Cytologic features of focal papillary thyroid carcinoma arising within follicular adenoma: a masked cytomorphologic analysis of 17 cases.

BACKGROUND/OBJECTIVE: Focal papillary thyroid carcinoma (PTC) arising within a follicular adenoma (PTCFA) represents a clinically significant, but rare, histopathologic subset of papillary carcinomas whose cytologic features have not been well described. This uncommon presentation of PTC may contribute to a subset of thyroid aspirates interpreted as 'atypia of undetermined significance/follicular lesion of undetermined significance' (AUS/FLUS). STUDY DESIGN: Seventeen fine-needle aspiration biopsy (FNAB) cases diagnosed as 'PTCFA' on corresponding surgical excision were identified from the archival records of 2 large academic medical centers. A control group of 40 FNAB comprised of 20 follicular adenomas (FA) and 20 PTC was identified (based on the corresponding surgical pathology diagnosis) for comparison. All 57 FNAB were reviewed in a masked fashion and scored for a series of 31 cytomorphologic features. The intraclass correlation between diagnostic categories and overall agreement between cytopathologists was statistically evaluated. RESULTS: Aspirates of PTCFA were originally diagnosed as 'negative' (n = 3), 'AUS/FLUS' (n = 7), 'suspicious for a follicular neoplasm' (n = 3), 'suspicious for malignancy' (n = 3), and 'malignant' (n = 1). On masked review, the most common cytomorphologic features of PTCFA were a nonmacrofollicular cytoarchitectural pattern (71%), medium-large cell size (74%), and micronucleoli (79%). Intranuclear pseudoinclusions and a papillary architecture were absent in 85 and 88% of the cases, respectively. Relative to the 2 control groups, the PTCFA cases demonstrated overlapping features between FA and PTC for the majority of the 31 examined cytomorphologic features. CONCLUSION: PTCFA represent a rare subset of PTC that is difficult to recognize as PTC by FNAB. Most cases exhibit overlapping features between a benign thyroid nodule and conventional PTC, and they are often interpreted as 'AUS/FLUS'.

The insulin-like growth factor I receptor is overexpressed in psoriatic epidermis, but is differentially regulated from the epidermal growth factor receptor.

Insulin-like growth factor I (IGF-I)/somatomedin C is an important mediator of keratinocyte growth in vitro, and the expression of IGF-I receptors in the basal layer of normal epidermis suggests that this growth pathway may function in the regulation of keratinocyte growth in vivo as well. The pattern of IGF-I receptor expression in normal skin is distinct from that of the epidermal growth factor (EGF) receptor, suggesting that these receptors might be differentially regulated. The purpose of this study was to obtain a better understanding of IGF-I receptor function in the skin by examining IGF-I receptor expression in psoriatic epidermis and in cultured human keratinocytes. Our findings indicate that IGF-I receptor expression is increased in psoriasis as measured by protein tyrosine kinase assays of biopsy extracts and by immunohistochemical staining with an IGF-I receptor-specific monoclonal antibody. Unlike EGF receptor expression, which is also increased in psoriatic epidermis, the pattern of IGF-I receptor expression corresponds closely with the increased size of the keratinocyte proliferative compartment in psoriasis. Biochemical agents that diminish EGF receptor ligand binding (phorbol ester or calcium ionophore treatment) produce opposite effects on the IGF-I receptor. These results suggest that cellular expression and differential regulation of both growth factor receptor systems may control critical aspects of epidermal proliferation or function.

The structure of abelsonite.

Abelsonite, a C(31) nickel-porphyrin of the deoxophylloerythroetioporphyrin type, is shown to have methyl groups in the 2, 3, 7, 12, and 18 positions and ethyl groups in the 8 and 17 positions by high-resolution, high-field (1)H nuclear magnetic resonance and nuclear Overhauser effect studies. Removal of the nickel by treatment with methanesulfonic acid permitted confirmation of the structure on the free base porphyrin and demonstrated structural integrity under the conditions required for demetallation. The structure is best accounted for geochemically by the hypothesis that abelsonite is derived from a chlorophyll.

Single amino acid substitutions in EGF-like elements of Notch and Delta modify Drosophila development and affect cell adhesion in vitro.

