promote competition that cuts health care costs for employers, employees, and communities/Its development of a Detroit HMO is described here.


Comparisons show construction management's benefits.

Analysis of competitive bid, design-build, and construction management approaches shows that construction management offers owners substantial advantages regarding project cost and quality and substantial involvement and control throughout the process.


XY gonadal dysgenesis and the H-Y antigen. Report on 12 cases.

H-Y antigen was determined in 12 patients affected by XY gonadal dysgenesis. Of these, three proved to be H-Y negative, and nine, including two sisters, were H-Y positive; two of the unrelated positive cases exhibited a reduced antigen titer. Therefore, this clinical condition must be genetically heterogeneous. It is assumed that in the negative cases and possibly in those with reduced antigen titer, the H-Y generating system is affected by mutation, while in the regular positive cases the target cells are unable to respond due to a defect of the gonad-specific H-Y antigen receptor.


Partial trisomy 6p.

A case of trisomy 6p21 leads to 6pter resulting from a maternal balanced t(2;6)(p25;p21) translocation is reported. The main clinical abnormalities were psychomotor retardation, hypotrophy, blepharophimosis, nystagmus, high nasal bridge, small mouth, sacral dimple, and systolic murmur. Other anomalies might have been due to partial 2p monosomy. Comparison with seven other cases of trisomy 6p allowed the delineation of a clinical entity. Direct proof of the localization of HLA genes was given by the presence of three haplotypes in the index patient.


Familial XX true hermaphroditism and the H-Y antigen.

Two 46,XX sibs, one of female, one of male gender, and both with ambiguous external genitalia and ovotestis, were H-Y positive. The mother was H-Y negative. It is assumed that the underlying mutation was transmitted by the father, resulting in an autosomal dominant mode of inheritance. The common origin and the nature of the mutation leading to XX sex reversal are discussed.


An ultramicrochemical test for mycoplasmal contamination of cultured cells.

A sensitive ultramicrochemical enzyme test for mycoplasmal contamination of cultured cells, based on the determination of the activity of adenosine phosphorylase, is described. The test was performed by assaying the enzymatic conversion of [8-14C]adenine and ribose-1-phosphate to [8-14C]adenosine by incubating a plastic leaflet carrying a counted number of cells (1 to 10). These leaflets were isolated from the bottom of the same plastic film dish in which the cells were cultured for experimental or diagnostic purposes, e.g. prenatal diagnosis or inborn errors of metabolism. The present test should be several 1000-fold more sensitive than the originally reported enzymatic method because (a) the adenosine-phosphorylase reaction is measured in the nucleoside forming direction which is by far the most active; and (b) the assay is performed with the cells and not with the culture medium. The latter is of special importance for the detection of those low-grade contamination in which most of the mycoplasma particles are attached to cell membranes.


[Plasma protein levels during postoperative parenteral feeding].

In 58 adult intensive care patients, the concentration changes of some plasma proteins and of the immunoglobulins IgA, IgG and IgM were examined postoperatively under parenteral feeding. In three groups of patients with different operations (trepanation, gastrectomy, vascular surgery), the initial and subsequent values were not the same. A comparison with simultaneous nitrogen balances showed no complete agreement. Transferrin, retinol-binding protein and prealbumin seem to be suitable parameters for the measurement of catabolism.


[The effect of combined parenteral-peroral nutrition on the protein status of undernourished elderly patients].

Eight elderly undernourished patients with bronchopneumonia were admitted into the clinic for treatment as well as intentive, combined parenteral-peroral nutrition. The improved protein status achieved was evidenced by a significant increase in the serum concentration of total protein, prealbumin and retinol-binding protein. There was a significant decrease of haptoglobin in all patients, measured in the upper normal range, even though it was extremely high at the onset of therapy due to the inflammatory process. These findings emphasize the influence of consequent nutritional therapy in the treatment of pneumonia, especially for elderly patients.


[Physiologic-chemical parameters during postoperative infusions].

Individual parenteral alimentation with infusions of combined carbohydrates and amino-acids produced no clinical side effects, however, the electrolyte, acid-base and phosphate balance had to be observed strictly.


Behavior of Escherichia coli K antigens K88ab, K88ac, and K88ad in immunoelectrophoresis, double diffusion, and hemagglutination.

Porcine enteropathogenic Escherichia coli strains were found to possess a variant of the K88 antigen provisionally termed K88ad. We propose to include this antigen into the international E. coli typing scheme. Ultrasonic extracts of field strains of E. coli possessing the K88ab, K88ac, or K88ad antigen and their E. coli K-12 K88+ transconjugants showed a specific K88 precipitation line in immunoelectrophoresis and double diffusion only when grown at 37 degrees C, but not when grown at 18 degrees C. By using agarose gels, K88ab, K88ac, and K88ad antigens showed anodic mobility in immunoelectrophoresis. When using Difco Noble agar gels, K88ad was not mobile or anodic, K88ab was cathodic; K88ac of 17 strains was cathodic and of 24 strains was anodic. The immunoelectrophoretic behavior of a K88 antigen (K88ab, K88ac, or K88ad) did not alter after transfer of the corresponding plasmid to E. coli K-12. Anodic and cathodic K88ac antigens could not be distinguished serologically. The differences between the results obtained in Noble agar gels and agarose gels are due to electro-endosmotic flow. We describe a procedure which increases the detection level of K88+ transconjugants in a mating mixture. It is based on the specific mannose-resistant attachment of K88+ cells to guinea pig erythrocytes.


Interaction of polymorphonuclear leukocytes with smooth and rough strains of Brucella abortus.

