Clinical pharmacokinetics of ketobemidone. Its bioavailability after rectal administration

The pharmacokinetic constants and rectal bioavailability of the narcotic analgesic ketobemidone were determined in six male patients after surgery. Plasma concentrations were measured following intravenous administration of Ketogin 2 ml, containing ketobemidone chloride 10 mg, and a spasmolytic compound N,N-dimethyl-3,3-diphenyl-1-methylallylamine chloride 50 mg, and following rectal administration of one suppository of Ketogin, containing ketobemidone chloride 10 mg and the spasmolytic component 50 mg. Following intravenous administration, the disposition of ketobemidone followed a biexponential pattern with a fast distribution phase and a slower elimination phase: the plasma half-life (t1/2) was 2.42 +/- 0.41 h (m +/- SD). After rectal administration, the disposition of ketobemidone fitted a one-compartment model. The elimination half-life was 3.27 +/- 0.32 h. The mean rectal bioavailability for ketobemidone was 44% +/- 9%. The pharmacokinetic constants of the spasmolytic component, N,N-dimethyl-3,3-diphenyl-1-methylallylamine, were also determined in five of the patients, both after intravenous and after rectal administration. The plasma half-life was 3.07 +/- 0.53 h and 3.79 +/- 1.14 h, respectively. The rectal bioavailability was estimated to be 33% +/- 14%.

Clinical pharmacokinetics of bezafibrate in patients with impaired renal function

The pharmacokinetics of the new lipid-lowering drug bezafibrate has been investigated in patients with impaired renal function and hyperlipoproteinaemia. 12 patients received a single oral dose of bezafibrate 300 mg. Plasma and urine samples were collected and bezafibrate was analyzed by gas chromatography. Eight of the patients had moderately impaired renal function, with a creatinine clearance between 20 and 40 ml/min; the mean plasma half-life of bezafibrate in them was 7.8 +3.9 h (SD) and the plasma clearance was 0.03 +0.02 1/kg . h. Three of the patients had a creatinine clearance greater than 40 ml/min; in them the plasma half-life was shorter, 4.6 +1.2 h, and the plasma clearance was higher, 0.06 +0.01 1/kg . h. The slowest elimination of bezafibrate was found in a patient with a creatinine clearance of only 13 ml/min. This patient had a plasma half-life of 20.l h, which is ten times longer than has been reported in healthy volunteers. Thus, when treating hyperlipoproteinaemia in patients with impaired renal function, the dosage of bezafibrate must be individualized because of its reduced renal elimination.

Radiation myelopathy in patients treated for carcinoma of bronchus using a six fraction regime of radiotherapy

The adoption of a six-fraction regime of radiotherapy for patients with locally advanced carcinoma of the bronchus was followed by the appearance of radiation myelitis in eight cases. These were among a group of 130 patients given radiotherapy with anterior and posterior treatment fields, without shielding of the spinal cord. Radiation myelitis was found only in those where the calculated spinal-cord dose exceeded 3350 cGy (rad). The possible precipitating factors in the eight patients who suffered myelopathy were compared with those in the remaining 62 patients who also received spinal-cord doses calculated to be greater than 3350 cGy (rad). Only one difference was found--the haemoglobin concentration was significantly higher in those who suffered neuropathy compared with those who did not (P = 0.05).

Technetium 99m-plasmin: a new test for the detection of deep vein thrombosis

Deep vein thrombosis (DVT) is a common medical problem requiring early diagnosis and treatment in order to prevent serious sequelae. Currently available diagnostic acids are suboptimal, since they are either invasive (phlebography), insensitive (ultrasound), or slow (125I-fibrinogen uptake test). The 99Tcm-plasmin test was compared with the 125I-fibrinogen uptake test. The results were concordant in 38 of 40 cases studied (11 concordant positive and 27 concordant negative); a significant correlation (p < 0.05) was found. In a further 20 patients, the 99Tcm-plasmin uptake test was compared with X-ray contrast phlebography. In this series, 12 patients presented with concordant negative results, five patients with concordant positive results and three patients with a positive 99Tcm-plasmin uptake test in the presence of a negative phlebogram. Of these three cases, two presented with clinical evidence of pulmonary embolism and positive perfusion/ventilation lung scans. 99Tcm-plasmin appears to have the potential for early and rapid screening of deep-vein thrombosis 15 minutes after intravenous injection. The test is safe, quick, economic and easy to perform.

