Primary lacrimal sac lymphoma with recurrence: a case report.

Primary lacrimal sac lymphoma is rare. The common clinical features are epiphora and medial canthal swelling which mimic nasolacrimal duct obstruction. Histological examination is therefore important to avoid delay in diagnosis and treatment. We report a case of primary lacrimal sac lymphoma in a 72-year-old female who developed a metachronous tumour at the hard palate one year after excision of the lacrimal sac tumour.

Shear modulus measurements on isolated human lens nuclei.

The use of a spinning lens test to determine ex vivo the shear modulus of 22 isolated human lens nuclei with ages ranging from 34 to 63 years is described. In this test procedure, the lens nucleus is spun about its polar axis. Images of the nucleus viewed from directions perpendicular to the polar axis are collected; these are used to quantify the deformations induced in the nucleus by the rotational motion. Data on these deformations are used to infer, by applying finite element inverse analysis, values for the shear modulus of the nucleus. The data on shear modulus obtained from this test program indicate that the nucleus stiffens very rapidly with age. These data are shown to compare well with the results of a related study (Wilde et al., 2012) in which the shear modulus of the nucleus is determined by similar spinning lens tests conducted on the entire lens substance.

Vibrant soundbridge: a new implantable alternative to conventional hearing AIDS in children.

The Vibrant Soundbridge is a new middle ear implantable hearing device. It was first introduced for adult patients with moderate to severe sensorineural hearing loss. With the innovation of the surgical techniques, its usage had been broadened for children and those patients with conductive and mixed hearing loss. We report first two cases of monoaural Vibrant Soundbridge implantation in Malaysia. They were children with bilateral conductive hearing loss who had failed to benefit from previous hearing aids. Floating mass transducers were attached in oval window and long process of incus respectively. Remarkable hearing yield was observed without surgical complication.

Simultaneous determination of dextrorphan and guaifenesin in human plasma by liquid chromatography with fluorescence detection.

A sensitive liquid chromatographic (LC) method was developed and validated for the simultaneous determination of dextrorphan and guaifenesin in human plasma using fluorescence detection. Dextrorphan and guaifenesin were extracted from plasma by a liquid-liquid extraction procedure using chloroform containing laudanosine as the internal standard. A cyano column (15 cm x 46 mm i.d., Spherisorb 5-CN) and a mobile phase containing acetonitrile-triethylamine-distilled water (10:1:89, v/v/v) (pH 6) were used. The concentration-response relationship for dextrorphan was found to be linear over a concentration range of 23-515 ng ml-1 with a lower limit of detection of 20 ng ml-1; the accuracy of the method would fall (95% confidence limit) within 9.53% and 11.07% of the true value for the inter-and intra-day, respectively; the inter- and intra-day precision, as measured by RSD, ranged from 1.88% to 30.07% (mean 2.28%) and from 4.69% to 7.51% (mean 5.67%) over the dynamic concentration range of the method (33-326 ng ml-1). The concentration-response relationship for guaifenesin was found to be linear over a concentration range of 181-8136 ng ml-1 with a lower detection limit of 30 ng ml-1; the accuracy of the method would fall (95% confidence limit) within 9.78% and 8.04% of the true value for the inter- and intra-day, respectively; the inter- and intra-day precision, as measured by the RSD, ranged from 2.55 to 6.07% (mean 3.90%) and from 3.12 to 3.90% (mean 3.52%) over the dynamic concentration range of the method (435-6430 ng ml-1).(ABSTRACT TRUNCATED AT 250 WORDS)

The inheritance of spontaneous amyloidosis development in mice: a model for hereditary threshold metabolic disorders.

To study the inheritance of spontaneous amyloidosis development in mice, we crossed the LLC strain (with a high incidence) with the A/J strain (with a low incidence) and with the HLC strain (with a zero incidence of amyloidosis). We produced the F1 and a backcross generation to each parental strain in each cross. Examination of the spleen, liver, and kidneys of each mouse for the presence of amyloid was made between age 15 and 18 months. The data fit neither a dominant nor a recessive single gene hypothesis for the development of amyloidosis. In consideration of amyloidosis as a hereditary threshold character, we developed an additive gene model. Subsequently, a test for fitness of the observed percentages to the expected percentages in the backcross generations was made according to this model. The observed percentages of amyloidosis in the spleens, livers, and individual mice agreed with the expected percentages in the LLC X A/J crosses but not in the LLC X HLC crosses. Therefore, we conclude that for the development of amyloidosis, a difference exists at one locus between LLC and A/J and at more than one locus between LLC and HLC. The probability of development of amyloidosis in an individual depends on the effects of the genes at these loci. For hereditary metabolic disorders that cannot be explained by either a single dominant or recessive gene hypothesis, this genetic model may be useful to test whether the development of the disease is due to additive effects of genes.

Amyloidosis development in LLC mice.

Using electron microscopy and the protein A-gold labelling technique we studied amyloidosis in the LLC mice, an inbred strain developing amyloidosis spontaneously. We found that the reticular cells lining around the sinuses in the red pulp of the spleen were converted to amyloid. Evidence suggests that the amyloid originates in the cells themselves. The process of amyloid formation is discussed.

