Micellar electrokinetic chromatography separations of dynorphin peptide analogs

Prodynorphin is a precursor that has multiple cleavage sites to release various dynorphin opioid peptides. The dynorphin analogs used in this study have 18 amino acid residues. A series of dynorphin-like peptides, differing by a single residue (alanine substitution) were assembled by Fmoc solid-phase procedures and purified by preparative high performance liquid chromatography (HPLC). Separation of the Ala-scan dynorphin analogs was investigated by micellar electrokinetic chromatography (MEKC) employing anionic, cationic and zwitterionic surfactants. The role of electrostatic and hydrophobic forces in analyte-surfactant interactions is discussed with respect to the observed elution patterns. Separation of all dynorphin analogs by MEKC using a zwitterionic surfactant shows this technique to be powerful for separating closely related peptide species. It also demonstrates the potential for using MEKC for the prescreening of peptide libraries to determine their biological activity toward specific receptors. Results from the separation of dynorphin analogs by free solution and ion-pairing capillary electrophoresis are also presented.

Subtilase-like pro-protein convertases: from molecular specificity to therapeutic applications

Limited proteolysis of most large protein precursors is carried out in vivo by the subtilisin-like pro-protein convertases. Many important biological processes such as peptide hormone synthesis, viral protein processing and receptor maturation involve proteolytic processing by these enzymes, making them potential targets for the development of novel therapeutic agents. However, the efficient development of such molecules requires a better understanding of the molecular mechanisms of proteolytic protein processing. Herein, we review the most recent findings on the molecular aspects of subtilisin-like convertase activity, such as the structural analysis of the proteases, the mechanisms of enzyme/substrate specificity, their interaction with other proteins such as 7B2, and the comparative tissue and cellular distribution of the enzymes and their substrates. These data are then used as a background for the review of the known biological functions of subtilisin-like pro-protein convertases, the reported clinical cases involving proteolytic processing defects and, finally, the ongoing development of new therapeutic inhibitor molecules based on this knowledge.

Expression of syndecan-1 in inflammatory bowel disease and a possible mechanism of heparin therapy

Heparin apparently aids healing in ulcerative colitis although its mechanism of action is unknown. The purpose of this study was to investigate the hypothesis that heparin functions as a coreceptor molecule for basic fibroblast growth factor, a role usually performed by heparan sulfate chains on syndecan-1. A marked reduction of syndecan-1 immunostaining was found in reparative epithelium from inflammatory bowel disease patients. Removal of heparan sulfate on gastrointestinal epithelial cells in vitro reduced the proliferative response to basic fibroblast growth factor. The response to basic fibroblast growth factor was completely restored by the addition of heparin. Loss of syndecan-1 expression occurs in the regenerative mucosa in inflammatory bowel disease. Although this may facilitate tissue motility, its loss probably adversely affects the ability of cells to bind basic fibroblast growth factor. The present data show that heparin may substitute the loss of functional activity of syndecan-1 in the binding of basic fibroblast growth factor.

Narcolepsy and other causes of excessive daytime sleepiness

Narcolepsy is a chronic disorder characterized by excessive daytime sleepiness, cataplexy, and other auxiliary symptoms. An interview can ascertain specific symptomatology, whereas a polysomnogram can reveal distinct clinical features. The clinical and laboratory evaluation together enable an accurate diagnosis of narcolepsy. This diagnosis includes a wide spectrum of symptom combinations. Treatment of narcolepsy should include the empathic guidance of a sleep clinician, an emphasis on sleep hygiene, and in many cases pharmacotherapy.

Health-related quality of life and tamoxifen in breast cancer prevention: a report from the National Surgical Adjuvant Breast and Bowel Project P-1 Study

PURPOSE

This is the initial report from the health-related quality of life (HRQL) component of the National Surgical Adjuvant Breast and Bowel Project Breast Cancer Prevention Trial. This report provides an overview of HRQL findings, comparing tamoxifen and placebo groups, and advice to clinicians counseling women about the use of tamoxifen in a prevention setting.

