Radiocontrast medium induces histamine release in association with upregulation of miR‑19a‑3p and miR‑362‑3p expression

In Taiwan, the use of radiocontrast medium for clinical image diagnosis recently surpassed one million times and the overall prevalence of radiocontrast hypersensitivity was ~7%. A microRNA (miRNA/miRs) is a small non-coding RNA molecule that mostly plays a suppressor role in cells. However, the roles of miRNA expression in radiocontrast-induced mast cells activation remains to be elucidated. The aim of the present study was to investigate the role of miRNA on radiocontrast-induced mast cell activation. Computed tomography radiocontrast, ultravist and mouse mast cell line, P815, were used in the present study. Cell viability was detected by CCK-8 experiment. Levels of histamine and β-hexosaminidase were measured by ELISA. miRNA expression was detected by miRNA sequencing and reverse transcription-quantitative PCR. The results showed that ultravist could increase histamine release and reduce intracellular β-hexosaminidase levels of mast cells. A total of 102 miRNAs could be significantly upregulated by ultravist stimulation. Selected candidate miRNAs for the validation included miR-19a-3p and miR-362-3p which were also increased expression following stimulation with ultravist. In conclusion, ultravist could induce mast cell activation through upregulation of miR-19a-3p and miR-362-3p. Thus, miR-19a-3p and miR-362-3p could be promising candidates for development as novel targets for preventing radiocontrast-induced allergy in the future.

Regulating TKT activity inhibits proliferation of human acute lymphoblastic leukemia cells

Among pediatric blood cancers, acute lymphoblastic leukemia (ALL) is the most common hematologic malignancy. Within ALL, T-cell acute lymphoblastic leukemia (T-ALL) accounts for 10 to 15% of all pediatric cases, and ~25% of adult cases. For T-ALL, its recurrence and relapse after treatment remain problematic. Therefore, it is necessary to develop new therapies for T-ALL. Recent studies suggested regulating energy metabolism is a novel approach to inhibit tumor growth, likely a promising treatment. Transketolase (TKT) is an important enzyme for modulating glucose metabolize in the pentose phosphate pathway (PPP). In this study, we treated T-ALL cells with different doses of niclosamide and primary T-ALL PBMCs were analyzed by RNA sequencing. T-ALL cells treated with niclosamide were analyzed with the Western blotting and TKT activity assay. Metabolism of T-ALL cells was evaluated by ATP assay and seahorse analyses. Lastly, we used a T-ALL xenograft murine model to determine effects of TKT knockdown on T-ALL tumor growth. Tumor samples were analyzed by H&E and IHC stainings. We found that niclosamide reduced T-ALL cell viability, and reduced expressions of TKT, Transketolase-Like Protein 1/2 (TKTL1/2) and transaldolase. In addition, niclosamide inhibited TKT enzyme activity, aerobic metabolism and glycolysis, finally leading to lower production of ATP. TKT knockdown inhibited tumor growth of xenograft T-ALL mice. Findings showed that niclosamide inhibits T-ALL cell growth by inhibiting TKT and energy metabolism.

Inhibition of NLRP3 Inflammasome Activation by 3H-1,2-Dithiole-3-Thione: A Potential Therapeutic Approach for Psoriasis Treatment

Psoriasis is a chronic autoimmune skin disease with a significant impact on quality of life and potential for severe comorbidities. Inflammation in the skin is induced by immune cells that overexpress pro-inflammatory cytokines, with the Th17 cell playing a crucial role. NLRP3 inflammasome activation is associated with inflammatory diseases and abnormal T cell differentiation. 3H-1,2-dithiole-3-thione (D3T), isolated from cruciferous vegetables, has anti-inflammatory effects and inhibits Th17 differentiation. This study aimed to investigate how D3T reduces skin inflammation and modulates Th17 cell differentiation by inhibiting NLRP3 inflammasome activation. In an imiquimod-induced psoriasis mouse model, D3T treatment demonstrated significant reductions in ear thickness, skin redness, and scaling compared to a control group. Our study also observed decreased expression of ki-67, NLRP3 inflammasome, and cleaved caspase-1 in skin samples, reduced levels of IL-6 and IL-17A in serum samples, and inhibition of Th17 differentiation after D3T application. D3T could also inhibit the expression of NLRP3, caspase-1, and IL-1β in TNF-α stimulated HaCaT cells. The mechanical study also revealed that D3T could inhibit NLRP3 inflammasome activation by inhibiting the JNK pathway in HaCaT cells. These results indicate that targeting NLRP3 inflammasome activation is a promising strategy in the treatment of psoriasis.

Inguinal Fat Compensates Whole Body Metabolic Functionality in Partially Lipodystrophic Mice with Reduced PPARγ Expression

Peroxisome proliferator-activated receptor γ (PPARγ) gene mutations in humans and mice lead to whole-body insulin resistance and partial lipodystrophy. It is unclear whether preserved fat depots in partial lipodystrophy are beneficial for whole-body metabolic homeostasis. We analyzed the insulin response and expression of metabolic genes in the preserved fat depots of PpargC/- mice, a familial partial lipodystrophy type 3 (FPLD3) mouse model resulting from a 75% decrease in Pparg transcripts. Perigonadal fat of PpargC/- mice in the basal state showed dramatic decreases in adipose tissue mass and insulin sensitivity, whereas inguinal fat showed compensatory increases. Preservation of inguinal fat metabolic ability and flexibility was reflected by the normal expression of metabolic genes in the basal or fasting/refeeding states. The high nutrient load further increased insulin sensitivity in inguinal fat, but the expression of metabolic genes became dysregulated. Inguinal fat removal resulted in further impairment of whole-body insulin sensitivity in PpargC/- mice. Conversely, the compensatory increase in insulin sensitivity of the inguinal fat in PpargC/- mice diminished as activation of PPARγ by its agonists restored insulin sensitivity and metabolic ability of perigonadal fat. Together, we demonstrated that inguinal fat of PpargC/- mice plays a compensatory role in combating perigonadal fat abnormalities.

Adherence to the dietary approaches to stop hypertension diet and all-cause mortality in patients with a history of heart failure

Background and aims

We investigated the association of adherence to the Dietary Approaches to Stop Hypertension (DASH) diet with all-cause mortality in patients with a history of heart failure.

