On the role of the second-order derivative term in the calculation of convergent beam diffraction patterns.

The simulation of (scanning) transmission electron microscopy images and diffraction patterns is most often performed using the forward-scattering approximation where the second-order derivative term in z is assumed to be small with respect to the first-order derivative term in the modified Schrödinger equation. This assumption is very good at high incident electron energies, but breaks down at low energies. In order to study the differences between first- and second-order methods, convergent beam electron diffraction patterns were simulated for silicon at the [111] zone-axis orientation at 20 keV and compared using electron intensity difference maps and integrated intensity profiles. The geometrical differences in the calculated diffraction patterns could be explained by an Ewald surface analysis. Furthermore, it was found that solutions based on the second-order derivative equation contained small amplitude oscillations that need to be resolved in order to ensure numerical integration stability. This required the use of very small integration steps resulting in significantly increased computation time compared to the first-order differential equation solution. Lastly, the efficiency of the numerical integration technique is discussed.

Alagille syndrome: case report with bilateral radio-ulnar synostosis and a literature review.

We report a case of Alagille syndrome (arteriohepatic dysplasia) with the unusual radiological abnormality of synostosis of the proximal portions of the radius and ulna bilaterally, a manifestation which, to our knowledge, has not previously been described in a specific patient in the English language literature. We also describe additional features of the syndrome in the same patient and review the published literature on radiological manifestations of this condition.

Respiratory symptoms as an indicator of undiagnosed bowel perforation following laparoscopic surgery--an observation.

Undiagnosed bowel perforation following diagnostic or operative laparoscopies is associated with significant morbidity and is indeed the primary cause of laparoscopy related mortality. The diagnosis of bowel perforation remains difficult, predominantly because of the highly varied clinical presentation. Respiratory symptoms have rarely been reported. We outline eight cases of undiagnosed bowel perforation in which the respiratory symptoms of dyspnoea and tachypnoea manifested themselves as an integral part of the clinical presentation. We believe these 'atypical' symptoms potentially further delayed the diagnosis and instigation of definitive management. Dyspnoea and other respiratory symptoms should be considered as additional warning signs of possible undiagnosed bowel perforation following laparoscopic surgery

Operative photography in gynaecological endosurgery.

OBJECTIVES: To define the attitude of patients, doctors and nurses to operative photographs captured at gynaecological endosurgery, and to determine the value of these photographs in patient education. DESIGN AND SETTING: Postal questionnaire survey of specialists, general practitioners, nurses and patients at a tertiary referral hospital in south-west Sydney. PARTICIPANTS: All patients who underwent endoscopic gynaecological surgery between 1 February and 1 May 1998, and for whom good quality operative photographs were available, and medical and nursing staff randomly selected from lists of practitioners within the Southwest Sydney Area Health Service. MAIN OUTCOME MEASURES: Opinions on whether operative photodocumentation assists patients in understanding their condition; the value to patients of these records; whether operative photographs assist referring doctors in subsequent management of patients; the use of operative photographs in medical records or as personal records for patients; whether photographs may lead to anxiety or be used in medicolegal action. RESULTS: All patients believed operative images were valuable in helping them understand their condition. 19 of 20 specialists (95%), 85 of 123 general practitioners (69%) and 23 of 28 nursing staff (82%) also believed that operative images assist patients in understanding their disease. Nearly all patients denied that operative images would create anxiety, and specialists, general practitioners and nurses also felt that the photographs would not cause anxiety. 78% of general practitioners expressed a desire to receive operative images. CONCLUSIONS: Photographic records of operative procedures are regarded as valuable by both referring doctors and their patients. Patients find photographs useful in understanding their disease.

Intestinal parasites of the chimpanzee Pan troglodytes in Kibale Forest, Uganda.

One-hundred-and-twenty-three stool samples were examined from 45 chimpanzees in a natural population in western Uganda. Comparison with previous studies is complicated by the diversity of techniques used and interpretations. The Ugandan population had relatively many intestinal protozoa, including the probably beneficial entodiniomorph ciliates. Strongyloid nematodes are universal among chimpanzees, but were surprisingly absent from those on Mount Assirik in Senegal. Railletina tapeworms are sporadic in their occurrence. The absence of spiruroid nematodes in the Ugandan population reflects the absence of insectivory in this population. There was little evidence of seasonal difference in prevalences.

Implications for port placement of deep circumflex iliac artery damage at laparoscopy.

A cannula injury to the deep circumflex iliac vessels led to substantial morbidity and required surgical repair. Surgeons must increase their awareness of the anatomy of these vessels and place laparoscopic ports to minimize the risk of injury. (J Am Assoc Gynecol Laparosc 6(2):221-223, 1999)

Protection against Schistosoma mansoni and associated immune responses induced in the vervet monkey Cercopithecus aethiops by the irradiated cercaria vaccine.

