The influence of pyridoxine in diabetic peripheral neuropathy

To determine the role of pyridoxine in the treatment of diabetic peripheral neuropathy, 18 symptomatic diabetic patients were treated with vitamin B6 or placebo in a double-blind controlled study. Only one patient had a low plasma pyridoxal phosphate level at the start of the study. After 4 mo of treatment with pyridoxine hydrochloride (50 mg three times daily) 6 of 9 pyridoxine-treated and 4 of 9 placebo-treated patients noted significant relief from their neuropathic symptoms. There was no difference between the two groups with regard to fasting plasma glucose, motor nerve conduction velocity, or ophthalmologic examination at the beginning or at the conclusion of the study. Our results suggest that vitamin B6 deficiency is not a factor in the etiology of diabetic peripheral neuropathy. Furthermore, treating diabetic peripheral neuropathy with high dose vitamin B6 or placebo results in a similar frequency of symptomatic improvement.

Toxic shock associated with tampon usage

A case of a 30-year-old woman who developed fever, diarrhoea and vomiting during the third and fourth days of menstruation, during which she was using tampons, is presented. The patient was admitted to hospital on the fifth day in shock , semicomatose, and with a generalized erythroderma. A presumptive diagnosis of toxic shock syndrome was made. Aggressive resuscitative and antibiotic therapy achieved a favourable outcome. An unused tampon from the same packet grew a Staphylococcus aureus of the same antibiogram and phage type as that isolated from the vaginal culture.

Serotypes among Neisseria meningitidis serogroups B and C strains isolated in Canada

Antisera made to prototype serogroup B strains of Neisseria meningitidis were used to serotype, by agar gel double diffusion, 262 meningococcal serogroups B and C strains isolated in Canada. The strains included 93 from patients and 169 from carriers. Serotype 2 was associated with 39 of 75 (52%) of group B strains and 14 of 18 (77.8%) of group C strains isolated from patients. The group B strains were mainly (87.2%) serotype 2b, while the majority (92.2%) of group C strains was serotype 2a. Other serotypes (including a new provisional serotype) represented 25.3 and 5.5% of groups B and C strains, respectively. The new serotype accounted for 13% of the group B strains. Approximately 23% of the strains isolated from patients were nontypable. The distribution of serotype 2, nontype 2 (other serotypes), and nontypable strains isolated from carriers was 2.1, 36.6, and 61.3%, respectively, for group B meningococci and 22.2, 29.6, and 48.25, respectively, for group C meningococci. Serotype 11 was the most prominent of the strains isolated from carriers. Approximately 7% of all the strains were multiple serotypes. Serotype 2 is an important virulence marker associated with meningococcal groups B and C disease in Canada, with serotypes 2a and 2b being markedly associated with groups C and B meningococcal disease, respectively.

Immune response of guinea pig tympanic membrane

The authors present the results of their experiment on the immune response of the guinea pig tympanic membrane. The first step was to develop an antiserum in the rabbit from the guinea pig tympanic membrane (RAGPTM). The lamina propria was used and IgG was identified as the main constituent of this antiserum. In their initial experiment, the RAGPTM IgG seemed to be specific to the acellular connective tissues of the respiratory tract and TM. The experiment presented here is concerned with the immune response of the guinea pig tympanic membrane. The animals were sensitized by intracardiac injection with the antiserum, and within one hour the right TM was traumatized in diverse fashions (bacteriological, chemical, mechanical traumas). The left TM served as a negative control. Animals were sacrificed at 24 hours, 7 days and 21 days. Immunofluorescence staining, complement studies (C23) and immunoperoxidase techniques were used on the TM. It appears that the GPTM can be antigenic in the rabbit. The right TMs of the sensitized guinea pigs reacted differently in the sense that there seems to be homing of the RAGPTM IgG to the site of trauma and that the complement participates in the reaction at least in the first week. The lamina propria of the TM is the site of the immune response. This work will need more elaborate studies but allows us to address different questions concerning the possible role of the combination of trauma and sensitization in conditions clinically involving the TM and middle ear.

Improved antiserum agar method for the serogroup differentiation of Neisseria meningitidis Y and W135

Rabbit antisera prepared to meningococcal serogroups Y and W135 strains were compared with horse antisera using the antiserum agar method (ASA) for the serogroup identification of Neisseria meningitidis. Thirty-seven group Y strains formed immunoprecipitates with the Y rabbit serum only, whereas the same Y strains formed immunoprecipitates with both the Y and W135 horse antisera. Forty-seven W135 strains formed specific immunoprecipitates with both the rabbit and horse W135 antisera by ASA. None of the 166 meningococcal isolates, representative of other meningococcal serogroups, formed immunoprecipitates with the groups Y and W135 rabbit or horse antisera. Use of specific Y and W135 rabbit antisera in ASA provides an improved technique for the serogroup differentiation of groups Y and W135 meningococci.