Methods

We analyzed data from the National Health and Nutrition Examination Survey (NHANES). Dietary information was obtained from a 24-h dietary recall interview. Adherence to the DASH diet was assessed using the DASH score. The primary outcome was all-cause mortality which was confirmed by the end of 2011. Weighted Cox proportional hazards regression models were used to determine the hazard ratios and 95% CI for the association of the DASH score and all-cause mortality with multivariate adjustment.

Results

The median DASH score was 2 among the 832 study participants. There were 319 participants who died after a median follow-up duration of 4.7 years. A higher DASH score (>2 vs. ≤ 2) was not associated with a decrease in the risk of all-cause mortality (adjusted HR 1.003, 95% CI 0.760–1.323, p = 0.983). With respect to the components of the DASH score, a lower sodium intake was not associated with a decreased risk of mortality (adjusted HR 1.045, 95% CI 0.738–1.478, p = 0.803).

Conclusion

A higher DASH score (>2 vs. ≤ 2) was not associated with all-cause mortality in patients with heart failure.

Low-Frequency vs. Theta Burst Transcranial Magnetic Stimulation for the Treatment of Chronic Non-fluent Aphasia in Stroke: A Proof-of-Concept Study

BACKGROUND

Although low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) has shown promise in the treatment of poststroke aphasia, the efficacy of high-frequency rTMS (HF-rTMS) has yet to be determined.

PURPOSE

We investigated the efficacy of intermittent theta burst stimulation (iTBS) in ameliorating chronic non-fluent aphasia and compared it with that of LF-rTMS.

METHODS

We randomly assigned patients with poststroke non-fluent aphasia to an ipsilesional iTBS (n = 29), contralesional 1-Hz rTMS (n = 27), or sham (n = 29) group. Each group received the rTMS protocol executed in 10 daily sessions over 2 weeks. We evaluated language function before and after the intervention by using the Concise Chinese Aphasia Test (CCAT).

RESULTS

Compared with the sham group, the iTBS group exhibited significant improvements in conversation, description, and expression scores (P = 0.0004-0.031), which characterize verbal production, as well as in auditory comprehension, reading comprehension, and matching scores (P < 0.01), which characterize language perception. The 1-Hz group exhibited superior improvements in expression, reading comprehension, and imitation writing scores compared with the sham group (P < 0.05). The iTBS group had significantly superior results in CCAT total score, matching and auditory comprehension (P < 0.05) relative to the 1-Hz group.

CONCLUSION

Our study findings contribute to a growing body of evidence that ipsilesional iTBS enhances the language recovery of patients with non-fluent aphasia after a chronic stroke. Auditory comprehension was more preferentially enhanced by iTBS compared with the 1-Hz protocol. Our findings highlight the importance of ipsilesional modulation through excitatory rTMS for the recovery of non-fluent aphasia in patients with chronic stroke.

CLINICAL TRIAL REGISTRATION

[www.ClinicalTrials.gov], identifier [NCT03059225].

N-acetylgalactosamine-6-sulfatase (GALNS), Similar to Glycodelin, Is a Potential General Biomarker for Multiple Malignancies

BACKGROUND/AIM

The aim of this study was to evaluate N-acetylgalactosamine-6-sulfatase (GALNS) as a new biomarker candidate for detecting lung cancer. Glycodelin or PAEP, the serum levels of which are known to be elevated in lung and other cancers, served as a benchmark for comparison.

PATIENTS AND METHODS

A total of 170 serum samples from healthy controls and patients with pneumonia, lung cancer, breast cancer, colon cancer, liver cancer, and head and neck cancer were analyzed for the levels of GALNS and PAEP by ELISA.

RESULTS

The median serum levels of GALNS and PAEP in all cancer types as well as pneumonia patients were significantly higher than those of the healthy controls.

CONCLUSION

In addition to previously known cancers, the median serum levels of PAEP were also found to be higher in liver and head and neck cancer patients. GALNS and PAEP are promising general biomarkers for multiple cancers and deserve further evaluation.

Effects of alpha-mangostin on the expression of anti-inflammatory genes in U937 cells

Background

α-Mangostin (α-MG) is a main constituent of the fruit hull of the mangosteen. Previous studies have shown that α-MG has pharmacological activities such as antioxidant, antitumor, anti-inflammatory, antiallergic, antibacterial, antifungal and antiviral effects. This study aims to investigate the anti-inflammatory molecular action of α-MG on gene expression profiles.

Methods

U937 and EL4 cells were treated with different concentrations of α-MG in the presence of 0.1 ng/mL lipopolysaccharide (LPS) for 4 h. The anti-inflammatory effects of α-MG were measured by the levels of tumor necrosis factor (TNF)-α and interleukin (IL)-4 in cell culture media, which were determined with enzyme-linked immunosorbent assay kits. The gene expression profiles of all samples were analyzed with a whole human genome microarray, Illumina BeadChip WG-6 version 3, containing 48804 probes. The protein levels were determined by Western blotting analyses.

Results

α-MG decreased the LPS induction of the inflammatory cytokines TNF-α (P = 0.038) and IL-4 (P = 0.04). α-MG decreased the gene expressions in oncostatin M signaling via mitogen-activated protein kinase (MAPK) pathways, including extracellular signal-regulated kinases (P = 0.016), c-Jun N-terminal kinase (P = 0.01) , and p38 (P = 0.008). α-MG treatment of U937 cells reduced the phosphorylation of MAPK kinase 3 / MAPK kinase 6 (P = 0.0441), MAPK-activated protein kinase-2 (P = 0.0453), signal transducers and activators of transcription-1 (STAT1) (P = 0.0012), c-Fos (P = 0.04), c-Jun (P = 0.019) and Ets-like molecule 1 (Elk-1) (P = 0.038).

Conclusion

This study demonstrates that α-MG attenuates LPS-mediated activation of MAPK, STAT1, c-Fos, c-Jun and EIK-1, inhibiting TNF-α and IL-4 production in U937 cells.