PATIENTS AND METHODS

This report covers the baseline and the first 36 months of follow-up data on 11,064 women recruited over the first 24 months of the study. Findings are presented from the Center for Epidemiological Studies-Depression Scale (CES-D), the Medical Outcomes Study 36-Item Short Form Health Status Survey (MOS SF-36) and sexual functioning scale, and a symptom checklist.

RESULTS

No differences were found between placebo and tamoxifen groups for the proportion of participants scoring above a clinically significant level on the CES-D. No differences were found between groups for the MOS SF-36 summary physical and mental scores. The mean number of symptoms reported was consistently higher in the tamoxifen group and was associated with vasomotor and gynecologic symptoms. Significant increases were found in the proportion of women on tamoxifen reporting problems of sexual functioning at a definite or serious level, although overall rates of sexual activity remained similar.

CONCLUSION

Women need to be informed of the increased frequency of vasomotor and gynecologic symptoms and problems of sexual functioning associated with tamoxifen use. Weight gain and depression, two clinical problems anecdotally associated with tamoxifen treatment, were not increased in frequency in this trial in healthy women, which is good news that also needs to be communicated.

Repeated nocturnal sleep latencies in narcoleptic, sleepy and alert subjects

OBJECTIVES

The purpose of this study was to assess nocturnal sleep latencies among narcoleptics.

METHODS

Thirteen narcoleptics and matched sleepy and alert controls participated in this study. Subjects were awakened three times on each of two experimental nights. The latencies to sleep and rapid eye movement sleep were evaluated at the beginning of the night and following each experimental awakening.

RESULTS

The alert group (AG) had a significantly longer mean nocturnal sleep latency than the narcoleptic (NG) and sleepy groups (SG). The sleep latencies at 23:00 and 01:10 h were significantly longer than the latencies at 03:10 and 05:10 h. The interaction between group and time of night demonstrated longer latencies at 23:00 and 03:10 h for the AG when compared to the SG and the NG. At 01:10 and 05:10 h all groups had comparable latencies. The number of subjects in the NG who had multiple sleep onset REM periods (SOREMPs) was significantly higher than in either the AG or the SG.

CONCLUSIONS

Narcoleptics were found to have a heightened propensity to fall asleep and increased number of SOREMPs during nocturnal sleep opportunities. These characteristics are consistent with the daytime polysomnographic findings known in this patient population.

Interpreting the clinical significance of the differential inhibition of cyclooxygenase-1 and cyclooxygenase-2

The International Consensus Meeting on the Mode of Action of COX-2 Inhibition (ICMMAC) brought together 17 international experts in arthritis, gastroenterology and pharmacology on 5 6 December 1997. The meeting was convened to provide a definition of COX-2 specificity and to consider the clinical relevance of COX-2-specific agents. These compounds are a new class of drugs that specifically inhibit the enzyme COX-2 while having no effect on COX-1 across the whole therapeutic dose range. The objectives of the meeting were to review the currently available data regarding the roles and biology of COX-1 and COX-2, and to foster a consensus definition on COX-2 specificity. At the present time, no guidelines exist for the in vitro and in vivo assessment of COX specificity, and it was felt that consensus discussion might clarify some of these issues. The meeting also reviewed recent clinical data on COX-2-specific inhibitors. The following article reflects discussion at this meeting and provides a consensus definition of COX-2-specific inhibitors.

Heparin, cell adhesion, and pathogenesis of inflammatory bowel disease

Tissue repair involves a close interplay between growth factors and cell adhesion molecules. The normal healing process may be disrupted by pathophysiological states such as inflammation, due to loss of growth factors, cell adhesion molecules, or both, which results in a reduced rate of healing. Such events may occur in inflammatory bowel disease during mucosal restitution. We postulate that the beneficial response to heparin observed in inflammatory bowel disease may result from mechanisms in addition to anticoagulation. These include the restoration of high-affinity receptor binding by antiulcerogenic growth factors, such as basic fibroblast growth factor, that normally rely on the presence of heparan sulphate proteoglycans, such as syndecan-1, as co-receptors. Loss of syndecan-1 has been observed in the ulcerated mucosa of patients with inflammatory bowel disease. This loss may lead to impaired binding of basic fibroblast growth factor and a reduced rate of ulcer healing. We suggest that heparin restores high-affinity receptor binding of basic fibroblast growth, and so increases the rate of mucosal recovery.