Antigenicity of the guinea pig's tympanic membrane

The immunogenicity of the middle ear constituents is a matter of prime importance. In this work, the authors were interested in the antigenicity of the guinea pig's tymphanic membrane. They reached the conclusion, after developing an antiserum (IgG), that the tympanic membrane of the guinea pig can be antigenic in the rabbit. After purification and absorption, a cross-reactivity remains between the tympanic membrane and the mucosae of the upper respiratory system.

Immunocompetence of the guinea pig's middle ear

Immunocompetence of the middle ear was studied in guinea pigs in two series of experiments. The first, afferent phase, consisted of grafting iso and allografts in the guinea pig's middle ear to sensitize the animals which were later to receive a skin graft on the back. The second, efferent phase, first sensitized the animals with a skin graft on their back and later in the middle ear. The results show a rather low capacity of the middle ear to elicit a second-set rejection of the skin grafts. This lack of sensitization is explained by the authors by the concept of tolerance.

Evaluation of the antiserum agar method for the serogroup identification of Neisseria meningitidis

The antiserum agar method (ASA), which is based on the formation of immunoprecipitates around bacterial growth on agar containing meningococcal hyperimmune horse serum, was evaluated for serogroup identification of Neisseria meningitidis. Four hundred meningococcal stains were serogrouped by ASA employing horse antisera to serogroups A, B, C, Y, W135, Z, and 29E and compared to serogroup identification by bacterial slide agglutination (BA) employing rabbit antisera. Overall, there was 95% agreement between the two methods. The ASA proved to be more accurate than BA since 15 strains which cross-reacted with Y and W135 rabbit antisera by BA were specifically serogrouped as either Y or W135 by ASA. In addition, 5 out of 75 strains which were ungroupable by BA were serogrouped as either B or 29E by ASA. Repeat serogroup identification of 100 meningococcal strains by ASA provided identical results thus showing the reproducibility of the method. The ASA is advantageous to BA since it is more reliable, utilizes standard antisera which do not have to be absorbed to remove cross-reactions, does not require the preparation of standardized bacterial antigen, and is simple to perform.

Mouse protective capabilities of Escherichia coli hybrids expressing Salmonella typhi antigens

An Escherichia coli hybrid, F1061, expressing Salmonella typhi somatic antigens 9 and 12, and a derivative of this hybrid, E. coli hybrid WR3078, expressing the S. typhi Vi antigen in addition to somatic antigens 9 and 12, were compared with S. typhi Ty2 in experiments to test their ability, as live vaccines, to protect Swiss white mice against death from challenge with a mouse-virulent Salmonella typhimurium hybrid expressing the S. typhi antigens 9, 12, Vi, and d. When the live, vaccinating organisms were administered intraperitoneally, 87.5% of the mice immunized with S. typhi Ty2 survived challenge, as compared with 62.5% of those immunized with E. coli hybrid F1061 and 55% of those inoculated with E. coli hybrid WR3078. When live organisms were administered orally at a dose of 10(9), 67.5% of the mice immunized with S. typhi Ty2 survived challenge as compared with 47.5% of those immunized with E. coli hybrid F1061 and 40% of those administered E. coli hybrid WR3078. Thus, the protection conferred by E. coli hybrid F1061 expressing only the S. typhi somatic antigens, although significant in this system, was inferior to that conferred by S. typhi Ty2 and the addition of the S. typhi Vi antigen to this hybrid (creating E. coli hybrid WR3078) did not enhance that protection.

Hyperoxic attenuation of exercise-induced bronchospasm in asthmatics

To investigate the mechanism of exercise-induced bronchospasm, we measured specific airway conductance before and after exercise in 7 healthy normals, 12 asthmatics with intact carotid bodies, and 5 asthmatics who had had bilateral carotid body resection. The subjects breathed either air or oxygen (randomly assigned) during cycle ergometer exercise. Post-exercise bronchodilation was the usual pattern in normals, whereas post-exercise bronchospasm occurred in all asthmatics who breathed air during exercise. Oxygen breathing during exercise markedly attenuated the post-exercise bronchospasm in those asthmatics with intact carotid bodies, but had no significant effect in those without effect in those without carotid bodies. The attenuation of the bronchospasm with oxygen occurred with either incremental or constant load exercise of high intensity. The degree of attenuation did not correlate significantly with changes in end-tidal PCO2, maximum work rate, maximum exercise ventilation, or maximum heart rate. These studies indicate that oxygen attenuates exercise-induced bronchospasm in asthmatics through its action on the carotid bodies.

