Immunogenicity in guinea pigs and tolerance in grass pollen-sensitive volunteers of enteric-coated grass pollen allergens

An acid-insoluble, methacrylic acid, methyl methacrylate copolymer (Eudragit L-100) was used to give an enteric coating to a grass pollen extract in order to protect it against gastric degradation. Substantial protection against the degradative effects of simulated gastric secretion was demonstrated using this preparation which was well tolerated by grass pollen-allergic volunteers. The enteric-coated allergen induced a greater secondary antibody response than did an aqueous presentation when administered orally to guinea pigs which had been primed previously by subcutaneous injection. This result indicates that an effective hyposensitisation regimen could consist of a short series of initial parenteral injections, followed by an oral course of the protected allergen.     

Serological analysis of the heat-stable antigens involved in serotyping Campylobacter jejuni and Campylobacter coli

Analysis with serotyping antisera showed that carbohydrate determinants were the dominant heat-stable antigens of Campylobacter jenuni/coli involved, whereas proteins did not contribute to the serological reactions. Lipopolysaccharide (LPS) along with a polysaccharide extract from whole bacteria (PS(WB] conferred strain serospecificity. In general, analysis with monoclonal antibodies in passive haemagglutination and co-agglutination tests showed the existence of similar antigenic determinants in LPS and PS(WB) of the same strain. However, in some strains determinants were detectable in LPS but not in PS(WB) using monoclonal antibodies, in other strains the situation was reversed. All of these monoclonal antibodies reacted with LPS in the more sensitive immunoblotting technique. The presence of 2-keto-3-deoxyoctonic acid in PS(WB) preparations, in the absence of endotoxin, supported the conclusion that PS(WB) was derived from LPS during extraction. The lack of detection of a reaction by monoclonal antibodies with LPS in passive haemagglutination, in contrast to immunoblotting, was suggested due to the presence of low concentrations of the relevant epitopes because of the procedure used to prepare the LPS tested.     

Phase Variation of Campylobacter jejuni 81-176 Lipooligosaccharide Affects Ganglioside Mimicry and Invasiveness In Vitro

The outer cores of the lipooligosaccharides (LOS) of many strains of Campylobacter jejuni mimic human gangliosides in structure. A population of cells of C. jejuni strain 81-176 produced a mixture of LOS cores which consisted primarily of structures mimicking GM(2) and GM(3) gangliosides, with minor amounts of structures mimicking GD(1b) and GD(2). Genetic analyses of genes involved in the biosynthesis of the outer core of C. jejuni 81-176 revealed the presence of a homopolymeric tract of G residues within a gene encoding CgtA, an N-acetylgalactosaminyltransferase. Variation in the number of G residues within cgtA affected the length of the open reading frame, and these changes in cgtA corresponded to a change in LOS structure from GM(2) to GM(3) ganglioside mimicry. Site-specific mutation of cgtA in 81-176 resulted in a major LOS core structure that lacked GalNAc and resembled GM(3) ganglioside. Compared to wild-type 81-176, the cgtA mutant showed a significant increase in invasion of INT407 cells. In comparison, a site-specific mutation of the neuC1 gene resulted in the loss of sialic acid in the LOS core and reduced resistance to normal human serum but had no affect on invasion of INT407 cells.     

Neuroendocrine carcinomas (carcinoid tumor) of the testis. A clinicopathologic and immunohistochemical study of ten cases

We studied 10 cases of primary pure testicular neuroendocrine carcinoma. Patients were between 16 and 48 years old and had testicular swelling with pain or a painless testicular mass and no history of neuroendocrine carcinoma or other malignant neoplasm. All underwent orchiectomy. The tumors were low (n = 9) and intermediate (n = 1) grades with a variegated histologic appearance characterized by a nesting pattern, cords of neoplastic cells with rosettes, or sheets of neoplastic cells. Mitotic activity was lacking in 9 cases. In 1 case, mitotic figures ranged from 7 to 8 per 10 high-power fields, and cellular atypia and comedo-like necrosis were present. Immunohistochemical studies using a keratin cocktail, chromogranin, synaptophysin, epidermal growth factor, p53, placental-like alkaline phosphatase, and CD117 (c-kit) were performed in all cases. Keratin, chromogranin, and synaptophysin were positive in all tumors. Clinical follow-up information was obtained for 6 patients (range, 12-60 months): 5 with low-grade tumors were alive 24 to 60 months after diagnosis; 1 with an intermediate-grade tumor died of tumor 12 months after initial diagnosis. The behavior of these tumors, while in the testicular region, correlates well with the histologic grade. We propose replacing the term testicular carcinoid with neuroendocrine carcinoma, which better reflects the nature of these neoplasms.     