The efficacy of the radiation-attenuated schistosome vaccine in eliciting protective immunity was investigated in the vervet Cercopithecus aethiops. Three groups of test animals received one, three, or five exposures to 5,000-9,000 cercariae attenuated with 30 krad of gamma radiation from a 137Cs source, while a fourth group served as challenge controls. After a single vaccination, no statistically significant protection was found; after three vaccinations it reached its highest peak (48%) and five exposures resulted in reduced protection (39%). Examination of immunologic parameters supported these findings, with proliferative responses of peripheral blood lymphocytes being greatest in the group vaccinated three times. Specific immunoglobulin G (IgG) levels also peaked after three vaccinations, with clear evidence of a reduction after the fourth and fifth exposures. There was a clear correlation (r = 0.66) between the antibody level at the time of challenge and the protection observed in individual vervets. These data demonstrate that protective immunity to Schistosoma mansoni can be achieved with the attenuated vaccine in a highly susceptible nonhuman primate (i.e., 82% maturation of penetrant cercariae was recorded in challenge control animals in this study). However, they also indicate that there is a ceiling to this protection. Furthermore, increasing the number of vaccinations beyond a certain point, instead of boosting protection may cause it to diminish, possibly due to the induction of immunoregulatory mechanisms.

Protective immunity to Schistosoma mansoni induced in the olive baboon Papio anubis by the irradiated cercaria vaccine.

The radiation-attenuated schistosome vaccine induces a high level of protective immunity in rodents. In order to assess its potential relevance to man, we have tested its efficacy in the non-human primate Papio anubis. A vaccination regime consisting of 3 exposures of approximately 9000 cercariae irradiated with 30 or 60 krad. of gamma radiation induced > 50% protection to a challenge with normal larvae. A lower attenuating dose of 20 krad., optimal for vaccination of mice, was less effective. All vaccination regimes elicited a population of PBMC which proliferated in vitro in response to antigen. These responses peaked after the third exposure but were significantly lower after challenge. They revealed relatively little cross-reactivity with adult Schistosoma haematobium antigens and provided some evidence for stage-specific antigens. Circulating IgM reactive with adult S. mansoni antigen was detected after the second vaccination but levels remained low throughout. In contrast, IgG levels were boosted by successive vaccinations, although they showed a tendency to decline from 14 days after each exposure. There also appeared to be a lag of about 14 days after challenge before levels began to rise. Thus, both proliferation and antibody data suggest a lower responsiveness after challenge which may reflect either the reduced antigenic load or immunogenicity of normal, compared to vaccinating larvae. The data indicate that the attenuated schistosome vaccine is capable of inducing protection in a highly permissive primate host, with the implication that the mechanisms involved may also be relevant to man.

Soft tissue tuberculosis: a series of 11 cases.

OBJECTIVE: To describe the clinical characteristics of soft tissue tuberculosis (TB). METHODS: Retrospective review of all cases of soft tissue TB seen by the authors. RESULTS: Eleven cases were seen between 1988 and 1994. All patients but one were foreign born. Six patients had collagen vascular disorders and another had a kidney transplant. Five were taking immunosuppressive therapy and/or prednisone. Three had preceding trauma to the affected area. Five had evidence of previous TB by history or chest radiograph. Symptoms (mean duration 4.4 months) included swelling and pain and often mimicked the underlying disease. Six patients had definite or suspected active TB at other sites. Good initial responses were seen with debridement or drainage and multiple drugs for 6 to 12 months. Two patients have had possible relapses at other sites. Medication intolerance was frequent. CONCLUSION: TB should be considered in patients who present with unexplained soft tissue swelling and pain, particularly if they are immunosuppressed, were foreign born in an endemic area, have an abnormal chest radiograph, or have had trauma to the affected area.

Schistosoma haematobium in the baboon (Papio anubis): assessment of protection levels against either a single mass challenge or repeated trickle challenges after vaccination with irradiated schistosomula.

Baboons vaccinated intramuscularly with three times 9000 20 krad irradiated Schistosoma haematobium schistosomula at monthly intervals were exposed percutaneously to either a single mass challenge of 3000 (VMC) or ten, weekly trickle challenges of 300 (VTC) normals S. haematobium cercariae. Unvaccinated mass (MCC) or trickle (TCC) challenge controls were exposed simultaneously. Faecal and urine egg production was delayed in the vaccinated groups which also had reduced adult, particularly female, worm recoveries. Total faecal, urine and tissue eggs were lower in the vaccinated groups, as also were the size of granulomata and the gross pathology and severity of inflammatory responses in the bladder and ureters, except for an increased proportion of tissue eggs in the livers of vaccinated animals. Differences in pathology between groups were less marked in the other organs. Most indices were reduced in the trickle versus the mass challenge control groups. Some of these trends were statistically significant, mostly in the trickle vaccination group (VTC), but others were not. Compared with the appropriate unvaccinated controls, the percentage reduction for the trickle challenge (VTC) group (73%) was three times greater than that of the mass challenge (VMC) group (23%). Overall, the protective effect of vaccination was more clearly demonstrated in the trickle than in the mass challenge groups. This conclusion is based on a single experiment. Nevertheless, because trickle infections probably approximate more closely to what humans receive naturally, it is recommended that they should be used for future testing of all potential vaccines in baboons.