Single unit responses in the inferior colliculus of the awake and performing rhesus monkey

1. The activity of single units in the inferior colliculus of unanesthetized monkeys was recorded during performance in an auditory reaction time task. Stimulus intensity and frequency were varied. 2. Spontaneous rate of unit discharge varied from 0 to 78.2 discharges per second, with a mean of 14.7 discharges/sec. 3. Both broadly and narrowly tuned units were encountered in the central nucleus of the inferior colliculus. The temporal discharge pattern of most units varied with changes in stimulus frequency; onset bursts and/or sustained discharge suppression dominated the unit discharge at the edges of receptive fields. 4. Half of the units examined at several intensity levels displayed nonmonotonic relationships between evoked discharge rate and stimulus intensity, with most nonmonotonic units showing a distinct "best intensity". The temporal response pattern of almost all units varied with changes in stimulus intensity, with onset bursts and discharge suppression increasing in occurrence with increasing intensity. 5. Units recorded in the external nucleus of the inferior colliculus displayed spontaneous rates which were similar to those of central nucleus units, and were affected by variation in stimulus intensity in the same fashion. However, the average initial latency of such units to intense stimuli was no longer than the latency of central nucleus units. 6. Variations in unit discharge with changes in stimulus frequency and intensity are consistent with an interaction of excitatory and inhibitory inputs with different initial latencies, dynamic ranges and receptive fields. In particular, our data suggest that inhibitory inputs have longer initial latencies and higher thresholds. Inhibition is stronger at the edges of a unit's receptive field, and dominates at high frequencies in units with low characteristic frequency. 7. Our data are not consistent with previous reports that single units in the unanesthetized animal display uniformly monotonic intensity functions and uniformly broad frequency responses.

Behavioral, compound action potential, and single unit thresholds: relationship in normal and abnormal ears

Comparisons were made for two species (chinchilla and mongolian gerbil) among mean behavioral audiogram, mean just detectable action potential (AP) responses to tone bursts, and single-fiber response thresholds at the characteristic frequency, averaged in one-octave bands. In normal animals and in a group of Kayamycin-treated chinchillas, these mean measures appear to have a well-ordered relationship. Unit and AP thresholds are within 10 dB from one another throughout the frequency range. Behavioral thresholds are usually 15--20 dB more sensitive, but the three curves are roughly parallel except at the highest frequencies, where the behavioral threshold begins to increase approximately one-half octave above the physiological ones. Individual examples for four gerbils and four chinchillas having hair cell losses due to Kanamycin intoxication reinforce the notion based on mean data that in most cases AP thresholds can serve to predict the behavioral threshold configuration.

The lipopolysaccharide (R type) as a common antigen of Neisseria gonorrhoeae. I. Immunizing properties

The ability of R-type lipopolysaccharide (LPS), isolated from Neisseria gonorrhoeae colony type 4, to protect against infection with N. gonorrhoea colony type 1 (T1 isolates) in the mouse and chicken embryo was investigated. C57 black mice were immunized intraperitoneally with 50 microgram of LPS, and challenged intracerebrally with 10-20 LD50's of N. gonorrhoeae colony type 1. Immunized mice were significantly protected (P less than 0.01 to less than 0.05) against challenge with different T1 isolates of N. gonorrhoeae when compared with non-immunized mice. Mice, injected with succinylated or alkali-treated LPS were not protected against gonococcal challenges. In a second animal model, leghorn hens were immunized intravenously with three injections of 500 microgram of LPS followed by a booster of 2.5 mg 2 weeks later. Embryonated eggs obtained from immunized hens were protected against challenge with 5 x 10(3) - 1 x 10(4) LD50's of three different T1 isolates. When hens were injected with the chemically modified LPS, the embryos were not resistant to gonococcal challenge. The results of this study demonstrate the ability of R-type gonococcal LPS to provide protection against different T1 isolates of N. gonorrhoeae.

The lipopolysaccharide (R type) as a common antigen of Neisseria gonorrhoeae. II. Use of hen antiserum to gonococcal lipopolysaccharide in a rapid slide test for the identification of N. gonorrhoeae from primary isolates and secondary cultures

An antiserum has been prepared in hens to R-type gonococcal lipopolysaccharide (LPS) and used in a simple slide-agglutination test for the identification of Neisseria gonorrhoeae. Anti-LPS serum agglutinated gonococcal cells representative of the four colony types of N. gonorrhoeae. Absorption of the antiserum with LPS removed the agglutinating activity. Secondary cultures (1120) were tested without observation of the colony type and all were agglutinated. No agglutination occurred with strains of Neisseria meningitidis, Neisseria lactamica, non-pathogenic Neisseria. Pseudomonas aeruginosa, Branhamella catarrhalis, or with species of lactobacilli and Acinetobacter. Cross-reactivity of the antiserum occurred with some streptococci. The anti-LPS serum was used to identify N. gonorrhoeae in primary isolates from the cervix, urethra, and pharynx. Of 251 gonococcal isolates tested, 249 were agglutinated by the antiserum, while all of the corresponding second cultures were agglutinated. The antiserum did not agglutinate N. meningitidis found in primary isolates from pharyngeal specimens. Anti-LPS hen serum should be useful for the rapid identification of N. gonorrhoeae in primary isolates or secondary cultures.