Notch locus EGF-like element mutations spl, altering eye development, and AxE2, affecting wing and sensilla development, are modified by mutations at Delta. It is shown that two allele-specific suppressors of spl involve single amino acid substitutions in the 4th (Dlsup5) and 9th (Dlsup4) EGF-like elements of the Delta protein. Cultured cells producing spl or AxE2 aggregate with cells producing wild-type Delta or Dlsup5 protein, and Dlsup5-producing cells adhere to cells producing wild-type Notch protein. However, spl,AxE2, and Dlsup5 are each defective in promoting these cell affinities, as none of the mutant proteins can compete with the corresponding wild-type proteins for formation of cell aggregates. Thus, widely separated EGF-like elements of Notch and Delta appear to participate in functional molecular interactions between the proteins. Dlsup5 does not improve adhesiveness of spl in vitro, so suppression in vivo may involve altered developmental signaling by spl-Dlsup5 complexes, rather than modified cell adhesion.

Human keratinocytes are a major source of cutaneous platelet-derived growth factor.

PDGF has been implicated as one of the principal mitogens involved in cutaneous wound healing. While it has been previously reported that both platelets and monocytes are a source of PDGF in human dermal wound repair, the production of PDGF by human keratinocytes has not yet been described. In this manuscript, we report the production of PDGF by cultured human keratinocytes. Both PDGF A and B chain mRNA can be detected in cultured cells. While only PDGF-AA polypeptide is found in significant levels in keratinocyte-conditioned culture media, all three PDGF isoforms (AA, AB, and BB) are present in detergent-solubilized cell extracts. No evidence of PDGF receptor expression was observed in cultured keratinocytes when analyzed for either mRNA levels or polypeptide expression, suggesting that PDGF does not play an autocrine role in keratinocyte growth. Analysis of cryosections of human cutaneous wounds by immunostaining for PDGF showed that both PDGF A and B chain is constitutively expressed in normal epidermis, as well as in newly reconstituted wound epidermis. No evidence for PDGF receptor polypeptide expression in the epidermis was detected by immunostaining of cryosections.

Purification and crystallization of thymidine kinase from herpes simplex virus type 1.

Thymidine kinase from herpes simplex virus type 1 (ATP:thymidine 5'-phosphotransferase; EC 2.7.1.21) has been purified from an overexpression system and crystallized against ammonium sulfate by using the hanging-drop technique. The tetragonal crystals are of space group P4122 or P4322, and have unit cell dimensions a = b = 84 A, c = 180 A.

Synergistic effects of epidermal growth factor (EGF) and insulin-like growth factor I/somatomedin C (IGF-I) on keratinocyte proliferation may be mediated by IGF-I transmodulation of the EGF receptor.

The epidermal growth factor (EGF) receptor pathway is an important mediator of keratinocyte growth in vitro and both receptor and ligand components of this pathway are abnormally expressed in hyperproliferative epidermis. The purpose of this study was to examine interactions between the EGF receptor pathway and the insulin-like growth factor I/somatomedin C (IGF-I) receptor pathway in modulating the growth of cultured normal human keratinocytes. Short-term growth of keratinocytes in a chemically defined medium demonstrated that neither EGF nor IGF-I alone could support significant keratinocyte spreading or proliferation, but that a combination of EGF with IGF-I or high-dose insulin could. IGF-I or high-dose insulin transmodulates keratinocyte EGF receptor expression via the IGF-I receptor in a dose- and time-dependent manner, increasing EGF receptor binding an average of 1.8 times up to a maximum of fourfold without altering EGF binding affinity. Staining of normal human epidermis with an IGF-I receptor specific monoclonal antibody demonstrates that IGF-I receptors localize to the basal proliferative cell compartment, suggesting that IGF-I receptor and EGF receptor pathway interactions may play a role in the regulation of epidermal growth and in the pathogenesis of hyperproliferative skin diseases.

Anthralin decreases keratinocyte TGF-alpha expression and EGF-receptor binding in vitro.

