Juvenile Tillaux fracture simulating syndesmosis separation: a case report

Determination of proliferative activity of non-Hodgkin's lymphomas (NHL), aimed at improving the prediction of their clinical behavior, has gained considerable attention in the recent years. Flow cytometry has allowed rapid measurement of the cellular DNA content in terms of ploidy and proliferative activity. Flow cytometric DNA analysis was performed on paraffin embedded biopsy specimens taken from 125 patients with NHL. In 90 of them, proliferative index (PI) could be accurately measured and correlated with histology grade of the Working Formulation (WF). Intermediate and high grade NHL (54 patients) were analyzed together as HG-NHL. With the discrimination point for PI of 10%, the survival of high and low proliferative lymphomas was compared in the whole NHL group and within the WF prognostic groups. The median PI was 5% in LG (low grade) NHL and 10% in HG (high grade) NHL group. Acturial survival in NHL with high proliferative activity (39 patients) was 31% at 5 years and 15% at 10 years, and in NHL with low proliferative activity (51 patients) 53% and 18%, respectively (p = 0.002). In HG-NHL, survival at 5 years for low proliferative cases was 55% and for high proliferative cases 28% (p = 0.065), whereas in the LG-NHL group it was 54% and 28%, respectively (p = 0.059). The survival at 10 years was nearly equal in all groups. Proliferative index was associated with the overall survival of NHL in the whole group, as well as within the LG and HG prognostic categories. PI could differentiate more and less aggressive NHLs both within LG-NHL and HG-NHL. A tendency of survival curves toward continuous relapse was observed in low proliferative NHL and a tendency toward "plateau" in high proliferative NHL, irrespective of the histology grade.     

Psychosexual development of women with congenital adrenal hyperplasia

Women with congenital adrenal hyperplasia (CAH) (N = 31) and their unaffected sisters or female cousins (N = 15) participated in a study of psychosexual development. All participants were > or = 18 years of age (mean age, 25 years; range, 18-40). Comparisons were also made between the CAH women with the salt-wasting (SW) form of the disorder and those with simple virilization (SV). A psychosexual assessment protocol examined six variables: (1) sex assignment at birth (probands only); (2) recalled sex-typed behavior during childhood; (3) gender identity and gender role identification in adulthood; (4) relationship status; (5) sexual orientation in fantasy; and (6) sexual orientation in behavior. Salt-wasting status and sex assignment at birth were also ascertained for the CAH women who either refused to participate in the study (N = 10) or could not be traced (N = 13). Compared to the controls, the women with CAH recalled more cross-gender role behavior and less comfort with their sense of "femininity" during childhood. The two groups did not differ in degree of gender dysphoria in adulthood, although the probands showed more cross-gender role identification. Three of the nonparticipant probands were living, as adults, in the male social role (2 reared from birth as boys and 1 who changed from the female to the male social role during adolescence). The CAH women and the controls did not differ in relationship status (married/cohabiting vs. single). The CAH women had lower rates of exclusive heterosexual fantasy and fewer sexual experiences with men than the controls; however, the CAH women did not have more sexual experiences with women than the controls. Comparisons between the SW and SV revealed several differences: the SW were less likely to be assigned to the female sex at birth, recalled more cross-gender role behavior during childhood, were less likely to be married or cohabiting, and had lower rates of sexual experiences with men. The results were discussed in relation to the effects of prenatal androgens on psychosexual differentiation.     

Crystal growth in dental enamel: the role of amelogenins and albumin

Amelogenin-mineral interactions were investigated using an in vitro binding approach. Rat incisor enamel matrix proteins (mainly amelogenins) were dissolved in synthetic enamel fluid and allowed to equilibrate with deproteinised developing enamel crystals. The results showed that amlogenin proteins of 21, 23, 24, 26 and 27-kDa (corresponding to nascent and partially degraded amelogenins) were associated with the crystals whilst the lower Mr amelogenins (< 21 KDa) remained free in the synthetic enamel fluid. These data suggest the nascent and partially degraded amelogenins may interact with developing enamel crystals and could influence their growth. Albumin-mineral interactions were investigated by extracting developing rat incisor enamel with synthetic enamel fluid. Insoluble material (including the enamel crystals) was then further extracted with 0.1 M phosphate buffer (pH 7.4) to desorb any mineral bound proteins. Western blotting using anti-albumin antibodies showed that almost all of the albumin from the secretory stage enamel and a significant proportion of the albumin present in early transition stage was extractable in the synthetic enamel fluid. However, synthetic enamel fluid did not extract albumin from late transition or maturation stage tissue, which could only be removed following further extraction with phosphate buffer. Albumin degradation was apparent during the transition and maturation stages, where it is degraded and ultimately removed. This binding pattern may be related to amelogenin degradation and removal during the transition stage, permitting albumin access to the previously obscured crystal surfaces. That the secretory stage matrix appears to "protect" secretory stage crystals from albumin may be an important consideration in the aetiology of enamel hypoplasias (i.e. incomplete crystal growth) and when using dissociative extraction procedures for the identification of mineral bound proteins.     