Carboxypeptidase D is a potential candidate to carry out redundant processing functions of carboxypeptidase E based on comparative distribution studies in the rat central nervous system

Post-translational processing is essential for the biological activation of many proteins and peptides. After precursor cleavage at specific single residues or pairs of basic residues by the proprotein convertases, the C-terminal basic residues are removed. Carboxypeptidase E was thought to be the only enzyme responsible. Recent studies with carboxypeptidase E-deficient mice, Cpe(fat)/Cpe(fat), indicated the existence of carboxypeptidase E-like carboxypeptidases, such as carboxypeptidase D. In order to define potential redundant functions in vivo, we compared the distributions of both carboxypeptidases in the rat central nervous system and selected endocrine tissues. Carboxypeptidase D messenger RNA was abundantly expressed in glial cells in the gray and white matter, while neurons in several brain regions, such as the piriform cortex, basolateral amygdala and hippocampus, also expressed high levels of carboxypeptidase D messenger RNA. Co-localization of carboxypeptidases E and D messenger RNAs was observed in many brain regions, the spinal cord and endocrine tissues. Immunohistochemistry showed the intracellular distribution of carboxypeptidase D with a perinuclear pattern. The extensive distribution of carboxypeptidase D in both glial and neuronal cells indicates the important role of carboxypeptidase D in peptide processing, possibly working together with furin, a ubiquitously expressed proprotein convertase. The co-localization of carboxypeptidases D and E suggests that carboxypeptidase D may, at least partially, compensate for carboxypeptidase E processing functions in Cpe(fat)/Cpe(fat) mice.

Fever and acute brief psychosis in urban and rural settings in north India

BACKGROUND

This case-control study used data from Chandigarh, North India to investigate the association between antecedent fever and acute brief psychosis.

AIMS

To assess whether antecedent fever may be a biological correlate of acute brief psychosis, and contribute to the nosology of acute brief psychosis.

METHOD

The study was based in an incidence cohort from two catchment areas, an urban and a rural site, that were part of the World Health Organization Determinants of Outcome study. The cases (n = 17) met criteria for acute brief psychosis; controls (n = 40) were patients with other acute and subacute psychoses. The Life Events Schedule was used to determine the presence of antecedent fever.

RESULTS

The crude odds ratio for fever as a risk factor for acute brief psychosis was 6.2 (P = 0.004). The odds ratio in a logistic regression analysis--adjusted for site, gender and CATEGO classification--was 11.2 (P = 0.003).

CONCLUSIONS

Antecedent fever may be a biological correlate of acute brief psychosis. This finding supports the validity of this entity, and has implications for its aetiology and diagnosis.

Laser optical feedback tomography

We describe a new method for imaging in three-dimensional turbid media, laser optical feedback tomography. This technique is based on the resonant sensitivity of a short-cavity laser to frequency-shifted optical feedback from ballistic photons retrodiffused from the medium. The advantage of the method is that the detector is the laser source itself, which provides optical amplification with self-aligned spatial and temporal coherent detection.

Assessment of combined movements of the lumbar spine in asymptomatic and low back pain subjects using a three-dimensional electromagnetic tracking system

Combined movement examination (CME) is used by physiotherapists to assess and treat patients with low back pain (LBP). However, this method has not been subjected to quantitative assessment. The purpose of this study was to discover if CME of the lumbar spine could be measured with acceptable intra-examiner reliability and to make a preliminary investigation of the effect of LBP on the results of CME. Combined movement examination of the human thoracolumbar spine was measured using a three-dimensional electromagnetic goniometer (3SPACE Fastrak Polhemus, Colchester, Vermont, USA). 1. Intra-examiner reliability of CME was evaluated using a test-retest design; examination was repeated in 23 subjects without LBP and 16 with LBP. 2. A sample of 31 subjects without LBP and 23 subjects with LBP underwent CME, which involved measuring right and left sideflexion in the flexed, neutral and extended position. Pearson's r and the intraclass correlation coefficient for all variables ranged from 0.79 to 0.93 (P < 0.05). A MANOVA test (P < 0.05), comparing the combined effects of the two variables for each position, was used to test for a difference between the positions attained by the subjects with LBP and those without. Generally LBP subjects showed smaller ranges of movement than those without LBP. Each position was recorded as a degree of rotation around the x-axis (flexion/extension) and around the y-axis (left and right sideflexion). CME can be carried out with acceptable intra-examiner reliability; preliminary evidence is presented concerning the effectiveness of CME in identifying reduced spinal movement in LBP subjects.