Tumour regression as a guide to prognosis: a clinical study

The response seen at the end of a course of radiotherapy in 116 patients with advanced carcinoma of the cervix included in hyperbaric oxygen trials was assessed by reduction in bulk and by histological examination. These patients have now been carefully followed for a minimum of three and a maximum of 13 years. The degree of regression, three and a maximum of 13 years. The degree of regression, as measured by reduction in bulk at the primary site, was as measured by reduction in bulk at the primary site, was found to predict closely the subsequent local tumour failure, survival and freedom from metastasis. The histological assessment also could be associated with the subsequent course, but the correlation was much weaker. In a trial of hyperbaric oxygen, where radiotherapy was given in 27 fractions to both groups, the immediate response was significantly better in the patients treated in oxygen, so predicting the result of the trial seen in long-term follow up. In the radiotherapy of carcinoma of cervix, reduction in bulk of the primary tumour at the end of treatment is a valuable prognostic index.

Phenotypic and genetic variation in the susceptibility of Haemophilus influenzae type b to antibodies to somatic antigens

Haemophilus influenzae type b (H.i.b) has been investigated with respect to phenotypic and genetic variations resulting in differential susceptibility to bactericidal antibody. Previous studies had shown that after growth in infected rats or in dialysate of rat serum, H.i.b strain Eag became more resistant to the bactericidal activity of antisomatic antibody. We now report that a similar phenotypic shift occurs when strain Eag is incubated with dialysate of human serum, that the increased resistance is to antibodies against determinants in the lipopolysaccharide not for the somatic antigens generally, and that most strains of H.i.b undergo the shift. To assess genetic differences in exposed antigens, a panel of 13 H.i.b isolates from cerebrospinal fluid were analyzed with cross-adsorbed antisera. Seven different patterns were found that could be accounted for through the variable expression of six antigens. These ranged from infrequent (found on 1:13 strains) to common (10:13 strains). At least four were somatic rather than capsular determinants; the most common (antigen 1) was contained in lipopolysaccharide. The epidemiologic relevance of the genetic variations was explored using pairs of isolates from two children who had had two documented infections with H.i.b. In both cases the isolates varied in somatic antigen expression. The strains from one patient differed in the expression of antigen 1. The isolates from the other were indistinguishable in sub-typing for the six classified antigens, but differed in the expression of an additional antigen identified by use of the patient's serum.

A general method, employing arsenazo III in liposomes, for study of calcium ionophores: results with A23187 and prostaglandins

Multilamellar (MLV) and large unilamellar (LUV) lipid vesicles (liposomes) trap the metallochromic dye arsenazo III [2,7-bis(arsonophenylazo)-1,8-dihydroxynaphthalene-3,6-disulfonic acid ] in their aqueous compartments. When ionophore A23187 was preincorporated into either MLV or LUV above 0.001 mol%, addition of Ca to the outside of liposomes produced spectral shifts characteristic of the Ca . AIII2 complex. The method permitted detection of two molecules of A23187 per liposome. Liposomes with A23187 were permselective: divalent cations were translocated in the order Mn greater than Ca greater than Sr greater than Mg congruent to Ba. Because prostaglandins (PGs) may act as Ca ionophores, we have incorporated into MLVs and LUVs stable prostaglandins (PGE2, PGI2, PGB1), endoperoxide analogs, and a water-soluble, polymeric derivative of PGB1:PGBx. None acted as ionophore. In contrast, when added to the outside of preformed MLV or LUV, PGBx, at concentrations above 1 micro M, provoked permselective uptake of Ca equivalent to that induced by 10 nM A23187. These studies demonstrate not only that liposomes containing arsenazo III may be employed in a sensitive asssay for agents that translocate divalent cations, but that a water-soluble derivative of a naturally occurring fatty acid, PGBx, is a potent ionophore.