Anthralin is an effective topical treatment for active psoriasis; however, its mechanism of action is unknown. Both TGF-alpha and its receptor, the EGF receptor, are overexpressed in active psoriatic plaques and might, therefore, play a role in psoriatic epidermal hyperplasia. In order to assess whether anthralin might act via alteration of this growth factor pathway, we examined the in vitro effects of pharmacologic concentrations of anthralin on cultured normal human keratinocytes. Keratinocyte proliferation was inhibited by 98% at an anthralin concentration of 10 ng/ml. In contrast, lymphocyte proliferation was inhibited by only 50% at an anthralin concentration of 10 micrograms/ml. Anthralin treatment did not induce cell-cycle-specific growth arrest as assessed by flow-cytometric analysis of acridine-orange-stained keratinocytes. Northern analysis of anthralin-treated keratinocytes demonstrated a marked decrease in TGF-alpha mRNA expression. Anthralin-treated keratinocytes showed decreased binding of 125I-EGF and 125I-IGF-I to their respective receptors, but EGF receptor binding was inhibited to a greater extent. Anthralin decreased ligand-binding affinity and cell-surface numbers of EGF receptors as assessed by Scatchard analysis of 125I-EGF binding to anthralin-treated keratinocytes. These results indicate that anthralin alters components of the EGF receptor pathway in cultured keratinocytes and that these effects might contribute to the clinical efficacy of anthralin in the treatment of active psoriasis.

Role of growth factors, cytokines, and their receptors in the pathogenesis of psoriasis.

Psoriasis is characterized by epidermal hyperplasia, altered epidermal maturation, and local accumulation of acute and chronic inflammatory cells. Keratinocyte hyperplasia in psoriasis may be explained in part by overproduction of growth factors or cytokines which stimulate epidermal proliferation and by altered metabolism of growth-factor receptors in affected skin. Psoriatic epidermis displays overproduction of TGF-alpha and interleukin-6 (IL-6), factors produced by keratinocytes and other cell types in psoriatic skin. TGF-alpha and IL-6 are mitogens for normal human keratinocytes and act via specific receptors. The TGF-alpha receptor (EGF receptor) is overexpressed in psoriatic epithelium and its altered expression could be caused in part by gamma interferon which prevents normal receptor down-regulation in response to EGF binding. Several phenotypic features of the psoriatic keratinocyte, including growth activation and expression of HLA-DR, gamma-IP-10, ICAM-1, and other molecules, are best explained as resulting from the combined effects of TGF-alpha, IL-6, and gamma interferon (and possibly other cytokines) on epidermal keratinocytes. The multiple histologic features of psoriasis, including epidermal hyperplasia and accumulation of acute and chronic inflammatory cells, may be mediated by defined growth factors and cytokines that are produced in psoriatic skin and affect the function of diverse cell types.

Increased dermal expression of platelet-derived growth factor receptors in growth-activated skin wounds and psoriasis.

Platelet-derived growth factor (PDGF) is a potent mitogenic and chemotactic factor for fibroblasts and other cell types. PDGF effects are mediated by binding of PDGF to dimeric PDGF receptors possessing intrinsic tyrosine kinase activity. We examined the expression pattern of PDGF receptors in cryostat sections of normal and growth-activated human skin using a monoclonal antibody, PR7212, specific for the beta subunit of the PDGF receptor. PDGF receptors were expressed at low levels in normal skin, with only occasional staining of dermal connective tissue cells. In contrast, PDGF receptor expression was greatly elevated in the dermis of growth-activated skin from 15 chronic wounds and 10 psoriatic lesions. PDGF receptors were increased in dermal fibroblasts and in dermal blood vessels in both conditions. Immunoblot analysis confirmed the increased expression of beta-subtype PDGF receptors in psoriatic lesional tissue. PDGF receptors were not detected in normal or growth-activated epidermis. Differential expression of PDGF receptors could regulate increased proliferation of vascular and connective tissue cells observed in psoriasis and chronic wounds.

In vivo tissue pharmacokinetics by fluorine magnetic resonance spectroscopy: a study of liver and muscle disposition of fleroxacin in humans.

Magnetic resonance spectroscopy of fluorine (19F) has been used to noninvasively study the in vivo pharmacokinetics of a model drug, fleroxacin (a fluoroquinolone antibiotic agent), in healthy human subjects. After oral administration, fleroxacin was detected in 19F magnetic resonance spectra from both liver and calf muscle and four magnetic resonance examinations were undertaken during a 24-hour period. By combining plasma analysis by high performance liquid chromatography with the magnetic resonance data, the following pharmacokinetic parameters (mean values) were obtained: tmax, 1.4, 4.6, and 5.6 hours in liver, plasma, and muscle, respectively; Cmax, 53, about 250, and about 60 mumol/L in plasma, liver, and muscle, respectively; t1/2, 4.4 hours (fast phase) and 10.8 hours (slow phase) in liver and 14.2 hours in plasma. The study documents for the first time the potential use of 19F magnetic resonance spectroscopy to noninvasively observe the time-related changes of a fluorine-containing drug in human tissues after oral administration.