Structure and function of the cibarial armature in Simuliidae.

Cibarial armature morphology in adult female blackflies (Diptera: Simuliidae) is described using scanning electron microscopy. Three distinct types of armature are recognized, comprising those with teeth, e.g. Simulium ochraceum, S. ornatum, S. veracruzanum and S. vorax, those with spicules, e.g. Austrosimulium bancrofti, S. damnosum, S. exiguum, S. metallicum and S. neavei; and those lacking these projections, e.g. Prosimulium rufipes and S. lineatum. Whereas the armature is poorly developed in vectors of human onchocerciasis such as S. damnosum, S. exiguum, S. metallicum and S. neavei, the well-developed armature in S. ochraceum, S. veracruzanum and S. vorax does not prevent these species becoming infected with Onchocerca spp. (Nematoda: Onchocercidae). Hence the armature is not primarily a mechanism to counteract microfilaria superinfection. Since cibarial armatures are more developed in the haematophagous females than in the males of certain Families of flies, e.g. Ceratopogonidae, Culicidae, Phlebotominae and Simuliidae in the sub-order Nematocera, evidently the armature has evolved in response to the blood-feeding habit. As the suction of imbibed blood by the cibarial pump may require a valve mechanism to prevent back-flow, it is suggested that the armature is primarily for this purpose. Secondarily, the cibarial armature presents a damaging barrier against ingested microfilariae.

Regenerative amplification of 30-fs pulses in Ti:sapphire at 5 kHz.

18-fs pulses from a self-mode-locked Ti:sapphire laser are amplified to 60 microJ of energy at 4.9 kHz with chirped-pulse amplification in a Ti:sapphire regenerative amplifier. After recompression, 30-35-fs, near-transform-limited pulses are obtained.

Protective immunity in baboons vaccinated with a recombinant antigen or radiation-attenuated cercariae of Schistosoma mansoni is antibody-dependent.

Mice vaccinated with radiation-attenuated cercariae of Schistosoma mansoni exhibit high levels of resistance to challenge infection. We have previously shown that sera from these mice recognize polypeptides that are expressed on the surface of newly transformed schistosomula. We have cloned and sequenced a cDNA that encodes a 62-kDa portion of one of these polypeptides. Vaccination of mice with this 62-kDa polypeptide (designated rlrV-5) elicits high antibody titers and significant resistance to challenge infection. We report here the results of a vaccination trial in baboons with the rlrV-5 or radiation-attenuated cercariae. rlrV-5 was presented either in the form of protein micelles or complexed with the outer membrane protein of meningococcus to form proteosomes. The level of protection achieved in these groups ranged from 0 to 54%, with a mean of 27.7%. In baboons exposed to radiation-attenuated cercariae the level of protection was very high, with a mean of 84%. The resistance observed after vaccination with rlrV-5 or radiation-attenuated cercariae was reflected in the overall histopathology. Vaccination of baboons with rlrV-5 or radiation-attenuated cercariae elicited an antibody response against epitopes exposed on the surface of newly transformed schistosomula. In the case of baboons vaccinated with radiation-attenuated cercariae, this response was not limited to epitopes encompassed by rlrV-5. Analysis of individual baboon sera by ELISA demonstrated that there was a direct correlation between the anti-rlrV-5 titer and resistance to challenge worm burden, suggesting that the immunoprotective mechanism is antibody-dependent.

The potential of vervet monkeys (Cercopithecus aethiops) and baboons (Papio anubis) as models for the study of the immunology of Echinococcus granulosus infections.

Nine vervet monkeys and nine baboons were infected with eggs of Echinococcus granulosus per os. Six of the vervets and one of the baboons possessed hydatid cysts at autopsy, 15-28 months post-infection. The sequential IgG response to hydatid fluid and protoscolex antigens showed considerable inter-animal variation. Infected vervets and baboons became seropositive after an average of 8 months post-infection. Considerable fluctuation in the IgG response was observed, particularly to the hydatid fluid antigen which, in humans, may contribute to the existence of a significant proportion of seronegative individuals. Vervets, in particular, may be useful to study immunological events associated with exposure, development and resolution of hydatid disease in outbred human populations.

Unusual rheumatological and cardiological manifestations of acute myelogenous leukemia in a patient with Klinefelter's syndrome.

We report the case of a 40-year-old man with Klinefelter's syndrome who presented with a complex multisystem illness, the predominant manifestations of which were rheumatological and cardiological. This disorder coincided with a diagnosis of acute myelogenous leukemia evolving out of a myelodysplastic syndrome and resolved completely after chemotherapy. It is concluded that the hematological malignancy probably played a causal role in the development of this unusual illness which was likely immunologically mediated.