Dactylaplasia in mice a two-locus model for development anomalies.

Dactylaplasia, characterized by the absence of phalangeal bones in the middle digits of each foot, resulted from a mutation that occurred in the SM7B/SM inbred strain of mice. Breeding tests revealed the mutant gene is an autosomal dominant that is homozygous lethal. Further investigation by outcrossing with a number of inbred strains showed that the manifestation of the mutant gene is controlled by another locus. At this locus are found two alleles: one, a dominant inhibiting dactylaplasia gene expression; the other, a recessive allowing the expression of the mutant gene. In each of the tested inbred strains, one or the other allele is present at this locus. We propose Dac as a symbol for the mutant gene, and mdac for the locus controlling the Dac expression. Mouse dactylaphasia closely resembles split hand/foot in man and in monkeys in gross morphology and mode of inheritance. The significance of the present findings explainable by a two-locus model is discussed relative to irregular mode of inheritance of certain other congenital defects, and also relative to the maintenance of genetic loads in populations.

Hemopoietic stem cell reconstitution from mouse strains differing greatly in leukocyte production.

Bone marrow cells or fetal liver cells from two strains of mice genetically different in leukocyte counts were injected into lethally irradiated F1 hybrids. The F1 mice which received bone marrow cells from the high leukocyte count (HLC) strain had sigificantly higher leukocyte counts than those which received marrow cells from the low leukocyte count (LLC) strain. Similar differences, although smaller, were found when fetal liver cells were injected. We tentatively conclude that the genetic characteristics of differentiation and proliferation of the hemopoietic stem cells are traits intrinsic to the cell, which remain essentially unaffected by the extracellular environment.

Spontaneous amyloidosis in LLC mice.

Practically all low leukocyte count (LLC) mice over 1 year of age develop renal amyloidosis. Renal amyloid is deposited in the glomeruli and in the interstitium between the convoluted as well as collecting tubules, with consequent development of cysts and necrosis. LLC mice die of chronic renal failure. Electron microscopic studies reveal amyloid fibrils in the mesangium, a thickening of the basement membranes, and fusion of the foot processes in the glomeruli. Massive amounts of amyloid fibrils are also present in the interstitium, where intracellular fibrils in the fibroblasts as well as in the tubular epithelium cells are found. Vesicles, which are probably formed from membrane disruption, and amorphous materials are seen along the basement membranes. LLC mouse amyloidosis is discussed with regard to its potential as a model for studies on amyloidosis as well as the etiology and origin of amyloid fibrils.

Reticular cell hyperplasia and amyloidosis in a line of mice with low leukocyte counts.

Two pathologic conditions, reticular cell hyperplasia and amyloidosis, were studied in a strain of mice selectively bred for low leukocyte counts (LLC). At the age of 3 to 6 months, 70% of the mice developed reticular cell hyperplasia in the inguinea lymph nodes, and at 11 to 18 months, about 100% of them developed amyloidosis in the spleen and in the kidney, liver, and adrenal glands. Immunofluorescence was revealed in the glomeruli, interstitium of the tubules, and the amyloid skeleton of the papilla when the kidney sections were incubated with fluorescein-labeled antimouse immunoglobulins. Both intracellular and extracellular amyloid fibrils were found in the liver, spleen, and kidney sections by electron microscopy. Distended rough endoplasmic reticulum (RER) cisternae and hypertrophy of RER with or without the simultaneous presence of amyloid fibrils in the reticular cells of the spleen and Kupffer cells of the liver were observed. In this light, we believe that the pathologic conditions are manifestations of immunologic events that are characteristic of the LLC mice with immune deficiency or abnormality in the immune system. We conclude that the origin of amyloid protein is at the RER. We discuss processes of amyloid fibril formation and some genetic aspects of amyloid development.

Genes associated with leukocyte production in mice.

We have investigated the genes influencing leukocyte production in mice by selective breeding for differences in leukocyte count and developed two major lines differing about 8-fold. In these lines we have made counter selective breeding, crossbreeding between them, and developed methods of using marker genes to search for individual genes distributed on different chromosomes. We have revealed an overall dominance of genes for low leukocyte count over those for high counts, and effects of genes at the agouti locus, certain mutant genes, and a gene or genes in the XVI linkage group. We have commented on the application and approach of quantitative genetic experimentation from both a theoretical and practical point of view and, on the basis of present results, discussed the nature of polygenes in relation to genes causing polymorphisms.

Class differences in the antibody response of HLC and LLC mice to sheep red blood cells.

The immune response to sheep red blood cells (SRBC) has been studied in two mouse lines selectively bred for a difference in leukocyte levels. Low leukocyte count (LLC) mice responded to multiple injections of 4 x 10(7) SRBC with a predominant IgM response whereas high leukocyte count (HLC) mice produced IgG almost exclusively, even after a single injection of SRBC. F1 mice responded like the LLC parent and backcross data implied genetic control at multiple loci. No correlation was found between the class of antibody produced in response to SRBC and the leukocyte count in backcross mice. Large numbers of plaque-forming cells (PFC) were detected in the spleens of HLC mice relative to the number detected in LLC spleens after primary and secondary immunizations with SRBC.