Extensively keratinized squamous intraepithelial lesions of the cervix are difficult to grade.

We tested the hypothesis that extensively keratinized squamous intraepithelial lesions (SILs) are difficult to grade precisely by identifying 100 Papanicolaou smears with a keratinizing SIL that had been originally judged difficult to grade. Of these, 65 were confirmed as low-grade SIL (LSIL) or high-grade SIL (HSIL) on subsequent biopsy. The 65 smears were reviewed independently by 3 cytopathologists who graded each case as LSIL or HSIL (by Bethesda System criteria). The accuracy of the grade was determined by the subsequent biopsy results; accuracy was compared with that of a historic control group of SILs with biopsy follow-up. In the study group, biopsies showed LSIL in 41 cases and HSIL in 24. The mean accuracy for a smear diagnosis of LSIL was 60% for the study group and 92% for the control group. For a smear diagnosis of HSIL, the accuracy was 60% for the study group and 95% for the control group. The overall kappa value for the study group confirmed poor interobserver agreement. Some keratinizing SILs are difficult if not impossible to grade precisely using standard criteria. For such lesions, the diagnosis "SIL, grade cannot be determined due to extensive keratinization" is justified.

Subclassifying atypical squamous cells in Thin-Prep cervical cytology correlates with detection of high-risk human papillomavirus DNA.

Recent studies have proposed subclassifying ASCUS into "favor reactive" (ASFR), "not otherwise specified" (ASNOS), and "favor squamous intraepithelial lesion (SIL)" (ASFS). This study explored the reproducibility of these diagnoses with Thin-Prep cytology and their association with high-risk human papillomavirus DNA (HRHPV). Three pathologists and 1 cytotechnologist with 2 to 25 years of experience reviewed 144 Thin-Prep (Cytyc, Boxborough, MA) specimens previously diagnosed as normal, ASFR, ASNOS, ASFS, and SIL. Interobserver reproducibility was computed with the kappa statistic. The original laboratory diagnosis was compared with the presence of HRHPV types. Interobserver reproducibility for a normal or SIL diagnosis was very good (kappa = .68 and .63). Reproducibility for ASFR, ASNOS, and ASFS ranged from poor to fair (kappa = .21, .19, and .32). In a weighted analysis, kappa values for ASFR/ASNOS and ASFS/SIL were .36 and .62, respectively. HRHPV-positivity for preparations originally diagnosed as N, ASFR, ASNOS, ASFS, and SIL were 5.7%, 8.8%, 17.4%, 47.8%, and 54.5%, respectively. The difference in index of HRHPV for either N or ASFR and ASFS or SIL was significant (P < .001). Reproducibility for ASCUS is generally poor, but better reproducibility is obtained by combining ASFS with SIL and, to a lesser degree, ASNOS with ASFR. ASFS and SIL confer a similar index of HRHPV and merit similar management. ASFR may be managed with cytologic follow-up; but this may depend upon the individual laboratory. HPV testing, in conjunction with cytologic and biopsy follow-up, appears useful for estimating the significance of ASCUS subgroups in laboratory practice.

Engineering analysis of penile hemodynamic and structural-dynamic relationships: Part I--Clinical implications of penile tissue mechanical properties.

PURPOSE: The least investigated physical determinant of penile rigidity has been penile tissue material properties. The goals in this study (Part I) were to define two penile mechanical parameters, cavernosal expandability X and tunical distensibility VE/VF, determine their magnitudes in humans and develop an analytical expression for penile volume as a function of these two tissue characteristics and intracavernosal pressure. METHODS: Dynamic infusion pharmacocavernosometry was performed in 21 impotent patients (age 43 +/- 19 y) to provide human geometric, hemodynamic and structural data. A mathematically derived model of hemodynamic and structural-dynamic characteristics of penile erection was developed (Parts I, II, III) incorporating penile tissue mechanical qualities. RESULTS: Cavernosal expandability X provided a measure of the ability to approach maximum volume at relatively low intracavernosal pressures. Tunical distensibility VE/VF denoted the maximal erect to flaccid penile volume ratio. The magnitudes of X and VE/VF in the study population were 0.04-0.17 mmHg-1 and 1.7-5.0 respectively. CONCLUSIONS: Enabling penile volume to be derived as a function of tissue mechanical characteristics and pressure, allows for penile rigidity to be expressed (in Part II) as a function of pressure, geometry and tissue qualities.