Whole genome expression in peripheral-blood samples of workers professionally exposed to polycyclic aromatic hydrocarbons

This study aims to examine global gene expression profiles before and after the work-shift among coke-oven workers (COWs). COWs work six consecutive days and then take two days off. Two blood and urine samples in each worker were collected before starting to work after two days off and end-of-shift in the sixth day of work in 2009. Altered gene expressions (ratio of gene expression levels between end-of-shift and preshift work) were performed by a Human OneArray expression system which probes ~30,000-transcription expression profiling of human genes. Sixteen workers, all men, were enrolled in this study. Median urinary 1-hydroxypyrene (1OHP) levels (μmol/mol creatinine) in end-of-shift work were significantly higher than those in preshift work (2.58 vs 0.29, p = 0.0002). Among the 20,341 genes which passed experimental quality control, 26 gene expression changes, 7 positive and 19 negative, were highly correlated with across-the-shift urinary 1OHP levels (end-of-shift-preshift 1OHP) (p-value <0.001). The high and low exposure groups of across-the-shift urinary 1OHP levels dichotomized in ~2.00 μmol/mol creatinine were able to be distinguished by these 26 genes. Some of them are known to be involved in apoptosis, chromosome stability/DNA repair, cell cycle control/tumor suppressor, cell adhesion, development/spermatogenesis, immune function, and neuronal cell function. These findings in COWs will be an ideal model to study the relationship of PAH exposure with acute changes of gene expressions.

Abstract 3356: A controversial study on well reported liver cancer stem cell marker

Recent studies suggest that the presence of cancer stem cells (CSC) could be linked with patients’ survival. The ability of cancers to grow indefinitely has fueled the idea that cancer and stem cells may have common underlying mechanisms. It has been suggested that tumors are initiated from cancer stem cells (CSCs) with proliferation potential drives the growth of cancer. CSCs are resistant to chemotherapy and radiation. However, the suggested cancer stem cell markers in human hepatocellular carcinoma cells are variable and confused. In this study, we profiled some of the most reported CSC markers, including CD133, epithelial cell adhesion molecule (EpCAM), aldehyde dehydrogenase (ALDH), CD90, CD24, c-kit, global-H and stemness genes in eight human hepatocellular carcinoma cell lines. Through specific marker expressed cell sorting by FACs aria or magnetic beads, the CSC associated drug resistance and tumorigenicity were further evaluated. However, there is no obvious difference among parental group, marker-positive group and marker-negative group in these CSC characteristics evaluated. It seems no good correlation between reported markers in liver cancer stem cells. Therefore, presence of markers alone should be taken with caution as single prognostic parameters. Through harsh culture condition, spheroid cell grew and had been isolated, which perform CSC-like properties. Moreover, forced activation of an ESC-like gene expression program can reprogram HCC cells into CSC-like cells and achieve pathologic self-renewal. The ability to create induced cancer stem cells (iCSC) may provide opportunities to better define the biology of cancer stem cells in order to trace or eliminate them in human patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3356.

Design and implementation of robust controllers for a gait trainer

This paper applies robust algorithms to control an active gait trainer for children with walking disabilities. Compared with traditional rehabilitation procedures, in which two or three trainers are required to assist the patient, a motor-driven mechanism was constructed to improve the efficiency of the procedures. First, a six-bar mechanism was designed and constructed to mimic the trajectory of children's ankles in walking. Second, system identification techniques were applied to obtain system transfer functions at different operating points by experiments. Third, robust control algorithms were used to design Hinfinity robust controllers for the system. Finally, the designed controllers were implemented to verify experimentally the system performance. From the results, the proposed robust control strategies are shown to be effective.

Decreased PPAR gamma expression compromises perigonadal-specific fat deposition and insulin sensitivity

Mutations and polymorphisms in PPARG have been linked to adiposity and partial lipodystrophy in humans. However, how disturbances in PPARG lead to depot-specific effects on adipose tissue, as shown by the characteristic aberrant fat distribution in patients, remains unclear. By manipulating the 3'-untranslated region of the Pparg gene, we have generated mice with peroxisome proliferator-activated receptor gamma (PPAR gamma) gene expression ranging from 25% to 100% normal. Basal levels of PPAR gamma transcripts between 50% and approximately 100% had no significant effect on body weight, fat mass, and insulin sensitivity. In contrast, mice with 25% normal PPAR gamma expression exhibited reduced body weight and total fat mass, insulin resistance, and dyslipidemia. Interestingly, fat mass was selectively reduced in perigonadal depot without significant changes in inguinal and other depots. Expression of adipogenic factor CCAAT enhancer binding protein-alpha and some other metabolic genes containing peroxisome proliferator response element were reduced in a perigonadal depot-specific fashion. This was further associated with depot-specific reduction in the expression of adipokines, increased expression of TNFalpha, and increased ectopic lipid deposition in muscles. Together, these results underscore the differential sensitivity of the individual fat depots on PPAR gamma availability as an underlying mechanism of partial lipodystrophy.

Protein profilings in mouse liver regeneration after partial hepatectomy using iTRAQ technology

Liver is unique in its capability to regenerate after an injury. Liver regeneration after a 2/3 partial hepatectomy served as a classical model and is adopted frequently to study the mechanism of liver regeneration. In the present study, semiquantitative analysis of protein expression in mouse liver regeneration following partial hepatectomy was performed using an iTRAQ technique. Proteins from pre-PHx control livers and livers regenerating for 24, 48 and 72 h were extracted and inspected using 4-plex isotope labeling, followed by liquid chromatography fractionation, mass spectrometry and statistical differential analysis. A total of 827 proteins were identified in this study. There were 270 proteins for which quantitative information was available at all the time points in both biologically duplicate experiments. Among the 270 proteins, Car3, Mif, Adh1, Lactb2, Fabp5, Es31, Acaa1b and LOC100044783 were consistently down-regulated, and Mat1a, Dnpep, Pabpc1, Apoa4, Oat, Hpx, Hp and Mt1 were up-regulated by a factor of at least 1.5 from that of the controls at one time point or more. The regulation of each differential protein was also demonstrated by monitoring its time-dependent expression changes during the regenerating process. We believe this is the first report to profile the protein changes in liver regeneration utilizing the iTRAQ proteomic technique.

Measurement and analysis of ambient air particulates and ionic species for composition and concentration studies at the western coast of central Taiwan

Air-polluting aerosol samples consisting of total suspended particulates, coarse particulates (>2.5~10 μm in diameter), fine particulates (<2.5 μm in diameter), and ionic species were collected from March 2004 to January 2005 at the western coast of central Taiwan. Statistical methods such as nonparametric test and T statistical analysis were also employed to distinguish the variation difference for pollutants among four seasons in this study. Seasonal variation of ionic species SO42− in the total suspended particulates and fine particulates shows that higher composition was observed among four seasons. The results of T statistical analysis revealed that the concentrations of ionic species NO3− showed no significant changes in coarse and fine particulates among the four seasons. In addition, the results also revealed that the concentrations of ionic species Na+ showed no significant changes in coarse and fine particulates in the seasons of spring and autumn at the western coast of central Taiwan.