The detection of brief daytime sleep episodes

INTRODUCTION

In the present study we evaluated the characteristics of sleep-onset detection (during daytime nap opportunities) as a function of differing sleep lengths among healthy, asymptomatic subjects.

METHODS

Twenty subjects were randomized into a Latin square design in which each subject received 1, 5, 10, and 20 minutes of sleep during an MSLT. Subjects were asked after each nap if they fell asleep. The rate of sleep detection was analyzed as a function of sleep duration.

RESULTS

Three subjects detected sleep onset after 1 minute of sleep, 7 subjects after 5 minutes of sleep, 10 subjects after 10 minutes of sleep, and 14 after 20 minutes of sleep (chi 2 = 9.63, p < .05).

CONCLUSIONS

The present data indicate the importance of sleep duration in an individual's ability to detect the occurrence of sleep. Importantly, only three subjects detected sleep after 1 minute of sleep, emphasizing the dangerous nature of brief sleep episodes in the context of public safety.

The behavioral morbidity of obstructive sleep apnea

The behavioral morbidity associated with obstructive sleep apnea (OSA) includes symptoms of excessive daytime sleepiness (EDS), neurocognitive deficits, psychological problems, and possibly an increased chance of accidents. EDS is among the most frequently reported symptoms in patients diagnosed with OSA. The available data suggest that the primary cause of EDS is sleep fragmentation. The subjective measures of sleepiness include the sleep wake activity inventory and the epworth sleepiness scale. Sleepiness can also be evaluated objectively in the sleep laboratory using the multiple sleep latency test or the maintenance of wakefulness test. The neurocognitive manifestations of OSA include impairments in vigilance, concentration, memory, and executive function. There is no agreed on consensus as to how to best quantify neurocognitive deficits in this population. Symptoms consistent with depression or personality changes have also been described, but are likely to be correlates of EDS and/or the chronicity of the disorder. Manifestations of the behavioral morbidity of OSA are reversible, but dependent on the degree of normalization in sleep-disordered breathing and the individual's sleep habits.

Patient based methods for assessing adverse events in clinical trials in rheumatology. Progress report for the OMERACT Drug Toxicity Working Party. Outcome Measures in Rheumatology

There has been increasing recognition in recent years that the measurement of drug related toxicities in rheumatology clinical trials has been sub-optimal. The OMERACT Drug Toxicity Working Party was established to address this issue. The first task of the working party was to identify a minimum set of attributes of drug related toxicity that would be important to patients, clinicians, investigators, and policymakers. The working party then developed consensus on a standard set of properties for instruments to measure these attributes. Existing instruments in the field of rheumatology were ascertained by literature review and by contact with experts in the field. Four instruments were ascertained and evaluated using the guidelines developed by the working party. This report outlines the progress and preliminary results of these activities.

Absent or low expression of the zeta chain in T cells at the tumor site correlates with poor survival in patients with oral carcinoma

Immunohistology for expression of the CD3zeta and CD3epsilon chains in TIL was performed in 138 paraffin-embedded primary oral squamous cell carcinoma tissues and 10 nontumor, inflammatory lesions. Semiquantitative analysis of the staining intensity for zeta chain expression and number of zeta chain expression-positive cells distinguished tumors with absent or low zeta expression (42 of 132) from those with normal zeta expression (90 of 132). Zeta chain expression was inversely correlated with the tumor stage. Survival was significantly lower in patients whose TIL had absent or low zeta expression, controlling for stage (P = 0.003) and lymph node status (P = 0.0005). The prognostic value of zeta chain was restricted to patients with stage III or IV tumors (P = 0.003). The data indicate that absent or decreased zeta expression in TIL combined with tumor stage or nodal status defines a group of patients with oral squamous cell carcinoma who have an extremely poor prognosis.