Technetium-99m labelling of the anti-tumour antibody PR1A3 by photoactivation

Irradiation of antibody with ultraviolet light leads to reduction of disulphide bonds. Thus irradiation can be used to generate free thiols prior to direct labelling of antibody with technetium-99m, and has a potential advantage over methods using chemical reducing agents such as mercaptoethanol or tin, in that no purification step is needed to remove excess reducing agent. We have used the photoactivation method developed by Sykes et al. to label the anti-tumour antibody PR1A3 with 99mTc. The antibody was irradiated at 300 nm using a Rayonet photochemical reactor with eight RMR3000 lamps. In a typical experiment, the antibody solution was injected into a nitrogen-filled borosilicate glass vial and purged with nitrogen. A degassed solution containing stannous fluoride and methylene diphosphonate was then added to the antibody and the vial was irradiated. Following the irradiation, [99mTc]pertechnetate was injected into the vial and the reaction mixture was incubated for 30 min at room temperature before being analysed by size-exclusion high-pressure liquid chromatography and instant thin-layer chromatography. Labelling yields greater than 95% were obtained using antibody concentrations ranging from 0.5mg/ml to 5mg/ml. Irradiation times as short as 5 min and tin to antibody ratios in the range between 11 and 32 microg tin per mg antibody gave high labelling yields. Labelling yields greater than 95% were obtained after storage of the photoactivated antibody at -70 degrees C for several weeks. The stability of the 99mTc-labelled photoactivated PR1A3 was similar to that of 99mTc-labelled mercaptoethanol-reduced PR1A3. The mean immunoreactive fraction was 77% for the photoactivation-labelled PR1A3, compared to 93% for PR1A3 labelled by mercaptoethanol reduction. Biodistribution studies were carried out using 99mTc-photoactivation-labelled PR1A3 or PR1A3 labelled by mercaptoethanol reduction in Balb/c mice and in nude mice with MKN-45 human tumour xenografts. There was no significant difference in tumour uptake between the mice that received photoactivated PR1A3 and those that received mercaptoethanol-reduced PR1A3. There was also no significant difference in uptake in most organs in Balb/c mice; however, the photoactivated antibody cleared more rapidly from the blood, and whole-body clearance was also faster for the photoactivated PR1A3. In conclusion, the photoactivation technique provides a very convenient "one-pot" method for labelling antibodies with 99mTc.     

Cloning of human cDNA encoding a novel heptahelix receptor expressed in Burkitt's lymphoma and widely distributed in brain and peripheral tissues

Using PCR with degenerate primers and screening of a human B-cell lymphoblast cDNA library, a full-length cDNA encoding a 375-amino-acid protein was isolated. It contains seven regions of hydrophobic amino acids probably representing membrane-spanning domains of a novel heptahelix receptor, tentatively named CMKRL2. It shows nearly 30% overall identity with the high-affinity IL8 receptor and similar degree of homology with other chemoattractant receptors, including the "fusin" coreceptors for HIV1. Measurements of various transduction pathways following application of a panel of chemokines to transfected cells failed to evoke any reproducible response. Although the natural ligand for CMKRL2 could, thus, not be identified, receptor expression in spleen and lymph nodes as well as in Burkitt's lymphoma (irrespective of EBV status) supports a functional role in activated B-cells. Receptor message was ubiquitously distributed in normal peripheral tissues and CNS, suggesting that CMKRL2 is expressed in widespread cell populations, such as macrophages and neuroglia.     

Identification of two distinct properties of class II major histocompatibility complex-associated peptides

We have examined the interactions of various peptides with the mouse class II major histocompatibility complex molecule I-Ak. The peptides were derived from the model protein hen egg white lysozyme (HEL). The immunodominant peptide of HEL is a 10-mer, residues 52-61. Our previous work established that this sequence contains the key residues for binding and presentation to T cells. Now we show that the binding of this 10-mer sequence resulted in complexes of I-Ak and peptide that, in SDS/PAGE (without boiling the protein), rapidly dissociated from the component alpha and beta chains. The binding interactions were studied in vitro, by incubating purified I-Ak and radiolabeled peptide, or ex vivo, by using antigen-presenting cells incubated with peptides. Peptides with additional residues at either the amino or carboxyl terminus behaved dramatically differently. Complexes of I-Ak with the longer peptides were stable to SDS/PAGE. Very few amino acid additions result in the change from unstable to stable complexes. The important issue here is that when cultured with HEL, antigen-presenting cells selected the HEL peptides containing the 52-61 sequences that favored stability [Nelson, C. A., Roof, R. W., McCourt, D. W. & Unanue, E. R. (1992) Proc. Natl., Acad. Sci. USA 89, 7380-7383]. Also, from other studies, such sequences correlate with a high immunogenicity of the peptide. We conclude that there are structural features of peptides that change the stability of the class II molecule and that are independent of the "core" peptide seen by the T cells.     