Hemodynamic effects of Salvia miltiorrhiza on cirrhotic rats

Salvia miltiorrhiza (Sm) administration has been shown to reduce hepatic fibrosis in rats. We investigated the hemodynamic effects of Sm on bile duct ligated (BDL) rats. Hemodynamic, histological, and vascular contractile studies were conducted in rats 4 weeks after bile duct ligation. An aqueous extract of Sm (0.2 g twice per day) or vehicle was administered for 4 weeks to BDL rats. Sm treatment in BDL rats significantly reduced histological grades of fibrosis and ameliorated the portal hypertensive state (including portal venous pressure, superior mesenteric artery blood flow, cardiac index, and total peripheral resistance) as compared with vehicle treatment. Moreover, Sm treatment enhanced the vascular sensitivity of mesenteric arteries to phenylephrine in BDL rats. Sm treatment had no effect on plasma biochemical profiles of either BDL or normal rats. Our results suggest that 4-week Sm treatment ameliorates the portal hypertensive state in BDL rats.

Hepatocellular carcinoma with Pancoast's syndrome as an initial symptom: a case report

Pancoast's syndrome refers to a condition consisting of Horner's syndrome and arm pain that is most commonly found in patients with a lung tumor of the superior sulcus invading the upper ribs or spine, lower brachial plexus and sympathetic chain. We report a 76-year-old female who had a thoracic inlet mass that presented as Pancoast's syndrome, showing profound pain, numbness and weakness of the left upper limb. Further evaluation revealed an increased level of serum alpha-fetoprotein (24278 ng/ml), cryptogenic liver cirrhosis and primary hepatocellular carcinoma with protruding T3 vertebra metastasis that resulted in Pancoast's syndrome. To our knowledge, it is a rare case and only one case has been reported previously.

O-Linked N-Acetylglucosamine and Cancer: Messages from the Glycosylation of C-Myc

Altered protein glycosylation is known to correlate with tumorigenesis, but its role remains enigmatic. Cells transformed by altered oncogene or tumor suppressor gene expression often also show changes of carbohydrate on cell surface glycoconjugates which correlate with the potential for tumor invasion and metastasis. In recent years, many oncogene and tumor suppressor gene products, such as c-Myc, SV40 large T antigen, and p53, were shown to be modified by O-GlcNAc. O-GlcNAc is a form of protein glycosylation found almost exclusively in the nucleus and cytoplasm of eukaryotic cells. The known O-GlcNAc-bearing proteins are phosphoproteins and form reversible multimeric complexes. O-GlcNAc modification is dynamic and appears to have a reciprocal relationship with protein phosphorylation. The enzymes which catalyze O-GlcNAc addition and removal have been characterized and used as effective tools in O-GlcNAc studies. It is of great interest in the future to investigate the alteration of O-GlcNAc in different cancers since addition/removal of O-GlcNAc on oncoproteins, tumor suppressor proteins, and other tumor-related proteins very likely plays a key role in the pathogenesis of tumors.

Well-differentiated fetal adenocarcinoma of the lung

We describe the case of a 43-year-old woman with a tumor shadow in the upper lobe of the left lung. The tumor was initially suspected to be a carcinoid tumor, following percutaneous needle biopsy. Subsequently, a left upper lobectomy was performed, and a well-differentiated fetal adenocarcinoma was diagnosed histologically. Unlike the biphasic epithelial and stromal features of pulmonary blastoma, it was composed solely of malignant glands of embryonal appearance.

Transverse testicular ectopia: preoperative diagnosis by ultrasonography

Transverse testicular ectopia (TTE) is a rare anomaly. We report the first case of TTE described in Taiwan. The physical examination, ultrasonography (US), and laparoscopy revealed both testes in the left hemiscrotum, and surgical correction was performed. This case was diagnosed preoperatively by US, which can offer an easy, safe, and convenient alternative in the preoperative diagnosis of TTE. The possible mechanism for this anomaly and the literature are reviewed.

Pulmonary alveolar-septal amyloidosis presenting as heart failure with unilateral pleural effusion: a case report

We report a case of pulmonary alveolar-septal amyloidosis associated with chylothorax and paraproteinemia initially presenting as congestive heart failure with unilateral pleural effusion. A 72-year-old man was initially diagnosed with congestive heart failure based on the correlation of clinical manifestation and chest radiography. Concentric left ventricular hypertrophy with mild hypokinesis of the left ventricle was found on cardiac echography. Thoracocentesis was performed for right-sided pleural effusion, which persisted despite medical treatment; chylous exudate was aspirated. Because the etiology of the exudative pleural effusion was undetermined, the patient underwent a thoracotomy that showed pulmonary alveolar-septal amyloidosis. Immunoglobulin M paraproteinemia was identified by serum immunoelectrophoresis. We conclude that it is imperative to search for the cause of an undetermined exudative pleural effusion, with particular attention to chylothorax and amyloidosis as the differential diagnoses.

Ultrasonography for inguinal hernias in boys

BACKGROUND/PURPOSE

History taking and physical examination alone no longer meet the surgeon's need in the diagnosis of inguinal hernia. Ultrasonography (US) provides a good and safe diagnostic tool for inguinal hernias in boys.

METHODS

From 1995 to 1997, 244 boys with inguinal hernias (41 bilateral and 203 unilateral), received preoperative US on both groins to confirm the diagnosis. Those with positive US findings, such as viscera or fluid in inguinal canal or widening of the internal inguinal ring, underwent surgery.

RESULTS

The accuracy of diagnosis with US and clinical assessment were 97.9% and 84%, respectively. More than 95% of widening of internal inguinal rings (>4 mm) proved to be hernias. There were two direct inguinal hernias and two femoral hernias, which were misdiagnosed by clinical examination, but proved to be diagnosed correctly by US.

CONCLUSIONS

US serves as a noninvasive and highly accurate diagnostic tool for inguinal hernias in boys. Using 4 mm as the upper limit of the normal diameter of the internal inguinal ring, an occult inguinal hernia can be easily detected before surgery.