The bactericidal activity of guinea pig and human polymorphonuclear leukocytes (PMNs) against a smooth-intermediate strain (45/0) and a rough strain (45/20) of Brucella abortus has been examined. After incubation for 120 min, guinea pig PMNs incubated with either the smooth strain 45/0 or the rough strain 45/20 exhibited no bactericidal activity against the former and caused only a 34% decrease in viability of the latter. Human PMNs were more bactericidal than guinea pig PMNs to both strains; however, the killing of strain 45/20 by human PMNs was less than that observed in control experiments with S. aureus strain 502A. Both strains of B. abortus readily associated with guinea pig and human PMNs, and the bacteria were apparently ingested without stimulation of the hexose monophosphate pathway. Lysates (10 micrograms/ml, pH 5.5), prepared from guinea pig or human granules, were not particularly toxic to either strain unless supplemented with H2O2 and a halide (I- or Cl-). An oxygen-dependent killing system appeared to be lethal against both strains of B. abortus, with I- being more active than Cl- in the presence of H2O2 and granule lysate. The data suggest that degranulation after ingestion of Brucella by phagocytes does not occur due to the lack of a proper stimulus or possibly the baccilli actively inhibit the degranulation process thereby protecting the microbe from killing systems normally effective against extracellular parasites.


Studies on gonococcus infection. XVIII. 125I-labeled peptide mapping of the major protein of the gonococcal cell wall outer membrane.

The major outer membrane proteins from 10 gonococcal strains were examined after 125I-labeling of the proteins as single bands resolved by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. These 125I-proteins were then treated with either trypsin or alpha-chymotrypsin, and the resultant 125I-peptides were visualized by autoradiography after two-dimensional electrophoretic and chromatographic separation on thin-layer cellulose sheets. Several 125I-peptides were present in all the major outer membrane proteins examined. The presence and absence of additional 125I-peptides segregated the major proteins into two pattern groups. One group consisted of major outer membranes with molecular weights of 34,000 or 33,000; major proteins with molecular weights of 32,000 constituted the other group. Two beta-lactamase-producing gonococcal isolates were examined. Their major outer membrane proteins were identical in apparent molecular weights and alpha-chymotryptic 125I-peptide fingerprints; these proteins contained 125I-peptides not found in other gonococcal major proteins. No 125I-peptide differences were found among the major outer membrane proteins of strain F62 gonococci that exhibited differences in piliation and/or colony opacity characteristics.


Chemical characterization and biological properties of lipopolysaccharides isolated from smooth and rough strains of Brucella abortus.

The chemical composition and some of the biological activities of lipopolysaccharides (LPS) extracted from a smooth-intermediate strain (45/0) and a rough strain (45/20) of Brucella abortus have been examined. LPS were found in both the phenolic and aqueous extraction phases of strain 45/0, but only in the aqueous phase of 45/20. The phenolic LPS contained 9- to 16-fold-lower levels of heptose and reduced amounts of dideoxyaldoses compared with aqueous fractions. The major neutral sugars were glucose, galactose, and mannose. beta-Hydroxymyristic-acid, a common marker of enteric LPS, was not detected. Fatty acids present in highest amounts were hydroxylated and nonhydroxylated species with chain lengths of 16, 18, and 20 carbons. Only the phenolic LPS of strain 45/0 exhibited mouse lethality and a curable wasting disease; however, both phenolic and aqueous fractions caused carbohydrate depletion in mice. The toxicity of aqueous LPS could not be potentiated with Pb(OAc)4. These data, coupled with the lack of mitogenic activity for B-lymphocytes, are indicative of the unique structure-function relationships of Brucella LPS.


Surface macromolecules and virulence in intracellular parasitism: comparison of cell envelope components of smooth and rough strains of Brucella abortus.

The surface topography of whole cells and the chemical composition of cell envelopes of a smooth-intermediate strain (45/0) and a rough strain (45/20) of Brucella abortus was examined. Electron microscopy of whole cells and thin sections did not reveal any gross surface difference(s). Only minor quantitative differences were observed in total lipids, proteins, and the murein layer. However, the lipopolysaccharide composition of the two strains was quite different. Both phenol- and water-soluble lipopolysaccharide fractions were obtained from the strain of higher virulence (45/0), whereas only aqueous lipopolysaccharide could be isolated from the rough strain. In addition to being toxic, the phenol-soluble lipopolysaccharide may be a key virulence factor in intracellular survival of B. obortus within phagocytic cells.


Isolation, characterization, and biological properties of an endotoxin-like material from the gram-positive organism Listeria monocytogenes.

The bacterial component responsible for the induction of transient cold agglutinin syndrome in rabbits after intravenous injection of heat-killed Listeria monocytogenes type 4B has been purified and biologically and chemically characterized. A purified immunoglobulin M cold agglutinin was prepared from high-titer sera resulting from the immunization of rabbits with heat-killed L. monocytogenes type 4B and was subsequently used to monitor the purification of the bacterial component responsible for its induction. The bacterial component was isolated from a hot phenol-water extract of lyophilized L. monocytogenes type 4B by multiple molecular sieve chromatography. Upon chemical analysis the purified material was found to be strikingly similar in chemical composition to gram-negative lipopolysaccharide endotoxins. The material contained 15% total fatty acid (of which 50% was beta-hydroxymyristic acid), 40 to 45% neutral sugar (glucose, galactose, and rhamnose), 11.5% amino sugar, 12% uronic acid, 2.5% 2-keto-3-deoxyoctonic acid, 2% heptose, 0.87% phosphorus, and 1.6% amino acid, thereby accounting for 85 to 90% of the weight of the component. Electron micrographs of the purified material were similar to those of lipopolysaccharide preparations from gram-negative organisms. The purified material exist in aqueous solutions as large aggregates, but can be dissociated into a single smaller subunit (3.1S) by dialysis against sodium dodecyl sulfate buffer. The listerial component was toxic and pyrogenic to rabbits, producing symptoms typical of gram-negative endotoxins. Activity in the limulus lysate gelation assay and in the carbocyanine dye assay provides a further link of this material with classical gram-negative endotoxins.