Pancreatic xanthomatous neuropathy associated with hyperlipidemia: a cause of abdominal pain mimicking chronic pancreatitis

"Hyperlipidemic crisis" is a term used to describe episodic abdominal pain in patients with hyperlipidemia. The morphologic correlates of this phenomenon have not been investigated and the etiology of the disorder is uncertain. We report a unique histologic finding in the pancreas of a 34-year-old woman with a 17-year history of episodic abdominal pain, sometimes accompanied by hyperamylasemia. At the age of 18 years, grossly elevated cholesterol and triglyceride levels were documented and type V hyperlipidemia was diagnosed. At the age of 34 years, subtotal pancreatectomy was performed for intractable abdominal pain. Histologic examination identified an increased number of enlarged pancreatic nerves that were infiltrated by foamy macrophages and encircled by fibrous tissue; endoneurial infiltration with macrophages occasionally split nerves into individual fascicles. Otherwise, the pancreas had only minimal fibrosis, nesidioblastosis, mucinous metaplasia of some pancreatic ducts, and scattered small collections of chronic inflammatory cells, subtle features suggesting very mild chronic pancreatitis. We propose that this novel xanthomatous neuropathy mimicked pancreatitis and was one of the underlying pathophysiologic mechanisms of abdominal pain in this patient. Further studies are necessary to document the prevalence of this new entity in patients with hyperlipidemia and to correlate its occurrence with "hyperlipidemic crisis" in those individuals.     

A rapid micromethod for measuring theophylline in serum by reverse-phase high-performance liquid chromatography

We describe an assay system for measuring theophylline in 25 microliters of serum. The procedure involves extraction with a 95:5 mixture of chloroform:isopropanol containing beta-hydroxypropyltheophylline as internal standard, and reverse-phase chromatography on a 4 mm x 30 cm column containing "micron Bondapak C18." Theophylline and beta-hydroxypropyltheophylline are eluted with a 90:10 mixture of sodium acetate butter (20 mmoles/litre pH 4.0) and acetonitrile at a flow rate of 1.8 ml/min., are detected by their absorbance at 254 nm, and quantitated by measuring peak areas. Column temperature has not been found to be critical in this analysis. Each analysis requires 9 minutes of chromatography time with a total analysis time of 20 minutes. Analytical recoveries were found to be 71 to 75% for theophylline and 94% for beta-hydroxypropyltheophylline. This difference in recovery is corrected when determining the theophylline concentration in unknown samples. The method has good precision (coefficients of variation between 7.0% and 7.9% for therapeutic and toxic concentrations). The results obtained with this method compare favourably with results obtained by a published cation-exchange high-performance liquid chromatographic method. None of the metabolites of theophylline, common compounds related to theophylline in structure or drugs tested have been found to interfere with the analysis described.     

Acute kidney failure in hypothermia

Two cases with acute renal failure after prolonged hypothermia are presented. Both patients were found in come, became rapidly uremic and required hemodilaysis treatment. Although the laboratory findings were typical of severe muscle damage, e.g. elevated levels of serum creatinine phosphokinase, serum lactic dehydrogenase and serum aldolase activities, visible "crush-injuries" were not found. Acute renal failure was characterized by extreme catabolism and severe metabolic acidosis. After 4 and 10 hemodialyses respectively, the patients became polyuric and finally were discharges with normal renal and muscle function. Hypotension with diminished renal perfusion and nontraumatic rhabdomyolysis due to prolonged hypothermia are regarded as the dominant pathogenetic factors in the acute renal failure.     

Subjective time experience in an intergenerational sample

The roles chronological age and gender play in subjective time experience were explored in a sample of 294 adult men and women. Subjective time experience (STE: the difference between subjective age and chronological age) was found to vary widely among individuals, with some being "accurate" (SA = CA), and others either "retarded" (SA less than CA) or "advanced" (SA greater than CA). Males were more retarded in STE than females at every point in the lifespan, and patterns of age differences in adulthood differed for the two sexes as well. The results suggest that chronological age may play a key role in transitions in STE, and that chronological age is more significant in the STE of women than in the STE of men.