Improved convection compensating pulsed field gradient spin-echo and stimulated-echo methods.

The need for convection compensating methods in NMR has been manifested through an increasing number of publications related to the subject over the past few years (J. Magn. Reson. 125, 372 (1997); 132, 13 (1998); 131, 126 (1998); 118, 50 (1996); 133, 379 (1998)). When performing measurements at elevated temperature, small convection currents may give rise to erroneous values of the diffusion coefficient. In work with high resolution NMR spectroscopy, the application of magnetic field gradients also introduces an eddy-current magnetic field which may result in errors in phase and baseline in the FFT-spectra. The eddy current field has been greatly suppressed by the application of bipolar magnetic field gradients. However, when introducing bipolar magnetic field gradients, the pulse sequence is lengthened significantly. This has recently been pointed out as a major drawback because of the loss of coherence and of NMR-signal due to transverse relaxation processes. Here we present modified convection compensating pulsed field gradient double spin echo and double stimulated echo sequences which suppress the eddy-current magnetic field without increasing the duration of the pulse sequences.

Cyclosporine in psoriasis treatment. Inhibition of keratinocyte cell-cycle progression in G1 independent of effects on transforming growth factor alpha/epidermal growth factor receptor pathways.

Cyclosporine, an immunosuppressive drug, is effective in the treatment of recalcitrant psoriasis. Previous work suggested that keratinocyte hyperproliferation and inflammation are linked in psoriasis and that immune mechanisms participate in the pathogenesis of psoriasis. Transforming growth factor (TGF) alpha may be an important regulatory factor of epidermal growth as overproduction of TGF-alpha is associated with epidermal hyperplasia in psoriatic plaques and epidermal growth factor receptors are overexpressed in psoriatic epithelium. In this study, the effects of cyclosporine on cultured human keratinocytes were examined. Cyclosporine specifically inhibited keratinocyte cell-cycle progression in the G1 phase without causing keratinocytes to terminally differentiate. Cyclosporine did not decrease the expression of TGF-alpha or epidermal growth factor receptors. These results suggest that the effects of cyclosporine on psoriatic skin are unrelated to direct effects on autocrine growth regulation of keratinocytes via TGF-alpha production or of epidermal growth factor receptor modulation.

First direct demonstration of preferential release of citrate from astrocytes using [13C]NMR spectroscopy of cultured neurons and astrocytes.

Primary cultures of cerebral cortical neurons or astrocytes or the two cell types together (co-cultures) were incubated with [1-13C]glucose for 20 or 48 h. Subsequently, perchloric acid (PCA) extracts of the cells as well as redissolved lyophilized media were subjected to NMR spectroscopy in order to detect 13C-labeled amino acids (glutamine, glutamate, gamma-aminobutyrate (GABA)) and other metabolites (lactate, tricarboxylic acid cycle (TCA) constituents). NMR spectra of PCA extracts of neurons or co-cultures exhibited distinct peaks for glutamate and GABA whereas the PCA extracts of astrocytes and co-cultures showed peaks corresponding to glutamine and glutamate. This pattern is consistent with the neuronal location of the GABA synthesizing enzyme glutamate decarboxylase and the astrocytic localization of the glutamine synthesizing enzyme, glutamine synthetase. NMR spectra of the incubation media showed clearly that 13C-labeled citrate, alanine and glutamine were synthesized and released from astrocytes since only media from the astrocyte cultures or co-cultures or neurons and astrocytes contained these metabolites in detectable amounts. It may be concluded that astrocytes play an important role supplying neurons with precursors for biosynthesis of glutamate and GABA such as glutamine and TCA cycle constituents. Since among the latter only citrate could be found in significant amounts it may be hypothesized that this may be the quantitatively most important TCA constituent to be released from astrocytes and subsequently utilized by neurons.

Early changes in the 1H-NMR plasma spectrum in patients following breast surgery.