Relationship between superoxide dismutase and pathogenic mechanisms of Listeria monocytogenes.

Listeria monocytogenes was examined for superoxide dismutase(SOD) activity. Two catalase-negative strains possessed at least twofold greater SOD activities than the catalase-positive L. monocytogenes strains examined. Growth conditions such as aeration and iron concentration influenced the specific activity of SOD obtained from cells cultured in defined media. L. monocytogenes SOD from crude extracts and after partial purification was analyzed by polyacrylamide gel electrophoresis. Iron was associated with the single band of SOD activity detected in the gels. SOD activity appeared to be primarily extracytoplasmic. Survival of organisms in a superoxide-generating medium was studied, with photoactivation of riboflavin used as the source of free radical formation. Virulent, catalase-positive L. monocytogenes strains were relatively resistant to killing in a pH 7 superoxide-containing medium. An intact-cell assay for SOD was developed, which used the superoxide-generating system and employed the superoxide-dependent oxidation of sulfite, added to the medium, and inhibition of this oxidation by SOD. Maximal SOD activites of intact cells were observed when 100 to 400 micrograms (dry weight) of viable Listeria cells per ml was added to the medium. A possible role for SOD in the pathogenesis of listeric infection is discussed.


Thymus-dependent control of host defense mechanisms against Trypanosoma cruzi infection.

Congenitally athymic homozygous (nu/nu) mice were shown to be significantly more susceptible to Trypanosoma cruzi infection than their thymus-bearing heterozygous (nu/+) littermates, as measured by increased parasitemia, mortality rate, and shortened survival time. In addition, transplantation of neonatal thymus into athymic mice reestablished normal levels of resistance to T. cruzi, i.e., comparable to those of normal littermates. These results constitute conclusive evidence that host defense mechanisms active in experimental Chagas' disease are under thymic control.


Production of exotoxin A by Pseudomonas aeruginosa in a chemically defined medium.

A defined medium was developed in which easily measured quantities of exotoxin A (PE) were produced by Pseudomonas aeruginosa PA-103. The medium contained three L-amino acids (arginine, aspartic acid, and alanine), basal and trace salts including 14 mM K2HPO4, 14 mM glucose, and 140 mM glycerol. The concentrations of amino acids which yielded most satisfactory results were 6 mM alanine, 13 mM aspartic acid, and 16 mM arginine. The identity of PE in the culture supernatant fluid was demonstrated by adenosine diphosphate-ribosyl transferase activity and by immunodiffusion with sheep antitoxin elicited with purified PE and with PE produced in Trypticase soy broth dialysate and pure PE as controls. PE production was also demonstrated by mouse lethality and passive hemagglutination. As compared to Trypticase soy broth dialysate, P. aeruginosa produced 25 to 50% PE in the defined medium. Different strains of P. aeruginosa produced PE in the defined medium in proportions relative to those in Trypticase soy broth dialysate.


Adjuvant effects of low doses of a nuclease-resistant derivative of polyinosinic acid . polycytidylic acid on antibody responses of monkeys to inactivated Venezuelan equine encephalomyelitis virus vaccine.

Polyriboinosinic.polyribocytidylic acid [poly(I).poly(C)] stabilized with poly-l-lysine and carboxymethylcellulose [poly(ICLC)] has been previously shown to be a compound with marked adjuvant activity when given in high doses with inactivated Venezuelan equine encephalomyelitis (VEE) virus vaccine. This study investigated the effects of much lower doses of poly(ICLC) on the magnitude and kinetics of the primary and secondary humoral antibody responses of rhesus monkeys to inactivated VEE virus vaccine. Monkeys given a single injection of vaccine developed very low neutralizing antibody titers, whereas those given adjuvant plus vaccine had 30- to 100-fold-higher titers which remained elevated for longer than 6 months. Low doses of poly(ICLC) given with VEE virus vaccine resulted in a profound but transient increase in priming of secondary antibody responses to the antigen. In contrast, the administration of poly-l-lysine and carboxymethylcellulose alone without the poly(I).poly(C) component of the complex had no adjuvant effect on antibody responses of monkeys to VEE virus vaccine. The temporal development of antibody by class (immunoglobulin M-immunoglobulin G) in monkeys given two injections of adjuvant-vaccine was not different from that with vaccine alone. Serial hematological and clinical chemistry determinations on monkeys given single or multiple doses of poly(ICLC) with vaccine were not different from values in monkeys given vaccine alone.


Effect of type-specific active immunization on the development and progression of experimental Pseudomonas aeruginosa endocarditis.