Clinical pharmacokinetics and oral bioavailability of ketobemidone

The basic pharmacokinetics and oral bioavailability of ketobenmidone have been studied in 6 patients after surgery. Plasma concentrations were first determined following intravenous administration of Ketogin 2 ml, containing ketobemidone chloride 10 mg and the spasmolytic N,N-dimethyl-3,3-diphenyl-1-methylallylamine chloride 50 mg, and then, on the second postoperative day, following oral administration of 2 tablets of Ketogin, each containing ketobemidone chloride 5 mg and the spasmolytic agent 25 mg. The average oral bioavailability of ketobemiodone was 34% +/- 16% (SD, n = 6). The mean plasma half-life of elimination (t1/2 beta) was about the same following oral (2.45 +/- 0.73 h; SD, n = 5) as after intravenous administration (2.25 +/- 0.35 h; SD, n = 6). The low oral bioavailability and rapid elimination of ketobemidone demonstrated in this study suggest that the usual dosage recommendation for oral Ketogin (ketobemidone 5--10 mg every 6--7 h) in patients with severe pain is too low.

Meningitis caused by Haemophilus influenzae in infant rats: protective immunity and antibody priming by gastrointestinal colonization with Escherichia coli

Infant rats aged five to seven days were fed Escherichia coli O75:K100:H5, E. coli O13:K92:H4, or saline and five weeks later were inoculated with Haemophilus influenzae type b. The incidence of bacteremia and meningitis was significantly less (P less than 0.05) for rats fed E. coli that possessed K100 capsular antigen (cross-reactive with type b capsular antigen) than for rats fed E. coli K92 or saline. Antibody to capsular antigen was not detectable in sera obtained from rats prior to challenge with H. influenzae type b, but five days after challenge, antibody levels were significantly higher (P less than 0.001) in rats colonized with E. coli K100 than in controls. These results, together with data from passive-immunization studies, suggested that the protection against infection with H. influenzae type b was due to priming or serum anticapsular antibody, although a protective role for cell-mediated immunity and/or secretory antibody could not be ruled out. E. coli K100 primed rats vaccinated with purified H. influenzae type b antigen for a significantly increased, although transient, anticapsular antibody response.

Antibody staining of 10-nm (100-A) filaments in cultured smooth, cardiac and skeletal muscle cells

Antibodies were prepared against the SDS-denatured 10-nm filament protein 'skeletin' extracted from chicken gizzard. The specificity of the antibody to the 10-nm filament protein was shown by immunodiffusion before and after purification of the protein on SDS gels by the enzyme-linked immunoabsorbent assay (ELISA) and by its specific absorption with purified skeletin. In immunofluorescence (where preimmune sera and antigen-absorbed antisera gave negative results), cultured cardiac, skeletal and smooth muscle cells and endothelial cells stained intensely. No staining was observed in fibroblasts present in these cultures, nor was there staining in glial cells or nerve cell bodies and fibres from sympathetic ganglion and Auerbach's plexus cultures. Smooth muscle cells (regardless of their source and phenotypic state) and endothelial cells stained intensely in the perinuclear region and in a fine filamentous network that existed throughout the cytoplasm. In both chick and rat skeletal and cardiac muscle (cultures and frozen sections) filamentous network staining was observed, while in rat muscle the antibody was additionally localized in a regular pattern in the region of the Z-disk, and in the case of cardiac muscle associated with the intercalated disk. The addition of 10(-6) M colchicine to the culture medium of smooth and striated muscle and endothelial cells resulted in an aggregation of the filaments in the nuclear region. Cultured smooth and striated muscle and endothelial cells and freshly isolated smooth muscle cells extracted of actomyosin and tubulin by high and low ionic strength solutions gave a staining pattern similar to non-extracted cells and in the electron microscope, exhibited filaments of predominantly 10 nm diameter.

Role of immunity in the clearance of bacteremia due to Haemophilus influenzae

The role of antibodies to capsular and somatic antigens in the clearance of Haemophilus influenzae was investigated by active and passive immunization. The clearance index (k) and the proportion of strain b organisms cleared 30 min after intravenous administration (deltaY30) were greater in eight-week-old actively immunized rats (k = 0.693, deltaY30 = 4.07) than in nonimmune animals (k = 0.075, deltaY30 = 0.95)(P less than 0.025 for all); however, clearance correlated imprecisely with titers of bactericidal or anticapsular antibody. In three-week-old rats, intranasal immunization with strain b or U significantly increased (P less than 0.005) the rate of clearance of strains b and U. Passive immunization with antibodies to somatic or capsular antigens significantly increased the rate of clearance (P less than 0.001) and the proportion of bacteria cleared (P less than 0.05) with all test strains. The increased clearance associated with passive immunization correlated with increased splenic uptake of 32P-labeled H. influenzae (r = 0.83, P less than 0.025). Analysis of the disappearance of viable organisms and bacterial 32P suggested that bacteriolysis of H. influenzae did not occur during clearance of the bacteremia. Either antibody to capsular antigen or antibody to somatic antigen, administered or evoked in rats, accelerates intravenous clearance of H. influenzae by promotion of reticuloendothelial phagocytosis.