Squamous metaplasia of the endometrium associated with HPV 6 and 11

Although uncommon in the endometrium, squamous metaplasia, dysplasia, and squamous carcinoma have been observed. Associated human papillomavirus (HPV) infection is also unusual, due at least in part to the fact that HPV requires specific characteristics of the target epithelium for infectivity. We report a case of extensive squamous metaplasia with focal low-grade squamous intraepithelial neoplasia of the endometrium coexistent with low-grade cervical intraepithelial neoplasia and an invasive squamous carcinoma of the vagina. In situ hybridization studies revealed HPV types 6 and 11 in both the cervical and endometrial lesions. This is the first report to date to demonstrate squamous epithelial metaplasia and dysplasia of the endometrium, associated with HPV DNA of viruses typically of low oncogenic potential.

Prevalence of human papillomavirus in middle ear carcinoma associated with chronic otitis media

Squamous cell carcinoma of the middle ear (MESCC) is an uncommon tumor and is associated with a history of long-term chronic otitis media (COM) in most cases. Although the human papillomaviruses (HPVs) have been implicated in many human neoplasms, its role in the pathogenesis of MESCC has not been studied. Polymerase chain reaction (PCR) using consensus primers for the detection of HPV types 6, 11, 16, 18, 31, 33, 52b, and 58 was applied in screening fourteen cases of MESCC from archival material. Further subtyping was performed by restriction enzyme digestion of PCR products and by in situ hybridization method on tissue sections. Of the fourteen cases of MESCC, eleven were found to have HPV DNA. HPV-16 was detected in all positive cases. Five cases revealed both HPV-16 and -18. A history of long-term COM (> 3 years) was found in thirteen of the cases. This is the first report to localize HPV-16/18 in MESCC on both the tissue level and the molecular level. The high prevalence of HPV in COM-associated MESCC therefore provides a good model to explain the pathogenesis of chronic-inflammation-related human malignancies.

Rapid spongiform degeneration of the cerebrum and cerebellum in Creutzfeldt-Jakob encephalitis: serial MR findings

We report the cerebral MR imaging findings in a patient with pathologically proved Creutzfeldt-Jakob disease in whom predominant gray and white matter degeneration was seen within 1 year of symptom onset. The initial MR signal abnormalities in the basal ganglia were subtle. A follow-up MR examination revealed diffuse cerebral and cerebellar atrophy and demyelination.

Optic atrophy and cerebral infarcts caused by methanol intoxication: MRI

We present the MRI findings of cerebral and optic pathway damage in the acute and subacute stages of methanol intoxication. In the acute stage, CT and MRI showed bilateral haemorrhagic necrosis of the corpus striatum and infarcts in the anterior and middle cerebral arterial territories. MRI in the subacute stage demonstrated atrophy of the optic chiasm and prechiasmatic optic nerves in addition to the cerebral infarcts. The patient survived, with total blindness.

Pericerebral fluid collection: differentiation of enlarged subarachnoid spaces from subdural collections with color Doppler US

PURPOSE

To determine if the cerebral cortical vain sign seen on magnetic resonance (MR) images can be used with color Doppler ultrasound (US) to differentiate enlarged subarachnoid space from subdural collection.

MATERIALS AND METHODS

Eighteen infants with pericerebral fluid collection were prospectively examined with color Doppler US and MR imaging. Patients were classified into two groups: group A, with positive cortical vein sign (visualization of color-coded cortical veins that cross fluid collections at cerebral convexities); and group B, without the sign.

RESULTS

Positive cortical vein sign was seen at US in 12 patients (group A): nine with benign enlargement of subarachnoid spaces, two with brain atrophy, and one with meningococcal meningitis. The veins were displaced and embedded within the echogenic pia-arachnoid that surrounds the brain or were trapped in the subarachnoid spaces between the neo-membrane and cortical surface (group B, negative cortical vein sign) in four patients with meningitis, two victims of child abuse, and one patient with leukemia. Findings from subsequent MR imaging confirmed the color Doppler US findings.

CONCLUSION

Color Doppler US depiction of the cortical vain sign appears to be as effective as MR imaging in differentiating enlargement of the subarachnoid fluid space from subdural effusion.

Inguinal hernia in children: US versus exploratory surgery and intraoperative contralateral laparoscopy

PURPOSE

To analyze the value of ultrasound (US) in the preoperative recognition of clinically apparent and inapparent inguinal hernias (or patent processus vaginalis).

MATERIALS AND METHODS

Two hundred sixty children (197 boys, 63 girls), in whom a clinical diagnosis of inguinal hernia (226 unilateral hernias, 34 bilateral hernias) had been made, underwent US examination with a 7.0-MHz linear-array transducer. The contralateral internal inguinal ring was evaluated by means of intraoperative laparoscopy in 141 patients. The 197 boys were grouped together by age (< 12 months, 12-24 months, 24-48 months, 48-72 months, and > 72 months).

RESULTS

In the 260 patients who underwent inguinal herniorrhaphy, 246 hernias (95%) were correctly diagnosed at US based on criteria of an internal inguinal ring width greater than 4 mm in diameter or the presence of fluid or organs in the inguinal canal at rest or during straining. A total of 473 hernias were confirmed surgically and 459 (97%) hernias were correctly detected at US. A statistically significant difference in the mean width of the internal inguinal ring of the five age groups was found between patients at rest and during straining (P < .05) in US measurement of the 197 surgically proved cases in boys.

CONCLUSION

US is a noninvasive, readily available, and highly accurate (95%) method for evaluating the presence of inguinal hernia in children at risk, especially when the clinical findings are equivocal or normal. US can provide an objective measure in determining the advisability of exploratory inguinal surgery in such cases.

Mucosal IFN-gamma gene transfer inhibits pulmonary allergic responses in mice

Th2 cytokines are associated with the airway inflammation and hyperreactivity in allergic asthma and are potential targets for developing novel therapies. The efficacy of a mucosal cytokine-gene transfer approach was examined in a mouse model for allergic asthma. We showed first that mucosal IFN-gamma gene transfer results in a significant expression of IFN-gamma in the pulmonary epithelium. Significantly, this approach inhibits both Ag- and Th2-cell-induced pulmonary eosinophilia and airway hyperreactivity. These findings suggest that mucosal IFN-gamma gene transfer is effective in modulating pulmonary allergic responses and provides a basis for developing a novel therapeutic approach.