Rabbits with intracardiac catheters were immunized with heat-killed Pseudomonas aeruginosa or saline and challenged with either 10(9) (high inoculum) or 10(7) (low inoculum) pseudomonas. Immunization did not decrease the incidence of endocarditis when compared with controls, but it did significantly prolong survival. The longer survival of immunized rabbits after high-inoculum challenge was not due to prolongation of the course of endocarditis but to type-specific protection from early, overwhelming bacteremia. However, after low-inoculum challenge there were no early deaths and there was a significantly (P < 0.01) longer survival of immunized (17.4 days) than unimmunized (10.6 days) animals dying of endocarditis. Increased survival was associated with higher total and 2-mercaptoethanol-resistant hemagglutinating antibody titers 1 week after challenge in immunized as compared with unimmunized rabbits. Early (48 h after challenge) vegetation colonization was also significantly (P < 0.05) greater after type-specific as opposed to non-type-specific or saline immunization and low-inoculum challenge. However, whereas 67% of type-specifically immunized rabbits had colonized vegetations at 48 h, only 38.9% died with bacteremic endocarditis. Another 19.2% of immunized rabbits had vegetations colonized with > 10(5) colony-forming units of pseudomonas at elective sacrifice 2 weeks after challenge but no bacteremia; no unimmunized rabbit exhibited similar late colonization. Preexisting antibody may be important in the pathogenesis of pseudomonas endocarditis in drug addicts, and its presence may explain the subacute and often protracted course of the disease.


Assessment of protease (elastase) as a Pseudomonas aeruginosa virulence factor in experimental mouse burn infection.

The data presented indicate that in experimental Pseudomonas aeruginosa infection of mice, protease enhances the virulence of the organism. Anesthetized CBA/Lü mice were subjected to a 15-s flame burn and infected with a wild-type protease-producing strain and two of its protease-deficient mutants. The average bacterial cell mean lethal dose (LD50) of 3.8 +/- 0.3 standard deviation (log10) for mice infected with the protease-producing P. aeruginosa was at least 1 log lower than the LD50 of the protease-deficient mutants (0.02 greater than P greater than 0.01). The addition of purified protease to the infecting inoculum of protease-deficient strains reduced the LD50. Although the generation time in vitro was the same for all three bacterial strains used, there were consistently fewer viable bacteria in the blood of mice infected with protease-deficient strains than in those infected with the protease-producing strain. When a protease-deficient strain was mixed with the protease-producing wild-type strain, the number of protease-producing pseudomonas found in the blood remained constant, whereas the number of protease-deficient organisms increased, suggesting that protease contributed to the invasiveness of the organisms. The survival of mice infected with protease-producing pseudomonas was enhanced by antiprotease serum. Antiprotease serum had no effect in mice infected with protease-deficient mutants.


Protease and elastase of Pseudomonas aeruginosa: inactivation of human plasma alpha 1-proteinase inhibitor.

The present study indicates that crystalline elastase of Pseudomonas aeruginosa is a very potent inactivator of human plasma alpha 1-proteinase inhibitor, the enzyme (E) inactivated the inhibitor (I) almost completely within 1 h at 25 degrees C at a molar ratio of E/I = 1:100. The crystalline P. aeruginosa protease also inactivated the inhibitor, but 100-fold less. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that the alpha 1-proteinase inhibitor inactivated by the elastase and protease showed decreases in molecular weight of approximately 5,000 and 10,000, respectively. Regeneration of trypsin was negligible even when bovine trypsin-alpha 1-proteinase inhibitor complex (E/I = 1.0) was treated with the elastase. The affinity of alpha 1-proteinase inhibitor to trypsin was much higher than that to elastase. It was suggested that, assuming the pseudomonal proteases are produced and can inactivate alpha 1-proteinase inhibitor in vivo during pseudomonal diseases, the loss of alpha 1-proteinase inhibitor activity may permit the endogenous serine proteases to cause tissue destruction.


Pili of Neisseria meningitidis: effect of media on maintenance of piliation, characteristics of Pili, and colonial morphology.

In contrast to information in the literature which indicates that meningococci rapidly lose pili upon cultivation in vitro, we found that piliation of meningococci could be maintained in vitro for 15 or more passages. Pili were present on all eight isolates tested, whether from asymptomatic carriers or from subjects with meningococcal disease. Complete loss of piliation occurred in the same two strains on two of the three media tested. On one medium (Thayer-Martin medium with supplement B), there was partial or complete loss of pili by all strains. The optimal medium for maintaining pili was chocolate agar with 1% IsoVitaleX; 95% or more of the microorganisms of six of the eight strains tested were piliated after 15 passages in vitro, and more than 60% of the microorganisms of the other two strains were piliated. Meningococci passed on this medium generally maintained their initial density of piliation (3 to 34 pili per diplococcus). The ability to predictably cultivate piliated meningococci in vitro and to select piliated and nonpiliated clones of the same strain should allow investigation of the biochemical and immunological properties of meningococcal pili as well as their possible role in the pathogenicity of Neisseria meningitidis.


Intramuscular and/or intralumbar postexposure treatment of rabies virus-infected cynomolgus monkeys with human interferon.

From 9 to 10 of 10 cynomolgus monkeys infected with rabies street virus died of rabies about 20 days postinfection (pI). Symptoms of illness appeared 1 to 4 days before death. In an attempt to protect infected animals from the disease, human leukocyte interferon (HIF) was administered intramuscularly (i.m.) near the site of infection or into the cerebrospinal fluid between the first and second lumbar vertebrae (i.e., intralumbarly [i.l.]). Multiple HIF doses given over a period of several days proved more effective than a single HIF dose. In every experiment, i.m. HIF treatment was started 1 day pI. The best result obtained was a survival rate of 7 of 10 monkeys. The i.l. HIF administration schedules, consisting of multiple doses given over a period of at least 8 days, were started on day 3, 7, or 11 pI. Here the best result noted was the protection of 5 of 10 treated monkeys. The latest successful postexposure i.l. HIF treatment began on day 11 pI. The highest protection rate, 8 survivors of 10 treated monkeys, was achieved by a combined i.m. and i.l. HIF treatment. From these results we conclude that human patients severely bitten by rabid animals should in addition to an active immunization be i.m. and i.l. treated with HIF. Particularly, i.l. HIF administration could be effective, even when given several days pI. Whether an HIF administration starting after the appearance of clinical symptoms of rabies can help cannot be decided upon from the studies made in this monkey model. The most obvious difference between rabies in humans and cynomolgus monkeys is the duration of illness between the outbreak of the disease and death (1 to 4 days only in this animal model). It might have been due to this short period of illness that i.l. and i.m. HIF treatment at the appearance of clinical symptoms failed to help any of the monkeys treated.