Homocytotropic antibodies (IgE) to Neisseria gonorrhoeae in the rat and a cross-reactivity of heterologous gonococcal strains

Outbred Wistar rats were immunised with a single intraperitoneal injection of a mixture of 30 mg of A1(OH)3 and 100microng of gonococcal zeolite antigen (ZA). Ten days after immunisation, ZA prepared from T1 and T4 colonies of Neisseria gonorrhoeae strain GC6 (GC6-T1 ZA and GC6-T4 ZA) were able to elicit a reaginic (IgE) response which declined to low levels by 35 days. There was a significant amount of histamine release from the mast cells of actively-sensitised rats on challenge with a specific gonococcal antigen. The antisera heated at a temperature of 56 degrees C for four hours failed to elicit a passive cutaneous anaphylaxis (PCA) reaction, indicating a lack of IgGa antibody. In addition antisera to GC6-T1 ZA gave a positive PCA reaction with GC6-T4 ZA and ZA prepared from T1 colonies of six heterologous gonococcal strains suggesting that these strains of N. gonorrhoeae share common antigenic determinants.

The effect of hyperimmunization with Neisseria gonorrhoeae on the presence of gonococcal antibody in serum, tissues, and secretions of the rabbit

Antibody responses in sera, tissues, and secretions of the urogenital tract and lower respiratory tract of rabbits hyperimmunized with Neisseria gonorrhoeae were examined. Antibody was detected by passive hemagglutination, whole-cell agglutination, bentonite flocculation, and in some cases immunodiffusion-in-gel. Immunization of rabbits either intravenously or intramuscularly resulted in the presence of gonococcal antibodies in the sera, spleens, and tissue of the urogenital tract (vagina, cervix, uterus, and fallopian tubes). Gonococcal antibody was also found in secretions bathing the mucosa of the urogenital tract and lower respiratory tract. Antibodies were not detected in sera, tissues, and secretions of non-immunized rabbits. The spleen was shown to synthesize gonococcal antibody in vitro in response to hyperimmunization. Tissues of the urogenital tract did not appear to synthesize gonococcal antibody thus suggesting and antibodies present in secretions of the urogenital tract were derived mainly from serum.

Effectiveness of parenteral and oral typhoid vaccination in mice challenged with a Salmonella typhi-Salmonella typhimurium hybrid

Live Salmonella typhi administered intraperitoneally, acetone-killed S. typhi administered intraperitoneally, and live S. typhi given orally, with their effectiveness decreasing in that order, protected Swiss white mice against death from challenge with a virulent Salmonella typhimurium hybrid expressing S. typhi antigens.

Development of hearing loss in kanamycin treated chinchillas

Behaviorally determined auditory thresholds of chinchillas were monitored before, during and after daily administration of kanamycin sulfate (200 mg/kg per day). Drug treatment was terminated as soon as a shift in high-frequency thresholds was observed. In surviving animals, hearing loss spread toward lower frequencies and stabilized after eight to nine days. The stable hearing loss was limited, on the average, to frequencies above 3 kHz. The magnitude of the loss was constant across frequencies and averaged about 40 dB. Virtually complete outer hair cell loss was seen in the basal portion of the cochleae of all surviving animals.

Preparation of gonococcal antigens by zeolite disruption

Neisseria gonorrhoeae cells are effectively disrupted with a synthetic zeolite, type 4A. The soluble material released from gonococci contains antigen(s) which are involved in the immune response to gonorrhea in experimentally infected chimpanzees and are common to different gonococcal strains.

Antibody production in milk serum of goats experimentally infected with Neisseria gonorrhoeae

Instillation of the goat's mammary gland with Neisseria gonorrhoeae colony type T1 has elicited and antibody response in the goat milk serum (GMS). Purification, and characterization of the GMS by gel filtration, electrophoresis, immunodiffusion, analytical ultracentrifugation, and serological analyses demonstrated thtat the active immune component was mainly in the IgA and IgG fractions (F2 and F3) of GMS.

The goat mammary gland as a model infection site for Neisseria gonorrhoeae

Live and formalin-killed gonococci were instilled into the mammary glands of lactating and nonlactating goats. In lactating goats viable gonococci elicited a limited inflammatory process whereas in non-lactating goats, severe inflammation and swelling appeared and peaked on the 3rd day after instillation and persisted for about 10 days. No viable gonococci were recovered after the first day, but fluorescent antibody staining showed gonococci in the exudate from non-lactating goats up to 7 days after instillation.