Effect of eye rotation on visual-field map onto superior colliculus and visual cortex

We used multiunit recording to assess the effect of rotating one eye approximately 90 degrees at about the time of normal eye opening. Rotation of the eye did not alter the topography of the retinal maps onto visual cortex or superior colliculus. The intorted eye drove cells at most recording points in the contralateral visual cortex and superior colliculus. In its ipsilateral colliculus the intorted eye drove cells at about 10% of the recording points; that is, the temporal retina of this eye was quite ineffective in driving collicular cells. In its ipsilateral cortex the intorted eye drove cells at about 30% of the recording sites. The unoperated eye drove cells at all locations in both colliculus and cortex on both sides of the brain. The effects of extorsion were studied only in the superior colliculus. Extorsion and intorsion produced similar results except that extorsion produced a less severe deficit in the ability of the temporal retina to drive cells in its ipsilateral colliculus. Cutting all the extraocular muscles without eye rotation was studied only in the colliculus and produced results similar to those produced by intorsion and extorsion. However, the temporal retina of the operated eye was more effective after muscle cut alone than after intorsion or extorsion. Forcing the animal to use the rotated right eye alone on alternate days during the first 3 mo of life did not decrease the deficits. Almost all recording sites in the right colliculus were driven only by the unoperated left eye. If the left eye was sutured when the right eye was rotated, only the right eye drove cells in the left colliculus, but the two eyes were about equally effective in the right colliculus; however, rather few sites in the right colliculus were binocularly driven. We conclude that both extraocular muscle section and eye rotation reduce the effectiveness of the uncrossed input from the operated eye to the superior colliculus and visual cortex. The effects on the superior colliculus are, however, greater.     

Bilateral simultaneous tubal sextuplets: pregnancy after in-vitro fertilization--embryo transfer following salpingectomy

The presence of a damaged tube has been suggested in recent studies to have a negative effect on in-vitro fertilization (IVF) outcome. Performing bilateral salpingectomy prior to IVF to maximize pregnancy rates may also result in unnecessary surgery. This case is also an example of the occurrence of interstitial pregnancy after salpingectomy. This unusual type of ectopic pregnancy must be kept in mind when evaluating a patient suspected of a possible early abnormal gestation after assisted reproductive technolologies.      

Pulmonary artery angiosarcoma: a clinicopathologic and radiological correlation

A 69-year-old man presented with cough, shortness of breath, and fatigue. He was initially treated for allergies and then for pulmonary embolism. Radiologically, a tumor mass was found to occlude the right pulmonary artery and involve the pulmonary trunk. A right pneumonectomy was performed. Histologically, a cellular malignant spindle and epithelioid tumor with areas of necrosis and brisk mitotic activity was seen. In some areas, the tumor appeared to form vascular channels. Focal osteosarcomatous differentiation was present. Immunohistochemical studies were performed including vimentin, smooth muscle actin, desmin, CD31, CD34, S100, and pan-cytokeratin. The tumor cells were positive for CD31 and vimentin and negative for pan-cytokeratin, CD34, and S100. Two months after surgery, the patient was alive and well.     

An in vitro study of a microbubble contrast agent using a clinical ultrasound imaging system

Optimal insonation settings for contrast imaging are yet to be specified, mainly due to the lack of good understanding of the behaviour of the microbubbles. A satisfactory model that explains the behaviour of individual contrast agent scatterers has not yet been reported in the literature. An in vitro system based on a commercial scanner (ATL HDI3000) has been developed to investigate the backscatter of such agents. Suspensions of Definity were introduced in an anechoic tank. The frequency of transmitted ultrasound varied from 1 to 5 MHz, pulse period from 2 to 10 periods and peak negative acoustic pressure from 0.08 to 1.7 MPa. The backscatter at the fundamental and second harmonic frequency windows from the agent was normalized in terms of the corresponding components of backscatter from a blood mimicking fluid suspension. The agent provided a dominant resonance effect at 1.6 MHz transmit frequency. Second harmonic normalized backscatter averaged around 9 dB higher than the fundamental. The normalized fundamental backscatter intensity was linear with peak negative pressure. The second harmonic at resonance peaked at 0.5 MPa suggestive of bubble disruption above such pressure. The system proved capable of illustrating the ultrasonic behaviour of Definity in vitro, and the investigation suggested particular insonation conditions for optimal image enhancement using Definity.     

Lymphocyte transformation responses to phytohaemagglutinin and pokeweed mitogen in patients at differing stages of HIV infection: are they worth measuring?

AIMS--To determine whether the routine measurement of lymphocyte transformation responses to mitogenic stimuli provide any information additional to that available from routine T cell CD4 and CD8 analysis in patients with HIV infection. METHODS--The case records of 197 immunologically investigated HIV seropositive patients were reviewed. The influence of disease stage on T lymphocyte subsets and lymphocyte transformation responses (LyTR) to phytohaemagglutinin (PHA) and Pokeweed mitogen was assessed. RESULTS--The median CD3 and CD4 counts and LyTR to PHA and Pokeweed mitogen were highest in patients with persistent generalised lymphadenopathy (PGL) and decreased progressively in the order: asymptomatic patients, those with ARC, those with AIDS. LyTR to PHA was preserved in over 70% of all patients, but the response to Pokeweed mitogen was depressed in 8% of patients with PGL, 34% of asymptomatic patients, 68% of those with ARC and 78% of those with AIDS. Subnormal values of both CD4 + T cells and LyTR to Pokeweed mitogen were more common in patients with ARC and AIDS (68%) than in those who were asymptomatic or had PGL (20%). CONCLUSIONS--CD4 T cell analysis and LyTR to Pokeweed mitogen, but not to PHA, both correlate with disease states in patients with HIV infection.