Depression of the antibody response in Pseudomonas aeruginosa-injected mice.

Heat-killed Pseudomonas aeruginosa inhibit antibody response in C57BL/6 mice. The depression of this response is dependent on the dose of bacteria injected, on the time interval between microorganism injection and antigen administration, and on the nature of the antigen used. Cell transfer experiments provide evidence that suppressor cells are not operative in this model. Furthermore, the results show that P. aeruginosa induces a marked dose-dependent proliferation of spleen cells in vivo, and the in vitro targets of this proliferative effect are B lymphocytes. It is suggested that whole, heat-killed P. aeruginosa in vivo also behave as cell mitogens on B lymphocytes which, when strongly stimulated to proliferate, temporarily lose their capacity to mount a normal antibody response.


Strain differentiation of Neisseria gonorrhoeae by reverse passive hemagglutination.

A reverse passive hemagglutination test that utilizes human erythrocytes coated with antibody to gonococci was developed to distinguish differences among 11 strains of Neisseria gonorrhoeae. Different rabbits were immunized with each strain of gonococcus. Antibody was purified by passing antiserum over an immunoadsorbent column containing homologous cell walls trapped in a cross-linked polyacrylamide gel. Antibody, after absorption with N. meningitidis, was used for coating 11 individual suspensions of erythrocytes, each with antibody to one gonococcal strain. The panel of coated erythrocytes was added to microtiter trays containing dilutions of homologous bacterial lysate and lysates from 10 heterologous strains. Agglutination titers were highest with homologous lysates, although cross-reactions occurred among some heterologous lysates. Lysates of nongonococcal Neisseria species and of other genera did not agglutinate coated erythrocytes. The reverse passive hemagglutination test can be a useful procedure to distinguish differences among strains of N. gonorrhoeae.


Immunobiology and species distribution of Mycobacterium tuberculosis antigen 5.

The immunobiology and mycobacterial species distribution of immunoabsorbent affinity chromatography-purified Mycobacterium tuberculosis antigen 5 have been studied. In delayed hypersensitivity skin tests, antigen 5 was nearly equipotent with tuberculin-purified protein derivative in sensitized guinea pigs. In vitro, antigen 5 was capable of stimulating the production of migration inhibitory factor by cultured lymphocytes from sensitized guinea pigs and humans. Antigen 5 stimulated thymidine incorporation by cultured guinea pig lymphocytes but did not stimulate thymidine incorporation by cultured human lymphocytes. Although erythrocytes were readily sensitized with antigen 5 for passive hemagglutination, their use did not offer any advantage over previous hemagglutination techniques for the serodiagnosis or evaluation of patients with tuberculosis. By immunoelectrophoresis and immunodiffusion, antigen 5 was readily identified in culture filtrates of 10 strains of M. tuberculosis and M. bovis but not in those of 30 strains of 12 other myobacterial species.


Antigenic differences between extracts of actively replicating and synchronized resting cells of Mycobacterium tuberculosis.

Protein extracts were prepared from aerobically replicating cells of Mycobacterium tuberculosis and from synchronized non-replicating cells derived from the sediments of non-agitated cultures. Although both preparations share a number of antigens, the extracts of the non-replicating cells also contain antigenic components that are not shared by the replicating cells, and which can be isolated and visualized by immunoaffinity chromatography and immunoelectrophoretic techniques.


Immune and mitogenic responses by BALB/c, C3H/HeJ, and nude mice to Brucella abortus bacterin and lipopolysaccharide.

The immunogenic and mitogenic properties of Brucella abortus 1119-3 bacterin (BA) and biologically active B. abortus lipopolysaccharide (BA-LPS) were studied using normal and athymic (nude) BALB/c and C3H/HeJ mice. Although BA stimulated 2-mercaptoethanol-sensitive (2-ME-S) primary and secondary antibody responses in all mice, nude mice, in contrast to normal BALB/c and C3H/HeJ mice, did not make substantial 2-mercaptoethanol-resistant (2-ME-R) antibody responses. Similarly, all mice injected with BA-LPS made 2-ME-S primary responses, and the secondary response of thymus-bearing mice contained a substantial 2-ME-R component. Collectively, these observations suggest that although both BA and BA-LPS can stimulate thymus-independent 2-ME-S antibody synthesis, thymus-derived cells are required for optimal immune responses containing a 2-ME-R component. The antibody responses of normal BALB/c and C3H/HeJ mice to BA and BA-LPS were qualitatively and quantitatively similar. Both BA and BA-LPS were mitogenic for spleen cells from normal and nude BALB/c and C3H/HeJ mice but not for thymus cells from normal BALB/c or C3H/HeJ mice, suggesting that both preparations are B-cell mitogens.


Mechanisms of immunity in typhus infection: adoptive transfer of immunity to Rickettsia mooseri.