Neuroendocrine protein 7B2 is essential for proteolytic conversion and activation of proprotein convertase 2 in vivo

The 7B2 protein is widely distributed in neural and endocrine tissues. Its biological function was found to be related to the processing enzyme proprotein convertase 2 (PC2), a mammalian subtilisin/kexin-like endoproteinase that cleaves at specific single or multiple basic amino-acid residues. In order to examine the proposed function of 7B2 on PC2 in in vivo models, we first compared the distribution of 7B2 and PC2 mRNAs in the rat brain. Expression of 7B2 mRNA was found to be pan-neuronal, but additionally, we observed 7B2 mRNA in ependymal cells and in the subcommissural organ. Although the expression of PC2 mRNA was exclusively neuronal, it was more restricted, sparing some regions expressing high levels of 7B2. This finding suggests that 7B2 has an additional function in non-PC2-expressing cells. No evidence of PC2-positive/7B2-negative cells could be obtained in the adult rat brain. However, in the developing rat brain (E17), such regions were easily observed, showing higher levels of pro-PC2 (75 kD). Similarly, in the animal model of insulin-induced hypoglycemic shock, where adrenomedullary 7B2 expression is decreased, the ratio of pro-PC2 to mature PC2 (75 kD:68 kD) was observed to be increased. Finally, the human neuroepithelioma SK-N-MCIXC expresses PC2 but not 7B2. Accordingly, only inactive pro-PC2 forms were observed: 75-kD intracellular and 71-kD extracellular. After stable transfection of SK-N-MCIXC cells with 27-kD pro-7B2, mature and active (68-kD) PC2 was secreted into the medium. Our data demonstrate a critical role of 7B2 in the proteolytic conversion and activation of PC2 in vivo.

Does capsaicin affect physiologic and thermal responses of males during immersion in 22 degrees C?

BACKGROUND

Capsaicin alters thermoregulation in adult rats by producing a dose-dependent fall in body temperature and metabolism. The present investigation examined the thermal and metabolic responses in males who were fed capsaicin (CAP: 2 mg.kg(-1) body weight) vs. a placebo (PL: a maltodextrin capsule) prior to immersion in cold water.

METHODS

Seven Caucasian males aged 20-28 yr were immersed in 22 degrees C twice (PL vs. CAP), for 120 min. The following were examined: metabolism (M; W.m(-2)), rectal temperature (Tre; degrees C), mean skin temperature (Tsk; degrees C), tissue insulation (I; degrees C.m(-2).W(-1) and proportion of energy derived from carbohydrate (%CHO).

RESULTS

For M, Tre, I, and Tsk there was no significant differences between treatments (PL vs. CAP) when the variables were pooled jointly over time. However, significant differences across time was detected for Tre (p = 0.0003), Tsk (p = 0.0147), and M (p = 0.0036). Values for %CHO demonstrate a main effect for treatment (p = 0.0210) suggesting the CAP (46.7-/+25.9%) treatment demonstrated a decreased reliance on carbohydrate utilization for energy provision as compared to the PL (75.0+/-21.9%) treatment. Additionally, the treatment x time interaction was significant (p = 0.0096) whereby, PL differed from CAP at 5 min only.

CONCLUSION

From these data it appears that while M, Tre, and Tsk differed across time, a CAP (which differentially affected percent of energy derived from carbohydrate) feeding did not differentially affect the thermal and metabolic responses of males during acute cold water immersion.