Mucosal IFN-gamma gene transfer inhibits pulmonary allergic responses in mice

Th2 cytokines are associated with the airway inflammation and hyperreactivity in allergic asthma and are potential targets for developing novel therapies. The efficacy of a mucosal cytokine-gene transfer approach was examined in a mouse model for allergic asthma. We showed first that mucosal IFN-gamma gene transfer results in a significant expression of IFN-gamma in the pulmonary epithelium. Significantly, this approach inhibits both Ag- and Th2-cell-induced pulmonary eosinophilia and airway hyperreactivity. These findings suggest that mucosal IFN-gamma gene transfer is effective in modulating pulmonary allergic responses and provides a basis for developing a novel therapeutic approach.

Retinal detachment in U.S. Air Force flyers

Retinal detachment is a serious ocular condition, even though 85% can be repaired permanently. Long-term complications include decreased or loss of vision, redetachment, visual field changes, and proliferative vitreoretinpathy. To assess the effect of retinal detachment on flying careers, we reviewed the records of all aviators with a rhegmatogenous retinal detachment who were examined by the Ophthalmology Branch of the Aerospace Medicine Directorate at the Armstrong Laboratory (formerly the USAF School of Aerospace Medicine) from 1967-1986. Of the 19 flyers, 12 were returned to flying duties; only 2 were disqualified for ocular reasons alone. In 10 flyers, the detachments were previously undiagnosed. Associated vitreoretinal pathology was common in both eyes (42%). All received some type of treatment. Redetachment occurred in 4 flyers, but the overall final reattachment rate was 95%. Final posttreatment visual acuities were 20/20 or better in 16 flyers. Treatment-induced myopia was common. Many flyers enjoyed long flying careers after detachment repairs.

MR of the cerebral operculum: abnormal opercular formation in infants and children

PURPOSE

To evaluate abnormalities of the cerebral operculum in infants and children and to propose the embryogenic basis of abnormal opercular formation as determined from MR imaging findings.

METHODS

Eighty-six infants and children who had abnormally wide interopercular distances and/or distorted opercular topography seen on MR images were studied retrospectively. Clinically, patients presented with tonal abnormalities, macrocephaly, microcephaly, seizures, developmental delay, cerebral palsy, or facial dysmorphism. The abnormal opercula were compared with developing opercula at different stages of gestation.

RESULTS

Among the 86 infants and children, two categories of opercular abnormalities were identified: an underdeveloped operculum (n = 64) and a malformed operculum (n = 22). The malformed operculum was further classified into three subtypes: nonformation of the operculum with lissencephaly (n = 1, 1%), abnormal opercular formation with pachygyria (n = 11, 13%), and nonformation or abnormal formation of the operculum without pachygyria or lissencephaly (n = 10, 12%). Two subtypes of the underdeveloped operculum were identified: an open operculum without a normal insula (n = 6, 7%) and an open operculum with a normal insula (n = 58, 67%). The five subtypes of abnormal opercular configuration showed a range of maturity that was comparable to the developing operculum at different ages.

CONCLUSION

Opercular anomalies appear to follow sequentially predetermined normal steps in development. Arrest in opercular development or malformation may occur after an initial insult. MR imaging is the method of choice by which to identify these abnormalities.

Hypoxic-ischaemic injury of the spinal cord in systemic shock: MRI

The imaging characteristics of concurrent spinal cord injury in children with hypoxic-ischaemic injury of the brain have not been described. We present the MRI findings of hypoxic-ischaemic injury of the brain and spinal cord following hypovolaemic shock in a 2-year-old girl.

Childhood leukemia: central nervous system abnormalities during and after treatment

PURPOSE

To document the radiologic abnormalities seen in the central nervous system (CNS) during and after treatment of childhood leukemia.

METHODS

MR images (19 patients) and CT scans (12 patients) were reviewed retrospectively in 19 children and adolescents with neurologic complications of leukemia or its treatment. Patients were divided into two groups: the first included those with disease-related complications of leukemia, such as meningeal and parenchymal leukemia, chloroma, and cerebrovascular disorders; the second included patients with treatment-related neurotoxicity and infection caused by immunocompromised states. Pathologic confirmation of the CNS lesions was obtained in eight patients. Factors that predisposed to the development of tumor-related or treatment-related complications were determined by reviewing the medical records.

RESULTS

Among the 19 patients, 10 had two or more different CNS abnormalities found on CT scans or MR images. The imaging abnormalities seen in 12 patients during treatment included sinus thrombosis (n = 3), transient gray or white matter ischemia (n = 2), presumed disseminated microinfarcts (n = 1), cerebral hemorrhage or infarct (n = 3), inflammatory demyelinating polyradiculoneuropathy (n = 1), infections (n = 4, 2 bacterial and 2 fungal), and meningeal leukemia (n = 2). After therapy, seven patients had CNS imaging abnormalities, including secondary brain tumors (2 malignant gliomas and 1 CNS lymphoma), spinal chloroma (n = 1), necrotizing leukoencephalopathy and mineralizing microangiopathy (n = 3), cerebral mucormycosis (n = 1), spontaneous intracranial hemorrhage (n = 3), and spinal meningeal leukemia (n = 1).

CONCLUSION

The wide spectrum of CNS abnormalities that occur during and after treatment for leukemia is related to the inherent risk of the leukemia itself, to the treatment method, and to the duration of survival. Because many neurologic complications of leukemia are treatable, early diagnosis is essential.

Cerebral MR manifestations of Pompe disease in an infant

We present the cerebral MR findings of a 5-month-old girl with biopsy-proved Pompe disease and discuss the imaging characteristics with known central nervous system disease.

Epididymo-orchitis in an infant resulting from Escherichia coli urinary tract infection

Epididymo-orchitis (EO) is said to be extremely rare in infants and children. It is usually diagnosed after scrotal exploration for symptoms which mimic manifestations between EO and torsion of the cord and its appendage. The pathophysiologic mechanisms for the development of EO are not well known. Although some causative agents of EO have been reported, in most cases there was no clear etiology. We report a 3-month-old male infant who had been well until the day prior to admission when irritability, left testicular swelling, scrotal erythema with a hot sensation were noted by his mother. He was treated medically after excluding the possibility of an emergent surgical condition (such as torsion of the cord and its appendage, or incarcerated hernia) by means of physical examinations, abdominal and inguino-scrotal sonography, laboratory studies, and testicular radionuclide scintigraphy. A catheterized sample of urine for culture yielded Escherichia coli. There was the possibility that the EO was caused by hematogenous rather than local spread from an infection of the urinary tract. He was treated with a 10-day course of intravenous cefazolin and amikacin. Following this, he improved clinically and a repeat catheterized urine sample remained sterile on culture. In addition, a bilateral inguinal hernia and hydrocele were detected by inguino-scrotal sonography and were operated on the 11th hospital day. He was discharged on the 16th day of hospitalization and remained well 11 months after discharge.