The composite methylene (chemical shift between 1.2-1.4 ppm) and methyl (0.8-0.9 ppm) resonances of the 1H-nuclear magnetic resonance (NMR) spectrum were analysed in plasma samples drawn pre- and post-surgery from patients treated for benign or malignant breast tumor. Using a 500 MHz NMR instrument operating at 25 degrees C, the resonances were analysed for line width at half-height and then averaged. The amounts of triglyceride (TG), cholesterol, apolipoproteins A1 (ApoA1) and B (ApoB) were measured in each sample. One week post-surgery, the high-field shoulder of the aliphatic peaks decreased and the composite peaks were weighted down-field compared with spectra obtained pre-surgery. The average line width in patients with malignant tumor observed 1 week post-surgery was narrower than pre-surgery (30.5 +/- 3.9 vs 38.1 +/- 4.2 Hz) (P = 0.01). Line widths observed 1 day post-surgery were not significantly different from pre-surgery values in either patient group. Comparing the methylene and methyl composite peaks, the narrowing in line width observed 1 week post-surgery was more pronounced for the methylene than the methyl line width. The ratio between the height of the composite methylene and methyl peaks was higher 1 week post-surgery (ratio, 2.12 +/- 0.23) than pre-surgery (1.79 +/- 0.37) (P = 0.03), indicative of a relative increase in triglyceride-rich lipoproteins. Compared with pre-surgery levels, TG was higher (1.8 +/- 0.3 vs 1.5 +/- 0.4 mmol/l) (P = 0.05) and ApoA1 lower (1.32 +/- 0.14 vs 1.43 +/- 0.12 g/l) (P = 0.02) 1 week post-surgery. One day post-surgery, decreased levels of lipids and apoliproteins were found. In conclusion, the line narrowing is explained as an effect of the surgical trauma itself. A less contribution to the composite line from high-density (HDL) relative to very-low-density (VLDL) lipoprotein is suggested as one mechanism for line width narrowing observed after surgery.

Metabolite composition in breast tumors examined by proton nuclear magnetic resonance spectroscopy.

BACKGROUND: In vivo characterisation of breast tumors using protein (1H) MR spectroscopy relies upon in vitro interpretation of tissue samples. The present study has investigated metabolite composition in extracts from breast tumors and non-involved breast tissue. Multivariate data analysis was used to determinate combinations of metabolites important for differentiation. MATERIALS AND METHODS: Tumor and non-involved breast tissue were obtained from 16 patients undergoing surgical treatment. 1H NMR spectra of perchloric acid tissue extracts were obtained at a BRUKER Avance DRX600 spectrometer. The data was analysed using principal component analysis and probabilistic neural networks. RESULTS: Low levels of glucose and high content of choline compounds were dominant findings in the tumor spectra. Principal component loadings demonstrated this strong association. The spectra were correctly classified using neural network analysis. CONCLUSIONS: Large differences in the metabolite composition of breast tumors and surrounding breast tissues have been documented.

Analysis and classification of proton NMR spectra of lipoprotein fractions from healthy volunteers and patients with cancer or CHD.

Human blood plasma samples from 52 subjects were collected and the very low density lipoprotein (VLDL), intermediate density lipoprotein (IDL), low density lipoprotein (LDL) and high density lipoprotein were isolated by serial ultra centrifugation. 600 MHz 1H NMR spectra of the lipoprotein fractions were acquired. The methyl and methylene regions in the spectra of VLDL, LDL and HDL were utilised in further analyses via Kohonen neural networks (KNN) and generative topographic mapping (GTM), two related examples of (unsupervised learning) self-organising feature mapping techniques. Systematic variations in lipoprotein profiles can be substantially visualised through the use of KNN and GTM. The relationship between the sample positions in the Kohonen plot was visualised by surface plots of the corresponding VLDL and HDL cholesterol and VLDL triglyceride contents. The GTM maps of the VLDL and HDL fractions were used to investigate the individual properties of selected samples. A large number of the cancer patients were found clustered in the VLDL GTM map, and GTM map positions of samples in relation to CHD, diabetes and renal failure could be found. Although the study group here considered is heterogeneous in respect to age, sex, type of disease and medications within each defined class, classification of VLDL and HDL data with probabilistic neural network (PNN) was quite successful with respect to the groupings: cancer, CHD, volunteers and other (comprising patients with other diseases). Statistics based on 15 independent sets of PNN calculations gave true positive fractions usually higher than 0.83 and false positive fractions lower than 0.088. Attempts to use the corresponding LDL data and four classes were uniformly poor although some classifications (e.g., volunteer versus CHD) were easily performed.