Molecular cloning and tissue distribution of rat sarcosine dehydrogenase

Sarcosine dehydrogenase (SarDH) is a mitochondrial flavoenzyme involved in the oxidative degradation of choline to glycine. The absence of SarDH activity in humans is genetically transmitted and is the cause of an amino acid metabolism disorder called sarcosinemia. Tryptic fragments of the purified enzyme from rat liver were subjected to Edman degradation and the sequences obtained were used to clone the cDNA encoding the full length protein. The deduced amino acid sequence of SarDH shares an overall similarity of 47% with dimethylglycine dehydrogenase (Me2GlyDH), another flavoenzyme involved in the mitochondrial choline catabolism with a similar FAD-binding domain. Covalent binding of FAD to SarDH was demonstrated by the observation of strong fluorescence at 530 nm under excitation at 450 nm of the enzyme immunoprecipitated under denaturing conditions from liver extracts. The localization of SarDH immunoreactivity in the mitochondrial matrix was confirmed by Western-blot analysis of purified mitochondrial fractions. Finally, the tissue distribution of SarDH was investigated by Northern-blot analysis of total RNA and Western-blot analysis of total protein from several rat tissues. A strong expression in the liver, but also in the lung, pancreas, kidney, thymus, and oviduct was observed. We therefore suggest that the enzymes of the choline catabolism pathway are important also for metabolism in nonhepatic tissues.

Identification of mouse CPX-2, a novel member of the metallocarboxypeptidase gene family: cDNA cloning, mRNA distribution, and protein expression and characterization

A novel member of the metallocarboxypeptidase gene family was identified from its homology with carboxypeptidase E and has been designated CPX-2. The cDNA of 2500 nucleotides encodes a protein of 764 amino acids that contains an N-terminal signal peptide-like sequence, a 158-residue discoidin domain, and a 400-residue carboxypeptidase domain. The 400-residue metallocarboxypeptidase domain has 59% amino acid identity with a protein designated AEBP-1; 44% to 46% identity with carboxypeptidases E, N, and Z; and lower homology with other members of the metallocarboxypeptidase gene family. The discoidin domain of CPX-2 has 22% amino acid identity with the carbohydrate-binding domain of discoideum-I, 29% to 34% identity with the phospholipid-binding domain of human factors V and VIII, and 59% identity with the discoidin-like domain on AEBP-1. CPX-2 is missing several of the predicted active-site residues that are conserved in most other members of the metallocarboxypeptidase gene family and which are thought to be required for enzyme activity. Expression of CPX-2 using the baculovirus system produced several forms of protein, from 80 to 105 kDa, but no detectable activity toward a variety of carboxypeptidase substrates. A shorter 50-kDa form of CPX-2, which contains the carboxypeptidase domain but not the discoidin domain, was also inactive when expressed in the baculovirus system. CPX-2 is able to bind to Sepharose-Arg; this binding is blocked by 10 mM Arg. Northern blot analysis showed CPX-2 mRNA in mouse brain, liver, kidney, and lung. In situ hybridization analysis of brain revealed a broad distribution. Areas that are enriched in CPX-2 include the hippocampus, cerebral cortex, median eminence, and choroid plexus. Taken together, these data suggest a widespread function for CPX-2, possibly as a binding protein rather than an active carboxypeptidase.

Daytime CPAP titration: a viable alternative for patients with severe obstructive sleep apnea

OBJECTIVE

Continuous positive airway pressure (CPAP) is the treatment of choice for patients diagnosed with severe obstructive sleep apnea (OSA). The implementation of CPAP therapy has traditionally been based on full-night titration studies or split-night protocols. This study compared a group of patients who received a regular nocturnal CPAP titration with patients who received a daytime CPAP titration. The objective of the study was to determine if daytime CPAP titration is a viable alternative for the implementation of CPAP treatment in patients with severe OSA.

STUDY DESIGN

Fourteen patients (13 men and one woman) received a daytime CPAP titration (day group). The day group was matched to 18 patients (17 men and one woman) who were titrated under a full-night regular nocturnal study (night group). Eligible patients were those with severe OSA (respiratory event index > 40). The groups were matched by age, sex, and body mass index.

RESULTS

Daytime and nocturnal CPAP titration studies yielded sufficient amounts of rapid eye movement (REM) and non-REM sleep to help determine CPAP settings. Importantly, the diurnal and nocturnal CPAP titrations resulted in comparable therapeutic pressures as well as comparable resolution of sleep-disordered breathing. After 1 week of treatment, the groups exhibited similar CPAP use and comparable improvements in subjective sleepiness as indicated by their increase in sleep/wake activity inventory scores.

CONCLUSIONS

Daytime CPAP titration studies may be a viable alternative for the efficient and expedient implementation of CPAP therapy among some patients with severe OSA.