Sexual behaviour and contraceptive practice of undergraduates at Oxford University

At the end of the 4th week of the Hilary Term 1977, 1006 male and 1009 female undergraduates at Oxford University were sent a questionnaire enquiring about their sexual behaviour and contraceptive practice. Of the 862 women and 634 men who replied, 512 women (59%) and 332 men (52%) had experienced sexual intercourse, 396 women and 191 men in the 4-week period preceding receipt of the questionnaire. No contraception had been used by 27% of the women on the first occasion that they had had intercourse; during the 4-week period preceding receipt of the questionnaire 10% of sexually active women had had intercourse on one or more occasions without using a contraceptive. The use of contraception increased with the frequency of intercourse and the stability of the relationship. Thirty-one women had been pregnant in the past; none was known to be pregnant at the time of the survey, although sixteen suspected that they might be. Ninety per cent of the students approved of the free distribution of a booklet on contraception and related matters to all undergraduates.

The neurotoxicity of misonidazole and its relationship to dose, half-life and concentration in the serum

Misonidazole has been given to a total of 87 patients. Neurotoxicity has occurred--convulsions with the higher doses and peripheral neuropathy with the lowern ones. The data from 34 patients receiving 4--7 doses has been analysed. Peripheral neuropathy is related to the total tissue exposure. By monitoring serum levels and controlling the total dose given, convulsions are avoidable and peripheral neuropathy restricted to a low and acceptable level.

Intrinsic tritium labeling of the capsular polysaccharide antigen of Haemophilus influenzae type B

The capsular polysaccharide of Haemophilus influenzae type b was intrinsically labeled with tritium by a microculture technique with 6-3H-D-glucose and was isolated in radioantigenically pure form by a combination of selective precipitation and molecular sieve chromatography. Labeling with tritated sugar residues approached one-fourth maximum and produced a specific activity 10-fold that previously described for extrinsic labeling methods. In radioantigen-binding assays for antibody, sensitivity depended on the size of the antigen; preparations were readily made that could detect 0.01 microgram Ab/ml in serum samples of 25 microliter. Stability of the labeled antigen appears limited only by the primary radiodecomposition of tritium.

Antibody of polyribophate of Haemophilus influenzae type b in infants and children: effect of immunization with polyribophosphate

Antibody to polyribophosphate, the capsular polysaccharide of Haemophilus influenzae type b, was measured in healthy ambulatory children by a radioactive antigen-binding assay. Titers fell from birth through nine months of age, then increased until six years, when they plateaued. Antibody activity was not correlated with the child's sex, ethnic status, or area of residence. Doses of 0.2-50 microgram of polyribophosphate given as single or booster doses had similar effects on antibody activity. Of 368 doses given to infants two to six months of age, 7% produced a significant antibody response; of 95 doses given to infants seven to 12 months old, 17% produced a response. The geometric mean titers of antibody resulting from immunization with polyribophosphate given at various times in relation to diphtheria-pertussistetanus vaccine did not differ significantly from one another or from titers observed in infants given only the latter vaccine. These data indicate that purified polyribophosphate will not provoke humoral immunity in young infants against H. influenzae type b and that it should no longer be considered as a candidate vaccine for this purpose.

Immunogenicity in weanling rabbits of a polyribophosphate complex from Haemophilus influenzae type b

Polyribophosphate (PRP), the capsular polysaccharide of Haemophilus influenzae type b, is more effectively immunogenic when it is associated with the bacterium than when it is in the purified form that is being tested as a vaccine for humans. In an effort to analyze this difference, we isolated from H. influenzae type b a high-molecular-weight, soluble complex, in which PRP appears to be combined with protein (about 7% protein). The pyrogenicity and limulus lysate gelation activity of the complex suggest that a small amount of lipopolysaccharide also is present. The protein was resolved into five polypeptides by electrophoresis in polyacrylamide gel containing sodium dodecyl sulfate. In weanling rabbits, which do not respond to purified PRP, the complex induces high titers of antibody of PRP, in an anamnestic pattern. Bactericidal antibody to other bacterial components was also elicited. Equilibrium density gradient centrifugation of the complex indicated that most of the immunogenicity of PRP resides in the least dense fractions, which are high in protein, low in polysaccharide, and active in the limulus lysate test; denser fractions that react strongly with limulus lysate but are poor in protein were much less immunogenic.