When nonimmune guinea pigs are inoculated intradermally (i.d.) with Rickettsia mooseri (R. typhi), the rickettsiae replicate at the site of inoculation, leading to the development of a grossly observable lesion. In contrast, guinea pigs which have recovered from R. mooseri infection are resistant to challenge and prevent both rickettsial growth and the formation of lesions. To study the mechanisms of this immunity, sera or splenic cells collected from nonimmune or immune guinea pigs were inoculated separetely into nonimmune recipients. Splenic cells collected from immune donors protected R. mooseri-naive recipients from i.d. challenge as measured by control of rickettsial growth and by prevention of development of lesions at i.d. sites of inoculation. In contrast, serum from immune and nonimmune doners failed to protect nonimmune recipients by either criterion.


Inhibitory effect of Pseudomonas aeruginosa on the phagacytic and killing activities of rabbit polymorphonuclear leukocytes: purification and characterization of an inhibitor of polymorphonuclear leukocyte function.

A clinically isolated strain of polymorphonuclear leukocyte (PMN)-resistant Pseudomonas was found to produce an extracellular substance (PMN inhibitor) that inhibits the phagocytic and killing activities of PMN. The PMN inhibitor was purified from culture filtrates by precipitation with (NH4)2SO4 and chromatography on phosphocellulose, diethylaminoethyl-cellulose, and Sephadex G-100. The preparation was homogenous as judged by disc gel electrophoresis. The purified PMN inhibitor appeared to be a protein with a molecular weight of approximately 65,000 that was inactivated by heating and by exposure to a proteolytic enzyme.


Inhibitory effect of Pseudomonas aeruginosa on the phagocytic and killing activity of rabbit polymorphonuclear leukocytes: mechanisms of action of a polymorphonuclear leukocyte inhibitor.

The polymorphonuclear leukocyte (PMN) inhibitor isolated from a strain of Pseudomonas aeruginosa which is resistant to the phagocytic and killing activities of rabbit PMN inhibited migration of PMN and engulfment of latex particles by PMN. In studies of the bactericidal metabolism of PMN, the PMN inhibitor did not inhibit the intracellular activity and extracellular release of lysosomal enzymes. However, the PMN inhibitor caused a decrease of Nitro Blue Tetrazolium reduction. The PMN inhibitor had a cytotoxic effect on PMN and inhibited [14C]tyrosine uptake in intact PMN inhibitor had no inhibitory effect on protein synthesis in cell extracts.


Immunological cross-reactivity of oral non-streptococcal bacteria with mammalian tissue.

The presence of cross-reacting antigens between oral non-steptococcal bacteria and human and monkey tissue was investigated by indirect immunofluorescence. Rabbit antisera, prepared against 22 oral bacteria, were incubated with cryostatcut sections of heart, skeletal muscle, brain cord, liver, kidney, and skin. A cell wall antigen of Lactobacillus casei was shared with neuroglial brain cells, and an antigenic component of Propionibacterium acnes was shared with kidney glomeruli. Tissue-reactive antibodies were absorbed from the sera with preparations of both the homologous bacterium and tissue fractions.


Neisseria meningitidis infection in mice: influence of iron, variations in virulence among strains, and pathology.

The influence of iron on Neisseria meningitidis infection in C-57 mice was examined. Iron sulfate, ferric ammonium citrate, and iron sorbitol citrate all proved to be too toxic for use as infection-enhancing agents. Iron dextran displayed an extremely low toxicity, enhanced infection in a dose-dependent manner, and resulted in infection enhancement factors approaching 10(9) for virulent strains of N. meningitidis. Fatal iron dextran-enhanced infection was shown to be reversible by in vivo chelation of iron. Virulent strains of N. meningitidis produced symptoms of infection and pathological lesions in mice both with and without iron pretreatment, but an avirulent strain failed to produce symptoms of infection or pathological lesions, regardless of iron administration. Iron dextran-enhanced infection in mice proved to be a useful model for the examination of virulence of various N. meningitidis strains. All of 9 isolates from clinical disease possessed virulence, whereas only 3 of 10 isolates from carriers possessed virulence, when examined by using this model.


Methods of assessing the cost-effectiveness of caries preventive agents and procedures.

Before public finance is committed to a particular public health measure it is essential that the project should be analytically evaluated. Cost-benefit analysis is one method of choosing between alternative programmes. It suffers from the disadvantage that, while costs can be accurately assessed, the benefit to an individual of freedom from pain, discomfort or inconvenience cannot be simply expressed in monetary terms. Such benefits may therefore be omitted from calculations of cost-benefit and a programme with valuable indirect or intangible benefits may not receive adequate consideration in competition with other alternatives. Futhermore, since benefits may only accrue some time after expenditure has been incurred, inflation distorts the significance of cost-benefit calculations. Cost-effectiveness analysis is an alternative method which enables one to determine the least expensive of several alternative methods of achieving a stated objective. The application of these concepts to preventive programmes against dental caries is described. Distinction must be made between the effectiveness of preventive measures during controlled clinical trials on limited numbers of subjects and their value when applied under field conditions to the whole community. Detailed comparisons are made between various methods of the application of fluorides caries prevention by community fluoridation water supply, school water fluoridation and topical application of fluorides. It is concluded that while completely accurate and valid analyses of cost-effectiveness are not possible, they do enable dentistry to view its activities more objectively and to indentify the real issues which should affect future decisions.


The benefit of preventive procedures for high risk groups.

