Fluorescein-conjugated lectin visualization of fungi and acanthamoebae in infectious keratitis

The authors investigated the efficacy of two fluorescein-conjugated lectins (FCLs), concanavalin A (F-ConA) and wheat germ agglutinin (F-WGA), to visualize microorganisms from clinical specimens with documented mycotic and acanthamoebic keratitis. Corneal scrapings from 18 patients with culture-proven keratomycosis and deparaffinized histopathologic specimens from five culture-proven cases of acanthamoebic keratitis were evaluated. The F-ConA provided consistently bright staining of the mycotic structures in each of the corneal scrapings. Both F-ConA and F-WGA stained acanthamoebic trophozoites and cysts in the histopathologic specimens. In both the corneal scrapings and the histopathologic specimens, the microorganisms were easily differentiated from background corneal cells and tissue. These staining patterns correlate well with the results from experimental studies, and with the known cell wall carbohydrate compositions for fungi and acanthamoebae. This study provides further evidence that FCLs (particularly F-ConA) may eventually become effective first-line stains for the visualization of microorganisms in specimens from ocular infections.

Multiple uterine leiomyoma with metastasis of an occult pulmonary carcinoma (a case report)

A rare case of metastatic leiomyoma of the uterine corpus presenting with haemoptysis is presented.

Stomal varices: percutaneous transhepatic embolization

Peristomal varices occasionally form in patients with chronic liver disease who have surgically created intestinal anastomoses and stomas. Hemorrhage from these varices carries an estimated mortality of 3%-4% per episode, as opposed to the 30%-40% mortality associated with gastroesophageal variceal bleeding. The cases of four patients who underwent transhepatic mesenteric vein catheterization with embolization of stomal varices for recurrent, intractable bleeding are presented. In three of the four patients there was no additional hemorrhage for at least 5 months. One patient was lost to follow-up. There were no complications. Since stomal variceal hemorrhage has a low mortality, transhepatic embolization is presented as a means of hemorrhage control when sclerotherapy fails and when shunt surgery presents an unacceptably high rate of morbidity and mortality relative to the underlying disease.

Antigen-presenting function of B lymphocytes

Here we review our current results studying B cells as APC and the mechanisms by which processed antigen is transported to and held on the cell surface for recognition by the specific T cell along with the MHC class II molecules. These studies were carried out using the globular protein cytochrome c as antigen for which the T-cell antigenic determinant was localized to a C-terminal 10-amino acid peptide fragment. For certain analyses, native cytochrome c or antigenic peptide fragments were covalently coupled to antibodies directed toward B-cell surface structures, allowing the targeting of antigen to the APC surface. Our findings indicate that all B cells function as APC and that the APC function is not differentially regulated in defined B-cell subpopulations. Using cytochrome c-antibody conjugates, it was shown that the surface Ig plays two significant roles in augmenting the B-cell APC function following antigen binding: signalling for enhanced APC function and concentrating antigen for subsequent internalization and processing. Both IgM and IgD appear to function identically in facilitating antigen processing in both immune and nonimmune B-cell populations. Furthermore, the surface Ig does not appear to be specially differentiated to function in concentrating antigen, as antigen artificially bound to other B-cell surface structures including MHC class I and class II molecules is also effectively presented. Lastly, evidence is presented that a previously described B-cell activating factor activity is strongly associated with the membranes of activated but not unactivated helper T cells, providing a mechanism by which the T-cell helper function can be focused on the specific antigen-presenting B cell. Concerning the mechanism by which processed antigen is presented at the B-cell surface, evidence is presented suggesting a role of peptide-binding chaperone proteins which may function to transport peptide to the APC surface and facilitate its association with the appropriate Ia. One candidate protein, PBP72/74, is described which binds peptides but not native antigens, is a member of the hsp70 family and appears to play a role in antigen presentation by the ability of antisera raised against it to block APC functions. Peptide-antibody conjugates were used to explore the spacial restrictions on MHC-restricted peptide presentation and it was shown that peptides covalently coupled to antibodies specific for Ig, class I or class II molecules are effective antigens in vitro even in the absence of processing.(ABSTRACT TRUNCATED AT 400 WORDS)

Ventilatory effects of naloxone via the sympathoadrenal system in the neonate?

Rabbit pups responded to hypoxia (6% O2 in N2) with a biphasic respiratory pattern, an initial increase by 1 min followed by a decrease. Naloxone (0.8 mg/kg) was found to abolish the declining phase of hypoxia, showing a sustained increase of ventilation throughout the hypoxic challenge. Phentolamine (30 micrograms/kg), an alpha-blocker, had no effect on the normal hypoxic response. However, pretreating the pups with phentolamine and then administering naloxone resulted in a biphasic response to hypoxia. We propose that the naloxone effects on ventilation are mediated in conjunction with the adrenergic system.

Respiratory cytopathology in chlorine gas toxicity: a study in 28 subjects

Bronchial brushings to evaluate cytopathologic changes were collected from 28 patients exposed to a toxic atmospheric level (66 parts/million) of chlorine gas. Postexposure smears collected on day 5 showed basal-cell and goblet-cell hyperplasia, acute inflammation, and chromatolysis of columnar epithelial cells. Columnar epithelial cell syncytia were observed in 15 (53.57%) smears. Nine (32.14%) smears showed abundant nonpigmented alveolar macrophages. Seven (25%) smears from mucosal erosions showed proliferating fibroblasts and capillary fragments; on day 15 and day 25 repeat smears from these seven cases showed evidence of epithelial regeneration and repair by fibrosis. This latter feature could lead to chronic ventilatory incapacitation in patients exposed to toxic levels of chlorine gas.

Relationship between lesion extent in 'Wernicke's area' on computed tomographic scan and predicting recovery of comprehension in Wernicke's aphasia

This study investigated the relationship between severity of auditory comprehension in Wernicke's aphasia and amount of temporal lobe damage within Wernicke's area (posterior two thirds of superior temporal gyrus region) as well as the total temporoparietal lesion size. There was a highly significant correlation between comprehension and the amount of temporal lobe lesion in Wernicke's area. There was no significant correlation between comprehension and the total temporoparietal lesion size. Patients with damage in only half or less than half of Wernicke's area had good comprehension at six months after the onset of stroke. Patients with damage in more than half of Wernicke's area had poor comprehension even one year after the onset of stroke. Additional anterior-inferior temporal lobe lesion extension into the middle temporal gyrus area was associated with particularly poor recovery.

Bees perceive illusory colours induced by movement

Certain black-and-white patterns, when rotated at appropriate speeds, can create the artificial perception of hues. We report that this illusion is not confined to human vision, but is also perceived by an insect, the honeybee. The findings suggest that certain features underlying the processing of colour information are shared by man and bee.

Persistently elevated AFP and AChE in amniotic fluid from a normal fetus following demise of its twin

Intrauterine fetal demise (IUFD) in one of twins at 12 weeks of gestation was accompanied by markedly elevated maternal serum alpha-fetoprotein (AFP) at 17 and 18 weeks. Amniotic fluid AFP from the healthy surviving twin's sac at 18.5 and 23 weeks was also greatly increased along with a positive acetylcholinesterase (AChE) band. Persistently elevated AFP and positive AChE so long after fetal demise--6.5 and 11 weeks post IUFD--has not, to our knowledge, been previously described. In similar cases, high level ultrasound and careful placental examination at birth should be utilized to search for fetal abnormalities or multiple pregnancy with IUFD.