Isolation of the capsular polysaccharide from culture supernatant of Haemophilus influenzae type b

The capsular polysaccharide (CP) of Haemophilus influenzae type b is known to be spontaneously released from the cells in culture. The CP is precipitable from culture supernatant by the cationic detergent hexadecyltrimethylammonium. Most of the nucleic acid and some of the protein, but almost none of the endotoxin, in the supernatant are co-precipitated. Extraction of the precipitate with progressively stronger NaCl solutions separates nucleic acid and protein from the CP and also effects a molecular size fractionation. Residual endotoxin and protein can be reduced by extraction with cold phenol and ultracentrifugation. The resulting preparation has ribose, ribitol, and phosphate as principal components and contains less than 1% other sugars, protein, or nucleic acid; it elutes on Sepharose 2B as a symmetrical peak with Kav 0.51.

The role of encapsulation and host age in the clearance of Haemophilus influenzae bacteremia

Nonimmune rats given intravenous inoculations of 10(8) encapsulated Haemophilus influenzae type b cleared the bacteria at an exponential rate for 10 min; thereafter, the bacteremia plateaued at approximately 10(6) organisms/ml of blood. With 10(8) unencapsulated organisms, the initial clearance rate was significantly faster (P less than 0.001) and was complete by 30 min. The rate of clearance of a mutant strain of H. influenzae type b containing 0.1% as much capsular polysaccharide as the wild type was significantly faster (P less than 0.01), and H. influenzae type b from which a portion of the capsule had been removed physically had an intermediate clearance pattern. The addition of 1-1,000 mug of capsular polysaccharide to an inoculum of 10(8) organisms did not alter the clearance of the capsular polysaccharide-deficient mutant. The quantity of bacteria cleared during the 30 min after inoculation increased with the age of the animal. The initial bacterial clearance rate, corrected for animal and organ weight, also increased with age. These data are consistent with the proposal that physically integrated capsular polymer increases the virulence of H. influenzae type b by rendering it resistant to clearance from the bloodstream and that there may be an age-related increase in phagocytic activity that is reflected in increased clearance.

The paradox of Hemophilus infuenzae type B bacteremia in the presence of serum bactericidal activity

We investigated the role of serum bactericidal activity in Hemophiplus influenzae type b infections in infants with meningitis and in a rat model. In infected infants, 13/22 admission sera had bactericidal activity against the infecting strain, and bacteremia was as frequent in those with bactericidal activity (54%) as those without (56%). The coexistence of bactericidal activity and bacteremia was reproduced and studied in experimentally infected weanling rats. Serum from such rats kills in vitro 95% of conventionally broth-grown bacteria within 10 min, but does not kill organisms obtained from the infected animals. Thus bactericidal activity as conventionally determined for H. influenzae b may have no relevance in vivo, Incubation of broth-grown bacteria in normal rat serum for 30 min at 37 degrees C produces a resistance like that of in vivo organisms. This phenotypic conversion depends on factors that are of molecular weight less than 1,000, stable to 100 degrees C, but destroyed by ashing. When injected intravenously into nonimmune animals, broth-grown bacteria are quickly cleared, while serum-preincubated bacteria are not. The latter, however, are cleared when injected into bacteremic rats (half-life 30 min). Bacteremia in the rats may persist despite this capacity for clearance because bacteria are entering the blood from extravascular fluids, which contain greater than 90% of the total bacterial burden.

Synthesis and release of polyribophosphate by Haemophilus influenzae type b in vitro

Polyribophosphate, the capsular polysaccharide antigen of Haemophilus influenzae type b, can be assayed in crude bacterial extracts by a combination of immunoprecipitation, hot-acid extraction, and colorimetry. In vitro, the antigen is synthesized during growth and, in well-buffered media, in early stationary phase as well. It is shed from the cell throughout the course of synthesis, and at 37 C almost all the extractable antigen has been released spontaneously within several hours after synthesis. Various strains are similar in extent of synthesis and gross composition of the antigen; however, strains differ in the rate of release during exponential phase. The antigen is released as (or as part of) a very large structure, although under certain culture conditions much smaller antigenic units are found.