MR of the cerebral operculum: topographic identification and measurement of interopercular distances in healthy infants and children

PURPOSE

To evaluate the role of axial, coronal, and sagittal MR in identification of surface landmarks of the cerebral operculum and to determine the reference values of interopercular distances of each hemisphere in healthy infants and children on MR images.

METHODS

Two hundred fourteen cerebral opercula of 35 healthy infants and 72 healthy children were retrospectively evaluated from 107 routine MR brain examinations. The surface landmarks of the operculum and interopercular distances of each hemisphere, which were subjectively divided into anterior interopercular distance (anterior sylvian width) and posterior interopercular distance (posterior sylvian width), were recorded from axial, coronal, and sagittal MR images, respectively. The mean value of anterior interopercular distance of each hemisphere was obtained by averaging two linear measurements of the anterior sylvian width from lateral, sagittal, and axial planes of the same side. Likewise, the posterior interopercular distance of each side of the brain was obtained from averaging of two measurements on lateral, sagittal, and coronal planes.

RESULTS

The landmarks of the operculum were best identified by sagittal MR, followed by axial and coronal images. The average values of left anterior interopercular distance, right anterior interopercular distance, left posterior interopercular distance, and right posterior interopercular distance in infants were 1.9 +/- 1.3, 1.6 +/- 1.1, 0.4 +/- 0.7, and 0.2 +/- 0.4 mm, and in children, 0.9 +/- 1.3, 1.0 +/- 1.4, 0.03 +/- 0.23, and 0.01 +/- 0.07 mm, respectively. Infants showed significantly wider interopercular distances than children. Left anterior interopercular distance was significantly wider than right in infants, but not in children. Male children displayed a more significant increase in anterior interopercular distance than did female children. There was no statistic difference in measurements of anterior interopercular distance and posterior interopercular distance between female and male infants.

CONCLUSIONS

The operculum should be evaluated with MR in three planes. Infants may show conspicuous sylvian fissures that should not exceed 4.5 mm (mean + 2 SD) anteriorly on axial and sagittal planes and 1.8 mm posteriorly on sagittal and coronal planes. Healthy children who have fully developed opercula should have an anterior interopercular distance of no more than 3.5 mm and a posterior interopercular distance of 0.5 mm.

c-Myc is glycosylated at threonine 58, a known phosphorylation site and a mutational hot spot in lymphomas

c-Myc is a helix-loop leucine zipper phosphoprotein that heterodimerizes with Max and regulates gene transcription in cell proliferation, cell differentiation, and programmed cell death. Previously, we demonstrated that c-Myc is modified by O-linked N-acetylglucosamine (O-GlcNAc) within or nearby the N-terminal transcriptional activation domain (Chou, T.-Y., Dang, C.V., and Hart, G.W. (1995) Proc. Natl. Acad. Sci. U.S.A. 92, 4417-4421). In this paper, we identified the O-GlcNAc attachment site(s) on c-Myc. c-Myc purified from sf9 insect cells was trypsinized, and its GlcNAc moieties were enzymically labeled with [3H]galactose. The [3H]galactose-labeled glycopeptides were isolated by reverse phase high performance liquid chromatography and then subjected to gas-phase sequencing, manual Edman degradation, and laser desorption/ionization mass spectrometry. These analyses show that threonine 58, an in vivo phosphorylation site in the transactivation domain, is the major O-GlcNAc glycosylation site of c-Myc. Mutation of threonine 58, frequently found in retroviral v-Myc proteins and in human Burkitt and AIDS-related lymphomas, is associated with enhanced transforming activity and tumorigenicity. The reciprocal glycosylation and phosphorylation at this biologically significant amino acid residue may play an important role in the regulation of the functions of c-Myc.

A link between increased transforming activity of lymphoma-derived MYC mutant alleles, their defective regulation by p107, and altered phosphorylation of the c-Myc transactivation domain

The c-Myc protein is a transcription factor with an N-terminal transcriptional regulatory domain and C-terminal oligomerization and DNA-binding motifs. Previous studies have demonstrated that p107, a protein related to the retinoblastoma protein, binds to the c-Myc transcriptional activation domain and suppresses its activity. We sought to characterize the transforming activity and transcriptional properties of lymphoma-derived mutant MYC alleles. Alleles encoding c-Myc proteins with missense mutations in the transcriptional regulatory domain were more potent than wild-type c-Myc in transforming rodent fibroblasts. Although the mutant c-Myc proteins retained their binding to p107 in in vitro and in vivo assays, p107 failed to suppress their transcriptional activation activities. Many of the lymphoma-derived MYC alleles contain missense mutations that result in substitution for the threonine at codon 58 or affect sequences flanking this amino acid. We observed that in vivo phosphorylation of Thr-58 was absent in a lymphoma cell line with a mutant MYC allele containing a missense mutation flanking codon 58. Our in vitro studies suggest that phosphorylation of Thr-58 in wild-type c-Myc was dependent on cyclin A and required prior phosphorylation of Ser-62 by a p107-cyclin A-CDK complex. In contrast, Thr-58 remained unphosphorylated in two representative mutant c-Myc transactivation domains in vitro. Our studies suggest that missense mutations in MYC may be selected for during lymphomagenesis, because the mutant MYC proteins have altered functional interactions with p107 protein complexes and fail to be phosphorylated at Thr-58.

Glycosylation of the c-Myc transactivation domain

O-linked N-acetylglucosamine (O-GlcNAc) is an abundant and dynamic posttranslational modification composed of a single monosaccharide, GlcNAc, glycosidically composed of a single monosaccharide, GlcNAc, glycosidically linked to the side-chain hydroxyl of serine or threonine residues. Although O-GlcNAc occurs on a myriad of nuclear and cytoplasmic proteins, only a few have thus far been identified. These O-GlcNAc-bearing proteins are also modified by phosphorylation and form reversible multimeric complexes. Here we present evidence for O-GlcNAc glycosylation of the oncoprotein c-Myc, a helix-loop-helix/leucine zipper phosphoprotein that heterodimerizes with Max and participates in the regulation of gene transcription in normal and neoplastic cells. O-GlcNAc modification of c-Myc is shown by three different methods: (i) demonstration of lectin binding to in vitro translated protein using a protein-protein interaction mobility-shift assay; (ii) glycosidase or glycosyltransferase treatment of in vitro translated protein analyzed by lectin affinity chromatography; and (iii) direct characterization of the sugar moieties on purified recombinant protein overexpressed in either insect cells or Chinese hamster ovary cells. Analyses of serial deletion mutants of c-Myc further suggest that the O-GlcNAc site(s) are located within or near the N-terminal transcription activation/malignant transformation domain, a region where mutations of c-Myc that are frequently found in Burkitt and AIDS-related lymphomas cluster.