The clinical effectiveness of many caries prophylactic agents has been demonstrated but their public health value questioned from the viewpoint of economic efficiency. However, some groups within the population may have enhanced response to certain agents and for these subjects a more acceptable cost-value situation may occur. The effectiveness of agents may be measured by the extent to which they reduce operative treatment need. Therefore by costing treatment carried out in both groups in a clinical trial and adding, for the test group, the cost of prevention, the cost effectiveness of treatment plus prevention compared with treatment alone can be investigated. A computer was programmed to estimate from DMFS data, maintenance treatment carried out during clinical trials and that needed at the end to render subjects free of caries. Treatment was costed on the Resource Related Index. In an examination of two experimental clinical trials among adolescents it was found that supervised daily brushing in school with MFP dentifrice produced a 25 per cent reduction in DMFS over three years, but cost six and a half times as much as the operative treatment saved. However, for a high risk group of girls the cost was only two and a half times as much. When APF topical applications by hygienists were added to the same brushing programme it became even less economically efficient. Neither experimental programme was cost-effective for any group unless a weighting factor was introduced to take account of the desirablity of a sound as opposed to a filled tooth.


Cost-effectiveness considerations in planning a preventive dental programme for British Columbia.

The Government of British Columbia, Canada, with organized dentistry, in 1974, sponsored research towards the introduction of a comprehensive children's dental programme. Dental care was at that time primarily provided by private practitioners on a personal fee-for-service basis, which system was working close to capacity. Educational and preventive dental programmes in school and health centres were sponsored by governments. Utilization of treatment services by children was estimated at a maximum of 60 per cent per annum. For the improvement of overall dental health, it was adjudged this should be at least 90 per cent. Approximately 45 per cent of children's treatment was related to dental caries. Four possible dental care delivery systems were costed. It was essential that the comprehensive programmed include proven anti-cariogenic measures and that they be the most effective in cost and in the utilization of professional personnel. Techniques for measurement of effectiveness were reviewed. Using a modified Davies cost-benefit ratio, four professionally applied and four self-administered topical fluoride systems were compared. The Knutson-Szwejda technique scored highest when used by community dental health programmes. In a private practice system or in large paediatric clinics the annual application of acidulated phosphate fluoride would be preferable. In British Columbia, experience has indicated problems with continuing school cooperation in mouth rinse programmes. Statistical proof of the effectiveness of "brush-in" programmes was adjudged as inconclusive but hopeful.


Some factors affecting the long-term performance of glutaraldehyde-crosslinked heteroprostheses.

Crosslinked proteins undergo degradation in the physiological environment. Recent cumulative evidence with glutaraldehyde-crosslinked xenograft heart valves emphasizes the fact that caution is in order, despite the generally good performance of these valves in comparison to early formaldehyde-crosslinked prostheses. Glutaraldehyde involves complex chemistry yielding heterogeneous crosslinks with respect to the nature and number of crosslinks with proteins and mucopolysaccharides, all of which contribute significantly to physical and biological performance.


Cell-mediated mutagenesis in cultured Chinese hamster cells by polycyclic hydrocarbons: mutagenicity and DNA reaction related to carcinogenicity in a series of compounds.

Three polycyclic hydrocarbons, benz(a)anthracene, 3-methylcholanthrene and 7,12-dimethylbenz(a)anthracene, have been studied in a cell-mediated mutagenesis system using BHK 21 cells to metabolize the hydrocarbons and V-79 cells as targets for detecting induced cytotoxicity and mutation. In large-scale experiments, the DNA of V-79 cells was analyzed by column chromatography to determine the nature and true extent of reaction of hydrocarbons with dexoyribonucleosides. Products with DNA formed by the two carcinogenic compounds were qualitatively very similar to those reported to occur in vivo and in primary cell cultures. Binding indices were calculated from the tritium content of DNA-hydrocarbon products, related to overall metabolism, for these two compounds together with benzo(a)pyrene and 7-methylbenz(a)anthracene using data from a previous study. These values reflected differences in carcinogenic potency between the compounds. Induced mutation frequencies were related to the extent of DNA reaction with each compound. At equivalent extents of DNA reaction with hydrocarbon products, levels of induced mutation were not significantly different.


Intraocular pressure of rhesus monkey (Macaca mulatta). I. An initial survey of two free-breeding colonies.

As part of an ophthalmic and anthropometric survey of two free-breeding rhesus monkey (Macaca mulatta) populations, intraocular pressure (IOP) of 114 animals was measured under ketamine catalepsia with the use of a floating-tip pneumatonometer. The mean IOP of the 102 animals included in the main analyses was 14.9 +/- 2.1 (S.D.) mm Hg. The age distribution of animals in this sample ranged from 7 months to 21 years and reflected reasonably well the estimated age distribution in the total population (approximately 1600 macaques). Since ketamine does not have a barbiturate-like effect on IOP, this value can be regarded as a good estimate of the normal IOP of rhesus monkeys. No significant differences were found between left and right eyes nor between males and females. However, the mean IOP of infants and juveniles (7 months to 3 years) was significantly higher (15.7 +/- 2.0 mm Hg; n = 33) than that of young adult and adult rhesus monkeys (14.5 +/- 2.0; n = 69). The IOP of young animals (less than or equal to 6 years) showed a decline between 9 A.M. and 2 P.M., whereas the IOPs of older animals showed only small fluctuations between 8 A.M. and 5 P.M. This study shows that the normal IOP of macaques is remarkably similar to that of humans and demonstrates the fesibility of surveying IOP in free-ranging primates.


Evidence of a high-activity C type of carbonic anhydrase in human ciliary processes.