Circulating polyribophosphate in Hemophilus influenzae, type b meningitis. Correlation with clinical course and antibody response

In systemic infections caused by Hemophilus influenzae, type b, the capsular polysaccharide, polyribophosphate, is released into the circulation. Polyribophosphate was quantitated in serial serum and cerebrospinal fluid samples from 45 children with H. influenzae, type b meningitis by means of a radiolabeled antigen-binding inhibition assay. Polyribophosphate was regularly found in acute serum and cerebrospinal fluid samples and could be detected in unbound form for periods of 1-30 days after initiation of effective therapy. Complexes of polyribophosphate dissociable with acid and pepsin were detected in serum samples from 17 patients, in one case for a period of 145 days after hospitalization. Polyribophosphate levels and patterns of clearance were studied in relation to hospital course and antibody response. Patients with prolonged antigenemia had protracted fevers and severe neurological symptoms during hospitalization, frequently with focal complications.Antipolyribophosphate antibody responses were detected during the first 100 days of convalescence by radioimmunoassay in 79% of the patients studied, including 60% of the children 1 yr or less in age. The intensity of antibody response although clearly related to the age of the patient, was more reliably predicted by the efficiency of antigen clearance. Antibody responses were uniformly of low magnitude in patients with prolonged antigenemia, irrespective of age. Paients who failed to develop antibody to polyribophosphate after meningitis also exhibited impaired antigen clearance. These studies suggest that mechanisms necessary for clearance of polyribophosphate may influence the development and intensity of the humoral immune response and raise the possibility of developmental deficiencies in the clearance system in infants and children.

Two generators of hippocampal theta activity in rabbits

Spontaneous and hypothalamically induced theta activity was studied in rabbits lightly anaesthetized with urethane or urethane-chloralose. Well-developed theta activity was found over a large area of the dorsal part of the hippocampal formation, roughly corresponding to the CA1 field. Cross-correlation analysis between a stationary and a moving electrode showed that a large sheet of tissue oscillated in remarkable synchrony. This region was at least 8 mm along the longitudinal axis of the hippocampus and 6 mm in a plane transverse to this axis, thus comprising the whole of the rostro-caudal extension of the CA1 region. For technical reasons the temporal half was not explored. Depth recordings showed two foci of theta activity, one in the basal part of CA1 (stratum oriens) and a second, separate region with considerably larger amplitudes in the dentate region, having its maximum in the molecular layer. Due to the folded nature of the dentate fascia, an electrode often recorded two maxima corresponding to its upper and lower blades. Wave form analysis showed that the dentrate and CA1 rhythmic activity was roughly 180 degrees out of phase. The dentate theta activity remained in conditions where the CA1 theta activity was absent, either spontaneously or due to experimental interference. Systematic micro-electrode tracking showed absence of theta activity in the CA3 region. Nor was convincing theta activity found in the subiculum, parasubiculum, presubiculum or entohinal areas.

Selective localization of histamine to electron dense granules in antigen-challenged sensitized rat mast cells and to similar granules isolated from sonicated mast cells. An electron microscope autoradiographic study

The subcellular localization of histamine was studied in sensitized rat mast cells following antigen challenge and in granules obtained from sonicated cells, using an electron microscope autoradiographic technique. The mast cells were furnished with labelled histamine by incubation in 3-H-histidine. The silver grain distribution (reflecting the radioactive histamine) was highly non-random. The highest silver grain densities occured over homogeneous, electron dense (normal) granules and moderately electron dense granules. Swollen, less electron dense ("changed") granules with a reticular appearance and devoid of a limiting membrane had the lowest density of all subcellular structures studied and were therefore probably almost free of histamine. There was a good correlation between the percentage of electron dense granules, the histamine content and the silver grain density insaline-washed granule fractions isolated after sonication of mast cells for different times. These results support the hypothesis that histamine release occurs during the sequential exocytosis of storage granules, and during the sonication of mast cells, probably as a cation exchange between the amine, which is ionically bound to the heparin-protein complex of the granule matrix, and cations from the extracellular fluid. The exchanges will occur as soon as the perigranular membrane becomes premeable to water and cations.