Bilophila wadsworthia isolated from clinical specimens in Taiwan

Bilophila wadsworthia, a newly discovered anaerobic gram-negative species, has been found in such various clinical specimens as bile, pus, blood et cetera, in addition to appendicitis specimens. The formation of black center colonies in bacteroides bile esculin (BBE) agar is one of the important characteristics of the species.

Traumatic tension pneumocephalus--intracerebral pneumatocele: a case report

An 18-year-old Chinese man, suffering from head injury in a motorcycle accident, with right traumatic frontal intracerebral hemorrhage and frontal bone fractures, underwent emergency craniotomy with evacuation of hematoma at a local out-patient clinic and three months later, he suffered from CSF rhinorrhea. Headache, nausea and vomiting developed a week prior to admission. Tension pneumocephalus was diagnosed by computed tomography (CT) scan and plain skull X-ray. The fistula tract of the ethmoid sinus was investigated by radioisotope albumin (RISA) cisternography. The patient subsequently underwent emergency craniotomy for decompression. During the operation, we found that the intracerebral pneumatocele in the right frontal lobe communicated with the ipsilateral ethmoidal sinus, through which extracranial air ingressed and CSF egressed. This pneumatocele was unroofed and the fistula was temponaded by pericranial muscles and the Gelfomas sealed by tissue glue. Finally duraplasty was performed. Follow-up CT scan revealed that pneumocephalus subsided and the patient was cured of CSF rhinorrhea on discharge. As a surgical emergency, tension pneumocephalus can be successfully treated only by early diagnosis and early treatment.

Soft tissue chondroma: case report

Soft tissue chondromas are relatively rare benign tumors, while as osseous chondromas are more commonly found. Although these tumors resemble many other soft tissue lesions, they can usually be differentiated. A review of literature is presented, and clinical manifestations and roentgenographic features are also discussed. An important point to note is that this tumor is benign and spares the patient unnecessary radical therapy.

[Castleman's disease: 6 cases report]

The authors present six cases of Castleman's disease. One was located in the left middle lung near the lung root, one in the right posterior mediastinum, one in the gallbladder fossa, one in the left perinephric space, and the last two in the mesenteric region. All the hyaline-vascular type showed good enhancement after contrast medium injection. The only one case of plasma cell type located in mesentery was not enhanced after contrast injection. Ultrasound of abdomen was performed in one of the six patients, which showed homogeneous and hypoechoic in echo-pattern.

Primary malignant rhabdoid tumor of the brain: CT characteristics

Primary malignant rhabdoid tumor of the brain is rare. The CT manifestations and differential diagnosis are discussed in one pathologically proven case.

Clear cell sarcoma of tendons and aponeuroses (malignant melanoma of soft parts): report of 2 cases

Clear cell sarcoma of tendons and aponeuroses (CCSTA, malignant melanoma of soft parts), first described by Enzinger in 1965, is a rare and slow-growing soft tissue tumor mainly affecting the extremities of young adults. The tumor is believed to be a tumor of melanocyte, although its histogenesis is not definitely established. Here we report 2 cases of CCSTA with typical clinical and pathological features. A tumor grew from the right ankle of a 32-year-old man (case 1) and from the left foot of an 18-year-old woman (case 2). The tumors were deep seated and intimately bound to tendons or aponeuroses without involvement of the overlying skin. Grossly, they were greyish white, variegated with brown or black patches. Histologically, the tumor cells were arranged in nests or fascicles and composed of fusiform or polygonal cells with clear cytoplasm. Ultrastructurally, they consisted of closely apposed cells with intracytoplasmic melanosomes. Case 1 was found to have distant metastases within 6 months and died 1 year later. Case 2 received postoperative radiotherapy and was free of recurrence or metastasis 14 months after operation. The treatment of CCSTA should include radical excision, radiotherapy, and chemotherapy. The prognosis is poor.

Intracranial malignant rhabdoid tumor: report of one case

A 4-year-old boy presented with anorexia, headache, and poor spirits was found to have tumors in posterior fossa and suprasellar region which enclosed by CT scan of brain. Bilateral suboccipital craniotomy was performed by neurosurgeon. The pathological report revealed the tumor was malignant rhabdoid tumor. The patient died two and one half months after diagnosis in spite of surgical resection and radiotherapy of the tumor.

Chiral polymeric reagents for off-line and on-line derivatizations of enantiomers in high-performance liquid chromatography with ultraviolet and fluorescence detection: an enantiomer recognition approach

Optically active and detector-sensitive polymeric reagents have been synthesized, loadings determined, derivatizations/separations/detection optimized, and applications to simple amines and amino alcohols described. Such reagents have been designed to contain different chiral centers, usually amino acids, leashed via an activated ester attachment to an insoluble, structurally rigid, organic polymer backbone. 9-Fluorenylmethyl (FMOC) moieties chemically bonded to the amino acids were used as ultraviolet (UV) and fluorescence (FL) sensitive detector probes to the final diastereomers of enantiomer substrates. Such diastereomers can be readily separated by isocratic or gradient elution normal-phase methods. The kinetics for diastereomer formation have been determined, and final UV/FL responses for known mixtures of enantiomers have been compared to demonstrate overall validity of the method. Minimum detection limits, linearity of calibration plots, dual detector responses, and linear diode array spectra and absorbance ratios have also been demonstrated. In some cases, authentic standards have been prepared to calculate absolute percent derivatizations for specific enantiomer pairs. The overall approach permits, for the very first time, off-line or on-line precolumn derivatization for the formation of diastereomers having unique detector properties. It has been proven that the rates and rate constants for such formations are identical for at least those pairs of enantiomers studied. Separations are base-line or near-base-line, permitting accurate and precise quantitative determinations, by both UV and FL, of enantiomer/optical purity and chemical purity.