Carbonic anhydrase activity was found in the ciliary process of fresh human donor eyes, originating from an enzyme antigenically similar to the erythrocyte high-activity isoenzyme HCA C. It was sensitive to inhibition by acetazolamide and resistant to inhibition by halides like HCA C. The enzyme is probably identical with HCA C. Its tissue concentration was one fifth to one tenth of that in the human kidney. The erythrocyte low-activity isoenzyme HCA B was also found in the processes as a contaminant.


The transport of para-aminohippuric acid by the ciliary body and by the iris of the primate eye.

Para-aminohippuric acid (PAH) accumulates against a concentration gradient in the ciliary body and independently in the iris of the rhesus monkey eye. This accumulation is inhibited by incubation of 0 degrees C and shows saturation kinetics in both tissues. Cyanide, ouabain, dinitrophenol, iodopyracet, and probenecid effectively depress PAH uptake in both tissues, but anaerobic incubation conditions have little effect on uptake in either tissue. The washout of preaccumulated PAH occurs 2.5 times faster from the iris than from the ciliary body. The effects on washout of 10(-4)M PAH, 0 degrees C, and 10(-5)M dinitrophenol are consistent with washout occurring by a diffusional mechanism in both tissues, with some reaccumulation occurring in the ciliary body only. In addition, nonsaturable uptake of PAH, studied in both tissues under high PAH concentrations, also occurs significantly faster in the iris than in the ciliary body. The kinetic analysis of active PAH uptake in both tissues is discussed in terms of initial uptake and in terms of a steady-state model. This steady-state model compensates for some technical problems in applying in vitro incubation techniques to primate tissues and also includes a correction for the additional exchange processes that affect the two tissues differently. Results of the kinetic analysis suggest that, at least to an order of magnitude, iris uptake is significant with respect to ciliary body uptake.


Cholic acid accumulation by the ciliary body and by the iris of the primate eye.

Cholic acid accumulates in both the ciliary body and the iris of the primate eye during in vitro incubations at 37 degrees C for 1 hr. Incubation at 0 degrees C depresses uptake in both tissues. The washout of preaccumulated cholic acid occurs some 3.4 times faster from the iris than from the ciliary body. The mechanism of cholic acid accumulation in both tissues is less sensitive to inhibition by high iodipamide concentrations and also is less sensitive to inhibition by high hippurate concentrations than the mechanism of p-aminohippurate (PAH) accumulation. Therefore, although overlap may exist, the cholic acid--uptake mechanism differs from the PAH-uptake mechanism in both the primate ciliary body and the primate iris.


Identification of isoenzyme C as the principal carbonic anhydrase in human ciliary processes.

Carbonic anhydrase was extracted from the excised processes of the ciliary bodies of 10 pairs of enucleated human eyes, and the isoenzyme composition was assayed by measuring the degree of inhibition produced by acetazolamide at two standard concentrations. Also, the effect of incubating with iodoacetate was determined in two pairs of these eyes. Only isoenzyme C was detected. Accordingly, it seems that differences in reduction of intraocular pressure that are common among patients treated for glaucoma with systemic carbonic anhydrase inhibitors, despite uniform serum concentrations, are not attributable to interindividual variation of carbonic anhydrase isoenzymes in the ciliary processes.


Aqueous humor dynamics following total iridectomy in the cynomolgus monkey.

Twenty-two cynomolgus monkeys underwent unilateral total iridectomy in vivo. Several weeks to several months postoperatively, intraocular pressure (IOP) was determined bilaterally by manometry under pentobarbital anesthesia (15 monkeys), by a minified Goldmann applanation tonometer under CI-744 anesthesia (16 monkeys), and by a minified Draeger applanation tonometer under light phencyclidine catalepsia (4 monkeys). Mean IOP in aniridic eyes was about 0.3 mm Hg, or about 3%, lower than in opposite eyes. IOPs of aniridic and opposite eyes of the individual monkeys were highly correlated in all groups. In 11 monkeys, resting total outflow facility and the facility response to intravenous pilocarpine were determined 6 to 9 weeks postoperatively by two-level constant-pressure perfusion under pentobarbital anesthesia. There were no significant differences between mean resting facility, postpilocarpine facility, or facility response to pilocarpine of aniridic and opposite eyes. Resting facility, postpilocarpine facility, and facility response to pilocarpine in aniridic and opposite eyes of the individual monkeys were each highly correlated. Total iridectomy in the cynomolgus monkey apparently has little, if any, effect on IOP, outflow facility, or facility response to intravenous pilocarpine, and the iris plays little, if any, role in mediating the facility response to intravenous pilocarpine.


[Demonstration of Neisseria meningitides in the urogenital tract].

The occurence of Neisseria meningitidis in the urogenital tract is a rarity but nevertheless this may lead to a false diagnosis of gonorrhea, even when the Thayer-Martin-selective-medium is used and oxidase-reaction is performed. This is demonstrated in our case. A complete diagnosis, including sugar-fermentation, is necessary, when gram-negative diplococci are isolated from urogenital swabs. In the case Neisseria meningitidis is isolated, it is not required by law to report it to the public health authorities.


Candida osteomyelitis as a complication of parenteral nutrition in an infant. Successful treatment with flucytosine.

Hematogenous Candida osteomyelitis is described in a two-month-old infant, as a complication of Candida septicemia which occurred during a parenteral hyperalimentation regimen. Treatment with flucytosine led to full recovery. The scarcity of reports on hematogenous Candida osteomyelitis in infants, despite an increased incidence of Candida septicemia, and the non-specific symptomatology which the disease may assume in this age group, indicate the need for greater awareness of this complication. Flucytosine is an antifungal drug which can also be given by mouth and carries relatively low toxicity. We found flucytosine to be extremely effective in the treatment of disseminated infantile Candida osteomyelitis.