Antibody responses to a combination vaccine against Haemophilus influenzae type b, diphtheria, pertussis, and tetanus

Forty-one children were studied in order to provide information on antibody responses to H. influenzae type b polyribophosphate (PRP), given in combination with diphtheria-pertussis-tetanus vaccine (DPT). When PRP was administered alone, 9 of 15 children demonstrated fourfold or greater increases in titres of anti-PRP antibody. In contrast, in the group receiving a combination vaccine consisting of DPT and PRP only 1 of 13 children showed a similar rise in anti-PRP antibody. It was concluded that, in the population studied, the combination vaccine was less effective than PRP alone. The reasons for this difference and its potential significance are discussed.

Immunization of humans with polyribophosphate, the capsular antigen of Hemophilus influenzae, type b

In human volunteers, single injections of purified polyribophosphate elicited antibodies detectable by passive hemagglutination and by serum bactericidal and opsonizing activities against viable Hemophilus influenzae, type b. All three activities rose by 2 wk to maximal levels, at which they remained for at least 6 months. Doses of 1 mug elicited antibody responses in nearly all recipients; higher doses of the antigen, however, produced larger increases in titer. Booster doses of 1 mug given at 6 months did not further increase the antibody titers. A tuberculin-like response was often observed at the site of injections given intradermally.

Human serum activities against Hemophilus influenzae, type b

Humoral immunity to Hemophilus influenzae, type b was studied in normal human adults by means of assays for serum bactericidal and opsonizing activities against the organism and for passive hemagglutinating activity using erythrocytes sensitized with polyribophosphate, the type-specific capsular antigen. Hemagglutinating activity was detectable in about 60% of the 114 sera tested. Serum bactericidal and opsonizing activities were found in all sera tested; the levels in some sera, however, were quite low. The antibacterial activities were due not only to antibodies directed against the polyribophosphate capsule but also to antibodies that appear to be directed against somatic antigens. Type b strains differed in their susceptibility to the antisomatic antibodies of particular sera but were uniformly sensitive to anticapsular antibody.

Electron microscope observations on compounds 48-80-induced degranulation in rat mast cells. Evidence for sequential exocytosis of storage granules

In vitro degranulation of rat mast cells was studied at different intervals ranging from 10 to 60 sec after adding the histamine liberator, compound 48/80 (0.4 microg/ml, 17 degrees C). The ultrastructural changes were followed by electron microscopy, and parallel assays were made to determine the histamine released. In addition, the extracellular tracers lanthanum and hemoglobin (demonstrated by its peroxidative activity) were applied to mast cells to follow communication of the extracellular space with the cavities formed during degranulation. After a lag period of 10 sec, degranulation started in the most peripherally located granules. The perigranular membrane fused with the plasma membrane, resulting in a pore bridged by a thin diaphragm. This was followed by rupture of the diaphragm and extrusion of the granule matrix (exocytosis). The process advanced towards the cell interior by fusion and opening of the deeper situated granules to the formerly opened granule cavities. At the end of the process, the cell was filled by a system of complicated cavities containing a number of altered granules. Extracellular tracers have shown that these intracellular cavities were in unbroken communication with the extracellular space from the very beginning of their formation. Both lanthanum and hemoglobin were found to be adsorbed to the limiting membrane of the cavities and bound to altered mast cell granules. In contrast, no tracer substance was present in nondegranulating mast cells. Degranulation of mast cells by compound 48/80 is regarded as a sequential exocytosis, a process similar to that described for some exocrine gland cells. All the "intracellular" cavities, formed by degranulation, were shown to communicate with the extracellular space; consequently, granules lying in these cavities must be considered as biologically extracellular. The present findings support the view that histamine is released from the granule matrix by the extracellular ionic milieu.

A clinical and electron microscopic study of a calcifying epithelial odontogenic tumour

The clinical features and the histological and ultrastructural appearances of a case of calcifying epithelial odontogenic tumour are described. The ultrastructural features of the cells of this tumour are comparable to cells of the stratum intermedium of the enamel organ. It is suggested that the amyloid-staining material found in this tumour is a cellular secretion rather than a cytoplasmic degeneration.