Lymphatic mapping with isosulfan blue dye in squamous cell carcinoma of the head and neck

OBJECTIVE

To determine whether intraoperative lymphatic mapping with isosulfan blue dye and sentinel lymph node biopsy accurately demonstrates the pathway of regional metastases from mucosal sites in squamous cell carcinoma of the head and neck.

DESIGN

A prospective clinical study of intraoperative lymphatic mapping.

SETTING

An academic tertiary referral center.

PATIENTS

Patients with previously untreated squamous cell carcinoma of the head and neck whose surgical treatment included neck dissection.

INTERVENTION

Injection of isosulfan blue dye into the mucosa surrounding squamous cell carcinomas of the upper aerodigestive tract during cervical lymphadenectomy.

OUTCOME MEASURES

Correlation of the pathologic findings in the blue sentinel lymph node with those in the remaining cervical lymphatics.

RESULTS

No blue-stained cervical lymphatics were identified after injection of the mucosa surrounding the primary squamous cell carcinoma with isosulfan dye.

CONCLUSION

The technique of intraoperative lymphatic mapping with isosulfan blue dye requires further study before it can be used for the detection of occult cervical metastases in squamous cell carcinoma of the head and neck.

Colocalization of heparin and receptor binding sites on keratinocyte growth factor

Keratinocyte growth factor (KGF) is a member of the fibroblast growth factor (FGF) family. FGFs are also known as heparin-binding growth factors because they bind to heparin and their physical and biological properties are modulated by heparin. Consistent with a role as a paracrine effector, KGF is produced by cells of mesenchymal origin but is active primarily, if not exclusively, on epithelial cells. KGF is involved in a variety of physiological processes, including proliferation, differentiation, wound healing, and cytoprotection. To identify regions in KGF that contribute to heparin and tyrosine kinase receptor interactions, nine peptides spanning defined motifs in the predicted structure of KGF were synthesized, and their heparin and receptor binding properties were analyzed. Peptides at the amino and carboxyl termini bound heparin, and one peptide showed relative binding comparable to that of KGF. Competitive binding studies showed that this peptide along with two other overlapping peptides specifically displaced KGF bound to the KGF receptor. These three peptides were also selectively recognized by a neutralizing monoclonal antibody against KGF, though only in the presence of heparin. Together, these data suggest that the sites for heparin and receptor binding both reside in the amino and carboxyl termini of KGF, which are spatially juxtaposed in the predicted three-dimensional structure of this molecule.

Levels of TGF-alpha and EGFR protein in head and neck squamous cell carcinoma and patient survival

BACKGROUND

The most accurate predictor of disease recurrence in patients treated for head and neck squamous cell carcinoma is, at present, the extent of regional lymph node metastasis. Since elevated levels of epidermal growth factor receptor (EGFR) and of its ligand, transforming growth factor-alpha (TGF-alpha), have been detected in primary tumors of patients with head and neck squamous cell carcinoma, we determined whether tumor levels of these proteins were of prognostic importance.

METHODS

Monoclonal antibodies specific for EGFR and TGF-alpha were used for immunohistochemical detection of each protein in tissue sections of primary tumors from 91 patients who were treated by surgical resection. Levels of immunoreactive EGFR and TGF-alpha were quantified by use of a computerized image analysis system and were normalized to appropriate standards. The logrank test and proportional hazards regression analysis were used to calculate the probability that EGFR and TGF-alpha levels were associated with disease-free survival (i.e., no recurrence of cancer) and cause-specific survival (i.e., patients do not die of their disease). All P values were two-sided.

RESULTS

When tumor levels of EGFR or TGF-alpha were analyzed as continuous variables, disease-free survival and cause-specific survival were reduced among patients with higher levels of EGFR (both P = .0001) or TGF-alpha (both P = .0001). In a multivariate analysis, tumor site, tumor level of EGFR, and tumor level of TGF-alpha were statistically significant predictors of disease-free survival; in a similar analysis, regional lymph node stage and tumor levels of EGFR and of TGF-alpha were significant predictors of cause-specific survival.

CONCLUSION

Quantitation of EGFR and TGF-alpha protein levels in primary head and neck squamous cell carcinomas may be useful in identifying subgroups of patients at high risk of tumor recurrence and in guiding therapy.